Synthetic Components Research Articles

Growth and site-specific organization of micron-scale biomolecular devices on living mammalian cells

Mesoscale molecular assemblies on the cell surface, such as cilia and filopodia, integrate information, control transport and amplify signals. Designer cell-surface assemblies could control these cellular functions. Such assemblies could be constructed from synthetic components ex vivo, making it possible to form such structures using modern nanoscale self-assembly and fabrication techniques, and then oriented on the cell surface. Here we integrate synthetic devices, micron-scale DNA nanotubes, with mammalian cells by anchoring them by their ends to specific cell surface receptors. These filaments can measure shear stresses between 0-2 dyn/cm2, a regime important for cell signaling. Nanotubes can also grow while anchored to cells, thus acting as dynamic cell components. This approach to cell surface engineering, in which synthetic biomolecular assemblies are organized with existing cellular architecture, could make it possible to build new types of sensors, machines and scaffolds that can interface with, control and measure properties of cells.

Photo-cross-linked Gelatin Glycidyl Methacrylate/N-Vinylpyrrolidone Copolymeric Hydrogel with Tunable Mechanical Properties for Ocular Tissue Engineering Applications

Corneal transplantation is currently the primary treatment for corneal blindness. However, severe global scarcity of donor corneas is driving the scientific community to find novel solutions. One potential solution is to replace the damaged tissue with a biocompatible artificial cornea. Here, gelatin glycidyl methacrylate (GM) and N-vinylpyrrolidone (VP) were cocrosslinked to afford a hybrid bicomponent copolymeric hydrogel with excellent mechanical, structural, and biological properties. Our studies showed that the GM/VP ratio can be adjusted to generate a construct with high tensile modulus and strength of 1.6 and 1.0 MPa, respectively, compared to 14 and 7.5 MPa for human cornea. The construct can tolerate up to 22.4 kPa pressure before retention sutures can tear through it. Due to the presence of a synthetic component, it has a significantly higher stability against collagenase induced degradation, yet it is biocompatible and promotes cellular adhesion, proliferation, and migration under in vitro settings.

Poly(2-alkyl-2-oxazoline)-Heparin Hydrogels-Expanding the Physicochemical Parameter Space of Biohybrid Materials.

Poly(ethylene glycol) (PEG)-glycosaminoglycan (GAG) hydrogel networks are established as very versatile biomaterials. Herein, the synthetic gel component of the biohybrid materials is systematically varied by combining different poly(2-alkyl-2-oxazolines) (POx) with heparin applying a Michael-type addition crosslinking scheme: POx of gradated hydrophilicity and temperature-responsiveness provides polymer networks of distinctly different stiffness and swelling. Adjusting the mechanical properties and the GAG concentration of the gels to similar values allows for modulating the release of GAG-binding growth factors (VEGF165 and PDGF-BB) by the choice of the POx and its temperature-dependent conformation. Adsorption of fibronectin, growth of fibroblasts, and bacterial adhesion scale with the hydrophobicity of the gel-incorporated POx. In vitro hemocompatibility tests with freshly drawn human whole blood show advantages of POx-based gels compared to the PEG-based reference materials. Biohybrid POx hydrogels can therefore enable biomedical technologies requiring GAG-based materials with customized and switchable physicochemical characteristics.

Adulteration of Essential Oils: A Multitask Issue for Quality Control. Three Case Studies: Lavandula angustifolia Mill., Citrus limon (L.) Osbeck and Melaleuca alternifolia (Maiden & Betche) Cheel.

