Search Results (442)

Flapping-Wing Aerial Vehicles (FWAVs), which take inspiration from the flight of birds and insects, have gained increasing attention over the past decades due to advantages such as low noise, biomimicry and safety, enabled by the absence of propellers. These features make them particularly suitable for applications in natural environments and operations near humans. However, their complexity introduces significant challenges, including difficulties in take-off and landing as well as limited endurance. Perching represents a promising solution to address these limitations. By equipping these drones with a perching mechanism, they could land on branches to save energy and later exploit the altitude to resume flight without requiring human intervention. Specifically, this review focuses on perching mechanisms based on grasping. It presents designs developed for flapping-wing platforms and complements them with systems originally intended for other types of aerial robots, evaluating their applicability to FWAV applications. The purpose of this work is to provide a structured overview of the existing strategies to support the development of new, effective solutions that could enhance the use of FWAVs in real-world applications. Full article

Traditionally, duct sizing in ventilation systems is based on balancing pressure losses across all branches, with fan selection performed subsequently. However, this sequential approach is inadequate for systems with distributed fans in the central duct network, where pressure losses can vary significantly. Consequently, when designing the system topology, fan placement and duct sizing must be considered together. Recent research has demonstrated that discrete optimisation methods can account for multiple load cases and produce ventilation layouts that are both cost- and energy-efficient. However, existing approaches usually concentrate on component placement and assume that duct sizing has already been finalised. While this is sufficient for later design stages, it is unsuitable for the early stages of planning, when numerous system configurations must be evaluated quickly. In this work, we present a novel methodology that simultaneously optimises duct sizing, fan placement, and volume flow controller configuration to minimise life-cycle costs. To achieve this, we exploit the structure of the problem and formulate a mixed-integer linear program (MILP), which, unlike existing non-linear models, significantly reduces computation time while introducing only minor approximation errors. The resulting model enables fast and robust early-stage planning, providing optimal solutions in a matter of seconds to minutes, as demonstrated by a case study. The methodology is demonstrated on a case study, yielding an optimal configuration with distributed fans in the central fan station and achieving a 5 reduction in life-cycle costs compared to conventional central designs. The MILP formulation achieves these results within seconds, with linearisation errors in electrical power consumption below 1.4%, confirming the approach’s accuracy and suitability for early-stage planning. Full article

The early developmental transition from endogenous to exogenous feeding is a critical period in carnivorous fish larvae, often associated with high mortality rates in aquaculture. Although trypsin, a key protease in protein digestion, is hypothesized to play a pivotal role in initiating exogenous feeding, the expression dynamics and functional contributions of trypsin and isoforms during early development remain poorly characterized in carnivorous species. This study explores the critical role of trypsin in the early feeding process of carnivorous fish, using mandarin fish (Siniperca chuatsi) as a model, which is a commercially valuable species that faces significant challenges during this phase due to its strict dependence on live prey and underdeveloped digestive system. Phylogenetic analysis indicates that, compared to herbivorous and omnivorous fish, carnivorous fish have evolved a greater number of trypsins, with a distinct branch specifically dedicated to try. RNA-seq data revealed the expression profiles of 13 trypsins during the early developmental stages of the mandarin fish. Most trypsins began to be expressed in large quantities with the appearance of the pancreas, reaching a peak prior to feeding. In situ hybridization revealed the spatiotemporal expression pattern of trypsins, starting from the pancreas in early development and later extending to the intestines. Furthermore, inhibition of trypsins activity successfully suppressed early oral feeding in mandarin fish, which was achieved by increasing the expression of cholecystokinin 2 (CCK2) and proopiomelanocortin (POMC) to suppress appetite. These findings enhance our understanding of the adaptive relationship between the ontogeny of the digestive enzyme system and feeding behavior in carnivorous fish. This research may help alleviate bottleneck issues in aquaculture production by improving the survival rate and growth performance of carnivorous fish during critical early life stages. Full article

