Nickel(II) Coordination Polymers Supported by Bis-pyridyl-bis-amide and Angular Dicarboxylate Ligands: Role of Ligand Flexibility in Iodine Adsorption

Reactions of N‚N’-bis(3-pyridylmethyl)oxalamide (L¹), N‚N’-bis(4-pyridylmethyl)oxalamide (L²), or N,N’-bis(3-pyridylmethyl)adipoamide) (L³) with angular dicarboxylic acids and Ni(II) salts under hydro(solvo)thermal conditions afforded a series of coordination polymers: {[Ni(L¹)(OBA)(H₂O)]·H₂O}_n (H₂OBA = 4,4-oxydibenzoic acid), 1, {[Ni(L¹)(SDA)(H₂O)₂]·H₂O·CH₃OH}_n (H₂SDA = 4,4-sulfonyldibenzoic acid), 2, {[Ni(L²)(OBA)]·C₂H₅OH}_n, 3, {[Ni(L²)(OBA)]·CH₃OH}_n, 4, {[Ni₂(L²)(SDA)₂(H₂O)₃]·5H₂O}_n, 5, {[Ni₂(L²)(SDA)₂(H₂O)₃]·H₂O·2C₂H₅OH}_n, 6, {[Ni(L³)(OBA)(H₂O)₂]·2H₂O}_n, 7, {[Ni(L³)(SDA)(H₂O)₂]·2H₂O}_n, 8, and {[Ni(L³)₀.₅(SDA)(H₂O)₂]·0.5C₂H₅OH}_n, 9, which have been structurally characterized by using single-crystal X-ray crystallography. Complex 1 exhibits an interdigitated 2D layer with the 2,4L2 topology and 2 is a 2D layer with the sql topology, while 3 and 4 are 3D frameworks resulting from polycatenated 2D nets with the sql topology and 5 and 6 are 2-fold interpenetrated 3D frameworks with the dia topology. Complexes 7 and 8 are 1D looped chains and 9 is a 2D layer with the 3,4L13 topology. The various structural types in 1–9 indicate that the structural diversity is subject to the flexibility and donor atom position of the neutral spacer ligands and the identity of the angular dicarboxylate ligands, while the role of the solvent is uncertain. The iodine adsorption of 1–9 was also investigated, demonstrating that that the flexibility of the spacer L¹–L³ ligands can be an important factor that governs the feasibility of the iodine adsorption. Moreover, complex 9 shows a better iodine adsorption and encapsulates 166.55 mg g⁻¹ iodine in the vapor phase at 60 °C, which corresponded to 0.38 molecules of iodine per formula unit.

A Southeast Asian collaborative Delphi consensus on surveying risk factors for head and neck cancer screening and prevention

The objective of this study was to determine high value questions for early detection and prevention of head and neck cancer by querying content experts on patient risk factors relevant to local communities in Southeast Asia (i.e., Vietnam, Laos, China, and Singapore). The Delphi method was employed using three rounds of asynchronous surveying which included participants among five different collaborating medical centers. 60 total survey items were assessed for consensus defined by a priori measures on the relative level of value of these questions for use in head and neck cancer screening. 77% of items reached a consensus and no items were concluded to be of low value despite differences in conclusions regarding relative importance. Survey items focused on patient demographic information and physical examination were examined across variables such as expert department affiliation, academic designation, and years of experience and found to be without statistically significant differences. However, with consensus items related to social risk factors, it was determined that participants who had 15 or more years of experience or identified as otolaryngologists rated these items at a relatively lower value than their peers with less experience (p < 0.0001, p = 0.0017) or outside the field of otolaryngology (p = 0.0101). This study explicitly identifies patient variables to consider in head and neck cancer screening that have not previously been comprehensively or methodically assessed in current literature. Increasing awareness of these risk factors may benefit the design and implementation of future head and neck cancer early detection and prevention programs in Southeast Asia and beyond as well as positively impact head and neck cancer outcomes.

P–547 Single-cell RNA sequencing identifies molecular regulations associated with poor maturation performance on rescue in vitro matured oocytes

Study question

What is the transcriptome signature associated with rescuein vitro matured (rIVM) oocytes?

Summary answer

GATA–1/CREB1/WNT signaling axis was repressed in rIVM oocytes of poor quality.

What is known already

rIVM aims to produce mature oocytes (MII) for in vitro fertilization (IVF) through IVM of immature oocytes collected from stimulated ovaries. It is less popular due to limited success rate in infertility treatment. Genetic aberrations, cellular stress, and the absence of cumulus cell support in oocytes could account for the failure of rIVM.

Study design, size, duration

We applied single-cell RNA sequencing (scRNA-seq) to capture the transcriptomes of human in vivo (IVO) oocytes (n = 10) from 7 donors and rIVM oocytes (n = 10) from 10 donors, followed by studying the maternal age effect and ovarian responses on rIVM oocyte transcriptomes.

Participants/materials, setting, methods

Human oocytes were collected from donors aged 28–41 years with a body mass index of &lt; 30. RNA extraction, cDNA generation, library construction and sequencing were performed in one preparation. scRNA-seq data were then processed and analyzed. Selected genes in therIVM vs. IVO comparison were validated by quantitative real-time PCR.

Main results and the role of chance

The transcriptome profiles of rIVM/IVO showed distinctive differences. A total of 1559 differentially expressed genes (DEGs, genes with at least two-fold change and adjusted p &lt; 0.05) were found to be enriched in metabolic processes, biosynthesis, and oxidative phosphorylation. Among these DEGs, we identified a repression of WNT/β-catenin signaling in rIVM when compared with IVO oocytes. We found that estradiol level exhibited a significant age-independent correlation with the IVO mature oocyte ratio (MII ratio). rIVM oocytes with higher MII ratio showed over-represented cellular processes such as anti-apoptosis. To further identify targets that contribute to the poor outcomes of rIVM, we compared oocytes collected from young donors with high MII ratio versus donors of advanced maternal age and revealed CREB1was an important regulator in rIVM. Our study identified GATA–1/CREB1/WNT signaling was repressed in both rIVM condition and rIVM oocytes of low-quality.