The quality control of essential oils (EO) principally aims at revealing the presence of adulterations and at quantifying compounds that are limited by law by evaluating EO chemical compositions, usually in terms of the normalised relative abundance of selected markers, for comparison to reference values reported in pharmacopoeias and/or international norms. Common adulterations of EO consist of the addition of cheaper EO or synthetic materials. This adulteration can be detected by calculating the percent normalised areas of selected markers or the enantiomeric composition of chiral components. The dilution of the EO with vegetable oils is another type of adulteration. This adulteration is quite devious, as it modifies neither the qualitative composition of the resulting EO nor the marker’s normalised percentage abundance, which is no longer diagnostic, and an absolute quantitative analysis is required. This study aims at verifying the application of the two above approaches (i.e., normalised relative abundance and absolute quantitation) to detect EO adulterations, with examples involving selected commercial EO (lavender, bergamot and tea tree) adulterated with synthetic components, EO of different origin and lower economical values and heavy vegetable oils. The results show that absolute quantitation is necessary to highlight adulteration with heavy vegetable oils, providing that a reference quantitative profile is available.

Quercetin Supplementation and COVID-19

Quercetin is an antioxidant, detox, and anti-inflammatory agent, which may help lower inflammation as well as reduce toxic effects. It has been argued that vaccines have potential risks of local and systemic inflammatory responses and toxic effects of synthetic nucleosides and components for vaccine delivery. Administration of substances such as Quercetin may then mitigate these effects. It has similarly been argued that substances such as Quercetin may reduce the efficacy of vaccines, which works in building an immune response to produce antibodies. Under this other perspective, the assumption of Quercetin should be avoided when receiving vaccines. The purpose of this paper is to analyze the information available to understand if Quercetin may mitigate the damage from novel coronavirus disease 2019 (COVID-19) vaccines, or also reduce their efficacy.

Challenges towards Targeted Drug Delivery in Cancer Nanomedicines

Despite cancer nanomedicine celebrates already thirty years since its introduction, together with the achievements and progress in cancer treatment area, it still undergoes serious disadvantages that must be addressed. Since the first observation that macromolecules tend to accumulate in tumor tissue due to fenestrated endothelial of vasculature, considered as the “royal gate” in drug delivery field, more than dozens of nanoformulations have been approved and introduced into the practice for cancer treatment. Lipid, polymeric, and hybrid nanocarriers are biocompatible nano-drug delivery systems (NDDs) having suitable physicochemical properties and modulate payload release in response to specific chemical or physical stimuli. Biopharmaceutical properties of NDDs and their efficacy in animal models and humans can significantly affect their impact and perspective in nanomedicine. One of the future directions could be focusing on personalized cancer treatment, considering the heterogeneity and complexity of each patient tumor tissue and the designing of multifunctional targeted NDDs combining synthetic nanomaterials and biological components, like cellular membranes, circulating proteins, RNAi/DNAi, which enforce the efficacy of NDDs and boost their therapeutic effect.

Anisotropy of magnetic susceptibility, gravimetry and geochronology of the Cerne granite, Ribeira Belt, southern Brazil

The Cerne granite is an elongated pluton in the NE-SW direction, parallel with the Ribeira Belt trend. This Neoproterozoic massif crosscuts supracrustal metamorphic rocks and has been considered late to post orogenic in the Ribeira belt evolution (Apiaí domain). The Lancinha and Morro Agudo shear zones are the major tectonic structures that frame the studied area. The southern border of the pluton is deformed by the dextral Cerne brittle-plastic shear zone, which is considered a Lancinha shear zone synthetic component. The intrusion consists mainly of fine-to medium-grained alkali feldspar granites and quartz alkali feldspar syenites. Conversely to its elongated shape, striking N20E, the rocks display isotropic structure. Analyzing field data, and integrating with petrography, gravimetry profiles, anisotropy of magnetic susceptibility (AMS) and geochronology techniques, we sought to contribute to understand the architecture of the Cerne granite and its emplacement mechanisms. The rocks display isotropic structure and very locally an incipient preferred orientation of biotite crystals. Quartz grains do not show preferred orientation but undulose extinction, and bulging-related recrystallization features are more commonly observed on low-temperature mylonites located close to the southern border of the pluton. The Cerne granite gravimetric data show two roots of two inverted teardrop-shaped plutons. ASM fabric is mostly controlled by coarse-grained magnetite, with a mean susceptibility of 7.15 mSI. The magnetic foliation (K3) shows a concentric arrangement shallowly dipping and the magnetic lineation (K1) displays subhorizontal plunging. AMS ellipsoids varies from neutral to oblate (T ≥ 0) in 75% of the sites. Concentric magnetic foliations and lineations seem to follow the plutons boundaries and reflect mostly magma chamber dynamics. The set of data suggests that the Cerne magma emplacement occurred in a place of local distension stresses associated with sinistral strike-slip system. Deep-seated tension gash probably controlled the Cerne granite ascent. SHRIMP U–Pb zircon dating provided an age of 614 ± 8 Ma attributed to the emplacement and crystallization of the granite.

