Active matter systems are known to drive directed transport and rotation when coupled to passive inclusions. We study the dynamics of a geometrically symmetric inclusion, termed a torquer, in a bath of chiral active Brownian particles. Despite being geometrically symmetric and non-motile, the torquer exhibits persistent rotation due to spatially inhomogeneous torques arising from angularly biased collisions with active particles. This interaction-driven symmetry breaking does not rely on shape anisotropy or external forcing. Through simulations, we identify two distinct regimes of rotation: one dominated by density gradients at low chirality and another by increased impact frequency at high chirality. Our results demonstrate that persistent rotational dynamics can be realised in a symmetric inclusion, from anisotropic interaction with the active bath.

Platelet-rich plasma (PRP) is an innovative tool in regenerative medicine. It is defined as an autologous product obtained by density gradient centrifugation of blood, resulting in a platelet concentrate rich in growth factors. In gynecology, PRP has been used to treat vaginal atrophy, sexual dysfunction, and inflammatory conditions such as vulvar lichen sclerosus. PRP injection into the vulvo-vaginal area is a potential treatment for several conditions; however, treatment methods and applications vary widely across the published literature. To provide an updated synthesis of current evidence on the administration of PRP to the vulva and vagina as a stand-alone technique in a non-surgical outpatient setting, and to identify its main clinical indications. A systematic search of PubMed and Embase was conducted for studies published up to October 2024 using the terms "platelet rich plasma" AND "vaginal" and "platelet rich plasma" AND "vulvar." Eligible studies included human case reports, prospective, and retrospective cohort studies, as well as randomized and non-randomized controlled trials, assessing PRP injections as a stand-alone technique in the vulvo-vaginal area. Extracted data included study design, patient characteristics, indications, PRP preparation and administration protocols, number of sessions, outcomes, and adverse events. Eighteen studies met the inclusion criteria: two randomized controlled trials, 10 single-arm clinical trials, one retrospective cross-sectional study, and five case reports, comprising 480 patients (401 treated with PRP). The most frequent indication was vulvar lichen sclerosus (n = 179), followed by sexual dysfunction (n = 133) and vulvovaginal atrophy (n = 87). Protocols varied in preparation methods, injection techniques, and treatment schedules. Across studies, PRP injections were associated with improvements in symptoms, sexual function, and vaginal health, with few and mild adverse events. Current evidence suggests that PRP injections in the vulvo-vaginal area may offer clinical benefits across several indications, with a favorable safety profile. However, the high variability in protocols, small sample sizes, and methodological limitations preclude definitive conclusions. Further high-quality randomized controlled trials are required to establish standardized protocols and confirm efficacy.

Background: Although there is evidence of a global decline in sperm motility and an increasing frequency of male infertility, there is minimal documentation regarding prospective treatments and techniques to activate and enhance certain sperm parameters to overwhelm male infertility. Objectives: This study used Glycyrrhiza glabra (Gg) and Platelet Rich Plasma (PRP) media to establish a culture medium that aimed to improve sperm function parameters by preparing in vitro men’s semen complaining of asthenoteratozoospermic factor. Materials and methods: Semen samples from 80 participants were investigated in a comparative cross-sectional study. After semen fluid analysis 34 samples were revealed normozoospermia and 46 samples were with asthenoteratozoospermia. Certain sperm parameters and DNA fragmentation index were assessed. PRP and Gg were used as a sperm culture media. Certain sperm parameters and DNA fragmentation index were assessed using World Health Organization 2021 and 1999 guidelines. Results: After activation using the density gradient method and Gg plus PRP, sperm function parameters improved significantly (p<0.001), including increased motility, morphologically normal sperm percentage, and decreased DNA fragmentation index. Conclusion: It is concluded that the density gradient technique with any medium used in the present study revealed a significant improvement in certain sperm parameters and a reduction in DNA fragmentation index.

