Label-free nanometer-resolution imaging of biological architectures through surface enhanced raman scattering

Label free imaging of the chemical environment of biological specimens would readily bridge the supramolecular and the cellular scales, if a chemical fingerprint technique such as Raman scattering can be coupled with super resolution imaging. We demonstrate the possibility of label-free super-resolution Raman imaging, by applying stochastic reconstruction to temporal fluctuations of the surface enhanced Raman scattering (SERS) signal which originate from biomolecular layers on large-area plasmonic surfaces with a high and uniform hot-spot density (>1011/cm2, 20 to 35 nm spacing). A resolution of 20 nm is demonstrated in reconstructed images of self-assembled peptide network and fibrilated lamellipodia of cardiomyocytes. Blink rate density is observed to be proportional to the excitation intensity and at high excitation densities (>10 kW/cm2) blinking is accompanied by molecular breakdown. However, at low powers, simultaneous Raman measurements show that SERS can provide sufficient blink rates required for image reconstruction without completely damaging the chemical structure

Label-Free Nanometer-Resolution Imaging of Biological Architectures through Surface Enhanced Raman Scattering

Label free imaging of the chemical environment of biological specimens would readily bridge the supramolecular and the cellular scales, if a chemical fingerprint technique such as Raman scattering can be coupled with super resolution imaging. We demonst

Anisotropic nanomaterials: structure, growth, assembly, and functions

Comprehensive knowledge over the shape of nanomaterials is a critical factor in designing devices with desired functions. Due to this reason, systematic efforts have been made to synthesize materials of diverse shape in the nanoscale regime. Anisotropic nanomaterials are a class of materials in which their properties are direction-dependent and more than one structural parameter is needed to describe them. Their unique and fine-tuned physical and chemical properties make them ideal candidates for devising new applications. In addition, the assembly of ordered one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) arrays of anisotropic nanoparticles brings novel properties into the resulting system, which would be entirely different from the properties of individual nanoparticles. This review presents an overview of current research in the area of anisotropic nanomaterials in general and noble metal nanoparticles in particular. We begin with an introduction to the advancements in this area followed by general aspects of the growth of anisotropic nanoparticles. Then we describe several important synthetic protocols for making anisotropic nanomaterials, followed by a summary of their assemblies, and conclude with major applications

From gut dysbiosis to altered brain function and mental illness: mechanisms and pathways

The human body hosts an enormous abundance and diversity of microbes, which perform a range of essential and beneficial functions. Our appreciation of the importance of these microbial communities to many aspects of human physiology has grown dramatically in recent years. We know, for example, that animals raised in a germ-free environment exhibit substantially altered immune and metabolic function, while the disruption of commensal microbiota in humans is associated with the development of a growing number of diseases. Evidence is now emerging that, through interactions with the gut-brain axis, the bidirectional communication system between the central nervous system and the gastrointestinal tract, the gut microbiome can also influence neural development, cognition and behaviour, with recent evidence that changes in behaviour alter gut microbiota composition, while modifications of the microbiome can induce depressive-like behaviours. Although an association between enteropathy and certain psychiatric conditions has long been recognized, it now appears that gut microbes represent direct mediators of psychopathology. Here, we examine roles of gut microbiome in shaping brain development and neurological function, and the mechanisms by which it can contribute to mental illness. Further, we discuss how the insight provided by this new and exciting field of research can inform care and provide a basis for the design of novel, microbiota-targeted, therapies.GB Rogers, DJ Keating, RL Young, M-L Wong, J Licinio, and S Wesseling

Microbiome to Brain:Unravelling the Multidirectional Axes of Communication

The gut microbiome plays a crucial role in host physiology. Disruption of its community structure and function can have wide-ranging effects making it critical to understand exactly how the interactive dialogue between the host and its microbiota is regulated to maintain homeostasis. An array of multidirectional signalling molecules is clearly involved in the host-microbiome communication. This interactive signalling not only impacts the gastrointestinal tract, where the majority of microbiota resides, but also extends to affect other host systems including the brain and liver as well as the microbiome itself. Understanding the mechanistic principles of this inter-kingdom signalling is fundamental to unravelling how our supraorganism function to maintain wellbeing, subsequently opening up new avenues for microbiome manipulation to favour desirable mental health outcome

The Effect of Fracture Pattern of Anterior Teeth on Fracture Strength of Silorane- Based and Nanohybrid Composite Restorations