Study of the Dyeing Properties of Annatto and Ultrafiltrated Annatto as Colourants for Natural Fibres

ABSTRACT Cotton and wool fabrics have been dyed in the absence of mordants with annatto and ultrafiltrated annatto powder. Τhe optimum dyeing conditions were determined as far as the quantity of salt and dyebath pH are concerned. The dyeing properties of annatto and ultrafiltrated annatto were studied by monitoring the dye uptake in various time intervals and temperatures of dyeing. The adsorption isotherms for both annatto and ultrafiltrated annatto were studied. It was found that adsorption of annatto on cotton follows a BET-type adsorption isotherm indicating a multilayer formation of molecules onto cotton, whereas the adsorption of ultrafiltrated annatto follows a Freundlich-type monolayer adsorption. Adsorption of both annatto and ultrafiltrated annatto on cotton occurs through the formation of Van der Waals forces between annatto molecules and cotton substrate. The adsorption on wool of both annatto and ultrafiltrated annatto follows a Freudlich-type adsorption isotherm indicating a monolayer formation occurring between the positively-charged wool substrate and the negatively-charged annatto molecules. The dyeing behavior of natural annatto resembles that of the synthetic direct and acid dyes commonly applied for dyeing cotton and wool. Thus, annatto and ultrafiltrated annatto can successfully replace the synthetic yellow dye component in the dyeing of cotton and wool fibers.

Pyrolysis and combustion of community masks: Thermogravimetric analyses, characterizations, gaseous emissions, and kinetic modeling

Used community masks are often thrown away or scattered in the environment. In addition to the unsightly aspect of such waste, these masks are a diffuse source of pollution because of some of their synthetic components: polypropylene, polyethylene terephthalate (PET), polyamide 6, polyamide 66, and elastane. These diffuse sources of pollution must be processed in an appropriate way, once they are collected. Among such processes, pyrolysis or combustion are to be explored.In the present study, five different masks were characterized before being submitted to pyrolysis and combustion experiments performed in a thermobalance under temperature ramps of 5, 10, 15, or 20 °C/min. Kinetic modeling of these pyrolysis or combustion processes was performed using the EIPR model because each mask contains different layers or components. The optimal values of the kinetic parameters were compared for the five masks and compared with that of their components. In complement to the thermogravimetric experiments, the main gaseous emissions (CO, CO2, THC, NO and NO2) were continuously measured during combustion tests in a horizontal oven. The gaseous emissions and mass rates curves were compared for each mask.

Effects of Water and Chemical Solutions Ageing on the Physical, Mechanical, Thermal and Flammability Properties of Natural Fibre-Reinforced Thermoplastic Composites.

