Crystal engineering of molecular to nonmolecular metal malonates in the presence of piperazine: Role of metal ions in tuning architectures

Growth of transition metal malonate (mal) based solids from aqueous solution is investigated in the presence of piperazine (pip). Reaction under ambient conditions favored the growth of [{M(mal)2(H2O)2}{H2pip}] (M: Ni, 1; M: Co, 2), [{Cu(mal)2(H2O)2}{H2pip}].2H2O (3), and, [Zn(mal)(pip)(H2O)] (4). While 1-3 are molecular solids, 4 is a 2-D coordination polymer. In the case of cobalt, higher acidic condition favored the formation of a molecular organic-inorganic salt, [(H2pip){CoCl4}] (5). The same reaction under a different crystallization condition, i.e., lesser polar solvent and slightly higher temperature (solvothermal) led to a 2-D coordination polymer [{Co(mal)(H2O)(Hpip)}]Cl (6). A retrosynthesis approach has been employed to interpret the crystallization reaction and compare the supramolecular reactivity of aggregating metal tectons in engineering the molecules to form either a molecular solid or coordination polymer

Informational interviews help undergraduate students at the mid-point of non-vocational STEM degrees confirm their career aspirations

Higher education institutions are expected to produce career-ready graduates who are equipped for the challenges of the 21st century. Employability experts argue that this can be achieved by integrating career development learning (CDL) into the curriculum. The informational interview helps students learn more about a career by interviewing a professional working in a field of interest, and helps students to make decisions regarding their career plans. The aims of the study were to determine students’: 1) preferred career paths and career identity at the midpoint of their non-vocational degree; 2) experiences and perceptions of an informational interview module. An informational interview module was embedded into a second-year human biosciences subject taken by students in undergraduate non-specialist health-related STEM degrees. Students indicated their preferred career, learned about informational interviews, and conducted an interview with a professional working in the field they wished to enter. After the interview, students completed reflection activities, responding to open-ended and Likert-scale questions. 91 student reflections were analysed to determine students’ career identity, and their experiences and perceptions of the module. Descriptive statistical analysis was conducted on Likert-scale answers and inductive thematic analysis was conducted on open-ended answers. Students’ career preferences were wide-ranging, with allied health the most popular. Career identity was reasonably well established in this cohort. The student experience was overall positive, and students’ thought the module was useful in supporting their career planning and career development. In conclusion, an informational interview assignment is an effective career development tool for human biosciences students

ZnO and MgZnO Nanocrystalline Flexible Films: Optical and Material Properties

An emerging material for flexible UV applications is MgxZn1−xO which is capable of tunable bandgap and luminescence in the UV range of ~3.4 eV–7.4 eV depending on the composition x. Studies on the optical and material characteristics of ZnO and Mg0.3Zn0.7O nanocrystalline flexible films are presented. The analysis indicates that the ZnO and Mg0.3Zn0.7O have bandgaps of 3.34 eV and 4.02 eV, respectively. The photoluminescence (PL) of the ZnO film was found to exhibit a structural defect-related emission at ~3.316 eV inherent to the nanocrystalline morphology. The PL of the Mg0.3Zn0.7O film exhibits two broad peaks at 3.38 eV and at 3.95 eV that are discussed in terms of the solubility limit of the ZnO-MgO alloy system. Additionally, external deformation of the film did not have a significant impact on its properties as indicated by the Raman LO-mode behavior, making these films attractive for UV flexible applications

Effects of anti-inflammatory bioactives on diabetes-induced changes in cognition-related gene expression in the hippocampus

