Specimen Size Research Articles

Investigation of fracture performance of asphalt mixtures considering size effect law and equivalent crack propagation law

The integration of the Size Effect Law (SEL) and the equivalent Linear Elastic Fracture Mechanics (LEFM) in characterizing the fracture behavior of asphalt mixtures has received limited attention. This study presents a preliminary exploration into the application of equivalent LEFM on the fracture characteristics of two asphalt mixtures, AC10 and AC16, accounting for variations in specimen size. Semi-circular Bending (SCB) tests were conducted on specimens with four different diameters (D = 76 mm, 100 mm, 125 mm, and 150 mm) and three notch-to-radius ratios (α = 0.2, 0.4, and 0.6) at a temperature of −10 °C. The equivalent crack propagation (ECP) length, crack growth resistance, and the size of the Fracture Process Zone (FPZ) were determined and subjected to analysis. The findings revealed a size effect on the ECP length, crack growth resistance, and FPZ size, with an increase in specimen size leading to a corresponding increase in these parameters. Conversely, an increase in α resulted in a decrease in all three types of data. A power law relationship was established between the ECP length and crack growth resistance. It was observed that AC16 demonstrated superior fracture resistance compared to AC10, particularly in terms of crack growth resistance. The initial notch length, ECP length, and FPZ size were found to be of the same order of magnitude, suggesting that the equivalent LEFM can produce more accurate fracture results under low temperatures than the traditional LEFM.

3D Printed Stent from Graphene-Polyethylene Glycol Diacrylate Using Digital Light Processing Technique

Abstract This paper presents the development of the photocurable resin material based on the graphene reinforced polyethylene glycol diacrylate (gPEGDA) for vascular stent fabrication using a commercial 3D printer. 3D printing with digital light processing (DLP) technique is an attractive alternative for low-cost fast fabrication with high accuracy. Four photocurable resin compositions were prepared by mixing PEGDA and varied composition of graphene and the photoinitiator according to the design of experiment of 22 full factorial design. The diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO) photoinitiator was adopted to meet the required 405 nm UV-light source wavelength of the 3D printer for stent fabrication. Material characterization of the UV-absorbance and viscosity tests were conducted and optimized to obtain resin printability. Mechanical characteristics tests were conducted to obtain the best resin composition for stent application. For this purpose, the tensile tests were conducted according to the ASTM D638 standard using the type-V specimen size. The test specimens were 3D printed with varied UV exposure time 20 and 30 seconds. Finally, the stents were successfully fabricated using a commercial 3D printer DLP with the bottom parameter time setting of 60 seconds, and the UV exposure time of 30 seconds. The resin material was applicable for 3D printing of the stent. The result has shown that 3D printer with DLP technique is suitable for stent fabrication with excellent surface quality. Moreover, the innovative bioresorbable stent materials and fabrication approach could open up new possibilities in the development of medical devices, particularly in the treatment of vascular diseases.

Paediatric oral and maxillofacial biopsies: A retrospective institutional archival study.

This is a retrospective cross-sectional study of oral and maxillofacial biopsies in paediatric population, up to 16 years of age from 1991 to 2021. This study aimed to investigate the frequency, demographic and clinicopathological characteristics of paediatric biopsies according to the diagnosis categories of the main tertiary centre in Malaysia. A total of 17294 histopathological reports from Diagnostic Oral Pathology Unit between 1991 and 2021 were retrieved. One thousand eleven histopathological reports that fulfilled the inclusion and exclusion criteria were included. Information of interest was extracted from histopathological reports. The lesions were categorised into 10 diagnosis categories. Descriptive and correlation analysis were performed. Paediatric oral and maxillofacial biopsies accounted for 5.9% of the total biopsies received. The peak incidence of diagnosis was in age range of 12 to 16 years old and mean age of 11.6 years old (±3.5), with female preponderance. The most common category of diagnosis was salivary gland pathology with mucocele (30%) being the most frequently diagnosed lesions. Lip and labial mucosa were the commonest site of occurrence. Specimen sizes smaller than 1 cm were the most common specimen diameter with mean size of 1.6 cm (±1.5). Age, site of occurrence and specimen size were statistically significant (P < 0.05) with paediatric oral and maxillofacial biopsies. This is a large-scale study of paediatric oral and maxillofacial biopsies of a tertiary centre over three decades. We hope this data is useful for chairside assessment and aids in diagnosis making.

