Symmetric Counterpart Research Articles

Pullout strength of pedicle screws using cadaveric vertebrae with or without artificial demineralization

OBJECTIVESTo evaluate the differences in the pullout strength and displacement of pedicle screws in cadaveric thoracolumbar vertebrae with or without artificial demineralization. METHODSFive human lumbar and five thoracic vertebrae from one cadaver were divided into two hemivertebrae. The left-side specimens were included in the simulated osteopenic model group and the right-side bones in a control group. In the model group, we immersed each specimen in HCl (1 N) solution for 40 minutes. We measured bone mineral density (BMD) using dual-energy X-ray absorptiometry and quantitative computerized tomography. We inserted polyaxial pedicle screws into the 20 pedicles of the cadaveric lumbar and thoracic spine after measuring the BMD of the 2 hemivertebrae of each specimen. We measured the pullout strength and displacement of the screws before failure in each specimen using an Instron system. RESULTSThe average pullout strength of the simulated osteopenic model group was 76% that of the control group. In the control and model groups, the pullout strength was 1678.87±358.96 N and 1283.83±341.97 N, respectively, and the displacement was 2.07±0.34 mm and 2.65±0.50 mm, respectively (p<.05). We detected positive correlations between pullout strength and BMD in the control group and observed a negative correlation between displacement and BMD in the model group. CONCLUSIONSBy providing an anatomically symmetric counterpart, the human cadaveric model with or without demineralization can be used as a test bed for pullout tests of the spine. In the simulated osteopenic model group, pullout strength was significantly decreased compared with the untreated control group. CLINICAL SIGNIFICANCEDecreased bone mineral density may significantly reduce the pullout strength of a pedicle screw, even though the range is osteopenic rather than osoteoporotic.

A Comparison of Analog Performance, Linearity, and Distortion Characteristics Between Symmetric InGaAs and Asymmetric InGaAs/InP MOSFETs

In this article, we report an investigation of analog performance, linearity, and harmonic distortion (HD) characteristics for both symmetric and asymmetric InGaAs n-channel MOSFETs at elevated temperatures. Analog performance parameters such as transconductance and voltage gain are found to be better for the asymmetric InGaAs MOSFETs than their symmetric counterparts. The linearity metrics such as g <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m2</sub> , g <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m3</sub> , voltage intercept points 2 (VIP2), VIP3, IIP3, and third-order intermodulation distortion (IMD3) have been analyzed. Asymmetric devices are found to perform better in terms of linearity. Moreover, distortion is also found to be less for the asymmetric devices than the symmetric ones. A comparison of the linearity and distortion characteristics of InGaAs devices with a similarly sized Si device reveals that, although the Si device performs better in terms of linearity, particularly at elevated temperatures, InGaAs devices have an edge in terms of distortion over the Si device.

Unified Expression of the Quasi-Static Electromagnetic Field: Demonstration With MEG and EEG Signals.

Objective:Electromagnetic recordings are useful for non-invasive measurement of human brain activity. They typically sample electric potentials on the scalp or the magnetic field outside the head using electroencephalography (EEG) or magnetoencephalography (MEG), respectively. EEG and MEG are not, however, symmetric counterparts: EEG samples a scalar field via a line integral over the electric field between two points, while MEG samples projections of a vector-valued field by small sensors. Here we present a unified mathematical formalism for electromagnetic measurements, leading to useful interpretations and signal processing methods for EEG and MEG.Methods:We represent electric and magnetic fields as solutions of Laplace’s equation under the quasi-static approximation, each field representable as an expansion of the same vector spherical harmonics (VSH) but differently weighted by electro- and magnetostatic multipole moments, respectively.Results:We observe that the electric and the magnetic fields are mathematically symmetric but couple to the underlying electric source distribution in distinct ways via their corresponding multipole moments, which have concise mathematical forms. The VSH model also allows us to construct linear bases for MEG and EEG for signal processing and analysis, including interference suppression methods and system calibration.Conclusion:The VSH model is a powerful and simple approach for modeling quasi-static electromagnetic fields.Significance:Our formalism provides a unified framework for interpreting resolution questions, and paves the way for new processing and analysis methods.

