Segmental Distribution Research Articles

Adult-Onset Eccrine Angiomatous Hamartoma Associated with Lower Extremity Venous Insufficiency: A Case Report

Introduction: Eccrine angiomatous hamartoma (EAH) is a benign tumor characterized by the proliferation of eccrine glands and vascular structures. It can be congenital or appear during childhood, with rare cases arising in adults. EAH typically presents as a solitary purplish plaque or nodule but a multifocal presentation in a blaschkoid or segmental distribution has been described. Case Presentation: We report the case of an extensive EAH following the territory of the superficial veins of the lower limbs, arising in an adult diagnosed with venous insufficiency at a young age and that worsened after saphenectomy. Conclusion: The histopathological and ultrasonographic characteristics suggest that this case may represent a new instance of EAH associated with arteriovenous malformation. We hypothesize that there might be common molecular pathways linking both conditions and that, in predisposed patients, saphenectomy can exacerbate EAH.

Assessment of Nonmass Lesions Detected with Screening Breast US Based on Mammographic Findings.

Background Breast nonmass lesions (NMLs) are observed at screening and diagnostic US. However, knowledge is limited on imaging features of NMLs at screening US. Purpose To identify features of NMLs at screening US that are suspicious for malignancy based on mammographic findings. Materials and Methods This retrospective, multicenter study included asymptomatic women who underwent screening US between January 2012 and December 2019. Eligible women had NMLs at US, concurrent screening mammography, and record of a final diagnosis. Logistic regression analyses were used to identify factors associated with malignancy. The diagnostic performance of each sonographic feature according to mammographic findings was calculated. A reader study was performed to assess interreader agreement for sonographic features. Results Among 993 NMLs in 993 patients (mean age, 50 years ± 9 [SD]), 914 (92.0%) were benign and 79 (8.0%) were malignant. Mean size was larger for malignant NMLs than for benign NMLs (2.6 cm ± 1.1 vs 1.9 cm ± 0.8; P < .001). In multivariable analysis, associated calcifications (odds ratio [OR], 21.6 [95% CI: 8.0, 58.2]; P < .001), posterior shadowing (OR, 6.9 [95% CI: 2.6, 18.4]; P < .001), segmental distribution (OR, 6.2 [95% CI: 2.7, 14.4]; P < .001), mixed echogenicity (OR, 5.0 [95% CI: 1.8, 14.0]; P < .001), and size (OR, 1.5 [95% CI: 1.1, 2.1]; P = .01) at US were associated with malignancy. Associated calcifications, posterior shadowing, segmental distribution, and mixed echogenicity showed positive predictive values (PPVs) of 44%, 22%, 22.9%, and 16.6%, respectively. Having a negative mammogram was associated with a lower malignancy rate (2.8% vs 28.8%) and lower PPVs for sonographic features (0.7%-10.4% vs 24%-55%) than having a positive mammogram. Interreader agreement for sonographic features was good to excellent (Fleiss κ 95% CI lower bound range, 0.63-0.81). Conclusion Calcifications, posterior shadowing, segmental distribution, and mixed echogenicity associated with NMLs can be considered suspicious features for malignancy at screening US. As malignancy rates and PPVs differ according to mammographic abnormalities, combined assessment is mandatory. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Grimm in this issue.

Prevalence of an empty colon in patients with acute and chronic small intestinal mechanical obstruction: A retrospective radiographic study in 100 dogs and cats

