Modified non-flared fully covered self-expandable metal stent for preoperative biliary drainage in pancreatic cancer.

BACKGROUND AND AIM: Durable biliary drainage is essential in patients with pancreatic cancer in the era of effective neoadjuvant chemotherapy (NACT). Plastic stent (PS) tends to occlude easily, and current metal stents are designed for nonresectable cancer. We evaluated the efficacy of a modified non-flared fully covered self-expandable metal stent (M-FCSEMS) during the perioperative period in patients with resectable or borderline resectable pancreatic cancer. METHODS: Consecutive patients with resectable or borderline resectable pancreatic ductal adenocarcinoma had a 12-mm M-FCSEMS (M-FCSEMS group) or 7-Fr PS (PS group) placed for biliary decompression before NACT or curative-intent surgery. The primary outcome was the re-intervention rate, and secondary outcomes were technical success, stent patency, and adverse events (AEs). RESULTS: Endoscopic stent placement was technically successful in all 60 patients. Twenty-three patients underwent surgery and 37 NACT before surgery. Re-intervention was performed in 10.0% (3/30) of patients in the M-FCSEMS group and 36.7% (11/30) of patients in the PS group (P = 0.030). The stent patency at 180 days was 89.8% (95% confidence interval, 77.3-100.0%) in the M-FCSEMS group and 30.2% (95% confidence interval, 11.4-80.0%) in the PS group (P < 0.0001). Stent-related AEs occurred in 10.0% (3/30) in the M-FCSEMS group and 40.0% (12/30) in the PS group (P = 0.015). Surgery-related AEs occurred in 10.5% (2/19) and 14.3% (3/21) in the M-FCSEMS and PS groups (P = 0.549). CONCLUSIONS: Modified non-flared fully covered self-expandable metal stents are effective and safe for durable biliary drainage in patients with resectable or borderline resectable pancreatic cancer during the perioperative period.

Topological Magnon Band Crossing in Y_{2}Ir_{2}O_{7}.

Topological magnonic materials have attracted much interest because of the potential for dissipationless spintronic applications. Pyrochlore iridates are theoretically regarded as good candidates for designing topological magnon bands. However, experimental identification of topological magnon bands in pyrochlore iridates remains elusive. We explored this possibility in Y_{2}Ir_{2}O_{7} using Raman spectroscopy to measure both the single-magnon excitations and anomalous phonon shifts. From the single-magnon energies and tight-binding model calculations concerning the phonons, we determined the key parameters in the spin Hamiltonian. These confirm that Y_{2}Ir_{2}O_{7} hosts a nontrivial magnon band topology distinct from other pyrochlore iridate compounds. Our work demonstrates that pyrochlore iridates constitute a system in which the magnon band topology can be tailored and that Raman spectroscopy is a powerful technique to explore magnon band topology.

Momentum-Dependent Magnon Lifetime in the Metallic Noncollinear Triangular Antiferromagnet CrB_{2}.

Noncollinear magnetic order arises for various reasons in several magnetic systems and exhibits interesting spin dynamics. Despite its ubiquitous presence, little is known of how magnons, otherwise stable quasiparticles, decay in these systems, particularly in metallic magnets. Using inelastic neutron scattering, we examine the magnetic excitation spectra in a metallic noncollinear antiferromagnet CrB_{2}, in which Cr atoms form a triangular lattice and display incommensurate magnetic order. Our data show intrinsic magnon damping and continuumlike excitations that cannot be explained by linear spin wave theory. The intrinsic magnon linewidth Γ(q,E_{q}) shows very unusual momentum dependence, which our analysis shows to originate from the combination of two-magnon decay and the Stoner continuum. By comparing the theoretical predictions with the experiments, we identify where in the momentum and energy space one of the two factors becomes more dominant. Our work constitutes a rare comprehensive study of the spin dynamics in metallic noncollinear antiferromagnets. It reveals, for the first time, definite experimental evidence of the higher-order effects in metallic antiferromagnets.

Magnetization Density Distribution of Sr_{2}IrO_{4}: Deviation from a Local j_{eff}=1/2 Picture.