A connection between linearized Gauss–Bonnet gravity and classical electrodynamics II: Complete dual formulation

In a recent publication, a procedure was developed which can be used to derive completely gauge invariant models from general Lagrangian densities with [Formula: see text] order of derivatives and [Formula: see text] rank of tensor potential. This procedure was then used to show that unique models follow for each order, namely classical electrodynamics for [Formula: see text] and linearized Gauss–Bonnet gravity for [Formula: see text]. In this paper, the nature of the connection between these two well-explored physical models is further investigated by means of an additional common property; a complete dual formulation. First, we give a review of Gauss–Bonnet gravity and the dual formulation of classical electrodynamics. The dual formulation of linearized Gauss–Bonnet gravity is then developed. It is shown that the dual formulation of linearized Gauss–Bonnet gravity is analogous to the homogenous half of Maxwell’s theory; both have equations of motion corresponding to the (second) Bianchi identity, built from the dual form of their respective field strength tensors. In order to have a dually symmetric counterpart analogous to the nonhomogenous half of Maxwell’s theory, the first invariant derived from the procedure in [Formula: see text] can be introduced. The complete gauge invariance of a model with respect to Noether’s first theorem, and not just the equation of motion, is a necessary condition for this dual formulation. We show that this result can be generalized to the higher spin gauge theories, where the spin-[Formula: see text] curvature tensors for all [Formula: see text] are the field strength tensors for each [Formula: see text]. These completely gauge invariant models correspond to the Maxwell-like higher spin gauge theories whose equations of motion have been well explored in the literature.

17.1 %‐Efficient Eco‐Compatible Organic Solar Cells from a Dissymmetric 3D Network Acceptor

AbstractTo elevate the performance of polymer solar cells (PSC) processed by non‐halogenated solvents, a dissymmetric fused‐ring acceptor BTIC‐2Cl‐γCF3 with chlorine and trifluoromethyl end groups has been designed and synthesized. X‐ray crystallographic data suggests that BTIC‐2Cl‐γCF3 has a 3D network packing structure as a result of H‐ and J‐aggregations between adjacent molecules, which will strengthen its charge transport as an acceptor material. When PBDB‐TF was used as a donor, the toluene‐processed binary device realized a high power conversion efficiency (PCE) of 16.31 %, which improved to 17.12 % when PC71ThBM was added as the third component. Its efficiency of over 17 % is currently the highest among polymer solar cells processed by non‐halogenated solvents. Compared to its symmetric counterparts BTIC‐4Cl and BTIC‐CF3‐γ, the dissymmetric BTIC‐2Cl‐γCF3 integrates their merits, and has optimized the molecular aggregations with excellent storage and photo‐stability, and also extending the maximum absorption peak in film to 852 nm. The devices exhibit good transparency indicating a potential utilization in semi‐transparent building integrated photovoltaics (ST‐BIPV).

17.1 %-Efficient Eco-Compatible Organic Solar Cells from a Dissymmetric 3D Network Acceptor.

To elevate the performance of polymer solar cells (PSC) processed by non-halogenated solvents, a dissymmetric fused-ring acceptor BTIC-2Cl-γCF3 with chlorine and trifluoromethyl end groups has been designed and synthesized. X-ray crystallographic data suggests that BTIC-2Cl-γCF3 has a 3D network packing structure as a result of H- and J-aggregations between adjacent molecules, which will strengthen its charge transport as an acceptor material. When PBDB-TF was used as a donor, the toluene-processed binary device realized a high power conversion efficiency (PCE) of 16.31 %, which improved to 17.12 % when PC71ThBM was added as the third component. Its efficiency of over 17 % is currently the highest among polymer solar cells processed by non-halogenated solvents. Compared to its symmetric counterparts BTIC-4Cl and BTIC-CF3 -γ, the dissymmetric BTIC-2Cl-γCF3 integrates their merits, and has optimized the molecular aggregations with excellent storage and photo-stability, and also extending the maximum absorption peak in film to 852 nm. The devices exhibit good transparency indicating a potential utilization in semi-transparent building integrated photovoltaics (ST-BIPV).

