Search Results (309)

A low-voltage alternating current (AC) field (20 V peak-to-peak, 1 kHz) was superimposed on a conventional direct current (DC) electrospinning configuration in order to test whether the shape of that perturbation measurably alters fiber formation. A function generator delivered sinusoidal, pulsed (square), ramp and arbitrary (noise) waveforms to a foil-covered flat collector, while a standard DC high-voltage source (20 kV) drove the jet from the spinneret. Polyvinylpyrrolidone (PVP) nanofibers were characterized by scanning electron microscopy (SEM), fiber-diameter distribution analysis (FIJI/ImageJ), quantitative orientation analysis and contact profilometry. One-way analysis of variance across the six conditions was significant (F(5.594) = 5.56, p = 5.1 × 10⁻⁵) but the associated effect size was small (η² = 0.045). Relative to the connected control (237 ± 52 nm), the ramp (205.5 ± 43.9 nm), noise (201.3 ± 48.6 nm) and pulse (212.6 ± 70.0 nm) waveforms yielded significantly finer fibers (Tukey HSD, p = 0.0008, 0.0001 and 0.022, respectively); relative to the grounded control (215 ± 47 nm), no waveform reached significance. The ramp waveform produced the narrowest diameter distribution but, unexpectedly, the roughest mat of the four AC conditions (Ra = 1.95 µm against 0.74 µm for the grounded control), while the noise waveform gave both the smallest mean diameter and the smoothest mat (Ra = 0.61 µm); with a single profile per scan direction, these roughness values are descriptive rather than statistically compared. Quantitative orientation analysis using two independent estimators (structure tensor and fast Fourier transform) returned Herman orientation factors of S ≤ 0.13 for every condition, against S = 0.81 for a partially aligned reference population: no condition exceeded the isotropic noise floor of the FFT estimator (S95 = 0.141), and the three conditions that marginally exceeded the structure-tensor floor (S95 = 0.104) included the connected control, which received no oscillating signal. No waveform, including the pulsed waveform, produced fiber alignment attributable to the AC field. The applied AC amplitude corresponds to approximately 0.05% of the DC voltage, and the associated oscillating field (±50 V m⁻¹) is approximately three orders of magnitude smaller than the mean DC field (~1 × 10⁵ V m⁻¹); the electrohydrodynamic mechanisms discussed here are therefore presented as hypotheses requiring direct measurement rather than as established explanations. Within these limits, low-voltage waveform modulation is a simple, safe and retrofittable route to modest control of nanofiber diameter and mat uniformity in a single-polymer system, but it does not induce fiber alignment. Full article

The increasing cooling demand in residential sectors located in warm climates requires sustainable energy systems capable of supplying thermal loads with reduced environmental impact. This study presents an exergo-environmental assessment of a hybrid system based on a supercritical Brayton cycle coupled with an organic Rankine cycle (ORC). Solar radiation and biomass are used as energy sources to supply the cooling demand of a residential complex composed of 275 housing units constructed with Glass Mat fiberglass. The system was evaluated through exergy analysis to identify the main sources of irreversibility and life cycle assessment (LCA) to quantify environmental impacts during construction, operation, maintenance, and decommissioning stages. The exergetic results show that the solar field represents the largest source of irreversibility, accounting for 49.17% of the total, while the heater and evaporator are the components with the greatest improvement potential in the Brayton and ORC cycles, respectively. The exergo-environmental analysis indicates that the compressor in the Brayton cycle presents the highest environmental impact associated with exergy destruction (${\mathrm{B}}_{\mathrm{D}}$ = 76.16 mPts/h, ${\mathrm{B}}_{\mathrm{k}}$ = 77.65 mPts/h), while the ORC pump shows the highest impact in the ORC cycle (${\mathrm{B}}_{\mathrm{D}}$ = 60.57 mPts/h, ${\mathrm{B}}_{\mathrm{k}}$ = 60.58 mPts/h). Turbines exhibit the highest exergo-environmental fractions (16.70%, 16.41%, and 12.11%), which are mainly associated with their manufacturing stage. Full article