Horticultural research into the group of plants known as cycads has been deficient, and this includes the study of root growth and function. The form of nitrogen (N) available to plants is known to influence root growth and morphology. The response of cycad roots to N has not been studied to date. Cycas revoluta and Cycas edentata seedlings were grown in hydroponic culture and provided urea, nitrate, or ammonium forms of N. Solutions with all three forms of N increased root growth and branching when compared with nutrient solution devoid of N, with ammonium eliciting the greatest increases. Ammonium increased lateral root length 210% for C. revoluta and 164% for C. edentata. Ammonium decreased specific root length 38% for C. revoluta and 39% for C. edentata. The influence of the N source on stem and leaf growth was minimal. Ammonium increased the root-to-shoot ratio 15% for C. revoluta and 51% for C. edentata, but urea and nitrate did not influence this plant trait. A mixture of nitrate and ammonium generated plant responses that were no different from ammonium alone. The plants supplied with N in the solution produced coralloid root growth that was 14% of the no-N plants for C. revoluta and 22% of the no-N plants for C. edentata. This initial determination of the cycad plant response to the N form indicated that root plasticity was considerable and ammonium stimulated root growth more so than urea or nitrate. Long-term growth studies in mineral soils and nursery container medium are needed to determine if these findings from the hydroponic culture of small seedlings translate to general recommendations for the preferential use of ammonium for cycad culture. Full article

Modification of synthetic oligonucleotides and DNA is widely used in many applications in the life sciences. However, in most cases, modified DNA cannot be restored to its native state. Here, we report the preparation of a thymidine-inosine dimer building block (TID) for oligonucleotide synthesis. The TID modification supports the functionalization of synthetic oligonucleotides, which can later be removed to restore the DNA strand to its native state. The TID unit allows for a wide spectrum of postsynthetic modifications of oligonucleotides through click chemistry, including conjugation with fluorescent tags and small molecules, preparation of branched oligonucleotide scaffolds, and anchoring to a solid support. Due to the modification of the thymine base, the TID unit reduces the stability of the DNA duplex. We found that the negative effect of internal TID modification on duplex stability does not exceed the same for a single base mismatch. As long as the TID modification is present in the DNA strand, it disrupts its natural functionality. The “caging” effect of TID in the template strand with respect to DNA polymerase was demonstrated in primer extension experiments. Traceless removal of the temporary functional group occurs through oxidative cleavage of the inosine subunit, resulting in the formation of a native DNA strand with the thymine base left at the cleavage site. An anthracene-modified dodecamer oligonucleotide and a branched oligonucleotide scaffold were used to study the cleavage of the reporter group or the oligonucleotide side strand, respectively. It was shown that aqueous tetramethylguanidine efficiently cleaves the oxidized inosine subunit of TID at 37 °C, forming the native DNA strand. Full article

Background/Objectives: Both invasive and non-invasive electrical stimulation of the vagus nerve have been studied as potential treatments for neurological conditions, with mixed results. Ultrasonic Vagus Nerve Stimulation (U-VNS), which non-invasively stimulates the auricular branch of the vagus nerve using ultrasound, may offer a more targeted and effective approach than electric currents. To facilitate future clinical trials of U-VNS, this study aimed to (1) investigate the effectiveness of blinding of a U-VNS device versus a sham device and (2) record the type, onset, and duration of any adverse effects resulting from U-VNS. Methods: In this single-blind randomised controlled study, twenty healthy volunteers were randomly assigned to receive either a 30 min session of true U-VNS and a 30 min session of sham stimulation 1 week later, or vice versa. The effectiveness of blinding and the occurrence of adverse effects were measured using self-report questionnaires. Results: James’ Blinding Index showed that blinding using the sham device was highly effective in both the real U-VNS condition, BI = 0.9 (95% CI: 0.7–1.0), and the sham condition, BI = 1.0 (95% CI: 1.0–1.0). The adverse effects reported were mild, transient, and mostly related to sensations on the skin immediately under the transducer of the device. Conclusions: A high level of blinding effectiveness can be achieved for U-VNS by using a sham device. Adverse effects are generally mild and transient. These findings will inform the design of future clinical trials of U-VNS. Full article