SymmetryNet

We study the problem of symmetry detection of 3D shapes from single-view RGB-D images, where severely missing data renders geometric detection approach infeasible. We propose an end-to-end deep neural network which is able to predict both reflectional and rotational symmetries of 3D objects present in the input RGB-D image. Directly training a deep model for symmetry prediction, however, can quickly run into the issue of overfitting. We adopt a multi-task learning approach. Aside from symmetry axis prediction, our network is also trained to predict symmetry correspondences. In particular, given the 3D points present in the RGB-D image, our network outputs for each 3D point its symmetric counterpart corresponding to a specific predicted symmetry. In addition, our network is able to detect for a given shape multiple symmetries of different types. We also contribute a benchmark of 3D symmetry detection based on single-view RGB-D images. Extensive evaluation on the benchmark demonstrates the strong generalization ability of our method, in terms of high accuracy of both symmetry axis prediction and counterpart estimation. In particular, our method is robust in handling unseen object instances with large variation in shape, multi-symmetry composition, as well as novel object categories.

Superiority of an Asymmetric Perylene Diimide in Terms of Hydrosolubility, G-Quadruplex Binding, Cellular Uptake, and Telomerase Inhibition in Prostate Cancer Cells.

Perylene diimide (PDI) derivatives have been studied as G-quadruplex ligands that suppress telomerase activity by facilitating G-quadruplex formation of telomeric DNA and the hTERT promoter. PIPER, the prototypical PDI, reduces telomerase activity in lung and prostate cancer cells, leading to telomere shortening and cellular senescence of these cells. However, PIPER suffers from poor hydrosolubility and the propensity to aggregate at neutral pH. In this report, we synthesized a new asymmetric PDI, aPDI-PHis, which maintains one N-ethyl piperidine side chain of PIPER and has histidine as another side chain. The results show that aPDI-PHis is superior to its symmetric counterparts, PIPER and PDI-His, in terms of hydrosolubility, G-quadruplex binding, cellular uptake, and telomerase inhibition in prostate cancer cells. These results suggest that one N-ethyl piperidine side chain of PDI is sufficient for G-quadruplex binding, while another side chain can be tuned to elicit desirable properties. These findings might lead to better PDIs for use as anticancer drugs.

Consumer responses toward symmetric versus asymmetric facial expression emojis

Facial expression emojis are commonly used in digital communications and marketing campaigns. However, it is less known how the design of emojis may affect consumer responses. To address this gap, this research examines the impact of emojis’ facial asymmetry levels on consumer judgments. Findings across four studies demonstrate that compared with their symmetric counterparts, asymmetric facial expression emojis are more likely to receive favorable consumer evaluations. This effect is driven by perceptions of human expression resemblance and emotional expression strength and tends to be more prominent among consumers with a higher level of emotional sensitivity. Moreover, marketing messages including an asymmetric (vs. a symmetric) emoji are more likely to generate positive consumer responses.

Influence of Double Entry Volute on Incidence Angle Variation Under Steady Flow: Numerical Investigation

EGR extraction from one side of the exhaust manifold creates imbalance of mass flow in a double entry turbine. To overcome this problem, the asymmetric double entry turbine was introduced. The performance maps of this turbine were obtained through extensive test configurations in both steady and unsteady flow conditions at Imperial College cold flow test rig. Two main configurations were investigated; nozzleless and nozzle vane setting. Nevertheless, no attempt has been made to compare the performance of asymmetric double entry turbine to that of the symmetric counterpart. One way to make comparison between these two double entry turbine volutes, is by using numerical simulation. This is achieved by using ANSYS CFX tool in this paper. A symmetric double entry volute CAD model is developed using the same A/R ratio as the asymmetric counterpart, adopting the same mixed flow rotor, inlet and exit ducts. The steady state numerical investigation was conducted at two turbine speeds, 30k RPM and 48k RPM, for the nozzleless configuration. Steady state experimental results of asymmetric double entry turbine are set as the boundary condition in the simulation. Validation of the simulation results with that of the experimental data, shows good agreements for both speed lines for the asymmetric double entry turbine. The symmetric double entry turbine recorded peak efficiencies; lower by 2.8% and 8%, at 30k RPM and 48k RPM respectively, compared to that of asymmetric double entry turbine. The results of steady state conditions of the asymmetric double entry turbine suggest that the distribution of the incidence angle is better than the symmetric double entry turbine as it is able to maintain the incidence angle at off-design and design point operating condition within the same range.

