Search

Nearest-neighbour clustering is a simple yet powerful machine learning algorithm that finds natural application in the decoding of signals in classical optical-fibre communication systems. Quantum k-means clustering promises a speed-up over the classical k-means algorithm; however, it has been shown to not currently provide this speed-up for decoding optical-fibre signals due to the embedding of classical data, which introduces inaccuracies and slowdowns. Although still not achieving an exponential speed-up for NISQ implementations, this work proposes the generalised inverse stereographic projection as an improved embedding into the Bloch sphere for quantum distance estimation in k-nearest-neighbour clustering, which allows us to get closer to the classical performance. We also use the generalised inverse stereographic projection to develop an analogous classical clustering algorithm and benchmark its accuracy, runtime and convergence for decoding real-world experimental optical-fibre communication data. This proposed ‘quantum-inspired’ algorithm provides an improvement in both the accuracy and convergence rate with respect to the k-means algorithm. Hence, this work presents two main contributions. Firstly, we propose the general inverse stereographic projection into the Bloch sphere as a better embedding for quantum machine learning algorithms; here, we use the problem of clustering quadrature amplitude modulated optical-fibre signals as an example. Secondly, as a purely classical contribution inspired by the first contribution, we propose and benchmark the use of the general inverse stereographic projection and spherical centroid for clustering optical-fibre signals, showing that optimizing the radius yields a consistent improvement in accuracy and convergence rate.

Patellar tendinopathy (jumper's knee) has a high prevalence in jumping athletes. Excessive load on the patellar tendon through high volumes of training and competition is an important risk factor. Structural changes in the tendon are related to a higher risk of developing patellar tendinopathy. The critical tendon load that affects tendon structure is unknown. The aim of this study was to investigate patellar tendon structure on each day of a 5-day volleyball tournament in an adolescent population (16-18 years). The right patellar tendon of 41 players in the Australian Volleyball Schools Cup was scanned with ultrasound tissue characterization ( UTC) on every day of the tournament ( Monday to Friday). UTC can quantify structure of a tendon into four echo types based on the stability of the echo pattern. Generalized estimating equations ( GEE) were used to test for change of echo type I and II over the tournament days. Participants played between eight and nine matches during the tournament. GEE analysis showed no significant change of echo type percentages of echo type I ( Wald chi-square = 4.603, d.f. = 4, P = 0.331) and echo type II ( Wald chi-square = 6.070, d.f. = 4, P = 0.194) over time. This study shows that patellar tendon structure of 16-18-year-old volleyball players is not affected during 5 days of cumulative loading during a volleyball tournament. [ABSTRACT FROM AUTHOR]

Patellar tendinopathy (PT) is an injury with a high prevalence in sports. Knowledge of risk factors is essential for developing preventive measures and rehabilitation programmes. However, risk factors associated with PT have not yet been systematically studied. This review was undertaken to identify risk factors associated with PT. The literature was systematically searched to identify articles that investigated risk factors for PT. There was no strong or moderate evidence that any investigated risk factor was associated with PT. For nine risk factors there was some evidence: weight, body mass index, waist-to-hip ratio, leg-length difference, arch height of the foot, quadriceps flexibility, hamstring flexibility, quadriceps strength and vertical jump performance. Based on the present evidence, reducing body weight, increasing upper-leg flexibility and quadriceps strength and the use of orthotics may be beneficial treatment options. However, it should be stressed that the evidence for the nine identified risk factors was only limited. Therefore, there is a clear need for high-quality studies in order to identify the exact risk factors associated with PT. [ABSTRACT FROM AUTHOR]

Background Patellar tendinopathy has a multifactorial aetiology, and many potential risk factors have been described in the literature. Findings are conflicting though, and most research is conducted on elite athletes. Objective Aim of the study is to determine risk factors for patellar tendinopathy in a large representative sample of basketball and volleyball players. Design Cross-sectional survey using an online questionnaire. Setting Basketball and volleyball players of all playing levels. Participants All basketball and volleyball players between ages 18 and 35 years (n=7740) from the Dutch Basketball Association and the Dutch Volleyball Association were invited to complete the questionnaire. 1561 volleyball players completed the questionnaire. Assessment of risk factors The following independent variables were collected: Gender, age, body mass index, waist-to-hip ratio, years playing basketball/volleyball, hours of training during the last week, number of games during the last month, average hours of other sports per week, training increase compared to last year, playing surface, playing level and playing position. Main outcome measurements Presence of symptomatic patellar tendinopathy was the dependent variable. Results Risk factors for patellar tendinopathy were age, playing at the national level, being male and playing volleyball (compared to playing basketball). Risk factors for men and women were comparable. Among volleyball players outside hitters and middle blockers/hitters had an increased risk compared to setters. For basketball players no risk factors could be identified. No differences in risk factors were found between athletes with unilateral and bilateral patellar tendinopathy. Conclusion Several potential risk factors for patellar tendinopathy were identified. These findings should be taken into account for prevention and rehabilitation purposes. [ABSTRACT FROM PUBLISHER]

