A two-dimensional calibration for resolving nano-positioner pedestal micro-deformation crosstalk.

This paper proposes a two-dimensional calibration method for resolving the nano-positioner pedestal micro-deformation crosstalk errors during the auction process. This refinement aims to enhance the nano-positioner's accuracy and reduce coupling crosstalk errors. The reaction force exerted by the piezoelectric actuator can cause micro-deformation in the nano-positioner sensor pedestal, causing substantial errors in uncalibrated closed-loop control. This phenomenon has been previously overlooked. According to the two-degree of freedom parallel-symmetric decoupled nano-positioner deformation characteristics, a two-dimensional calibration matrix is proposed to suppress the crosstalk between two axes caused by the micro-deformation of the sensor pedestal. Experimental results show that the calibrated closed-loop system reduces X-axis and Y-axis coupling crosstalk errors to 1/67th and 1/18th of the uncalibrated closed-loop system, respectively, concurrently enhancing the positioning accuracy to 11.8 and 17 times that of the uncalibrated closed-loop system. The calibrated closed-loop feedback control method proposed in this paper proves effective for all compact nano-positioners with pedestal deformation issues. This research provides a crucial reference for the design of nano-positioners, offering insights into enhancing their accuracy and mitigating crosstalk issues.

CRISPR/Cas12a-coupled multiplexed strand displacement amplification for miRNA155 one-tube detection: via a dual-cavity PCR tube.

A CRISPR/Cas12a-coupled multiplexed strand displacement amplification (CMSDA) for the detection of miR155 has been developed. Non-specific amplification was avoided by designing a single-stranded DNA template with a hairpin structure. The detection target miR155 was used as a primer to initiate a multiple-strand displacement reaction to produce abundant ssDNA. ssDNA was recognized by the Cas12a/CrRNA binary complex, activating the trans-cleaving activity of Cas12a. The multiple-strand displacement reaction is more efficiently detected compared with a single-strand displacement reaction. The detection range is from 250 pM to 1 nM, and the limit of the detection is 6.5 pM. The proposed method showed a good applicability in complex serum environments, indicating that the method has a broad prospect for disease detection and clinical application. In addition, we designed a dual-cavity PCR tube, which realized one-tube detection of miRNA155 and avoided open-cap contamination.

Ultrasound-assisted deep eutectic solvents extraction of polysaccharides from Loquat leaf: Process optimization and bioactivity study.

Loquat leaves are the by-product of loquat fruit production. Polysaccharides are one of the main active ingredients in loquat leaves. In this study, polysaccharides were extracted from loquat leaves by ultrasonic-assisted deep eutectic solvents (DESs) extraction method. Further, the extracted crude loquat leaf polysaccharides (CLLP) were purified and separated via S-8 resin and DEAE-52 cellulose column chromatography, respectively. Additionally, the effects of polysaccharides on activity of sperm in boar semen preserved in medium at 17 °C, were evaluated preliminarily. DES, composed of choline chloride/ethylene glycol (1:6, molar ratio), was proved to be the suitable solvent for LLP extraction. The optimized extraction conditions were water content 44 %, liquid-solid ratio 1:29 (g/g), extraction temperature 61 °C and extraction time 98 min. Under these conditions, the LLP yield was 57.82 ± 1.50 mg/g. A homogeneous polysaccharide (LLP1-2, Mw: 2.17 × 104 Da) was isolated from CLLP. Its total sugar, uronic acid and protein contents were 76.31 ± 1.25 %, 14.19 ± 0.67 % and 3.28 ± 0.42 %, respectively. Further, 800 µg/mL LLP1-2 could effectively enhance the antioxidant activity of sperm. This study laid a foundation for DESs and column chromatography in the field of polysaccharide extraction and separation, proving that LLP can be used as a natural antioxidant for sperm preservation.