5d iridium oxides are of huge interest due to the potential for new quantum states driven by strong spin-orbit coupling. The strontium iridate Sr_{2}IrO_{4} is particularly in the spotlight because of the so-called j_{eff}=1/2 state consisting of a quantum superposition of the three local t_{2g} orbitals with, in its simplest version, nearly equal populations, which stabilizes an unconventional Mott insulating state. Here, we report an anisotropic and aspherical magnetization density distribution measured by polarized neutron diffraction in a magnetic field up to 5 T at 4 K, which strongly deviates from a local j_{eff}=1/2 picture even when distortion-induced deviations from the equal weights of the orbital populations are taken into account. Once reconstructed by the maximum entropy method and multipole expansion model refinement, the magnetization density shows four cross-shaped positive lobes along the crystallographic tetragonal axes with a large spatial extent, showing that the xy orbital contribution is dominant. The analogy to the superconducting copper oxide systems might then be weaker than commonly thought.

Macrovascular invasion is not an absolute contraindication for living donor liver transplantation.

The indication of liver transplantation (LT) for the treatment of advanced hepatocellular carcinoma (HCC) is expanding. However, portal vein tumor thrombus (PVTT) has been still accepted as an absolute contraindication. We experienced an unexpectedly good prognosis in selected patients. Therefore, we tried to identify the prognostic factors after LT for HCC with major PVTT. Among 282 patients who underwent living donor liver transplantation (LDLT) for HCC from January 2009 to December 2013, 11 (3.9%) patients with major PVTT that was preoperatively diagnosed were investigated. The 1-, 3-, and 5-year recurrence-free survival rates were 63.6%, 45.5%, and 45.5%, respectively, and all recurrent cases showed intrahepatic and extrahepatic recurrence. The 1-, 3-, and 5-year overall survival rates were 72.7%, 63.6%, and 63.6%, respectively, and 2 patients with delayed recurrence survived approximately 5 years after LT. Main portal vein (PV) invasion (P < 0.01), high alpha-fetoprotein × protein induced by vitamin K absence/antagonist-II (AP) score (≥20,000; P < 0.01), high standardized uptake value (SUV) ratio (tumor/background liver) in positron emission tomography (≥2.1; P < 0.01), and a large original tumor (≥7 cm; P = 0.03) were significant risk factors for recurrence. In conclusion, if the PVTT has not expanded to the main PV and the AP score is not high, we can consider LDLT as a curative treatment option. Liver Transplantation 23:19-27 2017 AASLD.

Spherical Process Models for Global Spatial Statistics.

Statistical models used in geophysical, environmental, and climate science applications must reflect the curvature of the spatial domain in global data. Over the past few decades, statisticians have developed covariance models that capture the spatial and temporal behavior of these global data sets. Though the geodesic distance is the most natural metric for measuring distance on the surface of a sphere, mathematical limitations have compelled statisticians to use the chordal distance to compute the covariance matrix in many applications instead, which may cause physically unrealistic distortions. Therefore, covariance functions directly defined on a sphere using the geodesic distance are needed. We discuss the issues that arise when dealing with spherical data sets on a global scale and provide references to recent literature. We review the current approaches to building process models on spheres, including the differential operator, the stochastic partial differential equation, the kernel convolution, and the deformation approaches. We illustrate realizations obtained from Gaussian processes with different covariance structures and the use of isotropic and nonstationary covariance models through deformations and geographical indicators for global surface temperature data. To assess the suitability of each method, we compare their log-likelihood values and prediction scores, and we end with a discussion of related research problems.

What is the best immunosuppressant combination in terms of antitumor effect in hepatocellular carcinoma?

AIM: Despite its known anticancer benefits, monotherapy with sirolimus is not sufficient to achieve optimal immunosuppression to prevent rejection. However, there is no published prospective study to compare the anticancer effect between various immunosuppressive combinations. Therefore, we analyzed the anticancer effects of various immunosuppressive regimens in order to provide experimental evidence for selecting an optimal immunosuppressive regimen after liver transplantation for hepatocellular carcinoma (HCC). METHODS: The Huh7 cell line was used as a model for HCC in both in vitro and in vivo mouse experiments. The immunosuppressant regimens tested were: tacrolimus, sirolimus, MMF, sirolimus plus tacrolimus, and sirolimus plus MMF. 3-(4 5-Dimethylthiazol-2-yl)-2 5-diphenyltetrazolium bromide assays showed that the sirolimus plus MMF combination appeared to be synergistic in its cell suppressive effects, achieving statistically significant lowest cell viability. RESULTS: In vitro western blot analysis showed that there were lower levels of expression of phosphorylated mammalian target of rapamycin, p70S6K and p4EBP1, transforming growth factor-ß and pSmad3 expression in the cells treated with sirolimus, MMF and sirolimus plus MMF. Finally, in the mouse model of tumorigenesis, the sirolimus plus MMF and sirolimus plus tacrolimus showed the most suppressive effect in terms of tumor volume. CONCLUSION: Throughout both the in vitro and in vivo experiments, the sirolimus and MMF combination had the most consistent and greatest antiproliferative effects.

