Structure Of Appendages Research Articles

A dual-layer nano dressing with enhanced antimicrobial and healing properties via sesame nanoemulgel with efficient levofloxacin delivery for wound management

Creating suitable wound dressings is considered a promising approach for treating severe skin injuries, as they can provide the environment for healing and protection against infection. The optimum wound dressing should possess biocompatibility, high absorbency, antimicrobial activity, breathability, and mechanical strength. So, in this study, we created a two-layer dressing that includes a surface layer composed of xanthan, polyvinyl alcohol, and sesame oil, as well as a nanofibrous sublayer that contains polyvinyl alcohol, collagen, levofloxacin, and sesame oil nanoemulsion (Video 1). This dual structure is designed to offer antimicrobial properties and facilitate wound healing while having suitable physical stability. The films showed desirable morphological features and significantly increased flexibility (less than 1000). These features were respectively proven through scanning electron microscopy and tensile strength. Laboratory investigations were conducted to examine the precise compatibility and anti-inflammatory features. According to the obtained results, the nanosystems showed compatibility with hemolysis below 5 percent and by adding sesame oil to the films, their anti-inflammatory properties (88 ± 0.19 %) and blood compatibility (1.3507 ± 0.20) increased. In-vivo studies using the rat skin defect model showed that the dressings significantly accelerate the closure of skin wounds and enhance the reconstruction of skin appendage structures. The therapeutic effect resulted from reducing inflammatory factors, and the film's antimicrobial properties effectively prevent the growth of harmful microorganisms. In conclusion, the study suggests that the new nano-biocomposite films suit wound management.

Appendage-resident epithelial cells expedite wound healing response in adult zebrafish

Adult zebrafish are able to heal large-sized cutaneous wounds in hours with little to no scarring. This rapid re-epithelialization is crucial for preventing infection and jumpstarting the subsequent regeneration of damaged tissues. Despite significant progress in understanding this process, it remains unclear how vast numbers of epithelial cells are orchestrated on an organismic scale to ensure the timely closure of millimeter-sized wounds. Here, we report an unexpected role of adult zebrafish appendages (fins) in accelerating the re-epithelialization process. Through whole-body monitoring of single-cell dynamics in live animals, we found that fin-resident epithelial cells (FECs) are highly mobile and migrate to cover wounds in nearby body regions. Upon injury, FECs readily undergo organ-level mobilization, allowing for coverage of body surfaces of up to 4.78mm2 in less than 8 h. Intriguingly, long-term fate-tracking experiments revealed that the migratory FECs are not short-lived at the wound site; instead, the cells can persist on the body surface for more than a year. Our experiments on "fin-less" and "fin-gaining" individuals demonstrated that the fin structures are not only capable of promoting rapid re-epithelialization but are also necessary for the process. We further found that fin-enriched extracellular matrix laminins promote the active migration of FECs by facilitating lamellipodia formation. These findings lead us to conclude that appendage structures in regenerative vertebrates, such as fins, may possess a previously unrecognized function beyond serving as locomotor organs. The appendages may also act as a massive reservoir of healing cells, which speed up wound closure and tissue repair.

Skin appendage abnormalities in hypothyroidism: understanding and management

Introduction and purpose Thyroid ailments are frequently encountered in medical practice, often intertwined with a variety of conditions that may or may not share common underlying factors. Among the organs profoundly influenced by these disorders is the skin, which manifests a diverse array of clinical presentations. However, the exact changes in the structure of skin appendages have not been well studied. Changes in hair structure or nail findings may be helpful in early diagnosis of thyroid disorders and therefore are important for dermatologist education. Hair loss can be a very uncomfortable and embarrassing ailment. Many diseases, nutritional deficiencies, stress and other factors can affect the hair condition and even induce its falling out. This review seeks to explore the numerous skin disorders arising directly or indirectly from thyroid irregularities, offering an updated understanding of the interplay between thyroid function and skin health. State of Knowledge It is well-established in scientific literature that thyroid gland disorders, particularly hypothyroidism, induce metabolic deceleration, influencing the inadequate nourishment of skin appendages, resulting in skin dryness and fragility. Patients commonly report pallor, cold intolerance, and deteriorating hair and nail quality. Conclusion We noticed strong correlation between hair loss and the autoimmune process during the dysfunction of thyroid. Euthyroidism plays an important role in hair cycle and any changes can disturb its proper development. In Hashimoto disease elevated levels of antibodies negatively influence hair cycle by excessively inducing telogen phase. Moreover, the blood vessels of the skin constrict disrupting the blood flow which affects hair follicles.

