Emergence of Inequality in Income and Wealth Dynamics.

Increasing wealth inequality is a significant global issue that demands attention. While the distribution of wealth varies across countries based on their economic stages, there is a universal trend observed in the distribution function. Typically, regions with lower wealth values exhibit an exponential distribution, while regions with higher wealth values demonstrate a power-law distribution. In this review, we introduce measures that effectively capture wealth inequality and examine wealth distribution functions within the wealth exchange model. Drawing inspiration from the field of econophysics, wealth exchange resulting from economic activities is likened to a kinetic model, where molecules collide and exchange energy. Within this framework, two agents exchange a specific amount of wealth. As we delve into the analysis, we investigate the impact of various factors such as tax collection, debt allowance, and savings on the wealth distribution function when wealth is exchanged. These factors play a crucial role in shaping the dynamics of wealth distribution.

Surgical strategy for revisional lumbar pedicle subtraction osteotomy to correct fixed sagittal imbalance: The effect of the osteotomy level and iliac screw fixation.

BACKGROUND: More caudal osteotomy is believed to lead to greater sagittal correction; however, the osteotomy level and whether or not to use iliac screw fixation (ISF) are topics of on-going debate. The aim of this study was to compare clinical and radiographic outcomes after revisional lumbar pedicle subtraction osteotomy (PSO) for fixed sagittal imbalance (FSI) according to the osteotomy level and ISF. METHODS: All consecutive patients who underwent revisional PSO (at L3 or L4) for FSI in a single institute from July 2006 to January 2014 were investigated retrospectively. Thirty-eight patients with at least 2-year follow-up were finally included. Clinical outcomes including the visual analogue scale (VAS) and Oswestry Disability Index (ODI) were investigated. Radiographic spinopelvic parameters were analyzed according to the level of PSO, the degree of correction, and the use of ISF. RESULTS: The mean number of fused segments after PSO was 6.6 ± 1.8. Sagittal vertical axis (SVA) was restored after the surgery (12, 2.5, and 5.2 cm at preoperative, postoperative, and the last follow-up, respectively). PSO was performed at L3 in 16 patients and at L4 in 22 patients. The osteotomy level was not associated with any changes of spinopelvic parameters (pelvic tilt [PT] or lumbar lordosis) or sagittal alignment (T1-pelvic angle [TPA] or SVA). However, better TPA restoration was achieved with more osteotomy resection angle (P = 0.031). ISF group showed significant improvement in postoperative pelvic orientation (PT and ratio of PT to pelvic incidence) which was maintained until the last follow-up. CONCLUSIONS: Although postoperative sagittal alignment was different in FSI patients according to the osteotomy level, pelvic orientation improved in ISF group. Also, the degree of correction showed significant associations with sagittal alignment. When performing revisional PSO for FSI, spine surgeon should carefully consider how to correct rather than where to do the osteotomy, and the role of ISF.

Minimally Invasive Plate Osteosynthesis (MIPO) technique for complex tibial shaft fracture.

TTo evaluate the clinical and radiological results of the treatment of complex tibial shaft fracture (AO/OTA type 42-C) with minimally invasive plate osteosynthesis(MIPO). Twenty patients diagnosed with complex tibial shaft fracture without extension to the articular surface and treated with MIPO, including 9 cases of AO/OTA type 42-C2 and 11 cases of AO/OTA type 42-C3, 6 of which were open fractures. External fixation was used for open fractures until the soft tissue damage had healed; then, 2nd stage operation with MIPO was performed to stabilize the fracture. Each patient was followed up for a minimum of 12 months. The mean time to union was 20.1 weeks. Delayed union was observed in 4 cases. Angular deformity, length shortening and non-union were not observed. Severely comminuted and open fractures of the tibial shaft may benefit from temporary external fixation prior to performing MIPO.

Dual plate for comminuted proximal humerus fractures.

The purpose of this study is to evaluate radiological, clinical results and complication rates of dual plate fixation for severe metaphyseal comminuted fracture of proximal humerus. 21 patients who have proximal humerus fractures with impaired posteromedial buttress were enrolled. Fractures were treated with dual plate technique using Proximal Humeral Locking plate and Variable Angle Plate. Radiographic results were analyzed based on duration of union. For evaluation of the degree of anatomical reduction, neck shaft angle on the anteroposterior view was measured by simple plain radiography using the Paavolainen method, while anterior-posterior angulation was measured on the axial view. Degree of anatomic reduction was good in 17 patients (80.95%), fair in 3 patients (14.28%), and poor in 1 patient (4.77%). One case of impingement, and one case of avascular necrosis were noted. The dual plate technique provides stable fixation and satisfactory clinical and radiological results for severely comminuted metaphyseal fracture of the proximal humerus.

