title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=33 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Sniffin’ sticks smell identification test: exploring measurement properties in an adult Brazilian healthcare professionals sample link: https://peerj.com/articles/19733 last-modified: 2025-10-28 description: IntroductionOlfactory evaluation has gained significant attention in both neurological and otorhinolaryngological assessments, particularly following the COVID-19 pandemic where SARS-CoV-2 infection emerged as a frequent cause of chemosensory dysfunction. The Sniffin’ Sticks identification test is a widely used screening tool for olfactory function. This study aimed to investigate the psychometric properties, specifically validity evidence based on internal structure (unidimensionality) and relations to other variables (demographic effects), of the 16-item Sniffin’ Sticks odor identification test (SS-16) in a homogeneous sample of highly educated young and middle-aged Brazilian adults, while exploring item-specific demographic effects.MethodsA prospective observational cross-sectional study was conducted on 144 highly educated adults. The SS-16 was administered using the ‘Odor-on-lines’ paradigm. Rasch analysis assessed person-item mapping and fit statistics, while multiple regression analyses determined the effects of age, sex, and education on both overall and item-specific performance.ResultsRasch analysis supported the unidimensionality of the SS-16. Item difficulty varied, with peppermint, cinnamon, and fish being easiest to identify, while apple, turpentine, and liquorice were the most challenging. Item-level analyses revealed specific demographic influences: older age was associated with poorer identification of coffee (β = −0.05, p = 0.021) and cloves (β = −0.123, p = 0.001); female sex was associated with significantly better identification of rose (β = 1.15, p = 0.026); and higher education level positively impacted identification of cloves and anise (β = 0.122, p = 0.011). These item-specific effects suggest potential differential age-related vulnerability for certain odorants, possible hormonal influences on floral odor detection, and educational effects potentially linked to semantic processing of complex aromas. Smell identification capacity was classified as “very low” (P84, 16 points).ConclusionThis study provides insights into the psychometric properties of the SS-16 in a specific sample of Brazilian adults, demonstrating both general and item-specific demographic effects on olfactory performance. The identification of item-specific influences enhances understanding of the complex interplay between biological and sociocultural factors in olfaction. While the predominance of female participants and the homogeneous high educational profile limit broader generalizability, this analysis contributes preliminary reference data for this demographic and supports the potential utility of this culturally adapted SS-16 version for clinical screening in similar Brazilian settings. Future research requires more diverse samples to establish representative Brazilian norms. creator: Pedro Renato de Paula Brandão creator: Danilo Assis Pereira creator: Diógenes Diego de Carvalho Bispo creator: Felipe von Glehn creator: Laura Silveira-Moriyama creator: Simoneide Souza Titze-de-Almeida creator: Marcio Nakanishi creator: Felipe Saldanha-Araujo creator: Enrique Roberto Arganaraz creator: Adriana Pinheiro Ribeiro creator: Agda Lima dos Santos creator: Ricardo Titze-de-Almeida uri: https://doi.org/10.7717/peerj.19733 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2025 Brandão et al. title: Retrospective study: the value of GDF-15 and conventional markers in combination for clinical diagnosis of lung cancer link: https://peerj.com/articles/20281 last-modified: 2025-10-27 description: Lung cancer is a leading cause of morbidity and mortality worldwide, and effective biomarkers for its screening and monitoring are still lacking. This study aims to assess the diagnostic value of Growth Differentiation Factor 15 (GDF15) in lung cancer and its subtypes, compared to conventional biomarkers, to evaluate its potential as a predictive biomarker for lung cancer screening and monitoring. GDF15 levels were measured and analyzed in different subtypes of lung cancer and non-tumor controls. The correlation between GDF15 and the