Research Doctorate - Doctor of Philosophy (PhD)Diabetes is a metabolic disorder that leads to other health complications over a period of time and is the cause for considerable morbidity and mortality world-wide. The complications of diabetes in the peripheral tissues are well characterized including coronary heart disease, retinal degeneration, renal disorders, and also micro and macro vascular complications. Over the last few decades much emphasis has been placed on the complications of diabetes that occur in the central nervous system (CNS). One such neuropathology due to diabetes in CNS is cognitive impairment. The hippocampus, the limbic structure, is involved in higher brain functions and appears to be particularly vulnerable to diabetes. This thesis presents studies conducted on hippocampal gene expression profiles under diabetic and non-diabetic conditions which would give us a clear understanding of the molecular mechanisms that underpin cognitive impairment due to diabetes. To understand gene expression profile in the hippocampus region of the brain, microarray technology was used and the genes of interest were further confirmed by quantitative real-time polymerase chain reaction (RT-qPCR). Investigation of two dietary interventions, fish oil rich in docosahexaenoic acid (DHA) and resveratrol (RES) were also carried out to examine the mechanism by which these naturally occurring compounds may act to provide neuronal protection thereby aiding in the prevention and delay of cognitive impairment due to diabetes. The first research chapter (Chapter 3), presents a study on the comparison of gene expression profile in the hippocampus of a streptozotocin (STZ) induced diabetic mice and a vehicle treated control animals. Here it is demonstrated that diabetes causes significant alterations in the genes that plays a crucial role in synaptic function and plasticity and also for neurogenesis, both of which are required for normal cognitive functions. Six weeks after diabetes was established in these mice, a number of genes had altered expression including genes involved in epigenetic regulation, and this included histone deacetylase (Hdac) 4, 9 and 11. Interestingly Hdac 4 and 9 are abundantly present in the hippocampus and are required for hippocampal dependent learning, memory and synaptic plasticity. Glycogen synthase kinase beta (Gsk3β) which has been shown to have a crucial role in metabolic and neurodevelopmental functions and considered to be an important regulator of synaptic functions, also exhibited significant decrease in the STZ induced diabetic mice as opposed to the buffer treated control group. The marked decrease of these genes that are crucial for higher functions in the hippocampus underscores the impact of uncontrolled diabetes on the hippocampus. Furthermore genes that have been linked to neurological disorder and cognitive dysfunction such as apolipoprotien E (ApoE) showed increased expression in diabetic mice as opposed to the non- diabetic control group. These findings implicate the abnormal transcription of genes which could disrupt normal cognitive functions in the hippocampus and also underscores epigenetic mechanisms involved in disease conditions like diabetes. The second research chapter (Chapter 4) explores whether a dietary intervention had any effect on the hippocampal gene expression profile in non- diabetic mice. A vast body of evidence indicates that DHA and RES have a beneficial effect on cognitive functions. In this chapter, we also sought to examine the effects of DHA and RES individually or in combination on hippocampal gene expression. Here it is demonstrated that both DHA and RES modulate inflammatory signals; neurotrophin signalling and neurogenesis related mechanisms. In the combined intervention group, additional genes such as Sod1, Sod2, Hmox1 and ApoE in pathways such as antioxidants and apo-lipoprotein pathways were also implicated. This study provides insight into the effects of dietary modification that modulate gene expressions favourably for normal cognitive functions and prevent or delay neurodegeneration in disease conditions such as diabetes or those seen in aging. The third research chapter (chapter 5), presents a study aimed at exploring the effects of a RES dietary supplementation on hippocampal gene expression profile in STZ induced diabetic mice as opposed to a non-supplemented diabetic group. Here it is demonstrated that dietary supplementation with RES significantly increases the expression of histone deacetylase 4(Hdac4), superoxide dismutase 2(Sod2), heme oxygease 1(Hmox1), and decreases the expression of pro-inflammatory interleukin22 (Il22), interleukin 15 (Il15), suppressor of cytokine signalling 2(Socs2), suppressor of cytokine signalling 5 (Socs5) exhibiting that RES has diverse biological properties, in addition to its already established properties as a potent antioxidant and anti-inflammatory compound. The fourth research chapter (chapter 6), presents a study aimed at exploring the effects of dietary supplementation with DHA on hippocampal gene expression profile in STZ induced diabetic mice. Here we demonstrated that dietary intervention of DHA had anti-inflammatory effects as opposed to the non- supplemented diabetic group. Dietary supplementation of DHA also exhibited an increased expression of genes that are involved in neuronal protection and survival. DHA supplementation showed an increase in insulin like growth factor II (IgfII) and also sirtuin deacetylase 1(Sirt1) expression. A decrease in pro-inflammatory tumor necrosis factor- alpha (Tnf-α), interleukin 6 (Il6) and apolipoprotien E (ApoE) was seen in DHA supplemented diabetic mice as opposed to non- supplemented diabetic mice group. Together these studies have investigated the molecular mechanism that underpins cognitive dysfunction that are apparent in diabetes and have also explored the effect of nutritional intervention with RES and DHA in the hippocampus of STZ induced diabetic and non-diabetic mice. Of the many therapeutic approaches nutritional intervention appears promising and evidence from the present study reinforces the potential of nutritional intervention to modulate the complex aberrant metabolic insults that initiate and underpin cognitive impairments due to diabetes