Safety and efficacy of endoscopic submucosal dissection with gel immersion technique for superficial esophageal neoplasms.

Gel immersion (GI) endoscopy provides a good visual field in endoscopic submucosal dissection (ESD); however, its clinical outcomes are poorly understood. This study aimed to compare the treatment outcomes between esophageal gel immersion endoscopic submucosal dissection (GI-ESD) and conventional ESD (C-ESD) to determine the safety and efficacy of GI-ESD. The data of 71 consecutive patients who underwent esophageal ESD between April 2021 and March 2023 at a Japanese tertiary center were retrospectively reviewed. GI was achieved using an additional irrigation tube. The treatment outcomes between the GI-ESD and C-ESD groups were compared using inverse probability of treatment weighting (IPTW) to control for confounding factors. A total of 75 superficial esophageal epithelial neoplasms (41 in the C-ESD and 34 in the GI-ESD groups) were treated using ESD. The mean procedure time in the GI-ESD group was significantly shorter than that in the C-ESD group (59.2±36.2 vs 85.3±45.7min, P=0.008). After IPTW adjustment, the mean procedural times were 62.6±36.6 and 82.9±41.7min in the GI-ESD and C-ESD groups, respectively (P=0.037), and the incidence rate of muscle layer damage was 4.2% in the GI-ESD group and 30.6% in the C-ESD group (P=0.001). In the multivariate analysis, specimen size ≥30mm (odds ratio [OR]: 9.44, 95% confidence interval [CI]: 2.46-36.30, P=0.001) was positively correlated with longer procedural time (≥90min), whereas GI-ESD (OR: 0.19, 95%CI: 0.05-0.68, P=0.011) showed a negative association. Esophageal GI-ESD may be useful in terms of safety and time efficiency. The GI technique could be an option for esophageal ESD.

Size effect of typical hygrothermal properties test values for building insulation materials

Thermal and moisture properties of building insulation materials are crucial input parameters for analyzing thermal and moisture transfer phenomena in building environments. Accurate determination of these parameters under different conditions is essential for the correct application and assessment of materials and envelope structures. However, numerous factors influence thermal and moisture properties, and while extensive research has been conducted on this topic, the effects of specimen size on typical thermal and moisture property test values remain unclear. To address the issue of unreliable data caused by random specimen sizes in thermal and moisture property testing of building insulation materials, this study selects three materials—expanded polystyrene (EPS), extruded polystyrene (XPS), and foamed cement—as test subjects to explore the size effects on typical thermal and moisture property test values. The results indicate that specimen size significantly affects the test values for typical thermal and moisture properties, with only a few experiments showing negligible size effects for certain materials. For foamed cement, recommended specimen sizes for thermal conductivity testing using the guarded hot plate method and the transient plane source method are 300 × 300 × 30 mm and 50 × 50 × 30 mm, respectively. Except for equilibrium moisture absorption experiments, the weight of other moisture property tests is generally represented by thickness > planar dimensions.