Clinico-pathological Study of Skin Appendageal Tumours: An Experience at a Tertiary Care Hospital.

Skin appendageal tumours (SATs) are uncommon tumours that differentiate towards one or more appendageal structures. Benign SATs are relatively common, while malignant tumours are rare. These are locally aggressive tumours, with malignant cases having a poor clinical outcome. Histopathology remains the gold standard in the diagnosis of SATs. Correct diagnosis of SATs is important for the appropriate management of patients. In the present study, we analyzed the epidemiological profile and histopathological features of benign and malignant SATs. A total of 30,200 biopsies from skin lesions were received from January 2011 to September 2021 in the department of pathology. Out of all the biopsies, 293 cases were diagnosed as SATs. The age ranged from 3 to 82years, with a male-to-female ratio of 1.29:1. Tumours of sweat gland differentiation, i.e., both apocrine and eccrine, constituted the largest group with 43% (126/293) cases, followed by tumours showing follicular differentiation with 28.32% (83/293) cases, and tumours with sebaceous differentiation in 27.30% (80/293) cases. To conclude, skin appendageal tumours are an uncommon group of tumours. Since, these tumours have morphological overlap and are rare, the diagnosis is often a challenge for the pathologist.

O12 Macrophages enhance angiogenesis in an induced pluripotent stem cell-derived skin organoid model

Abstract Introduction and aims Hair-bearing skin organoids (SkOs) are a complex three-dimensional (3D) model that faithfully recapitulates human skin as a multicellular organ with appendage structures. The development of such models provides unique potential for investigating human skin development and translational dermatology. Although this model answers many demands of an investigative tool, one obvious limitation is the absence of immune cells in SkOs. Our aim is to generate coculture systems of SkOs with macrophages to investigate how macrophages influence skin development. Methods Our group, and others, generated single-cell (sc)RNA-Seq and spatial transcriptomic datasets to thoroughly characterize human skin cell populations across the human lifespan. We used these datasets to compare the dynamic tempo of induced pluripotent stem cell (iPSC)-derived SkO (n = 84) differentiation with human prenatal (n = 15) and adult skin. For functional assays, we generated 2D angiogenesis coculture assays with macrophages and endothelial cells (n = 3) and 3D coculture of SkOs with macrophages (n = 3). Macrophages, endothelial cells and SkOs were all derived from the same iPSC line following established protocols. SkO vasculature was analysed after immunowholemount staining of CD31+ endothelial cells. Results Analysis of scRNA-Seq data highlighted a paucity in endothelial cell heterogeneity in SkOs compared with prenatal skin. We hypothesized that this could be explained by the absence of immune cells, as spatial transcriptomics microenvironment analysis of prenatal skin demonstrated that endothelial cells collocate with macrophages. With this in mind, we generated functional assays to investigate interactions of macrophages and endothelial cells in skin development. The 2D and 3D assays revealed that presence of macrophages significantly increased endothelial cell sprouting and network formation. Conclusions Our findings suggest a vital role of macrophages in skin morphogenesis, specifically in relation to the guidance of tip cells during angiogenesis. In addition, we present the SkO as an excellent complex model for investigating skin development, cell–cell interactions, and disease modelling for translational research in regenerative medicine and beyond.