Yellow-flowered camellias are a sought-after rarity that has a narrow natural distribution in southern China and northern Vietnam. Belonging to the Camellia sect. Chrysantha Chang, many of the yellow-flowered camellia species are endangered. In this study, whole-genome resequencing (WGR) was applied to a collection of 25 yellow-flowered camellias in the United States of America to generate molecular markers and estimate genetic diversity. A total of 200,385,257 SNPs, 15,632,190 indels, 420,648 structural variations, and 9067 CNVs were identified among the 25 plants. There were 122 SNPs within the chalcone synthase (CHS) gene. Two groups of plants, C. nitidissima and hybrids, were distinctly separated from the other individuals. High within-population diversity and moderate among-population differentiation were found. Compared to the genetic diversity present in the native regions of yellow-flowered camellias, only a limited number of species have been introduced to the United States. The current study is the first report of whole-genome resequencing of yellow camellias and the first investigation of genetic diversity and structure of a collection of individuals from the U.S. This significant genomic resource shall have a meaningful impact on conservation and breeding, as well as on species identification and evolution studies. The genetic diversity information shall guide the efforts in breeding and the introduction of new species. Full article

Genetic variation in four wild Prunus taxa (P. fruticosa, P. erythrocarpa, P. verrucosa and P. griffithii var. tianshanica) was investigated for the first time using six chloroplast DNA regions (matK, r rpl16, ycf1_1, ycf1_2, ndhF and trnH–psbA) analysed through CAPS-based SNP detection. The results revealed weak chloroplast differentiation among P. erythrocarpa, P. verrucosa and P. griffithii var. tianshanica. However, chloroplast variation exhibited a strong geographic signal across the studied populations. The observed chloroplast variation primarily reflected geographic structuring rather than clear differentiation among these closely related taxa. In contrast, P. fruticosa showed distinct chloroplast haplotypes not shared with the other taxa. These findings demonstrate that the developed chloroplast CAPS marker system is effective for detecting chloroplast haplotype variation but has limited discriminatory power among closely related wild Prunus taxa. Further studies using nuclear markers and genome-wide approaches will be required to better resolve their genetic relationships and evolutionary history. Full article

Two new species of Carex (Cyperaceae), C. tianlinensis and C. leigongshanica, are described and illustrated based on morphological and molecular evidence. Phylogenetic analyses based on two nuclear (ETS and ITS) and three plastid (matK, trnL-F, and rpl32-trnL^(UAG)) DNA markers recovered C. tianlinensis and C. leigongshanica as two distinct, strongly supported monophyletic lineages within the Indica clade. The two new species form a well-supported sister pair that is in turn sister to C. perakensis. Morphologically, C. tianlinensis most closely resembles C. perakensis, but differs in having inflorescences arising near the apex of the culms, pistillate part of spikes sparsely 2–6-flowered, and style glabrous. C. leigongshanica is also morphologically similar to C. perakensis, but differs in having each inflorescence with 6–16 shorter spikes, spikes 0.7–1.5 cm long, sessile or subsessile, utricles shorter, 3–3.5 mm long, and leaf blades narrower, 3–5.5 mm wide. Detailed morphological descriptions, type designations, specimen citations, and information on habitat and phenology are provided for the two new species. Full article

Mimusops zeyheri Sond. is an underutilized indigenous fruit tree with significant nutritional, ecological, and socio-economic value in southern Africa. However, its domestication potential remains constrained by a limited understanding of intraspecific variation across geographically distinct populations. This study integrated morphological, sensory, and chloroplast genetic analyses to assess the diversity and population structuring of M. zeyheri in two regions of South Africa (Limpopo and Mpumalanga). A total of 40 trees (20 per region) were evaluated for fruit, nut, and leaf traits, while sensory attributes were assessed by 100 participants using a 9-point hedonic scale. Genetic diversity was examined using the chloroplast markers matK and trnH–psbA. Significant regional differences were observed in reproductive morphology, with Mpumalanga populations producing larger fruits (29.41 ± 0.61 mm) and nuts (2.11 ± 0.36 cm) than those from Limpopo. In contrast, sensory evaluation revealed consistently higher preference scores for Limpopo fruits across all attributes, particularly taste, aroma, and overall acceptability (mean scores 7.7–8.0 vs. 5.0–5.4). Genetic analyses identified two major chloroplast lineages corresponding broadly to geographic origin, alongside rare haplotypes indicating localized divergence. Leaf morphology remained largely conserved across regions. The combined evidence demonstrates strong regional structuring driven by both environmental gradients and historical genetic divergence. Importantly, the decoupling of fruit size and sensory preference highlights the need to prioritize quality traits in domestication strategies. These findings point to a promising domestication direction, through crossbreeding superior-tasting Limpopo genotypes with larger-fruited Mpumalanga genotypes to combine consumer-preferred sensory quality with an improved fruit size. These findings provide a foundation for conservation planning and the selection of superior genotypes for the development of M. zeyheri as a high-value indigenous fruit crop. Full article

