Hydrolyzable tannins are incorporated into the endocarp during sclerification of the water caltrop Trapa natans.

The water caltrop (Trapa natans) develops unique woody fruits with unusually large seeds among aquatic plants. During fruit development, the inner fruit wall (endocarp) sclerifies and forms a protective layer for the seed. Endocarp sclerification also occurs in many land plants with large seeds; however, in T. natans, the processes of fruit formation, endocarp hardening, and seed storage take place entirely underwater. To identify potential chemical and structural adaptations for the aquatic environment, we investigated the cell-wall composition in the endocarp at a young developmental stage, as well as at fruit maturity. Our work shows that hydrolyzable tannins-specifically gallotannins-flood the endocarp tissue during secondary wall formation and are integrated into cell walls along with lignin during maturation. Within the secondary walls of mature tissue, we identified unusually strong spectroscopic features of ester linkages, suggesting that the gallotannins and their derivatives are cross-linked to other wall components via ester bonds, leading to unique cell-wall properties. The synthesis of large amounts of water-soluble, defensive aromatic metabolites during secondary wall formation might be a fast way to defend seeds within the insufficiently lignified endocarp of T. natans.

Advanced materials design based on waste wood and bark.

Trees belong to the largest living organisms on Earth and plants in general are one of our main renewable resources. Wood as a material has been used since the beginning of humankind. Today, forestry still provides raw materials for a variety of applications, for example in the building industry, in paper manufacturing and for various wood products. However, many parts of the tree, such as reaction wood, branches and bark are often discarded as forestry residues and waste wood, used as additives in composite materials or burned for energy production. More advanced uses of bark include the extraction of chemical substances for glues, food additives or healthcare, as well as the transformation to advanced carbon materials. Here, we argue that a proper understanding of the internal fibrous structure and the resulting mechanical behaviour of these forest residues allows for the design of materials with greatly varying properties and applications. We show that simple and cheap treatments can give tree bark a leather-like appearance that can be used for the construction of shelters and even the fabrication of woven textiles. This article is part of the theme issue 'Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 1)'.

An AP2/ERF transcription factor ERF139 coordinates xylem cell expansion and secondary cell wall deposition.

Differentiation of xylem elements involves cell expansion, secondary cell wall (SCW) deposition and programmed cell death. Transitions between these phases require strict spatiotemporal control. The function of Populus ERF139 (Potri.013G101100) in xylem differentiation was characterized in transgenic overexpression and dominant repressor lines of ERF139 in hybrid aspen (Populus tremula × tremuloides). Xylem properties, SCW chemistry and downstream targets were analyzed in both types of transgenic trees using microscopy techniques, Fourier transform-infrared spectroscopy, pyrolysis-GC/MS, wet chemistry methods and RNA sequencing. Opposite phenotypes were observed in the secondary xylem vessel sizes and SCW chemistry in the two different types of transgenic trees, supporting the function of ERF139 in suppressing the radial expansion of vessel elements and stimulating accumulation of guaiacyl-type lignin and possibly also xylan. Comparative transcriptomics identified genes related to SCW biosynthesis (LAC5, LBD15, MYB86) and salt and drought stress-responsive genes (ANAC002, ABA1) as potential direct targets of ERF139. The phenotypes of the transgenic trees and the stem expression profiles of ERF139 potential target genes support the role of ERF139 as a transcriptional regulator of xylem cell expansion and SCW formation, possibly in response to osmotic changes of the cells.

Unraveling the Rapid Assembly Process of Stiff Cellulosic Fibers from Mistletoe Berries.

The mucilaginous viscin tissue within mistletoe berries possesses an extraordinary ability to be rapidly processed under ambient conditions into stiff cellulosic fibers (>14 GPa) through simple mechanical drawing. This rapid and extreme transformation process is hydration-dependent and involves an astonishing >200-fold increase in length, providing a relevant role model for efforts to produce advanced composites from cellulose-based structures such as cellulose nanocrystals or cellulose nanofibrils. Using a combination of in situ polarized light microscopy, synchrotron X-ray scattering, and humidity-controlled mechanical analysis, we examine here the dynamic transition of a viscin cell bundle from hydrogel-like tissues to high-performance fibers. Our findings indicate a massive phase transition in which cellulose microfibrils containing high-aspect-ratio crystalline domains undergo dramatic reorganization, facilitated by a water-responsive noncellulosic matrix. Transition from an aligned, yet flowing state to a stiff fiber is likely triggered by rapid water loss below 45% relative humidity. These findings not only help understanding the adaptive success of mistletoe but may also be relevant for the development of new facile processing methods for next-generation cellulosic composites.

