2-Hydroxy-3-(p-nitrobenzenesulfonylamino)propylammonium p-nitrobenzenesulfonate

The title compound, [NO2C6H4SO2NHCH2CHOHCH2NH3]+- [p-NO2C6H4SO3]ÿ or C9H14N3O5S+ C6H4NO5Sÿ, was isolated from the reaction between 1,3-diamino-2-hydroxypropane and p-nitrobenzenesulfonyl chloride in CH2Cl2. The fairly extensive hydrogen-bond system involving all `active' H atoms links the ions in the crystal into layers normal to the b axis.published_or_final_versio

In vivo demonstration of enhancing gas-filled microbubble magnetic susceptibility with iron oxide nanoparticles

Short TE & Susceptibility MRI: No. 698Gas-filled microbubbles have been shown as an MR susceptibility contrast agent; however, microbubble susceptibility effect is relatively weak when compared with other contrast agents. Studies have indicated that, by embedding magnetic nanoparticles, the magnetic susceptibility of the shell can be increased, thus enhancing the microbubble susceptibility effect. In this study, we further demonstrated the synergistic effect of gas core with iron oxide nanoparticles in achieving the overall microbubble susceptibility effect and characterized in vivo enhancements of microbubble susceptibility effects by entrapping iron oxide nanoparticles at 7 T, leading to the practical use of microbubbles as an intravascular MRI contrast agent.postprin

Metabolite profiling of mild hypothermia by 1H-MRS

Posters - MRS of Animal Brain: No. 4525Hypothermia has a profound effect on the protection of brain. However, its exact mechanisms remain to be elucidated. Hypothermia induces changes in brain metabolites. 1H-MRS can detect changes in metabolites and hence help us to have a better understanding of hypothermia. Our data shows changes in several metabolites in the cortex and thalamus. These metabolites are associated with cascade of events that lead to neuroprotection and thermoregulation, which are similar to ex vivo and microdialysis findings. This real time and site specific monitor of metabolites at 7T gives insight into how hypothermia protects the brain from various insults.postprin

Taurine change in visual cortex of neonatal monocular enucleated rat: a proton MRS study

Posters - MRS of Animal Brain: 4530Neonatal monocular enucleation has been used to study developmental mechanisms underlying visual perception and the cross-modal changes in the central nervous system caused by early loss of the visual input. In this study, we demonstrated that alteration in the metabolism of taurine in visual cortex accompanied with neonatal monocular enucleation could be monitored using 1H MRS at 7 T. The change in taurine signal with respect to creatine signal may possibly due to the increased taurine signal in the right control visual cortex, likely caused by the plasticity resulted from recruitment of resources to the remaining left eye for adaptation.postprin

Diffusion-weighted balanced SSFP (DW-bSSFP): a new approach to diffusion tensor imaging

Posters - Diffusion MRI: No. 4003Although DW-EPI offers high acquisition speed, it generally suffers from low spatial resolution and geometric distortion. SSFP is a possible alternative to perform diffusion imaging with higher resolution and with no distortion artifacts that is inherent in EPI. In this study, we modified the balanced SSFP sequence by adding a pair of bipolar diffusion sensitizing gradients. The diffusion effect in bSSFP sequence with a pair of bipolar diffusion gradients was formulated and DW-bSSFP experiment was performed on in vivo rat brain at 7T.postprin

Evaluating Students' Perception of a Three-Dimensional Virtual World Learning Environment

Three-dimensional virtual environments have gained wide popularity due to improvement in graphic rendering technology and networking infrastructure. Many education institutions have been trying to leverage the potential of 3D virtual environments in their application in education. In this research, we aim to evaluate the students’ perception of virtual environments in teaching and learning activities. We set up a virtual classroom, where a short presentation was delivered to students through virtual projectors in Second Life, the most widely adopted 3D virtual environment. The students filled in a questionnaire after the class. We found that the students gave a statistically higher evaluation to 3D virtual environments in terms of satisfaction and enjoyment, while comparable scores between 3D and traditional learning environment in terms of concentration, perceived usefulness, and learning and understanding were obtained. Our results show that virtual learning environment is of great potential in e-learning. Some recommendations in using the virtual environment for learning activities are given.published_or_final_versio

Prognostic value of early, conventional proton magnetic resonance spectroscopy in cooled asphyxiated infants

