Grading Scheme Research Articles

Effect of Fenofibrate on Progression of Diabetic Retinopathy

BackgroundFindings from cardiovascular outcome trials suggest that fenofibrate therapy may reduce the progression of diabetic retinopathy.MethodsWe recruited and followed adults with nonreferable diabetic retinopathy or maculopathy using the national Diabetic Eye Screening (DES) program in Scotland. We randomly assigned participants to receive 145-mg fenofibrate tablets or placebo (taken daily or, in those with impaired renal function, on alternate days). The primary outcome was a composite of developing referable diabetic retinopathy or maculopathy (based on Scotland’s DES grading scheme) or treatment (intravitreal injection, retinal laser, vitrectomy) for retinopathy or maculopathy.ResultsA total of 1151 participants were randomly assigned to treatment. During a median of 4.0 years, progression to referable diabetic retinopathy or maculopathy, or treatment thereof, occurred in 131 (22.7%) of 576 participants in the fenofibrate group and 168 (29.2%) of 575 in the placebo group (hazard ratio, 0.73; 95% confidence interval [CI], 0.58 to 0.91; P=0.006). In the fenofibrate group compared with the placebo group, the frequencies for any progression of retinopathy or maculopathy were 185 (32.1%) vs. 231 (40.2%); hazard ratio, 0.74; 95% CI, 0.61 to 0.90 and for the development of macular edema were 22 (3.8%) vs. 43 (7.5%); hazard ratio, 0.50; 95% CI, 0.30 to 0.84. Seventeen (3.0%) participants assigned fenofibrate and 28 (4.9%) assigned placebo were given treatment for retinopathy (hazard ratio, 0.58; 95% CI, 0.31 to 1.06). There was no effect on visual function, quality of life, or visual acuity. Trial-averaged estimated glomerular filtration rate was 7.9 (95% CI, 6.8 to 9.1) ml/min/1.73 m2 lower in participants in the fenofibrate group compared with the placebo group. Serious adverse events occurred in 208 (36.1%) participants allocated fenofibrate and 204 (35.5%) participants allocated placebo.ConclusionsFenofibrate reduced progression of diabetic retinopathy compared with placebo among participants with early retinal changes. (Funded by the National Institute for Health and Care Research; ClinicalTrials.gov number, NCT03439345; ISRCTN number, ISRCTN15073006.)

Out with the old, in with the new? The revised AAST grading schema better predicts splenic salvage but not splenectomy

BackgroundThe revised American Association for the Surgery of Trauma (AAST) organ injury scale (OIS) for splenic injury incorporates radiologic features but the implications of this are unknown. We hypothesized that the revised AAST-OIS would better predict outcomes. MethodsPatients with a blunt splenic injury admitted to a Level I trauma center were reviewed from 2016 to 2021. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for splenectomy were calculated for high-grade injuries (AAST-OIS grades IV-V) using both schemas. ResultsOf the 852 patients analyzed, 48.5% were observed, 24.6% were embolized, and the remaining underwent operative intervention. The median AAST-OIS increased from II to III (p ​< ​0.01). Sensitivity (38.0% vs. 73.7%) and NPV (80.9% vs. 88.2%) for splenectomy increased for high-grade injuries but specificity (93.5% vs 70.1%) and PPV (67.5% vs 46.7%) decreased. ConclusionThe revised AAST-OIS better predicted splenic salvage but is less accurate at predicting need for splenectomy.

Auxiliary osseous findings in fetlocks of non-racing sports horses with sagittal groove disease of the proximal phalanx on low-field magnetic resonance imaging.