Retrospective analysis in in situ ductal carcinoma; 11 years of experience

Objective: To describe our experience in the diagnosis, treatment and follow up of patients with ductal carcinoma in situ (DCIS). Materials and methods: 953 breast carcinomas treated in the Mastology service of the Department of Gynecology and Obstetrics of the Hospital Aleman of Buenos Aires, between January 2004 and December 2014, are retrospectively analyzed. 206 biopsies (BRQ 25-mammotome 151-core biopsy 30) of ductal carcinomas in situ were identified, resulting after definitive pathological evaluation in 172 (18%) pure ductal carcinomas in situ of the total of 953 patients analyzed. Results: 206 biopsies (BRQ 25-mammotome 151-core biopsy 30) of ductal carcinomas in situ were identified, resulting after definitive pathological evaluation in 172 (18%) pure ductal carcinomas in situ of the total of 953 patients analyzed. The imaging report in the total of the 206 patients showed microcalcifications in 80.1%. The diagnosis of carcinoma in situ was made in 181 (87%) patients by preoperative microinvasive procedures and in the remaining 25 (13%) patients by radiosurgical biopsy (BRQ). There was evidence of 18.8% underdiagnosis after microinvasive procedures. In our case series, 84.3% were GH3/GH2 while 15.7% were GH 1. When comparing the size of the surgical specimens and correlating it with the 34 cases of invasive and microinvasive carcinoma, it showed that 54.8% of invasion in those tumors greater than 30 mm, 50.4% in those that exceeded 21 mm and in no case in those less than 10 mm. 20% of multicentric lesions were associated with invasive tumor. Sentinel lymph node technique was performed in 23.8% patients in the first surgery, resulting negative in all cases. When evaluating radiation and hormonal treatment, radiotherapy was performed in 131 patients (85.6%) and hormonal treatment was performed in 75% of the patients. In the follow-up until December 2014, 11 relapses (5.23%) were recorded. Conclusion: Our results are consistent with the international indexed literature in reference to diagnosis, treatment and recurrence rate pure of DCIS.

Characterization of 3D printed composite for final dental restorations.

This study evaluated the mechanical, optical, microstructural, surface, and adhesive behavior of a 3D printing resin comparing it with a machinable resin composite. Specimens of different sizes and shapes were either printed (Vitality, Smart Dent) or machinable (Grandio Blocs, Voco GmbH) resin composites with similar composition were prepared. Surface and mechanical characterization were performed with Knoop hardness, flexural strength (three-point-bending), and elastic modulus tests. The wear of the tested materials was evaluated against steatite antagonists. The optical properties stability (color change, ΔE00, and translucency, TP00) were observed after staining in red wine. In addition, the bond strength of the resin composites to two resin cement protocols were investigated with microshear bond strength tests at baseline and after thermocycling. Scanning electron microscope (SEM) coupled with Energy-Dispersive X-ray Spectroscopy (EDS) was used for microstructural and chemical characterization. Statistical analyses were performed with t- and ANOVA tests. Hardness values (132.76 (16.32) KH- Machinable and 35.87 (2.78) KH - Printed), flexural strength (172.17 (26.99) MPa - Machinable and 88.69 (8.39) MPa - Printed), color and translucency change (1.86 (0.31)/0.06 - Machinable and 3.73 (0.36)/9,16- Printed), and wear depth (24.97mm (3.60)- Machinable and 7.16mm (2.84) - Printed) were statistically different. Average Regarding bond strength, mean values (MPa) for non-aged and aged groups were respectively 21.76 (6.64) / 31.9 (12.66) for Bifix cement (Voco GmbH, Cuxhaven, Germany) and 26.75 (5.14) / 24.36 (6.85) for Variolink cement (Ivoclar Vivadent, Schaan, Liechtenstein) in Printed and 17.79 (3.89) / 9.01 (3.36) ) for Bifix cement and 22.09 (6.55) / 11.01 (3.77) for Variolink cement in Machinable materials. The material and aging factors did affect bond strength but the cement factor did not (p = 0.202). No statistical differences were observed for mean roughness (Ra) between materials. The better dispersion and larger size of the inorganic particles in the Machinable resin were contrasted with the clustered smaller particles of printed resin, under SEM. The mechanical properties and color stability of the machinable resin were superior to those of the printed resin, probably due to the greater amount and dispersion of inorganic particles in the Mach resin, but bond strength after aging was stronger and more stable in the printed resin. 3D-printed resin composites with similar compositions to machinable resin composites do not necessarily exhibit the same properties, which can impact clinical performance. Understanding these differences can assist manufacturers in improving their materials and help clinicians distinguish between materials appropriate for provisional and final restorations.