Food products containing plant ingredients are particularly vulnerable to economically motivated adulteration (EMA), which poses risks to consumer trust and regulatory compliance. While traditional methods—such as microscopy, chemical profiling or targeted PCR—struggle to detect adulterants in processed food products or complex mixes, DNA metabarcoding offers a non-targeted, high-throughput alternative. This study presents a nanopore sequencing-based technique that is easy to implement, cost-effective and sufficiently sensitive to detect substitutions, with a focus on spices and herbal teas as model matrices. The method was evaluated using eight single-species reference samples and five commercial multi-ingredient products. It reliably detected undeclared contaminants (e.g., mint in oregano) and species substitutions. Compared to single-barcode approaches, the combination of ITS2 + matK + trnH-psbA markers achieved higher sensitivity. The proposed workflow requires minimal infrastructure and a 2–4-day turnaround time. However, factors such as DNA degradation in highly processed foods, database gaps, and biological diversity limited detection in some cases. These findings demonstrate the workflow’s potential as a first-line screening tool for food authenticity testing, aligning with requirements such as EU regulation 1169/2011 on food labelling or the FDA’s Economically Motivated Adulteration (EMA) program. Future work should validate the method against regulatory thresholds and expand testing to a broader variety of species and matrices. Full article

Cathetus yuanjiangensis Huan C. Wang, Feng Yang et Chao Chen (Phyllantheae, Phyllanthaceae), a new species from the dry-hot valleys of Southwest China, is described and illustrated herein. Morphologically, the new species can be easily distinguished from its congeners by the following combination of characters: leaves 1.5–4.5 cm long, 1–2 cm wide; staminate flowers sepals spreading 1.5–2.0 mm long; filaments connate into a 2–3 mm long column; styles 3, ca. 1.6 mm long, connate into a ca. 0.5 mm long column at base; stigmas spreading, slender, oblong, each bifid to 1/2, the lobes linear. Phylogenetic analyses based on two nuclear (ITS and PHYC) and three chloroplast (matK, accD-psaI and trnS-trnG) DNA makers recover C. yuanjiangensis as the sister clade to C. fasciculate among the sampled taxa. Detailed morphological descriptions, photographs, pollen morphology, and complete plastid genome characteristics of the new species are provided, along with a distribution map and a preliminary conservation assessment. Additionally, we propose a new combination, Cathetus beillei (Hutch.) Huan C. Wang et Feng Yang, based on the basionym Phyllanthus beillei Hutch., which was originally published in Flora of Tropical Africa. An updated identification key for all recognized species of C. subgen. Cathetus is provided. Full article

The reliable identification of cultivated and naturalised mulberries is complicated by morphological plasticity, the historical movement of the planting material, and partly discordant nuclear and plastid signals. We evaluated four field-identified Morus alba L. trees, one from each of four localities in Mangystau, Western Kazakhstan, using archived consensus sequences for ITS, matK, rbcL, and trnH-psbA, together with a low-coverage Oxford Nanopore Technologies (ONT) dataset. Because the design comprised one tree per locality (n = 4), analyses were restricted to accession-level descriptive comparisons, and no population-genetic, phylogeographic, or formal phylogenetic inference was attempted. Archived alignment summaries indicated mean pairwise distances of 0.13% for matK, 0.44% for ITS, 0.94% for rbcL, and 2.92% for trnH-psbA; these values are reported as retained dataset descriptors rather than estimates of population diversity. An additional product generated with Rosaceae-derived s6pdh primers was excluded because the target identity and orthology could not be verified. The ONT run yielded 19,958 pass reads (69.27 Mb; read N50 3574 bp). Reference-enriched assembly produced a 14,824 bp candidate plastid-associated contig, approximately 9.3% of a typical Morus plastome. Its short length, incomplete and non-collinear annotations, and the absence of retained depth, polishing, assembly graph, and join support diagnostics preclude its interpretation as a complete, circular, or structurally validated plastome. This study provides a transparent pilot baseline for Mangystau mulberries and establishes quality control criteria for replicated sampling, validated markers, and deeper organelle sequencing. Full article

