Analysis of different surgical approaches to the treatment of thymoma.

BACKGROUND: Surgical approach in the treatment of thymoma is varied. This retrospective study aimed to evaluate the outcomes of different surgical approaches in the treatment of thymoma. METHODS: From January 2020 to December 2023, a total of 208 patients underwent thoracoscopic surgical treatment and were diagnosed with thymoma by postoperative pathological result in our institution. We collected and then analysed potential factors including general conditions, surgical approaches, preoperative clinical symptoms, surgical procedures, postoperative hospital stay, postoperative drainge, postoperative pain score, postoperative complications and postoperative follow-up. RESULTS: Of the 208 patients, 98 patients underwent surgery via subxiphoid approach (47.1%) and 110 patients via lateral intercostal approach (52.8%). The duration of the surgical procedure (P = 0.02), intraoperative blood loss (P = 0.045), total postoperative drainage (P = 0.021), postoperative drainage per day (P = 0.004) and Postoperative pain score (Day1 P = 0.010 and Day2 P = 0.002)showed a significant difference between these two groups. 31 patients (14.9%) received postoperative radiotherapy. One patient died due to postoperative radiotherapy. No recurrence occurred in one-year follow-up. CONCLUSIONS: The present study not only showed that subxiphoid approach was a safe and feasible technique for thymoma, with a potentially faster postoperative recovery and less postoperative pain.

Dosage constraint of the ribosome-associated molecular chaperone drives the evolution and fates of its duplicates in bacteria.

Gene duplication events happen prevalently during evolution, and the mechanisms governing the loss or retention of duplicated genes are mostly elusive. Our genome scanning analysis revealed that trigger factor (TF), the one and only bacterial ribosome-associated molecular chaperone, is singly copied in virtually every bacterium except for a very few that possess two or more copies. However, even in these exceptions, only one complete TF copy exists, while other homologs lack the N-terminal domain that contains the conserved ribosome binding site (RBS) motif. Consistently, we demonstrated that the overproduction of the N-terminal complete TF proteins is detrimental to the cell, which can be rescued by removing the N-terminal domain. Our findings also indicated that TF overproduction leads to a decrease in protein productivity and profile changes in proteome due to its characteristic ribosome binding and holdase activities. Additionally, these N-terminal deficient TF homologs in bacteria with multiple TF homologs partition the function of TF via subfunctionalization. Our results revealed that TF is subjected to a dosage constraint that originates from its own intrinsic functions, which may drive the evolution and fates of duplicated TFs in bacteria. IMPORTANCE: Gene duplication events presumably occur in tig, which encodes the ribosome-associated molecular chaperone trigger factor (TF). However, TF is singly copied in virtually every bacterium, and these exceptions with multiple TF homologs always retain only one complete copy while other homologs lack the N-terminal domain. Here, we reveal the manner and mechanism underlying the evolution and fates of TF duplicates in bacteria. We discovered that the mutation-to-loss or retention-to-sub/neofunctionalization of TF duplicates is associated with the dosage constraint of N-terminal complete TF. The dosage constraint of TF is attributed to its characteristic ribosome binding and substrate-holding activities, causing a decrease in protein productivity and profile changes in cellular proteome.

Positivity and Boundedness Preserving Numerical Scheme for a Stochastic Multigroup Susceptible-Infected-Recovering Epidemic Model with Age Structure.

Since the stochastic age-structured multigroup susceptible-infected-recovering (SIR) epidemic model is nonlinear, the solution of this model is hard to be explicitly represented. It is necessary to construct effective numerical methods so as to predict the number of infections. In addition, the stochastic age-structured multigroup SIR model has features of positivity and boundedness of the solution. Therefore, in this article, in order to ensure that the numerical and analytical solutions must have the same properties, by modifying the classical Euler-Maruyama (EM) scheme, we generate a positivity and boundedness preserving EM (PBPEM) method on temporal space for stochastic age-structured multigroup SIR model, which is proved to have a strong convergence to the true solution over finite time intervals. Moreover, by combining the standard finite element method and the PBPEM method, we propose a full-discrete scheme to show the numerical solutions, as well as analyze the error estimations. Finally, the full-discrete scheme is applied to a general stochastic two-group SIR model and the Chlamydia epidemic model, which shows the superiority of the numerical method.