expression of eight conventional biomarkers was assessed by analyzing serum GDF15 levels in the markersnormal groups and the markershigh groups. The superiority of GDF15 in screening and monitoring of lung cancer was confirmed using the receiver operating characteristic (ROC) curve analysis of GDF15, alongside conventional biomarkers. Serum GDF15 levels were significantly higher in all subtypes of lung cancer compared with non-tumor controls, showing significant correlations with the levels of conventional biomarkers. ROC curve analysis demonstrated that GDF15 has superior sensitivity and specificity over conventional biomarkers, highlighting its potential as a promising diagnostic biomarker for lung cancer. GDF15 shows strong potential as a diagnostic tool for lung cancer, outperforming conventional markers. It presents a promising new biomarker for lung cancer monitoring and diagnosis. creator: Jingru Ni creator: Xiaohe Hao creator: Yongkang Wu creator: Cuiping Mao creator: Limin Niu creator: Heng Liu creator: Qinghai Lin uri: https://doi.org/10.7717/peerj.20281 license: https://creativecommons.org/licenses/by-nc/4.0 rights: © 2025 Ni et al. title: Accelerated straw decomposition and mitigated methane emissions via autumn puddling incorporation enhances soil health and yield stability in cold-region rice systems of China link: https://peerj.com/articles/20264 last-modified: 2025-10-27 description: This study discusses two challenges to rice production in China’s cold growing regions: the slow decomposition of straw due to low temperatures in the winter, and the environmental threats—concentrated methane emissions and soil reduction stress—associated with incorporation in the spring. To address these issues, a field experiment was conducted over two years (2022–2023) in paddy fields in central Jilin Province. The outcomes of three treatments were compared: no straw return (CK), puddling with water to promote straw incorporation in the spring (T1), and puddling with water to promote straw incorporation in the autumn (T2). The results demonstrated that T2 significantly enhanced the straw decomposition rate compared to T1 by extending the decomposition period, resulting in a 2.9% increase in straw weight loss after incorporation and a reduction in total methane emissions by 32.3%. T2 produced a smaller decline in soil redox potential, thereby alleviating soil reduction stress. Compared to CK, T2 significantly increased the levels of nitrogen, phosphorus , and calcium in the soil. T2 also maintained greater root activity and higher stem numbers than T1. While the grain yield under T2 did not differ significantly from that of CK, the yield under T1 was significantly reduced by 12.7%. Thus, incorporating puddling in autumn accelerates straw decomposition, reduces summer methane peaks, alleviates soil stress, enhances nutrient supply, and stabilizes yields. This makes it a sustainable strategy for managing straw in cold-region rice systems. creator: Bing He creator: Yonglin Si creator: Chao Li creator: Limin Wang uri: https://doi.org/10.7717/peerj.20264 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 He et al. title: Lower limb joints’ contributions to ballet turnout during unipodal and bipodal jumps in fifth position in pre-professional dancers link: https://peerj.com/articles/20263 last-modified: 2025-10-27 description: Turnout, a large external rotation of the lower limb joints, is a key element of jumps and of other postures in classical ballet technique. Correct transverse-plane alignment of body segments in turnout is critical to reduce technical errors and injury risk. Although many studies have examined turnout in static positions, there is a need for a deeper understanding of this element dynamically, particularly during uni- and bipodal jumps with body displacements in fifth position. Such insights could help improve the technique and the training protocols. This study investigated the external rotations of the hip, knee, and ankle in turnout during three phases (preparation, flight, and landing) of two jumps with displacement performed in the fifth position: one unipodal, the Sissone Ouvert, and one bipodal, the Assemblé Dessus. Twenty-eight pre-professional ballet dancers were analyzed with 10.9 ± 3.2 years of ballet practice, 12.4 ± 2.7 hours of weekly training and a passive hip external rotation (static turnout) of 