Influence of Genotype and Hyperandrogenism on Sexual Function in Women With Congenital Adrenal Hyperplasia.

BACKGROUND: Depending on CYP21A2 genotype, congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency leads to biochemical alterations (including hyperandrogenism, hypocortisolism, and hypoaldosteronism) and a wide spectrum of phenotypic disease manifestation. The latter include life-threatening salt-wasting crises, prenatal virilization of genitalia in women (classic CAH [C-CAH]) as well as milder forms of the disease exclusively presenting with hirsutism, acne or reduced fertility (nonclassic CAH [NC-CAH]), and could influence sexual function and identity. AIM: The present study evaluated sexual function, gender identification, and partner preference in women with C-CAH and NC-CAH. METHODS: In a cross-sectional cohort analysis, 35 female patients with CAH were divided into 2 groups: C-CAH (salt-wasting/simple virilizing; n = 17) and NC-CAH (n = 18) according to genotype and phenotype. Sexual function and sexual distress were assessed using established questionnaires, including the Female Sexual Function Index. Phenotype (defined by signs of hyperandrogenism) was assessed clinically (Ferriman-Gallwey score) and with the ovulatory function index. CYP21A2 genotype was determined by Sanger sequencing and multiplex ligation-dependent probe amplification. Sexual function was also separately analyzed in the context of clinical signs of androgenization in women with (n = 13) and without acne (n = 22). OUTCOMES: The study outcomes were sexual function and sexual distress in relation to genotype, clinical signs of androgenization, and biochemical parameters. RESULTS: Women with NC-CAH had significantly lower orgasm scores, a trend toward lower sexual function with higher sexual distress, as well as biochemical evidence of hyperandrogenism (higher dehydroepiandrosterone sulfate and lower SHBG) and a trend toward more clinical signs of hyperandrogenism (hirsutism). Indicators of in utero and childhood androgen excess as well as the presence of acne in all patients were related to lower sexual function and higher sexual distress. Clinical signs of hyperandrogenism correlated well with cardiovascular and metabolic risk factors. CLINICAL TRANSLATION: Women with NC-CAH and women with clinical signs of hyperandrogenism demonstrated higher distress compared to women with C-CAH and women without clinical signs of hyperandrogenism, respectively, regarding different aspects of sexual function. CONCLUSIONS: These data underline the importance of early diagnosis and therapy initiation, especially in patients with NC-CAH. Schernthaner-Reiter MH, Baumgartner-Parzer S, Egarter HC, et al. Influence of Genotype and Hyperandrogenism on Sexual Function in Women With Congenital Adrenal Hyperplasia. J Sex Med 2019;16:1529-1540.

Comparative in situ analysis reveals the dynamic nature of sclerenchyma cell walls of the fern Asplenium rutifolium.

Background and Aims: A key structural adaptation of vascular plants was the evolution of specialized vascular and mechanical tissues, innovations likely to have generated novel cell wall architectures. While collenchyma is a strengthening tissue typically found in growing organs of angiosperms, a similar tissue occurs in the petiole of the fern Asplenium rutifolium. Methods: The in situ cell wall (ultra)structure and composition of this tissue was investigated and characterized mechanically as well as structurally through nano-indentation and wide-angle X-ray diffraction, respectively. Key Results: Structurally the mechanical tissue resembles sclerenchyma, while its biomechanical properties and molecular composition both share more characteristics with angiosperm collenchyma. Cell wall thickening only occurs late during cell expansion or after cell expansion has ceased. Conclusions: If the term collenchyma is reserved for walls that thicken during expansive growth, the mechanical tissue in A. rutifolium represents sclerenchyma that mimics the properties of collenchyma and has the ability to modify its mechanical properties through sclerification. These results support the view that collenchyma does not occur in ferns and most probably evolved in angiosperms.

Effect of sexual diary keeping and self-evaluation on female sexual function and depression: A pilot study.