Biocomposites comprising a combination of natural fibres and bio-based polymers are good alternatives to those produced from synthetic components in terms of sustainability and environmental issues. However, it is well known that water or aqueous chemical solutions affect natural polymers/fibres more than the respective synthetic components. In this study the effects of water, salt water, acidic and alkali solutions ageing on water uptake, mechanical properties and flammability of natural fibre-reinforced polypropylene (PP) and poly(lactic acid) (PLA) composites were compared. Jute, sisal and wool fibre- reinforced PP and PLA composites were prepared using a novel, patented nonwoven technology followed by the hot press method. The prepared composites were aged in water and chemical solutions for up to 3 week periods. Water absorption, flexural properties and the thermal and flammability performances of the composites were investigated before and after ageing each process. The effect of post-ageing drying on the retention of mechanical and flammability properties has also been studied. A linear relationship between irreversible flexural modulus reduction and water adsorption/desorption was observed. The aqueous chemical solutions caused further but minor effects in terms of moisture sorption and flexural modulus changes. PLA composites were affected more than the respective PP composites, because of their hydrolytic sensitivity. From thermal analytical results, these changes in PP composites could be attributed to ageing effects on fibres, whereas in PLA composite changes related to both those of fibres present and of the polymer. Ageing however, had no adverse effect on the flammability of the composites.

Polyketone-Based Molecular Ropes as Versatile Components for Functional Materials

Abstract This account describes recent aspects of the polyketone-based synthesis of functional molecules. Polyketones are rope-like compounds that combine conformational flexibility with reaction diversity. Although natural-type polyketones, bearing a repeating 1,3-diketone sequence, are difficult to handle as synthetic components owing to complex tautomerism and rapid intramolecular cyclization, the recent development of 1,3- and 1,4-diketone hybrid sequences has enabled access to stable, discrete polyketones for further synthetic functionalization. Various molecular structures with functional properties can be generated from the polyketone chains through rope manipulations, such as bending and coiling. Herein, we introduce their synthesis and structures, focusing on the functionality derived from π-conjugation and metal ion coordination with polyketone derivatives, such as solid-state photo emission, metal-ion conduction, and adsorption.

Prolonged Prothrombin Time in DIC: Contributions of Excess Thrombin and Fibrinogen Degradation Products

BackgroundProthrombin time (PT) is a clot-based assay that remains the clinical standard for diagnosis of coagulopathy. Prolongation of PT can be attributed to decreased fibrinogen (Fg) and dysfibrinogenemia but is commonly interpreted as a deficiency in thrombin (FIIa) generation. Paradoxically, conditions in which PT becomes prolonged (e.g., DIC, trauma) are associated with increased FIIa generation. This suggests that prolonged PT may be misleading, and efforts to improve PT in hypocoagulopathy by promoting FIIa generation may be misguided. We modeled the effects on fibrin polymerization related to varying FIIa, Fg, and Fg degradation products (FDPs, such as D-Dimer) in vitro as a platform for understanding the mechanisms underlying hypocoagulopathy.MethodsIn vitro studies were conducted using prothrombin-deficient plasmas, synthetic plasma (Fg and coagulation factors in HEPES buffered saline), and re-assembled whole blood (plasma with fresh RBCs and platelets). Concentrations of synthetic plasma components were varied to model coagulopathic states (Shaz et al. J Trauma 2011;70(6):1401-7; Johansson et al. Crit Care. 2011;15(6):R272). Assays included thromboelastography (TEG), fibrin polymerization (turbidimetry), FIIa generation (calibrated automated thrombogram, CAT), rheology, and PT/INR (Stago STA-R Evolution).ResultsIn vitro simulations of coagulopathy illustrated the significance of each factor on coagulation function. A dose response of FIIa (50-1000 nM) in prothrombin-deficient plasma demonstrated that beyond the normal FIIa range (100-200 nM), excess FIIa did not enhance clot characteristics; in fact, TEG maximum amplitude (clot strength) decreased in a FIIa dose-dependent fashion versus the equivalent dose of prothrombin (p < .001).In synthetic plasma, a similar dose-dependent FIIa effect on fibrin polymerization peak was shown at Fg concentrations of 5 and 3 mg/ml; depleting Fg to 1 mg/ml also showed this effect, but at this level clot formation was extremely poor even with optimal FIIa (Figure 1). The exponential turbidity rise as Fg converts to fibrin resulted in a time-to-peak of ~60 s for all FIIa conc. (time-to-half-peak was < 15 s). For equivalent Fg, increasing FIIa from 120 nM (peak in normal pooled blood) to 250 nM (peak in hemorrhaged coagulopathic patient; Cardenas et al. J Trauma. 2014;77(6):839-45) resulted in decreased total fibrin polymerization (p < .001 between 120 and 250 nM FIIa for all Fg values ≥ 150 mg/dl; Figure 2). With rheology, 150 nM FIIa resulted in rapidly formed clots with a significant decrease in stiffness vs. clots allowed to form by contact activation (135 Pa vs. 4.5 Pa with FIIa; p < .001).When RBCs and platelets were present, the same FIIa dose-dependent effect existed but was highly mitigated with increasing hematocrit (from 0 to 40%). The inhibitory effect of increased FIIa on fibrin polymerization was enhanced by addition of exogenous FDPs in a model of hyperfibrinolysis.ConclusionsProthrombin levels typically drop following severe hemorrhage but are sufficient to produce the active enzyme. These in vitro studies show that the prolongation of PT found in hypocoagulopathy may be a misleading diagnostic; increasing FIIa levels may improve PT but does not improve clot function. The addition of excess FIIa, while rapidly initiating clot formation, results in poorly formed clots.Excess FIIa generated during injury and hemorrhage combined with production of FDPs is mimicked in these in vitro studies, leading to a hypocoagulable state. Additionally, changes in Fg have profound effects on coagulation within the range of 100-300 mg/dl. The inhibitory effects of excess FIIa are worsened with insufficient Fg, aggravated further by D-dimer. Therefore, increases in PT under these circumstances may be attributed to poor fibrin polymerization.Hyperfibrinolysis is problematic, not just because of the breakdown of hemostasis-providing clots, but also due to the effects that FDPs have on future clot formation, particularly amplified at low Fg levels. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Optimization of an Untargeted DART-HRMS Method Envisaging Identification of Potential Markers for Saffron Authenticity Assessment.