Gravitational deflection of light and shadow cast by rotating Kalb-Ramond black holes

The nonminimal coupling of the nonzero vacuum expectation value of the self-interacting antisymmetric Kalb-Ramond field with gravity leads to a power-law hairy black hole having a parameter $s$, which encompasses the Reissner$-$Nordstrom black hole ($s=1$). We obtain the axially symmetric counterpart of this hairy solution, namely, the rotating Kalb-Ramond black hole, which encompasses, as special cases, Kerr ($s=0$) and Kerr-Newman ($s=1$) black holes. Interestingly, for a set of parameters ($M, a$, and $\Gamma$), there exists an extremal value of the Kalb-Ramond parameter ($s=s_{e}$), which corresponds to an extremal black hole with degenerate horizons, while for $s<s_{e}$, it describes a nonextremal black hole with Cauchy and event horizons, and no black hole for $s>s_{e}$. We find that the extremal value $s_e$ is also influenced by these parameters. The black hole shadow size decreases monotonically and the shape gets more distorted with an increasing $s$; in turn, shadows of rotating Kalb-Ramond black holes are smaller and more distorted than the corresponding Kerr black hole shadows. We investigate the effect of the Kalb-Ramond field on the rotating black hole spacetime geometry and analytically deduced corrections to the light deflection angle from the Kerr and Schwarzschild black hole values. The deflection angle for Sgr A* and the shadow caused by the supermassive black hole M87* are included and compared with analogous results of Kerr black holes. The inferred circularity deviation $\Delta C\leq 0.10$ for the M87* black hole merely constrains the Kalb-Ramond field parameter, whereas shadow angular diameter $\theta_d=42\pm 3\, \mu$as, within the $1\sigma$ region, places bounds $\Gamma\leq 0.09205$ for $s=1$ and $\Gamma\leq 0.02178$ for $s=3$.

Asymmetrically noncovalently fused-ring acceptor for high-efficiency organic solar cells with reduced voltage loss and excellent thermal stability

Abstract Simultaneously broadening the spectral response and reducing the energy loss are challenging tasks in the material design of organic solar cells (OSCs). Herein, a novel asymmetrically noncovalently fused-ring electron acceptor (NFEA) with unilateral alkylthio-substituted thiophene π-bridge, namely IDST-4F, is synthesized. IDST-4F exhibits a broader absorption, higher-lying energy levels, larger dipole moments and suppressed crystallinity than its symmetric counterpart (ID-4F) without the π-bridge. Compared to the devices of PM6:ID-4F, the optimized PM6:IDST-4F-based devices display simultaneously enhanced current density and photovoltage, resulting in an excellent power conversion efficiency (PCE) of 14.3%, which is the highest value among the OSCs based on NFEAs reported in the literature to date. More importantly, the PM6:IDST-4F-based OSCs possess excellent thermal stability with 82% of the initial PCE after thermal treatment at 150 °C for 1200 min. In summary, this study indicates that asymmetrically NFEAs are promising to achieve high efficiency with excellent thermal stability.

Topology of tensor ranks

We study path-connectedness and homotopy groups of sets of tensors defined by tensor rank, border rank, multilinear rank, as well as their symmetric counterparts for symmetric tensors. We show that over C, the set of rank-r tensors and the set of symmetric rank-r symmetric tensors are both path-connected if r is not more than the complex generic rank; these results also extend to border rank and symmetric border rank over C. Over R, the set of rank-r tensors is path-connected if it has the expected dimension but the corresponding result for symmetric rank-r symmetric d-tensors depends on the order d: connected when d is odd but not when d is even. Border rank and symmetric border rank over R have essentially the same path-connectedness properties as rank and symmetric rank over R. When r is greater than the complex generic rank, we are unable to discern any general pattern: For example, we show that border-rank-three tensors in R2⊗R2⊗R2 fall into four connected components. For multilinear rank, the manifold of d-tensors of multilinear rank (r1,…,rd) in Cn1⊗…⊗Cnd is always path-connected, and the same is true in Rn1⊗…⊗Rnd unless ni=ri=∏j≠irj for some i∈{1,…,d}. Beyond path-connectedness, we determine, over both R and C, the fundamental and higher homotopy groups of the set of tensors of a fixed small rank, and, taking advantage of Bott periodicity, those of the manifold of tensors of a fixed multilinear rank. We also obtain analogues of these results for symmetric tensors of a fixed symmetric rank or a fixed symmetric multilinear rank.