Sagittal groove disease of the proximal phalanx in equine athletes is commonly considered a bone stress injury. Repetitive hyperextension of the fetlock under high load is thought to contribute to its development. Concurrent changes are often reported in the dorsal sagittal ridge of the third metacarpus/metatarsus (MC3/MT3). To describe the spectrum of associated osseous abnormalities that are present in the fetlock in a large group of horses diagnosed with sagittal groove disease on low-field magnetic resonance imaging (MRI). Retrospective, cross-sectional. MRI images of horses diagnosed with sagittal groove disease at Equitom Equine Clinic between March 2014 and March 2023 were evaluated using semi-quantitative grading schemes and a sagittal groove disease MRI classification system. MRIs of 132 limbs were evaluated, predominantly from warmbloods used for showjumping (n = 83) and dressage (n = 18). Osseous densification and bone oedema-like signal grades were higher in the dorsal sagittal ridge than palmarly/plantarly (p < 0.001 and p < 0.05, respectively). Grades of both osseous densification and bone oedema-like signal in the dorsal sagittal ridge did not significantly differ between the different sagittal groove disease MRI classifications (both p > 0.05). Inclusion based on original MRI reports, absence of control group, small numbers within some grading groups hindering statistical analyses. Findings support the aetiological theories of chronic bone-stress due to loaded fetlock hyperextension however the severity of osseous changes of the dorsal sagittal ridge does not appear to be associated with the severity of sagittal groove disease classification.

Endoscopic Endonasal Internal Carotid Artery Transposition Technique in Tumor With Parasellar Extension: A Single-Center Experience.

Lateralization or mobilization of the internal carotid artery (ICA) during a midline approach is required to expose lesions behind or lateral to the ICA. However, there have been no published data regarding the surgical outcomes of the endoscopic endonasal internal carotid transposition technique (EEITT). This study aimed to analyze the relevant surgical anatomy around the ICA and propose a grading scheme of EEITT. A retrospective review of patients who underwent EEITT at a single institution was performed. Based on structures that limited the ICA and intraoperative findings, an anatomically surgical grading scheme of EEITT was proposed. Forty-two patients (mean age 45.6 years, 57.1% female patients) were included. Of them, 29 cases (69.0%) were Knosp grade 4 pituitary adenoma, 6 cases (14.3%) were chordoma, 6 cases (14.3%) were meningioma, and a single case (2.4%) was meningeal IgG4-related disease. The EEITT was categorized into Grades 1, 2 and 3, which was used in 24 (57.1%), 12 (28.6%), and 6 (14.3%) cases, respectively. The most common symptom was visual disturbance (45.2%). The gross total resection rate in Grade 1 (79.2%) and Grade 2 (83.3%) was much higher than that in Grade 3 (66.6%). The overall rate of visual function improvement, preoperative cranial nerve (CN) palsy improvement, and postoperative hormonal remission was 89.4%, 85.7%, and 88.9%, respectively. The rate for the following morbidities was cerebrospinal fluid leakage, 2.4%; permanent diabetes insipidus, 4.8%; new transient CN palsy, 9.5%; permanent CN palsy, 4.7%; panhypopituitarism, 7.1%; and ICA injury, 2.4%. The EEITT is technically feasible and could be graded according to the extent of disconnection of limiting structures. For complex tumor with parasellar extensions, the distinction into Grades 1, 2, and 3 will be of benefit to clinicians in predicting risks, avoiding complications, and generating tailored individualized surgical strategies.

Clinical characteristics and associated factors of diabetic retinopathy in Sudanese patients

Background: Diabetic retinopathy (DR) is a leading cause of vision loss and preventable blindness, particularly in middle- and high-income countries.Aim: This study aimed to assess the characteristics and associated factors of DR in Sudanese patients with type 2 diabetes mellitus (DM).Setting: A cross-sectional hospital-based study included 119 patients with type 2 DM was conducted at EL-Walidain Eye Hospital, Khartoum, Sudan, from February 2021 to May 2021.Methods: A non-mydriatic digital fundus camera was used for fundus photography, and Scottish Diabetic Retinopathy Grading Scheme was used for the final classification of DR.Results: Females comprised 53.8% of patients, mean age of 58.8 ± 8.5 years. Uncontrolled DM was found in 37.8% with a mean duration of 10.5 ± 4.8 years. Myopia was the most common refractive error found in 57.8% of the uncontrolled group, followed by emmetropia (17.8%). Whereas in the controlled group, 47.3% were hyperopic and 39.2% were myopic. Maculopathy grade M1 was found to be 37.8% in the uncontrolled group and 18.9% in the controlled group, with no significant difference (p = 0.361). Conversely, the difference in retinopathy between the two groups was statistically significant (p = 0.043).Conclusion: Decreased vision and increased retinopathy were associated with an increase in patients’ age. More widespread diabetes awareness and screening programmes to improve diabetes management and control in Sudan and other developing countries.Contribution: This study observed maculopathy grade M1 and myopia were more common in uncontrolled DM, and vision function was inversely correlated with age (p 0.05).