Macromia kannharaiensis, a new species of dragonfly (Insecta: Odonata: Macromiidae) from Maharashtra, India

We describe a new species of dragonfly Macromia kannharaiensis sp. nov., based on a male and a female specimens collected from Dodamarg taluka, Sindhudurg district, Maharashtra. The new species belongs to the calliope–group (species group initially discussed by Laidlaw 1922), and it can be distinguished by its congeners on the bases of specific colour pattern on postclypeus, markings on S2 and S8, shape and structure of caudal appendages and accessory genitalia.

Moving lab-grown tissues into the clinic: organ-on-a-chip and bioengineered skin systems

For patients with end stage organ failure, organ transplant is frequently the only curative option available. However, organs available for transplant are in critically short supply around the world, which has led to lengthy wait times and increased mortality. Increased global life expectancy, coupled with raised age thresholds for recipients, has heightened demand and further compounded the need for alternative strategies. Bioengineering substitutes including organ-on-a-chip and 3D bioprinting technologies have made considerable strides toward whole organ generation. Skin is the organ where the most advances have been made thus far, due to the relatively less complex spatial architecture and industry interest in the development of sophisticated models for pharmaceutical and cosmetics testing. Here, we discuss the challenges of recapitulating the complexity of native skin, including a stratified structure, vascularization, and inclusion of skin appendages, such as hair follicles and sweat glands. We discuss current technological and biological progress in the field of tissue and organ bioengineering as well as highlight future challenges to generate de novo tissue for skin grafting.

Association of Left Atrial Appendage Morphology and Function With Stroke and Transient Ischemic Attack in Atrial Fibrillation Patients

We aimed to correlate left atrial appendage (LAA) structure and function with the history of stroke/transient ischemic attack (TIA) in patients with atrial fibrillation (AF). We analyzed data of 649 patients with AF who were scheduled for catheter ablation. Patients underwent cardiac CT and transesophageal echocardiography prior to ablation. LAA morphologies depicted by cardiac CT were categorized into four groups: cauliflower, chicken wing, swan and windsock shapes. Mean age was 61.3±10.5 years, 33.9% were female. Prevalence of stroke/TIA was 7.1%. After adjustment for the main risk factors, LAA flow velocity ≤35.3 cm/sec (OR=2.18; 95%CI=1.09-4.61; p=0.033) and swan LAA shape (OR=2.69; 95%CI=0.96-6.86; p=0.047) independently associated with higher risk of stroke/TIA, while windsock LAA morphology proved to be protective (OR=0.32; 95%CI=0.12-0.77; p=0.017) as compared to cauliflower LAA shape. When comparing the differences between LAA morphology groups, we measured significantly smaller LAA orifice area (389.3±137.7 mm2 in windsock vs 428.3±158.9 ml in cauliflower, p=0.021) and LAA volume (7.4±3.0 mm2 in windsock vs 8.5±4.8 mm2 in cauliflower, p=0.012) in patients with windsock LAA morphology, while LAA flow velocity did not differ significantly. Reduced LAA function and swan LAA morphology were independently associated with higher prevalence of stroke/TIA, while windsock LAA shape proved to be protective. When comparing the differences between the various LAA morphology types, significantly lower LAA volume and LAA orifice area were measured in windsock LAA shape as compared to cauliflower LAA shape.

Distinct stem-like cell populations facilitate functional regeneration of the Cladonema medusa tentacle.