Limitations, reasons for caution

In the rIVM oocytes of high- and low-quality comparison, the number of samples was limited after data filtering with stringent selection criteria. For the oocyte stage identification, we were unable to predict the presence of oocyte spindle so polar body extrusion was the only indicator.

Wider implications of the findings: This study showed that GATA–1/CREB1/WNT signaling and antioxidant actions were repressed in rIVM condition and was further downregulated in rIVM oocytes of low-quality, providing us the foundation of subsequent follow-up research on human subjects.

Trial registration number

Not applicable

Silver(i) coordination polymers based on halogenated cyanoformamidine: roles of oxyanions and halogen atoms in the structural diversity

Halogen substituents on cyanoformamidine ligands and oxyanions affect the structures of complexes due to differences in their electronegativity and volume.

Zn(ii) and Cd(ii) coordination polymers with a new angular bis-pyridyl-bis-amide: synthesis, structures and sensing properties

Zn(ii) and Cd(ii) coordination polymers that show a 2D double layer with the rare (4⁶·6⁴)-5 L4 topology and a 3D framework with a new (4·5·6)(4⁵·5⁵·6⁹·7·8) topology, respectively, show good selectivity toward the detection of Fe³⁺ ions.

Structural diversity and modification in Ni(ii) coordination polymers: a peculiar phenomenon of reversible structural transformation between a 1D ladder and 2D layer

The coordination of 5-tert-IPA²⁻ ligands, the relaxation of the interdigitated 2D net and the breaking and connecting of the bis-pyridyl-bis-amide ligand demonstrate the peculiar reversible structural transformation between a 1D ladder and 2D layer.

One-dimensional chains based on linear tetranuclear copper(i) units: reversible structural transformation and luminescence change

Two extended metal chains based on linear tetracopper units are reported, in which the bromide complex undergoes reversible structural transformation and luminescence change.

Rapid Nanophotonics Assay for Head and Neck Cancer Diagnosis

Efficient and timely diagnosis of head and neck squamous cell carcinoma (HNSCC) is a critical challenge, particularly in low and middle income countries. These regions, which are expected to witness a drastic increase in HNSCC rates, are ill-prepared to handle the diagnostic burden due to limited resources, especially the low ratio of pathologists per population, resulting in delayed diagnosis and treatment. Here, we demonstrate the potential of an alternative diagnostic method as a low-cost, resource-efficient alternative to histopathological analysis. Our novel technology employs unique surface-enhanced Raman scattering (SERS) "nanorattles" targeting cytokeratin nucleic acid biomarkers specific for HNSCC. In this first study using SERS diagnostics for head and neck cancers, we tested the diagnostic accuracy of our assay using patient tissue samples. In a blinded trial, our technique demonstrated a sensitivity of 100% and specificity of 89%, supporting its use as a useful alternative to histopathological diagnosis. The implications of our method are vast and significant in the setting of global health. Our method can provide a rapid diagnosis, allowing for earlier treatment before the onset of distant metastases. In comparison to histopathology, which can take several months in remote limited-resources regions, our method provides a diagnosis within a few hours.

Reexamining the ideal depth of endotracheal tube in neonates

BACKGROUND

The appropriate endotracheal tube (ET) depth for the newborn with respiratory failure is important. Inappropriate ET depth increases the risk of uneven lung expansion and collapse. This retrospective study aimed to compare the final ideal ET depth with Tochen's formula in Taiwanese intubated neonates, and to determine the correlation between neonatal factors and final ideal ET depth, and to devise an accurate predictive formula for use in Taiwan.

METHODS

Data were collected from neonates who required endotracheal intubation and who were admitted to the Neonatal Intensive Care Unit from 2011 to 2015. Correlations between the final ideal ET depth, GA, and BW were assessed using the Pearson correlation test. Multiple regression analysis was used to produce a formula to predict appropriate ET depth from mouth angle to midtracheal position of neonates.

RESULTS

A total of 139 neonates were enrolled in this study. The final ideal ET depth was in concordance with Tochen's formula only in 19 neonates (13.7%); relatively deeper in 30 (21.6%) neonates; and shallower than the values from Tochen's formula in 90 (64.7%) neonates. Multiple regression analysis showed that the BW and GA together produced best prediction for final ideal ET depth in our study population. SGA and gender were shown to be insignificantly related to final ideal ET depth.

CONCLUSION

Our study showed the final ideal ET depth was shallower than Tochen's formula in 64.7% of neonates. Tochen's formula might not be suitable to predict ET depth for neonates in Taiwan. In our study, the new formula: 4.0 + 1.0 BW (kg) + 0.05 GA (weeks) provides a more accurate value and alternative method for evaluating the final ideal ET depth in Taiwan. A practical guideline for Asian neonates should be validated by prospective studies with large sample sizes.

Microplastic ingestion reduces energy intake in the clam Atactodea striata

The effects of microplastic concentrations (10itemsl^-1 and 1000itemsl^-1) on the physiological responses of Atactodea striata (clearance rate, absorption efficiency, respiration rate) were investigated. The fates of ingested microplastics and the efficiency of depuration in removing ingested microplastics were also studied. A. striata ingested microplastics and the clearance rate was reduced at high concentration of microplastics. Since the respiration rate and absorption efficiency remained unchanged in exposed A. striata, reduction in the clearance rate would reduce the energy intake. Ingestion and retention of microplastics in the body were further limited by the production of pseudofaeces and faeces, and depuration in clean water, resulting in a very small amount of microplastics stored in the body of the clam.