Statement of problem: One of the most important concerns in choosing a treatment plan for a fractured anterior teeth is their fracture pattern. Selecting the best restorative material is crucial in restoration of them. Objective(s): The present study was aimed to evaluate the effects of fracture pattern and the composite type on the fracture strength of frac-tured anterior maxillary teeth. Materials and Methods: 40 sound maxillary anterior teeth were randomly divided into four groups of ten teeth (H1, H2, O1, and O2). In H1 and H2, the incisal edges were cut horizontally by 3mm below the incisal edge and in O1 and O2 the incisal edges were cut obliquely from the middle of incisal edge to 6mm below the incisal edge on the proximal side. A nanohybrid composite (Z350) was used for restoring the samples of H1 and O1 whilst a silorane-based composite (P90) was used in H2 and O2. Fracture strength was measured and the failure mode was recorded. Data were analyzed using one way analysis of variance (ANOVA) and Tamhane’s post hoc tests. The level of significance was p ˂0.05. Results: Restoration with composite resin Z350 showed a higher strength in both cutting patterns (p <0.001). Fracture strength was greater in horizontal pattern, regardless of the composite type used for restoration; however, the difference was not statistically significant for P90 (p= 0.930). Conclusions: Fracture resistance of the fractured anterior teeth restored with Z350 is higher than that achieved with P90 for both fracture pat-terns

A Case Report of a Patient with Leptospirosis

Abstract Background & aim: Leptospirosis is a zoonosis of worldwide distribution. One of the most important diseases common to man and animals. The aim of this study was to report a case of a patient with leptospirosis. Case Report: A 32 year old man from the southern tropical city of Kangan due to high fever, muscle pain, eye redness, enlarged liver and spleen voltage and the physical examination, slight yellowing of the conjunctiva was referred to Shahid Beheshti Hospital of Yasuj. Initial treatment of the patient's fever and flu-like symptoms before the test was ordered by physicians with antibiotics and patients' vital signs such as fever were controlled. After testing many different diseases and suspect cases, leptospirosis was confirmed. Conclusion: There is a risk of leptospirosis in presence of rodents in tropical vector and also the ecological conditions. When flu-like symptoms, enlarged liver and spleen, jaundice and symptoms of kidney involvement disease and failure to respond to conventional treatments exist, suspected cases of leptospirosis should not be missed and therefore better diagnostic tests should be conducted. Keywords: Leptospirosis, Animal, Febrile, Fl

Synthesis of versatile thiol-reactive polymer scaffolds via RAFT polymerization

Well-defined polymer scaffolds convertible to (multi)functional polymer structures via selective and efficient modifications potentially provide an easy, versatile, and useful approach for a wide variety of applications. Considering this, a homopolymer scaffold, poly(pyridyldisulfide ethylmethacrylate) (poly(PDSM)), having pendant groups selectively reactive with thiols, was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization. Soluble polymers with controlled molecular weights and narrow PDIs were generated efficiently. The versatility of the scaffold to generate random co- and ter-polymers combining multiple functionalities with controlled-composition was shown by separate and simultaneous conjugation of different mercapto-compounds, including a tripeptide in one-step. Conversion of water-insoluble scaffold to peptide-containing water-soluble copolymers was observed to yield nanometer-size particles with narrow polydispersity. The overall results suggest that the well-defined PDSM homopolymer scaffold generated via RAFT polymerization can be a versatile building block for generation of new structures having potential for drug delivery applications via a straightforward synthetic approach

Recombinant production, purification and characterization of vessel dilator in E. coli

Vessel dilator is a 3.9-KDa potent anticancer peptide and a valuable candidate in the treatment of conditions such as congestive heart failure and acute renal failure amongst others. Here we report the recombinant production of vessel dilator in Escherichia coli. Three different synthetic ORF's dubbed VDI, VDII and VDIII, each encoding a trimmer of the vessel dilator peptide attached to a His tag sequence at their C- terminal, were synthesized and placed in pET21c expression vectors. The highest yield, following expression in E. coli BL21 (DE3), was recorded with VDII that carried the shortest fusion partner. Subsequent to the initial capture of the fusion protein by a Ni affinity column, the vessel dilator monomers were cleaved by trypsin treatment, and further purified to at least 90% homogeneity by anion exchange chromatography. De-novo sequencing and in vivo anticancer activity tests were used to verify the peptide sequence and its biological activity, respectively. The final yield was estimated to be approximately 15 mg of the purified vessel dilator per gram wet weight of the bacterial cells