Efficient gene knockdown in Clostridium acetobutylicum by synthetic small regulatory RNAs.

Clostridium is considered a promising microbial host for the production of valuable industrial chemicals. However, Clostridium is notorious for the difficulty of genetic manipulations, and consequently metabolic engineering. Thus, much effort has been exerted to develop novel tools for genetic and metabolic engineering of Clostridium strains. Here, we report the development of a synthetic small regulatory RNA (sRNA)-based system for controlled gene expression in Clostridium acetobutylicum, consisting of a target recognition site, MicC sRNA scaffold, and an RNA chaperone Hfq. To examine the functional operation of sRNA system in C. acetobutylicum, expression control was first examined with the Evoglow fluorescent protein as a model protein. Initially, a C. acetobutylicum protein annotated as Hfq was combined with the synthetic sRNA based on the Escherichia coli MicC scaffold to knockdown Evoglow expression. However, C. acetobutylicum Hfq did not bind to E. coli MicC, while MicC scaffold-based synthetic sRNA itself was able to knockdown the expression of Evoglow. When E. coli hfq gene was introduced, the knockdown efficiency assessed by measuring fluorescence intensity, could be much enhanced. Then, this E. coli MicC scaffold-Hfq system was used to knock down adhE1 gene expression in C. acetobutylicum. Knocking down the adhE1 gene expression using the synthetic sRNA led to a 40% decrease in butanol production (2.5 g/L), compared to that (4.5 g/L) produced by the wild-type strain harboring an empty vector. The sRNA system was further extended to knock down the pta gene expression in the buk mutant C. acetobutylicum strain PJC4BK for enhanced butanol production. The PJC4BK (pPta-HfqEco ) strain, which has the pta gene expression knocked down, was able to produce 16.9 g/L of butanol, which is higher than that (14.9 g/L) produced by the PJC4BK strain, mainly due to reduced acetic acid production. Fed-batch culture of PJC4BK (pPta-HfqEco ) strain coupled with in situ gas stripping produced 105.5 g of total solvents (70.7 g butanol, 20.5 g acetone, and 14.3 g ethanol), demonstrating that the sRNA-based engineered C. acetobutylicum strain can be cultured without instability. The synthetic sRNA system reported in this study will be useful for more efficient development of engineered C. acetobutylicum strains capable of producing valuable chemicals and fuels. Biotechnol. Bioeng. 2017;114: 374-383. © 2016 Wiley Periodicals, Inc.

Studies of hot photoluminescence in plasmonically coupled silicon via variable energy excitation and temperature-dependent spectroscopy.

By integrating silicon nanowires (∼150 nm diameter, 20 µm length) with an Ω-shaped plasmonic nanocavity, we are able to generate broadband visible luminescence, which is induced by high order hybrid nanocavity-surface plasmon modes. The nature of this super bandgap emission is explored via photoluminescence spectroscopy studies performed with variable laser excitation energies (1.959 to 2.708 eV) and finite difference time domain simulations. Furthermore, temperature-dependent photoluminescence spectroscopy shows that the observed emission corresponds to radiative recombination of unthermalized (hot) carriers as opposed to a resonant Raman process.

Tailoring light-matter coupling in semiconductor and hybrid-plasmonic nanowires.

Understanding interactions between light and matter is central to many fields, providing invaluable insights into the nature of matter. In its own right, a greater understanding of light-matter coupling has allowed for the creation of tailored applications, resulting in a variety of devices such as lasers, switches, sensors, modulators, and detectors. Reduction of optical mode volume is crucial to enhancing light-matter coupling strength, and among solid-state systems, self-assembled semiconductor and hybrid-plasmonic nanowires are amenable to creation of highly-confined optical modes. Following development of unique spectroscopic techniques designed for the nanowire morphology, carefully engineered semiconductor nanowire cavities have recently been tailored to enhance light-matter coupling strength in a manner previously seen in optical microcavities. Much smaller mode volumes in tailored hybrid-plasmonic nanowires have recently allowed for similar breakthroughs, resulting in sub-picosecond excited-state lifetimes and exceptionally high radiative rate enhancement. Here, we review literature on light-matter interactions in semiconductor and hybrid-plasmonic monolithic nanowire optical cavities to highlight recent progress made in tailoring light-matter coupling strengths. Beginning with a discussion of relevant concepts from optical physics, we will discuss how our knowledge of light-matter coupling has evolved with our ability to produce ever-shrinking optical mode volumes, shifting focus from bulk materials to optical microcavities, before moving on to recent results obtained from semiconducting nanowires.