Blastema formation is a crucial process that provides a cellular source for regenerating tissues and organs. While bilaterians have diversified blastema formation methods, its mechanisms in non-bilaterians remain poorly understood. Cnidarian jellyfish, or medusae, represent early-branching metazoans that exhibit complex morphology and possess defined appendage structures highlighted by tentacles with stinging cells (nematocytes). Here, we investigate the mechanisms of tentacle regeneration, using the hydrozoan jellyfish Cladonema pacificum. We show that proliferative cells accumulate at the tentacle amputation site and form a blastema composed of cells with stem cell morphology. Nucleoside pulse-chase experiments indicate that most repair-specific proliferative cells (RSPCs) in the blastema are distinct from resident stem cells. We further demonstrate that resident stem cells control nematogenesis and tentacle elongation during both homeostasis and regeneration as homeostatic stem cells, while RSPCs preferentially differentiate into epithelial cells in the newly formed tentacle, analogous to lineage-restricted stem/progenitor cells observed in salamander limbs. Taken together, our findings propose a regeneration mechanism that utilizes both resident homeostatic stem cells (RHSCs) and RSPCs, which in conjunction efficiently enable functional appendage regeneration, and provide novel insight into the diversification of blastema formation across animal evolution.

150th anniversary of Alberto Santos-Dumont’s birth, the father of aviation: the damselfly Cyanallagma demoiselle sp. nov. from the Brazilian Atlantic Forest (Odonata: Coenagrionidae)

Cyanallagma demoiselle sp. nov. (holotype male deposited in DZUP: Brazil, São Paulo State, Cananéia, Ilha do Cardoso State Park), a new small greenish blue and black damselfly, is described, illustrated, and diagnosed based on males and females from the southeastern Atlantic Forest. This new coenagrionid is named after one of the most celebrated projects, the Demoiselle 20 or libellule aircraft, designed by the Brazilian inventor and aviation pioneer Alberto Santos-Dumont (1873–1932). This is the third new odonate species discovered in the same restinga-like formation at São Paulo, and like many other odonates from this assemblage, C. demoiselle sp. nov., appears to be a typical inhabitant of this type of environment. Due to its sharing many characteristics with other Cyan­allagma, the new species can be considered a chimera. Its body coloration and genital ligula are similar to those of C. trimaculatum, whereas its caudal appendages closely resemble those of C. nigrinuchale. Despite of recent advances in taxonomic knowledge about Cyan­allagma, this study highlights the need for better understanding the morphological correspondences or homologies among the structures of caudal appendages.

Taxonomic and life cycle reappraisals of the marine basidiomycete Nia vibrissa complex, with descriptions of three new Nia species

ABSTRACT The marine basidiomycete Nia vibrissa has been regarded as a species complex, possibly including several species, because morphological variations in fruitbody, spore, and spore appendage have been observed in materials from worldwide collections. Using more than 50 monosporic isolates of N. vibrissa–like fungi mainly obtained from Japanese beach coasts, we investigated their molecular phylogeny, morphological characteristics, mating compatibility, nuclear behavior during spore formation, and life cycles. Molecular phylogenetic analyses separated the examined strains into seven clades. Each clade of fungi exhibited distinctive characteristics in fruitbodies and spores produced by culturing monokaryotic strains and mated dikaryotic strains; these characteristics included the color of fruitbodies, apical structure of peridial hair hyphae, spore shape, and apical structure of spore appendages. Mating tests of monokaryotic strains demonstrated mating compatibility between strains within a clade and incompatibility among clades. Therefore, each clade of fungi was phylogenetically, morphologically, and biologically recognized as a different Nia species. Observation of the type specimen of N. vibrissa revealed a tiny T-shaped apical structure of spore appendages—not mentioned in the original description—that is unique to the species. This finding, together with the original description, suggests that our studied strains include N. aff. vibrissa, whose morphology is mostly identical to N. vibrissa sensu stricto, and three new species. Thus, we describe three new Nia species and propose emendation of the descriptions of the genus Nia. Culture-based studies have demonstrated that Nia species have both sexual and asexual morphs that produce morphologically similar fruitbodies (basidiomata and conidiomata) and spores (basidiospores and conidia). Because it has both morphs forming appendaged waterborne basidiospores and conidia, Nia must be the most well-adapted marine basidiomycete, ensuring the continuation of new generations by two morphs, while distributing in and inhabiting numerous marine environments.