The rare charophyte species Chara corfuensis, which has an almost exclusively Mediterranean distribution, was recorded for the first time in two small waterbodies in southern Serbia, deep inland and far from the coast. Habitat characteristics were described in detail, as was the morphometry of the collected specimens, which corresponded well with literature data. In particular, reproductive structures—oospores and gyrogonites—were analyzed in detail, as the previous data on oospores was scarce and none existed for gyrogonites. The genetic profile of the Serbian specimens was determined based on DNA barcoding of the matK and rbcL plastid genes, confirming their taxonomic identity and showing close evolutionary relationships with most species of the subsection Hartmania. Full article

Mountain ecosystems of Kazakhstan host geographically isolated Sibiraea populations, whose taxonomic status is complicated by overlapping morphology, environmental plasticity, and conflicting nomenclatural treatments. We compared 177 adult shrubs sampled at nine elevation-stratified sublocalities nested within three regional analytical groups (two S. altaiensis groups, n = 60 each; one S. tianschanica group, n = 57) using whole-shrub morphology, quantitative leaf anatomy, four soil variables, and a preliminary four-locus DNA-barcode comparison based on eight taxon-level consensus sequences (two taxa × four loci). One-way ANOVA identified regional-group differences in bush width (F(2,174) = 8.89, p < 0.001), vegetative offshoot number (F(2,174) = 21.85, p < 0.001), leaf-blade thickness (F(2,174) = 21.09, p < 0.001), soil pH (F(2,174) = 72.61, p < 0.001), electrical conductivity (F(2,174) = 41.22, p < 0.001), total nitrogen (F(2,174) = 40.21, p < 0.001), and total carbon (F(2,174) = 39.00, p < 0.001). In contrast, plant height and several vascular traits did not differ significantly, and most soil-trait associations were weak (|$\mathsf{\rho }$| ≤ 0.33). Across ITS, matK/KIM, psbA-trnH, and rbcL, the concatenated alignment showed 99.49% identity and an uncorrected p-distance of 0.51%; psbA-trnH (0.97%) and ITS (0.69%) were the most variable loci. The combined evidence demonstrates regional phenotypic and edaphic differentiation but does not establish independent evolutionary lineages because taxon and geography are confounded, and individual-level genetic variation was sparsely sampled. By establishing measurable baselines for demographic monitoring, habitat protection, provenance-based ex situ conservation, and future restoration, the study directly supports the sustainable management and long-term resilience of rare mountain-plant populations in Kazakhstan. Full article

Objective: The purpose of this exploratory study was to examine mean differences, reliability, and agreement between CP and W′ derived from a 3MAT performed after an ICT and values obtained during a standalone 3MAT performed on a separate day. Methods: Ten recreationally trained cyclists and triathletes completed four laboratory visits, including an ICT followed by a 3MAT after 30 min of recovery (same-day condition) and a standalone 3MAT performed on a separate day. CP and W′ were derived from both conditions and compared using paired t-tests and Bland–Altman agreement methods. Results: No systematic differences, but limited individual-level agreement were observed between same-day and separate-day conditions for CP (mean difference: 1.72 ± 36.5 W) or W′ (mean difference: 0.99 ± 5.9 kJ), with trivial to small effect sizes. Peak VO₂ values were also not significantly different across testing conditions (p = 0.483). However, Bland–Altman analysis revealed wide limits of agreement for both CP (−69.8 to 73.3 W) and W′ (−10.7 to 12.7 kJ), indicating substantial variability at the individual level. Conclusions: Although same-day testing does not introduce systematic bias in CP or W′ estimation, the wide limits of agreement suggest that these protocols are not interchangeable for individual monitoring. Same-day testing may be appropriate for group-level assessments but should be used with caution when applied to individual athlete monitoring. Full article