The renal vessels are known to exhibit variations in different populations. The present retrospective cross-sectional study aimed to evaluate the radiological anatomy of renal arteries and veins in the Omani population. Computed tomography angiography scans were used to assess diameter, laterality, and vascular branching patterns in adults (aged ≥ 18 years) who underwent contrast-enhanced CT angiography of the abdomen and pelvis between 1 January 2023, and 31 December 2024. Normal CT angiograms of cases performed for vascular pathology screening, renal transplant workup, or trauma evaluation with normal findings were included. Measurements included diameters, anatomical course, and vascular variations in the renal arteries and veins. Accessory renal arteries were defined as any additional arteries arising from the aorta supplying the kidney, regardless of the entry point. The mean diameters of the right and left renal arteries were significantly higher in males (p = 0.020 and 0.026, respectively). The right renal vein was significantly larger in females (p = 0.020). Accessory renal arteries were identified in 24.22% (n = 31 patients), including two cases with unilateral double accessory arteries. The right and left RA diameters were 4.51 ± 0.91 mm and 4.95 ± 0.98 mm, respectively, both significantly larger in males (p = 0.020 and 0.026). Supernumerary renal veins were observed in 21 patients; retroaortic and circumaortic left RVs were found in seven and one case(s), respectively. Venous variations were present in 17.2% of the Omani subjects. The findings may enhance preoperative planning, especially in renal transplantation and urologic surgery, by increasing awareness of anatomical variants. This region-specific dataset supports the development of optimized imaging protocols and surgical strategies for better patient care. Full article

Seasonal dynamics of dissolved organic matter (DOM) in agricultural ditches significantly impact carbon cycling and water quality in connected rivers. This study aimed to characterize seasonal variations in DOM composition and dynamics within hierarchical agricultural ditch systems in Tianjin, northern China. Surface water samples were collected from river channels, main ditches, branch ditches, lateral ditches, and field ditches during wet (June 2021) and dry (December 2021) seasons. DOM characteristics were analyzed using dissolved organic carbon (DOC) quantification, ultraviolet-visible (UV-Vis) absorption spectroscopy, and three-dimensional excitation–emission matrix spectroscopy (3D-EEMs) coupled with parallel factor analysis (PARAFAC). The concentration of DOC in ditch surface water exhibited significant seasonal variations, with significantly higher levels observed during the wet season (Huangzhuang: 6.72 ± 0.7 mg/L; Weixing: 13.15 ± 3.1 mg/L) compared to the dry season (Huangzhuang: 5.93 ± 0.3 mg/L; Weixing: 9.35 ± 2.6 mg/L). Both UV-Vis spectral and EEM-PARAFAC analysis revealed that DOM in ditch systems was predominantly composed of fulvic-like and tryptophan-like components, representing the portion of organic matter in water bodies that is highly biologically active, highly mobile, relatively “fresh”, or “not fully humified”. PARAFAC identified microbial humic-like (C1: wet season 40.36%, dry season 34.42%) and protein-like (C3: wet season 40.3%, dry season 49.87%) components as dominant. DOM sources were influenced by dual inputs from terrestrial and autochthonous origins during the wet season, while primarily deriving from autochthonous sources in the dry season. This study elucidates the advances of spectroscopic techniques in deciphering the composition, sources, and influencing factors of DOM in aquatic systems. The findings support implementing riparian buffer strips and optimized fertilizer management to mitigate seasonal peaks of bioavailable DOM in agricultural ditch systems. Full article

Background: The superior thyroid artery (STA) exhibits significant anatomical variability, which is crucial for head and neck surgical procedures, particularly free flap reconstruction. This systematic review synthesizes the current knowledge on STA origin, branching patterns, perfusion territory, and its relationship with the superior laryngeal nerve (SLN), focusing on implications for flap selection and surgical planning. Methods: A comprehensive search of relevant databases was conducted to identify studies reporting on STA anatomy. Data extraction focused on the STA origin variations, relationships with anatomical landmarks, branching patterns, perfusion territory, and the STA-SLN relationship. Emphasis was placed on variations impacting STA’s suitability as a recipient vessel for free flaps. Data were synthesized qualitatively. Results: The STA most commonly originates from the external carotid artery (ECA), with variations from the carotid bifurcation (CB) and common carotid artery (CCA). Sex-based and laterality differences were noted. Branching patterns varied considerably, influencing perfusion of the thyroid gland, larynx, and adjacent musculature. The STA’s relationship with the external branch of the SLN (EBSLN), classified by Cernea’s classification, highlighted the risk of iatrogenic injury. The STA provides perfusion to the thyroid gland, larynx, sternocleidomastoid muscle, and strap muscles, all of which can be raised as flaps. Conclusions: Understanding STA anatomical variations is essential for surgeons planning free flap reconstruction in the head and neck. This review underscores the importance of preoperative imaging to assess STA suitability as a recipient’s vessel and minimize complications. Further research is needed to quantify the impact of STA variations on free flap outcomes. Full article