OBJECTIVES: The aim of the trial was to assess the effect of self-evaluation and sexual diary keeping on female sexual function and depressive symptoms in women diagnosed with sexual dysfunction. METHODS: A single-arm non-randomised trial included 30 women (53 ± 7 years of age) with female sexual dysfunction (Female Sexual Function Index [FSFI] < 27) and a stable partnership duration of 5-40 years. Female sexual function was assessed by sexual, psychological and gynaecological history taking and validated questionnaires including the FSFI, Female Sexual Distress Scale (FSDS) and Hamilton Depression Scale (HDS), before and after 4 weeks of sexual diary keeping. RESULTS: A subjective improvement in communication of sexual problems was reported by 60% of participants; no participants reported any worsening of communication. FSFI and FSDS scores were, respectively, 18.0 ± 7.7 and 22.0 ± 10.0 at baseline and 20.2 ± 7.2 and 20.6 ± 11.5 after 4 weeks. HDS score decreased from 6.0 ± 4.0 at baseline to 4.4 ± 2.7 after 4 weeks (p = 0.042). CONCLUSIONS: Self-evaluation and sexual diary keeping may improve aspects of sexual life, such as couple communication, without a direct effect on variables measured with validated questionnaires on different domains of sexual function.

Multiple risk factor intervention reduces carotid atherosclerosis in patients with type 2 diabetes.

BACKGROUND: Patients with rapid progression of carotid intima media thickness (CIMT) were shown to have a higher future risk for cardiovascular events.The aim of this study was to investigate the impact of multiple risk factor intervention on CIMT progression and to establish whether new cardiovascular surrogate measurements would allow prediction of CIMT changes. MATERIALS AND METHODS: In this prospective, open, 2-years study, we included 97 patients with type 2 diabetes and at least two insufficiently treated cardiovascular risk factors, i.e. HbA1c > 7.5% (58 mmol/mol); LDL-cholesterol >3.1 mmol/l or blood pressure >140/90 mmHg. Treatment was intensified according to current guidelines over 3 months with the aim to maintain intensification over 2 years.The primary outcome was the change in CIMT after 2 years. We also assessed markers of mechanical and biochemical endothelial function and endothelial progenitor cells before and after 3 months of treatment intensification. For testing differences between before and after multifactorial treatment measurements we used either the paired student's t-test or the Wilcoxon signed-rank test, depending on the distribution of the data. Additional, explorative statistical data analysis was done on CIMT progression building a linear multivariate regression model. RESULTS: Blood glucose, lipids and blood pressure significantly improved during the first 3 months of intensified treatment, which was sustained over the 2-year study duration. Mean CIMT significantly decreased from baseline to 2 year (0.883 ± 0.120 mm vs. 0.860 ± 0.130 mm; p = 0.021). None of the investigated surrogate measures, however, was able to predict changes in IMT early after treatment intensification. CONCLUSIONS: Intensification of risk factor intervention in type 2 diabetes results in CIMT regression over a period of 2 years. None of the biomarkers used including endothelial function parameters or endothelial progenitor cells turned out to be useful to predict CIMT changes. TRIAL REGISTRATION: Clinical Trial Registration - Unique identifier: NCT00660790.

A Case of simultaneous occurrence of Marine - Lenhart syndrome and a papillary thyroid microcarcinoma.

BACKGROUND: Marine-Lenhart syndrome is defined as the co-occurrence of Graves' disease and functional nodules. The vast majority of autonomous adenomas are benign, whereas functional thyroid carcinomas are considered to be rare. Here, we describe a case of simultaneous occurrence of Marine-Lenhart syndrome and a papillary microcarcinoma embedded in a functional nodule. CASE PRESENTATION: A 55 year-old, caucasian man presented with overt hyperthyroidism (thyrotropin (TSH) <0.01 µIU/L; free thyroxine (FT4) 3.03 ng/dL), negative thyroid peroxidase and thyroglobulin autoantibodies, but elevated thyroid stimulating hormone receptor antibodies (TSH-RAb 2.6 IU/L). Ultrasound showed a highly vascularized hypoechoic nodule (1.1 × 0.9 × 2 cm) in the right lobe, which projected onto a hot area detected in the 99mtechnetium thyroid nuclear scan. Overall uptake was increased (4.29%), while the left lobe showed lower tracer uptake with no visible background-activity, supporting the notion that both Graves' disease and a toxic adenoma were present. After normal thyroid function was reinstalled with methimazole, the patient underwent thyroidectomy. Histological work up revealed a unifocal papillary microcarcinoma (9 mm, pT1a, R0), positively tested for the BRAF V600E mutation, embedded into the hyperfunctional nodular goiter. CONCLUSIONS: Neither the finding of an autonomously functioning thyroid nodule nor the presence of Graves' disease rule out papillary thyroid carcinoma.