Squamous Cell Carcinoma DNA Detection Using Ultrabright SERS Nanorattles and Magnetic Beads for Head and Neck Cancer Molecular Diagnostics

A rise in head and neck cancers in low and middle countries over recent years has prompted the need for low-cost, resource-efficient diagnostic technologies. Standard diagnosis with histopathology is often not feasible due to the low number of trained pathologists in these regions, resulting in delayed diagnosis and treatment. This study presents an alternative diagnostic method to standard histopathology. We developed a surface enhanced raman scattering (SERS) based method to distinguish squamous cell carcinoma from other cell lines. Using a "sandwich" method employing ultrabright SERA nanorattles and magnetic beads, we directly targeted specific nucleic acid markers of squamous cells. Our method was able to detect the presence of squamous cells with high sensitivity and specificity, supporting its potential for use as a diagnostic tool in head and neck fine needle aspirations (FNA).

Probing the magnetic profile of diluted magnetic semiconductors using polarized neutron reflectivity

Room temperature ferromagnetism has been observed in the Cu doped ZnO films deposited under an oxygen partial pressure of 10^-3 and 10^-5 torr on Pt (200 nm)/Ti (45 nm)/Si (001) substrates using pulsed laser deposition. Due to the deposition at relatively high temperature (873 K), Cu and Ti atoms diffuse to the surface and interface, which significantly affects the magnetic properties. Depth sensitive polarized neutron reflectometry method provides the details of the composition and magnetization profiles and shows that an accumulation of Cu on the surface leads to an increase in the magnetization near the surface. Our results reveal that the presence of the copper at Zn sites induces ferromagnetism at room temperature, confirming intrinsic ferromagnetism.

Ventilator-Associated Pneumonia in Low Birth Weight Neonates at a Neonatal Intensive Care Unit: A Retrospective Observational Study

BACKGROUND

Ventilator-associated pneumonia (VAP) is one of the most common healthcare-associated infections among ventilated patients. The aim of this study was to determine the clinical characteristics and risk factors for the development of VAP in intubated low birth weight (LBW) neonates in a neonatal intensive care unit.

METHODS

LBW infants (<2.5 kg) admitted to the neonatal intensive care unit of Kaohsiung Medical University Hospital from January 2005 to December 2009 were enrolled. We retrospectively analyzed perinatal and neonatal data of the enrolled intubated LBW infants by chart review.

RESULTS

Six hundred and five LBW infants were analyzed. One hundred and fourteen of the infants were intubated for >48 hours, 15 (13.2%) of whom had VAP. Of these 15 patients, the average age at onset of VAP was 24.0 ± 11.2 days, the average postmenstrual age was 30.6 ± 1.8 weeks, and the mean gestational age was 27.1 ± 2.3 weeks, which was significantly lower than the mean gestational age in the group without VAP (30.2 ± 3.5 weeks). The mean birth body weight was 944.4 ± 268.4 g in the VAP group and 1340.1 ± 455.4 g in the group without VAP (p < 0.001). Longer duration of intubation (odds ratio: 1.35, 95% confidence interval: 1.12-1.62) and parenteral nutrition (odds ratio: 1.32, 95% confidence interval: 1.14-1.51) were found in the VAP group after adjusting for gestational age and birth weight.

CONCLUSION

VAP was a problem for the LBW infants with intubation for >48 hours in our neonatal intensive care unit. VAP most frequently occurred at a postmenstrual age of 30-32 weeks in this study. Longer duration of tube placement and parenteral nutrition were found in the VAP group. Early removal of the endotracheal tube and adequate enteral nutrition may decrease the occurrence of VAP in LBW infants.

Postnatal Changes in Tibial Bone Speed of Sound of Preterm and Term Infants during Infancy

This study aimed to evaluate changes in tibial bone speed of sound (SOS) over time, in preterm and term infants during infancy, in addition to identifying factors influencing the development of tibial SOS during infancy. Preterm (n = 155) and term (n = 65) infants were enrolled in this study. Tibial bone SOS was measured using quantitative ultrasonography (QUS) on the left tibia of newborn infants after birth (within 7 days), at 1 month old, and then every 2 months until subjects were approximately 12-15 months old. Follow-up checks included anthropometric measurements and tibial bone SOS. Mean tibial bone SOS at birth was significantly higher in term infants (mean ± SD, 2968.5 ± 99.7 m/s) than in preterm infants (2912.2 ± 122.6 m/s). Values of follow-up tibial bone SOS declined for the first 4 months, and then increased gradually until 12-15 months old. This increasing trend was greater in preterm infants after 2 months of corrected age than in term infants. There were no significant differences by 12-15 months of age between preterm and term infants. A longitudinal mixed-effect model controlling for internal correlations and other covariates in the two groups showed that age and the SOS value at birth were important factors affecting the tibial bone SOS in both preterm and term newborn infants during infancy. There are significant differences in the pattern of change in tibial bone SOS values between preterm and term infants during the first 12-15 months of life. Age and SOS value at birth were important factors affecting the pattern of tibial bone SOS change in both preterm and term newborn infants during infancy.

Neurodevelopmental Outcomes in Very Low Birth Weight Infants Using Aminophylline for the Treatment of Apnea

BACKGROUND

Aminophylline has been widely used in the treatment of apneic episodes in premature infants. Animal models suggest caution in the use of aminophylline as it may increase the cerebral metabolic rate and decrease the rate of anoxic survival in neonates. This study aimed to evaluate the neurological outcomes in very low birth weight (VLBW) infants treated with aminophylline for apnea in our neonatal intensive care unit.

METHODS

All VLBW infants (body birth weight < 1500 g) admitted to our neonatal intensive care unit between January 2000 and December 2011 were enrolled in this retrospective study. Clinical characteristics and outcomes of these infants were reviewed and recorded. Scores on the Bayley Scales of Infant Development at 6 months, 12 months, and 18 months of corrected age were also recorded. The controls (who did not receive aminophylline) were matched for gestational age with the aminophylline group.