53.9 ± 10.1 deg. The dancers were instrumented with 16 skin-markers according to the Plug-in-Gait protocol and an eight-camera motion analysis system recorded lower limb kinematics in the transverse plane of the self-selected leg. Temporal profiles of joint angles were time normalized and the external rotation peak of hip, ankle, and knee were compared across phases and joints by repeated measures analysis of variance (ANOVAs) and Newman–Keuls post hoc (p < 0.05). The external rotation peak of the ankle, knee, and hip differed across phases (p < 0.001) for both jumps. In the Assemblé, hip and knee rotation peaks exhibited a similar behavior between the preparation and flight, while the ankle reached its highest peak at landing (p = 0.022). In the Sissone’s preparation, knee and ankle peaks showed significantly greater rotation compared to hip (p < 0.001), whereas in the flight, the hip exhibited the highest rotation compared to the other joints (p < 0.001). The external rotation peak occurred in different instants in each phase and with respect to normalized jump duration (p < 0.001). In conclusion, the knee joint has little contribution to external rotations in the turnout; conversely, the ankle and the hip joints appear to be pivotal in maintaining the turnout respectively in the Assemblé and in the Sissone, the latter mainly during the flight phase. creator: Luciana C. Manfrim creator: Maria Isabel V. Orselli creator: Bianca M. Portela creator: Matheus O. Moutinho creator: Paolo Caravaggi creator: Isabel C.N. Sacco uri: https://doi.org/10.7717/peerj.20263 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Manfrim et al. title: PKPy: a Python-based framework for automated population pharmacokinetic analysis link: https://peerj.com/articles/20258 last-modified: 2025-10-27 description: We present PKPy, an open-source Python framework designed to automate population pharmacokinetic analysis workflows. The framework emphasizes user accessibility by minimizing the need for manual parameter initialization while maintaining analytical rigor. PKPy implements both one-compartment and two-compartment pharmacokinetic models (with and without first-order absorption) with integrated capabilities for parameter estimation, covariate analysis, and comprehensive diagnostics. The framework’s performance was evaluated through simulation studies across varying sample sizes (20–100 subjects) and model complexities. Results demonstrated robust parameter estimation for clearance and volume of distribution, with bias consistently below 3% and recovery rates exceeding 98% in one-compartment models. The framework successfully identified true covariate relationships with 100% accuracy across all scenarios, while maintaining high model fit quality (R2 ≥ 0.97). For two-compartment models, the framework showed comparable performance with slightly higher parameter bias (5–10%) but maintained excellent fit quality (R2 ≥ 0.99). Advanced validation metrics including average fold error (AFE) and absolute average fold error (AAFE) were implemented, with AFE values ranging from 1.01–1.03 and AAFE < 1.05 across test scenarios, indicating excellent prediction accuracy. The key pharmacokinetic parameters estimated by the framework include clearance (CL), volume of distribution (V or V1/V2 for two-compartment models), inter-compartmental clearance (Q), and when applicable, the absorption rate constant (Ka). Application to the classic Theophylline dataset demonstrated PKPy’s practical utility, achieving comparable results whether or not initial parameter estimates were provided. The framework successfully estimated population parameters with good model fit (R2 = 0.933) and automatically identified physiologically plausible covariate relationships. Comprehensive comparisons with existing software packages (Saemix+PKNCA, and simulated comparisons with nlmixr2) revealed PKPy’s advantages in computational efficiency, with installation times of 16s versus 96s and analysis times of 13–15s versus 101–102s. While PKPy employs a two-stage approach rather than full nonlinear mixed-effects modeling, it achieved consistent parameter estimates with minimal bias for data-rich scenarios. PKPy leverages Python’s scientific computing ecosystem to provide an accessible, transparent platform for pharmacokinetic analysis. The framework’s automated approach, support for multiple compartment