One-dimensional polaritons with size-tunable and enhanced coupling strengths in semiconductor nanowires.

Strong coupling of light with excitons in direct bandgap semiconductors leads to the formation of composite photonic-electronic quasi-particles (polaritons), in which energy oscillates coherently between the photonic and excitonic states with the vacuum Rabi frequency. The light-matter coherence is maintained until the oscillator dephases or the photon escapes. Exciton-polariton formation has enabled the observation of Bose-Einstein condensation in the solid-state, low-threshold polariton lasing and is also useful for terahertz and slow-light applications. However, maintaining coherence for higher carrier concentration and temperature applications still requires increased coupling strengths. Here, we report on size-tunable, exceptionally high exciton-polariton coupling strengths characterized by a vacuum Rabi splitting of up to 200 meV as well as a reduction in group velocity, in surface-passivated, self-assembled semiconductor nanowire cavities. These experiments represent systematic investigations on light-matter coupling in one-dimensional optical nanocavities, demonstrating the ability to engineer light-matter coupling strengths at the nanoscale, even in non-quantum-confined systems, to values much higher than in bulk.

Defect Passivation of 2D Semiconductors by Fixating Chemisorbed Oxygen Molecules via h-BN Encapsulations.

Hexagonal boron nitride (h-BN) is a key ingredient for various 2D van der Waals heterostructure devices, but the exact role of h-BN encapsulation in relation to the internal defects of 2D semiconductors remains unclear. Here, it is reported that h-BN encapsulation greatly removes the defect-related gap states by stabilizing the chemisorbed oxygen molecules onto the defects of monolayer WS2 crystals. Electron energy loss spectroscopy (EELS) combined with theoretical analysis clearly confirms that the oxygen molecules are chemisorbed onto the defects of WS2 crystals and are fixated by h-BN encapsulation, with excluding a possibility of oxygen molecules trapped in bubbles or wrinkles formed at the interface between WS2 and h-BN. Optical spectroscopic studies show that h-BN encapsulation prevents the desorption of oxygen molecules over various excitation and ambient conditions, resulting in a greatly lowered and stabilized free electron density in monolayer WS2 crystals. This suppresses the exciton annihilation processes by two orders of magnitude compared to that of bare WS2. Furthermore, the valley polarization becomes robust against the various excitation and ambient conditions in the h-BN encapsulated WS2 crystals.

Kirigami Photopiezo Catalysts for Self-Sustainable Environment Remediation.

Photo(electro)-piezo catalysis has emerged as one of the most effective strategies for sustainable environmental remediation. While various (nano)materials have been investigated for enhancing the intrinsic properties related to the interfacial band structure, increasing the efficiency by integration of materials with rational design for stress-strain applications has not yet been considered. Herein, we introduce kirigami strain engineering to photopiezo catalysts for enhancing efficiency by increasing the magnitude of applied strain and density of bends. Macroscale stretching motion is converted into localized bending by a pliable kirigami structure using similar or even lower input energy, which can be easily modulated by natural waves. The kirigami structure leads to a significant enhancement (∼250%) in the degradation of dyes, and we discovered the significant contribution of the oxygen reduction pathway in the charge-transfer mechanism, which corresponds to the observed enhancement. The photopiezo catalytic effects of kirigami were further highlighted by the small water reservoir test, showing its feasibility in nature for self-sustainable environmental remediation that can be modulated using motions of winds, waves, and life vibrations.

Simple and Reliable Magnetic Resonance Imaging Parameter to Predict Postoperative Ambulatory Function in Patients With Metastatic Epidural Spinal Cord Compression.