RESULTS

The baseline characteristics of the aminophylline group and the control group were similar. The neurodevelopmental outcomes as well as rates of patent ductus arteriosus, brain injury, severe retinopathy of prematurity, and necrotizing enterocolitis were not significantly different between the two groups. Only bronchopulmonary dysplasia remained significantly higher in the aminophylline group after adjusting for risk factors (48.08% vs. 21.15%; adjusted odds ratio: 12.50; p < 0.001).

CONCLUSION

Aminophylline therapy for apnea of prematurity had no apparent and additional risk on the neurodevelopmental outcomes of VLBW infants at a corrected age of 18 months. Further studies with a larger sample size are needed to confirm the adverse neurological effects of aminophylline treatment.

Lung function in very preterm infants with patent ductus arteriosus under conservative management: an observational study

Background

Persistent patent ductus arteriosus (PDA) during hospitalization is thought to be associated with adverse pulmonary outcomes in very preterm infants. This observational study aimed to compare the lung function in very preterm infants with and without PDA at discharge.

Methods

Very preterm infants, admitted to our neonatal intensive unit, who required respiratory support soon after birth and had undergone a lung function test at discharge, were enrolled. Infants with a need for positive-pressure support (either an invasive ventilator, or nasal continuous positive airway pressure without oxygen) or supplemental oxygen at a postmenstrual age of 36 weeks were defined as having bronchopulmonary dysplasia (BPD). Echocardiography was performed weekly for each of the very preterm infants with PDA to confirm closure of the PDA. The data were collected retrospectively.

Results

Fifty-two very preterm infants received lung function tests before discharge during the study period, 28 of whom had PDA and received conservative management, and 20 who did not. The other 4 infants who were given active treatment for PDA were excluded. Gestational age was significantly smaller in the PDA group than in the no-PDA group (27.1 ± 2.0 vs. 28.6 ± 1.6 weeks, p = 0.009). Birth weight did not differ significantly in those with and those without PDA (0.98 ± 0.26 vs. 1.12 ± 0.26 kg, p = 0.074). Significantly more infants with PDA had BPD (p = 0.002) and required respiratory support for a longer period (p = 0.001) than those without PDA. However, functional residual capacity (ml/kg) at discharge was comparable between the two groups after adjusting for gestational age and postmenstrual age at testing (21.6 ± 8.4 vs. 21.5 ± 6.7 ml/kg, p = 0.894). Other lung function test parameters were also comparable.

Conclusion

Under a definition of BPD (including infants needing CPAP but without oxygen) other than the conventional definition, the very preterm infants in our study who received conservative management for PDA had a higher percentage of BPD than the infants without PDA. The parameters of the lung function test and lung clearance index were comparable between these two groups at discharge.

Predictive power of serial neonatal therapeutic intervention scoring system scores for short-term mortality in very-low-birth-weight infants

BACKGROUND

The Neonatal Therapeutic Intervention Scoring System (NTISS) is used to indicate disease severity for neonates who need intensive care. We examined the ability of serial NTISS scores to predict mortality in very-low-birth-weight preterm infants.

METHODS

We reviewed the medical records of all preterm infants that had a birth weight of <1500 g and were admitted to a neonatal intensive care unit from 2007 to 2011. We calculated the NTISS scores at 24 hours, 48 hours, and 72 hours after admission, and assessed the predictive power for mortality using receiver-operating characteristic curve and area under the curve analysis. We also constructed a predictive model with gestational age, birth weight, and NTISS scores to predict mortality in these very-low-birth-weight infants.

RESULTS

In total, 172 infants were enrolled into this study. Eighteen (10.5%) infants died in the first 7 days after birth. The area under the curve of the NTISS score was 0.913 at 24 hours, 0.955 at 48 hours, and 0.958 at 72 hours. However, there was no significant difference in the overall average NTISS scores between 48 hours and 72 hours. The NTISS score at 48 hours was a better predictor of mortality than that at 24 hours after admission. Combining gestational age, birth weight, and NTISS score at 48 hours, birth weight was found to contribute little to the predictive power of mortality. The model with gestational age and NTISS score at 48 hours had a better predictive power than the NTISS score alone (area under the curve = 0.99).

CONCLUSION

The NTISS score at 48 hours seemed to be effective to predict mortality in preterm infants whose birth weight was less than 1500 g. In addition, gestational age played a more important role in predicting mortality than birth weight.

Neutron spin evolution through broadband current sheet spin flippers

Controlled manipulation of neutron spin is a critical tool for many neutron scattering techniques. We have constructed current-sheet, neutron spin flippers for use in Spin Echo Scattering Angle Measurement (SESAME) that comprise pairs of open-faced solenoids which introduce an abrupt field reversal at a shared boundary. The magnetic fields generated by the coils have been mapped and compared with both an analytical approximation and a numerical boundary integral calculation. The agreement is generally good, allowing the former method to be used for rapid calculations of the Larmor phase acquired by a neutron passing through the flipper. The evolution of the neutron spin through the current sheets inside the flipper is calculated for various geometries of the current-carrying conductors, including different wire shapes, arrangements, and common imperfections. The flipping efficiency is found to be sensitive to gaps between wires and between current sheets. SESAME requires flippers with high fields and flipping planes inclined to the neutron beam. To avoid substantial neutron depolarization, such flippers require an interdigitated arrangement of wires.

Spin exchange optical pumping based polarized 3He filling station for the Hybrid Spectrometer at the Spallation Neutron Source

The Hybrid Spectrometer (HYSPEC) is a new direct geometry spectrometer at the Spallation Neutron Source at the Oak Ridge National Laboratory. This instrument is equipped with polarization analysis capability with 60° horizontal and 15° vertical detector coverages. In order to provide wide angle polarization analysis for this instrument, we have designed and built a novel polarized (3)He filling station based on the spin exchange optical pumping method. It is designed to supply polarized (3)He gas to HYSPEC as a neutron polarization analyzer. In addition, the station can optimize the (3)He pressure with respect to the scattered neutron energies. The depolarized (3)He gas in the analyzer can be transferred back to the station to be repolarized. We have constructed the prototype filling station. Preliminary tests have been carried out demonstrating the feasibility of the filling station. Here, we report on the design, construction, and the preliminary results of the prototype filling station.

