Herbicide resistance has been studied extensively in agronomic crops across North America but is rarely examined in vegetables. It is widely assumed that the limited number of registered herbicides combined with the adoption of diverse weed management strategies in most vegetable crops effectively inhibits the development of resistance. It is difficult to determine whether resistance is truly less common in vegetable crops or whether the lack of reported cases is due to the lack of resources focused on detection. This review highlights incidences of resistance that are thought to have arisen within vegetable crops. It also includes situations in which herbicide-resistant weeds were likely selected for within agronomic crops but became a problem when vegetables were grown in sequence or in adjacent fields. Occurrence of herbicide resistance can have severe consequences for vegetable growers, and resistance management plans should be adopted to limit selection pressure. This review also highlights resistance management techniques that should slow the development and spread of herbicide resistance in vegetable crops.

Tumors, trauma, and congenital defects require volume restoration of soft tissues. Tissue engineering provides an alternative source for substituting these defects. Cell encapsulation into hydrogels provides a three-dimensional microenvironment. Spheroids of cells provide close packing and increase cell-to-cell contacts resulting in differentiation. Gelatin is a natural polymer with low immunogenicity and preserved amino acid motifs for cell adhesion and proliferation. In the present study, a soft photo-crosslinked gelatin methacrylate (GelMA) hydrogel with long in vitro lifetime was synthesized. Stem cells (dental pulp derived, DPSC) and endothelial cells (umbilical cord derived, HUVEC) were formed into spheroids to induce prevascular network formation and encapsulated into GelMA (10% weight/volume). Results showed high cell viability, better gel mechanical properties, and longer HUVEC sprouting with spheroids compared to the same combination of cells. Altogether, the photo-crosslinked GelMA hydrogels with DPSC and HUVEC spheroids provided a promising tissue engineering and vascularization strategy in vitro.

America’s entrepreneurial culture is important because it promotes the search for new opportunities for innovation. Here, the author traces that culture through two industrial revolutions and focuses on the growing tension between entrepreneurship and bureaucracy inside and outside of the nation’s twentieth-century firms. Business histories are explored using categories adapted from behavioral economics. Particular attention is devoted to some of the important exceptions that throw light upon the stereotypes of the static government agency and the slow-moving industrial firm. Still, the author concludes, following World War II the economy had to be pulled out of its bureaucratic doldrums by new science- and social science-based industries that invigorated the nation’s entrepreneurial culture and promoted a wave of significant biological and digital innovations. The article concludes with a glance at the future of the bureaucratic and entrepreneurial cultures.

Chalcopyrite quantum dots (QDs) have emerged as a safe alternative to cadmium-based QDs for bio-applications. However, the research on AgInS2 chalcopyrite QDs has not been widely explored in terms of their toxicity. Herein, we report a synthesis of biocompatible AgInS2/ZnS QDs via a greener approach. The emission intensity of the as-synthesized AgInS2 core QDs was enhanced 2-fold after the ZnS shell growth. X-ray diffraction revealed the tetragonal crystal structure of QDs, and high-resolution transmission electron microscope images show that the QDs are spherical in shape and crystalline in nature. Cell viability assays conducted on different cell lines, such as HeLa, A549, and BHK-21 cells, indicated that AgInS2/ZnS QDs are least toxic at a QD concentration range of 100 µg/mL. The fluorescent microscope analysis of A549 cells incubated with AgInS2/ZnS QDs shows that the QDs were accumulated in the cell membranes. The as-synthesized AgInS2/ZnS QDs are less toxic and eco-friendly, and can be used for biolabeling.

The deliberate use of chemical, biological, radiological, and nuclear (CBRN) materials in war or terrorist attacks is perceived as a great threat globally. In the event of a release of CBRN agents, protection by means of medical countermeasures (MedCMs) could reduce health vulnerability. Nonetheless, for some diseases caused by these agents, innovative MedCMs do not exist and many of those that do might not be readily available. Inappropriate research and development funding and government procurement efforts can result in adverse economic consequences (eg, lost income, cost per loss of life, medical expenses) far exceeding the costs of strong and comprehensive preparedness initiatives. By illustrating factors of demand-side rationale for CBRN MedCMs, this article aims to strengthen integrity of policy-making associated with current demand requirements. Namely, an approach to inspire broader assessment is outlined by compiling and adapting existing economic models and concepts to characterize both soft and hard factors that influence demand-side rationale. First, the soft factor context is set by describing the impact of behavioral and political economics. Then, lessons learned from past public health funding models and associated collaborative access infrastructure are depicted to represent hard factors that can enhance the viability of MedCM preparedness evaluations.

The dynamic mechanical force transmitted through microenvironments during tissue formation and regeneration continuously impacts the mechanics of cells and thereby regulates gene and protein expression. The mechanical properties are altered during the process of stem cells differentiating into different lineages. At different stages of differentiation, stem cells display different mechanical properties in response to surrounding microenvironments, which depend on the subcellular structures, especially the cytoskeleton and nucleus. The mechanical properties of the cell nucleus affect protein folding and transport as well as the condensation of chromatin, through which the cell fate is regulated. These findings raise the question as to how cell mechanics change during differentiation. In this study, the mechanical properties of human bone marrow mesenchymal stem cells (hBMSCs) were determined during adipogenic and osteogenic differentiation by atomic force microscopy (AFM). The cytoskeletal structure and the modification of histone were investigated using laser confocal microscope and flow cytometry. The mechanical properties of cell nuclei at different stages of cell differentiation were compared. The stiffness of nuclei increased with time as osteogenesis was induced in hBMSCs. The H3K27me3 level increased during osteogenesis and adipogenesis according to flow cytometry analysis. Our results show conclusively that AFM is a facile and effective method to monitor stem cell differentiation. The measurement of cell mechanical properties by AFM improves our understanding on the connection between mechanics and stem cell fate.