Nepeta govaniana and Nepeta subsessilis display metabolomes typical for the genus Nepeta L. (Lamiaceae), predominated by monoterpenoid iridoids and phenolic acids. Underexplored phytochemical composition and largely undefined biological potential are the main reasons for the underutilized status of these two intriguing species. This study fills some of the existing knowledge gaps by comprehensively analyzing the composition of methanol-soluble nonpolar, semi-polar, and polar metabolites in leaves, and providing the information about antimicrobial and antioxidant potential. Integration of comprehensive HPLC/MS and GC/MS metabolomics with plastid loci-derived (trnL-F, rbcL, and matK) phylogenetic data, revealed the phylogenetic relatedness of N. govaniana and N. subsessilis with congeneric species, and placed them within the Nepeta’s chemotype A whose members produce both iridoid aglycones and glycosylated iridoids. Methanol extracts of these two phylogenetically related species displayed a notable antioxidant potential, but were less efficient as antimicrobial agents. Such results draw from the predominance of methanol-soluble polar compounds (polyphenolics and iridoid glycosides), exhibiting respectable antioxidant potential, and lower abundance of nepetalactone-type iridoids, known as potent antimicrobials. N. govaniana is here highlighted as a slightly more efficient antimicrobial and antioxidant agent than N. subsessilis, which can be ascribed to a higher content of methanol-soluble metabolites in leaves. Full article

This study reports the physicochemical characterization and structure–property relationships of rigid sheep wool/phenolic novolac panels developed as bio-based thermal insulation for building envelopes. Mixed Polish sheep wool was washed, mechanically opened, and formed into nonwoven mats, then impregnated with either neat or flame-retardant novolac resin to obtain lightweight boards with a fiber content of about 50 wt%. Elemental analysis, ICP-OES, FTIR spectroscopy, and laser and electron microscopy were used to evaluate the fiber composition, keratin structure, morphology, and fiber–matrix interfaces. Mechanical performance under three-point bending and shear, differential scanning calorimetry, thermogravimetric analysis, and transient hot-probe thermal-conductivity measurements were applied to link microstructure with functional behavior. Novolac impregnation transformed the compliant wool mat into self-supporting panels, increasing the flexural modulus to the 0.8–1.4 GPa range and flexural strength to approximately 48–52 MPa, while the shear modulus and work to failure rose by more than an order of magnitude relative to the loose wool reference. Thermal conductivity remained in a typical range for natural-fiber insulations (λ = 0.061 W·m⁻¹·K⁻¹ for the wool mat and 0.071–0.074 W·m⁻¹·K⁻¹ for the composites), although higher than that of expanded polystyrene. DSC and TGA confirmed that wool fibers remain thermally stable up to about 200–220 °C, that the novolac resin cures around 140 °C, with typical phenolic reaction enthalpies, and that both formulations generate high char residues of roughly 60–80 wt% at 600 °C under nitrogen, evidencing a strong charring propensity rather than directly quantifying fire resistance. Overall, the results position sheep wool/novolac panels between conventional bio-based insulation and structural composites and highlight their potential as sustainable, circular insulation materials for energy-efficient building envelopes. Full article

Allium aralii Balos, Köse & Sonay sp. nov. (Amaryllidaceae, sect. Codonoprasum) is described as a new species from southeastern Anatolia, Türkiye. The species is morphologically distinguished from its closest relatives—A. euphraticum, A. turcicum subsp. turcicum, A. turcicum subsp. fusciflorum, and A. yilandaghense—by a unique combination of characters: blackish outer bulb tunics, semi-cylindrical solid leaves exceeding the inflorescence, an extremely long persistent two-valved spathe (4.5–28.0 cm), a lax hemispherical inflorescence (3–4 cm diam., 10–70 flowers), a goblet-shaped perigon with dentate inner tepals, exserted bicolored stamens (white at base and apex, purple in the middle), a reticulate-foveate ovary, and verrucate seed ornamentation with undulate anticlinal walls. Seed micromorphology examined by scanning electron microscopy (SEM) further supports species delimitation. Molecular phylogenetic analyses based on nuclear ITS and chloroplast matK sequences place A. aralii within a well-supported clade containing A. turcicum and allied species, corresponding to the eastern Mediterranean lineage of sect. Codonoprasum. ITS genetic distances between A. aralii and its morphologically closest relatives range 0.0632, falling within the typical interspecific range for Allium. The species is known from a single locality in Bozova district (Şanlıurfa) with fewer than 100 mature individuals and is assessed as Critically Endangered (CR) according to IUCN criteria. This discovery highlights southeastern Anatolia as an underexplored center of Allium diversification and underscores the importance of integrative taxonomy for species delimitation within this taxonomically complex group. Full article