Targeting ferroptosis as a potential strategy to overcome the resistance of cisplatin in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is a crucial public health problem, accounting for approximately 2% of all cancers globally and 90% of oral malignancies over the world. Unfortunately, despite the achievements in surgery, radiotherapy, and chemotherapy techniques over the past decades, OSCC patients still low 5-year survival rate. Cisplatin, a platinum-containing drug, serves as one of the first-line chemotherapeutic agents of OSCC. However, the resistance to cisplatin significantly limits the clinical practice and is a crucial factor in tumor recurrence and metastasis after conventional treatments. Ferroptosis is an iron-based form of cell death, which is initiated by the intracellular accumulation of lipid peroxidation and reactive oxygen species (ROS). Interestingly, cisplatin-resistant OSCC cells exhibit lower level of ROS and lipid peroxidation compared to sensitive cells. The reduced ferroptosis in cisplatin resistance cells indicates the potential relationship between cisplatin resistance and ferroptosis, which is proved by recent studies showing that in colorectal cancer cells. However, the modulation pathway of ferroptosis reversing cisplatin resistance in OSCC cells still remains unclear. This article aims to concisely summarize the molecular mechanisms and evaluate the relationship between ferroptosis and cisplatin resistance OSCC cells, thereby providing novel strategies for overcoming cisplatin resistance and developing new therapeutic approaches.

Target-mediated rolling circle transcription coupling with CRISPR/Cas12a-Cas13a for simultaneous detection of HPV16 and HPV18.

Simultaneous detection of multiple targets can provide important data support for clinical diagnosis and treatment. Here, we report a facile isothermal assay based on target-mediated rolling circle transcription coupling with CRISPR/Cas12a-Cas13a (TM-RCT/Cas12a-Cas13a). Through facile one-step amplification (TM-RCT), two target DNAs are converted to RNA amplified products. The simultaneous detection of HPV16 and HPV18 is then achieved by combining two CRISPR/Cas systems. This system shows excellent sensing performance and provides a universal method for simultaneous detection.

Whole-brain imaging of freely-moving zebrafish.

One of the holy grails of neuroscience is to record the activity of every neuron in the brain while an animal moves freely and performs complex behavioral tasks. While important steps forward have been taken recently in large-scale neural recording in rodent models, single neuron resolution across the entire mammalian brain remains elusive. In contrast the larval zebrafish offers great promise in this regard. Zebrafish are a vertebrate model with substantial homology to the mammalian brain, but their transparency allows whole-brain recordings of genetically-encoded fluorescent indicators at single-neuron resolution using optical microscopy techniques. Furthermore zebrafish begin to show a complex repertoire of natural behavior from an early age, including hunting small, fast-moving prey using visual cues. Until recently work to address the neural bases of these behaviors mostly relied on assays where the fish was immobilized under the microscope objective, and stimuli such as prey were presented virtually. However significant progress has recently been made in developing brain imaging techniques for zebrafish which are not immobilized. Here we discuss recent advances, focusing particularly on techniques based on light-field microscopy. We also draw attention to several important outstanding issues which remain to be addressed to increase the ecological validity of the results obtained.

From perception to behavior: The neural circuits underlying prey hunting in larval zebrafish.

A key challenge for neural systems is to extract relevant information from the environment and make appropriate behavioral responses. The larval zebrafish offers an exciting opportunity for studying these sensing processes and sensory-motor transformations. Prey hunting is an instinctual behavior of zebrafish that requires the brain to extract and combine different attributes of the sensory input and form appropriate motor outputs. Due to its small size and transparency the larval zebrafish brain allows optical recording of whole-brain activity to reveal the neural mechanisms involved in prey hunting and capture. In this review we discuss how the larval zebrafish brain processes visual information to identify and locate prey, the neural circuits governing the generation of motor commands in response to prey, how hunting behavior can be modulated by internal states and experience, and some outstanding questions for the field.

fmr1 Mutation Alters the Early Development of Sensory Coding and Hunting and Social Behaviors in Larval Zebrafish.