With their abilities of self-renewal and pluripotency to differentiate into all three germ layers, human induced pluripotent stem cells (hiPSCs) are a promising cell source for cell-based drug and implant testing. However, the large-scale expansion and maintenance of hiPSCs requires following strict protocols. There is high demand for advanced cell culture systems capable of generating high-quality hiPSCs to meet application requirements. In this study, we probe the possibility of modifying polymeric substrates for maintaining the self-renewal and pluripotency of hiPSCs. Here, polydopamine (PDA) was employed to immobilize the Laminin 521 (LN521) onto the surface of polyethylene terephthalate (PET). An aqueous solution of dopamine with concentrations ranging from 0 to 2.0 mg/mL was applied on PET surfaces. These PDA-modified surfaces were further functionalized with LN521. Surface wettability was evaluated by measuring the water contact angle (WCA) and surface properties of the modified substrate were analyzed using an atomic force microscope (AFM). Initial hiPSC attachment (1h after seeding) and cell proliferation were evaluated by counting the total cell number. The maintenance of pluripotency was evaluated at designed time points. WCA of the PDA-LN521 surfaces gradually decreased from 62.1°±6.3° to 8.1°±2.9°. The maximum peak-to-valley height roughness (Rt) of those surfaces determined by AFM increased in a dopamine-concentration-dependent manner, ranging from 43.9±1.6 nm to 126.7±7.6 nm. The Young’s modulus of these surfaces was substantially increased from 0.98±0.36 GPa to 4.81±2.41 GPa. There was a significant enhancement (13.0±7.2% and 24.2±8.1%) of hiPSC adhesion on PDA-LN521 (dopamine concentration at 0.125 and 0.25 mg/mL). When increasing the dopamine concentration to 0.5 and 1.0 mg/mL, there was no further increase in hiPSC adhesion on PDA-LN521 surfaces. Moreover, hiPSC proliferation was remarkably enhanced on PDA-LN521 surface (dopamine solution at concentration from 0.125 to 1.0 mg/mL). Pluripotency of hiPSCs was not affected by PDA treatment. In conclusion, PDA-mediated surface modification is an effective approach for the robust expansion and maintenance of hiPSCs on polymer substrates.

A fundamental design rule that nature has developed for biological machines is the intimate correlation between motion and function. One class of biological machines is molecular motors in living cells, which directly convert chemical energy into mechanical work. They coexist in every eukaryotic cell, but differ in their types of motion, the filaments they bind to, the cargos they carry, as well as the work they perform. Such natural structures offer inspiration and blueprints for constructing DNA-assembled artificial systems, which mimic their functionality. In this article, we describe two groups of cytoskeletal motors, linear and rotary motors. We discuss how their artificial analogues can be built using DNA nanotechnology. Finally, we summarize ongoing research directions and conclude that DNA origami has a bright future ahead.

In this work, flavonoids in Polygonum cuspidatum Sieb. et Zucc. were extracted by ultrasound-assisted methodology and determined by ultraviolet–visible spectrophotometry. After that, extraction conditions were optimized by the single fact investigation, the central composite design, and response surface methodology (RSM) in turn. The results showed the optimal values of ethanol concentration, solid–liquid ratio, extraction temperature, extraction time, ultrasonic power, and number of extraction times were 60%, 1:20 (g/mL), 45 °C, 34 min; 80 W, and 5, respectively. The extraction ratio of flavonoids could be as high as 94.50%. The influence order of each factor was ultrasonic power > extraction time > extraction temperature > ethanol concentration. The results also showed that the experimental value was close to the predicted value (94.49%) of the established model by RSM, which proved that the established model was reasonable. The thermodynamic results showed that the extraction process was endothermic and could proceed spontaneously.

Nature’s optical nanomaterials are poised to form the platform for future optical devices with unprecedented functionality. The brilliant colors of many animals arise from the physical interaction of light with nanostructured, multifunctional materials. While their length scale is typically in the 100-nm range, the morphology of these structures can vary strongly. These biological nanostructures are obtained in a controlled manner, using biomaterials under ambient conditions. The formation processes nature employs use elements of both equilibrium self-assembly and far-from-equilibrium and growth processes. This renders not only the colors themselves, but also the formation processes technologically and ecologically highly relevant. Yet, for many biological nanostructured materials, little is known about the formation mechanisms—partially due to a lack of in vivo imaging methods. Here, we present the toolbox of natural multifunctional nanostructures and the current knowledge about the understanding of their far-from-equilibrium assembly processes.

Periodontitis, or conventionally “Gum Disease,” is the infection and inflammation of gingival tissue, and is currently the leading cause of tooth loss in the United States. One of the most effective treatments of periodontitis is guided bone regeneration (GBR); however, current GBR barrier membranes lack high biocompatibility and cell impermeability. The authors of this study evaluated the in vitro viability of previously synthesized Gelatin-Pluronic® F127 hybrid hydrogels as potential GBR barrier membranes through a novel three-partition test involving migration of fluorescent-dyed human dermal fibroblasts. Results showed that cells were unable to migrate across the Gelatin-Pluronic® F127 hybrid hydrogel barrier, whereas control setups with gelatin hydrogel barriers showed cell permeability. In addition, cytotoxicity tests were conducted with fibroblasts plated in both cell mediums that had been incubated while in contact hybrid gels and cell mediums suspended on the surface of hybrid gels during swelling procedures. Fluorescence cell plate readings showed similar cell viability across data from both tests, indicating that Gelatin-Pluronic® F127 hybrid hydrogels are not toxic to cells, and thus biocompatible.