Engineering modular and orthogonal genetic logic gates for robust digital-like synthetic biology

Modular and orthogonal genetic logic gates are essential for building robust biologically based digital devices to customize cell signalling in synthetic biology. Here we constructed an orthogonal AND gate in Escherichia coli using a novel hetero-regulation module from Pseudomonas syringae. The device comprises two co-activating genes hrpR and hrpS controlled by separate promoter inputs, and a σ54-dependent hrpL promoter driving the output. The hrpL promoter is activated only when both genes are expressed, generating digital-like AND integration behaviour. The AND gate is demonstrated to be modular by applying new regulated promoters to the inputs, and connecting the output to a NOT gate module to produce a combinatorial NAND gate. The circuits were assembled using a parts-based engineering approach of quantitative characterization, modelling, followed by construction and testing. The results show that new genetic logic devices can be engineered predictably from novel native orthogonal biological control elements using quantitatively in-context characterized parts

Prediction of Cellular Burden with Host--Circuit Models

Heterologous gene expression draws resources from host cells. These resources include vital components to sustain growth and replication, and the resulting cellular burden is a widely recognised bottleneck in the design of robust circuits. In this tutorial we discuss the use of computational models that integrate gene circuits and the physiology of host cells. Through various use cases, we illustrate the power of host-circuit models to predict the impact of design parameters on both burden and circuit functionality. Our approach relies on a new generation of computational models for microbial growth that can flexibly accommodate resource bottlenecks encountered in gene circuit design. Adoption of this modelling paradigm can facilitate fast and robust design cycles in synthetic biology

A comprehensive review on monitoring and purification of water through tunable 2D nanomaterials

Abstract Instead of typical household trash, the heavy metal complexes, organic chemicals, and other poisons produced by huge enterprises threaten water systems across the world. In order to protect our drinking water from pollution, we must keep a close eye on the situation. Nanotechnology, specifically two-dimensional (2D) nanomaterials, is used in certain wastewater treatment systems. Graphene, g-C3N4, MoS2, and MXene are just a few examples of emerging 2D nanomaterials that exhibit an extraordinary ratio of surface (m3), providing material consumption, time consumption, and treatment technique for cleaning and observing water. In this post, we'll talk about the ways in which 2D nanomaterials may be tuned to perform certain functions, namely how they can be used for water management. The following is a quick overview of nanostructured materials and its possible use in water management: Also discussed in length are the applications of 2D nanomaterials in water purification, including pollutant adsorption, filtration, disinfection, and photocatalysis. Fluorescence sensors, colorimetric, electrochemical, and field-effect transistors are only some of the devices being studied for their potential use in monitoring water quality using 2D nanomaterials. Utilizing 2D content has its benefits and pitfalls when used to water management. New developments in this fast-expanding business will boost water treatment quality and accessibility in response to rising awareness of the need of clean, fresh water among future generations

Massive Orbital Myiasis Caused by Sarcophaga argyrostoma Complicating Eyelid Malignancy

Purpose. To report a case of massive orbital myiasis caused by the larvae of Sarcophaga argyrostoma, complicating eyelid malignancy. Observations. A 98-year-old man first presented to our clinic noted to have a fast-growing lesion on his right upper and lower eyelids. Squamous cell carcinoma of the eyelids was highly suspected, and surgical excision was advised, but the patient refused any surgical or nonsurgical intervention. For the next eight months, the patient’s family members continued to observe a high rate of tumor growth accompanied by deterioration of the general condition. During this whole period, the patient rejected admission to the hospital and was observed by nursing home staff. He was admitted to the emergency room in cachexic, unresponsive condition with fetid discharge and multiple live maggots crawling out from a large necrotic mass over the right orbit. On examination, no eyelids, eyeball, or other ocular tissue could be seen, while an extension of necrotic mass to forehead and midcheek was noted. Manual removal of larvae was performed. The patient passed away eight hours after his admission and larval removal. The maggots were identified as the third-instar larvae of Sarcophaga argyrostoma. Conclusions and Importance. This is the first reported case of home-acquired, massive orbital myiasis by S. argyrostoma. This case illustrates the crucial role of fly control as part of medical and home care in immobile patients. Moreover, it shows the importance of awareness by nursing home staff, paramedical, and medical personnel of possible myiasis, especially in bed-bound patients with skin malignancies and open wounds

Human Mast Cells release Oncostatin M on contact with activated T cells: possible biologic relevance

BACKGROUND: We have recently demonstrated that mast cells can be activated by heterotypic adhesion to activated T cells. OBJECTIVE: We sought to perform gene expression profiling on human mast cells activated by either IgE cross-linking or by T cells and to characterize one of the cytokines, oncostatin M (OSM). METHODS: Gene expression profiling was done by means of microarray analysis, OSM expression was validated by means of RT-PCR, and the product was measured by means of ELISA in both the LAD 2 human mast cell line and in cord blood-derived human mast cells. Immunocytochemistry was used to localize OSM in human mast cells, and its biologic activity was verified by its effect on the proliferation of human lung fibroblasts. RESULTS: OSM was expressed and released specifically on T cell-induced mast cell activation but not on IgE cross-linking. OSM was localized to the cytoplasm, and its expression was inhibited by dexamethasone and mitogen-activated protein kinase inhibitors. OSM was also found to be biologically active in inducing lung fibroblast proliferation that was partially but significantly inhibited by anti-OSM mAb. In vivo mast cells were found to express OSM in both biopsy specimens and bronchoalveolar lavage fluid from patients with sarcoidosis. CONCLUSION: The production of OSM by human mast cells might represent one link between T cell-induced mast cell activation and the development of a spectrum of structural changes in T cell-mediated inflammatory processes in which mast cells have been found to be involved