Saffron is one of the most expensive agricultural products in the world and as such, the most commonly adulterated spice, with undeclared plant-based surrogates or synthetic components simulating color and morphology. Currently, saffron quality is certificated in the international trade market according to specific ISO guidelines, which test aroma, flavor, and color strength. However, it has been demonstrated that specific adulterants such as safflower, marigold, or turmeric up to 20% (w/w) cannot be detected under the prescribed approach; therefore, there is still a need for advanced and sensitive screening methods to cope with this open issue. The current investigation aims to develop a rapid and sensitive untargeted method based on an ambient mass spectrometry ionization source (DART) and an Orbitrap™high-resolution mass analyzer to discriminate pure and adulterated saffron samples with either safflower or turmeric. The metabolic profiles of pure and adulterated model samples prepared at different inclusion levels were acquired. Unsupervised multivariate analysis was carried out based on hierarchical cluster analysis and principal component analysis as first confirmation of the discriminating potential of the metabolic profile acquired under optimized DART-HRMS conditions. In addition, a preliminary selection of potential markers for saffron authenticity was accomplished, identifying compounds able to discriminate the type of adulteration down to a concentration level of 5%.

Performance regulation of silica aerogel powder synthesized by a two-step Sol-gel process with a fast ambient pressure drying route

This paper proposed a timesaving route for preparing silica aerogel powder with TEOS as a precursor. Thermal insulating super hydrophobic silica aerogel powder was synthesized by combining two-step Sol-gel reaction with a fast ambient pressure drying process. Silica Sol-gel was formed after catalytic reaction by oxalic acid and NH4OH, and then turned to be hydrophobic aerogel through further surface modification (only three hours with no solvent exchange process) and drying process. By optimizing every tiny trace of synthetic component, the obtained silica aerogel powder exhibits excellent properties, such as low apparent density (0.212 g/cm3) and thermal conductivity (0.053 W/mK), as well as high BET surface area (769.86 m2/g) and water contact angle (149.0 °). This work presents a timesaving method for synthesizing thermal insulating hydrophobic silica aerogel powder.