Realizing Stable Luminescence in Antimony Doped Hybrid Tin(IV) Chloride toward Full Spectrum WLED and Anticounterfeiting Applications.

The outstanding optical properties empower Sb3+-doped zero-dimensional hybrid metal halides as cutting-edge luminescent materials. In this research, we present an efficient hybrid tin chloride, TEA2SnCl6:Sb3+ (TEA = tetraethylammonium), with broad dual emission bands peaking in the blue and orange regions that arise from the singlet and triplet state emissions of [SbCl5]2-, respectively. TEA2SnCl6:Sb3+ demonstrates a high photoluminescence quantum yield (PLQY) of 83.5% under 328 nm excitation, while 358 nm light induces an orange emission with a PLQY of 92.5% and a low thermal quenching behavior (73.9% at 423 K). Benefiting from the appealing luminescence properties of TEA2SnCl6:Sb3+, a full spectrum white light-emitting diode (WLED) device and an anticounterfeiting model were constructed, affirming the potential use of Sb3+-doped TEA2SnCl6 hybrid metal halide in versatile application fields.

Platelet-Rich Plasma Injection Combined With Q-Switched Ruby Laser in the Treatment of Periorbital Hyperpigmentation.

BACKGROUND: Periorbital hyperpigmentation is a prevalent skin condition that represents a large quantity of cases seen in cosmetic dermatology. Patients tend to be left with pigmentation after Q-switched ruby laser treatment, especially the perioribital area. AIMS: The study is conducted to compare the effect of PRP injection combined with laser therapy versus laser alone for periorbital hyperpigmentation treatment. PATIENTS/METHODS: In this single-center, case-control study, 30 patients with periorbital hyperpigmentation were allocated to receive PRP injection injection after Q-switched ruby laser or Q-switched ruby laser only, followed by a 12-week and 24-week follow-up visit. Visual analogue scale, Sadick tear trough rating scale, and patients' self-evaluation were used to evaluate the therapeutic effect. RESULTS: The combined group achieved a better improvement in long-term effect and had effect on facial rejuvenation. Patient satisfaction was higher in the combined group. Erythema and mild pain were the most common adverse reactions of both groups. CONCLUSIONS: Combining with PRP injection can improve the therapeutic effect of Q-switched ruby laser in treating periorbital hyperpigmentation and lessen the risk of post-inflammatory hyperpigmentation, indicating a new option for POH treatment.

Reclaiming the Lost Conformality in a Non-Hermitian Quantum 5-State Potts Model.

Conformal symmetry, emerging at critical points, can be lost when renormalization group fixed points collide. Recently, it was proposed that after collisions, real fixed points transition into the complex plane, becoming complex fixed points described by complex conformal field theories (CFTs). Although this idea is compelling, directly demonstrating such complex conformal fixed points in microscopic models remains highly demanding. Furthermore, these concrete models are instrumental in unraveling the mysteries of complex CFTs and illuminating a variety of intriguing physical problems, including weakly first-order transitions in statistical mechanics and the conformal window of gauge theories. In this work, we have successfully addressed this complex challenge for the (1+1)-dimensional quantum 5-state Potts model, whose phase transition has long been known to be weakly first order. By adding an additional non-Hermitian interaction, we successfully identify two conjugate critical points located in the complex parameter space, where the lost conformality is restored in a complex manner. Specifically, we unambiguously demonstrate the radial quantization of the complex CFTs and compute the operator spectrum, as well as new operator product expansion coefficients that were previously unknown.