Small intestinal mechanical obstruction (SIMO) is a common clinical condition, with radiographic studies typically focusing on the small intestine. However, the colon's appearance in SIMO has not been extensively studied. This retrospective study aimed to determine the prevalence of an empty colon on radiographs of dogs and cats with confirmed SIMO. Pre-surgical abdominal radiographs of 100 patients (68 dogs and 32 cats) with surgically confirmed mechanical ileus and a control group of 30 dogs and 20 cats with non-obstructive gastrointestinal (GI) disease and one without GI disease, respectively, were evaluated. The colon was assessed for content (none/collapsed, gas, faeces) and segmental distribution (ascending, transverse, descending colon) and correlated to the duration of clinical signs (acute, chronic). A colon was classified as empty when ≥2/3 was collapsed and/or gas-filled. The overall prevalence of an empty colon in cases of mechanical ileus was 61% (p=0.028), with 49/68 in dogs (72.1%) and 12/32 in cats (37.5%), p=0.001 between dogs and cats. Clinical signs duration did not influence the prevalence 28/61 (45.9%) acute, 33/61 (54.1%) chronic, p=0.522. However, acute cases had more empty colon segments (2/3 segments: 6/28, 21.4%; 3/3 segments: 22/28, 78.6%) than chronic cases (2/3 segments: 23/33, 69.7%; 3/3 segments: 10/33, 30.3%; p≤0.001). In the control groups, the prevalence of an empty colon was 64% (p=0.048) with and 38%, p=0.048) without GI disease, with no statistical difference between dogs and cats. An empty colon can be a supporting radiographic finding in diagnosing patients with GI disease, including SIMO, in addition to other established characteristic features. Dogs are more likely to have an empty colon in the presence of mechanical ileus.

Aqueous Humor Angiography.

Aqueous humor angiography, or aqueous angiography, is an anterior segment imaging technique capable of visualizing the conventional/trabecular aqueous humor outflow pathways. As a translational technique, it is applicable for in vivo imaging in living subjects and ex vivo imaging using whole-globe preparations or anterior segment perfusion setups. Excellent spatial and temporal resolution has enabled insights into the segmental distribution of aqueous humor outflow in physiological conditions as well as after trabecular bypass surgery. In this chapter, we thoroughly describe aqueous humor angiography in various experimental setups. The necessary materials for different settings and their application for in vivo and ex vivo experiments as well as notes on dye choice, dye sequences, and special considerations on performing aqueous humor angiography during surgery are presented.

Nomogram based on multimodal ultrasound features for evaluating breast nonmass lesions: a single center study

BackgroundIt is challenging to correctly identify and diagnose breast nonmass lesions. This study aimed to explore the multimodal ultrasound features associated with malignant breast nonmass lesions (NMLs), and evaluate their combined diagnostic performance.MethodsThis retrospective analysis was conducted on 573 breast NMLs, including 309 were benign and 264 were malignant, their multimodal ultrasound features (B-mode, color Doppler and strain elastography) were assessed by two experienced radiologists. Univariate and multivariate logistic regression analysises were used to explore multimodal ultrasound features associated with malignancy, and a nomogram was developed. Diagnostic performance and clinical utility were evaluated and validated by the receiver operating characteristic (ROC) curve, calibration curve and decision curve in the training and validation cohorts.ResultsMultimodal ultrasound features including linear (odds ratio [OR] = 4.69) or segmental distribution (OR = 7.67), posterior shadowing (OR = 3.14), calcification (OR = 7.40), hypovascularity (OR = 0.38), elasticity scored 4 (OR = 7.00) and 5 (OR = 15.77) were independent factors associated with malignant breast NMLs. The nomogram based on these features exhibited diagnostic performance in the training and validation cohorts were comparable to that of experienced radiologists, with superior specificity (89.4%, 89.5% vs. 81.2%) and positive predictive value (PPV) (89.2%, 90.4% vs. 82.4%). The nomogram also demonstrated good calibration in both training and validation cohorts (all P > 0.05). Decision curve analysis indicated that interventions guided by the nomogram would be beneficial across a wide range of threshold probabilities (0.05-1 in the training cohort and 0.05–0.93 in the validation cohort).ConclusionsThe combined use of linear or segmental distribution, posterior shadowing, calcification, hypervascularity and high elasticity score, displayed as a nomogram, demonstrated satisfied diagnostic performance for malignant breast NMLs, which may contribute to the imaging interpretation and clinical management of tumors.