Adhesives free bark panels: An alternative application for a waste material.

The proportion of bark in tree trunks is in the range of ~ 10-20%. This large amount of material is currently mainly considered as a by- or even waste-product by the timber processing industry. Recently, efforts towards the use of bark have been made, e.g. as a raw material to harvest different chemical compounds or as an additive for wood particle boards. Our motivation for this work was to keep the bark in an almost natural state and explore alternative processes and applications for use. The traditional method of de-barking tree trunks by peeling was used to harvest large bark pieces. Two pieces of peeled bark were placed crosswise, with the rhytidom side (outer bark) facing each other. After different conditioning steps, bark pieces were hot pressed to panels without adding adhesives. These experiments on bark samples of different Central European tree species suggest that production of panels with species dependent properties is possible and feasible. This is a step towards producing sustainable panels by using a natural waste material, while retaining its beneficial structure and its natural chemical composition.

Curvature in Biological Systems: Its Quantification, Emergence, and Implications across the Scales.

Surface curvature both emerges from, and influences the behavior of, living objects at length scales ranging from cell membranes to single cells to tissues and organs. The relevance of surface curvature in biology is supported by numerous experimental and theoretical investigations in recent years. In this review, first, a brief introduction to the key ideas of surface curvature in the context of biological systems is given and the challenges that arise when measuring surface curvature are discussed. Giving an overview of the emergence of curvature in biological systems, its significance at different length scales becomes apparent. On the other hand, summarizing current findings also shows that both single cells and entire cell sheets, tissues or organisms respond to curvature by modulating their shape and their migration behavior. Finally, the interplay between the distribution of morphogens or micro-organisms and the emergence of curvature across length scales is addressed with examples demonstrating these key mechanistic principles of morphogenesis. Overall, this review highlights that curved interfaces are not merely a passive by-product of the chemical, biological, and mechanical processes but that curvature acts also as a signal that co-determines these processes.

Reorientation of cellulose nanowhiskers in agarose hydrogels under tensile loading.

Agarose hydrogels filled with cellulose nanowhiskers were strained in uniaxial stretching under different humidity conditions. The orientation of the cellulose whiskers was examined before and after testing with an X-ray laboratory source and monitored in situ during loading by synchrotron X-ray diffraction. The aim of this approach was to determine the process parameters for reorienting the cellulose nanowhiskers toward a preferential direction. Results show that a controlled drying of the hydrogel is essential to establish interactions between the matrix and the cellulose nanowhiskers which allow for a stress transfer during stretching and thereby promote their alignment. Rewetting of the sample after reorientation of the cellulose nanowhiskers circumvents a critical increase of stress. This improves the extensibility of the hydrogel and is accompanied by a further moderate alignment of the cellulose nanowhiskers. Following this protocol, cellulose nanowhiskers with an initial random distribution can be reoriented toward a preferential direction, creating anisotropic nanocomposites.

Cellulose lattice strains and stress transfer in native and delignified wood.

Small specimens of spruce wood with different degrees of delignification were studied using in-situ tensile tests and simultaneous synchrotron X-ray diffraction to reveal the effect of delignification and densification on their tensile properties at relative humidities of 70-80 %. In addition to mechanical properties, these analyses yield the ratio of strains in the cellulose crystals and in the bulk, which reflects the stress-transfer to crystalline cellulose. While the specific modulus of elasticity slightly increases from native wood by partial or complete delignification, the lattice strain ratio does not show a significant change. This could indicate a compensatory effect from the decomposition of the amorphous matrix by delignification and from a tighter packing of cellulose crystals that would increase the stress transfer. The reduced strain to failure and maximum lattice strain of delignified specimens suggests that the removal of lignin affects the stress-strain behavior with fracture at lower strain levels.