Prediction of Prognosis and Response to Androgen Deprivation Therapy in Intermediate to High-Risk Prostate Cancer Using 18F-FDG PET/CT Radiomics.

RATIONALE AND OBJECTIVES: This study aims to predict intermediate to high-risk prostate cancer (PCa) prognosis based on 18-fluoro-2-deoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) radiomics. Additionally, subgroup analysis will be performed on the androgen deprivation therapy (ADT) group and the metastatic PCa group. MATERIALS AND METHODS: In the retrospective analysis of 104 intermediate to high-risk PCa patients who underwent 18F-FDG PET/CT prior to treatment. The data set was divided into a training set (n = 72) and a testing set (n = 32). Two different PET/CT models were constructed using multivariate logistic regression with cross-validation: radiomics model A and an alternative ensemble learning-based model B. The superior model was then selected to develop a radiomics nomogram. Separate models were also developed for the ADT and metastatic PCa subgroups. RESULTS: Model A, which integrates eight radiomics features showed excellent performance with an area under curve (AUC) of 0.844 in the training set and 0.804 in the testing set. The radiomics nomogram incorporating the radiomics score (radscore) from model A and the tumor-to-liver ratio (TLR) showed good prognostic accuracy in the testing set with an AUC of 0.827. In the subgroup analyses for endocrine therapy and metastatic cancer, the PET/CT radiomics model showed AUCs of 0.845 and 0.807 respectively, suggesting its potential effectiveness. CONCLUSION: The study establishes the utility of the 18F-FDG PET/CT radiomics nomogram in predicting the prognosis of intermediate to high-risk PCa patients, indicating its potential for clinical application.

Progression of cognitive impairment in Parkinson's disease correlates with uric acid concentration.

Introduction: This study assessed the relationship between the progression of Parkinson's disease (PD) with cognitive impairment and changes in serum uric acid (UA) and homocysteine (Hcy) concentrations and explored the factors influencing PD with cognitive impairment. Methods: The study randomly selected 74 patients with PD and evaluated their cognitive function using the Montreal Cognitive Assessment Scale (MoCA). Patients with PD were divided into two subgroups: those with and without cognitive impairment. PD severity was evaluated and graded using the Hoehn and Yahr (H-Y) scale. Another 60 middle-aged and older individuals without PD during the same period were selected as a control group. Blood UA and Hcy concentrations in each group were measured to assess the relationship between PD, cognitive impairment, and changes in UA and Hcy concentrations. Results: The PD group with cognitive impairment had a lower UA concentration and higher Hcy concentration. The UA concentration was significantly higher in the early PD stages than in the middle and late stages (P<0.05). A significant negative relationship between MoCA scores and serum UA levels was found in patients with PD, whereas a positive relationship existed between MoCA scores and serum Hcy concentrations. Regression analysis showed that a higher UA concentration was an independent protective factor for PD with cognitive impairment, while a higher Hcy concentration was a risk factor (P<0.05). A serum UA concentration of 212.9 mmol/L and Hcy concentration of 13.35 mmol/L could distinguish between patients with PD with or without cognitive impairment with a sensitivity of 93.2% and specificity of 43.3%. Conclusion: PD and cognitive impairment were associated with a decrease in UA concentration; the later the H-Y stage was, the lower the UA concentration was. The increase in Hcy concentration was related to PD and its cognitive impairment, whereas it is not significantly correlated with PD progression.

Insights into the response of electroactive biofilm with petroleum hydrocarbons degradation ability to quorum sensing signals.

