Three-dimensional metal organic frameworks for atomic scale patterning

Metal organic frameworks (MOFs) belong to a sub class of coordination polymers in which metal ion nodes are connected with organic ligands to make three-dimensional framework. High porosity of MOFs makes them appealing in real-world applications, such as storage for harmful gasses, drug delivery cargo, and in recently for electronic devices. This dissertation focuses the development of a new synthetic design strategy that offers structural modifications to construct MOFs with tailored optoelectronic and magnetic properties. Combining a solvent driven self-assembly process with a solvothermal method, a series of highly crystalline hierarchical microstructures of isoreticular MOFs, having metal nodes of zinc, manganese, and iron were synthesized and their optoelectronic and magnetic properties were investigated. The synthesis method developed in this research enables tailoring the crystalline structure and its packing pattern, contributing to tailor their properties. The three isoreticular MOFs (IRMOFs) prepared using this novel synthesis method were interpenetrated IRMOF-8 (IRMOF-8A), MIL-88 and Mn-MOF. The structural composition, morphological characterization, and crystalline packing of these MOFs were confirmed. Using this novel synthetic strategy, the crystalline packing pattern and structural orientation of original IRMOF-8 were tailored, yielding its interpenetrating crystal structure with promising optoelectronic properties. Three isoreticular homologous of MIL-88 prepared in same manner by varying the organic linker length using benzene dicarboxylic acid (BDC), naphthalene dicarboxylic acid (NDC), and bi-phenyl dicarboxylic acid (BPDC) as organic linkers, show magnetic behavior below room temperature. Finally, 3D microstructures of Mn- MOF prepared by coordinating Mn+2 with NDC exhibits luminescent behavior, attributing to the ligand emission. The hierarchical structures of isoreticular MOFs developed in this research will contribute to the potential applications in optoelectronic, memory storage, and light harvesting devices, respectively

Street Food Consumption and Hygiene Issues in George Town, Penang

The era of globalization has witnessed the growing phenomenon of consumption or consumerism in parallel with socio-cultural change and improvement in economic progress. However, Penang street food poor business placement causes issue of cleanliness and food safety to emerge. This study was carried out to explore the aspects of street food consumption in the city of George Town and its relation to hygiene issues. The George Town city area was selected because it is known as a World Heritage Site by UNESCO and a gastronomic city that turn it into a popular tourist destination in Malaysia. This study focuses on hawkers’ attitude towards street food cleanliness. It also reflects the consumers’ perception on food and hygiene issues. Questionnaire instruments have been used in this study through random sampling methods. The population of the study involved 200 respondents, consisting of 100 local consumers/local tourists and 100 international tourists whom experienced consuming street foods around the city of George Town. For the hawker’s category, the researchers have collected 30 respondents to answer the questionnaires. Researchers have also used in-depth interviews with seven street food vendors/hawkers. The findings revealed that hygiene issues amongst street food operations are serious issue although there were variations in terms of findings for local and international consumers. Thus, the government and street food vendor/hawkers should address the issues of hygiene practices through various initiatives and measures

Expression of the phosphorylated MEK5 protein is associated with TNM staging of colorectal cancer