Intake of phthalate-tainted foods alters thyroid functions in Taiwanese children

BACKGROUND

On April-May, 2011, two Taiwan chemical companies were found to have intentionally added phthalates, Di-(2-ethylhexyl) phthalate (DEHP) and/or Di-isononyl phthalate, as a substitute of emulsifier to many foodstuffs. This study aimed to investigate whether exposure to these foods altered endocrine functions in children aged ≤10 years and, if so, whether those changes could be reversed by stopping exposure.

METHODS

One Phthalates Clinic for Children was established in southern Taiwan between May 31 and June 17, 2011. All eligible children had their exposure information, blood and/or urine specimens collected. Endocrine functions were assessed in serum. The exposure groups were categorized into three (High, >500 ppm, Low, 1-500 ppm, and No, <1 ppm of DEHP). After six months, some children were followed up for the selected endocrine hormones.

RESULTS

Sixty children were eligible in this study; all were Tanner stage 1 with no pubic hair. Compared to non-exposed group, both high and low exposure groups had significantly lower serum thyroid-stimulating hormone (TSH) levels (P = 0.001 and 0.024). At six months follow-up, serum triiodothyronine (T3) levels was significantly changed (P = 0.034) in high exposure group (n = 13). For serum estradiol (E2), the detectable rate (≥8 pg/mL) decreased from 76.9% (10/13) to 30.8% (4/13) (P = 0.070).

CONCLUSIONS

This study shows that serum TSH levels can be altered when children were exposed to high concentrations of phthalate-tainted foodstuffs. Serum E2 and T3 may be partially recovered after stopping exposure.

A non-oncogenic HPV 16 E6/E7 vaccine enhances treatment of HPV expressing tumors

Human papillomaviruses (HPVs) are the causative factor for >90% of cervical cancers and 25% of head and neck cancers. The incidence of HPV positive (+) head and neck squamous cell carcinomas has greatly increased in the last 30 years. E6 and E7 are the two key viral oncoproteins that induce and propagate cellular transformation. An immune response generated during cisplatin/radiation therapy improves tumor clearance of HPV(+) cancers. Augmenting this induced response during therapy with an adenoviral HPV16 E6/E7 vaccine improves long-term survival in pre-clinical models. Here, we describe the generation of an HPV16 E6/E7 construct, which contains mutations that render E6/E7 non-oncogenic, while preserving antigenicity. These mutations do not allow E6/E7 to degrade p53, pRb, PTPN13, or activate telomerase. Non-oncogenic E6/E7 (E6(Δ)/E7(Δ)) expressed as a stable integrant, or in the [E1-, E2b-] adenovirus, lacks the ability to transform human cells while retaining the ability to induce an HPV-specific immune response. Moreover, E6(Δ)/E7(Δ) plus chemotherapy/radiation statistically enhances clearance of established HPV(+) cancer in vivo.

In situ polarized 3He system for the Magnetism Reflectometer at the Spallation Neutron Source

We report on the in situ polarized (3)He neutron polarization analyzer developed for the time-of-flight Magnetism Reflectometer at the Spallation Neutron Source at Oak Ridge National Laboratory. Using the spin exchange optical pumping method, we achieved a (3)He polarization of 76% ± 1% and maintained it for the entire three-day duration of the test experiment. Based on transmission measurements with unpolarized neutrons, we show that the average analyzing efficiency of the (3)He system is 98% for the neutron wavelength band of 2-5 Å. Using a highly polarized incident neutron beam produced by a supermirror bender polarizer, we obtained a flipping ratio of >100 with a transmission of 25% for polarized neutrons, averaged over the wavelength band of 2-5 Å. After the cell was depolarized for transmission measurements, it was reproducibly polarized and this performance was maintained for three weeks. A high quality polarization analysis experiment was performed on a reference sample of Fe/Cr multilayer with strong spin-flip off-specular scattering. Using a combination of the position sensitive detector, time-of-flight method, and the excellent parameters of the (3)He cell, the polarization analysis of the two-dimensional maps of reflected, refracted, and off-specular scattered intensity above and below the horizon were obtained, simultaneously.

The long-term effect of listening to Mozart K.448 decreases epileptiform discharges in children with epilepsy

Mozart's Sonata for Two Pianos in D major, K.448 (Mozart K.448), has been shown to improve mental function, leading to what is known as the Mozart Effect. Our previous work revealed that epileptiform discharges in children with epilepsy decrease during and right after listening to Mozart K.448. However, the duration of the effect was not studied. In the study described here, we evaluated the long-term effect of Mozart K.448 on epileptiform discharges in children with epilepsy. Eighteen children with epilepsy whose seizures were clinically well controlled with antiepileptic drugs were included. For each child, EEGs had revealed persistent epileptiform discharges for at least 6 months. These patients listened to Mozart K.448 for 8 minutes once a day before bedtime for 6 months. Epileptiform discharges were recorded and compared before and after 1, 2, and 6 months of listening to Mozart K.448. All of the children remained on the same antiepileptic drug over the 6 months. Relationships between number of epileptiform discharges and foci of discharges, intelligence, epilepsy etiology, age, and gender were analyzed. Epileptiform discharges significantly decreased by 53.2±47.4, 64.4±47.1, and 71.6±45.8%, respectively, after listening to Mozart K.448 for 1, 2, and 6 months. All patients except those with occipital discharges showed a significant decrease in epileptiform discharges. Patients with normal intelligence and idiopathic epilepsy had greater decreases than those with mental retardation and symptomatic epilepsy. Age and gender did not affect the results. We conclude that long-term listening to Mozart K.448 may be effective in decreasing epileptiform discharges in children with epilepsy in a chronologically progressive manner.