Bioelectrochemical technologies based on electroactive biofilms (EAB) are promising for petroleum hydrocarbons (PHs) remediation as anode can serve as inexhaustible electron acceptor. However, the toxicity of PHs might inhibit the formation and function of EABs. Quorum sensing (QS) is ideal for boosting the performance of EABs, but its potential effects on reshaping microbial composition of EABs in treating PHs are poorly understood. Herein, two AHL signals, C4-HSL and C12-HSL, were employed to promote EABs for PHs degradation. The start-times of AHL-mediated EABs decreased by 18-26%, and maximum current densities increased by 28-63%. Meanwhile, the removal of total PHs increased to over 90%. AHLs facilitate thicker and more compact biofilm as well as higher viability. AHLs enhanced the electroactivity and direct electron transfer capability. The total abundance of PH-degrading bacteria increased from 52.05% to 75.33% and 72.02%, and the proportion of electroactive bacteria increased from 26.14% to 62.72% and 63.30% for MFC-C4 and MFC-C12. Microbial networks became more complex, aggregated, and stable with addition of AHLs. Furthermore, AHL-stimulated EABs showed higher abundance of genes related to PHs degradation. This work advanced our understanding of AHL-mediated QS in maintaining the stable function of microbial communities in the biodegradation process of petroleum hydrocarbons.

Cardiovascular events reported in patients with B-cell malignancies treated with zanubrutinib.

ABSTRACT: First-generation Bruton tyrosine kinase (BTK) inhibitor, ibrutinib, has been associated with an increased risk of cardiovascular toxicities. Zanubrutinib is a more selective, next-generation BTK inhibitor. In this analysis, incidence rates of atrial fibrillation, symptomatic (grade ≥2) ventricular arrhythmia, and hypertension were evaluated in a pooled analysis of 10 clinical studies with zanubrutinib monotherapy in patients (N = 1550) with B-cell malignancies and a pooled analysis of head-to-head studies comparing zanubrutinib with ibrutinib (ASPEN cohort 1; ALPINE). Among the 10 studies, most patients (median age, 67 years) were male (66.3%) and had CLL/SLL (60.5%). Overall incidence and exposure-adjusted incidence rates (EAIR) for atrial fibrillation, symptomatic ventricular arrhythmia, and hypertension were lower with zanubrutinib than ibrutinib. Despite a similar prevalence of preexisting cardiovascular events in ASPEN and ALPINE, atrial fibrillation/flutter incidence rates (6.1% vs 15.6%) and EAIR (0.2 vs 0.64 persons per 100 person-months; P < .0001) were lower with zanubrutinib than with ibrutinib. Symptomatic ventricular arrhythmia incidence was low for both zanubrutinib (0.7%) and ibrutinib (1.7%) with numerically lower EAIR (0.02 vs 0.06 persons per 100 person-months, respectively) for zanubrutinib. The hypertension EAIR was lower with zanubrutinib than ibrutinib in ASPEN but similar between treatment arms in ALPINE. The higher hypertension EAIR in ALPINE was inconsistent with other zanubrutinib studies. However, fewer discontinuations (1 vs 14) and deaths (0 vs 6) due to cardiac disorders occurred with zanubrutinib versus ibrutinib in ALPINE. These data support zanubrutinib as a treatment option with improved cardiovascular tolerability compared with ibrutinib for patients with B-cell malignancies in need of BTK inhibitors. These trials were registered at www.ClinicalTrials.gov as # NCT03053440, NCT03336333, NCT03734016, NCT04170283, NCT03206918, NCT03206970, NCT03332173, NCT03846427, NCT02343120, and NCT03189524.

Effectiveness of Ixekizumab in Chinese Patients with Moderate-Severe Plaque Psoriasis with Special Area Involvement: Subanalysis of a Prospective, Multicenter, Observational Real-World Study.