Wood and the Activity of Dead Tissue.

Wood is a prototypical biological material, which adapts to mechanical requirements. The microarchitecture of cellulose fibrils determines the mechanical properties of woody materials, as well as their actuation properties, based on absorption and desorption of water. Herein it is argued that cellulose fiber orientation corresponds to an analog code that determines the response of wood to humidity as an active material. Examples for the harvesting of wood activity, as well as bioinspiration, are given.

Microstructural features influencing the mechanical performance of the Brazil nut (Bertholletia excelsa) mesocarp.

Brazil nut (Bertholletia excelsa) fruits are capable of resisting high mechanical forces when released from trees as tall as 50 m, as well as during animal dispersal by sharp-teethed rodents. Thick mesocarp plays a crucial part in seed protection. We investigated the role of microstructure and how sclereids, fibers, and voids affect nutshell performance using compression, tensile and fracture toughness tests. Fractured specimens were analyzed through scanning electron microscopy (SEM) and microtomography (microCT). Mesocarp showed high deformability (strain at max. stress of ~30%) under compression loading, a critical tensile strength of ~24.9 MPa, a Weibull modulus of ~3, and an elastic modulus of ~2 GPa in the tensile test. The fracture toughness, estimated through the work of fracture of SENB tests, reached ~2 kJ/m2. The thick and strong walls of mesocarp cells, with a weaker boundary between them (compound middle lamella), promote a tortuous intercellular crack path. Several toughening mechanisms, such as crack deflection, breaking of fiber bundles, fiber pullout and bridging as well as crack branching, occur depending on how fiber bundles and voids are oriented.

Repetitive hygroscopic snapping movements in awns of wild oats.

Wild oat (Avena sterilis) is a very common annual plant species. Successful seed dispersion support its wide distribution in Africa, Asia and Europe. The seed dispersal units are made of two elongated stiff awns that are attached to a pointy compartment containing two seeds. The awns bend and twist with changes in humidity, pushing the seeds along and into the soil. The present work reveals the material structure of the awns, and models their functionality as two-link robotic arms. Based on nano-to-micro structure analyses the bending and twisting hygroscopic movements are explained. The coordinated movements of two sister awns attached to one dispersal unit were followed. Our work shows that sister awns intersect typically twice every wetting-drying cycle. Once the awns cross each other, epidermal silica hairs are suggested to lock subsequent movements, resulting in stress accumulation. Sudden release of the interlocked awns induces jumps of the dispersal unit and changes in its movement direction. Our findings propose a new role to epidermis silica hairs and a new facet of wild oat seed dispersion. Reversible jumping mechanism in multiple-awn seed dispersal units may serve as a blueprint for reversibly jumping robotic systems. STATEMENT OF SIGNIFICANCE: The seed dispersal unit of wild oats carries two elongated stiff awns covered by unidirectional silica hairs. The awns bend and twist with changes in humidity, pushing the seed capsule along and into the ground. We studied structures constructing the movement mechanism and modeled the awn as a two-link robotic arm. We show that sister awns, attached to the same seed capsule, intersect twice every drying cycle. Once the awns cross each other, the epidermal silica hairs are suggested to lock any subsequent movements, causing stress accumulation. Sudden release of the interlocked awns may cause the dispersal unit to jump and change its direction. Our findings suggest a new role to silica hairs and a new dispersal mechanism in multiple-awn seed dispersal units.

Penile Hemodynamic Response to Phosphodiesterase Type V Inhibitors after Cavernosal Sparing Inflatable Penile Prosthesis Implantation: A Prospective Randomized Open-Blinded End-Point (PROBE) Study.