Risk Factors for the Adverse Events after Conversion from Twice-Daily to Once-Daily Tacrolimus in Stable Liver Transplantation Patients.

Despite the therapeutic equivalence between twice-daily and once-daily tacrolimus, patient safety after conversion is still a concern. We reviewed 218 liver transplantation (LT) patients who converted twice-daily to once-daily tacrolimus between May 2011 and January 2014. Thirty (13.8%) patients had adverse events after conversion, with a liver function test (LFT) abnormality being the most common adverse event (n = 17). Despite the decrease in serum tacrolimus of > 30% after conversion, none of the patients who were converted to a dosage ratio (once-daily tacrolimus dosage: twice-daily tacrolimus dosage) > 1 had an LFT abnormality. Most patients with an LFT abnormality improved after increasing the once-daily tacrolimus dosage (n = 2), returned to a previous medication, and/or added another immunosuppressant (n = 15). One patient had acute cellular rejection, which improved after steroid pulse treatment, and another patient had graft failure. In patients with a dosage ratio ≤ 1, the conversion time within 5 years after LT was the only significant risk factor for an LFT abnormality after conversion (odds ratio: 11.850, 95% confidence interval: 1.321-106.325, P = 0.027). In conclusion, the dosage ratio and time after LT should be carefully considered during conversion from twice-daily to once-daily tacrolimus.

Response-Guided Therapy for Hepatitis C Virus Recurrence Based on Early Protocol Biopsy after Liver Transplantation.

Hepatitis C virus (HCV) recurrence after liver transplantation (LT) is universal and progressive. Here, we report recent results of response-guided therapy for HCV recurrence based on early protocol biopsy after LT. We reviewed patients who underwent LT for HCV related liver disease between 2010 and 2012. Protocol biopsies were performed at 3, 6, and 12 months after LT in HCV recurrence (positive HCV-RNA). For any degree of fibrosis, ≥ moderate inflammation on histology or HCV hepatitis accompanying with abnormal liver function, we treated with pegylated interferon and ribavirin. We adjusted treatment period according to individual response to treatment. Among 41 HCV related recipients, 25 (61.0%) who underwent protocol biopsies more than once were enrolled in this study. The mean follow-up time was 43.1 (range, 23-55) months after LT. Genotype 1 and 2 showed in 56.0% and 36.0% patients, respectively. Of the 25 patients, 20 (80.0%) started HCV treatment after LT. Rapid or early virological response was observed in 20 (100%) patients. Fifteen (75.0%) patients finished the treatment with end-of-treatment response. Sustained virological response (SVR) was in 11 (55.0%) patients, including 5 (41.7%) of 12 genotype 1 and 6 (75.0%) of 8 non-genotype 1 (P = 0.197). Only rapid or complete early virological response was a significant predictor for HCV treatment response after LT (100% in SVR group vs. 55.6% in non-SVR group, P = 0.026). Overall 3-yr survival rate was 100%. In conclusion, response-guided therapy for HCV recurrence based on early protocol biopsy after LT shows encouraging results.

Temperature-dependent interplay of Dzyaloshinskii-Moriya interaction and single-ion anisotropy in multiferroic BiFeO3.

Low-energy magnon excitations in multiferroic BiFeO3 were measured in detail as a function of temperature around several Brillouin zone centers by inelastic neutron scattering experiments on single crystals. Unique features around 1 meV are directly associated with the interplay of the Dzyaloshinskii-Moriya interaction and a small single-ion anisotropy. The temperature dependence of these and the exchange interactions were determined by fitting the measured magnon dispersion with spin-wave calculations. The spectra best fit an easy-axis type magnetic anisotropy and the deduced exchange and anisotropy parameters enable us to determine the anharmonicity of the magnetic cycloid. We then draw a direct connection between the changes in the parameters of spin Hamiltonian with temperature and the physical properties and structural deformations of BiFeO3.