INTRODUCTION: Ixekizumab, a monoclonal antibody against interleukin-17A, demonstrated effectiveness in the treatment of psoriasis in a Chinese real-world study that was consistent with previous randomized controlled trials. Here, we report further analyses from this study to explore the effectiveness of ixekizumab for treating patients with psoriasis and the involvement of special body areas (scalp, nail, joint, palmoplantar, or genital areas). METHODS: A multicenter, prospective, observational, single-arm, post-marketing surveillance study was conducted in patients aged ≥ 18 years with moderate-to-severe plaque psoriasis and prescribed with ixekizumab in 26 Chinese hospitals. Psoriasis Area and Severity Index (PASI) and Dermatology Life Quality Index (DLQI) scores were compared between patients with versus without psoriasis in special body areas in the overall study population and across subgroups by body area. RESULTS: In total, 612 patients were included. At baseline, most patients (93.6%) had psoriasis involvement in at least one special body area. Overall, patients with psoriasis in special body areas reported a worse quality of life (QoL) than those without. Patients with versus without psoriasis in special body areas achieved a comparable mean reduction from baseline in PASI score (10.9 vs. 9.2 at week 2, and 16.9 vs. 14.7 at week 12, respectively) and DLQI score (6.0 vs. 4.4 at week 2, and 9.9 vs. 7.5 at week 12, respectively); a similar proportion of patients also achieved PASI 50 at week 2, and PASI 75 and PASI 90 at week 12, and a DLQI (0/1) at weeks 2 and 12. Several significantly different results were reported between subgroups, the majority of which favored patients with special body area involvement. CONCLUSION: Most patients had psoriasis involvement in a special body area which was associated with worse QoL. Ixekizumab is similarly effective in reducing disease severity and improving QoL in patients with plaque psoriasis across different special body areas.

Using ultrasonic-assisted sodium bicarbonate treatment to improve the gel and rheological properties of reduced-salt pork myofibrillar protein.

To study the impact of ultrasonic duration (0, 30, and 60 min) and sodium bicarbonate concentration (0% and 0.2%) on the gel properties of reduced-salt pork myofibrillar protein, the changes in cooking yield, colour, water retention, texture properties, and dynamic rheology were investigated. The findings revealed that added sodium bicarbonate significantly increased (P < 0.05) cooking yield, hardness, springiness, and strength of myofibrillar protein while reducing centrifugal loss. Furthermore, the incorporation of sodium bicarbonate led to a significant decrease in L⁎, a⁎, b⁎, and white values of cooked myofibrillar protein; these effects were further amplified with increasing ultrasonic duration (P < 0.05). Additionally, storage modulus (G') significantly increased for myofibrillar protein treated with ultrasonic-assisted sodium bicarbonate treatment resulting in a more compact gel structure post-cooking. In summary, the results demonstrated that ultrasonic-assisted sodium bicarbonate treatment could enhance the tightness of reduced-salt myofibrillar protein gel structure while improving the water retention and texture properties.

Effects of low-frequency magnetic field on solubility, structural and functional properties of soy 11S globulin.

BACKGROUND: Soy 11S globulin has high thermal stability, limiting its application in the production of low-temperature gel foods. In this study, the low-frequency magnetic field (LF-MF, 5 mT) treatment (time, 30, 60, 90, and 120 min) was used to improve the solubility, conformation, physicochemical properties, surface characteristics, and gel properties of soy 11S globulin. RESULTS: Compared with the native soy 11S globulin, the sulfhydryl content, emulsifying capacity, gel strength, water-holding capacity, and absolute zeta potential values significantly increased (P < 0.05) after LF-MF treatment. The LF-MF treatment induced the unfolding of the protein structure and the fracture of disulfide bonds. The variations in solubility, foaming properties, viscosity, surface hydrophobicity, and rheological properties were closely related to the conformational changes of soy 11S globulin, with the optimum LF-MF modification time being 90 min. CONCLUSION: LF-MF treatment is an effective method to improve various functional properties of native soy 11S globulin, and this study provides a reference for the development of plant-based proteins in the food industry. © 2024 Society of Chemical Industry.

Diagnostic significance of HRCT imaging features in adult mycoplasma pneumonia: a retrospective study.

