title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=228 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Silver nanoparticles can be sampled by ultrafiltration probe but elution into & recovery from plasma and Dulbecco’s Phosphate Buffered Saline differs in vitro link: https://peerj.com/articles/18388 last-modified: 2024-10-24 description: Locally sustained release antimicrobials such as silver nanoparticles (AgNPs) might prove useful in combating local infections. Their elution has been investigated in Phosphate Buffered Saline (PBS) including from poloxamer 407 (P407). No information exists on possible interactions with proteins, nor have ultrafiltration (UF) probes been evaluated to measure Ag. These investigations would provide helpful data prior to investigating the sustained release after subcutaneous implantation in vivo over time. We compared (1) the influence of elution fluid on AgNP elution, and (2) UF probe and direct sampling in vitro. Six AgNP-P407 specimens in a dialysis tube were placed in Dulbecco’s PPBS (DPBS) (n = 3) or canine plasma (n = 3) for 96 h on a stirred hot plate (37 °C and 600 rpm) and sampled 20 times. A 0.001 mg/mL AgNP solution was prepared in DPBS or plasma. Six pipette and UF probe samples were taken of each. Inductively coupled plasma mass spectrometry was used to analyze Ag. Stock plasma contained Ag. At 96 h, 5/6 dialysis tubes had not fully released AgNP. One peak in hourly Ag increase was present in DPBS (10–13 h), and two peaks in plasma (6–8 and 10–13 h). The hourly Ag increase in plasma decreased earlier than in DPBS. Ultrafiltration probe sampling was possible in both DPBS and plasma and resulted in higher Ag concentrations but with more variation. While in vitro use of DPBS might be more cost effective, plasma should be considered due to difference in elution and recovery. Ultrafiltration probes can be used to sample Ag, but results will have a greater degree of variation, and multiple samples and increased time points should be considered. creator: Marije Risselada creator: Robyn R. McCain creator: Miriam G. Bates creator: Makensie L. Anderson uri: https://doi.org/10.7717/peerj.18388 license: https://creativecommons.org/licenses/by-nc/4.0 rights: © 2024 Risselada et al. title: Effects of progessive vs. constant protocol whole-body vibration on muscle activation, pain, disability and functional performance in non-specific chronic low back pain patients: a randomized clinical trial link: https://peerj.com/articles/18390 last-modified: 2024-10-24 description: Background and ObjectiveNon-specific chronic low back pain (NSCLBP) is a prevalent condition causing significant disability and functional impairment. Whole-body vibration exercise (WBVE) has emerged as a new treatment method, but additional research is necessary to determine the optimal parameters of WBVE that would be beneficial for patients experiencing chronic low back pain (CLBP). This study aims to investigate the effects of two type of WBVE (constant vs progressive) on pain, disability, functional performance, and muscle activity in patients with NSCLBP.MethodsThirty-two individuals diagnosed with chronic low back pain (CLBP) without any specific causes were enrolled and randomly assigned to one of two intervention groups: a constant/fixed protocol WBVE group or a progressive protocol WBVE group. Participants underwent WBVE sessions for around 30 min, thrice weekly over a period of 8 weeks. Primary outcomes assessed included pain intensity, functional disability, functional performance, and electromyographic activity of core musculature, measured at baseline and upon completion of the intervention period. Temporal changes of each outcome variable across different periods and between groups were measured with repeated measures 2×2 mixed ANOVA. Further, the paired t-test was performed to compare pre- and post-treatment values within each group.ResultsSignificant improvements were observed in both the constant and progressive WBVE protocol groups. Pain intensity decreased by 64.2% (p < 0.001) in the constant group and by 61.1% (p < 0.001) in the progressive group. Functional disability decreased by 48.1% (p < 0.001) in the constant group and by 53.3% (p < 0.001) in the progressive group. Functional performance improved by 16.5% (p < 0.001) in the constant group and by 16.9% (p < 0.001) in the progressive group. Electromyography (EMG) demonstrated significant improvements across all measured variables except % maximum voluntary isometric contraction (%MVIC) of external obliques (EO) in both intervention groups with time (p < 0.001). There was no statistically significant difference in the magnitude of improvement between the constant and progressive WBVE protocols (p > 0.05), indicating both modalities’ effectiveness in ameliorating CLBP