Quantified growth and possible heterochronic development of two corynexochid trilobites from the middle Cambrian (Miaolingian Series, Wuliuan Stage) Mount Cap Formation, eastern Mackenzie Mountains, northwestern Canada

Abstract The ontogeny of two species of corynexochid trilobites from the middle Cambrian Mount Cap Formation of the eastern Mackenzie Mountains, northern Canada, is documented. Sahtuia carcajouensis (Dolichometopidae) and Mackenzieaspis parallelispinosa (Zacanthoididae) are both endemic to this formation and only known from one locality. They, along with several other corynexochid taxa, occur in a succession of mudstone with scattered carbonate interbeds, deposited in a weakly storm-agitated setting near the flank of a semi-enclosed basin. The ontogeny of both species is characterized by mainly normal cranidial development, but a unique distribution of segments in their thoraxes and pygidia. The number of trunk segments was typical for their respective families, whereas the final number of segments released into the thorax was reduced. This occurred in both species through timing modifications to segment release, indicating heterochrony. Sahtuia carcajouensis and Mackenzieaspis parallelispinosa are likely derived from two separate clades, and heterochrony probably arose separately but synchronously. The endemicity of both species probably reflects unique paleoecological conditions in this part of the basin. Preliminary results indicate that the fossil-bearing mudstone was deposited under well-oxygenated conditions that underwent high nutrient flux and possibly experienced varying salinity. These factors may have affected the organisms’ physiology, or perhaps provoked an adaptation to achieve early maturation.

Predictors of breast cancer HER2-receptor positivity by MRI intuitive imaging features

BackgroundToday, breast cancer is the most diagnosed cancer worldwide. There are many different clinical presentations, radiological characteristics, and histological types of breast cancer. HER2 is overexpressed in a significant number of breast cancer cases reaching 20% of all breast cancers, and its overexpression is seen directly proportionate with a poor outcome and prognosis.MethodsWe started this cross-sectional research from January 2022–December 2023 on 202 breast cancer patients who had 220 lesions. The molecular subtypes of the different lesions were determined in all the included cases. Magnetic resonance imaging (MRI) studies were conducted in all included cases. The MRI parameters included conventional MRI, diffusion-weighted analysis, and dynamic post-contrast T1-weighted imaging.ResultsThe prevalence of irregular margins (P < 0.001), linear and segmental distribution (P = 0.044), heterogeneous pattern (P < 0.001), and type 2 curve was statistically significantly higher in the HER2-positive lesions. Nipple infiltration incidence showed statistically significant elevation in the HER2-positive lesions (P = 0.017). The lesions’ ADC and perilesional ADC in the HER2-positive lesions were also statistically significantly elevated. The best cutoff point of ADC to detect lesions with positive HER2 expression was > 0.885 × 10–3 mm2/s, with 65.7% sensitivity and 60% specificity, with a statistically significant value (p = 0.005).ConclusionsMagnetic resonance imaging of breast imaging is a promising noninvasive method for identifying breast tumors with the HER2 molecular subtype. Combining various radiological features by MRI may provide a conclusion for recognizing positive HER2 lesions.

A Novel Ultrasound Finding for the Diagnosis of GiantCellArteritis: Comparison With Temporal ArteryBiopsy Findings.

Hypoechoic halo is a typical ultrasound finding in giant cell arteritis (GCA), but it may be a false positive due to arteriosclerosis. Therefore, we focused on the segmental distribution of GCA lesions, defined the luminal irregularity in long-axis images as the string of beads sign, and examined its diagnostic ability. As a result, the C-statistic of hypoechoic halo and string of beads sign was better than that of hypoechoic halo alone (1.00 vs. 0.89). Based on the above, the diagnostic ability of GCA can be improved by adding the string of beads sign to the conventional hypoechoic halo.