Preparation and Properties of Expansive Backfill Material Based on Municipal Solid Waste Incineration Fly Ash and Coal Gangue

To realize the large-scale utilization of municipal solid waste incineration (MSWI) fly ash in the field of building materials and to reduce the cost of coal mine backfill mining, the effects of the mixing ratio of cementitious materials, the particle size distribution of aggregates, and the amount and mass concentration of cementitious materials on the properties of backfill materials were experimentally investigated, and the microstructure of the hydration products was analyzed. The results showed that as the mass ratio of MSWI fly ash to bottom ash increased, the rate of expansion of the cementitious system continued to increase, and the compressive strength of the cementitious system continued to decrease. The Al (aluminum) and AlN (aluminum nitride) in the fly ash reacted with water to generate gas, causing the expansion of the cementitious materials; NaOH increased the alkalinity of the solution, which promoted the formation of more bubbles, thereby improving the expansion performance of the cementitious material. When the content of NaOH was 0.9%, the sample rate of expansion could reach 15.9%. The addition of CaCl2 promoted the early hydration reaction of the cementitious material, forming a dense microstructure, thus improving the early strength and rate of expansion of the cementitious material. The compressive strength of the backfill body increased as the fractal dimension of the aggregate particles increased, and the particle grading scheme of group S1 was optimal. The 1-day, 3-day, and 28-day strengths of the backfill body of group S1 reached 0.72 MPa, 1.43 MPa, and 3.26 MPa, respectively. It is recommended to choose a backfill paste concentration ranging between 78.5% and 80% and a reasonable amount of cementitious material between 20% and 25%. After the MSWI fly ash was prepared as a backfill material, the leaching of potentially harmful elements in the fly ash was greatly reduced, and the concentration of dioxin was reduced to 13 ng TEQ/kg. This was attributed to the dilution of the cement, the physical encapsulation of gel products, and the isomorphous replacement of Ca2+ in calcium aluminate chloride hydrate.

Cross-modality transfer learning with knowledge infusion for diabetic retinopathy grading.

Ultra-wide-field (UWF) fundus photography represents an emerging retinal imaging technique offering a broader field of view, thus enhancing its utility in screening and diagnosing various eye diseases, notably diabetic retinopathy (DR). However, the application of computer-aided diagnosis for DR using UWF images confronts two major challenges. The first challenge arises from the limited availability of labeled UWF data, making it daunting to train diagnostic models due to the high cost associated with manual annotation of medical images. Secondly, existing models' performance requires enhancement due to the absence of prior knowledge to guide the learning process. By leveraging extensively annotated datasets within the field, which encompass large-scale, high-quality color fundus image datasets annotated at either image-level or pixel-level, our objective is to transfer knowledge from these datasets to our target domain through unsupervised domain adaptation. Our approach presents a robust model for assessing the severity of diabetic retinopathy (DR) by leveraging unsupervised lesion-aware domain adaptation in ultra-wide-field (UWF) images. Furthermore, to harness the wealth of detailed annotations in publicly available color fundus image datasets, we integrate an adversarial lesion map generator. This generator supplements the grading model by incorporating auxiliary lesion information, drawing inspiration from the clinical methodology of evaluating DR severity by identifying and quantifying associated lesions. We conducted both quantitative and qualitative evaluations of our proposed method. In particular, among the six representative DR grading methods, our approach achieved an accuracy (ACC) of 68.18% and a precision (pre) of 67.43%. Additionally, we conducted extensive experiments in ablation studies to validate the effectiveness of each component of our proposed method. In conclusion, our method not only improves the accuracy of DR grading, but also enhances the interpretability of the results, providing clinicians with a reliable DR grading scheme.

Five Evidence-Based Strategies to Foster a Culture of Well-Being in Physician Assistant Education.