models, and comprehensive workflow integration demonstrate the potential for reducing barriers to entry in pharmacometric analysis while maintaining scientific rigor. creator: Hyunseung Kong creator: Inyoung Kim creator: Byoung-Tak Zhang uri: https://doi.org/10.7717/peerj.20258 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Kong et al. title: Antimicrobial and scavenging potential of green synthesized silver/manganese bimetallic nanoparticles using Euphorbia cactus extract link: https://peerj.com/articles/20244 last-modified: 2025-10-27 description: The fabrication of novel nanomedicines in the pursuit of alternative therapeutics has increasingly embraced eco-friendly strategies. This study reports the phytogenic synthesis of bimetallic silver-manganese nanoparticles (Ag/MnNPs) through bio-reduction using non-toxic extract from aerial part of Euphorbia cactus as a sustainable and environmentally benign reducing and stabilizing agent. Advanced spectroscopic and microscopic characterization techniques were applied to elucidate the physico-chemical features of green synthesized Euphorbia cactus-mediated Ag/MnNPs (EC-Ag/MnNPs). The formed EC-Ag/MnNPs were predominantly spherical and uniform, with an average size of 18.32 nm. Fourier transform infrared spectroscopy (FTIR) analysis revealed the existence of multiple functional groups, indicating the involvement of Euphorbia cactus phytoconstituents in the synthesis, reduction and stabilization of EC-Ag/MnNPS. The energy-dispersive X-ray (EDX) estimation confirmed the elemental composition, showing 43.62% of silver and 18.71% manganese content. Both biogenic bimetallic EC-Ag/MnNPs and Euphorbia cactus (EC) extract exhibited excellent antimicrobial and scavenging potential. The bimetallic EC-Ag/MnNPs exerted superior antibacterial efficacy, with maximum inhibition zones of 38.15 ± 0.32 mm against Escherichia coli and 36.81 ± 0.51 mm against Salmonella Typhi. EC-Ag/MnNPs also showed remarkable antifungal efficacy against Candida glabrata (35.10 ± 0.39 mm) and Candida parapsilosis (33.82 ± 0.97 mm). Additionally, the biosynthesized EC-Ag/MnNPs showed strong, dose-dependent antioxidant activity, achieving a maximum scavenging efficiency of 96.12% at a concentration of 80 µg/mL. The results demonstrated significant antimicrobial and antioxidant properties of green-synthesized EC-Ag/MnNPs, underscoring their potential application in antimicrobial formulations and enhancement of medical device functionality. creator: Gadah A. Al-Hamoud creator: Musarat Amina creator: Nawal M. Al-Musayeib creator: Samiah Alhabardi creator: Mohsin Ul Haq creator: Saeed Akhtar uri: https://doi.org/10.7717/peerj.20244 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Al-Hamoud et al. title: The role of cerebral blood flow volume in cortical inhibition during postural changes link: https://peerj.com/articles/20233 last-modified: 2025-10-27 description: This study investigated how body posture impacts cerebral hemodynamics and brain bioelectrical activity, aiming to understand the mechanisms by which increased cerebral blood flow in a supine position might lead to cortical inhibition, potentially indicated by a reduction in alpha wave presence. The study also explored the neurovascular effects of dynamic tilting. Simultaneous electroencephalographic (EEG) and rheoencephalographic (REG) recordings were conducted on 40 healthy participants (mean age = 21.3 ± 1.4 years; 20 men and 20 women) during two postural tests. In Test 1, participants transitioned between sitting upright and lying supine. Test 2 followed a similar design, with the addition of dynamic tilting through passive oscillations between +10° and −10° on a tilt table. Results indicated that REG parameters –specifically rheographic wave amplitude (RWA), venous outflow (VO), and catacrotic time (CT) –increased notably in the supine position, particularly among male participants. In Test 1, men also exhibited a pronounced drop in alpha absolute spectral power (Pα) when moving from upright to supine, while Pα remained relatively stable in women. In Test 2, Pα showed minimal changes among men, whereas moderate reductions were observed in women, mainly in the supine position following dynamic tilting. Significant sex differences were noted in RWA, VO, and Pα, with these values generally higher in female participants. A strong negative correlation between