Abstract This study utilizes fine-resolution measurements from 2019 Saildrone missions in the North Atlantic (30°–50°N), including a winter Gulf Stream crossing (GS-Winter), a summer subtropical gyre transit (NAOcean-Summer), and a fall shelf passage (NAShelf-Fall), to examine scale-dependent surface density variability under varying atmospheric forcing. In situ measurements reveal three forcing regimes: intense in GS-Winter, weak in NAOcean-Summer, and moderate in NAShelf-Fall. Turner-angle and wavelet analyses indicate a systematic scale-dependent transition from temperature-dominated density at scales ≫ 28 km (the first baroclinic Rossby deformation radius) to salinity-dominated structure at submesoscales (∼10 km), sharply pronounced under temperature‐dominated background (GS-Winter) yet weak under salinity‐dominated background (NAShelf-Fall). Surface density variance spectra show steep slopes (−2.6) in GS-Winter, flatter slopes (−1.9) in NAOcean-Summer, and intermediate slopes (∼−2.2) in NAShelf-Fall. These slopes appear inversely related to published kinetic energy spectra, suggesting a contrast between the advective imprint on surface density and active energy conversion. Joint distributions of surface density gradient indicate that wind stress > 1 N m −2 and turbulent heat loss > 600 W m −2 collapse density gradients to the detection limit (∼3 × 10 −5 kg m −4 ), whereas under weaker forcing, a persistent above-noise tail remains. These observations suggest that mixed-layer shear dispersion predominantly drives density gradient erosion, whereas buoyancy-driven compensation likely contributes only marginally—working hypotheses that warrant future validation. The importance of submesoscale salinity structures underscores the need for ∼10-km L-band satellite salinity retrievals to resolve these features and advance our understanding of their influence on mixed-layer dynamics and biogeochemical activities. Significance Statement Surface density gradients at scales of a few kilometers, formed by submesoscale temperature and salinity fronts and filaments, govern how the ocean mixes heat, momentum, and nutrients in the upper ocean, yet remain poorly observed. Using Saildrone fine-scale measurements of sea surface temperature, salinity, wind, and heat flux in winter, summer, and fall North Atlantic regimes, we show that density control shifts from temperature driven at large scales to salinity driven near 10 km. Strong winds and cooling erase sharp fronts, while lighter forcing allows weak fronts to persist, implicating shear-driven mixing. These findings underscore the need for ∼10-km satellite salinity observations to resolve submesoscale fronts and improve models of ocean dynamics and ecosystems.

Abstract There exist unique northeastward counterwind currents (CWCs) over the China shelf seas, subject to the balance between the northeastward alongshore ageostrophic (effective) pressure gradient force (PGF eff , the residual PGF after balancing the Coriolis force) and southwestward surface wind stress forcing. The underlying physics for the formation of the alongshore PGF remains largely ambiguous. We used process-oriented modeling of the China shelf seas to investigate how the alongshore PGF and subsequent CWC form. Driven by a typical alongshore variable density field and wind forcing, our numerical model produced a realistic shelf current structure and CWC. Our results show that the alongshore sea level elevation gradient, induced by an alongshore variable wind, mainly contributed to the PGF, which is consistent with arrested topographic wave theory. However, the wind-induced elevation gradient alone is insufficient to overcome the frictional effects of wind forcing to form the CWC. The alongshore density gradient, due to heterogeneous heating, enhances the PGF because of the steric effect on sea level. The enhanced PGF produced by the density gradient and wind-induced elevation gradient critically forms the CWC. In addition, the seasonally variable density gradient and wind forcing determine the spatiotemporal variability of the CWC. We found that the dominant intrinsic dynamics of the wind and buoyancy forcing are enough to trigger the CWCs, and the shelf’s topographic features further shape the structure of the CWC. The study provides new insights into the formation of CWC, which has been widely observed over the shelves globally.

The linear eigenmodes of kinetic ballooning modes (KBMs) and their associated turbulent transports in reversed magnetic shear (RMS) configurations with impurity ions are numerically studied using a global electromagnetic Landau-fluid model. Linear eigenmode analysis reveals that the eigenstructure of KBM is predominantly localized near the minimum safety factor q min region for the low toroidal number n mode. While, the ballooning structure becomes more pronounced in the positive shear region for high n mode. Due to the large mass number of the impurity ions, both of the linear growth rate and mode frequency of dominated KBM in the presence of impurity ions with relatively weak density gradient are a bit smaller than those without impurity ions. A distinct phase difference between bulk ion and impurity ion density perturbations is observed on the low-field side. The discontinuous mode structure of KBM density perturbations in RMS configurations leads to corresponding discontinuities in radial density flux profiles. Despite impurity ions have stabilizing effect on linear growth rates of KBM in the case of weak impurity density gradients, nonlinear transport level remains higher than that in the impurity-free case. The intermittent transports of impurity particle and heat can be clearly obtained, when the impurity density gradient is near the impurity peaking factor threshold. When the initial impurity density gradient deviates from the peaking factor threshold, turbulent transport will still transitions into an intermittent regime following a relaxation phase, accompanying with small-scale corrugations of impurity density profile.