Synthesis of novel poly(amidoxime) grafted multiwall carbon nanotube gel and uranium adsorption.

This is the first report on the synthesis of a new functional nanocomposite gel containing amidoxime functionalized multiwall carbon nanotube (AO-MWNT-FNC GEL). The surface morphology of AO-MWNT-FNC GEL was investigated by field emission scanning electron microscopy. The modification of gel with amidoxine groups was confirmed by Fourier transform infra red spectroscopy. The AO-MWNT-FNC GEL provides effective binding with uranium ions as was ascertained by X-ray photoelectron spectroscopy. The AO-MWNT-FNC GEL was utilized as the new adsorbent for the recovery of uranium ions from aqueous solution. UV-visible spectroscopy was used to monitor the adsorption capacity of the AO-MWNT-FNC GEL toward uranium ions. The influence of initial uranium ion concentration and solution pH on the adsorption capacity of the AO-MWNT-FNC GEL were studied in batch experiments. The new FNC-GEL designed in this study is distinguished by higher adsorption capacity for uranium ions due to the synergistic contributions from high surface area of MWNT and the functional AO groups in FNC-GEL and exhibits potential for efficient recovery of uranium ions.

The protective effect of Kaempferia parviflora extract on UVB-induced skin photoaging in hairless mice.

BACKGROUND: Chronic skin exposure to ultraviolet (UV) light increases reactive oxygen species (ROS) and stimulates the expression of matrix metalloproteinases (MMPs) through c-Jun and c-Fos activation. These signaling cascades induce the degradation of extracellular matrix (ECM) components, resulting in photoaging. METHODS: This study evaluated the preventive effect of the ethanol extract of Kaempferia parviflora Wall. ex. Baker (black ginger) on UVB-induced photoaging in vivo. To investigate the antiphotoaging effect of K. parviflora extract (KPE), UVB-irradiated hairless mice administered oral doses of KPE (100 or 200 mg/kg/day) for 13 weeks. RESULTS: In comparison to the UVB control group, KPE significantly prevented wrinkle formation and the loss of collagen fibers with increased type I, III, and VII collagen genes (COL1A1, COL3A1, and COL7A1). The decrease in wrinkle formation was associated with a significant reduction in the UVB-induced expression of MMP-2, MMP-3, MMP-9, and MMP-13 via the suppression of c-Jun and c-Fos activity. KPE also increased the expression of catalase, which acts as an antioxidant enzyme in skin. In addition, expression of inflammatory mediators, such as nuclear factor kappa B (NF-κB), interleukin-1ß (IL-1ß), and cyclooxygenase-2 (COX-2), was significantly reduced by KPE treatment. CONCLUSION: The results show that oral administration of KPE significantly prevents UVB-induced photoaging in hairless mice, suggesting its potential as a natural antiphotoaging material.

Magnon breakdown in a two dimensional triangular lattice Heisenberg antiferromagnet of multiferroic LuMnO3.

The breakdown of magnons, the quasiparticles of magnetic systems, has rarely been seen. By using an inelastic neutron scattering technique, we report the observation of spontaneous magnon decay in multiferroic LuMnO3, a simple two dimensional Heisenberg triangular lattice antiferromagnet, with large spin S=2. The origin of this rare phenomenon lies in the nonvanishing cubic interaction between magnons in the spin Hamiltonian arising from the noncollinear 120° spin structure. We observed all three key features of the nonlinear effects as theoretically predicted: a rotonlike minimum, a flat mode, and a linewidth broadening, in our inelastic neutron scattering measurements of single crystal LuMnO3. Our results show that quasiparticles in a system hitherto thought of as "classical" can indeed break down.

The effect of donor against recipient one-way HLA mismatch on liver transplantation outcomes from a multicenter registry analysis.

