The puncture mechanics: an example from the bed bug Cimex lectularius showing traumatic insemination using the paramere.

Cimicidae are well-known for traumatic insemination, and males pierce females with their parameres and transfer sperm through them. The shape of parameres is relatively stable in the family, but in some genera, the paramere is elongated, appearing less resistant against lateral deflection. To understand the mechanical limitations of the paramere, we studied its penetration mechanics of the common bed bug, Cimex lectularius. We examined the post-abdominal morphology, paramere geometry and material properties and conducted breaking stress experiments on the paramere under wet and dry conditions. Mechanical property gradients are present with the paramere tip as the stiffest region and the base as the most flexible one. These mechanical properties relate to the presence of Ca, Zn and Si. The basal wing-shaped structure is flexible, enabling it to interlock with the anal region during mating. The paramere is slightly twisted; the tip region is circular in cross-section, and the geometry of the rest is rather complex. In the mechanical tests, wet parameres mainly buckled, while dried parameres broke off. The level of structural failures depended on directions from which the compression forces were applied. Structural, material and mechanical strengthening mechanisms preventing the paramere from mechanical failure are discussed.

A new species of Zoraptera, Zorotypuskomatsui sp. nov. from Cameroon and a redescription of Zorotypusvinsoni Paulian, 1951 (Polyneoptera, Zoraptera).

A new species of the order Zoraptera, Zorotypuskomatsui Matsumura, Maruyama, Ntonifor & Beutel, sp. nov., is described from Cameroon. The female and male morphology of another species, Z.vinsoni, is re-described, and its new distribution in Madagascar is recorded. A particular focus is on the male postabdominal morphology. This is apparently a crucial body region in the very small order with an extreme variation of the genital apparatus but otherwise a very uniform morphology. The male of the newly described species shares rudimentary male genitalia and well-developed postabdominal projections with the distantly related Spermozorosimpolitus, apparently a result of parallel evolution. Whether males of Z.komatsui also perform external sperm transfer like S.impolitus remains to be shown. The collecting of the material used for this study suggests that the present knowledge of zorapteran species diversity of the Afrotropical region is very fragmentary.

Antiviral Effect of Candies Containing Persimmon-Derived Tannin against SARS-CoV-2 Delta Strain.

Inactivation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the mouth has the potential to reduce the spread of coronavirus disease 2019 (COVID-19), due to the virus being readily transmitted by dispersed saliva. Persimmon-derived tannin has strong antioxidant and antimicrobial activity owing to its strong adhesion to proteins, and it also exhibited antiviral effects against non-variant and Alpha-variant SARS-CoV-2 in our previous study. In this study, we first demonstrated the antiviral effects of persimmon-derived tannin against the Delta variant of SARS-CoV-2 in vitro via the plaque assay method. We then examined the effects of candy containing persimmon-derived tannin. Remarkably, the saliva samples provided by healthy volunteers while they were eating tannin-containing candy showed that the virus titers of the SARS-CoV-2 Delta variant were suppressed. In addition, we found that the SARS-CoV-2 viral load in saliva from patients with COVID-19 collected immediately after they had eaten the tannin-containing candy was below the level of detection via PCR for SARS-CoV-2. These data suggest that adding persimmon-derived tannin to candy and holding such candy in the mouth is an effective method for inactivating SARS-CoV-2 in saliva, and the application of this approach shows potential for inhibiting the transmission of COVID-19.

The tight attachment achieved by the male discoidal setae is possibly a counter-adaptation to the grease layer on female integument surfaces in green dock beetles.

Green dock beetles Gastrophysa viridula exhibit sexual dimorphism in tarsal attachment setae: females have only pointed, lanceolate and spatula-like setae, while males additionally possess discoidal ones. The sexual dimorphism is probably attributed to the necessity of male discoidal setae to adhere to the smooth back of the female during copulation. We aimed to understand its possible mechanism of attachment with G. viridula. Pull-off forces of both females and males were measured on (i) alive females, (ii) dead and dried females, and (iii) resin replicas of fresh females. The attachment ability tended to increase on dead and replicated female surfaces in both sexes, which indicates that the epicuticular grease layer on the integument of alive intact beetles decreases the attachment. This tendency was prominent in females. The present study clearly showed that in G. viridula discoidal setae enable the males to adhere stronger to female surfaces. The divergent performance found between the sexes differing in their setal composition is probably caused by the stiffness difference between the setae types and by the specific shape of the setal tips. A peculiar reproductive biology in G. viridula is probably attributed to this remarkable divergence of labour in their attachment pads between the sexes.