<p>Abstract</p> <p>Background</p> <p>Activation of MEK5 in many cancers is associated with carcinogenesis through aberrant cell proliferation. In this study, we determined the level of phosphorylated MEK5 (pMEK5) expression in human colorectal cancer (CRC) tissues and correlated it with clinicopathologic data.</p> <p>Methods</p> <p>pMEK5 expression was examined by immunohistochemistry in a tissue microarray (TMA) containing 335 clinicopathologic characterized CRC cases and 80 cases of nontumor colorectal tissues. pMEK5 expression of 19 cases of primary CRC lesions and paired with normal mucosa was examined by Western blotting. The relationship between pMEK5 expression in CRC and clinicopathologic parameters, and the association of pMEK5 expression with CRC survival were analyzed respectively.</p> <p>Results</p> <p>pMEK5 expression was significantly higher in CRC tissues (185 out of 335, 55.2%) than in normal tissues (6 out of 80, 7.5%; <it>P </it>< 0.001). Western blotting demonstrated that pMEK5 expression was upregulated in 12 of 19 CRC tissues (62.1%) compared to the corresponding adjacent nontumor colorectal tissues. Overexpression of pMEK5 in CRC tissues was significantly correlated to the depth of invasion (<it>P </it>= 0.001), lymph node metastasis (<it>P </it>< 0.001), distant metastasis (<it>P </it>< 0.001) and high preoperative CEA level (<it>P </it>< 0.001). Consistently, the pMEK5 level in CRC tissues was increased following stage progression of the disease (<it>P </it>< 0.001). Analysis of the survival curves showed a significantly worse 5-year disease-free (<it>P </it>= 0.002) and 5-year overall survival rate (<it>P </it>< 0.001) for patients whose tumors overexpressed pMEK5. However, in multivariate analysis, pMEK5 was not an independent prognostic factor for CRC (DFS: <it>P </it>= 0.139; OS: <it>P </it>= 0.071).</p> <p>Conclusions</p> <p>pMEK5 expression is correlated with the staging of CRC and its expression might be helpful to the TNM staging system of CRC.</p

Causes and differentials of childhood mortality in Iraq

<p>Abstract</p> <p>Background</p> <p>Limited information is available in Iraq regarding the causes of under-five mortality. The vital registration system is deficient in its coverage, particularly from rural areas where access to health services is limited and most deaths occur at home, i.e. outside the health system, and hence the cause of death goes unreported. Knowledge of patterns and trends in causes of under-five mortality is essential for decision-makers in assessing programmatic needs, prioritizing interventions, and monitoring progress. The aim of this study was to identify causes of under-five children deaths using a simplified verbal autopsy questionnaire.</p> <p>The objective was to define the leading symptoms and cause of death among Iraqi children from all regions of Iraq during 1994–1999.</p> <p>Methods</p> <p>To determine the cause structure of child deaths, a simplified verbal autopsy questionnaire was used in interviews conducted in the Iraqi Child & Maternal Mortality Survey (ICMMS) 1999 national sample. All the mothers/caregivers of the deceased children were asked open-ended questions about the symptoms within the two weeks preceding death; they could mention more than one symptom.</p> <p>Results</p> <p>The leading cause of death among under-five children was found to be childhood illnesses in 81.2%, followed by sudden death in 8.9% and accidents in 3.3%. Among under-five children dying of illnesses, cough and difficulty in breathing were the main symptoms preceding death in 34.0%, followed by diarrhea in 24.4%. Among neonates the leading cause was cough/and or difficulty in breathing in 42.3%, followed by sudden death in 11.9%, congenital abnormalities in 10.3% and prematurity in 10.2%. Diarrhea was the leading cause of death among infants in 49.8%, followed by cough and/or difficulty in breathing in 26.6%. Among children 12–59 months diarrhea was the leading cause of death in 43.4%, followed by accidents, injuries, and poisoning in 19.3%, then cough/difficulty in breathing in 14.8%.</p> <p>Conclusion</p> <p>In Iraq Under-five child mortality is one of the highest in the Middle East region; deaths during the neonatal period accounted for more than half of under-five children deaths highlighting an urgent need to introduce health interventions to improve essential neonatal care. Priority needs to be given to the prevention, early and effective treatment of neonatal conditions, diarrheal diseases, acute respiratory infections, and accidents. This study points to the need for further standardized assessments of under-5 mortality in Iraq.</p

Structural and Functional Analysis of Laninamivir and its Octanoate Prodrug Reveals Group Specific Mechanisms for Influenza NA Inhibition

