Experimental tests of habitat preferences in the Comal Springs dryopid beetle, Stygoparnus comalensis
The Comal Springs dryopid beetle, Stygoparnus comalensis Barr and Spangler (Coleoptera: Dryopidae), is a federally endangered species endemic to three spring systems in central Texas, United States. Improving our understanding of the biology of this species is necessary for making progress towards the goals of its protection: establishing a monitoring program and maintaining captive reproducing populations. A series of experiments were conducted in captivity to empirically examine habitat preferences of S. comalensis while using a similar co-occurring species, Stenelmis sexlineata Sanderson, for comparison. Stygoparnus comalensis had a strong affinity for wood over leaves and rocks and had fuller guts when offered wild-conditioned wood compared with captive-conditioned wood. Adults and larvae of S. sexlineata were also attracted to wood when offered rocks, but did not prefer wood when also offered leaves. Both species responded to light, but responses were light- and species-specific, with S. comalensis avoiding shorter wavelength light and being attracted to longer wavelength light whereas S. sexlineata seemed to hide from all light types. Both species were attracted to conspecifics but not heterospecifics. Stygoparnus comalensis did not exhibit any clear response to flowing water (S. sexlineata was not examined). These results provide insight into the potential adaptations of a spring-endemic beetle species and environmental relationships that can potentially be used for improving monitoring and conservation of wild populations.
Pintar (2025) Experimental tests of habitat preferences in the Comal Springs dryopid beetle, Stygoparnus comalensis. PeerJ 13:e20507 https://doi.org/10.7717/peerj.20507
Impact of bacterial culture medium on composition and characteristics of Burkholderia pseudomallei extracellular polymeric substances
Extracellular polymeric substances (EPS) are essential for maintaining the structural integrity and function of biofilms. In this study, the influence of nutrient composition on biofilm formation and EPS production by Burkholderia pseudomallei was assessed using a quantitative assay after cultivation in brain heart infusion (BHI), Luria-Bertani (LB), and modified Vogel and Bonner medium (MVBM) for 2, 4 and 6 days. Biofilm biomass, the percentage of EPS in the biofilm matrix, and the biochemical composition of EPS were analyzed. The functional groups of EPS were characterized using Fourier transform infrared (FTIR) spectroscopy, while the microstructural features of the EPS were examined using scanning electron microscopy. We found that B. pseudomallei cultured in MVBM exhibited the highest biofilm biomass, despite having the lowest proportion of EPS within the biofilm matrix. In contrast, cultures in LB medium produced the lowest biofilm biomass but contained the highest percentage of EPS. These observations indicate that growth under high carbon/nitrogen (C/N) ratio, as in MVBM, favors biofilm biomass accumulation, whereas low C/N ratio conditions, such as LB and BHI, are associated with a high relative EPS content. Despite these differences, the carbon content of the EPS remained consistent across all media. Notably, the EPS derived from cultures grown in BHI, a nitrogen-rich medium, contained the highest protein content, which corresponded with noticeable amide peaks in FTIR spectra. Collectively, these findings enhance our understanding of how environmental C/N ratios influence B. pseudomallei biofilm development and EPS composition, with implications for bacterial persistence and adaptability in the environment.
Srithabut et al. (2025) Impact of bacterial culture medium on composition and characteristics of Burkholderia pseudomallei extracellular polymeric substances. PeerJ 13:e20488 https://doi.org/10.7717/peerj.20488
The investigation of fermented food consumption on gastrointestinal symptoms: a cross-sectional study in university students
Background Fermented foods (FFs) are a valuable source of live microorganisms that can enhance human health, particularly gastrointestinal health, akin to probiotics. This study investigated the relationship between FFs consumption habits and gastrointestinal system findings in university students. Methods A cross-sectional anonymous survey included 546 university students, collecting data on sociodemographic characteristics, the Gastrointestinal Symptom Rating Scale (GSRS), and the Bristol Stool Form Scale (BSFS). FFs consumption habits were recorded using a food frequency questionnaire. Results Results showed that the average GSRS score was 33.66 ± 16.89. According to the BSFS, 15% of students experienced constipation, 72.7% had moderate stool consistency, and 12.3% had diarrhea. Notably, kefir, vinegar, and sourdough bread were never consumed by 56.8%, 44.3%, and 41.9% of students, respectively. Significant differences were found between the frequency of yogurt, kefir, vinegar, cheese, pickle consumption, and gastrointestinal symptoms (p < 0.05). Students with normal stool consistency had fewer dyspepsia, abdominal pain, reflux symptoms, and overall gastrointestinal symptoms than those with constipation (p < 0.05). Conclusion The study concludes that FFs such as yogurt, cheese, pickles, and kefir may offer health benefits, reducing symptoms of reflux, dyspepsia, abdominal pain, and general gastrointestinal issues in young adults.