Autism spectrum disorders (ASDs) are developmental in origin; however, little is known about how they affect the early development of behavior and sensory coding. The most common inherited form of autism is Fragile X syndrome (FXS), caused by a mutation in FMR1 Mutation of fmr1 in zebrafish causes anxiety-like behavior, hyperactivity, and hypersensitivity in auditory and visual processing. Here, we show that zebrafish fmr1-/- mutant larvae of either sex also display changes in hunting behavior, tectal coding, and social interaction. During hunting, they were less successful at catching prey and displayed altered behavioral sequences. In the tectum, representations of prey-like stimuli were more diffuse and had higher dimensionality. In a social behavioral assay, they spent more time observing a conspecific but responded more slowly to social cues. However, when given a choice of rearing environment fmr1-/- larvae preferred one with reduced visual stimulation, and rearing them in this environment reduced genotype-specific effects on tectal excitability. Together, these results shed new light on how fmr1-/- changes the early development of neural systems and behavior in a vertebrate.SIGNIFICANCE STATEMENT Autism spectrum disorders (ASDs) are caused by changes in early neural development. Animal models of ASDs offer the opportunity to study these developmental processes in greater detail than in humans. Here, we found that a zebrafish mutant for a gene which in humans causes one type of ASD showed early alterations in hunting behavior, social behavior, and how visual stimuli are represented in the brain. However, we also found that mutant fish preferred reduced visual stimulation, and rearing them in this environment reduced alterations in neural activity patterns. These results suggest interesting new directions for using zebrafish as a model to study the development of brain and behavior in ASDs, and how the impact of ASDs could potentially be reduced.

Role of magnesium-doped calcium sulfate and ß-tricalcium phosphate composite ceramics in macrophage polarization and osteo-induction.

In the current study, we explored the role of Mg2+-doped CaSO4/ß-TCP composite biopolymer in regulating macrophage polarization and its relation with enhanced osteogenic differentiation of periodontal ligament stem cells. Furthermore, mechanism underling the regulation of macrophage polarization by CaSO4/ß-TCP was evaluated. Mg2+-doped CaSO4/ß-TCP composite was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Macrophage polarization was characterized using flow cytometry analysis. Macrophage morphometric analysis was conducted by FITC phalloidin staining. Western blot and qRT-PCR assays were used to assess gene expression levels and miRNAs, respectively. SEM morphology of CaSO4/ß-TCP ceramic revealed a particle size of 10-50 µm, and XRD spectrum showed that characteristic peak of samples was consistent with that of CaSO4 and ß-TCP. Results from flow cytometry evidenced significant upregulation of M2 macrophage markers after adding ceramic biopolymer, indicating the induction of inactivated M0 macrophage polarization to M2 macrophage. Macrophage morphometric analysis revealed development of lamellar pseudopodia on day 7 in CaSO4/ß-TCP group. Furthermore, flow cytometry revealed high positivity rate of 90.34% (CD44) and 89.36% (CD146). qRT-PCR results showed that the level of miR-21-5p was significantly decreased in M2 macrophages. Moreover, western blot analysis revealed upregulated expression levels of RUNX2, osterix (Osx), and osteopontin (OPN), and ELISA exhibited increase in cytokine levels (IL-1ß, IL-10, TGF-ß1, and BMP-2) in the presence of macrophages, indicating the osteogenic differentiation ability of periodontal ligament stem cells. The study evidenced the regulation of macrophage polarization by Mg2+-doped CaSO4/ß-TCP composite ceramic and its mediation through lncRNA PVT1/miR-21-5p/smad2 molecular axis.

Distribution, sources, and ecological risk assessment of polycyclic aromatic hydrocarbons (PAHs) in the tidal creek water of coastal tidal flats in the Yellow River Delta, China.