Bubble nucleation in stout beers

Bubble nucleation in weakly supersaturated solutions of carbon dioxide-such as champagne, sparkling wines, and carbonated beers-is well understood. Bubbles grow and detach from nucleation sites: gas pockets trapped within hollow cellulose fibers. This mechanism appears not to be active in stout beers that are supersaturated solutions of nitrogen and carbon dioxide. In their canned forms these beers require additional technology (widgets) to release the bubbles which will form the head of the beer. We extend the mathematical model of bubble nucleation in carbonated liquids to the case of two gases and show that this nucleation mechanism is active in stout beers, though substantially slower than in carbonated beers and confirm this by observation. A rough calculation suggests that despite the slowness of the process, applying a coating of hollow porous fibers to the inside of a can or bottle could be a potential replacement for widgets.

Urinary dopamine in aromatic L-amino acid decarboxylase deficiency: the unsolved paradox

INTRODUCTION

In aromatic L-amino acid decarboxylase (AADC) deficiency, a neurotransmitter biosynthesis defect, paradoxical normal or increased levels of urinary dopamine have been reported. Genotype/phenotype correlations or alternative metabolic pathways may explain this remarkable finding, but were never studied systematically.

METHODS

We studied the mutational spectrum and urinary dopamine levels in 20 patients with AADC-deficiency. Experimental procedures were designed to test for alternative metabolic pathways of dopamine production, which included alternative substrates (tyramine and 3-methoxytyrosine) and alternative enzymes (tyrosinase and CYP2D6).

RESULTS/DISCUSSION

In 85% of the patients the finding of normal or increased urinary levels of dopamine was confirmed, but a relation with AADC genotype could not be identified. Renal microsomes containing CYP2D were able to convert tyramine into dopamine (3.0 nmol/min/g protein) but because of low plasma levels of tyramine this is an unlikely explanation for urinary dopamine excretion in AADC-deficiency. No evidence was found for the production of dopamine from 3-methoxytyrosine. Tyrosinase was not expressed in human kidney.

CONCLUSION

Normal or increased levels of urinary dopamine are found in the majority of AADC-deficient patients. This finding can neither be explained by genotype/phenotype correlations nor by alternative metabolic pathways, although small amounts of dopamine may be formed via tyramine hydroxylation by renal CYP2D6. CYP2D6-mediated conversion of tyramine into dopamine might be an interesting target for the development of new therapeutic strategies in AADC-deficiency.

Seasonal 25-hydroxyvitamin D changes in British postmenopausal women at 57 degrees N and 51 degrees N: a longitudinal study

The UK has insufficient intensity of sunlight at wavelengths 290-315 nm to enable cutaneous synthesis of vitamin D from October to April. There are regional differences in UVB strength throughout the UK but whether this translates to differences in vitamin D status is not known. We have reported seasonal variations in a cross-sectional study of over 3000 Scottish women in Aberdeen. The aim of this longitudinal study was to compare the seasonal variation of serum 25-hydroxyvitamin D [25(OH)D] in postmenopausal women residing in Aberdeen (57 degrees N) and Surrey (51 degrees N). Women attended 3-monthly visits over 12 months, starting summer 2006. In Aberdeen, 338 Caucasian women (mean age+/-SD, 61.7+/-1.5 years); and at Surrey, 138 Caucasian women (61.4+/-4.5 years) and 35 Asian women (59.9+/-6.4 years) had serum 25(OH)D measured by IDS enzyme immunoassay. In winter/spring none of the Caucasian women living in Surrey had 25(OH)D<20 nmol/L, but nearly a quarter of women in Aberdeen were vitamin D-deficient. This number decreased to 4.2% in summer/autumn. For the Asian women 17.1% were vitamin D-deficient in summer, increasing to 58.1% in winter. Using higher 25(OH)D deficiency cut-offs, the percentage of women affected was much higher. These longitudinal data show clear differences in vitamin D status between the north and south of the UK, and marked ethnic differences. They are consistent with our previous data and with cross-sectional data from the 1958 birth cohort. The low vitamin D status may have implications for bone health and other health outcomes, which is currently being investigated in this publication group. The extent of vitamin D deficiency in Asian women residing in the South of England is of concern.

Clinical and biochemical features of aromatic L-amino acid decarboxylase deficiency

OBJECTIVE

To describe the current treatment; clinical, biochemical, and molecular findings; and clinical follow-up of patients with aromatic l-amino acid decarboxylase (AADC) deficiency.

METHOD

Clinical and biochemical data of 78 patients with AADC deficiency were tabulated in a database of pediatric neurotransmitter disorders (JAKE). A total of 46 patients have been previously reported; 32 patients are described for the first time.

RESULTS

In 96% of AADC-deficient patients, symptoms (hypotonia 95%, oculogyric crises 86%, and developmental retardation 63%) became clinically evident during infancy or childhood. Laboratory diagnosis is based on typical CSF markers (low homovanillic acid, 5-hydroxyindoleacidic acid, and 3-methoxy-4-hydroxyphenolglycole, and elevated 3-O-methyl-l-dopa, l-dopa, and 5-hydroxytryptophan), absent plasma AADC activity, or elevated urinary vanillactic acid. A total of 24 mutations in the DDC gene were detected in 49 patients (8 reported for the first time: p.L38P, p.Y79C, p.A110Q, p.G123R, p.I42fs, c.876G>A, p.R412W, p.I433fs) with IVS6+ 4A>T being the most common one (allele frequency 45%).