STUDY DESIGN: Retrospective case-control study. OBJECTIVES: The aim of this study was to develop a simple and reliable imaging parameter to predict postoperative ambulatory status in patients with metastatic epidural spinal cord compression (MESCC). METHODS: Sixty-three patients with MESCC underwent spine surgery because of neurologic deficits were included. On preoperative axial MRI, the cord compression ratio was analyzed for postoperative ambulatory status. The relationship between other imaging features, such as fracture of the affected vertebra and increased T2 signal intensity of the spinal cord at the compression level, and the postoperative ambulatory status were also analyzed. RESULTS: Cord compression ratio and increased T2 signal change of the spinal cord were significantly different between the postoperative ambulatory group and the non-ambulatory group. Receiver operating characteristic analysis showed that the optimal cut-off value was 0.84. In the multivariate regression analysis, only a cord compression ratio of more than 0.84 was significantly associated with postoperative ambulatory status (odds ratio = 10.80; 95% confidence interval = 2.79-41.86; P = .001). Interobserver/intraobserver agreements were strong for the cord compression ratio, however those agreements were weak for increased T2 signal intensity. CONCLUSIONS: On preoperative MRI, the cord compression ratio may predict postoperative ambulatory status in patients with MESCC. The measurement of this imaging parameter was simple and reliable. This imaging predictor may be helpful for both clinicians and patients.

Study on Rolling Defects of Al-Mg Alloys with High Mg Content in Normal Rolling and Cross-Rolling Processes.

This study investigated defect formation and strain distribution in high-Mg-content Al-Mg alloys during normal rolling and cross-rolling processes. The finite element analysis (FEA) revealed the presence of wave defects and strain localization-induced zipper cracks in normal cold rolling, which were confirmed by the experimental results. The concentration of shear strain played a significant role in crack formation and propagation. However, the influence of wave defects was minimal in the cross-rolling process, which exhibited a relatively uniform strain distribution. Nonetheless, strain concentration at the edge and center regions led to the formation of zipper cracks and edge cracks, with more pronounced propagation observed in the experiments compared to FEA predictions. Furthermore, texture evolution was found to be a crucial factor affecting crack propagation, particularly with the development of the Goss texture component, which was observed via electron backscattered diffraction analysis at bending points. The Goss texture hindered crack propagation, while the Brass texture allowed cracks to pass through. This phenomenon was consistent with both FEA and experimental observations. To mitigate edge crack formation and propagation, potential strategies involve promoting the formation of the Goss texture at the edge through alloy and process conditions, as well as implementing intermediate annealing to alleviate stress accumulation. These measures can enhance the overall quality and reliability of Al-Mg alloys during cross-rolling processes. In summary, understanding the mechanisms of defect formation and strain distribution in Al-Mg alloys during rolling processes is crucial for optimizing their mechanical properties. The findings of this study provide insights into the challenges associated with wave defects, strain localization, and crack propagation. Future research and optimization efforts should focus on implementing strategies to minimize defects and improve the overall quality of Al-Mg alloys in industrial applications.

Effects of bone cement augmentation for uppermost instrumented vertebra on adjacent disc segment degeneration in lumbar fusions.

OBJECTIVE: We investigated the long-term effects of bone cement-augmented instrumentation in multilevel lumbar fusions in a retrospective cohort study. The use of cement-augmented screws is one of the techniques used to reduce early mechanical failure in treating multilevel lumbar fusion, especially in the elderly. However, little information is available regarding the long-term effects. METHODS: A total of 51 patients who had undergone ≥3 levels of lumbar fusion were divided into two groups according to the use of bone cement-augmented screw fixation involving the upper instrumented vertebra: 22 patients in the cement-augmented group (group I) and 29 patients in the non-cement-augmented group (group II). Analysis of radiographic adjacent disc segment degeneration (ASD) revealed patients with lumbosacral fusion with a similar degree of osteoporosis. Radiologic ASD was defined as progression of >2 UCLA (University of California, Los Angeles) grades at 2 years postoperatively. Other sagittal parameters and the preoperative magnetic resonance imaging Pfirrmann grades at the adjacent levels, possibly related to ASD, were also analyzed. RESULTS: No significant differences were present in the preoperative demographic and radiographic parameters between the 2 groups. However, the postoperative kyphotic changes at 3 months were greater for the non-cement-augmented group. In terms of the long-term effects, the incidence of radiologic ASD (group I, n = 20 [95.2%]; vs group II, n = 15 [53.6%]) was significantly higher in the cement-augmented group. Logistic regression analysis of radiologic ASD, including other clinical and radiologic parameters, postoperative pelvic incidence-lumbar lordosis mismatch (odds ratio, 5.201; 95% confidence interval, 1.123-24.090; P = 0.035), and cement augmentation (odds ratio, 20.193; 95% confidence interval, 2.195-185.729; P = 0.008) showed a significant correlation with the development of radiologic ASD at 2 years postoperatively. CONCLUSIONS: Although bone cement-augmented screw implantation can prevent kyphotic deformation at the proximal junction of upper instrumented vertebra in the early postoperative stages of multilevel lumbar fusion, a careful selection of patients is required because of possibly accelerated degeneration of adjacent segments.