Dietary Phenolic Compounds: Their Health Benefits and Association with the Gut Microbiota.

Oxidative stress causes various diseases, such as type II diabetes and dyslipidemia, while antioxidants in foods may prevent a number of diseases and delay aging by exerting their effects in vivo. Phenolic compounds are phytochemicals such as flavonoids which consist of flavonols, flavones, flavanonols, flavanones, anthocyanidins, isoflavones, lignans, stilbenoids, curcuminoids, phenolic acids, and tannins. They have phenolic hydroxyl groups in their molecular structures. These compounds are present in most plants, are abundant in nature, and contribute to the bitterness and color of various foods. Dietary phenolic compounds, such as quercetin in onions and sesamin in sesame, exhibit antioxidant activity and help prevent cell aging and diseases. In addition, other kinds of compounds, such as tannins, have larger molecular weights, and many unexplained aspects still exist. The antioxidant activities of phenolic compounds may be beneficial for human health. On the other hand, metabolism by intestinal bacteria changes the structures of these compounds with antioxidant properties, and the resulting metabolites exert their effects in vivo. In recent years, it has become possible to analyze the composition of the intestinal microbiota. The augmentation of the intestinal microbiota by the intake of phenolic compounds has been implicated in disease prevention and symptom recovery. Furthermore, the "brain-gut axis", which is a communication system between the gut microbiome and brain, is attracting increasing attention, and research has revealed that the gut microbiota and dietary phenolic compounds affect brain homeostasis. In this review, we discuss the usefulness of dietary phenolic compounds with antioxidant activities against some diseases, their biotransformation by the gut microbiota, the augmentation of the intestinal microflora, and their effects on the brain-gut axis.

Material gradients in gastropod radulae and their biomechanical significance: a combined approach on the paludomid Lavigeria grandis.

The radula, a chitinous membrane spiked with teeth, is the molluscan autapomorphy for the gathering and processing of food. The teeth, as actual interfaces between the organism and the ingesta, act as load transmitting regions and have to withstand high stresses during foraging - without structural failure or high degrees of wear. Mechanisms contributing to this were studied previously in paludomid gastropods from Lake Tanganyika. For some species, gradients in hardness and Young's modulus along the teeth were detected, enabling the bending and relying of teeth onto the next row, distributing the stresses more equally. The here presented study on one of them - Lavigeria grandis - aims at shedding light on the origin of these functional gradients. The mechanical properties were identified by nanoindentation technique and compared to the elemental composition, determined by elemental dispersive X-ray spectroscopy (EDX, EDS). This was done for the complete radular (mature and immature tooth rows), resulting in overall 236 EDX and 700 nanoindentation measurements. Even though teeth showed regional differences in elemental composition, we could not correlate the mechanical gradients with the elemental proportions. By applying confocal laser scanning microscopy (CLSM), we were finally able to relate the mechanical properties with the degree of tanning. CLSM is a common technique used on arthropod cuticle, but was never applied on radular teeth before. In general, we found that nanoindentation and CLSM techniques complement one another, as for example, CLSM is capable of revealing heterogeneities in material or micro-gradients, which leads to a better understanding of the functionalities of biological materials and structures.

Antioxidant Potential of Non-Extractable Fractions of Dried Persimmon (Diospyros kaki Thunb.) in Streptozotocin-Induced Diabetic Rats.