Seven Avuk et al. (2025) The investigation of fermented food consumption on gastrointestinal symptoms: a cross-sectional study in university students. PeerJ 13:e20479 https://doi.org/10.7717/peerj.20479
Design and simulation-based evaluation of a novel tracheostomy high-flow therapy device interface: a preclinical study
Background High-flow tracheal oxygen (HFTO) does not generate significant positive end-expiratory pressure (PEEP), which may limit its clinical applicability. We designed a novel high-flow tracheal interface (nHFTI) and compared the PEEP and other respiratory parameters it generated with those of the traditional high-flow tracheal interface (tHFTI) across a range of flow rates. Methods We conducted a randomized crossover bench study. A size 8 cuffed tracheostomy tube was connected to the high-flow therapy (HFT) device using two different interfaces. A high-fidelity lung simulator was used to model normal lung mechanics. Gas flow rates were set from 10 to 80 L/min at a gradient of 10 L/min, and the sequence was randomized. At each flow setting, the following parameters were recorded: PEEP, peak inspiratory pressure (PIP), peak expiratory pressure (PEP), end-inspiratory transpulmonary pressure (Ptp-EI), end-expiratory transpulmonary pressure (Ptp-EE), end-inspiratory cardiac pressure (PEIC) and end-expiratory cardiac pressure (PEEC), functional residual capacity (FRC), tidal volume (Vt) and fraction of inspired oxygen (FiO2). Results As the HFT flow rate increased, PEEP increased significantly with both the tHFTI and nHFTI (P < 0.001). Compared with the tHFTI, the nHFTI generated significantly higher PEEP across most flow rates (e.g., 3.4 vs. 1.0 cmH2O at 40 L/min; 7.3 vs. 3.1 cmH2O at 60 L/min, nHFTI vs. tHFTI, mean values). The nHFTI also generated higher PIP, PEP, Ptp-EI, Ptp-EE, PEIC, and PEEC, and resulted in a greater increase in FRC (P < 0.010). Compared with the tHFTI, the nHFTI maintained a relatively constant FiO2 and slightly reduced Vt at the same flow rate level. Conclusions The nHFTI generated a modest level of PEEP, increased FRC and slightly reduced Vt at flow rates of 40–60 L/min. This physiological profile suggests potential for maintaining lung expansion and improving cardiac function in heart failure. Further in vivo studies are needed to evaluate the clinical impact of nHFTI-mediated PEEP augmentation and determine whether it can lead to improved clinical outcomes, particularly in patients requiring prolonged mechanical ventilation during the weaning process.
Hou et al. (2025) Design and simulation-based evaluation of a novel tracheostomy high-flow therapy device interface: a preclinical study. PeerJ 13:e20445 https://doi.org/10.7717/peerj.20445
Multiomics analysis reveals flavonoid accumulation and biosynthesis across different cultivation years and localities of Gongronemopsis tenacissima (Dai-Bai-Jie)
Background The dried root of Gongronemopsis tenacissima (Roxb.) S. Reuss, Liede & Meve, traditionally known as Dai-Bai-Jie, is a medicinal plant used by the Dai ethnic group, primarily for detoxification. Due to extensive use, wild resources have become increasingly scarce, prompting domestication efforts in China. However, the accumulation patterns of secondary metabolites—particularly flavonoids, the main detoxifying components—and their biosynthetic mechanisms remain unclear. Methods This study investigated differences in flavonoid accumulation and transcriptional regulation in Dai-Bai-Jie cultivated for one, two, and three years at high altitudes, and three years at low altitudes. Transcriptome and widely targeted metabolome analyses were conducted. A total of 1,495 metabolites were identified using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS), with 943 showing differential accumulation across the four groups. All flavonoids were classified into six clusters using k-means clustering. Flavonoid levels were generally higher in plants cultivated for two and three years, with total metabolite content also more abundant in these groups. Two-year cultivation was recommended as the optimal harvesting strategy. Results A regulatory relationship was observed between genes such as phenylalanine ammonia-lyase, CYP73A, 4-coumarate: coenzyme A ligase, and flavonol synthase, and the flavonoid components in Dai-Bai-Jie. No significant differences were found in Shannon, Chao1, or abundance coverage estimator (ACE) indices of rhizosphere microorganisms across different cultivation years and locations. Conclusions This study elucidates the mechanisms of flavonoid accumulation and supports the scientific rationale for optimal harvesting years of Dai-Bai-Jie. The findings provide a valuable foundation for guiding large-scale cultivation and reducing reliance on wild resources.