Forceful corporal dilatation amidst penile prosthesis implantation may injure cavernosal arteries compromising penile vasculature. In this study, we aimed to compare the conventional and cavernosal sparing techniques regarding cavernosal artery preservation. Overall, 33 patients underwent inflatable penile prosthesis implantation with Coloplast Titan Touch® three-piece inflatable penile implants. 16 patients had conventional implantations with serial vigorous dilatations, while 17 patients were implanted with the cavernosal sparing technique, consisting of a single minimal corporal dilatation after an intraoperative intracavernosal injection (ICI) of Alprostadil. Postoperatively, a penile duplex Doppler ultrasound study was performed. Whenever a cavernosal artery was spared and thus successfully probed, its hemodynamics were studied before and after an oral administration of a phosphodiesterase type 5 inhibitor (PDE5i). A cavernosal artery was successfully probed in 16/17 (94%) of patients in the cavernosal sparing group compared to 5/16 (31%) of patients in the conventional group with a significant statistical difference (P=0.001). This demonstrated that the cavernosal sparing technique was superior to the conventional approach in preserving the cavernosal artery (odds ratio 35.2, 95% IC 3.5-344.2; P=0.0022). Whenever a cavernosal artery could be probed, its hemodynamic responsiveness was also preserved. This trial is registered with NCT03733860.

Cellulose microfibril orientation of Picea abies and its variability at the micron-level determined by Raman imaging.

The functional characteristics of plant cell walls depend on the composition of the cell wall polymers, as well as on their highly ordered architecture at scales from a few nanometres to several microns. Raman spectra of wood acquired with linear polarized laser light include information about polymer composition as well as the alignment of cellulose microfibrils with respect to the fibre axis (microfibril angle). By changing the laser polarization direction in 3 degrees steps, the dependency between cellulose and laser orientation direction was investigated. Orientation-dependent changes of band height ratios and spectra were described by quadratic linear regression and partial least square regressions, respectively. Using the models and regressions with high coefficients of determination (R(2) > 0.99) microfibril orientation was predicted in the S1 and S2 layers distinguished by the Raman imaging approach in cross-sections of spruce normal, opposite, and compression wood. The determined microfibril angle (MFA) in the different S2 layers ranged from 0 degrees to 49.9 degrees and was in coincidence with X-ray diffraction determination. With the prerequisite of geometric sample and laser alignment, exact MFA prediction can complete the picture of the chemical cell wall design gained by the Raman imaging approach at the micron level in all plant tissues.

Topological Interlocking and Geometric Stiffening as Complementary Strategies for Strong Plant Shells.

Many organisms encapsulate their embryos in hard, protective shells. While birds and reptiles largely rely on mineralized shells, plants often develop highly robust lignocellulosic shells. Despite the abundance of hard plant shells, particularly nutshells, it remains unclear which fundamental properties drive their mechanical stability. This multiscale analysis of six prominent (nut)shells (pine, pistachio, walnut, pecan, hazelnut, and macadamia) reveals geometric and structural strengthening mechanisms on the cellular and macroscopic length scales. The strongest tissues, found in walnut and pistachio, exploit the topological interlocking of 3D-puzzle cells and thereby outperform the fiber-reinforced structure of macadamia under tensile and compressive loading. On the macroscopic scale, strengthening occurs via an increased shell thickness, spherical shape, small size, and a lack of extended sutures. These functional interrelations suggest that simple geometric modifications are a powerful and resource-efficient strategy for plants to enhance the fracture resistance of entire shells and their tissues. Understanding the interplay between structure, geometry, and mechanics in hard plant shells provides new perspectives on the evolutionary diversification of hard seed coats, as well as insights for nutshell-based material applications.

Stress generation in the tension wood of poplar is based on the lateral swelling power of the G-layer.

The mechanism of active stress generation in tension wood is still not fully understood. To characterize the functional interdependency between the G-layer and the secondary cell wall, nanostructural characterization and mechanical tests were performed on native tension wood tissues of poplar (Populus nigra x Populus deltoids) and on tissues in which the G-layer was removed by an enzymatic treatment. In addition to the well-known axial orientation of the cellulose fibrils in the G-layer, it was shown that the microfibril angle of the S2-layer was very large (about 36 degrees). The removal of the G-layer resulted in an axial extension and a tangential contraction of the tissues. The tensile stress-strain curves of native tension wood slices showed a jagged appearance after yield that could not be seen in the enzyme-treated samples. The behaviour of the native tissue was modelled by assuming that cells deform elastically up to a critical strain at which the G-layer slips, causing a drop in stress. The results suggest that tensile stresses in poplar are generated in the living plant by a lateral swelling of the G-layer which forces the surrounding secondary cell wall to contract in the axial direction.