Influence of the Medium Composition and the Culture Conditions on Surfactin Biosynthesis by a Native Bacillus subtilis natto BS19 Strain.

An effective microbial synthesis of surfactin depends on the composition of the culture medium, the culture conditions and the genetic potential of the producer strain. The aim of this study was to evaluate the suitability of various medium components for the surfactin producing strain and to determine the impact of the culture conditions on the biosynthesis of surfactin isoforms by the newly isolated native strain Bacillus subtilis natto BS19. The efficiency of surfactin biosynthesis was determined by measuring the surface tension of the medium before and after submerged culture (SmF) and by qualitative and quantitative analysis of the obtained compound by high performance liquid chromatography. The highest efficiency of surfactin biosynthesis was achieved using starch as the carbon source and yeast extract as the nitrogen source at pH 7.0 and 37 °C. Potato peelings were selected as an effective waste substrate. It was shown that the increase in the percentage of peel extract in the culture medium enhanced the biosynthesis of surfactin (mg/L) (2–30.9%; 4–46.0% and 6–58.2%), while reducing surface tension of the medium by about 50%. The obtained results constitute a promising basis for further research on biosynthesis of surfactin using potato peelings as a cheap alternative to synthetic medium components.

No sharp line between the natural and the synthetic: biothetics and challenges to regulation

The code of human life stored in our cells is being extracted and transformed into biologically functional tissues at the same time it is also spawned with different synthetic materials that support those cells to mature and grow. Such products are essential of hybrid nature as they combine autologous and synthetic components, and thus making these products (that author labels as biothetics) difficult to categorize or put under existing know legal frameworks. This paper offers a brief review of the ethical, legal and social implications that regulators should be aware of. It also reflects on the bioconstitutional tensions that arise when novel technologies challenge the understanding of relations between our bodies, life and constitutions. By doing so, the paper examines the neoliberal underpinnings in the regulation of such a relationship.

Self-Organizing Microdroplet Protocells Displaying Light-Driven Oscillatory and Morphological Evolution.

The development of synthetic systems that enable the sustained active self-assembly of molecular blocks to mimic the complexity and dynamic behavior of living systems is of great interest in elucidating the origins of life, understanding the basic principles behind biological organization, and designing active materials. However, it remains a challenge to construct microsystems with dynamic behaviors and functions that are connected to molecular self-assembly processes driven by external energy. Here, an active self-assembly of microdroplet protocells with dynamic structure and high structural complexity through living radical polymerization under constant energy flux is reported. The active microdroplet protocells exhibit nonlinear behaviors including oscillatory growth and shrinkage. This relies on the transient stabilization of molecular assembly, which can channel the inflow of energy through noncovalent interactions of pure synthetic components. The intercommunication of microdroplet protocells through stochastic fusion leads to the formation of a variety of dynamic and higher-order biomimetic microstructures. This work constitutes an important step toward the realization of autonomous and dynamic microsystems and active materials with life-like properties.

Synthetic blood and blood products for combat casualty care and beyond.

Synthetic biology adopts an engineering design approach to create innovative treatments that are reliable, scalable, and customizable to individual patients. Interest in substitutes for allogenic blood components, primarily red blood cells and platelets, increased in the 1980s because of concerns over infectious disease transmission. However, only now, with emerging synthetic approaches, are such substitutes showing genuine promise. Affordable alternatives to donated blood would be of enormous benefit worldwide. Several approaches to replacing the oxygen-carrying function of red cells are under advanced investigation. Hemoglobin-based oxygen carriers incorporate modifications to reduce the renal toxicity and nitric oxide scavenging of free hemoglobin. While use of earlier-generation hemoglobin-based oxygen carriers may be limited to circumstances in which blood transfusion is not an option, recent advances in chemical modification of hemoglobin may eventually overcome such problems. Another approach encases hemoglobin molecules in biocompatible synthetic nanoparticles. An alternative is the ex vivo production of red cells in bioreactors, with or without genetic manipulation, that offers the potential of a universal donor product. Various strategies to manufacture synthetic platelets are also underway, ranging from simple phospholipid liposomes encapsulating adenosine diphosphate and decorated with fibrinogen fragments, to more complex capsules with multiple receptor peptide sequences. Ex vivo production of platelets in bioreactors is also possible including, for example, platelets derived from induced pluripotent stem cells that are differentiated into a megakaryocytic lineage. Prior to clinical use, trials assessing synthetic blood components must evaluate meaningful safety and effectiveness outcomes in relatively large numbers of critically ill patients. Overcoming these challenges may be as much a hurdle as product design. This article reviews the state of the science of the synthetic biology approach to developing blood component substitutes.