Assessment of the impact behavior of CLF-1 steel with Charpy V-notch testing and miniature Charpy V-notch testing

China Low-activation Ferrite steel (CLF-1), as one of the structural materials developed in China for fusion reactors, is a Reduced activation Ferritic/Martensitic (RAFM) steel modeled after the traditional T91 steel (9Cr-1Mo-0.2V-0.08Nb). For fusion reactor materials, the Charpy impact testing is an important method to assess their notch sensitivity. In this study, Charpy impact tests were conducted on CLF-1 steel using Charpy V-notch specimens (CVN) and Miniature Charpy V-notch specimens (Kleinstprobe, KLST) to assess the impact behavior of CLF-1 steel, and data normalization was performed on the KLST specimen. The results show that as the specimen size of CLF-1 steel decreased, the curves of impact absorbed energy, lateral expansion, and shear fracture appearance shifted towards lower temperatures, and the impact absorbed energy significantly decreased. Both the macroscopic and microscopic characteristics of the specimens obtained from the experiments indicated that KLST specimens could achieve the same fracture characteristics as CVN specimens. Additionally, at the same experimental temperature, KLST specimens exhibited a higher proportion of ductile fracture regions.

Efficacy and Safety of Single Clip Traction Assisted Endoscopic Submucosal Dissection for Colonic Neoplasms: A Propensity Score Matching Analysis.

Endoscopic submucosal dissection (ESD) for colonic neoplasms is a technically intricate procedure. Internal traction using a single clip has emerged as a promising supportive technique for colonic ESD. Therefore, this study aimed to comprehensively evaluate and compare the efficacy and safety of ESD with and without the aid of single-clip traction. This retrospective study encompassed 36 patients who underwent single clip traction-assisted colonic ESD and 66 who underwent the traditional method of colonic ESD at Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University. We employed the propensity score-matching method to mitigate disparities in resected specimen size and tumor location. Post-matching, we comprehensively assessed treatment outcomes and incidence of adverse events between the two treatment groups (single clip traction-assisted ESD (scESD) and conventional ESD (cESD)). After propensity score matching, we observed 34 matched pairs. There were no significant differences between the two treatment groups regarding the en bloc resection rate, complete resection rate, and curative rate. However, the procedure duration was significantly shorter in the single clip traction-assisted ESD group compared to the conventional ESD group (20.00 [Interquatile Range (IQR)] (16.00-32.50) minutes vs 31.50 [IQR] (17.00-54.00) minutes, p = 0.0474). Furthermore, there was a significant increase in dissection speed in the single clip traction-assisted ESD group compared to the conventional ESD group (0.29 [IQR] (0.20-0.45) mm2/min vs 0.19 [IQR] (0.11-0.35) mm2/min, p = 0.0015). All lesions were resected in a single piece. Among the propensity-score-matched patients, only those treated with single clip traction-assisted ESD exhibited faster dissection speeds (p = 0.015). Furthermore, there were no substantial differences in adverse events such as intraoperative perforation, delayed perforation, or delayed bleeding. Our findings suggest that single clip traction-assisted colonic ESD is preferable to traditional colonic ESD, owing to its shorter procedure duration and faster dissection speed.

Helicobacter pylori infection increases risk of bleeding during endoscopic submucosal dissection for early gastric cancer.