RWA and Pα was observed in the male group during Test 1, with a similar but weaker trend in women. In Test 2, a negative correlation between RWA and Pα re-emerged in both groups, though it did not reach statistical significance. These findings suggest that baroreflex activity may be the primary driver of cortical inhibition, with changes in cerebral blood flow volume potentially playing a secondary role. Dynamic tilting had minimal impact on brain blood flow and mixed effects on Pα, though results may hint at a possible interference with baroreflex responses, which could attenuate cortical inhibition. Overall, this study demonstrates the use of combined REG and EEG during postural transitions as a tool for investigating the interaction between cerebral blood flow and brain activity. These findings and the methods used may have clinical relevance as a potential diagnostic approach for disorders involving impaired baroreflex function. creator: Arlan F. Sagirov creator: Timofey V. Sergeev creator: Maria V. Kuropatenko creator: Alexander V. Shabrov creator: Elizaveta A. Agapova creator: Alexey A. Anisimov creator: Alexander Z. Yafarov uri: https://doi.org/10.7717/peerj.20233 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Sagirov et al. title: Modulation of PI3K/AKT/mTOR and apoptosis pathway in colon cancer cells by the plant flavonoid fisetin link: https://peerj.com/articles/20225 last-modified: 2025-10-27 description: Colorectal cancer (CRC) is a complex multifactorial disease caused by genetic and epigenetic changes playing a vital role in its development and progression. Chemotherapy remains a major option in the treatment of CRC. However, due to its unintended effects on normal tissue, research on identifying plant-based therapeutic agents as an alternative treatment modality has gained attention. Fisetin, a plant-derived flavonoid, has shown promising effects as an anticancer agent against several human cancers, including colon cancer. However, there is limited research focusing on studying the mechanism of action of fisetin. The PI3K/AKT/mTOR pathway as a key regulator of cancer cells has become a promising target for potential anti-cancer development. This study examined the anti-cancer effects of fisetin, emphasizing its effects on the PI3K/AKT/mTOR and apoptosis pathways in human colon cancer Caco-2 cells. The Caco-2 cells were treated with different concentrations (15, 30, 60, 90, or 120 µM) of fisetin for 12 or 24 h. Cell viability was evaluated using the MTT assay, while the expressions of PI3K/AKT/mTOR pathway genes and apoptosis genes, BAX and BCL-2, were analyzed by qRT-PCR. Fisetin markedly decreased the cell viability in a dose- and time-dependent manner. Fisetin down-regulated BCL-2, PI3K, mTOR, and NF-κB gene expression while up-regulating BAX gene expression. This suggested the inhibition of PI3K/AKT/mTOR pathway and induction of apoptosis. GeneMANIA and OncoDB further corroborated these results. These data demonstrate that the antiproliferative effects of fisetin were medicated through the modulation of PI3K/AKT/mTOR and apoptosis pathway. Thus, the study underscores fisetin’s potential as a cancer-preventative drug against cancer. creator: Amal Alamoudi creator: Khlood Alqarni creator: Arwa Ishaq A. Khayyat creator: Tajamul Hussain creator: Salman Alamery uri: https://doi.org/10.7717/peerj.20225 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Alamoudi et al. title: Instability core training vs traditional core training on trunk strength and sprint performance among athletes: a systematic review and meta-analysis link: https://peerj.com/articles/20212 last-modified: 2025-10-27 description: BackgroundInstability core training (ICT) has been the focus of extensive research because of its proven benefits to athletes’ core muscle strength and sprint performance. However, there is a lack of systematic reviews explicitly evaluating the impact of instability core training (ICT) vs traditional core training (TCT) on athletes’ trunk strength and sprint performance. This study aims to conduct a systematic review and meta-analysis of the effects of ICT vs TCT on trunk strength and sprint performance among athletes.MethodThis study used guidelines for the systematic review and meta-analysis of PRISMA, Web of Science, EBSCOhost (SPORTDiscus), PubMed, Scopus, CNKI, and Google Scholar to collect original references