Structural, electronic, and thermodynamic characterization with spectroscopic, topological, reactivity, and molecular docking studies of diallyl sulfide.

Magnetic-activated cell sorting non-apoptotic sperm selection improves DNA fragmentation and reproductive outcomes: systematic review and meta-analysis.

Red blood cell-derived extracellular vesicles (RBC-EVs) are emerging as promising biomaterials for next-generation drug delivery, owing to their intrinsic biocompatibility, immune-evasion properties, and minimal oncogenic risk. However, their broader application is currently limited by unresolved challenges related to heterogeneity, reproducibility, and long-term storage stability. By combining discontinuous sucrose density gradient separation with high-resolution interferometric nanoparticle tracking analysis, we identified a sharp bimodal size distribution of vesicles in freshly prepared samples. We then tracked how long-term storage at -80 °C drove their conversion into a monomodal distribution. To reproduce these conditions in a shorter time frame, we developed an "accelerated-ageing" protocol based on freeze-thaw cycles that generates RBC-EV samples with homogeneous density, size distribution, and biological activity, effectively replicating the properties of preparations stored for six months at -80 °C. This new vesicle population remains stable and retains membrane integrity and cellular internalization capacity, as confirmed by surface-associated enzymatic activity assays and uptake tests in cancer cell lines. These results suggest that freezing-induced "accelerated ageing" represents an effective method for the optimization and standardization of RBC-EVs as building blocks for biomaterial and bioengineering applications.

Establishment and application of efficient protoplast isolation and transformation system from leaves of multi-genotype poplars.

Ultrasound-assisted one-step extraction of safflower red and yellow pigments by natural ternary deep eutectic solvents: Extraction optimization and mechanism, separation and biological activities of pigments.

Abstract Two-dimensional (2D) estimates of the upper-ocean vertical velocity w have been commonly performed based on single hydrographic distance–depth sections. However, biases of these estimates have seldom been investigated. We conduct such an investigation employing a 2-month dataset (including temperature, salinity, and horizontal velocity) at a typical front, the Almeria–Oran Front in the Mediterranean Sea, which was collected by a glider fleet piloted in parallel across-front sections. Specifically, using daily objective maps constructed from the dataset, we perform three-dimensional (3D) and 2D estimates of the balanced w ( w 3D and w 2D ) through the quasigeostrophic omega equation and evaluate w 2D against w 3D justified previously. Results show a significantly biased w 2D that is estimated assuming a straight front without curvature. Generally, in the 400-m upper ocean, w 2D and w 3D have a weak spatial correlation of 0.4–0.6; w 2D also presents a notably different magnitude, less than 50% of w 3D (even less than 20% in many cases). We find a pronounced curvature-induced shearing deformation (of horizontal density gradients by geostrophic flows) effect destroying the geostrophic balance and so is the associated w to restore the balance; precluding this effect in w 2D leads to the biases. These biases are also analyzed using the potential vorticity conservation principle: As the curvature causes the across-section vorticity advection, water parcels advected by the across-section flow change their vorticity; they have to be vertically compressed/stretched, requiring w that is neglected in w 2D . Therefore, the biased w 2D may be insufficient for understanding the vertical heat transport and its impact on the climate system. Significance Statement The difficulty of directly measuring ocean vertical motion ( w ), which is weak but plays a crucial role in regulating Earth’s climate, has necessitated the indirect estimation of w from observable variables. The distance–depth two-dimensional (2D) estimate has been a common procedure based on a hydrographic section. However, the bias of this procedure has seldom been examined. We perform such an examination using a 2-month in situ dataset at a frontal site. The 2D estimate ( w 2D ) is found to be significantly biased in both distribution and magnitude due to the neglect of frontal curvature, indicating that w 2D may be insufficient for understanding vertical transports of heat and biogeochemical tracers, as well as their impacts on the climate system and marine ecosystem.