Endoscopic submucosal dissection (ESD) is commonly used to treat early gastric cancer (EGC). The effects of Helicobacter pylori (HP) infection on ESD and the potential benefits of preoperative eradication of HP remain unclear. The study aims to evaluate the impact of HP infection on bleeding and lesion detection during ESD in patients with EGC. We retrospectively analyzed 634 consecutive patients who underwent ESD for EGC at our center between January 2018 and January 2023. Logistic regression was used to assess the impact of HP infection status on intraoperative bleeding and lesion detection rates. We developed a predictive model based on selected indicators and evaluated its performance using the ROC curve. HP-positive patients experienced a higher rate of intraoperative bleeding (28.8%) compared with HP-negative patients (8.9%) (P < 0.001). HP-positive patients also had longer procedure time (median: 58.5 vs. 50.0min, P < 0.001) and postoperative hospital stays (median: 4.35 vs. 4.07days, P = 0.036). Multivariate analysis identified HP-positive (OR = 4.84), multiple lesions (OR = 1.81), specimen size > 40mm (OR = 3.67), and submucosal invasion (OR = 2.27) as independent risk factors for intraoperative bleeding. The predictive model achieved an AUC of 0.807 (95%CI 0.761-0.852), with a sensitivity of 72.1% and specificity of 75.9%. Preoperative HP eradication was associated with an increased rate of lesion detection (OR = 2.82). Eradicating HP before ESD in patients with EGC reduces intraoperative bleeding and improves lesion detection. Preoperative HP eradication is therefore recommended in patients with EGC.

The effect of specimen size on the unconfined compressive strength of cement-stabilized granular mixtures made of natural and recycled aggregates

The cement-stabilization technique is employed on natural and recycled granular materials to improve their mechanical properties. The strength of these materials is assessed by the unconfined compressive strength on laboratory compacted specimens, typically after 7 days of curing. Standards and technical specifications specify different values of specimen height and diameter and different loading modes of testing. This makes the comparison between different materials and with the acceptance limits of technical specifications difficult. The research investigates the effect of specimen size and loading mode on the unconfined compressive strength of both natural and recycled cement-stabilized granular materials. The results revealed significant differences in strength due to variations in specimen size and loading mode. As expected, an increase in specimen slenderness resulted in a decrease in compressive strength. A linear regression model was developed to quantify the effect of the experimental variables on the compressive strength of the two cement-stabilized materials.

Efficient sealing of cemented sheath: An oil-responsive self-healing latex with toughness enhancement for cement composites

The integrity of the cemented sheath is important to the safe exploration of oil and gas resources. Sealing failure of cement sheath will result in formation fluid channeling and pressure carryover in the annulus. The both toughening and oil-responsive self-healing latex (TOS) was prepared to achieve efficient sealing of cemented sheath, and prolong its service life. The structure and oil swelling behavior of TOS, its toughening and self-healing effects on hardened cement paste (HCP) were analyzed by comprehensive characterizations. Results demonstrated that TOS possessed excellent stability and an oil swelling rate of 1235 %. Cement specimens by curing 28d containing 8 % TOS exhibited a 27.8 % increase in flexural strength, a 48.7 % reduction in elasticity modulus and a 33.8 % reduction in brittleness coefficient. The addition of TOS can effectively improve the toughness of cement. The average pore size of specimens containing 8 % TOS admixture decreased to 9.17 nm. This indicates that TOS enhanced the structural density of cement materials. The crack about 103μm in the cracking specimens with 8 % TOS was almost healed, and the corresponding permeability was reduced 99.1 % after curing in oil. Adsorption and film formation of TOS can resist the cracking of cement sheath, and the oil swelling expansion of film in cement matrix can repair the cracked structure.

The frame around a test specimen and its influence on the measured sound absorption coefficient

For most practical cases of reverberation room measurements of sound absorption coefficient according to ISO 354:2003, the standard requires the edges of the test specimen to be covered by a reflective frame. The purpose of this requirement is to keep the edges of the test specimen from absorbing sound. While this statement is consistent with practical measurement results at medium to high frequencies, it has been shown that the low frequency performance of a high-absorbing test specimen worsens when a frame is not in place. To further investigate this phenomenon, a series of reverberation room measurements have been carried out on several variations of a porous absorber test specimen. The goal of the measurements has been to determine whether the size and dimensions of the test specimen affect the test results, and if any such affections are dependent on the presence of a frame. Additionally, the sound absorption area of the frame itself has been measured to elucidate whether the frame is likely to give a significant contribution to the total sound absorption area of a framed test specimen. The results will be presented and discussed in this paper.