The objective of this study was to discuss evidence-based strategies to promote a culture of well-being with physician assistant (PA) education. Published literature on medical student, resident, and PA student well-being was reviewed with findings subsequently categorized according to well-being strategy. Five themes were found from existing well-being research within medical student and PA student education: faculty role modeling and support, dedicated curricular time, pass/fail grading schema and de-emphasizing grades, peer support and learning communities, and evaluation importance. Physician assistant educators may be able to foster a culture of well-being for their students by making even small adjustments to the existing educational curriculum.

TO EXPLORE THE CLINICAL FRAILTY SCALE IN PREDICTING THE LONG TERM PROGNOSIS OF PATIENTS WITH ACUTE MYOCARDIAL INFARCTION AFTER IN-HOSPITAL CARDIAC REHABILITATION

Objective: Patients successfully revascularized after acute myocardial infarction (AMI) underwent in-hospital cardiac rehabilitation (CR) and were assessed for their state by the clinical frailty scale (CFS) to investigate the predictive value of the CFS score on the incidence rate of major cardiovascular events within one year. Design and method: A graded CR scheme was developed in a total of 501 patients with AMI, who were treated in the cardiology center of Shanghai Sixth People’s Hospital from May 2020 to May 2022, and the CFS score was assessed based on the CR condition of the patients before discharge. Patients were then categorized into three groups (norm group, vulnerable group, and frail group) according to their CFS score. The difference in one-year major cardiovascular event (all-cause death and re-hospitalization for heart failure) rates among these groups was compared. Logistic regression analysis was performed to explore risk factors affecting cardiovascular events, and an ROC curve was generated to analyze the risk factors in predicting one-year cardiovascular event rates. Finally, an optimal prediction model was developed. Results: The CFS score in AMI patients was positively correlated with age and peak proBNP and inversely correlated with gender difference (P &lt;= 0.001). There were significant differences in the incidence of all-cause death between the frail group and the norm group (P = 0.002), whereas there was no significant difference between the vulnerable group and the norm group (P &gt; 0.05). There was no significant difference in re-hospitalization for heart failure among the three groups (P = 0.710). The CFS score could sensitively predict the 1-year risk of all-cause death in AMI patients (β = 1.89, OR = 6.61, P = 0.001), and the risk model combined with the CFS score had the best predictive effect (AUC = 0.845, P = 0.000). Conclusions: In-hospital CR along with assessment using the CFS score can effectively identify AMI patients with a high risk of death.

Labor-based grading practices in the physics classroom

I describe the assessment framework of labor-based contract grading (LBCG). In a labor-based grading scheme, the time and effort (“labor”) a student spends on an assignment determines the credit they receive; the contract component requires students to design projects with clearly defined goals and deliverables, which must be satisfied to earn credit. LBCG is intended to promote student agency and engagement and to provide a more equitable assessment framework, given that students come with a wide range of prior experiences and preparation. I illustrate the LBCG framework within the context of an upper level physics course, using a particular assignment as an example; I also provide information on student experiences and engagement.

OA29 Epigenetic regulation of IL-4 promoter targeting p300 attenuating intervertebral disc degeneration and pain by inhibiting IL-1β