Deep learning based histological classification of adnex tumors

BackgroundCutaneous adnexal tumors are a diverse group of tumors arising from structures of the hair appendages. Although often benign, malignant entities occur which can metastasize and lead to patients´ death. Correct diagnosis is critical to ensure optimal treatment and best possible patient outcome. Artificial intelligence (AI) in the form of deep neural networks has recently shown enormous potential in the field of medicine including pathology, where we and others have found common cutaneous tumors can be detected with high sensitivity and specificity. To become a widely applied tool, AI approaches will also need to reliably detect and distinguish less common tumor entities including the diverse group of cutaneous adnexal tumors. MethodsTo assess the potential of AI to recognize cutaneous adnexal tumors, we selected a diverse set of these entities from five German centers. The algorithm was trained with samples from four centers and then tested on slides from the fifth center. ResultsThe neural network was able to differentiate 14 different cutaneous adnexal tumors and distinguish them from more common cutaneous tumors (i.e. basal cell carcinoma and seborrheic keratosis). The total accuracy on the test set for classifying 248 samples into these 16 diagnoses was 89.92 %. Our findings support AI can distinguish rare tumors, for morphologically distinct entities even with very limited case numbers (< 50) for training. ConclusionThis study further underlines the enormous potential of AI in pathology which could become a standard tool to aid pathologists in routine diagnostics in the foreseeable future. The final diagnostic responsibility will remain with the pathologist.

An ingenious composite microstructure of mantis shrimp appendage for improving impact resistance

Mantis shrimp appendage, as an important weapon for hunting, have remarkable impact resistance due to their unique microstructure. In this study, the appendages were subjected to falling ball impact tests and their fracture surfaces were observed by scanning electron microscopy. It was observed that the outer layer was prone to brittle fracture, while the inner layer was more flexible and turned the brittle fracture into a ductile fracture. Our study supported the idea that the unique microstructures in the appendages act as barriers against crack growth and therefore play a leading role in the toughening of the entire appendage structure. Based on the bionic inspiration of the appendage microstructure, a bionic composite structure was designed, which consists of a rigid outer layer and a flexible inner layer. The fibers in the flexible layer show a longitudinal and sinusoidal arrangement to provide shielding to the crack tip when the fracture occurs. The toughening mechanism of the microstructure was further corroborated through finite element simulations, which demonstrated that the longitudinal arrangement of fibers played a pivotal role in spreading stress concentration and thereby delaying the fracture process. The sinusoidal arrangement of fibers was also found to be instrumental in not only bridging the rigid and flexible layers, but also in directing the deviation of the crack path. This work was enlightening for the structural design of impact-resistant composites.

CFD-based Numerical Analysis of Amphibious Vehicle Hydrodynamics during Turning Motion

Amphibious vehicle has blunt bow and multi appendage structure, and its flow field characteristics are very complicated during maneuvering. In this paper, a simplified model of amphibious vehicle with propulsion device is established, and the thrust volume force model is introduced to consider the pumping and water jet propulsion of the water effects jet propulsion device. The technique of overlapping grid is used to deal with the six-degree-of-freedom large-scale hull motion problem, and study the turning motion of amphibious vehicle under different rudder angles. The results of numerical simulation show that the amphibious vehicle will enter a stable turning state when turning on the water surface, but the heel angle is large, the draft depth and the speed drop are significant. The state of water baffle has a significant influence on vehicle trim and roll motion. Larger vehicle pitching motion amplitude will increase the risk of overturning.

Description of Protosticta armageddonia sp. nov. (Odonata: Zygoptera: Platystictidae) from the Western Ghats of India

A new species of Protosticta Selys, 1885 is described based on specimens collected from Kerala, northeast of Thiruvananthapuram, in the southern parts of the southern Western Ghats of India. Protosticta armageddonia sp. nov. is compared with all other known Protosticta species of the Western Ghats to provide comprehensive differential diagnosis. The new species is distinguished from its congeners by a combination of characters, including a marking on the ventral side of thorax, structure and colour of the prothorax, markings on the 8th abdominal segment, and the structure of caudal appendages and genital ligula. Furthermore, we provide preliminary information on the ecology and natural history of the new species.