Factors Influencing Measurement of Dynamic Elastic Modulus from Disk-Shaped Concrete Specimen

The decrease in dynamic elastic modulus is a primary indicator of quantitative damage in concrete. To quantitatively assess depth-by-depth damage within a concrete structure, cylindrical specimens obtained through coring can be cut into disk specimens to measure the dynamic elastic modulus of concrete at each depth. To minimize external damage during coring, it is essential to extract cylinders with the smallest possible diameter. In addition, for higher resolution in depth-based damage assessment, creating disk specimens with the smallest possible thickness is necessary. However, there is no information available in the literature on experimental limitation of smallest possible diameter and thickness for dynamic elastic modulus of disk-shaped specimens. This study evaluated whether the dynamic modulus measured from various sizes of concrete disk specimens provided sufficient reliability compared to reference values obtained from cylinders. Moreover, the study examined how the presence of coarse aggregate and variation in the water–cement ratio significantly influenced the dynamic modulus measurement. In addition, test results from impulse excitation technique (IET) and impact resonance (IR) were compared to find a more reliable test method for dynamic elastic modulus of disk specimen. The experimental findings revealed that as the thickness-to-radius ratio of the disk specimens decreased, measured data variation increased. Mortar specimens without coarse aggregates showed less variability compared to concrete specimens, and the variation in dynamic modulus measured by IR was lower than that measured by IET.

New guidelines for ISO 9053 based on CFD simulations of the static airflow resistivity of a perforated solid

The acoustic absorption coefficient of the acoustic absorbers is directly impacted by the airflow resistivity. The ISO 9053 explains the measurement procedure and specify the size and mounting of specimens, and the flow velocities. The main constraint of the standard is to maintain a stable linear flow so that the resistance is independent of the velocity. Additionally, it suggests a straight cylindrical pores specimen whose airflow resistivity value can be calculated theoretically. Any other specifications about the calibration specimen design are given. As the flow dynamics inside the perforated low porosity solid behave nonlinearly, it is important to integrate further guidelines in the design of the calibration specimens and measurements. This work presents CFD calculations results using OpenFoam, on the flow resistivity of a cylindrical solid containing a single perforation. The airflow velocity was determined based on the Reynolds number at the pore, which was varied between 0.33 to 2000. Different calibration specimens were tested by varying the length and the perforation diameter. An excellent agreement was observed between CFD and experimental data with an error of 5 %. The results show that the second-order extrapolation of specific resistance should be limited to Reynolds numbers equal to 500.

Experimental and analytical study on the compressive behavior of PMI foam with different densities and cell sizes under intermediate strain rates

Polymethacrylimide (PMI) foam materials have great potential for applications in the field of protective energy absorption owing to their superior compressive properties. Existing studies on the mechanical behavior of PMI foams are limited, particularly for loading at intermediate strain rates. This paper presents a comprehensive experimental study of PMI foam with four different densities under quasi-static and intermediate strain rate compression (0.001 s−1 to 100 s−1). Each density included three different cell sizes to determine their effects on the compressive performance. Loads parallel and perpendicular to the foam rise direction were considered to investigate the anisotropic behavior. Intermediate strain rate tests were conducted using a high-speed hydraulic servo testing machine, which achieved a stable strain rate while ensuring consistent specimen sizes in both quasi-static and dynamic tests. In all the experiments, the compression process was captured using a high-speed camera and the macroscopic deformation mode and microscopic deformation mechanism were analyzed by combining Digital Image Correlation (DIC) and Scanning Electron Microscopy (SEM). The PMI foam with finer cell sizes exhibited an enhanced compression performance. As the strain rate increased, the strain rate effect became more evident in the high-density specimens and an increase in cell size diminished this effect. A modified analytical model incorporating the cell-size correction term was developed based on Gibson and Ashby's model. The modified model exhibited an average error of 4.9 % in the predicted plateau stress of PMI foam with different cell sizes at the same density.