Inelastic seismic behavior of asymmetric structures under bidirectional ground motion: An effort to incorporate the effect of bidirectional interaction in load resisting elements

Seismically driven asymmetric structures are more vulnerable than their symmetric counterparts because of the coupling of lateral and torsional vibration. Though the research effort has been made to study the behavior of asymmetric structures, however, studies under the bidirectional ground motion of such structures are extremely terse. Further, in the inelastic range, the interaction between seismic forces under bidirectional ground motion may influence the yield criteria, inelastic excursion, and displacement demand considerably. In this context, the present paper is an effort to study the influence of bidirectional interaction, which occurs in reality under two orthogonal components of ground motion in real seismic events for asymmetric structures. A recently developed, adequate bidirectional hysteresis model that is capable of capturing the effects of bidirectional interaction is used. The governing equation of motion is solved by step by step integration following Newmark’s β-γ method. For improving the accuracy, iterations are carried out in each time step applying the Newton-Raphson technique. The spring force updates at the end of each time step to account for material nonlinearity with reasonable accuracy. Further, the present study not only helps to develop physical insights into the behavior of asymmetric systems but also shows that inelastic response may be grossly underestimated if the interaction between seismic forces along two principal directions is not incorporated. The broad conclusions developed in the study may be a help to fine-tune the provision for asymmetric structures in seismic code.

Experimental and numerical investigation on the complex behaviour of the localised seismic response in a multi-storey plan-asymmetric structure

Asymmetric structures experience higher seismic damage compared with their symmetric counterparts. This damage is mainly attributed to the coupled torsional vibrations, which tend to induce twisting in the structural floors and increase the shear demands in the corner column of the flexible side (CCFE) of asymmetric structures with in-plan stiffness eccentricity. Such floor twisting consequently leads towards the damage concentration in the critical region of CCFE and produce relatively higher local deformations and stiffness degradation of the structural component. Therefore, the investigation of such damage concentration is important as it can potentially lead towards local and global seismic failure. In this regard, this research aims at evaluating the damage behaviour of CCFE of a plan-asymmetric reinforced concrete (RC) structure. For this purpose, a quarter scaled asymmetric structure with in-plan stiffness eccentricity was experimentally tested under progressive seismic excitations. Internal seismic damage in the critical region of CCFE was monitored using Fibre Bragg grating (FBG) sensors during the structure’s transformation from elastic state to a highly plastic state. To validate the experimental findings, a calibrated finite element model was established in ABAQUS and a comparison of the damage behaviour of CCFE is presented to highlight the influence of stiffness eccentricity on damage concentration in the critical structural element. Finally, based on the experimental and numerical investigations, the mechanism of the local response behaviour both at the flexible and stiff edge of the plan-asymmetric structure is discussed and compared. This research concludes that CCFE in plan-asymmetric structures requires substantial design redundancy and special seismic detailing to resist extreme seismic events.

Asymmetric Siloxane Functional Side Chains Enable High-Performance Donor Copolymers for Photovoltaic Applications.

In this work, three benzodithiophene-benzotriazole alternated wide band gap copolymers attaching symmetric or asymmetric conjugated side chains, namely, PDBTFBTA-2T, PBDTFTBA-TSi, and PBDTFBTA-2Si, were developed for efficient nonfullerene polymer solar cells. The symmetry effect of the side chains was investigated in detail on the overall properties of these donor polymers. The results demonstrated that the introduced siloxane functional groups showed less effect on the absorption and frontier orbital levels of the prepared polymers but had a significant effect on the miscibility between these polymer donors and the nonfullerene acceptor. When increasing the content of siloxane functional groups, the miscibility of the polymer donors and Y6 would be improved, leading to the decreased domain size and more mixed domains. Interestingly, the active blend based on PBDTFTBA-TSi with asymmetric side chains exhibited more balanced miscibility, carrier mobility, and phase separation, benefiting exciton diffusion and dissociation. Therefore, a champion power conversion efficiency (PCE) of 14.18% was achieved finally in PBDTFTBA-TSi devices, which was 20.6 and 19.0% higher than the symmetric counterparts of PBTFBTA-2T devices (PCE = 11.76%) and PBDTFBTA-2Si devices (PCE = 11.92%), respectively. This work highlights that the asymmetric side-chain engineering based on siloxane functional groups is a promising design strategy for high-performance polymer donor semiconductors.