Observations on the ultrastructure of the oral appendages of Glenea cantor Fabricius (Coleoptera: Lamiinae).

Using scanning electron microscopy, we examined the gross and ultrastructure morphology of the mandibles, labial palpi, and mandibular palpi of adult male and female Glenea cantor beetles. The morphology of these parts, both in their gross and ultrastructure, varied significantly between males and females. The lengths of the mandible, labial palpi, and mandibular palpi were clearly noticeably longer in females than in men, which is mostly related to the oviposition mechanism. In terms of the ultrastructural morphology of the mandibles, labial palpi, and mandibular palpi, seven types of sensilla were found on these parts: sensilla twig basiconica (STB I, II, III, and IV), sensilla chaetica (Scheme IV and V), Böhm's bristles (Bb), sensilla placodea (SP), sensilla trichodea (ST II), sensilla plate (SP), sensilla coeloconica (SC), and sensilla campaniformia (SCa). Females have significantly more ST I and Scheme III on their mandibles than males. The mechanical sensors SCh and Bb, olfactory sensor ST II, taste sensor STB IV, and carbon dioxide sensor and temperature and humidity sensors SC, SP, and SCa were much more developed on the labial and maxillary palpi of females compared to those of males, which further clarified the significance of the oral appendages in oviposition behavior. These findings will advance information-based technique design and the creation of information-based pest control strategies by assisting in our understanding of the host preference and oviposition behavior of adult G. cantor. RESEARCH HIGHLIGHTS: The external morphology and distribution of the oral appendages of Glenea cantor between sexes has been researched through scanning electron microscopy (SEM) for the first time. Several significant differences between males and females have been found by analyzing the oral appendages of G. cantor with SEM. The differences in the structure of oral appendages of G. cantor between sexes reflect functional differences in reproductive behaviors.

Taxonomic review of Kaloplocamus from the Yellow Sea, China with the description of a new species (Nudibranchia, Doridina, Polyceridae).

Species of Kaloplocamus Bergh, 1880 are enigmatic Nudibranchia sea slugs, and only two valid species are reported in the northwestern Pacific. Kaloplocamusjaponicus (Bergh, 1880) was initially described based on alcohol-fixed specimens. In the latest revision of Kaloplocamus, it was synonymized with Kaloplocamusramosus (Cantraine, 1835). Recently, several nudibranchs were collected from Tianheng, Shandong Province, China, and one of them is identified as an undescribed species described here as Kaloplocamusalbopunctatussp. nov. based on integrated approaches incorporating morphological observations, internal anatomy, and phylogenetic analyses of two mitochondrial (COI, 16S rRNA) genes. The other species is identified as K.japonicus Bergh, 1880 based on the anatomy of the reproductive system. The new species K.albopunctatussp. nov. is similar to K.ramosus in having a bright orange-red color pattern but differs significantly in the structure of appendages and reproductive system. Kaloplocamusjaponicus can be easily distinguished from other Kaloplocamus species by its translucent, white-pink coloration and unique features of the female reproductive organ. Both species are supported as distinct species in all molecular analyses. The phylogenetic analyses propose a new estimate of the relationship between Kaloplocamus and Plocamopherus, and the evolution of bioluminescence within Triophinae is discussed. Our results also suggest cryptic biodiversity within the K.ramosus species complex.

Morphological description and molecular characterization of Ancyracanthus electrophori n. sp. (Gnathostomatoidea: Gnathostomatidae): a new nematode parasitic in the electric eel Electrophorus varii (Gymnotiformes: Gymnotidae), from the Brazilian Amazon.