symptoms and associated functional impairments.ConclusionThe study demonstrates that both progressive and constant WBVE protocols are equally effective in reducing pain and disability in NSCLBP patients. These findings support the inclusion of progressive WBVE in clinical practice, offering a flexible treatment option that can be tailored to individual patient needs, ensuring both tolerability and effectiveness. This contributes valuable evidence towards optimizing WBVE protocols for managing NSCLBP. creator: Tasneem Zafar creator: Saima Zaki creator: Md Farhan Alam creator: Saurabh Sharma creator: Reem Abdullah Babkair creator: Shibili Nuhmani uri: https://doi.org/10.7717/peerj.18390 license: https://creativecommons.org/licenses/by/4.0/ rights: ©Zafar 2024 et al. title: Combining citizen science, phylogenetics, and bioacoustics to inform taxonomy and conservation of the Near Threatened Proceratophrys paviotii (Anura, Odontophrynidae) link: https://peerj.com/articles/17990 last-modified: 2024-10-23 description: Herein, basel on novel data gathered by citizens scientists and specialists, we contribute to the improvement of scientific knowledge and conservation of the Near Threatened Proceratophrys paviotii in order to: 1) test for the first time the phylogenetic position and a species delimitation of P. paviotii through a molecular approach; 2) describe a larger sample of its advertisement call to properly encompass the species intraspecific variation; 3) describe for the first time the P. paviotii release call; and 4) provide novel insights on the species conservation status. Our 16S tree confidently grouped P. paviotii with P. cururu, P. renalis, and P. laticeps. The average sequence divergence between P. paviotii and its congeners ranged from 2.2% (P. laticeps) to 9.1% (P. redacta). Advertisement calls consisted of a single note with duration of 0.26–0.58 s, 17–41 pulses emitted at rate of 54.19–77.49 pulses/s and peak frequency of 775.19–947.46 Hz. Release calls consisted of a single note with duration of 0.04–0.43 s, 2–13 pulses emitted at rate of 21.17–81.58 pulses/s and peak frequency of 689.1–1,722.6 Hz. Additionally, our study strongly supports the notion that Citizen Science approaches can yield invaluable information concerning species’ geographic distribution and conservation. creator: João Victor Andrade Lacerda creator: Diego J. Santana creator: Carla Guimarães creator: Alice Zanoni dos Santos creator: Alan P. Araujo creator: Natalia Pirani Ghilardi-Lopes creator: Sarah Mângia uri: https://doi.org/10.7717/peerj.17990 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2024 Lacerda et al. title: Surface-functionalized PAN fiber membranes for the sensitive detection of airborne specific markers link: https://peerj.com/articles/18077 last-modified: 2024-10-23 description: PAN fibers are characterized by having a large surface-to-volume ratio and small pores, which are beneficial for applications in filtration and specific molecular detection systems. Naturally, larger items are filtered, and a lower ratio between specific and nonspecific binding is expected since small pores do not allow larger elements to penetrate through membranes; thus, nonspecific binding is enhanced. We prepared and tested fiber membranes (diameter cca 700 nm) functionalized with a specific antibody to prove that even microscopic systems such as bacteria could be specifically identified. In addition, we established a methodology that enabled the effective binding of bacteria in not only an aqueous environment but also air. Our data clearly prove that even large systems such as bacteria could be specifically identified by fiber membranes surface-functionalized with a specific antibody. This research opens the door to the construction of biosensors for the fast, inexpensive, and sensitive identification of airborne bacterial contaminants and other airborne pollutants. creator: Leontyna Varvarovska creator: Bruno Sopko creator: Dana Gaskova creator: Tomas Bartl creator: Evzen Amler creator: Tatana Jarosikova uri: https://doi.org/10.7717/peerj.18077 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2024 Varvarovska et al. title: Spontaneous space closure after extraction of young first permanent molar. Retrospective cohort study link: https://peerj.com/articles/18276 last-modified: 2024-10-23 description: BackgroundEarly compromised first-permanent-molar (FPM) extraction can adversely affect occlusion. However, the current literature does not provide sufficient support for definitive early extraction outcome. This cohort study aimed to evaluate the pattern of post-FPM extraction spontaneous space closure and its pre-extraction indicators.MethodsPatients of 7–13 years, with compromised FPM at three-tertiary-centers between 2015 and 2019 were retrospectively