Comprehensive PCM and QM/MM-MD investigation of absorption and emission properties in N-methylindoles.

Abstract Recent studies suggest that the anisotropy in cosmic-ray (CR) arrival directions can provide insight into local acceleration sites and propagation conditions. We developed a unified framework to interpret both the observed energy spectra and the large-scale anisotropy. In this work, we explore the influence of the Sun’s motion relative to the local plasma frame—the Compton–Getting (CG) effect—on the anisotropy. We find that incorporating the CG effect could slightly reduce the dipole amplitude and shift the phase away from the direction of the local regular magnetic field at tens of TeV. At lower energies, where the anisotropy from the CR density gradient is weak, the Sun’s relative motion becomes more prominent. Below ∼200 GeV, the dipole amplitude increases again, approaching the value expected from the CG effect. Additionally, a phase flip is observed at a few hundred GeV, aligning with the CG direction. Future anisotropy measurements from 100 GeV to TeV energies could serve as a critical test of this effect.

Strategy comparison for purifying phycocyanin from microplastic-contaminated Spirulina platensis: A dual evaluation of product quality and microplastic removal.

Integrated experimental, computational and machine learning approaches for the development of Apremilast-Aceclofenac coamorphous systems.

Background: Early SARS-CoV-2 publications revealed methodological gaps that may reflect broader limitations within virology. This review evaluates key experimental domains to assess whether current practices consistently meet foundational standards. Methods: A multi-platform search strategy was performed using academic databases and AI-assisted literature interrogation. Three methodological areas were examined: isolation and purification of viral particles, genome sequencing directly from purified virions without amplification or cloning and infectivity assays using fully composition-matched negative controls. Iterative queries with increasingly strict requirements were used to identify studies meeting these criteria. Results: No publicly accessible studies were found that simultaneously fulfilled the criteria for complete purification, direct genome sequencing and rigorously matched negative controls. Purification methods using density gradients were documented and allow structural characterization, but do not establish exogeneity or pathogenicity. Sequencing directly from purified virions was identified only for certain giant viruses and bacteriophages, while most studies relied on PCR or bacterial cloning. Infectivity research consistently lacked negative controls matched for medium composition and experimental conditions, including in both historical and contemporary studies. Conclusion: These findings indicate persistent gaps between expected methodological standards and current empirical practices in virology. Strengthening experimental rigor particularly through direct sequencing of purified particles, the use of fully composition-matched controls, transparent reporting and independent replication is essential for improving the reliability of viral characterization. A concise summary of key methodological findings is presented in the conclusions section for direct reference.

Aim: Small extracellular vesicles (sEVs) are membrane-bound nanoparticles secreted by virtually all cell types that have emerged as promising sources of protein biomarkers for a wide range of diseases, including central nervous system disorders. Blood sampling is the most informative and non-invasive biomarker source. Notably, mouse models represent essential systems for studying in vivo disease mechanisms and testing therapeutic strategies. Therefore, in this study, we investigated the suitability of two different isolation methods for sEV recovery starting from non-terminal mouse blood sampling, with the aim of identifying the most effective protocol for downstream biomarker discovery. Methods: We performed and compared size exclusion chromatography (SEC) and ultracentrifugation followed by iodixanol density gradient (UC-IDG). Additionally, we optimized extracellular vesicle (EV) isolation from small-volume samples of both serum and plasma, since these represent the most used sources for in vivo preclinical biomarker research. Both methods were evaluated in terms of yield, purity, and EV protein content by nanoparticle tracking analysis, electron microscopy, and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) proteomics. Results: SEC showed a higher number of isolated vesicles and EV-associated markers, while reporting a reduced percentage of blood-abundant co-isolated proteins, compared to UC-IDG. The use of plasma as a starting material resulted in a cleaner background, showing fewer protein aggregates. The obtained results emphasize the advantage of SEC in enhancing vesicle yield and purity levels. Conclusion: This work contributes to sEV-derived biomarker research in mouse models by confirming plasma, rather than serum, as the most reliable source of EVs and providing evidence that SEC is more suitable than UC-IDG for EV isolation.