CONCLUSION

Based on clinical symptoms, CSF neurotransmitters profile is highly indicative for the diagnosis of aromatic l-amino acid decarboxylase deficiency. Treatment options are limited, in many cases not beneficial, and prognosis is uncertain. Only 15 patients with a relatively mild form clearly improved on a combined therapy with pyridoxine (B6)/pyridoxal phosphate, dopamine agonists, and monoamine oxidase B inhibitors.

Heat shock pretreatment attenuates sepsis-associated encephalopathy in LPS-induced septic rats

Sepsis is the most common cause of mortality in intensive care units. Although sepsis-associated encephalopathy (SAE) is reported to be a leading manifestation of sepsis, its pathogenesis remains unclear. In our previous studies, we showed that heat shock pretreatment can reduce mortality in polymicrobial septic rats and protect the cerebral cortical function during hypoxia or drug-induced convulsion. In the present study, we investigated to what extent heat shock pretreatment might affect the development of SAE in septic rats and the possible mechanism behind its effect was discussed. To do this, we used lipopolysaccharide (LPS) to induce septic response in a SAE animal model. Heat shock pretreatment was performed and rectal temperature maintained between 41 and 42 degrees C for 15 min using an electric heating pad. Electroencephalography (EEG) activity, a sensitive electrophysiological recording of electrical activity in the brain, was used as an indicator of cerebral cortical dysfunction in SAE. In LPS rats not pretreated with heat shock, the EEG background activity decreased 10 min after intraperitoneal administration of LPS. However, in rats pretreated with heat shock, this decrease was significantly attenuated. Untreated septic rats were also found to have earlier, more frequent epileptic spikes. In summary, we found that heat shock could attenuate the electro-cortical dysfunction in rats with LPS-induced septic response, suggesting that heat shock response might potentially be used to prevent SAE in sepsis.

Phase synchronization analysis by assessment of the phase difference gradient

Phase synchronization is an important phenomenon of nonlinear dynamics and has recently received much scientific attention. In this work a method for identifying phase synchronization epochs is described which focuses on estimating the gradient of segments of the generalized phase differences between phase slips in an experimental time series. In phase synchronized systems, there should be a zero gradient of the generalized phase differences even if the systems are contaminated by noise. A method which tests if the gradient of the generalized phase difference is statistically different from zero is reported. The method has been validated by numerical studies on model systems and by comparing the results to those published previously. The method is applied to cardiorespiratory time series from a human volunteer measured in clinical settings and compared to synchrogram analysis for the same data. Potential problems with synchrogram analysis of experimental data are discussed.

Fluid—structure interaction in axially symmetric models of abdominal aortic aneurysms

Abdominal aortic aneurysm disease progression is probably influenced by tissue stresses and blood flow conditions and so accurate estimation of these will increase understanding of the disease and may lead to improved clinical practice. In this work the blood flow and tissue stresses in axially symmetric aneurysms are calculated using a complete fluid—structure interaction as a benchmark for calculating the error introduced by simpler calculations: rigid walled for the blood flow, homogeneous pressure for the tissue stress, as well as one-way-coupled interactions. The error in the peak von Mises stress in a homogeneous pressure calculation compared with a fluid—structure interaction calculation was less than 3.5 per cent for aneurysm diameters up to 7 cm. The error in the mean wall shear stress, in a rigid-walled calculation compared with a fluid—structure interaction calculation, varied from 30 per cent to 60 per cent with increasing aneurysm diameter. These results suggest that incorporation of the fluid—structure interaction is unnecessary for purely mechanical modelling, with the aim of evaluating the current rupture probability. However, for more complex biological modelling, perhaps with the aim of predicting the progress of the disease, where accurate estimation of the wall shear stress is essential, some form of fluid—structure interaction is necessary.

Effect of the Chinese herb extract osthol on IL-4-induced eotaxin expression in BEAS-2B cells

BACKGROUND

Asthma is an allergic inflammatory disease of the airways. The interaction between bronchial epithelial cells and eosinophils is an important feature of an asthma attack. Eotaxin, an eosinophil-specific C-C chemokine, is a potent chemoattractant involved in the mobilization of eosinophils into the airway after allergic stimulation. Cnidii monnieri fructus, the dried fruit of Cnidium monnieri Cusson, has been used as an antipruritogenic agent in ancient China. OsthoL is the major component of Cnidii monnieri fructus extract. We investigated the ability of osthol to regulate cytokine-induced eotaxin expression in the human bronchial epithelial cell line BEAS-2B.

METHODS

BEAS-2B cells were pretreated with osthol at different concentrations (0.1-10 microM), and then stimulated with interleukin (IL)-4 alone, or in combination with tumor necrosis factor (TNF)-alpha. Eotaxin levels were determined by real-time reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. STAT6 (signal transducer and activator of transcription 6) and MAPK (mitogen-activated protein kinase) expressions were evaluated by Western blotting, to detect possible intracellular signal transduction.

RESULTS

IL-4 and TNF-alpha significantly induced eotaxin expression in BEAS-2B cells. Expression of eotaxin was suppressed by osthol (0.1-10 microM) in a dose-dependent manner. Osthol did not suppress IL-4-induced p38, ERK or JNK expression. Osthol did suppress IL-4-induced STAT6 in a dose-dependent manner.

CONCLUSION

Osthol suppressed IL-4-induced eotaxin in BEAS-2B cells via inhibition of STAT6 expression. This data suggest that osthol might have potential for treating allergic airway inflammation.

The use of symmetry to correct Larmor phase aberrations in spin echo scattering angle measurement

Spin echo scattering angle measurement (SESAME) is a sensitive interference technique for measuring neutron diffraction. The method uses waveplates or birefringent prisms to produce a phase separation (the Larmor phase) between the "up" and "down" spin components of a neutron wavefunction that is initially prepared in a state that is a linear combination of in-phase up and down components. For neutrons, uniformly birefringent optical elements can be constructed from closed solenoids with appropriately shaped cross sections. Such elements are inconvenient in practice, however, both because of the precision they demand in the control of magnetic fields outside the elements and because of the amount of material required in the neutron beam. In this paper, we explore a different option in which triangular-cross-section solenoids used to create magnetic fields for SESAME have gaps in one face, allowing the lines of magnetic flux to "leak out" of the solenoid. Although the resulting field inhomogeneity produces aberrations in the Larmor phase, the symmetry of the solenoid gaps causes the aberrations produced by neighboring pairs of triangular solenoids to cancel to a significant extent. The overall symmetry of the SESAME apparatus leads to further cancellations of aberrations, providing an architecture that is easy to construct and robust in performance.