screened. Pre-extraction indicators were evaluated (extraction location, direction of the second permanent molar (SPM) long-axis, and SPM Demirjian development stage). Spontaneous space closure pattern was evaluated clinically and radiographically using the American Board of Orthodontics (ABO) grading system.ResultsIn total, 112 FPMs (73-patients) were identified and five (4.5%) of the extraction sites showed favorable combined-ABO-scores. Distal direction of the SPM long-axis in the maxillary arch significantly decreased the relative risk (RR) of having a SPM rotation/alignment ABO score-1 (P = 0.002; RR = 0.64). For the mandibular arch, Demirjian stage D and E significantly decreased the RR of having ABO score-1 for spacing between the SPMs and second premolars (P = 0.029; RR:0.57, P = 0.004; RR:0.53, respectively) and vertical dimension (P = 0.02; RR = 0.53).ConclusionsThe direction of the SPM long-axis and its developmental stage are key indicators of the favorable outcome pattern of spontaneous space closure after FPM early extraction. creator: Heba Jafar Sabbagh creator: Ahmad Adnan Samara creator: Shoroog Hassan Agou creator: Jihan Turkistani creator: Manal Ibrahim Al Malik creator: Hadeel Abdulatief Alotaibi creator: Abrar Shimi Dhaifallah Alsolami creator: Nada Othman Bamashmous uri: https://doi.org/10.7717/peerj.18276 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2024 Sabbagh et al. title: Effect of donor GSTM3 rs7483 genetic variant on tacrolimus elimination in the early period after liver transplantation link: https://peerj.com/articles/18360 last-modified: 2024-10-23 description: PurposeGlutathione S-transferase mu (GSTM) belongs to the group of phase II drug-metabolizing enzymes, and the GSTM1 genetic variant has been reported to have a potential association with the metabolism of immunosuppressive drug after renal transplantation. The effect of donor and recipient GSTMs genetic variants on tacrolimus (Tac) metabolism was the focus of our investigation in this study.MethodsA total of 203 liver transplant patients were recruited for the study. In the training set (n = 110), twenty-one SNPs in five genes (GSTM1-5) were genotyped by the drug-metabolizing enzymes and transporter (DMET) microarray. CYP3A5 rs776746 and GSTM3 rs7483 were genotyped using a Mass ARRAY platform in the validating set (n = 93).ResultsTac C/D ratios of donor GSTM3 rs7483 AA carriers were significantly lower than those with the G allele at weeks 1, 2, 3 and 4 after liver transplantation (LT). Multivariate analysis was conducted on the training set and validating set, donor and recipient CYP3A5 rs776746, donor GSTM3 rs7483 and total bilirubin were identified as independent predictors of Tac C/D ratios in the early period after LT. Combining CYP3A5 rs776746 and donor GSTM3 rs7483 genotypes, Tac C/D ratios were observed to be increasingly lower with increasing numbers of alleles associated with fast metabolism. Moreover, the risk of a supratherapeutic C0 (Tac > 15 ug/L) was significantly higher for poor metabolizers than the other groups at week 1 after LT.ConclusionsThere was a significant association between the donor GSTM3 rs7483 genetic variant and Tac metabolism in the early period after LT. Genotype classification might have a better predictive ability of the initial Tac doses. creator: Tao Zhang creator: Xiaorong Chen creator: Yuan Liu creator: Lei Zhang uri: https://doi.org/10.7717/peerj.18360 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2024 Zhang et al. title: Association between plain ropivacaine dose and spinal hypotension for cesarean delivery: a retrospective study link: https://peerj.com/articles/18398 last-modified: 2024-10-23 description: BackgroundData on the association between the plain ropivacaine dose and maternal hypotension during cesarean delivery are limited. Thus, this study aimed to explore this association.MethodsThis retrospective study included patients undergoing cesarean sections under spinal or combined spinal-epidural anesthesia with plain ropivacaine at The First Hospital of Fuyang, Hangzhou, China, between 2018 and 2022. Data were obtained from the anesthesia information management system. Liner trend tests were used to distinguish the linear relationship between spinal hypotension and the plain ropivacaine dose, and receiver operating characteristic curves were used to calculate the dose threshold. Logistic regression was used to adjust for confounders. Sensitivity analyses were performed to evaluate the stability of the results. The secondary outcome was vasopressor use (metaraminol and ephedrine).ResultsIn total, 1,219 women were included. The incidence of hypotension linearly correlated with the plain ropivacaine dose (adjusted P-value for trend, P < 0.001). Thus, we used a dose threshold of 17.5 mg to compare the dose as a