Oxidative stress causes the progression of diabetes and its complications; thus, maintaining the balance between reactive oxygen species produced by hyperglycemia and the antioxidant defense system is important. We herein examined the antioxidant potential of non-extractable fractions of dried persimmon (NEP) against oxidative stress in diabetic rats. Rats with streptozotocin-induced type 1 diabetes (50 mg/kg body weight) were administered NEP for 9 weeks. Antioxidant enzyme activities and concentration of antioxidants in liver tissues were analyzed with a microplate reader. Extensor digitorum longus (EDL) and soleus muscle fibers were stained with succinate dehydrogenase and muscle fiber sizes were measured. The administration of NEP increased the body weight of diabetes rats. Regarding antioxidant activities, the oxygen radical absorbance capacity and superoxide dismutase activity in liver tissues significantly increased. In addition, increases in glutathione peroxidase activity in liver tissues and reductions in the cross-sectional area of EDL muscle fibers were significantly suppressed. In these results, NEP improved the antioxidant defense system in the liver tissues of diabetic rats, in addition to attenuating of muscle fibers atrophy against oxidative damage induced by hyperglycemia.

Distal leg structures of Zoraptera - did the loss of adhesive devices curb the chance of diversification?

The distal leg structures of Zoraptera are documented and discussed with respect to their functional morphology and evolutionary aspects. We investigated eight species using scanning electron microscopy. We analyzed material compositions of the tarsus in three representative species using confocal laser scanning microscopy. When possible, we included both sexes, wing morphs, and nymphs and compared the structures among them. The distal leg structure is unusually uniform across zorapterans regardless of the sex, morphs, and developmental stages. The observed features combine simplification with innovation. The former is likely partially correlated with cryptic microhabitats and miniaturization. Innovation includes a protibial cleaning organ. This is very likely an autapomorphy of Zoraptera. The tarsi are composed of two tarsomeres covered with setae. The pretarsus distally bears an unguitractor plate and well-sclerotized claws. The tarsomeres appear less-sclerotized than the covering setae. The articulation between the basitarsus and tarsomere 2 is hinge-like, implying that tarsomere 2 moves only mediolaterally. The simplified and specialized tarsal morphology is likely suitable for the typical zorapteran microhabitat, under bark. However, the irreversible complete loss of adhesive devices prevented zorapterans to make use of a broader spectrum of environments and was presumably one reason for the species paucity of the group.

The addition of iguratimod can reduce methotrexate dose in rheumatoid arthritis with clinical remission.

OBJECTIVES: We prospectively evaluated whether the addition of iguratimod (IGU) could sustain clinical remission in rheumatoid arthritis (RA) patients after tapering of methotrexate (MTX). METHODS: The study included 47 patients; 25 patients in the MTX maintenance group, and 22 patients in the IGU addition group who were treated with additional IGU and tapering of MTX dose. Clinical efficacy and safety were evaluated at 12, 24, and 36 weeks. RESULTS: In the IGU addition group, the dose of MTX could be reduced from 8.6 ± 2.4 mg/week at baseline to 4.7 ± 2.2 mg/week at 36 weeks (p < .001). Clinical remission was maintained (disease activity score [DAS]28-ESR 1.48 ± 0.63 at baseline and 1.69 ± 0.76 at 36 weeks, p = .911), and disease activity remained low (clinical disease activity index [CDAI] 2.4 ± 1.5 at baseline and 3.1 ± 3.4 at 36 weeks, p = .825). The US-GLOSS score significantly decreased from 9.2 ± 5.3 at baseline to 6.4 ± 4.3 at 36 weeks (p = .034). In the IGU addition group, two patients discontinued IGU because of stomatitis and three patients relapsed during the follow-up period (flare rate: 15.0%). There was no significant difference in RA disease activity at 36 weeks between the two groups. CONCLUSION: Additional use of IGU can effectively reduce the MTX dose required by patients during clinical remission without inducing a flare.

Successful Repair of a Forme Fruste Bicuspid Aortic Valve by the Raphe Suspension Technique.

A 52-year-old man underwent surgery due to shortness of breath caused by severe aortic regurgitation with right coronary cusp prolapse. Operative findings revealed 3 symmetric cusps with small raphe between the right and noncoronary cusps situated lower than the others, indicating a forme fruste bicuspid aortic valve (BAV). The BAV was successfully repaired by tricuspidization, including raphe suspension, right coronary cusp plication, and double annuloplasty. The postoperative course was uneventful, and echocardiography at 3 months showed mild aortic regurgitation with adequate left ventricular reverse remodeling. Here we present the technical details of the raphe suspension procedure for forme fruste BAV.