Digital breast tomosynthesis for early detection of malignant breast microcalcification: A hospital-based cross-sectional study

Background: Breast cancer is the leading cause of cancer-related deaths in women. Early detection by screening is crucial for improved survival. Digital breast tomosynthesis (DBT) may offer better visibility than conventional screening. This study aims to assess the diagnostic accuracy of DBT in detecting malignant breast microcalcifications compared to histopathological findings. Methods: This cross-sectional study was done at the Department of Radiology and Imaging, Bangabandhu Sheikh Mujib Medical University, Dhaka, from July 2022 to June 2023 and enrolled 35 women suspected of having breast cancer. Each patient underwent DBT and histopathology tests. The diagnostic accuracy of DBT in detecting malignant breast microcalcifications was assessed compared to the gold standard of histopathology. Results: The average age of the participants was 48.6 years. Palpable breast lumps (91.4%) were the most common clinical presentation. Among them, 80% had malignant microcalcifications diagnosed by DBT, primarily with linear (40.0%) and segmental (28.6%) distribution. Histopathology identified 80% of cases as malignant, with ductal carcinoma in situ (34.3%) being the most prevalent type. DBT demonstrated high sensitivity (100%) and specificity (85.7%) in detecting malignant microcalcifications, resulting in an overall accuracy of 97.1%. Conclusions: DBT has high diagnostic accuracy for detecting malignant breast microcalcifications and can be considered a valid tool for the early detection of breast microcalcifications, particularly in the context of diagnosing breast cancer.

The Predictive Role of Mammography, Dynamic Contrast-Enhanced Breast Magnetic Resonance Imaging and Diffusion-Weighted Imaging in Hormone Receptor Status of Pure Ductal Carcinoma In Situ Lesions.

The aim of this retrospective study was to analyze the predictive capabilities of preoperative mammography, dynamic contrast-enhanced-magnetic resonance imaging (DCE-MRI), and diffusion-weighted imaging (DWI) in determining hormone receptor (HRc) status for pure ductal carcinoma in situ (DCIS) lesions. The study included a total of 79 patients who underwent preoperative mammography (MG) and MRI between December 2018 and December 2023 and were subsequently diagnosed with pure DCIS after surgery. The correlation between MG, DCE-MRI, and DWI features and estrogen receptor (ER) and progesterone receptor (PR) status was examined. Among the lesions, 44 were double HRc-positive (ER and PR-positive), 13 were single HRc-positive (ER-positive and PR-negative or ER-negative and PR-positive) and 22 were double HRc-negative (ER and PR-negative). The presence of symptom (p = 0.029), the presence of comedo necrosis (p = 0.005) and high histological grade (p<0.001) were found to be associated with ER and PR negativity. Amorphous microcalcifications were more commonly observed in the double HRc-negative group, while linear calcifications were more prevalent in both double and single HRc-positive groups (p = 0.020). Non-mass enhancement (NME) with a linear distribution was significantly more common in double HRc-negative lesions (38%), and NME with a segmental distribution in both double (43%) and single (50%) receptor-positive lesions (p = 0.042). Evaluation of DWI findings revealed that a higher lesion-to-normal breast parenchyma apparent diffusion coefficient (ADC) ratio statistically increased the probability of HRc positivity (p = 0.033). Certain clinicopathological, mammography, and MRI features, along with the lesion-to-normal breast parenchyma ADC ratio, can serve as predictors for HRc status in DCIS lesions.