Abstract Subauroral ion drift (SAID) is a narrow and rapid westward ion flow observed in the subauroral ionosphere during geomagnetic storms and substorms. It is more localized and intense than subauroral polarization streams (SAPS), typically appearing equatorward of auroral boundaries and often associated with midlatitude troughs. This study analyzes ion drifts and plasma density variations using DMSP F16, F17, and F18 data from June 1, 2013, in the Southern Hemisphere. Using multi-satellite observations from three DMSP spacecraft, we systematically examine the spatiotemporal evolution of a SAID event and its associated midlatitude troughs, focusing on their relation to geomagnetic storm phases and substorm activity. We develop an ad hoc empirical model that reproduces SAID spatial distribution and temporal evolution by establishing a quantitative relationship between SAID velocity and the AE index. From the results, we present two key findings: first, we identified a previously unreported two-stage development pattern of SAID: equatorward expansion with minimal width change and moderate potential drop in the early main phase, followed by latitudinal stabilization, width variation, and stronger electric fields in the late main phase. Second, we newly identified that the midlatitude trough developed through three distinct stages: mild density gradient associated with the initial AE increase, sharp density drop at the plasmapause boundary after the first AE decrease, and persistent deep trough after first AE peak and throughout the second AE peak lasted for three hours. These findings and our empirical modeling approach provide new quantitative insights into the distinct temporal evolution patterns of SAID and midlatitude troughs, advancing further understanding of the connection between ionospheric disturbances and geomagnetic storms. Graphical Abstract

BackgroundSperm chromosomes are nonrandomly organized in the cell nucleus, which plays an important role in the regulation of early embryo development, which is determined by the specific localization of sperm chromosomal regions carrying genes with expression crucial at the first contact with ooplasm during fertilization. Thus, the aim of this study is to determine whether the application of selective methods providing high-quality spermatozoa with good motility and/or morphology can increase the frequency of gametes with a specific positioning of chromosomes. For the first time, we used a sequential staining algorithm for consecutive analyses of the same individual spermatozoon with a fixed position, what enables one to achieve full and detailed documentation at the single cell level.MethodsSemen samples from five normozoospermic males were collected and processed for fractionation via swim up (to select viable and motile spermatozoa) or Percoll density gradient (90%/47%; to select viable sperm with normal motility and morphology). Sperm chromatin protamination was assessed by Aniline Blue (AB) staining, and DNA fragmentation by Acridine Orange (AO) (ssDNA fragmentation) or terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay (ssDNA and dsDNA fragmentation). Then, sequential staining and analyses of the same individual spermatozoon with a fixed position on a slide were performed, in the following order: (i) fluorescence in situ hybridization (FISH) for determination of positioning of chromosomal centromeres: 4, 7, 8, 9, 18, X, and Y, with so-called linear and radial estimations applied, followed by distance measurements between selected pairs of chromosomes; and (ii) immunofluorescent (IF) measurement of global sperm DNA methylation (5mC) and hydroxymethylation (5hmC) levels, which added additional data about the epigenetic layer of the sperm chromosomes’ positioning.ResultsOur study demonstrated that high-quality sperm selection methods significantly: (i) increased the frequency of spermatozoa with good chromatin protamination (+ ~25%) and 5mC and 5hmC DNA levels (+ ~9.5%) and (ii) reduced the rate of spermatozoa with ssDNA fragmentation (− ~65%). Motile and morphologically normal spermatozoa showed distinct chromosome repositioning with sex chromosomes shifted to the nuclear periphery, a key chromosomal region of the initial interaction with the ooplasm during fertilization process. Evaluated autosomes revealed various patterns of repositioning.ConclusionsOur findings underline the validity of methods used for selection of high-quality spermatozoa in assisted reproductive technologies (ART), also in the context of the sperm chromosomal topology and chromatin integrity, crucial at the first steps during fertilization.Supplementary InformationThe online version contains supplementary material available at 10.1186/s11658-025-00830-7.