Background: Stiff-knee gait commonly involves rectus femoris spasticity in patients with central nervous system lesions. Diagnostic nerve blocks aid in predicting treatment outcomes; however, current techniques may overlook multiple nerve branches that innervate the rectus femoris muscle, potentially resulting in an incomplete assessment of treatment outcomes. Methods: We present an ultrasound-guided approach that we currently use in our practice, using anatomical landmarks, including the femoral artery, the sartorius muscle, and the rectus femoris’ characteristic “J-shaped” internal tendon. The technique employs an “elevator” scanning method to identify all motor nerve branches (typically 2–3) entering the proximal third of the rectus femoris muscle. Each branch is blocked using an in-plane needle approach with 1–2 mL of 2% lidocaine. Results: The technique enables the visualization of hyperechoic nerve branches entering the rectus femoris muscle from medial to lateral, sometimes accompanied by small vascular branches that are identifiable with a Doppler ultrasound. Optimal ultrasound settings include probes >8 MHz, appropriate focus positioning, and dynamic range < 60 dB. The multi-branch approach produces rapid-onset motor weakness (5–10 min). Conclusions: This comprehensive multi-branch rectus femoris nerve block technique may enhance diagnostic accuracy for spasticity assessment, potentially leading to more informed treatment selection for stiff-knee gait. Full article

The early flowering and less lateral branches in watermelon hold significant agricultural value. The synergistic effects of these traits provide an ideal template for watermelon plant architecture improvement. However, the molecular regulatory networks underlying the development of lateral organs (including branches and flowers) in watermelon remain unclear. In this study, we found ClTFL1 knockout lines significantly promote flowering time and inhibit lateral branching and tendril formation, while also leading to a mild apical flower phenotype. These findings indicate that the function of ClTFL1 in watermelon is more extensive than that of its homologous genes in Arabidopsis, rice, and tomato. Through yeast two-hybrid screening, we identified the interacting proteins of ClTFL1, including members of the 14-3-3 family ClGRF8, ClGRF9, and ClGRF12. Bimolecular fluorescence complementation (BiFC) assays further demonstrated ClTFL1 could directly interact with the ClGRF8, ClGRF9, and ClGRF12 protein. The knockout of ClGRF8 and ClGRF12 leads to reduced lateral branches and early flowering. These phenotypes are highly consistent with those of ClTFL1 knockout mutants. Our findings demonstrate the important role of the ClTFL1-ClGRFs module in regulating lateral organ development and flowering time in watermelon, offering important targets for watermelon plant architectural modification and molecular breeding. Full article

Aberrant internal carotid arteries (ICA) are congenital vascular anomalies that occur from involution of the cervical portion of the ICA, which leads to enlargement of the normally small collateral inferior tympanic and caroticotympanic arteries. The inferior tympanic artery is a branch of the external carotid artery, usually the ascending pharyngeal artery, which extends through the inferior tympanic canaliculus (ITC), a small foramen located along the cochlea promontory. Aberrant ICAs can also be associated with a persistent stapedial artery (PSA), which is an abnormal vessel that arises from the petrous ICA and passes through the obturator foramen of the stapes. An aberrant ICA is a very important anomaly to recognize on imaging. Accurately describing its presence is important to help prevent iatrogenic injury during intervention. It is also important to distinguish an aberrant ICA from a lateralized ICA. The improvement of spatial resolution with photon counting detector (PCD)-CT has been proven to provide higher performance in detection of sub-centimeter vascular lesions compared to conventional energy-integrated detector (EID)-CT. PCD-CT also provides superior visualization of small skull-based foramina such as the inferior tympanic canaliculus, which can aid in more accurately characterizing an aberrant ICA (variant course without ITC involvement). Full article