Dietary supplementation with resveratrol and/or docosahexaenoic acid alters hippocampal gene expression in adult C57Bl/6 mice

The hippocampus is an important brain structure for multiple cognitive functions, including memory formation. It is particularly sensitive to insults, such as stress, ischemia, and aging; all of these can affect hippocampal and therefore cognitive function. To understand the potential of diet for the preservation of hippocampal function, we investigated the effects of dietary supplementation with resveratrol (RES) or docosahexaenoic acid (DHA), or their combination, on hippocampal gene expression in adult C57BL/6 mice. Animals in the supplemented group received either 50 mg/kg/day of RES or DHA, while the combination group received 50 mg/kg/day of each supplement. Dietary supplements were mixed with the AIN93G diet, and supplementation lasted 6 weeks. The control group received AIN93G diet alone for the same period. At the end of the experiment, the hippocampi were processed for genome-wide gene expression and pathway analyses. Most of the genes that were significantly altered were associated with inflammatory responses as determined by pathway analysis. RES-supplemented animals showed decreased expression of IL-6 ( P=001), MAPKapk2 ( P=015), and increased expression for PI3. KR2 ( P=034) and Wnt7a ( P=004) expression. DHA-supplemented animals showed a decreased IL-6 ( P=003) and an increased Wnt7a ( P=003) expression. Animals on the combination diet showed a decreased IL-6 ( P=005) and Apolipoprotien E ( ApoE) ( P=035) expression. Our findings demonstrate that hippocampal gene expression is significantly altered by all three dietary supplementation regimes. Moreover, our analysis indicates that RES and DHA likely exert their beneficial effects through antiinflammatory mechanisms

Crystal engineering of molecular to nonmolecular metal malonates in presence of piperazine: Role of metal ions in tuning architectures

1081-1090Growth of transition metal malonate (mal) based solids from aqueous solution is investigated in the presence of piperazine (pip). Reaction under ambient conditions favored the growth of [{M(mal)2(H2O)2}{H2pip}] (M: Ni, 1; M: Co, 2), [{Cu(mal)2(H2O)2}{H2pip}].2H2O (3), and, [Zn(mal)(pip)(H2O)] (4). While 1-3 are molecular solids, 4 is a 2-D coordination polymer. In the case of cobalt, higher acidic condition favored the formation of a molecular organic-inorganic salt, [(H2pip){CoCl4}] (5). The same reaction under a different crystallization condition, i.e., lesser polar solvent and slightly higher temperature (solvothermal) led to a 2-D coordination polymer [{Co(mal)(H2O)(Hpip)}]Cl (6). A retrosynthesis approach has been employed to interpret the crystallization reaction and compare the supramolecular reactivity of aggregating metal tectons in engineering the molecules to form either a molecular solid or coordination polymer

Effects of dietary supplementation with docosahexaenoic acid (DHA) on hippocampal gene expression in streptozotocin induced diabetic C57Bl/6 mice

A body of evidence has accumulated indicating diabetes is associated with cognitive impairments. Effective strategies are therefore needed that will delay or prevent the onset of these diabetes-related deficits. In this regard, dietary modification with the naturally occurring compound, docosahexaenoic acid (DHA), holds significant promise as it has been shown to have anti-inflammatory, anti-oxidant, and anti-apoptotic properties. The hippocampus, a limbic structure involved in cognitive functions such as memory formation, is particularly vulnerable to the neurotoxic effects related to diabetes, and we have previously shown that streptozotocin-induced diabetes alters hippocampal gene expression, including genes involved in synaptic plasticity and neurogenesis. In the present study, we explored the effects of dietary supplementation with DHA on hippocampal gene expression in C57Bl/6 diabetic mice. Diabetes was established using streptozotocin (STZ) and once stable, the dietary intervention group received AIN93G diet supplemented with DHA (50 mg/kg/day) for 6 weeks. Microarray based genome-wide expression analysis was carried out on the hippocampus of DHA supplemented diabetic mice and confirmed by real time polymerase chain reaction (RT-qPCR). Genome-wide analysis identified 353 differentially expressed genes compared to non-supplemented diabetic mice. For example, six weeks of dietary DHA supplementation resulted in increased hippocampal expression of Igf II and Sirt1 and decreased expression of Tnf-a, Il6, Mapkapk2 and ApoE, compared to non-supplemented diabetic mice. Overall, DHA supplementation appears to alter hippocampal gene expression in a way that is consistent with it being neuroprotective in the context of the metabolic and inflammatory insults associated with diabetes