The concentrations, distribution, sources and ecological risk levels of polycyclic aromatic hydrocarbons (PAHs) in tidal creek water from coastal tidal flats of the Yellow River Delta were investigated. The concentrations of 16 PAHs ranged from 0.113 to 1.533, with a mean value of 0.496 ± 0.035 µg L-1, which indicated a moderate level of pollution. The main long-term sources of PAHs in the coastal tidal flats of the Yellow River Delta were petroleum combustion and petroleum pollution. The ecological risk assessment showed that the levels of PAHs in tidal creek water of the coastal tidal flats in the Yellow River Delta corresponded to medium to high ecological risk levels, and a high probability of potential ecological risk, posing harm to aquatic organisms. Among the 7 sampling sites, site 5, site 6, and site 7 were at high ecological risk, and the other sites were at moderate ecological risk. PAH pollution in the tidal creek water near the Yellow River Estuary and farther south, in the coastal tidal wetland of Laizhou Bay, deserves special attention, especially with respect to the prevention and control of benzo[a]pyrene (BaP) pollution in the water.

Spontaneous and evoked activity patterns diverge over development.

The immature brain is highly spontaneously active. Over development this activity must be integrated with emerging patterns of stimulus-evoked activity, but little is known about how this occurs. Here we investigated this question by recording spontaneous and evoked neural activity in the larval zebrafish tectum from 4 to 15 days post-fertilisation. Correlations within spontaneous and evoked activity epochs were comparable over development, and their neural assemblies refined in similar ways. However, both the similarity between evoked and spontaneous assemblies, and also the geometric distance between spontaneous and evoked patterns, decreased over development. At all stages of development, evoked activity was of higher dimension than spontaneous activity. Thus, spontaneous and evoked activity do not converge over development in this system, and these results do not support the hypothesis that spontaneous activity evolves to form a Bayesian prior for evoked activity.

Behavioral Signatures of a Developing Neural Code.

During early life, neural codes must develop to appropriately transform sensory inputs into behavioral outputs. Here, we demonstrate a link between the maturity of neural coding in the visual brain and developmental changes in visually guided behavior. In zebrafish larvae, we show that visually driven hunting behavior improves from 4 to 15 days post-fertilization, becoming faster and more accurate. During the same period, population activity in parts of the optic tectum refines, improving decoding and information transmission for particular spatial positions. Remarkably, individual differences in decoding can predict each fish's hunting success. Together, these results help reveal how the neural codes required for a natural behavior emerge during development.

A unique meadow of the marine angiosperm Zostera japonica, covering a large area in the turbid intertidal Yellow River Delta, China.

Marine submerged aquatic angiosperms (seagrasses) are declining globally. The species Zostera japonica Asch. & Graebn. is endangered in its native range in Asia, but has been successfully introduced to North America. A large area (1031.8 ha) of Z. japonica meadow has recently been discovered in the intertidal zone of Yellow River Delta, China. This seagrass occurs along both sides of the river mouth, forming dense meadows in turbid water conditions. Seasonal investigations over two years were conducted to examine the distribution, biomass, seed reproduction, seed bank, and population recruitment of the seagrass meadows at three sites in the intertidal zone. The meadows generally showed relatively high coverage, biomass, reproductive effort, and seed production in August. The seed bank was found to be large and contributed to population recruitment. There were significant inter-annual variations overall, and at individual sites. These variations are likely due to winter temperatures, which determine the abundance of overwintering shoots and seedling success. Differences in micro-topography may also play a role in producing variations in seedling success between sites. Microsatellite analysis revealed a high genetic exchange between the two sides of the river mouth. The results indicate that the seagrass bed in the Yellow River Delta shallow waters is in good condition, which can be attributed to its location within a national nature reserve. Establishment of protected areas might act as an effective way to mitigate the anthropogenic disturbance, conserve the seagrass meadows, and then enhance critical ecosystem functions.

Sensitivity to Vocalization Pitch in the Caudal Auditory Cortex of the Marmoset: Comparison of Core and Belt Areas.