Tailoring hot-exciton emission and lifetimes in semiconducting nanowires via whispering-gallery nanocavity plasmons.

The manipulation of radiative properties of light emitters coupled with surface plasmons is important for engineering new nanoscale optoelectronic devices, including lasers, detectors and single photon emitters. However, so far the radiative rates of excited states in semiconductors and molecular systems have been enhanced only moderately, typically by a factor of 10-50, producing emission mostly from thermalized excitons. Here, we show the generation of dominant hot-exciton emission, that is, luminescence from non-thermalized excitons that are enhanced by the highly concentrated electromagnetic fields supported by the resonant whispering-gallery plasmonic nanocavities of CdS-SiO(2)-Ag core-shell nanowire devices. By tuning the plasmonic cavity size to match the whispering-gallery resonances, an almost complete transition from thermalized exciton to hot-exciton emission can be achieved, which reflects exceptionally high radiative rate enhancement of >10(3) and sub-picosecond lifetimes. Core-shell plasmonic nanowires are an ideal test bed for studying and controlling strong plasmon-exciton interaction at the nanoscale and opens new avenues for applications in ultrafast nanophotonic devices.

Polarization-insensitive broadband omni-directional anti-reflection in ZnO nanoneedle array for efficient solar energy harvesting.

Broadband omni-directional anti-reflection characteristics have been an important issue because they can maximize the optical absorption in photovoltaic devices. Here, we investigate the optical properties of ZnO nanoneedle arrays to demonstrate broadband anti-reflection, omni-directionality, and polarization insensitivity using optical simulations and experimental approaches. The results of this work clarify that the ZnO nanoneedle array plays an important role as a broadband anti-reflection layer due to its spatially graded refractive index, omni-directionality and polarization insensitivity. To take advantage of these structures, we prepared a ZnO nanoneedle array on the surface of conventional SiN x /planar Si solar cells to prove the broadband omni-directional anti-reflection for solar energy harvesting. Current density-voltage results show that SiN x /planar Si solar cells with ZnO nanoneedle arrays lead to a nearly 20% increase in power conversion efficiency compared to SiN x /planar Si solar cells, and a 9.3% enhancement in external quantum efficiency is obtained under identical conditions. Moreover, the photocurrent results of SiN x /planar Si solar cells with ZnO nanoneedle arrays clearly demonstrate the incident angle- and polarization-insensitive characteristics compared to those of typical SiN x /planar Si solar cells. Our results demonstrate the optical multi-functionality of ZnO nanoneedle arrays and pave the way for high-performance optoelectronic devices that require broadband omni-directional anti-reflection and polarization insensitivity.

Covalent Networking of a Conjugated-Polymer Photocatalyst to Promote Exciton Diffusion in the Aqueous Phase for Efficient Hydrogen Production.

A conjugated polymer particle in an aqueous phase is covalently networked in 3D by crosslinking with azide groups, leading to significantly enhanced activity-a high photocatalytic H2 evolution rate (11 024 µmol g-1 h-1 (λ > 420 nm)) and a high apparent quantum yield (up to 0.8%). The reaction between the photoactive azide and the alkyl chains of the conjugated polymer provides more intact intermolecular polymeric interactions in the colloidal state, thus preventing physical swelling and inhibiting the recombination of photoproduced carriers. The covalent network efficiently promotes exciton diffusion, which greatly facilitates charge separation and transfer. The azide photo-crosslinking also leads to more compact and better-packed nanoparticles in the aqueous phase and efficient transfer of excitons to the outer surface of the nanoparticles, where photocatalytic reactions occur. These results show that photo-crosslinking can suppress the adverse effects of alkyl chains which inhibit photocatalytic performance. Therefore, covalent crosslinking is a promising strategy for the development of solar and hydrogen energy.

Selective photocatalytic CO2 reduction to CH4 over metal-free porous polyimide in the solid-gas mode.

Using a catalyst-free one-pot polycondensation approach, a new donor-acceptor (D-A) based porous polyimide (PeTt-POP) photocatalyst was developed. PeTt-POP produced CH4 (125.63 ppm g-1 in 6 h) from CO2 under visible light irradiation in the gas-solid mode without the use of co-catalysts or sacrificial agents. The progress of the reaction and the corresponding intermediate species involved in the CO2 reduction were identified by operando DRIFTS experiments, from which a plausible reaction mechanism was proposed.