Biohybrid soft robots with self-stimulating skeletons.

Bioinspired hybrid soft robots that combine living and synthetic components are an emerging field in the development of advanced actuators and other robotic platforms (i.e., swimmers, crawlers, and walkers). The integration of biological components offers unique characteristics that artificial materials cannot precisely replicate, such as adaptability and response to external stimuli. Here, we present a skeletal muscle-based swimming biobot with a three-dimensional (3D)-printed serpentine spring skeleton that provides mechanical integrity and self-stimulation during the cell maturation process. The restoring force inherent to the spring system allows a dynamic skeleton compliance upon spontaneous muscle contraction, leading to a cyclic mechanical stimulation process that improves the muscle force output without external stimuli. Optimization of the 3D-printed skeletons is carried out by studying the geometrical stiffnesses of different designs via finite element analysis. Upon electrical actuation of the muscle tissue, two types of motion mechanisms are experimentally observed: directional swimming when the biobot is at the liquid-air interface and coasting motion when it is near the bottom surface. The integrated compliant skeleton provides both the mechanical self-stimulation and the required asymmetry for directional motion, displaying its maximum velocity at 5 hertz (800 micrometers per second, 3 body lengths per second). This skeletal muscle-based biohybrid swimmer attains speeds comparable with those of cardiac-based biohybrid robots and outperforms other muscle-based swimmers. The integration of serpentine-like structures in hybrid robotic systems allows self-stimulation processes that could lead to higher force outputs in current and future biomimetic robotic platforms.

Hero Turned Villain: Identification of Components of the Sex Pheromone of the Tomato Bug, Nesidiocoris tenuis

Nesidiocoris tenuis (Reuter) (Heteroptera: Miridae) is a tropical mirid bug used as a biocontrol agent in protected crops, including tomatoes. Although N. tenuis predates important insect pests, especially whitefly, it also causes damage by feeding on tomato plants when prey populations decline, resulting in significant economic losses for growers. The pest is now established in some all-year-round tomato crops in Europe and control measures involve the application of pesticides which are incompatible with current IPM programs. As part of future IPM strategies, the pheromone of N. tenuis was investigated. Volatile collections were made from groups and individuals of mated and unmated, females and males. In analyses of these collections by gas chromatography coupled with electroantennographic (EAG) recording from antennae of male bugs, two EAG-active components were detected and identified as 1-octanol and octyl hexanoate. Unlike other mirids, both male and female N. tenuis produced the two compounds, before and after mating, and both sexes gave EAG responses to both compounds. Furthermore, only octyl hexanoate was detected in whole body solvent washes from both sexes. These compounds are not related to the derivatives of 3-hydroxybutyrate esters found as pheromone components in other members of the Bryocrinae sub-family, and the latter could not be detected in volatiles from N. tenuis and did not elicit EAG responses. Nevertheless, experiments carried out in commercial glasshouses showed that traps baited with a blend of the synthetic pheromone components caught essentially only male N. tenuis, and significantly more than traps baited with octyl hexanoate alone. The latter caught significantly more N. tenuis than unbaited traps which generally caught very few bugs. Traps at plant height caught more N. tenuis males than traps 1 m above or at the base of the plants. The trap catches provided an indication of population levels of N. tenuis and were greatly reduced following an application of insecticide.