Persimmon-derived tannin has antiviral effects and reduces the severity of infection and transmission of SARS-CoV-2 in a Syrian hamster model.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread across the world. Inactivating the virus in saliva and the oral cavity represents a reasonable approach to prevent human-to-human transmission because the virus is easily transmitted through oral routes by dispersed saliva. Persimmon-derived tannin is a condensed type of tannin that has strong antioxidant and antimicrobial activity. In this study, we investigated the antiviral effects of persimmon-derived tannin against SARS-CoV-2 in both in vitro and in vivo models. We found that persimmon-derived tannin suppressed SARS-CoV-2 titers measured by plaque assay in vitro in a dose- and time-dependent manner. We then created a Syrian hamster model by inoculating SARS-CoV-2 into hamsters' mouths. Oral administration of persimmon-derived tannin dissolved in carboxymethyl cellulose before virus inoculation dramatically reduced the severity of pneumonia with lower virus titers compared with a control group inoculated with carboxymethyl cellulose alone. In addition, pre-administration of tannin to uninfected hamsters reduced hamster-to-hamster transmission of SARS-CoV-2 from a cohoused, infected donor cage mate. These data suggest that oral administration of persimmon-derived tannin may help reduce the severity of SARS-CoV-2 infection and transmission of the virus.

Mechanical properties of a female reproductive tract of a beetle and implications for penile penetration.

Coevolution of male and female genitalia is widespread in animals. Nevertheless, few studies have examined the mechanics of genital interactions during mating. We characterized the mechanical properties of the elongated female genitalia, the spermathecal duct, of the small cassidine beetle, Cassida rubiginosa. The data were compared with the mechanical properties of the elongated male genitalia, the flagellum. We analysed the material distributions of the spermathecal duct using a microscopy technique, established a tensile test setup under a light microscope and conducted tensile tests. Diameter and tensile stiffness gradients were present along the spermathecal duct, but its Young's modulus and material distribution were more or less homogeneous. The results confirmed the hypothesis based on numerical simulations that the spermathecal duct is more rigid than the flagellum. In the study species, the penile penetration force is simply applied to the base of the hyper-elongated flagellum and conveyed along the flagellum to its tip. Considering this simple penetration mechanism, the relatively low flexibility of the spermathecal duct, compared to the flagellum, is likely to be essential for effective penetration of the flagellum.

Persimmon-derived tannin ameliorates the pathogenesis of ulcerative colitis in a murine model through inhibition of the inflammatory response and alteration of microbiota.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) induced by dysregulation of the immune response in the intestinal mucosa. Although the underlying mechanisms of UC development are not fully understood, disruption of gut microbiota, "dysbiosis", is thought to lead to the development of IBD. Persimmon (Ebenaceae Diospyros kaki Thunb.)-derived tannin, which is a condensed polymeric tannin consisting of catechin groups, has antioxidant, anti-inflammatory, and antimicrobial activities. In this study, we assessed the effect of persimmon-derived tannin on a murine model of UC established by dextran sulfate sodium-induced colitis in female mice. Dietary supplementation of tannin significantly decreased disease activity and colon inflammation. A hydrolysate of tannin directly suppressed expression of inflammatory genes in macrophages in vitro. In faecal microbiota, the relative abundance of Bacteroides was increased significantly by tannin supplementation. Alpha-diversity indices in colitis-induced mice were significantly higher in the tannin diet group compared with the control diet group. Additionally, expansion of Enterobacteriaceae and Enterococcus, which is associated with disease progression of IBD, was remarkably suppressed in the tannin diet group. These results suggest that persimmon-derived tannin ameliorates colon inflammation in UC through alteration of the microbiota composition and immune response, which may be a promising candidate for IBD therapy.

Penetration mechanics of elongated female and male genitalia of earwigs.