Based on anatomical connectivity and basic response characteristics, primate auditory cortex is divided into a central core surrounded by belt and parabelt regions. The encoding of pitch, a prototypical element of sound identity, has been studied in primary auditory cortex (A1) but little is known about how it is encoded and represented beyond A1. The caudal auditory belt and parabelt cortical fields process spatial information but also contain information on non-spatial aspects of sounds. In this study, we examined neuronal responses in these areas to pitch-varied marmoset vocalizations, to derive the consequent representation of pitch in these regions and the potential underlying mechanisms, to compare to the encoding and representation of pitch of the same sounds in A1. With respect to response patterns to the vocalizations, neurons in caudal medial belt (CM) showed similar short-latency and short-duration response patterns to A1, but caudal lateral belt (CL) neurons at the same hierarchical level and caudal parabelt (CPB) neurons at a higher hierarchical level showed delayed or much delayed response onset and prolonged response durations. With respect to encoding of pitch, neurons in all cortical fields showed sensitivity to variations in the vocalization pitch either through modulation of spike-count or of first spike-latency. The utility of the encoding mechanism differed between fields: pitch sensitivity was reliably represented by spike-count variations in A1 and CM, while first spike-latency variation was better for encoding pitch in CL and CPB. In summary, our data show that (a) the traditionally-defined belt area CM is functionally very similar to A1 with respect to the representation and encoding of complex naturalistic sounds, (b) the CL belt area, at the same hierarchical level as CM, and the CPB area, at a higher hierarchical level, have very different response patterns and appear to use different pitch-encoding mechanisms, and (c) caudal auditory fields, proposed to be specialized for encoding spatial location, can also contain robust representations of sound identity.

Distributed representation of vocalization pitch in marmoset primary auditory cortex.

The pitch of vocalizations is a key communication feature aiding recognition of individuals and separating sound sources in complex acoustic environments. The neural representation of the pitch of periodic sounds is well defined. However, many natural sounds, like complex vocalizations, contain rich, aperiodic or not strictly periodic frequency content and/or include high-frequency components, but still evoke a strong sense of pitch. Indeed, such sounds are the rule, not the exception but the cortical mechanisms for encoding pitch of such sounds are unknown. We investigated how neurons in the high-frequency representation of primary auditory cortex (A1) of marmosets encoded changes in pitch of four natural vocalizations, two centred around a dominant frequency similar to the neuron's best sensitivity and two around a much lower dominant frequency. Pitch was varied over a fine range that can be used by marmosets to differentiate individuals. The responses of most high-frequency A1 neurons were sensitive to pitch changes in all four vocalizations, with a smaller proportion of the neurons showing pitch-insensitive responses. Classically defined excitatory drive, from the neuron's monaural frequency response area, predicted responses to changes in vocalization pitch in <30% of neurons suggesting most pitch tuning observed is not simple frequency-level response. Moreover, 39% of A1 neurons showed call-invariant tuning of pitch. These results suggest that distributed activity across A1 can represent the pitch of natural sounds over a fine, functionally relevant range, and exhibits pitch tuning for vocalizations within and outside the classical neural tuning area.

Tolerance of Ruppia sinensis Seeds to Desiccation, Low Temperature, and High Salinity With Special Reference to Long-Term Seed Storage.

Seeds are important materials for the restoration of globally-threatened marine angiosperm (seagrass) populations. In this study, we investigated the differences between different Ruppia sinensis seed types and developed two feasible long-term R. sinensis seed storage methods. The ability of R. sinensis seeds to tolerate the short-term desiccation and extreme cold had been investigated. The tolerance of R. sinensis seeds to long-term exposure of high salinity, cold temperature, and desiccation had been considered as potential methods for long-term seed storage. Also, three morphological and nine physiological indices were measured and compared between two types of seeds: Shape L and Shape S. We found that: (1) wet storage at a salinity of 30-40 psu and 0°C were the optimal long-term storage conditions, and the proportion of viable seeds reached over 90% after a storage period of 11 months since the seeds were collected from the reproductive shoots; (2) dry condition was not the optimal choice for long-term storage of R. sinensis seeds; however, storing seeds in a dry condition at 5°C and 33 ± 10% relative humidity for 9 months had a relatively high percentage (74.44 ± 2.22%) of viable seeds, consequently desiccation exposure could also be an acceptable seed storage method; (3) R. sinensis seeds would lose vigor in the interaction of extreme cold (-27°C) and desiccation; (4) there were significant differences in seed weight, seed curvature, and endocarp thickness between the two types of seeds. These findings provided fundamental physiological information for R. sinensis seeds and supported the long-term storage of its seeds. Our results may also serve as useful reference for seed storage of other threatened seagrass species and facilitate their ex situ conservation and habitat restoration.