Wang et al. (2025) Multiomics analysis reveals flavonoid accumulation and biosynthesis across different cultivation years and localities of Gongronemopsis tenacissima (Dai-Bai-Jie). PeerJ 13:e20439 https://doi.org/10.7717/peerj.20439
Experimental assessment of the effects of sustainable landscaping practices on beetles in a new residential land development
As cities sprawl globally, the need for sustainable landscaping practices becomes more critical for addressing issues like water conservation, soil health, and local biodiversity. Beetles are valuable environmental indicators of insect habitat quality and are ecologically important. Here we experimentally assessed the response of ground-active beetle communities to sustainable landscaping practices (i.e., drought-tolerant native plants, reduced irrigation, and compost-amended soils) in an ongoing suburban development in Central Florida, one of the fastest growing regions in the USA. We assessed beetle activity density, diversity, and ecological functionality during the wet and dry seasons using pitfall traps, a well-tested technique for sampling ground arthropods. We hypothesized that the reduced compaction and better moisture retention of compost-amended soil would create better conditions for soil-dwelling beetles that use soil for egg deposition and larval development. We also hypothesized that plant growth-form traits would affect the spatial distribution of beetles within the experimental plots. Finally, we hypothesized that irrigation treatments would not affect beetle communities which are adapted to the region’s seasonal rainfall patterns. Results showed that beetle species richness positively correlated with percent cover of native ground cover forbs, and that beetle activity density tended to decline with increasing pine straw mulch coverage. Warmer soils enhanced both richness and activity density, while both of these metrics exhibited a hump-shaped pattern relative to soil moisture, peaking at intermediate levels. Trait-environment relationships revealed that beetle traits, including diet, body size, and larval substrate use, varied with microclimatic conditions. Trait diversity rose with species richness but plateaued due to trait saturation, while uneven trait distribution suggested filtering and niche separation driven by short-term climatic conditions. This work highlights the importance of research aimed at identifying landscaping approaches that both support insect biodiversity and meet environmental sustainability objectives in urbanizing landscapes.
Pandolfi et al. (2025) Experimental assessment of the effects of sustainable landscaping practices on beetles in a new residential land development. PeerJ 13:e20415 https://doi.org/10.7717/peerj.20415
Diabetes and respiratory diseases as comorbid conditions in COVID-19 patients from Kazakhstan: a retrospective pilot study
Background Diabetes and respiratory diseases are prevalent in Central Asia, and their prevention represents an opportunity to increase life expectancy in the region, especially in Kazakhstan. This study aims to analyze trends in the prevalence of diabetes and respiratory diseases as comorbidities in patients with recent COVID-19 infections, based on the information obtained from several clinics in Almaty, Kazakhstan. Methods This study was conducted as a cross-sectional analysis using de-identified electronic medical records from a multidisciplinary hospital in Almaty, Kazakhstan. Adults hospitalized with laboratory-confirmed COVID-19 during 2021–2022 were included (N = 292; mean age 55 years, range 18–91). Continuous variables were summarized with means and standard deviations, and categorical variables with counts and percentages. Data extraction and statistical analyses were performed in September–December 2023. Results The mortality rate was higher among patients with pneumonia (16.8%) compared to chronic bronchitis (10.6%). We identified a high level of comorbidity with diabetes (35.3% in the 45–59 age group) and chronic respiratory disease (37.9% in the same group). Discussion The mortality and comorbidity rates for hospitalized patients with recent COVID-19 infections in Almaty were high in comparison to other middle-income countries. These findings underscore the need for targeted early prevention strategies and public health interventions to address the rising burden of chronic diseases in Kazakhstan, particularly among middle-aged adults.