Ameliorated lipid distribution in prediabetes - Effects of 12 weeks traditional Chinese YiJinJing exercise plus TheraBand: A randomized controlled trial

ObjectiveLipid distribution plays a crucial role in glucose metabolism, and this study aimed to investigate the effects of 12 weeks traditional Chinese YiJinJing exercise on specific lipid distributions in patients with prediabetes. MethodsSixty participants with prediabetes were randomly allocated to either a control group (Con, n = 30) or an exercise group (Ex, n = 30). The Ex group underwent YiJinJing exercise plus Theraband, engaging in 1-h sessions, 3 times per week, over a total period of 12 weeks. Dual-energy X-ray absorptiometry (DEXA) and magnetic resonance imaging (MRI) were used to measure lipid distribution in different body segments and organs. Additionally, a body composition analyser was employed to measure visceral fat, and laboratory tests were conducted to measure indicators related to glycolipid metabolism. ResultsFollowing a 12-week intervention with Exercise, 37 % of prediabetic patients in the Ex group achieved normal blood glucose levels. Significant reductions were observed in upper limb fat (ULF), trunk fat (TrF) and liver fat (LF) values in the Ex group compared to the Con group. Additionally, within the Ex group, there were notable decreases in triglyceride (TG) levels, body mass index (BMI), waist-hip ratio (WHR), android fat (AF), ULF, thigh fat (ThF), renal sinus fat (RSF), and LF compared to baseline. ConclusionsTraditional Chinese YiJinJing plus TheraBand exercise can significantly reduce blood glucose levels through improved lipid distribution and metabolism in prediabetic patients. Hence, YiJinJing can serve as a crucial intervention for individuals with prediabetes.

Segmental vitiligo distribution follows the underlying arterial blood supply territory: a hypothesis based on anatomo-clinical, pathological and physio-pathological studies.

Segmental vitiligo (SV) is a subset of vitiligo typically characterized by its unilateral distribution. The pathogenesis of SV remains unclear, and until now the two main patterns proposed for SV have lacked biological support. This calls for a new approach. Use data obtained from anatomo-clinical, pathological, and physio-pathological studies to formulate a new hypothesis on segmental vitiligo distribution and its pathogenesis. Using transparent templates of local arterial blood supply, we evaluated anatomical correspondence (AC) in 140 SV lesions according to the number of SV lesions that fit within the corresponding arterial blood-supply areas. SV lesions were graded as 1 (moderate: AC < 50%), 2 (good: AC > 50%), or 3 (excellent: AC of all lesions). To support this anatomical investigation, we searched for complementary assessments according to the activity of SV lesions. Arterial and periarterial network impairment and inflammatory infiltration were histologically studied using nerve growth factor (NGF) and CD4 and CD8 monoclonal antibodies. Increased blood flow of the underlying arteries was also investigated using thermography and ultrasonography. We recruited 140 patients with a sex ratio of 0.8 and mean age 26.13 years. Localizations: head and neck 84.28%; trunk 6.42%; upper limb 5%; genital areas 2.14%; lower limb 1.42%. The AC of each SV lesion with the underlying artery blood supply territory was rated as 72% excellent; 16% good; and 12% moderate. Histologically (40 patients), we found some periarterial network impairments. Thermal asymmetry was significantly associated with active SV (p < 0.001). We hypothesized that SV distribution corresponds to the underlying artery blood-supply territory.

Housing Market Segmentation as a Driver of Urban Micro-Segregation? An In-Depth Analysis of Two Viennese Districts

The concept of segregation analyses the unequal distribution of social groups between neighbourhoods. It rests on two assumptions: that of homogeneous neighbourhoods and of a market liberal housing system. Both assumptions are applicable the context of American cities, but they display severe limitations when applied to the European context. Vienna’s housing market is particularly highly segmented, not only throughout the city as a whole but also within neighbourhoods. In the densely built-up area, residential buildings of different segments with different underlying rent regulations and entry barriers can be found side by side. Therefore, buildings are expected to show varying tenant and owner structures, which undermines the idea of a homogeneous neighbourhood. Against this background, we analyse at the micro scale small neighbourhoods defined by 100 m grid cells in a case study of two inner-city Viennese districts (districts 6 and 7) characterised by a particularly vivid housing-transformation and commodification dynamic. Using a novel and fine-grained dataset combining building information with the socio-economic data of households, we investigate the patterns and dynamics of income inequality and income segregation, as well as the relationship between housing market segments and socio-economic patterns. As data comprise two cross-sections for the years 2011 and 2020/21, changes in the neighbourhoods during the house-price boom period are also considered. This leads us to ask the question: How do housing market segmentation and its related changes affect income inequality and segregation at the micro scale? Our analysis delivers two main results: Firstly, we show the existence of marked social variation and related dynamics at the micro scale, even within a small urban area. Secondly, we show that the spatial distribution of housing market segments has a strong impact on income inequality in the neighbourhood.