Abstract Background/Aims Low back pain (LBP) is a prevalent condition primarily caused by intervertebral disc degeneration (IVDD), which imposes a substantial social and medical burden. Effective targeted treatments to prevent the progression of IVDD and alleviate LBP are still lacking. p300, a critical member of the histone acetyltransferase (HAT) family, is involved in the regulation of inflammation. This study aims to investigate the role of p300/IL-4 in IVDD and pain and elucidate the underlying molecular mechanism. Methods Human intervertebral disc samples were collected and graded based on the Pfirrmann grading scheme. A rat model of IVDD was established through posterior disc puncture, and various treatments were administered. Human nucleus pulposus cells (NPCs) were isolated and cultured, followed by assessments including qRT-PCR, Western blotting, immunofluorescence, and histopathological analyses. The mechanical and thermal hyperalgesia were assessed using von Frey hair tests and the plantar test, respectively. Chromatin immunoprecipitation (ChIP) and ChIP-qPCR were performed, and lentivirus transduction was used for p300 knockdown. Results We investigated the role of CREB binding protein (CBP)/p300 in IVDD. Degenerated nucleus pulposus (NP) tissues from IVDD patients exhibited a significant downregulation of p300 at both nucleic acid and protein levels, while CBP levels remained unchanged. Manipulating p300 expression in NPCs regulated matrix production, with p300 overexpression enhancing aggrecan and collagen II expression and knockdown leading to increased matrix-degrading proteins. In a rat IVDD model, activating p300 function with CTPB (p300-specific activator) alleviated IVDD and pain, while inhibiting p300 with C646 exacerbated IVDD and pain. Transcriptome analysis implicated IL-4 as a downstream effector of p300, and IL-4 demonstrated protective effects against IVDD and pain. Mechanistically, p300 was found to acetylate H3K27 at the IL-4 promoter, promoting its expression. Conclusion The novel findings of this study suggest that the p300/IL-4/IL-1β axis may represent a promising therapeutic target for IVDD and LBP. These results propose a hypothesis that, early in the inflammatory phase, NPCs may initiate a self-protective mechanism through p300, aiding itself in preserving a favourable metabolic microenvironment. This mechanism is primarily mediated by the expression of IL-4, which has the capacity to counteract IL-1β, rather than TNF-α. Disclosure H. Cui: None. Z. Zheng: None.

What topics of peer interactions correlate with student performance in physics courses?

Research suggests that interacting with more peers about physics course material is correlated with higher student performance. Some studies, however, have demonstrated that different topics of peer interactions may correlate with their performance in different ways, or possibly not at all. In this study, we probe both the peers with whom students interact about their physics course and the particular aspects of the course material about which they interacted in six different introductory physics courses: four lecture courses and two lab courses. Drawing on social network analysis methods, we replicate prior work demonstrating that, on average, students who interact with more peers in their physics courses have higher final course grades. Expanding on this result, we find that students discuss a wide range of aspects of course material with their peers: concepts, small-group work, assessments, lecture, and homework. We observe that in the lecture courses, interacting with peers about concepts is most strongly correlated with final course grade, with smaller correlations also arising for small-group work and homework. In the lab courses, on the other hand, small-group work is the only interaction topic that significantly correlates with final course grade. We use these findings to discuss how course structures (e.g. grading schemes and weekly course schedules) may shape student interactions and add nuance to prior work by identifying how specific types of student interactions are associated (or not) with performance.

Rectal Spacer Reduces Gastrointestinal Side Effects of Radiation Post Radical Prostatectomy

Objectives: Our objective was to assess the rate of complications and gastrointestinal adverse effects of rectal spacer insertion for salvage post prostatectomy radiation therapy. Methods: A retrospective observational study was performed. Between September 2018 and March 2022, 64 post-radical prostatectomy patients who were planned for salvage radiation therapy received a rectal spacer. The selected patients were those who had nerve-sparing prostatectomy with intrafascial or interfascial dissections (where Denonvillier’s fascia is retained). Radiation dose to the rectal wall and gastrointestinal symptoms were assessed. Symptoms were graded using the National Cancer Center Institute Common Terminology Criteria for Adverse Events v4.0 grading scheme. A total of 39 patients had pre-spacer planning computer tomography (CT) scans, and the rectal dose before and after the spacer insertion was calculated. Comparisons were made using the Student’s t-test, with a p-value &lt; 0.05 representing statistical significance. Finally, clinicians were surveyed to rate the ease of the procedure using a 5-point Likert scale of 1 to 5 (1: very difficult, 2: difficult, 3: moderate, 4: easy, 5: very easy). Results: A total of 64 patients successfully underwent rectal spacer insertion. The mean age was 64.4 years (standard deviation: 5.7 years). After a median of 14 months’ (range 6 to 35) follow up, acute grade 1 and above gastrointestinal (GI) toxicities were seen in 28% of patients (grade 2 in 1.5%), and late grade 1 and above GI toxicities were seen in 12% of patients (grade 2 in 1.5%). Amongst the 39 patients with pre-spacer planning CT images, the volume of the rectum receiving 60%, 70%, 80%, 90%, and 100% of the prescribed radiation dose was reduced by 25.9%, 34.2%, 35.4%, 43.7%, and 61.7%, respectively. All dose reductions were statistically significant. The procedure was rated as “easy” or “very easy” to perform in 56% of cases. Conclusions: The insertion of a rectal spacer in selected patients undergoing PPRT is feasible and safe and significantly improves rectal wall radiation dosimetry in salvage post prostatectomy radiation therapy. It was accomplished in &gt;95% of patients, increasing vesico-rectal separation from ‘immediate vicinity’ to 11 mm without any post-operative complications in experienced hands. In addition, it achieved significant reduction in rectal radiation doses, leading to low rates of acute and late grade 2 toxicity.