The 2009 H1N1 influenza pandemic (pH1N1) led to record sales of neuraminidase (NA) inhibitors, which has contributed significantly to the recent increase in oseltamivir-resistant viruses. Therefore, development and careful evaluation of novel NA inhibitors is of great interest. Recently, a highly potent NA inhibitor, laninamivir, has been approved for use in Japan. Laninamivir is effective using a single inhaled dose via its octanoate prodrug (CS-8958) and has been demonstrated to be effective against oseltamivir-resistant NA in vitro. However, effectiveness of laninamivir octanoate prodrug against oseltamivir-resistant influenza infection in adults has not been demonstrated. NA is classified into 2 groups based upon phylogenetic analysis and it is becoming clear that each group has some distinct structural features. Recently, we found that pH1N1 N1 NA (p09N1) is an atypical group 1 NA with some group 2-like features in its active site (lack of a 150-cavity). Furthermore, it has been reported that certain oseltamivir-resistant substitutions in the NA active site are group 1 specific. In order to comprehensively evaluate the effectiveness of laninamivir, we utilized recombinant N5 (typical group 1), p09N1 (atypical group 1) and N2 from the 1957 pandemic H2N2 (p57N2) (typical group 2) to carry out in vitro inhibition assays. We found that laninamivir and its octanoate prodrug display group specific preferences to different influenza NAs and provide the structural basis of their specific action based upon their novel complex crystal structures. Our results indicate that laninamivir and zanamivir are more effective against group 1 NA with a 150-cavity than group 2 NA with no 150-cavity. Furthermore, we have found that the laninamivir octanoate prodrug has a unique binding mode in p09N1 that is different from that of group 2 p57N2, but with some similarities to NA-oseltamivir binding, which provides additional insight into group specific differences of oseltamivir binding and resistance

Antiviral activity and possible mechanisms of action of pentagalloylglucose (PGG) against influenza A virus.

Influenza A virus (IAV) infection is a major public health threat leading to significant morbidity and mortality. The emergence of drug-resistant virus strains highlights the urgent need to develop novel antiviral drugs with alternative modes of action. Pentagalloylglucose (PGG), a naturally occurring polyphenolic compound, possesses a broad spectrum of biological activities. In this study, we found that PGG has anti-influenza-virus activity, and investigated its possible mechanism(s) of action in vitro. Both pre-incubation of virus prior to infection and post-exposure of infected cells with PGG significantly inhibited virus yields. Influenza-virus-induced hemagglutination of chicken red blood cells was inhibited by PGG treatment, suggesting that PGG can inhibit IAV infection by interacting with the viral hemagglutinin. PGG did not affect viral protein synthesis or nuclear transport of viral nucleoprotein (NP) but greatly reduced plasma membrane accumulation of NP protein at the late stage of the replication cycle. Furthermore, PGG significantly reduced virus budding and progeny virus release from infected cells. This study revealed for the first time that PGG can inhibit IAV replication with a dual mode of action and offers new insights into its underlying mechanisms of antiviral action

Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe

Serum BDNF Concentrations Show Strong Seasonal Variation and Correlations with the Amount of Ambient Sunlight

Contains fulltext : 109494.pdf (publisher's version ) (Open Access)Earlier findings show seasonality in processes and behaviors such as brain plasticity and depression that in part are regulated by Brain-Derived Neurotrophic Factor (BDNF). Based on this we investigated seasonal variation in serum BDNF concentrations in 2,851 persons who took part in the Netherlands Study of Depression and Anxiety (NESDA). Analyses by month of sampling (monthly n's >196) showed pronounced seasonal variation in serum BDNF concentrations (P<.0001) with increasing concentrations in the spring-summer period (standardized regression weight (ss) = 0.19, P<.0001) and decreasing concentrations in the autumn-winter period (ss = -0.17, P<.0001). Effect sizes [Cohen's d] ranged from 0.27 to 0.66 for monthly significant differences. We found similar seasonal variation for both sexes and for persons with a DSM-IV depression diagnosis and healthy control subjects. In explorative analyses we found that the number of sunshine hours (a major trigger to entrain seasonality) in the week of blood withdrawal and the 10 weeks prior to this event positively correlated with serum BDNF concentrations (Pearson's correlation coefficients ranged: 0.05-0.18) and this could partly explain the observed monthly variation. These results provide strong evidence that serum BDNF concentrations systematically vary over the year. This finding is important for our understanding of those factors that regulate BDNF expression and may provide novel avenues to understand seasonal dependent changes in behavior and illness such as depression. Finally, the findings reported here should be taken into account when designing and interpreting studies on BDNF