A new species of Ancyracanthus, parasite of the electric eel Electrophorus varii, in the Brazilian Amazon, is described based on morphological and molecular characterization. Ancyracanthus electrophori n. sp. differs from the two congeners namely, Ancyracanthus pinnatifidus and Ancyracanthus schubarti, based on the structure of cephalic appendages, number and arrangement of caudal papillae in males, vulva very close to anus in females, eggs with smoothly mamillated shell, host taxon and geographical origin. Moreover, the new species is the first in the genus to be described with thorny cuticular rings and to be observed with the use of scanning electron microscopy (SEM). The morphology of A. pinnatifidus and A. schubarti is still poorly-known and should be revised in details; however, the separation between them and the new species was clear. Genetic characterization based on 28S rDNA and cytochrome c oxidase subunit I (cox1) mtDNA partial sequences, performed for the first time in Acyracanthus, along with phylogenetic reconstructions using both genetic markers, placed Ancyracanthus electrophori n. sp. in a suggestive basal position within Gnathostomatidae. Phylogenetic reconstructions using cox1 sequences also suggested lack of monophyly in the genera Gnathostoma and Spiroxys and, consequently, in the subfamilies Gnathostominae and Spiroxyinae. However, such results are preliminary. With the first genetic characterization and observations using SEM in Ancyracanthus, resulting in the discovery of a new species and in the expansion of the geographical occurrence of the genus to Amazonian fish, an important step towards a better understanding of these nematodes has been taken.

EMCAPT study: the effect of MitraClip treatment on the mitral annulus and left atrial appendage evaluation by transoesophageal echocardiography.

Data on the change in mitral valve annulus diameter (MAD), and left atrial appendage (LAA) structure and function after transcatheter edge-to-edge repair (TEER) of the mitral valve in patients with secondary mitral regurgitation (MR) are lacking. To evaluate the change in these parameters just after the clip insertion and its relationship with prognosis in the long term. A total of 50 patients (age: 71.5 ±11.3 years, 70% male) with moderate-to-severe or severe MR were included in the study. Transthoracic (TTE) and transoesophageal echocardiography (TEE) were performed before and after the procedure. Prognostic data were recorded with post-procedure telephone calls and follow-up visits. TEE performed during the procedure showed that LAA contraction and filling velocity significantly increased (p < 0.001 for all). Systolic pulmonary artery pressure (SPAP), MAD, and LAA landing zone dimension significantly decreased (p < 0.001 for all). There was only a significant correlation between the MAD before clip placement and the MAD change after clip placement (r = 0.6, p < 0.001). During a mean follow-up period of 10.5 ±8.9 months, no significant correlation was found between MAD change, LAA contraction and filling velocity change, and LAA landing zone dimension change and rehospitalization, stroke, mortality, and composite outcome. The contraction and filling velocity of LAA, SPAP, MAD, and LAA landing zone dimension changed significantly immediately after the MitraClip procedure. Although these parameters are not related to composite outcome in our study, MAD, LAA diameter, and velocity need to be compared between successful and unsuccessful procedures to predict their clinical relevance.

Fiber arrangement endow compression resistance of the mantis shrimp hammer-like appendage

For engineering materials, it is important to search for strategies to enhance certain combinations of mechanical properties, because many performances, such as strength and toughness, are mutually exclusive. Effective strategies have evolved in the biological tissues of many plants and animals to construct composite materials with unique combinations of mechanical properties. One impressive example is found in the hammer-like appendages of mantis shrimp, which are exceptionally resistant to crushing because they must withstand the reaction forces created when attacking prey. In this paper, quasi-static compression tests, advanced microscopic observation, and spectroscopic analysis were employed to identify a series of characteristic changes, including changes in mineral composition and arrangement of chitin fibers, and the resulting toughening mechanisms are also examined. The combination of experiments and finite element analysis revealed that by combining different fiber arrangements and components in adjacent macroscopic layers, longitudinal stress could be shifted to the lateral direction, hence efficiently enhancing longitudinal compression resistance while avoiding catastrophic failure. Overall, these findings further the understanding of the fiber structure and toughening mechanism of appendages, which may serve as a foundation for the development of tough bioinspired composites.