Generation of Nanostructures by the Aggregation of Porphyrin Derivatives with Long Alkane Chain in Mix-Solvent

Controlled aggregation of tetrakis-(4-(hexadecyl oxy)-phenyl) porphyrin and its copper(II)-complex was studied in mix-solvent system at room temperature. Structure of the aggregates was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and UV-visible spectroscopy. TEM results indicated the formation of organized nanostructures from the porphyrin derivative and its corresponding copper(II)-complex. XRD results showed that the bulk and nanostructured free porphyrin derivatives had the similar crystalline morphology. UV-visible-NIR spectroscopic data showed broad red-shifted Soret band, indicating JJ aggregation among the monomer units. Conjugate effect of lateral π-π interaction among the tetrapyrrole cores and hydrophobic interaction among the long alkane chains substituted in the peripheral phenyl rings is believed to lead to the organized nanostructures. Effect of solvent ratio on the aggregate structure is also revealed

The Immune System in Stroke

Stroke represents an unresolved challenge for both developed and developing countries and has a huge socio-economic impact. Although considerable effort has been made to limit stroke incidence and improve outcome, strategies aimed at protecting injured neurons in the brain have all failed. This failure is likely to be due to both the incompleteness of modelling the disease and its causes in experimental research, and also the lack of understanding of how systemic mechanisms lead to an acute cerebrovascular event or contribute to outcome. Inflammation has been implicated in all forms of brain injury and it is now clear that immune mechanisms profoundly influence (and are responsible for the development of) risk and causation of stroke, and the outcome following the onset of cerebral ischemia. Until very recently, systemic inflammatory mechanisms, with respect to common comorbidities in stroke, have largely been ignored in experimental studies. The main aim is therefore to understand interactions between the immune system and brain injury in order to develop novel therapeutic approaches. Recent data from clinical and experimental research clearly show that systemic inflammatory diseases -such as atherosclerosis, obesity, diabetes or infection - similar to stress and advanced age, are associated with dysregulated immune responses which can profoundly contribute to cerebrovascular inflammation and injury in the central nervous system. In this review, we summarize recent advances in the field of inflammation and stroke, focusing on the challenges of translation between pre-clinical and clinical studies, and potential anti-inflammatory/immunomodulatory therapeutic approaches

Optimizing Medium Components to Enhance High Cell Mass Production of Biotherapeutic Strain Lactobacillus reuteri DSM 20016T by Statistical Method

798-803Probiotics referred to a group of living microorganisms which highly influence the human health. A number of studies have highlighted on the bio-therapeutic potential of Lactobacillus reuteri strains, especially in treating eradication of Helicobacter pylori. Therefore, in present investigation, statistical methods were applied to optimize medium composition for high cell mass production of L. reuteri strain DSM 20016T. Most influencing medium components were screened by using Plackett-Burman and optimized using Box-Bhenken experimental design. The concentration of lactose, yeast extract and phosphate in cultivation medium has shown significant effect on the cell mass production. The highest cell mass obtained after 48h incubation was 3.96 ± 0.02 gL−1 in RSM-optimized medium compared to 1.76 ± 0.17 gL−1 in un-optimized medium

An Antagomir to MicroRNA Let7f Promotes Neuroprotection in an Ischemic Stroke Model

We previously showed that middle-aged female rats sustain a larger infarct following experimental stroke as compared to younger female rats, and paradoxically, estrogen treatment to the older group is neurotoxic. Plasma and brain insulin-like growth factor-1 (IGF-1) levels decrease with age. However, IGF-1 infusion following stroke, prevents estrogen neurotoxicity in middle-aged female rats. IGF1 is neuroprotective and well tolerated, but also has potentially undesirable side effects. We hypothesized that microRNAs (miRNAs) that target the IGF-1 signaling family for translation repression could be alternatively suppressed to promote IGF-1-like neuroprotection. Here, we report that two conserved IGF pathway regulatory microRNAs, Let7f and miR1, can be inhibited to mimic and even extend the neuroprotection afforded by IGF-1. Anti-mir1 treatment, as late as 4 hours following ischemia, significantly reduced cortical infarct volume in adult female rats, while anti-Let7 robustly reduced both cortical and striatal infarcts, and preserved sensorimotor function and interhemispheric neural integration. No neuroprotection was observed in animals treated with a brain specific miRNA unrelated to IGF-1 (anti-miR124). Remarkably, anti-Let7f was only effective in intact females but not males or ovariectomized females indicating that the gonadal steroid environment critically modifies miRNA action. Let7f is preferentially expressed in microglia in the ischemic hemisphere and confirmed in ex vivo cultures of microglia obtained from the cortex. While IGF-1 was undetectable in microglia harvested from the non-ischemic hemisphere, IGF-1 was expressed by microglia obtained from the ischemic cortex and was further elevated by anti-Let7f treatment. Collectively these data support a novel miRNA-based therapeutic strategy for neuroprotection following stroke

A Two-Fold Authentication Mechanism for Network Security

Security is very important90 for any kind of networks. As a main communication mode, the security mechanism for multicast is not only the measure to ensure secured communications, but also the precondition for other security services. Attacks are one of the biggest concerns for security professionals. Attackers usually gain access to a large number of computers by exploiting their vulnerabilities to set up attack armies. This paper presents a double way authentication mechanism which uses the functionality of Elliptical Curve Cryptography, Kerberos System and RSA algorithm. ECC algorithm utilized to encrypt the user information whereas RSA used to encrypt the secret key itself to ensure the more security in the networks.</jats:p

A Literature Survey on the Importance of Intrusion Detection System for Wireless Networks

Network security has become more important to personal computer users, organizations, and the military. With the advent of the internet, security became a major concern and the history of security allows a better understanding of the emergence of security technology. The entire field of network security is vast and in an evolutionary stage. The range of study encompasses a brief history dating back to internet’s beginnings and the current development in network security. In order to understand the research being performed today, background knowledge of the importance of security, types of attacks in the networks. This paper elaborates theliterature study on network security in various domains in the year 2013 to 2018. Finally, it summarizes the research directions by literature survey.</jats:p