Electrophoresis of polyelectrolyte-adsorbed soft particle with hydrophobic inner core.

This article deals with the electrophoresis of hydrophobic colloids absorbed by a layer of polymers with an exponential distribution of the polymer segments. The functional groups present in the polymer layer further follow the exponential distribution. We made an extensive mathematical study of the electrophoresis of such core-shell structured soft particles considering the combined impact of heterogeneity in polymer segment distribution, ion steric effect, and hydrodynamic slippage of the inner core. The mathematical model is based on the flat-plate formalism and deduced numerical results for electrophoretic mobility are valid for weak to highly charged particles for which the particle size well exceeds the Debye-layer thickness. In addition, we have derived closed form analytical results for electrophoretic mobility of the particle under several electrohydrodynamic limits. We have further illustrated the results for electrophoretic mobility considering a charged and hydrophobic inner core coated with an uncharged polymer layer or a polymer layer that entraps either positive or negatively charged functional groups. The impact of pertinent parameters on the overall electrophoretic motion is furtherillustrated.

Disaster mechanism of large-diameter shield tunnel segments under multi-source load coupling: A case study

The deflection squeezing of the shield shell and the eccentric jack thrust significantly impact the segment dislocation and damage. Based on summarizing the derivative relationship between engineering factors and disasters, this study established a 3D numerical calculation model under the multi-source load coupling. Then, this study explored the displacement and dislocation distribution of segments, as well as their derivative relationship with bolt failure. Furthermore, this study analyzed the spatial distribution and evolution characteristics of segment damage. Further revealing the disaster mechanism and proposing the engineering treatment measures. The research results indicate that as the deflection angle increases, the vertical relative compression deformation of the segment that is detaching from the shield tail (segment-DFST) becomes more significant. The plastic strain of the internal bolts inside the two segments in direct contact with the shield shell is mainly related to the radial and longitudinal dislocation. The increase in the deflection angle will lead to a more significant increase in the adjacent dislocation on both sides and the internal dislocation. The plastic strain of the internal bolts of the segment that is completely in the shield shell (segment-CSS) is more influenced by joint opening and longitudinal dislocation under the lower eccentric compression (LEC) state. The plastic strain of the internal bolts in segment-DFST is more influenced by radial dislocation and joint opening under the LEC state. The tension damage of the segments mainly occurs on both sides of the circumferential joint and the lower part of the segment-CSS. The compression damage of the segments is mainly distributed at the top and bottom of the segment-CSS. The eccentric distribution of jack thrust has the most significant impact on the block damage of the lower part of the segment-CSS. With the increase of the deflection angle, the compression damage and distribution range of the blocks at the bottom of the segment-DFST increase sharply. The compression damage and distribution range of the segment-CSS gradually spread from the upper and lower parts to the middle of the segment. The increase in deflection angle will promote the influence of the thrust in LEC state on the compression damage of the lower block of the segment-CSS, and on the tension damage of the upper block of the segment- DFST.

Clinicopathological characteristics of neural epidermal growth factor-like 1 protein-associated membranous glomerulonephritis.