Novel 3D MRI-based volumetric assessment of rotator cuff musculature demonstrates stronger correlation with preoperative functional status when compared to the Goutallier grading scheme

The Goutallier classification (GC) is used to assess fatty atrophy in rotator cuff (RC) tears, yet limitations exist. A battery of 3-dimensional (3D) magnetic resonance imaging (MRI) volumetric scores (VSs) was developed to provide comprehensive characterization of RC pathology. The purposes of this study were to (1) describe the correlation between GC and VSs for supraspinatus changes in RC tears, (2) characterize the chronicity of RC tears using a battery of 12 VS measurements, and (3) compare GC and VSs to determine which method most closely corresponds with preoperative patient-reported outcome measures (PROMs). Preoperative shoulder MRIs were reviewed after arthroscopic RC repair. Preoperative GC stage and Patient-Reported Outcomes Measurement Information System (PROMIS) physical function (PF) and pain interference (PI) scores were collected. The battery of VSs included fat infiltration (FIS), muscle size (MSS), and relative volume contribution (RCS) for each RC muscle. Backward linear regression was performed to compare GC stage with preoperative PROMIS PF and PI to determine which VS measurement most closely correlated with preoperative PROMs. Eighty-two patients underwent RC repair (mean age 55±8.2 years, 63% male, 68% GC stage ≤1). In evaluation of the supraspinatus, there was a moderate positive correlation between GC and FIS (r=0.459, P<.001); strong negative correlations were observed between MSS (r=-0.800, P<.001) and RCS (r=-0.745, P<.001) when compared to GC. A negligible linear correlation was observed between GC and preoperative PROMIS PF (r=-0.106, P=.343) and PI (r=-0.071, P=.528). On multivariate analysis, subscapularis MSS (β >0, P=.064) was a positive predictor and subscapularis FIS (β <0, P=.137), teres minor MSS (β <0, P=.141), and FIS (β <0, P=.070) were negative predictors of preoperative PF (r=0.343, P=.044); in contrast, supraspinatus MSS (β >0, P=.009) and FIS (β >0, P=.073), teres minor FIS (β >0, P=.072), and subscapularis FIS (β >0, P=.065) were positive predictors of preoperative PI (r=0.410, P=.006). Although the criterion standard in evaluation of RC pathology, GC demonstrated negligible correlation with preoperative functional disability. Alternatively, a battery of 3D VSs showed strong correlation with GC through a quantitative, comprehensive evaluation of the RC unit including several moderate predictors of preoperative functional disability.

Use of specifications-based grading in an online, asynchronous graduate organic chemistry course

Specifications-based grading is an alternative grading scheme that emphasizes student proficiency of learning objectives. Course grades are determined by the number of objectives completed rather than the number of points accumulated. At the University of Saint Joseph, CHEM 510 Intermediate Organic Chemistry is the foundation course that all incoming graduate students take in their first semester of the fully online, asynchronous MS programs in Chemistry and Biochemistry. Students in CHEM 510 complete the entire course online and at their own pace within the structured due dates, which presents unique challenges compared with synchronous learning modalities. With these considerations in mind, CHEM 510 was revised to use a specifications-based grading scheme with an a la carte assessment menu and token system. Generally, students found the alternative grading scheme helpful, but they needed additional instructions and time to adjust to the new grading system. By the end of the semester, students expressed their appreciation for the ability to choose their assessment method, work at their own pace, and use the token system for extensions/retakes. The instructor found that implementation of specifications grading took greater time for the initial course setup, but did not require more time than points-based grading once the course began. One large positive outcome was that student-instructor interactions were more frequently about the content of the course rather than grades. Overall, there was a slight increase in the course’s pass rate compared to the pass rate prior to the change in grading modality. We believe that the implementation of the a la carte assessment menu accommodates a more diverse population of learners without sacrificing the integrity of student learning. Additionally, we believe that the diverse assessment opportunities were critical for the successful implementation of specifications-based learning in the online classroom environment, though further extension of the menu in synchronous, in-person classroom settings may be challenging.