Effects of temperature and salinity on Ruppia sinensis seed germination, seedling establishment, and seedling growth.

As typical submerged aquatic vegetation, Ruppia species are facing population reductions due to anthropogenic impacts. In this study, we investigated the effects of temperature and salinity on seed germination and seedling establishment of Ruppia sinensis seeds collected from northern China. The effects of seven salinities (0-50) and six water temperatures (0-30°C) on seed germination were investigated to identify the environmental conditions that could potentially limit survival and growth. We found that: 1) optimum seed germination was salinity 5 at 30°C; 2) high salinity (salinity 40-50) and low temperature (0°C) significantly inhibited seed germination; 3) seed germination with increasing temperature showed a bimodal pattern at suitable salinities (5-10); 4) storing seeds at high salinities (40-50) or low temperature (0°C) promoted germination after transferal to optimal germination conditions. These findings may serve as useful information for R. sinensis habitat establishment and restoration programs.

Habitat-dependent changes in vigilance behaviour of Red-crowned Crane influenced by wildlife tourism.

The Endangered Red-crowned Crane (Grus japonensis) is one of the most culturally iconic and sought-after species by wildlife tourists. Here we investigate how the presence of tourists influence the vigilance behaviour of cranes foraging in Suaeda salsa salt marshes and S. salsa/Phragmites australis mosaic habitat in the Yellow River Delta, China. We found that both the frequency and duration of crane vigilance significantly increased in the presence of wildlife tourists. Increased frequency in crane vigilance only occurred in the much taller S. salsa/P. australis mosaic vegetation whereas the duration of vigilance showed no significant difference between the two habitats. Crane vigilance declined with increasing distance from wildlife tourists in the two habitats, with a minimum distance of disturbance triggering a high degree of vigilance by cranes identified at 300 m. The presence of wildlife tourists may represent a form of disturbance to foraging cranes but is habitat dependent. Taller P. australis vegetation serves primarily as a visual obstruction for cranes, causing them to increase the frequency of vigilance behaviour. Our findings have important implications for the conservation of the migratory red-crowned crane population that winters in the Yellow River Delta and can help inform visitor management.

Expression, purification and characterization of a novel recombinant SVTLE, r-agkihpin-2, from Gloydius halys Pallas venom gland in Escherichia coli.

In our previous work, a thrombin-like enzyme (TLE), agkihpin, was successfully isolated, purified, cloned and named from the venom of Gloydius halys Pallas, having fibrinolytic, fibrinogenolytic and thrombosis-reduced activities, attenuating migration of liver cancer cell, and without bleeding risk. To explore the possibility of agkihpin as a thrombolytic and/or anti-metastasis agent in the future, in this study recombinant agkihpin was expressed and purified in Escherichia coli, and its biological activities investigated. Thus, r-agkihpin-2 was successfully expressed and purified and confirmed by Western blot and peptide mass fingerprinting. After purification and renaturation, 46 mg (399 U) of active r-agkihpin-2 was obtained from 1 L bacterial culture. The results of the arginine esterase activity assay, fibrin plate test fibrinogenolytic activity assay, thrombin-induced venous thrombosis assay, Scratch-Wound assay and bleeding assay showed that active r-agkihpin-2 had slightly lower TAME hydrolytic, fibrinolytic, fibrinogenolytic, thrombus-reduced and migration-attenuated activities than those of native agkihpin, and had no bleeding risk. These findings confirmed that, active r-agkihpin-2 could be further investigated for thrombolytic and/or anti-metastasis drug discovery in the future.