Mycoplasma pneumoniae pneumonia (MPP) often overlaps with the clinical manifestations and chest imaging manifestations of other types of community-acquired pneumonia (CAP). We retrospectively analyzed the clinical and imaging data of a group of patients with CAP, summarized their clinical and imaging characteristics, and discussed the diagnostic significance of their certain HRCT findings. The HRCT findings of CAP researched in our study included tree-in-bud sign (TIB), ground-glass opacity (GGO), tree fog sign (TIB + GGO), bronchial wall thickening, air-bronchogram, pleural effusion and cavity. The HRCT findings of all cases were analyzed. Among the 200 cases of MPP, 174 cases showed the TIB, 193 showed the GGO, 175 showed the tree fog sign, 181 lacked air-bronchogram. In case taking the tree fog sign and lack of air-bronchogram simultaneously as an index to distinguish MPP from OCAP, the sensitivity was 87.5%, the specificity was 97.5%, the accuracy was 92.5%. This study showed that that specific HRCT findings could be used to distinguish MPP from OCAP. The combined HRCT findings including the tree fog sign and lacked air-bronchogram simultaneously would contribute to a more accurate diagnosis of MPP.

Dried lemon slices improve bowel cleansing quality of polyethylene glycol for colonoscopy preparation: randomized controlled trial

Background: adequate bowel preparation is related to the quality of colonoscopy. Dried lemon slices can increase gastrointestinal peristalsis, which has shown potential as an adjuvant of bowel preparation. We hypothesized that the combination of dried lemon slices and polyethylene glycol (PEG) could improve the efficacy of bowel preparation and be more acceptable to participants. Aim: to investigate the effectiveness of lemon slices combined with PEG for colonoscopy preparation. Methods: a prospective, single-center, randomized, controlled trial was performed of 521 patients randomly assigned to two groups. A total of 254 patients were given lemon slices based on conventional 4-L PEG treatment for the bowel, while 267 patients received only 4-L PEG treatment. Patients’ basic information, procedure-related parameters, adverse effects, and subjective feelings were collected by questionnaires. Intestinal tract cleanliness was scored according to the Boston Bowel Preparation Scale (BBPS) by experienced endoscopists. Data were analyzed by the two-sample t-test or the Chi-squared test. Results: the BBPS scores were significantly higher in the PEG + lemon slice group (p < 0.05). The taste acceptability, satisfaction, and willingness to repeat bowel preparation were significantly higher in the PEG+ lemon slice group (p < 0.05). However, a larger proportion of patients from the PEG+ lemon slice group (30.7 %) suffered abdominal distension compared with the PEG group (20.6 %), while the incidence of other adverse effects was comparable between the two groups. Conclusion: the addition of dried lemon slices to conventional PEG showed its superiority for bowel preparation (AU)

Dried lemon slices improve bowel cleansing quality of polyethylene glycol for colonoscopy preparation: randomized controlled trial.

BACKGROUND: adequate bowel preparation is related to the quality of colonoscopy. Dried lemon slices can increase gastrointestinal peristalsis, which has shown potential as an adjuvant of bowel preparation. We hypothesized that the combination of dried lemon slices and polyethylene glycol (PEG) could improve the efficacy of bowel preparation and be more acceptable to participants. AIM: to investigate the effectiveness of lemon slices combined with PEG for colonoscopy preparation. METHODS: a prospective, single-center, randomized, controlled trial was performed of 521 patients randomly assigned to two groups. A total of 254 patients were given lemon slices based on conventional 4-L PEG treatment for the bowel, while 267 patients received only 4-L PEG treatment. Patients' basic information, procedure-related parameters, adverse effects, and subjective feelings were collected by questionnaires. Intestinal tract cleanliness was scored according to the Boston Bowel Preparation Scale (BBPS) by experienced endoscopists. Data were analyzed by the two-sample t-test or the Chi-squared test. RESULTS: the BBPS scores were significantly higher in the PEG + lemon slice group (p < 0.05). The taste acceptability, satisfaction, and willingness to repeat bowel preparation were significantly higher in the PEG+ lemon slice group (p < 0.05). However, a larger proportion of patients from the PEG+ lemon slice group (30.7 %) suffered abdominal distension compared with the PEG group (20.6 %), while the incidence of other adverse effects was comparable between the two groups. CONCLUSION: the addition of dried lemon slices to conventional PEG showed its superiority for bowel preparation.