Tensile strength of MgO-graphite based refractories: effect of anisotropy and specimen size

Oxide-graphite refractories represent the new paradigm of materials for extreme environments since 1970´s: materials that resist thanks to "in situ" microstructural changes. The analysis of post-mortem linings necessitates the use of small specimens because main microstructural changes occur within the matrix, exhibiting zonal distributions relatively small compared to maximum aggregate sizes. In this paper the minimized tensile strength of discs (diameter=18 mm, width=8 mm) tested in diametral compression is addressed for commercial materials representative of the typical microstructures. Effects of aggregate and graphite sizes, graphite anisotropy and size of the specimens on the quasi-brittle fracture of these heterogeneous materials are discussed.

Flash sintering of AlN ceramics with Y2O3 additive

This study demonstrates the fabrication of dense AlN-based ceramics through the flash sintering technique for the first time. Flash sintering was performed at a furnace temperature of 1500 °C with 10 wt% Y2O3 as a sintering aid in a nitrogen atmosphere. The effects of the current density and holding time on the microstructure evolution and mechanical properties were investigated. The results show that the relative density, grain size and Vickers hardness of specimens increase with increasing current density and holding time. The specimen showed the highest relative density of 98.6% and a Vickers hardness of 12.68 GPa when a current density of 100 mA/mm2 and a holding time of 60 min were used. Additionally, the grain sizes at the positive side of the electrodes were found to be larger than those at the negative side. These findings suggest that dense AlN-based ceramics can be fabricated in a rapid and efficient way through the flash sintering technique.

Novel reopenable clip with anchor prongs facilitates mucosal defect closure after colorectal endoscopic submucosal dissection: Pilot feasibility study (with video).

Closure of mucosal defects following colorectal endoscopic submucosal dissection (C-ESD) is often performed to prevent post-C-ESD adverse events. However, large mucosal defect closure using conventional clips remains technically challenging. Here, we evaluated the feasibility of the novel endoclip with anchor prongs, called the MANTIS Clip (Boston Scientific, Tokyo, Japan), for mucosal defect closure after C-ESD. This high-volume retrospective study was conducted at a single center. From March until December 2023, consecutive patients who underwent post-C-ESD mucosal defect closure using MANTIS Clip to achieve complete closure were enrolled. Patient clinical characteristics and outcomes were evaluated. Closure of the mucosal defect using the MANTIS Clip was attempted following C-ESD in 32 lesions. The median sizes of the resection specimens and the tumors were 32 mm (range, 17-100 mm) and 23.5 mm (range, 5-96 mm), respectively. The lesions were distributed between the cecum, ascending, transverse, descending, sigmoid, and rectum. Complete closure was achieved in 96.9% of cases (31/32). All lesions up to 61 mm in defect size were completely closed. The median closure time was 7.9 (range, 3.3-18.0) min. The median numbers of MANTIS Clip and additional conventional clips were 3 (range, 1-4) and 5 (range, 1-11), respectively. No adverse events associated with closure, post-ESD bleeding, and delayed perforation occurred. MANTIS Clip closure for large post-C-ESD mucosal defects was found to be feasible and reliable with a high complete closure rate and a short procedure time.

Redescription of Raillietiella mottae (Raillietiellidae: Pentastomida) a generalist parasite of insectivorous lizards: phenotypic plasticity revealed by molecular data.

Pentastomida are lung parasites of a variety of hosts, mainly reptiles. Raillietiella is the genus with the largest number of species, whose taxonomic identification is still largely based on morphological data alone. In this classification, differences divide the genus into morphotypic groups. The Raillietiella parasites of insectivorous lizards, for example, are divided into "Group I" with species with hooks with sharp tips and "Group II" with posterior hooks with blunt tips. In the present work, we used molecular analysis to infer the morphological variation in hooks and size of specimens of Raillietiella mottae, parasites of several species of insectivorous lizards. Our results demonstrate that morphological differences comprise a phenotypic plasticity of a single species, whose variation is associated with host species, with females being larger and with hooks with blunt tips in nocturnal geckos and smaller ones with sharp tips in diurnal insectivorous lizards of different species, sizes, and habitats.