The arbuscular mycorrhizal fungi (AMF) effect on the plant metabolome is an actual question of plant biology. Its alteration during host plant development and at different phosphorus supplies is of special interest. The aim of this study was to evaluate the effect of Rhizophagus irregularis (Błaszk., Wubet, Renker & Buscot) C. Walker & A. Schüßler inoculation and/or phosphorus treatment on the root metabolome of Medicago lupulina L. subsp. vulgaris Koch at the first true leaf, second leaf, third leaf development stages, the lateral branching initiation, the flowering and the mature fruit stages. The assessment of metabolic profiles was performed using GC-MS. In total, 327 metabolites were annotated: among them 20 carboxylic acids, 26 amino acids, 14 fatty acids and 58 sugars. The efficient AM was characterized by the upregulation of the metabolism of proteins, carbohydrates and lipids, as well as an increase in the content of phosphates. The tricarboxylic acid abundance was generally lower during mycorrhization. Fourteen metabolic markers of the efficient AM symbiosis were identified. The lateral branching initiation stage was shown to have key importance. Long-lasting metabolomic profiling indicated variances in mycorrhization and Pi supply effects at different key stages of host plant development. Full article

Prunus humilis is rich in various minerals, organic acids, proteins, and carbohydrates, but its sour taste limits fresh consumption and industry growth. Methyl jasmonate, a plant growth regulator known to enhance fruit quality, has been studied in other fruits, but research on its effects on P. humilis has not yet been reported. This experiment used the P. humilis cultivar ‘Nongda No. 4’ as the material. During the fruit development stages (the pre-young fruit stage and pre-coloring and enlargement stage), the fruiting branches were sprayed with a 20 mg/L methyl jasmonate solution four times. The results indicate that exogenous methyl jasmonate increases the content of various sugar components in P. humilis fruits throughout their development, with a particularly strong effect in the later stages of fruit development. It effectively reduces the content of malic acid and citric acid in these later stages while significantly enhancing flavor-related attributes such as the sweetness, sugar–acid ratio, and sweetness–acid ratio. Moreover, methyl jasmonate markedly promoted the accumulation of different forms of calcium in the fruit. Specifically, at the fully ripe stage, the total sugar content increased significantly by 18.64% (p < 0.05), the total acid content decreased by 15.95% (p < 0.05), and the total calcium content increased by 55.98% (p < 0.05). Correlation and principal component analyses revealed that sugars, acids, and calcium are closely linked in P. humilis, and exogenous treatment with methyl jasmonate effectively improved the overall quality score of sugars, acids, and calcium in the fruit throughout its development. In conclusion, exogenous methyl jasmonate can effectively improve the sugar–acid quality, flavor, and calcium content of P. humilis fruits. This provides a theoretical foundation for cultivation management, quality enhancement, and the breeding of fresh-eating cultivars. Full article

This study presents a facile approach to fabricate PBAT/PHBV films with superior mechanical and barrier properties by in situ forming ribbon-like lamellae, achieving a PHBV platelet-reinforced PBAT films. The fabrication involves melt blending of PBAT and PHBV, where styrene–methyl methacrylate–glycidyl methacrylate copolymer as a multifunctional reactive compatibilizer (RC) regulates PHBV domain size by forming a branched/cross-linked PBAT-B-PHBV structure. The introduction of a compatibilizer into the PBAT/PHBV system can reduce domain size and improve interfacial adhesion, thereby elevating PBAT’s storage modulus and complex viscosity for optimized blow-molding processability. During blow-molding, biaxial stretching with rapid cooling transforms PHBV sea–island structures into well-aligned ribbon-like lamellae. Notably, when PHBV content is ≤30 wt.%, lamellae form in the PBAT matrix, significantly enhancing both mechanical and barrier properties. The addition of RC reduces the lateral dimensions of PHBV lamellae while increasing PHBV number density. The introduction of 0.2 wt.% RC optimizes lamellar dimensions and density to maximize permeation pathway tortuosity. Ultimately, the lamellae in the PBAT matrix yield remarkable property enhancements: yield strength increased by >600%, elastic modulus by >200%, and water vapor/oxygen transmission rate reduced by ~81% and ~85%, respectively. Full article