binary variable (≥17.5 mg vs. < 17.5 mg). Plain ropivacaine doses of ≥17.5 mg were associated with a higher incidence of spinal hypotension (adjusted odds ratio: 2.71; 95% confidence interval [1.85–3.95]; P < 0.001). The sensitivity analyses yielded similar results. The plain ropivacaine dose also correlated with metaraminol use but not ephedrine use.ConclusionsThe incidence of spinal-induced hypotension in women undergoing cesarean section linearly correlated with the plain ropivacaine dose. The dose threshold for hypotension risk was 17.5 mg. creator: Min Li creator: Guohao Xie creator: Lihua Chu creator: Xiangming Fang uri: https://doi.org/10.7717/peerj.18398 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2024 Li et al. title: The effects of livestock grazing on physicochemical properties and bacterial communities of perlite-rich soil link: https://peerj.com/articles/18433 last-modified: 2024-10-23 description: Livestock grazing has been proposed as a cost-effective way to reclaim post-mining lands. It can enhance soil fertility and biodiversity, but its impacts on soil quality and microbial communities vary across soil types. Moreover, waste from grazing raises concerns about pathogens that could pose risks to animal and human health. This study investigated the effects of grazing on post-mining perlite-rich soil in central Thailand. A comparative analysis of soil physicochemical properties and bacterial diversity was conducted between grazed and ungrazed sites. Bacterial diversity was assessed using 16S amplicon sequencing. The perlite-rich soil was found to be sandy, acidic, and to have low nutritional content. Grazing significantly improved the soil texture and nutrient content, suggesting its potential as a cost-effective reclamation strategy. The 16S metagenomic sequencing analysis revealed that microbial communities were impacted by livestock grazing. Specifically, shifts in the dominant bacterial phyla were identified, with increases in Firmicutes and Chloroflexi and a decrease in Actinobacteria. Concerns about increased levels of pathogenic Enterobacteriaceae due to grazing were not substantiated in perlite-rich soil. These bacteria were consistently found at low levels in all soil samples, regardless of livestock grazing. This study also identified a diverse population of Streptomycetaceae, including previously uncharacterized strains/species. This finding could be valuable given that this bacterial family is known for producing antibiotics and other secondary metabolites. However, grazing adversely impacted the abundance and diversity of Streptomycetaceae in this specific soil type. In line with previous research, this study demonstrated that the response of soil microbial communities to grazing varies significantly depending on the soil type, with unique responses appearing to be associated with perlite-rich soil. This emphasizes the importance of soil-specific research in understanding how grazing affects microbial communities. Future research should focus on optimizing grazing practices for perlite-rich soil and characterizing the Streptomycetaceae community for potential antibiotic and secondary metabolite discovery. The obtained findings should ultimately contribute to sustainable post-mining reclamation through livestock grazing and the preservation of valuable microbial resources. creator: Jiraphan Premsuriya creator: Nontaphat Leerach creator: Phatcharin Laosena creator: Woranich Hinthong uri: https://doi.org/10.7717/peerj.18433 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2024 Premsuriya et al. title: A classification system for identifying persons with an unknown cardiovascular disease (CVD) status for a multiracial/ ethnic Caribbean population link: https://peerj.com/articles/17948 last-modified: 2024-10-22 description: BackgroundThe need for classification systems for cardiovascular disease (CVD) that is population-specific is important towards understanding the clinical disease and diagnostics associated with the disease. This paper presents the form and validation results of this classification system.MethodThe survey data used was captured from 778 participants, 526 persons with no prior CVD, and 252 who reported prior CVD. Binomial logistic regression and Discriminant analysis were utilised to develop classification models. This classification system provided a general measure of severity of disease by utilising scores estimated from two algorithms developed from 13 routine physiologic measurements, along with demographic information of age and ethnicity, inter alia, and previous health status.ResultsFor each model, specific score ranges were identified, which gave the best classification for those with a prior CVD incident (higher scores) and for others labelled as non-CVD (lower scores). The two classification