Galectin-3 binding protein promotes cell motility in colon cancer by stimulating the shedding of protein tyrosine phosphatase kappa by proprotein convertase 5.

It has previously been reported that shedding of the PTPκ ectodomain drives enhanced motility of colon cancer cells. Herein, we provide mechanism underlying the regulation of PTPκ shedding by galectin-3 binding protein. PTPκ was inarguably scissored by the processed form of proprotein convertase 5 (subtilisin/kexin type 5), and galectin-3 binding protein which is over-produced in colon cancer cells and tissues contributed to increased cancer cell motility by acting as a negative regulator of galectin-3 at the cell surface. The high expression ratio of galectin-3 binding protein to galectin-3 was clinically correlated to lymphatic invasion. These results suggest that galectin-3 binding protein may be a potential therapeutic target for treatment of, at least, colon cancer patients with high expression of galectin-3 binding protein.

Variable temperature spectroscopy of as-grown and passivated CdS nanowire optical waveguide cavities.

Semiconductor nanowire waveguide cavities hold promise for nanophotonic applications such as lasers, waveguides, switches, and sensors due to the tight optical confinement in these structures. However, to realize their full potential, high quality nanowires, whose emission at low temperatures is dominated by free exciton emission, need to be synthesized. In addition, a proper understanding of their complex optical properties, including light-matter coupling in these subwavelength structures, is required. We have synthesized very high-quality wurztite CdS nanowires capped with a 5 nm SiO(2) conformal coating with diameters spanning 100-300 nm using physical vapor and atomic layer deposition techniques and characterized their spatially resolved photoluminescence over the 77-298 K temperature range. In addition to the Fabry-Pérot resonator modulated emission from the ends of the wires, the low temperature emission from the center of the wire shows clear free excitonic peaks and LO phonon replicas, persisting up to room-temperature in the passivated wires. From laser scanning measurements we determined the absorption in the vicinity of the excitonic resonances. In addition to demonstrating the high optical quality of the nanowire crystals, these results provide the fundamental parameters for strong light-matter coupling studies, potentially leading to low threshold polariton lasers, sensitive sensors and optical switches at the nanoscale.

Proximal Junctional Kyphosis According to the Type of Lumbar Degenerative Kyphosis Following Lumbosacral Long Fusion.

STUDY DESIGN: A retrospective study. OBJECTIVE: The aim of this study was to investigate proximal junctional kyphosis (PJK) after lumbosacral long fusion according to preoperative Roussouly and lumbar degenerative kyphosis (LDK) types. SUMMARY OF BACKGROUND DATA: Although previous studies have suggested some risk factors for PJK, the effects of preoperative grade of sagittal imbalance and paraspinal muscles degeneration on PJK remain unclear. METHODS: Eighty-seven patients who had undergone lumbosacral fusion more than five levels with available clinical and radiological data were enrolled. The presence of PJK defined as sagittal Cobb angle ≥20° between the uppermost instrumented vertebra (UIV) and two supra-adjacent vertebrae at postoperative 2-year radiographs was recorded. Its occurrence was compared according to preoperative Roussouly and LDK types (Takemistu type) and the degree of paraspinal muscle degeneration at the upper level of UIV. Other sagittal radiographic parameters were also measured. RESULTS: In this series, 28 patients (group I, 32.2%) showed radiological PJK, whereas 59 patients did not show radiological PJK (non-PJK patients, group II, 67.8%) at postoperative 2 years. PJK presented more prevalence in type III and type IV of LDK types (26/27, 96.3%). However, Roussouly types did not show any significant difference in PJK prevalence. In radiological parameters, a larger preoperative SVA (P = 0.018) and PI-LL (P = 0.015) were associated with PJK. Also, smaller quantity and lower quality of paraspinal muscles at T12-L1 level showed significant (P < 0.001) relationship with PJK. On multivariate logistic regression, higher LDK type (odds ratio [OR]: 2.11, 95% confidence interval [CI]: 1.24-3.56), smaller quantity (OR: 1.03, 95% CI: 1.00-1.07), and higher degree of paraspinal muscle degeneration (OR: 1.46, 95% CI: 0.92-2.31) were independent predictors of postoperative PJK. CONCLUSION: Although various factors are related to PJK following long segment fusion, preoperative conditions such as LDK types and degree of paraspinal muscle degeneration might be related to the development of PJK.Level of Evidence: 3.