Donor against recipient one-way Human leukocyte antigen (HLA) mismatch (D → R one-way HLA MM) seemed strongly associated with graft-versus-host disease (GVHD). The aim of this study is to investigate the relevance of D → R one-way HLA MM in outcome of liver transplantation (LT). We retrospectively analyzed 2670 patients in Korean Organ Transplantation Registry database between April 2014 and December 2020. The patients were categorized into two groups whether D → R one-way HLA MM or not and evaluated the outcomes of LT between the two groups. 18 patients were found to be D → R one-way HLA MM. The incidence of GVHD (0.3% vs. 22.2%, p < 0.001) and mortality rate (11.6% vs. 38.9%, p = 0.003) was much higher in D → R one-way HLA MM group. D → R one-way HLA MM at 3 loci was seemed to be strongly associated with the incidence of GVHD (OR 163.3, p < 0.001), and found to be the strongest risk factor for patient death (HR 12.75, p < 0.001). Patients with D → R one-way HLA MM at 3 loci showed significantly lower overall survival (p < 0.001) but there were no significant differences in rejection-free survival and death-censored graft survival. D → R one-way HLA MM at 3 loci not only affects the overall survival of LT patients but also the incidence of GVHD.

Physical Performance Decline During the Early Posttransplantation Period Affects Survival After Living Donor Liver Transplantation.

BACKGROUND: Patient physical performance has been emphasized in liver transplant recipients; however, evidence for living donor liver transplantation (LDLT) patients is lacking. This study investigated the impact of physical performance decline during the early posttransplantation period on survival and risk factors for this decline in LDLT recipients. METHODS: From national registry data, 2703 LDLT patients were divided into 2 groups based on the change in their Karnofsky performance status (KPS) between 1 and 6 mo posttransplantation: declined KPS (n = 188) and control (n = 2515). Multivariable analyses were conducted to control for confounders, including posttransplantation complications. RESULTS: Estimated 5-y patient survival rates were 91.6% in the declined KPS group and 96.3% in the control group, favoring the latter ( P = 0.003). The survival hazard of KPS decline was significant in a baseline covariates-adjusted Cox model (hazard ratio [HR], 2.60; 95% confidence interval [CI], 1.37-4.95) and an adjusted model accounting for posttransplantation complications (HR, 3.38; 95% CI, 1.70-6.72). In subgroup analyses, KPS decline independently reduced survival in patients without complications (HR, 3.95; 95% CI, 1.67-9.34), and the trend was similar in patients with complications, although significance was marginal (HR, 3.02; 95% CI, 0.98-9.27). We found that only posttransplantation complications, such as rejection, infection, bile duct complication, and vascular complication, were significant risk factors for KPS decline after LDLT. CONCLUSIONS: Physical performance decline during the early posttransplantation period independently reduced survival rates, and posttransplantation complications were the only significant risk factors for physical performance decline in LDLT recipients.

Spin wave measurements over the full Brillouin zone of multiferroic BiFeO3.

Using the inelastic neutron scattering technique, we measured the spin wave dispersion over the entire Brillouin zone of room temperature multiferroic BiFeO(3) single crystals with magnetic excitations extending to as high as 72.5 meV. The full spin waves can be explained by a simple Heisenberg Hamiltonian with a nearest-neighbor exchange interaction (J=4.38 meV), a next-nearest-neighbor exchange interaction (J'=0.15 meV), and a Dzyaloshinskii-Moriya-like term (D=0.107 meV). This simple Hamiltonian determined, for the first time, for BiFeO(3) provides a fundamental ingredient for understanding the novel magnetic properties of BiFeO(3).

Investigating the spatio-temporal variation of hepatitis A in Korea using a Bayesian model.

Hepatitis A is a water-borne infectious disease that frequently occurs in unsanitary environments. However, paradoxically, those who have spent their infancy in a sanitary environment are more susceptible to hepatitis A because they do not have the opportunity to acquire natural immunity. In Korea, hepatitis A is prevalent because of the distribution of uncooked seafood, especially during hot and humid summers. In general, the transmission of hepatitis A is known to be dynamically affected by socioeconomic, environmental, and weather-related factors and is heterogeneous in time and space. In this study, we aimed to investigate the spatio-temporal variation of hepatitis A and the effects of socioeconomic and weather-related factors in Korea using a flexible spatio-temporal model. We propose a Bayesian Poisson regression model coupled with spatio-temporal variability to estimate the effects of risk factors. We used weekly hepatitis A incidence data across 250 districts in Korea from 2016 to 2019. We found spatial and temporal autocorrelations of hepatitis A indicating that the spatial distribution of hepatitis A varied dynamically over time. From the estimation results, we noticed that the districts with large proportions of males and foreigners correspond to higher incidences. The average temperature was positively correlated with the incidence, which is in agreement with other studies showing that the incidences in Korea are noticeable in spring and summer due to the increased outdoor activity and intake of stale seafood. To the best of our knowledge, this study is the first to suggest a spatio-temporal model for hepatitis A across the entirety of Korean. The proposed model could be useful for predicting, preventing, and controlling the spread of hepatitis A.