We unveiled the penile penetration mechanics of two earwig species, Echinosoma horridum, whose intromittent organ, termed virga, is extraordinarily long, and E. denticulatum, whose virga is conversely short. We characterised configuration, geometry, material and bending stiffness for both virga and spermatheca. The short virga of E. denticulatum has a material gradient with the stiffer base, whereas the long virga of E. horridum and the spermathecae of both species are homogeneously sclerotised. The long virga of E. horridum has a lower bending stiffness than the spermatheca. The virga of E. denticulatum is overall less flexible than the spermatheca. We compared our results to a previous study on the penetration mechanics of elongated beetle genitalia. Based on the comparison, we hypothesised that the lower stiffness of the male intromittent organ comparing to the corresponding female structure is a universal prerequisite for the penetration mechanics of the elongated intromittent organ in insects.

Simplified disease activity index and clinical disease activity index before and during pregnancy correlate with those at postpartum in patients with rheumatoid arthritis.

OBJECTIVES: We explored rheumatoid arthritis (RA) disease activity before, during, and after pregnancy in patients treated with tight control and investigated the association between disease activity in the postpartum period and those before and during pregnancy. METHODS: We retrospectively reviewed disease activity and medications of 27 patients before pregnancy, at every trimester, and in the postpartum period. RESULTS: Prednisolone was administered to 33% of patients with a median dose of 0 (0-2.5) mg/day and biologic agents was 78% in the third trimester. The median remission rates during all periods were the Disease Activity Score-28-C-reactive Protein assessed with three variables (DAS28-CRP-3) 85%, Simplified Disease Activity Index (SDAI) 55%, and Clinical Disease Activity Index (CDAI) 54%. Although SDAI and CDAI decreased significantly from before pregnancy to the first trimester and increased from the third trimester to the postpartum period, DAS28-CRP-3 did not change during all periods. Although SDAI and CDAI before and during pregnancy were significantly correlated with those in the postpartum period, DAS28-CRP-3 was not. CONCLUSIONS: Tight control before pregnancy suppressed RA disease activity during pregnancy and in the postpartum period. SDAI/CDAI before and during pregnancy were predictive for disease activity in the postpartum period.

Aortic root destruction after aortic valvuloplasty for bicuspid aortic valve.

Ultrasound cardiography showed severe aortic regurgitation (AR) due to bicuspid aortic valve with dilatation of the aortic annulus and sinotubular junction in a 27-year-old man hospitalized with loss of consciousness. He underwent aortic valvuloplasty combined with external suture annuloplasty using an expanded polytetrafluoroethylene (ePTFE) suture. Intraoperative findings revealed thickening and adhesion of the aortic root despite the first surgery. He developed recurrent AR 7 months later and underwent redo surgery. An ePTFE suture was found inside the aorta. Aortic root replacement with a mechanical composite graft was performed, as reconstruction appeared difficult because the aortic annulus was damaged and there were multiple holes on all cusps. Here, we report a rare case of aortic root destruction after external suture annuloplasty.

Material heterogeneity of male genitalia reduces genital damage in a bushcricket during sperm removal behaviour.

Sperm removal behaviour (SRB) is known in many animals, and male genital structures are often involved in the SRB, e.g. rubbing female genitalia vigorously. However, it remains unclear how those male genital structures function properly without severe genital damage during SRB. In the present study, we focused on the bushcricket Metaplastes ornatus and examined the biomechanics of male and female genital structures, involved in their SRB as a model case. During an initial phase of mating, males of this species thrust their subgenital plate with hook-like spurs and many microscopic spines into the female genital chamber. By moving the subgenital plate back-and-forth, males stimulate females, and this stimulation induces the ejection of sperm previously stored in females. We aimed to uncover the mechanics of the interaction between the subgenital plate and genital chamber during SRB. The genital morphology and its material composition were investigated using modern imaging and microscopy techniques. The obtained results showed a pronounced material heterogeneity in the subgenital plate and the genital chamber. The material heterogeneity was completely absent in that of a second bushcricket species, Poecilimon veluchianus, which does not exhibit SRB. Finite element simulations showed that the specific material heterogeneity can redistribute the stress in the subgenital plate of M. ornatus and, thereby, reduces stress concentration during SRB. This may explain why only a few examined males had a broken spur. We suggest that the observed structural features and material heterogeneity in M. ornatus are adaptations to their SRB.

Variation of attachment ability of Nezara viridula (Hemiptera: Pentatomidae) during nymphal development and adult aging.