in electronic databases. The Population, Intervention, Comparison, Outcome, and Study Design (PICOS) method was selected for the inclusion criteria. The physiotherapy evidence database (PEDro) scale was used to assess the scoring for articles’ risk of bias. The scoring of 12 studies ranges from 5–7 (out of 11 points), and study quality is moderate to high.ResultsOut of 285 identified studies, only 12 articles fulfilled all the eligibility criteria after screening. ICT could significantly improve trunk strength and sprint performance among various athlete populations using unstable surfaces or environments (i.e., BOSU ball, Swiss ball, wobble boards, suspension trainer, Sissel pillows, inflated disc, foam surface, Airex balance pad, Togu power ball, thera-band, elastic band and so on) than TCT using stable surfaces or environments (i.e., floor and bench). In addition, the ICT vs TCT intervention showed a moderate to large effect size (ES = −0.40–1.86; all p < 0.05) in improving trunk muscle strength and sprint performance.ConclusionThe finding suggests that different types of ICT benefit athletes, as this training method can effectively enhance trunk strength and sprint performance in athletes than TCT. Therefore, this study suggests that ICT should be considered in athletes’ daily training routines for trunk strength and sprint performance. creator: Jianxin Gao creator: Dan Liu creator: Jiahua Zhu creator: Qi Guo creator: Xiaopeng Wang uri: https://doi.org/10.7717/peerj.20212 license: https://creativecommons.org/licenses/by-nc/4.0 rights: © 2025 Gao et al. title: Agreement between BTS G-walk and GaitLab in spatiotemporal and pelvic angle measurements in active older adults link: https://peerj.com/articles/20189 last-modified: 2025-10-27 description: BackgroundAging impacts gait, a vital health indicator in older adults, reducing speed and increasing double support time, linked to falls and disability. The World Health Organization advises 150 min/week of moderate or 75 min/week of vigorous exercise, plus strength training, to sustain neuromuscular integrity and locomotor capacity associated with healthy gait patterns in older adults. While 3D motion capture is the gold standard for gait analysis, its cost and complexity limit use, boosting interest in portable inertial sensors like the BTS G-Walk. Yet, their accuracy in active older adults for spatiotemporal parameters and pelvic angles is underexplored, prompting this comparison with BTS GaitLab.MethodsFifty-nine active older adults (aged 65–87, mean 71.2 ± 5.5 years; eight men, 51 women) were assessed using BTS GaitLab (200 Hz cameras, 400 Hz force plates, Helen Hayes protocol, 18 markers) and BTS G-Walk (100 Hz, at L5) during four 10-meter walks at comfortable speed. Spatiotemporal parameters (cadence, speed, step length, stance/swing/support times) and pelvic angles (tilt, obliquity, rotation) were compared. Agreement used intraclass correlation coefficient (ICC), differences used paired t-tests, and variability used coefficient of variation (CV), with p < 0.05.ResultsSpatial parameters showed strong agreement: cadence (ICC = 0.98), speed (ICC = 0.96), step/stride length (ICC = 0.90–0.92), with no significant differences for cadence and speed (p > 0.05). Temporal parameters had weak agreement (e.g., stance time ICC = −0.18, swing time ICC = −0.54) and significant differences (p < 0.001). Pelvic angles had moderate agreement for tilt and obliquity (ICC = 0.48–0.78, p < 0.007), but low for rotation (ICC < 0.38, p > 0.038). Variability was high for double support time (CV 15.3–20.9%) and pelvic angles (CV > 27%). The sample (59) exceeds typical studies (7–23).ConclusionsBTS G-Walk accurately measures spatial gait parameters in active older adults, ideal for quick clinical assessments where 3D systems are unavailable. However, its weak temporal parameter and pelvic rotation performance, possibly due to 100 Hz sampling, L5 placement, and algorithms, limits detailed analysis like stability. With a large sample and pelvic angle focus, this study supports G-Walk as a complementary tool in gerontology, while noting needs for improved temporal and angular precision. creator: Rafael Bittencourt creator: Laura Kulczynski creator: César Marcon creator: Rafael Reimann Baptista uri: https://doi.org/10.7717/peerj.20189 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Bittencourt et al.