Neural epidermal growth factor-like 1 protein (NELL1) is the second most common target antigen in membranous glomerulonephritis (MGN). However, data regarding the clinicopathological characteristics of NELL1-associated MGN are limited owing to its low prevalence. This study examined the prevalence and clinicopathological characteristics of NELL1-associated MGN in a Japanese cohort. Additionally, we compared the clinicopathological features of NELL1-positive MGN, phospholipase A2 receptor 1 (PLA2R1)-positive MGN, and MGN negative for all three antigens (NELL1, PLA2R1, and thrombospondin type-1 domain-containing 7A). Among 257 consecutive patients pathologically diagnosed with MGN at two centers in Japan, 24 (9.3%) were immunohistochemically positive for NELL1. Clinically, patients with NELL1-positive MGN were significantly older (p < 0.001) and had a higher frequency of bucillamine use (vs PLA2R1-positive MGN, p < 0.01). Histologically, NELL1-positive MGN exhibited significantly lower detection of spikes and crater formation (p < 0.001), higher prevalence of segmental spike distribution (vs PLA2R1-positive MGN: p < 0.001), and higher prevalence of stage I cases on electron microscopy (p < 0.01). There were no significant differences in the prognoses among the three groups. The characteristic histological feature of segmental distribution in NELL1-positive MGN may be related to bucillamine use and the early phase of the disease. Further investigations with larger numbers of patients may offer further insight into the prognosis of patients with NELL1-positive MGN.

The effect of silicon incorporation on hybrid polyurethane‐imide elastomers with graphite flakes: Unique microstructures, conducting properties, and mechanical properties

AbstractIn this paper, a series of silicon hybrid polyurethane‐imides (SPUI) with high stability were constructed by introducing diphenylsilanediol (DPSD) and imidization effect, in which the segment character and hydrogen bonding were adjusted. Various “sea‐island” microphase separations, similar evolution from blooming flower to bud like microdomains was originating from the hard segment clusters, where the segment distribution was labeled and visualized by the stacking of silicon heteroatom. Comparing with pure polyurethane (PU), tensile strength and elongation at break for SPUIs increased from 0.71 ± 0.04 to 17.67 ± 1.84 MPa and from 84.39% ± 6.79% to 202.38% ± 14.50%, respectively. Interestingly, the silicon‐induced aggregates of hard segments in SPUI/graphite flakes (SPUI/GFs), densely crowded around GFs except for some dispersions, revealing similar coupling agent characters of SPUI and self‐affinity with GFs. Thus, the high performance was achieved due to adjustable percolation and cross‐linking networks. Percolation thresholds were decreased from 2.04 to 0.61 wt% and the conductivity of 1.0 × 100 S/m at GFs contents of 5.0 wt% for SPUIz/GFs‐500 was achieved, 2–3 orders of magnitude higher than that of SPUIz/GFs‐2000 except for high stability in conductivity, far lower than those of reported composites. Finally, this study was of great significance for developing functional PU materials with high performance.

Segmental congenital vascular anomaly with atrophy, ulceration, and scarring (SeCVAUS): Case series and review of literature.

Next-generation sequencing has greatly increased our understanding of vascular birthmarks. Many port-wine birthmarks are due to somatic mutations in GNAQ/GNA11 exon 183, but other genomic causes have been identified. Most congenital hemangiomas are due to somatic mutations in GNAQ/GNA11 at exon 209. Although genomically distinct, clinical overlap of congenital hemangiomas and port-wine birthmarks has occasionally been described. We report a case series of a unique segmentally distributed vascular anomaly with overlapping characteristics of port-wine birthmarks and congenital hemangiomas with other distinctive features including ulceration, atrophy, and scarring. This was a multicenter study with retrospective identification of patients via a detailed review of medical records. We also reviewed previously published cases. The clinical, histological, radiological, and genomic characteristics of 19 new and 13 previously reported cases characterized by segmental distribution, sharply demarcated borders, with variable thickening are presented. All cases had central atrophy with or without episodic ulceration. Those with genomic studies (13 out of 32) had somatic activating missense mutations in GNA11 or GNAQ codon 209. We describe the features and propose a descriptive name segmental congenital vascular anomaly with atrophy, ulceration, and scarring (SeCVAUS) for this condition.