Low-field magnetic resonance imaging of sagittal groove disease of the proximal phalanx in non-racing sport horses.

Injuries of the sagittal groove of the proximal phalanx (P1) in equine athletes are considered to predominantly occur due to chronic bone stress overload. To describe the range of abnormalities that is present in the sagittal groove in a large group of horses diagnosed with sagittal groove disease (SGD) on low-field MRI. Retrospective, cross-sectional. Medical records were searched to identify initial MRI images of horses diagnosed with SGD and these were blindly evaluated using a semi-quantitative grading scheme and novel SGD MRI classification system reflecting potential pathways of pathological progression and severity of stress injury. A total of 132 limbs from 111 horses were included in the study; predominantly warmbloods competing in showjumping (n = 83) and dressage (n = 18). SGD MRI classifications were: 0 (normal, n = 0), 1 (small subchondral defect, n = 2), 2 (osseous densification, n = 28), 3 (subchondral microfissure with osseous densification, n = 7), 4 (bone oedema-like signal within the subchondral ± trabecular bone and ± subchondral microfissure or demineralisation, n = 72), 5 (incomplete macrofissure/fracture, n = 23) and 6 (complete fracture, n = 0). Classification 4c (bone oedema-like signal with demineralisation) and 5 had higher proportions in the plantar third of hindlimbs (3% and 10%, respectively) compared with forelimbs (0% and 0%, respectively). SGD classification and extent of bone oedema-like signal were not significantly different between lame (n = 116) and non-lame limbs (n = 16) (both p > 0.05). Periosteal new bone and oedema-like signal were identified (either confidently or suspected) at the dorsoproximal aspect of P1 in 25% and 39% of limbs, respectively. Inclusion via diagnoses in original MRI reports, variable clinical history, small size of some classification groups. The presence or absence of lameness is not a dependable measure of the severity of SGD. The periosteal oedema-like signal of P1 has not previously been described in MRI of SGD and further supports the concept of bone stress injury.

380 2021 WHO Grading Scheme Provides Minimal Incremental Improvement in Prognostic Stratification of a Retrospective IDH-Mutant Astrocytoma Cohort Compared to 2016 WHO Grading Scheme

INTRODUCTION: The 2021 WHO Classification of CNS Tumors introduced prognostically relevant molecular alterations (ex. CDKN2A homozygous deletion) into grading criteria for select tumors. METHODS: We retrospectively identified 176 adult IDHmAstro patients with available next-generation sequencing (NGS). All tumors were regraded based on the 2021 and 2016 WHO grading schema using relevant histopathological (mitotic rate, microvascular proliferation, necrosis) and molecular (CDKN2A) features. The prognostic ability of each grading schema was evaluated with Kaplan-Meier and multivariate Cox Regression analyses. RESULTS: The cohort consisted of 76 grade 2 (43.2%), 45 grade 3 (25.6%), and 55 grade 4 (31.3%) IDHmAstro cases using the 2021 grading schema. Only four patients (2%) had a grade change from the 2016 WHO grading scheme - one prior 2016 WHO grade II and three grade III tumors, all regraded to Grade 4 based on present CDKN2A homozygous deletion. When assessed based on both classification schemas, WHO Grade 4/IV tumors were associated with lower OS than Grade 2/II tumors (HR [95% CI]: 4.20 [1.09–16.22], P = 0.037 per 2016 and 3.82 [1.04–14.09], P = 0.044 per 2021). There were no significant differences in OS between Grade 2/II and Grade 3/III tumors or Grade 3/III and Grade 4/IV tumors within either grading schema. CONCLUSIONS: Only four patients had a change in grade, implying the majority of IDHmAstro patients would have received similar treatment using either grading schema. Interestingly, outcomes for grade 3/III IDHmAstro were not significantly different from grade 2/II or grade 4/IV IDHmAstro in either schema, suggesting that grade 3/III tumors represent a biologically heterogeneous group. These results should be validated in other series but underscore a continued unmet need for novel biomarkers to improve IDHmAstro risk-stratification.