Tazhibayeva et al. (2025) Diabetes and respiratory diseases as comorbid conditions in COVID-19 patients from Kazakhstan: a retrospective pilot study. PeerJ 13:e20413 https://doi.org/10.7717/peerj.20413
Effects of different rehydration temperatures on rehydration and nutritional quality of dried daylily
Daylily is a unique cash crop in China which uses the unopened flower buds as food organs. Fresh daylily easily deteriorates and dried daylily is the main supply form in the market at present. The main goal of this work is to determine dried daylily water rehydration properties and sugar, lignin, cellulose, carotenoid, flavonoid and polyphenol retention properties under different temperatures and time periods. In this study, daylily was soaked at room temperature (25 °C), 50 °C and 70 °C for different durations. The results showed that after rehydration, the brightness index of daylily increased, while the redness and yellowness value decreased. The higher the water temperature, the faster the water absorption expansion rate and the higher the rehydration rate of the dried daylily, but the higher water temperature can cause the destruction of the microstructure of the daylily. The soluble sugars of dried daylily were easily lost in the rehydration process, the contents of lignin, cellulose and carotenoid were relatively stable. The contents of polyphenols and flavonoids decreased significantly with the increase of rehydration time. The rehydration of dried daylily can be carried out at room temperature, and it is recommended that the rehydration time take 0.5 h.
Liu et al. (2025) Effects of different rehydration temperatures on rehydration and nutritional quality of dried daylily. PeerJ 13:e20408 https://doi.org/10.7717/peerj.20408
Acclimation and degradation characteristic of the microbial system in corn straw
Background Lignocellulose represents a significant biological resource in corn straw, yet its efficient degradation presents challenges. Purpose This study aimed to enhance the degradation rate of lignocellulose to expand the utility of corn straw. Methods A microbial system capable of degrading corn straw was acclimatized at an initial temperature of 30 °C using a static temperature limiting cultivation method. Results During the biodegradation process via fermentation, the concentration of organic acids peaked on the third day before gradually declining. Concurrently, the concentration of soluble sugars reached a maximum of 8.9 µg mL−1 on the third day, while the total sugar content swiftly reduced from 4 mg mL−1 to 1.6 mg mL−1 within the initial three days and subsequently stabilized. The glycoside hydrolases (GHs) and glycosyl transferases (GTs) emerged as two pivotal enzyme groups, comprising 4,837 and 1,882 genes, respectively. Notably, the hemicellulase and cellulase family genes within the GHs played a crucial role in breaking down hemicellulose and cellulose. A variety of lignocellulose-degrading enzymes were identified among the GHs. Under optimal conditions, the microbial system demonstrated a high efficiency in degrading corn straw, achieving degradation rates of 56.83% for lignin, 39.45% for cellulose, and 32.86% for hemicelluloses. Conclusion The microbial system domesticated by the restrictive culture method has a good ability to degrade lignocellulose of corn straw, which can further promote the process of corn straw feed.
Yu et al. (2025) Acclimation and degradation characteristic of the microbial system in corn straw. PeerJ 13:e20386 https://doi.org/10.7717/peerj.20386
Accuracy of high-frequency musculoskeletal ultrasound in hand trauma: a retrospective surgical field-based validation study at a single center
Background This study aims to assess the diagnostic accuracy of high-frequency musculoskeletal ultrasound in hand trauma patients, with a specific focus on tendon injury, avulsion fracture, and nerve damage, compared to surgical observations. Methods A retrospective study was carried out on 47 hand trauma patients who received high-frequency ultrasound examinations followed by surgical intervention from January 2022 to December 2024. Ultrasound assessment with the echoes, continuity, and alterations of tendons, nerves, and bone cortex, and the surgical findings were compared with the ultrasound features. The diagnostic accuracy of ultrasound was evaluated according to surgical outcomes. Results High-frequency ultrasound exhibited excellent diagnostic accuracy for tendon ruptures, achieving 92.86% for flexor tendons and 100% for extensor tendons, as well as 100% for avulsion fractures. Nonetheless, the accuracy was lower for tendon tears and nerve injuries, with 33.33% and 40%, respectively. Adding passive motion during ultrasound examination can enhance the accuracy of diagnosing tendon injury. Conclusion High-frequency ultrasound provided a dependable imaging technique for the diagnosis of tendon rupture and avulsion fracture in hand trauma. It may enhance clinical assessment and guide treatment selection for hand trauma patients.
Wang et al. (2025) Accuracy of high-frequency musculoskeletal ultrasound in hand trauma: a retrospective surgical field-based validation study at a single center. PeerJ 13:e20514 https://doi.org/10.7717/peerj.20514