The present investigation reports data on the attachment ability of the Southern green stink bug Nezara viridula (Hemiptera: Pentatomidae), a relevant pest in the world, along its whole life cycle. Using a centrifugal force tester, we evaluated a) the differences in the attachment ability among the four active nymphal developmental instars (N2-N5 nymphs) and adult to hydrophilic glass, showing an increased attachment ability during ontogenesis, owing to increased pulvilli size and efficiency; b) the possible role of growth and body shape on insect attachment ability on hydrophilic glass during the intermoult period, revealing that N. viridula nymphs attach stronger (higher safety factor) in the first part of the intermoult period; c) the age-specific differences in the attachment ability of adults of both sexes on hydrophilic glass, showing the best performance at an intermediate age, in agreement with a higher proportion of resilin in comparison with younger or older insects; d) the difference in attachment ability on hydrophilic vs. hydrophobic glass along the insect development, revealing a strong effect of surface hydrophobicity on reducing the attachment of N. viridula nymphs and adults. The results on the attachment ability of a hemimetabolous insect along its life cycle are relevant because they 1) shed light on different adaptations of attachment pads in relation to insect size, shape and age; 2) deepen the knowledge on the functional morphological adaptations, thus potentially contributing to the development of suitable control systems for this important pest insect.

Resilin Distribution and Sexual Dimorphism in the Midge Antenna and Their Influence on Frequency Sensitivity.

Small-scale bioacoustic sensors, such as antennae in insects, are often considered, biomechanically, to be not much more than the sum of their basic geometric features. Therefore, little is known about the fine structure and material properties of these sensors-even less so about the degree to which the well-known sexual dimorphism of the insect antenna structure affects those properties. By using confocal laser scanning microscopy (CLSM), we determined material composition patterns and estimated distribution of stiffer and softer materials in the antennae of males and females of the non-biting midge Chironomus riparius. Using finite element modelling (FEM), we also have evidence that the differences in composition of these antennae can influence their mechanical responses. This study points to the possibility that modulating the elastic and viscoelastic properties along the length of the antennae can affect resonant characteristics beyond those expected of simple mass-on-a-spring systems-in this case, a simple banded structure can change the antennal frequency sensitivity. This constitutes a simple principle that, now demonstrated in another Dipteran group, could be widespread in insects to improve various passive and active sensory performances.

Distal leg structures of the Aculeata (Hymenoptera): A comparative evolutionary study of Sceliphron (Sphecidae) and Formica (Formicidae).

The distal parts of the legs of Sceliphron caementarium (Sphecidae) and Formica rufa (Formicidae) are documented and discussed with respect to phylogenetic and functional aspects. The prolegs of Hymenoptera offer an array of evolutionary novelties, mainly linked with two functional syndromes, walking efficiently on different substrates and cleaning the body surface. The protibial-probasitarsomeral cleaning device is almost always well-developed. A complex evolutionary innovation is a triple set of tarsal and pretarsal attachment devices, including tarsal plantulae, probasitarsomeral spatulate setae, and an arolium with an internal spring-like arcus, a dorsal manubrium, and a ventral planta. The probasitarsal adhesive sole and a complex arolium are almost always preserved, whereas the plantulae are often missing. Sceliphron has retained most hymenopteran ground plan features of the legs, and also Formica, even though the adhesive apparatus of Formicidae shows some modifications, likely linked to ground-oriented habits of most ants. Plantulae are always absent in extant ants, and the arolium is often reduced in size, and sometimes vestigial. The arolium contains resilin in both examined species. Additionally, resilin enriched regions are also present in the antenna cleaners of both species, although they differ in which of the involved structures is more flexible, the calcar in Sceliphron and the basitarsal comb in Formica. Functionally, the hymenopteran distal leg combines (a) interlocking mechanisms (claws, spine-like setae) and (b) adhesion mechanisms (plantulae, arolium). On rough substrate, claws and spine-like setae interlock with asperities and secure a firm grip, whereas the unfolding arolium generates adhesive contact on smooth surfaces. Differences of the folded arolium of Sceliphron and Formica probably correlate with differences in the mechanism of folding/unfolding.