To develop a core outcome set for Achilles tendinopathy (COS-AT) for use in clinical trials we performed a five-step process including (1) a systematic review of available outcome measurement instruments, (2) an online survey on truth and feasibility of the available measurement instruments, (3) an assessment of the methodological quality of the selected outcome measurement instruments, (4) an online survey on the outcome measurement instruments as COS and (5) a consensus in-person meeting. Both surveys were completed by healthcare professionals and patients. The Outcome Measures in Rheumatology guidelines with a 70% threshold for consensus were followed. We identified 233 different outcome measurement instruments from 307 included studies; 177 were mapped within the International Scientific Tendinopathy Symposium Consensus core domains. 31 participants (12 patients) completed the first online survey (response rate 94%). 22/177 (12%) outcome measurement instruments were deemed truthful and feasible and their measurement properties were evaluated. 29 participants (12 patients) completed the second online survey (response rate 88%) and three outcome measurement instruments were endorsed: the Victorian Institute of Sports Assessment-Achilles questionnaire, the single-leg heel rise test and evaluating pain after activity using a Visual Analogue Scale (VAS, 0-10). 12 participants (1 patient) attended the final consensus meeting, and 1 additional outcome measurement instrument was endorsed: evaluating pain during activity/loading using a VAS (0-10). It is recommended that the identified COS-AT will be used in future clinical trials evaluating the effectiveness of an intervention. This will facilitate comparing outcomes of intervention strategies, data pooling and further progression of knowledge about AT. As COS-AT is implemented, further evidence on measurement properties of included measures and new outcome measurement instruments should lead to its review and refinement., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: The purpose of this study was to develop a multidisciplinary guideline for patellofemoral pain (PFP) and patellar tendinopathy (PT) to facilitate clinical decision-making in primary and secondary care., Methods: A multidisciplinary expert panel identified questions in clinical decision-making. Based on a systematic literature search, the strength of the scientific evidence was determined according to the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) method and the weight assigned to the considerations by the expert panel together determined the strength of the recommendations., Results: After confirming PFP or PT as a clinical diagnosis, patients should start with exercise therapy. Additional conservative treatments are indicated only when exercise therapy does not result in clinically relevant changes after six (PFP) or 12 (PT) weeks. Pain medications should be reserved for cases of severe pain. The additional value of imaging assessments for PT is limited. Open surgery is reserved for very specific cases of nonresponders to exercise therapy and those requiring additional conservative treatments. Although the certainty of evidence regarding exercise therapy for PFP and PT had to be downgraded ('very low GRADE' and 'low GRADE'), the expert panel advocates its use as the primary treatment strategy. The panel further formulated weaker recommendations regarding additional conservative treatments, pain medications, imaging assessments and open surgery ('very low GRADE' to 'low GRADE' assessment or absence of scientific evidence)., Conclusion: This guideline recommends starting with exercise therapy for PFP and PT. The recommendations facilitate clinical decision-making, and thereby optimizing treatment and preventing unnecessary burdens, risks and costs to patients and society., Level of Evidence: Level V, clinical practice guideline., (© 2024 The Author(s). Knee Surgery, Sports Traumatology, Arthroscopy published by John Wiley & Sons Ltd on behalf of European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

Cellular senescence is the state of permanent growth arrest. Chemotherapeutic drugs induce senescence, known as therapy-induced senescence. Although there are studies deciphering processes in senescence, more studies providing detailed information on therapy-induced senescence at the transcriptome level are needed. In order to understand temporal molecular changes of doxorubicin treatment in the course of senescence formation, two data sets from HeLa cells at 16 h and 72 h doxorubicin treatment were analyzed. GO BP enrichment, KEGG pathways and hub genes specific to or shared between 16 h and 72 h doxorubicin treated HeLa cells were identified. Genes functioning in p53 signaling were upregulated only in 16 h, while genes functioning in extracellular matrix organization were upregulated only in 72 h doxorubicin treated HeLa cells. Wound healing genes were gradually upregulated from 16 h to 72 h doxorubicin treatment and metabolic pathways were downregulated at both. ncRNA processing and ribosome biogenesis GO BP terms were enriched in upregulated genes at 16 h, while these terms were enriched in downregulated genes at 72 h senescent HeLa cells. According to our results, genes functioning in p53 signaling may be involved in the induction of senescence, but may not be required to maintain senescence in HeLa cells., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Propylene chlorohydrins (PCHs) are formed as byproducts in the reaction between starch and propylene oxide (PO). For hydroxypropylated (HP) starch applications in food, Joint FAO/WHO Expert Committee on Food additives (JECFA) set the maximum allowed total propylene chlorohydrin (PHC-t) residues level at 1 mg/kg., Objective: To develop an improved analytical method for the determination of the PCH-t content in starches in the low mg/kg range to replace the outdated JECFA method., Methods: A new GC-MS method that utilizes aqueous methanol as extraction medium for PCH. The GC-MS system is equipped with a programmable temperature vaporization injector and Stabilwax-DA column and uses helium as carrier gas. Quantitative detection is achieved in selected ion monitoring mode., Results: This single-laboratory validation (SLV) study showed good linear calibrations for both 1-chloro-2-propanol (PCH-1) and 2-chloro-1-propanol (PCH-2) in the concentration range of 0.5-4 mg/kg in dry starch. The lower LOQ of PCH-1 and PCH-2 was 0.2-0.3 mg/kg in dry starch, the reproducibility RSD (RSDR) at the concentration level of 1-2 mg/kg in dry starch was 3-5%, and the recovery values for both PCH-1 and PCH-2 were in the range of 78-112% at a concentration level of about 0.6 mg/kg in dry starch. Compared with the current, outdated JECFA method, the new GC-MS method is more sustainable, less laborious, and therefore more economical. The analytical capacity of the new method is 4-5 times higher than the analytical capacity of the old JECFA method., Conclusion: The GC-MS method is fit for a multi-laboratory trial (MLT)., Highlights: Based on the results of this SLV and the MLT (will be published in a second paper), the Joint FAO/WHO Expert Committee on Food Additives has recently decided to replace the outdated GC-FID JECFA method with the new GC-MS method for the determination of PCH-t content in starches., (© The Author(s) 2023. Published by Oxford University Press on behalf of AOAC INTERNATIONAL. All rights reserved. For permissions, please email: journals.permissions@oup.com.)