BACKGROUND: Neonatal hypoxic-ischemic encephalopathy (HIE) commonly leads to neurodevelopmental impairment, raising the need for prognostic tools which may guide future therapies in time. Prognostic value of proton MR spectroscopy (H-MRS) between 1 and 46 days of age has been extensively studied; however, the reproducibility and generalizability of these methods are controversial in a general clinical setting. Therefore, we investigated the prognostic performance of conventional H-MRS during first 96 postnatal hours in hypothermia-treated asphyxiated neonates. METHODS: Fifty-one consecutive hypothermia-treated HIE neonates were examined by H-MRS at three echo-times (TE = 35, 144, 288 ms) between 6 and 96 h of age, depending on clinical stability. Patients were divided into favorable (n = 35) and unfavorable (n = 16) outcome groups based on psychomotor and mental developmental index (PDI and MDI, Bayley Scales of Infant Development II) scores (>/= 70 versus < 70 or death, respectively), assessed at 18-26 months of age. Associations between 36 routinely measured metabolite ratios and outcome were studied. Age-dependency of metabolite ratios in whole patient population was assessed. Prognostic performance of metabolite ratios was evaluated by Receiver Operating Characteristics (ROC) analysis. RESULTS: Three metabolite ratios showed significant difference between outcome groups after correction for multiple testing (p < 0.0014): myo-inositol (mIns)/N-acetyl-aspartate (NAA) height, mIns/creatine (Cr) height, both at TE = 35 ms, and NAA/Cr height at TE = 144 ms. Assessment of age-dependency showed that all 3 metabolite ratios (mIns/NAA, NAA/Cr and mIns/Cr) stayed constant during first 96 postnatal hours, rendering them optimal for prediction. ROC analysis revealed that mIns/NAA gives better prediction for outcome than NAA/Cr and mIns/Cr with cut-off values 0.6798 0.6274 and 0.7798, respectively, (AUC 0.9084, 0.8396 and 0.8462, respectively, p < 0.00001); mIns/NAA had the highest specificity (95.24%) and sensitivity (84.62%) for predicting outcome of neonates with HIE any time during the first 96 postnatal hours. CONCLUSIONS: Our findings suggest that during first 96 h of age even conventional H-MRS could be a useful prognostic tool in predicting the outcome of asphyxiated neonates; mIns/NAA was found to be the best and age-independent predictor

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Background: Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. // Methods: We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung's disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. // Findings: We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung's disease) from 264 hospitals (89 in high-income countries, 166 in middle-income countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in low-income countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. // Interpretation: Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between low-income, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Sequence Features and Transcriptional Stalling within Centromere DNA Promote Establishment of CENP-A Chromatin

Centromere sequences are not conserved between species, and there is compelling evidence for epigenetic regulation of centromere identity, with location being dictated by the presence of chromatin containing the histone H3 variant CENP-A. Paradoxically, in most organisms CENP-A chromatin generally occurs on particular sequences. To investigate the contribution of primary DNA sequence to establishment of CENP-A chromatin in vivo, we utilised the fission yeast Schizosaccharomyces pombe. CENP-ACnp1 chromatin is normally assembled on ∼10 kb of central domain DNA within these regional centromeres. We demonstrate that overproduction of S. pombe CENP-ACnp1 bypasses the usual requirement for adjacent heterochromatin in establishing CENP-ACnp1 chromatin, and show that central domain DNA is a preferred substrate for de novo establishment of CENP-ACnp1 chromatin. When multimerised, a 2 kb sub-region can establish CENP-ACnp1 chromatin and form functional centromeres. Randomization of the 2 kb sequence to generate a sequence that maintains AT content and predicted nucleosome positioning is unable to establish CENP-ACnp1 chromatin. These analyses indicate that central domain DNA from fission yeast centromeres contains specific information that promotes CENP-ACnp1 incorporation into chromatin. Numerous transcriptional start sites were detected on the forward and reverse strands within the functional 2 kb sub-region and active promoters were identified. RNAPII is enriched on central domain DNA in wild-type cells, but only low levels of transcripts are detected, consistent with RNAPII stalling during transcription of centromeric DNA. Cells lacking factors involved in restarting transcription-TFIIS and Ubp3-assemble CENP-ACnp1 on central domain DNA when CENP-ACnp1 is at wild-type levels, suggesting that persistent stalling of RNAPII on centromere DNA triggers chromatin remodelling events that deposit CENP-ACnp1. Thus, sequence-encoded features of centromeric DNA create an environment of pervasive low quality RNAPII transcription that is an important determinant of CENP-ACnp1 assembly. These observations emphasise roles for both genetic and epigenetic processes in centromere establishment