Ten-Day Vonoprazan-Amoxicillin Dual Therapy vs Standard 14-Day Bismuth-Based Quadruple Therapy for First-Line Helicobacter pylori Eradication: A Multicenter Randomized Clinical Trial.

INTRODUCTION: Whether 10-day short-course vonoprazan-amoxicillin dual therapy (VA-dual) is noninferior to the standard 14-day bismuth-based quadruple therapy (B-quadruple) against Helicobacter pylori eradication has not been determined. This trial aimed to compare the eradication rate, adverse events, and compliance of 10-day VA-dual regimen with standard 14-day B-quadruple regimen as first-line H. pylori treatment. METHODS: This prospective randomized clinical trial was performed at 3 institutions in eastern China. A total of 314 treatment-naive, H. pylori -infected patients were randomly assigned in a 1:1 ratio to either 10-day VA-dual group or 14-day B-quadruple group. Eradication success was determined by 13 C-urea breath test at least 4 weeks after treatment. Eradication rates, adverse events, and compliance were compared between groups. RESULTS: Eradication rates of VA-dual and B-quadruple groups were 86.0% and 89.2% ( P = 0.389), respectively, by intention-to-treat (ITT) analysis; 88.2% and 91.5% ( P = 0.338), respectively, by modified ITT analysis; and 90.8% and 91.3% ( P = 0.884), respectively, by per-protocol (PP) analysis. The efficacy of the VA-dual remained noninferior to B-quadruple therapy in all ITT, modified ITT, and PP analyses. The incidence of adverse events in the VA-dual group was significantly lower compared with that in the B-quadruple group ( P < 0.001). Poor compliance contributed to eradication failure in the VA-dual group ( P < 0.001), while not in the B-quadruple group ( P = 0.110). DISCUSSION: The 10-day VA-dual therapy provided satisfactory eradication rates of >90% (PP analysis) and lower rates of adverse events compared with standard 14-day B-quadruple therapy as first-line H. pylori therapy. TRAIL REGISTRATION NUMBER: ChiCTR2300070100.

Cluster analysis of multiple impairment measures in evidence-based classification for para-alpine sit skiers.

The International Paralympic Committee has been promoting the development of evidence-based classification to reduce the subjectivity in current decision-making systems. The current study aimed to evaluate the validity of the impairment and performance tests for para-alpine sit skiing classification, and whether cluster analysis of the measures would produce a valid classification structure. Thirty-eight para-alpine sit skiers with different disabilities completed seven tests. During these tests, isometric trunk strength, trunk muscle excitation, trunk range of movement (ROM), and simulated skiing performance (board tilt angle) were assessed. Correlations between the measures and the board tilt angle were calculated. To group athletes, K-means cluster analysis was performed according to how much the impairment measures affected the board tilting. There were significant correlations between all measures and the maximal board tilt angle (r = 0.35-0.81, p < 0.05). The cluster analysis revealed that the introduction of ROM and muscle excitation was an effective supplement to strength measures in improving the classification accuracy (53%-79%). It produced four clusters with strong structures (mean silhouette coefficient = 0.81) and large and significant inter-cluster differences in most measures and performance between clusters (p < 0.05). The cluster analysis produced classes comprising athletes with similar degrees of activity limitation. All tests reported can help establish a more transparent classification system for para-alpine sit skiers. This study also provides a reference for evidence-based classification systems in other Para sports.