Research on circumferential joint shear damage characteristics of segments with positioning tenon through distributed fiber optic-based sensing technique

Positioning tenons have been used in more and more subway projects to improve segment assembly performance and to limit the occurrence of common problems between segments. The joints are the weak parts of the segment connection and are often damaged during construction. However, there are limited studies on the joints of segments with positioning tenons, and their damage characteristics have yet to be investigated. In this study, circumferential joint shear damage in segments with positioning tenons is studied and the evolution of the distributed damage is monitored by distributed fiber optics. First of all, the shear performance of segments with positioning tenons is investigated under different axial forces. Particularly, the damage distribution and development of segments subjected to the extrusion of the positioning tenons are analyzed through the strain signals and the macroscopic cracks during the shearing process. Furthermore, the changes in the strain signals of the distributed fiber before shear failure are analyzed. Based on the above study, the failure patterns of the inner surfaces and circumferential joint surfaces of segments with grooves are revealed. The interaction between the positioning tenons and the segments is analyzed, and the damage characteristics of the tenons are obtained. Finally, the main crack shear coefficient is proposed to evaluate the residual shear performance of segments when the macroscopic main crack occurs on the inner surface. This study aims to reveal the interaction between positioning tenons and segments and to promote the application of positioning tenons in subways. Further, it lays the foundation for optimizing the flexible joints of segments in subways and contributes to the safe construction of subway tunnels.

Robot-assisted versus traditional fluoroscopy-assisted posterior fixation in treatment of thoracolumbar fractures with ankylosing spondylitis: a retrospective study

To compare the effectiveness of robot-assisted (RA) minimally invasive surgery versus traditional fluoroscopy-assisted (FA) open posterior fixation surgery in treating thoracolumbar fractures with ankylosing spondylitis (AS). A clinical data of 21 cases of thoracolumbar fractures with AS who met the selection criteria between December 2016 and December 2023 was retrospectively analyzed. Ten cases underwent RA minimally invasive surgery group (RA group) and 11 cases underwent FA open posterior fixation surgery (FA group). There was no significant difference in gender, age, fracture segment distribution, fracture type, time from injury to surgery, visual analogue scale (VAS) score, and American Spinal Injury Association (ASIA) grading between RA group and FA group ( P>0.05). The operation time, intraoperative blood loss, radiation exposure time, radiation dose, hospital stay, and complications of the two groups were recorded. According to Gertzbein-Robbins criteria, the accuracy of screw implantation was evaluated by CT within 1 week after surgery. During follow-up, pain and nerve function were evaluated by VAS score and ASIA grading. All patients underwent surgery successfully, and there was no significant difference in operation time ( P>0.05). The intraoperative blood loss and hospital stay in the RA group were significantly less than those in the FA group ( P<0.05), and the radiation exposure time and radiation dose were significantly more than those in the FA group ( P<0.05). A total of 249 pedicle screws were implanted in the two groups, including 118 in the RA group and 131 in the FA group. According to the Gertzbein-Robbins criteria, the proportion of clinically acceptable screws (grades A and B) in the RA group was significantly higher than that in the FA group ( P<0.05). Patients in both groups were followed up 3-12 months, with an average of 6.8 months. The VAS scores of the two groups after surgery were significantly lower than those before surgery, and the differences were significant ( P<0.05). The RA group had lower scores than the fluoroscopy group at 1 week and 3 months after surgery ( P<0.05). There was no significant difference in neurological function grading between groups at 1 week and 3 months after surgery ( P>0.05). In the FA group, 1 case of deep infection and 1 case of deep vein thrombosis of lower extremity occurred, while no complication occurred in the RA group, and there was no significant difference in the incidence of complications between groups ( P>0.05). Both RA minimally invasive surgery and FA open posterior fixation surgery can achieve good effectiveness. Compared with the latter, the former has more advantages in terms of intraoperative blood loss, hospital stay, and accuracy of pedicle screw insertion.