Differences in Bile Microbiology and Antibiotic Resistances between Liver Transplant Recipients and Non-Transplant Patients.

Background: Treatment of biliary infection in liver transplant (LT) recipients is a challenge, especially because of ineffectiveness of the antibiotic agents otherwise recommended for non-transplant populations. We aimed to understand the factors underlying the choice of antibiotic therapy. Patients and Methods: A total of 373 bile cultures from LT recipients with biliary complications (n = 127; LT group) and from a non-transplant population that underwent cholecystectomy for acute cholecystitis (n = 246; non-transplant group) between January 2009 and December 2018, were investigated. Results: Polymicrobial cultures (13.4% vs. 1.6%; p < 0.001), Enterococcus faecium (26.0% vs. 8.5%; p < 0.001), and Pseudomonas (13.4% vs. 4.1%; p = 0.001) in the LT group, and non-faecium enterococci (3.9% vs. 18.3%; p < 0.001) and Enterobacteriales (40.2% vs. 54.9%; p = 0.007), especially Escherichia (11.0% vs. 29.7%; p < 0.001), in the non-transplant group, showed higher abundance. Most of the antibiotic agents recommended as initial antibiotic therapy for the non-transplant population as per previous guidelines were not effective in LT recipients. The incidences of Enterococcus faecium (14.9% vs. 32.5%; p = 0.029) in the LT recipients with model for end-stage liver disease (MELD) score >12 and non-faecium enterococci (8.5% vs. 1.3%; p = 0.042) in those with MELD score ≤12 were higher than those in the other group. The incidence of Enterobacteriales increased over time after LT (p = 0.048) and was similar to that in the non-transplant group after one year of LT. Bile micro-organisms in LT recipients, resistant to most antibiotic agents, especially soon after LT changed over time and became similar to those in the non-transplant group after one year of LT. Conclusions: Antibiotic therapy for biliary infection in LT recipients should be different from that in non-transplant populations, considering clinical factors such as the time interval after LT and MELD score.

Antiferromagnetic Kitaev interaction inJeff=1/2 cobalt honeycomb materials Na3Co2SbO6and Na2Co2TeO6.

Finding new materials with antiferromagnetic (AFM) Kitaev interaction is an urgent issue for quantum magnetism research. We conclude that Na3Co2SbO6and Na2Co2TeO6are new honeycomb cobalt-based systems with AFM Kitaev interaction by carrying out inelastic neutron scattering experiments and subsequent analysis. The spin-orbit excitons observed at 20-28 meV in both compounds strongly support the idea that Co2+ions of both compounds have a spin-orbital entangledJeff= 1/2 state. Furthermore, we found that a generalized Kitaev-Heisenberg Hamiltonian can describe the spin-wave excitations of both compounds with additional 3rd nearest-neighbor interaction. Our best-fit parameters show significant AFM Kitaev terms and off-diagonal symmetric anisotropy terms of a similar magnitude in both compounds. We also found a strong magnon-damping effect at the higher energy part of the spin waves, entirely consistent with observations in other Kitaev magnets. Our work suggests Na3Co2SbO6and Na2Co2TeO6as rare examples of the AFM Kitaev magnets based on the systematic studies of the spin waves and analysis.

Spin texture induced by non-magnetic doping and spin dynamics in 2D triangular lattice antiferromagnet h-Y(Mn,Al)O3.

Novel effects induced by nonmagnetic impurities in frustrated magnets and quantum spin liquid represent a highly nontrivial and interesting problem. A theoretical proposal of extended modulated spin structures induced by doping of such magnets, distinct from the well-known skyrmions has attracted significant interest. Here, we demonstrate that nonmagnetic impurities can produce such extended spin structures in h-YMnO3, a triangular antiferromagnet with noncollinear magnetic order. Using inelastic neutron scattering (INS), we measured the full dynamical structure factor in Al-doped h-YMnO3 and confirmed the presence of magnon damping with a clear momentum dependence. Our theoretical calculations can reproduce the key features of the INS data, supporting the formation of the proposed spin textures. As such, our study provides the first experimental confirmation of the impurity-induced spin textures. It offers new insights and understanding of the impurity effects in a broad class of noncollinear magnetic systems.