Rigid-Elastic Combined Metamaterial Beam With Tunable Band Gaps for Broadband Vibration Suppression

Abstract Extensive research efforts have been dedicated to exploring the application of metamaterial beams for vibration suppression. However, most existing designs primarily focused on utilizing the translational motion of local resonators to create band gaps. To address this limitation of employing solo motion to induce a relatively narrow band gap, this study proposes a novel design: a rigid-elastic combined metamaterial beam utilizing both translational and rotational motions of local resonators. Theoretical framework development involves extending the transfer matrix method to incorporate rigid bodies, with analytical results validated through finite element simulations and experimental data. Compared to conventional metamaterial beams, the proposed design exhibits an additional wide band gap in the low-frequency region that can be utilized for broadband vibration suppression. A parametric study elucidates the influences of geometric parameters on band gap formation, followed by an exploration of the tunability of the proposed meta-beam through a graded scheme and optimization strategy. In particular, a multiple-objective optimization approach is employed to enlarge the vibration suppression region and enhance vibration suppression ability. The optimized meta-beam demonstrates a remarkable 45% wider dominant suppression region and a 14% lower average transmittance compared to a uniform model.

Energy absorption and mechanical response of Graded face-centered cubic structures

Enhancing the energy absorption capability of lightweight structures, through the use of functionally-graded materials, has recently attracted attention. The thickness grading method of plate lattices in the literature is limited to a discrete layer-by-layer grading, as the thickness in any single layer is uniform but different from the thickness of the other layers. The sudden changes between the layers result in a stress concentration. A continuous thickness grading is achieved in this study, and the effect of employing distinct grading schemes applied to FCC structures has been investigated. Axial continuous thickness grading, lateral continuous thickness grading, and an axial-lateral hybrid continuous thickness grading are examined, alongside discrete layer-by-layer unit cell size grading. Manufactured from Nylon using the material extrusion additive manufacturing method, the samples were benchmarked against uniform structures. To further understand the behavior of these structures, a numerical study, via Abaqus models of the quasi-static compression test, was undertaken and the resulting predictions offered good agreement with the experimental data. The axial thickness grading exhibits significant potential, resulting in a substantial increase of up to 39 % in specific energy absorption due to the layer-by-layer deformation, compared to their uniform counterparts. In contrast, unit cell size grading compromises the energy absorption efficiency, while improving the crushing force efficiency by 35 %. A higher mean crushing force up to 8 % was achieved by the lateral grading method. This investigation highlights the effect of adopting distinct grading approaches on both energy absorption and mechanical response, yielding useful information for the design of advanced protective systems.

Attachment Loss Attributable to Third Molar Malposition/Extraction: The Case for Classification

Background: The 2017 World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions established a periodontitis staging and grading scheme that—for the first time—integrates an assessment of disease severity with an appraisal of therapeutic complexity and risk for disease progression. Individuals exhibiting attachment loss attributable to third molar malposition or extraction represent a large cohort of non-periodontitis patients highly likely to respond favorably to treatment. The purpose of this clinical report is to illustrate the value in formally categorizing this common periodontal condition. Case Description: Two male patients were referred to the Department of Periodontics, Army Postgraduate Dental School, for evaluation of bone and attachment loss limited to distal surfaces of mandibular second molars. Each patient was treated using a combination of guided tissue regeneration and bone replacement grafts. Favorable clinical and radiographic outcomes were observed over follow-up periods ranging from 4 months to 4 years. Practical Implications: Many patients experiencing bone and attachment loss attributable to third molar malposition or extraction lack periodontitis risk factors/indicators, have low susceptibility to the disease, and are highly likely to respond favorably to treatment. Future classification systems of periodontal diseases and conditions should formally categorize this commonly encountered periodontal condition.