models (Logistic Regression Model and Discriminant Analysis Model) developed had high area under the receiver-operating characteristic (AUROC) values (98% & 99%) and sensitivity (86 and 90%), which improved discrimination between Non-CVD and CVD participants and, more importantly, correctly classified a greater proportion of CVD participants. New to this type of research was the estimation and detailed evaluation of a range of scores, labelled non-differentiating, which fell in the middle of the spectrum and which contained the higher-end scores for the non-CVD individuals and the lower-end scores for CVD patients, all of whom were incorrectly classified, based on their prior history.ConclusionThe classification system of scores is able to differentiate the CVD status of individuals, with good predictability, and could assist physicians with recommending different treatment plans. The two models in this classification system each individually outperformed the three established models in terms of the strength of their correct classifications of individuals with or without prior reported CVD incidents. More importantly, they have smaller non-differentiating ranges than the three known models and, in that range, the two new models have lower CVD/non-CVD ratios suggesting they are more likely to misclassify non-CVD individuals compared to CVD patients, which is a more benign misclassification. Further, when used in combination, the two models increased the sensitivity, in classifying individuals of different ethnicities, beyond that of either one used independently or of any of the three standard European/North American models. These efforts will be instrumental in advancing personalised CVD management strategies and improving health outcomes across diverse populations. creator: Amalia Hosein creator: Valerie Stoute creator: Natasha Singh uri: https://doi.org/10.7717/peerj.17948 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2024 Hosein et al. title: Muscle synergies during the walk-run and run-walk transitions link: https://peerj.com/articles/18162 last-modified: 2024-10-22 description: BackgroundMuscular synergies could represent the patterns of muscular activation used by the central nervous system (CNS) to simplify the production of movement. Studies in walking-running transitions described up to nine synergy modules, and an earlier activation of flexor and extension ankle muscular groups compared to running or walking. Our project aims to study the behaviour of muscle synergies in different stance and swing variations of walking-running (WRT) and running-walking (RWT) transitions.MethodsTwenty-four trained men participated in this study. A variable speed protocol on a treadmill was developed to record the activity of 14 muscle during walking, running and relative transitions. The protocol was based on five ramps of 50 seconds each around ± 10 and 20% of the WRT speed. WRT and RWT were identified according to an abrupt change of the duty factor. Analysing surface electromyography using non-negative matrix factorization (NMF) we obtained synergy modules and temporal activation profiles. Alpha threshold for statistical tests set at 0.05.ResultsWe described four different transition strides, two for increasing speed transitions, and two for decreasing speed transitions. Four to six synergy modules were found in each condition. According to the maximum cosine similarity results, the two identified WRT conditions shared five modules, while the two RWT conditions shared four modules. WRT and RWT overall shared 4.33 ± 0.58 modules. The activation profiles and centres of activation revealed differences among conditions.DiscussionTransition occurred at step level, and transition strides were composed by walk-like and run-like steps. Compared with previous studies in running and walking, both transitions needed earlier activation of a comparable number of synergy modules. Synergies were affected by acceleration: during RWT the need to dissipate energy, to decrease the speed, was achieved by increasing the number of co-activating muscles. This was reflected in fewer synergy modules and different activation profiles compared to WRT. We believe that our results could be enforced in different applied fields, like clinical gait analysis, physiotherapy and rehabilitation, where plans including co-activation of specific muscular groups could be useful. Gait transitions are common in different sports, and therefore also application in training and sport science would be possible. creator: Leonardo Lagos-Hausheer creator: Samuel Vergara creator: Victor Munoz-Martel creator: Germán Pequera creator: Renata L. Bona creator: Carlo M. Biancardi uri: https://doi.org/10.7717/peerj.18162 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2024 Lagos-Hausheer et al.