XGASS: Robust quantification of asymmetries in global H i spectra and their relationship to environmental processes

ABSTRACT We present an analysis of asymmetries in global H i spectra from the extended GALEX Arecibo SDSS Survey (xGASS), a stellar mass-selected and gas fraction-limited survey which is representative of the H i properties of galaxies in the local Universe. We demonstrate that the asymmetry in a H i spectrum is strongly linked to its signal-to-noise meaning that, contrary to what was done in previous works, asymmetry distributions for different samples cannot be compared at face value. We develop a method to account for noise-induced asymmetry and find that the typical galaxy detected by xGASS exhibits higher asymmetry than what can be attributed to noise alone, with 37 per cent of the sample showing asymmetry greater than 10 per cent at an 80 per cent confidence level. We find that asymmetric galaxies contain, on average, 29 per cent less H i mass compared to their symmetric counterparts matched in both stellar mass and signal-to-noise. We also present clear evidence that satellite galaxies, as a population, exhibit more asymmetric H i spectra than centrals and that group central galaxies show a slightly higher rate of H i asymmetries compared to isolated centrals. All these results support a scenario in which environmental processes, in particular those responsible for gas removal, are the dominant driver of asymmetry in xGASS.

Linear time algorithms for finding independent spanning trees on pyramid networks

The use of independent spanning trees (ISTs) has scientific applications in fault-tolerant requirement in network protocols and secure message distributions. Most of the designs of ISTs are for those interconnection networks with vertex symmetric property, implying that one can find ISTs rooted on a designated vertex, and, by the vertex symmetry property of the given network, hence have solved the ISTs problem on any arbitrary vertex. The existence of asymmetry makes the ISTs problem even harder than its symmetric counterpart. Cheriyan and Maheshwari (J Algorithms 9:507–537, 1988) showed that, for any 3-connected graph, 3-ISTs rooted at any vertex can be found in O(|V||E|) time. In this paper, we propose linear time algorithms that solved 3-ISTs rooted at an arbitrary vertex of pyramid networks.

Sensitive detection of cardiac troponin-I protein using fabricated piezoresistive microcantilevers by a novel method of asymmetric biofunctionalization

Microcantilever-based sensor platform has attracted a lot of attention over the time in detection of a variety of molecules due to their miniaturized dimensions. Sensitivity enhancement is an important aspect of such sensors, especially when used for point-of-care diagnostic purpose. However, the major concern while operating these sensors in deflection mode is their sensitivity which mainly relies on selective chemical modification protocols employed on these sensor surfaces. One of the ways of getting better sensitivity is through asymmetric (one side) biofunctionalization of the sensor surface. In the presented work here, we have demonstrated a novel approach of asymmetric biofunctionalization of proteins in overall sensitivity enhancement of piezoresistive silicon nitride-oxide microcantilever sensor platform inside a flow chamber. Herein, using our developed surface chemistry, asymmetrically biofunctionalized microcantilevers first exhibited a greater electrical response in terms of piezoresistance change than their symmetric counterpart in the detection of human immunoglobulins (HIgGs) protein. Finally, these microcantilevers were employed to exhibit the enhanced sensitivity towards the detection of a crucial cardiac marker protein, i.e. Troponin-I (cTnI) down to 250 ng ml−1 using asymmetric biofunctionalization process. This study shows that the developed asymmetric biofunctionalization methodology may be used as a general protocol to detect other important biomarkers of clinical applications with improved sensitivity.

Unidimensional continuous-variable measurement-device-independent quantum key distribution

Continuous-variable (CV) measurement-device-independent (MDI) quantum key distribution (QKD) is immune to imperfect detection devices, which can eliminate all kinds of attacks on practical detectors. Here we first propose a CV-MDI QKD scheme using unidimensional modulation (UD) in general phase-sensitive channels. The UD CV-MDI QKD protocol is implemented with the Gaussian modulation of a single quadrature of the coherent states prepared by two legitimate senders, aiming to simplify the implementation compared with the standard, symmetrically Gaussian-modulated CV-MDI QKD protocol. Our scheme reduces the complexity of the system since it ignores the requirement in one of the quadrature modulations as well as the corresponding parameter estimations. The security of our proposed scheme is analyzed against collective attacks, and the finite-size analysis under realistic conditions is taken into account. UD CV-MDI QKD shows a comparable performance to that of its symmetric counterpart, which will facilitate the simplification and practical implementation of the CV-MDI QKD protocols.