Ectopic Pancreatic Tissue Presenting as an Umbilical Mass in a Newborn: A Case Report

The case of an ectopic pancreatic mass at the umbilicus in an 8-day-old male neonate is reported, the youngest patient with this condition ever reported in an English-language journal. The patient was healthy except for a protruding mass with intermittent mucous discharge at the base of the umbilical stump. Surgical intervention was performed under the impression of the umbilical mass. Pathology diagnosed an ectopic pancreas with acute hemorrhage. To the best of our knowledge, only one case of ectopic pancreas presenting as an umbilical mass with intermittent mucous discharge has previously been reported.

MEG localization of rolandic spikes with respect to SI and SII cortices in benign rolandic epilepsy

The purpose of this study was to study the relationship between interictal spike sources and somatosensory cortices in benign rolandic epilepsy of childhood (BREC) using a whole-scalp neuromagnetometer. We recorded spontaneous magnetoencephalography (MEG) and EEG signals and cortical somatosensory-evoked magnetic fields (SEFs) to electric stimulation of the median nerve in 9 children with BREC. Interictal rolandic discharges (RDs) and SEFs were analyzed by equivalent current dipole (ECD) modeling. Based on the orientation and locations of corresponding ECDs, we compared generators of RDs with primary (SI) and second somatosensory cortices (SII). Our results showed that RDs and SII responses had similar ECD orientation on the magnetic field maps. The ECDs of RDs were localized 15.3 +/- 1.9 and 12.2 +/- 2.8 mm anterior to SI and SII, respectively. The spatial distance on average from the location of RDs to SII (21.9 +/- 1.6 mm) cortex was significantly shorter than to SI cortex (29.7 +/- 1.7 mm) (P<0.01, Wilcoxon signed-rank test). In conclusion, the cortical generators for RDs in patients with BREC are localized in the precentral motor cortex, closer to hand SII than to SI cortex.

Familial risk of allergic rhinitis and atopic dermatitis among Chinese families in Singapore

INTRODUCTION

This study aims to determine the familial risk of atopic dermatitis (AD) and allergic rhinitis (AR) in Chinese children.

MATERIALS AND METHODS

A cross-sectional study was conducted in a housing estate in Singapore. Data was collected using an interviewer-administered questionnaire. Participants included 257 Chinese families. Prevalence rate ratios (PRRs) and 95% confidence interval (CI) were calculated.

RESULTS

For AD in all children, an increasing trend was found with PRRs of 1.9 (95% CI, 0.3 to 11.8) and 1.5 (95% CI, 0.4 to 5.5) for only father and only mother affected, respectively, to 2.3 (95% CI, 0.4 to 13.7) for both parents affected. In AR, a PRR of 2.7 (95% CI, 1.8 to 3.9) and 2.2 (95% CI, 1.5 to 3.2) for only father and only mother affected, respectively, and 4.5 (95% CI, 3.3 to 6.1) for both affected was found. The PRR (2.2; 95% CI, 1.4 to 3.7) of the first child developing AR when paternal or maternal history was positive was similar. This rose to 3.4 (95% CI, 2.2 to 5.1) when both parents also had AR. The PRR of the second child developing AR was 3.9 (95% CI, 1.7 to 8.9) when the first child alone was positive for AR and 7.0 (95% CI, 3.5 to 13.9) when both parents and the eldest child had AR.

CONCLUSION

A positive family history increases the risk of developing AD and AR with increasing risk dependent on number of relatives affected. The second child's risk of AR is also associated with AR in the first child, suggesting mechanisms of incomplete penetrance.

The mechanisms of neuronal death produced by mitochondrial toxin 3-nitropropionic acid: the roles of N-methyl-D-aspartate glutamate receptors and mitochondrial calcium overload

Previous studies showed that 3-nitropropionic acid, an irreversible inhibitor of succinate dehydrogenase, produced neuronal death secondary to perturbed intracellular calcium homeostasis. However, the response of intramitochondrial calcium ([Ca(2+)](m)) to 3-nitropropionic acid remains unknown. In this study, we investigated the roles of and relationships among [Ca(2+)](m) overload, mitochondrial reactive oxygen species, and mitochondrial membrane depolarization in 3-nitropropionic acid-induced neuronal death. Following 1 mM 3-nitropropionic acid treatment on primary rat neuronal cultures, there was a gradual increase of [Ca(2+)](m) beginning at 2-4 h post 3-nitropropionic acid application, and a twofold increase of mitochondrial reactive oxygen species at 4 h. These were followed by mitochondrial membrane depolarization at 6-8 h post-treatment. By inhibiting [Ca(2+)](m) uptake, Ruthenium Red attenuated the production of reactive oxygen species, and prevented the 3-nitropropionic acid-induced mitochondrial membrane depolarization and 70% of apoptotic neuronal death (P<0.001). Inhibition of caspase activation attenuated the elevation of [Ca(2+)](m) (P<0.001), indicating that caspase activation plays a role in the elevation of [Ca(2+)](m). MK-801, an antagonist of N-methyl-D-aspartate (NMDA) glutamate receptors, prevented 3-nitropropionic acid-induced [Ca(2+)](m) elevation, caspase-3 activation, mitochondrial depolarization, and neuronal death. We conclude that the activation of NMDA glutamate receptor contributes to mitochondrial alterations induced by 3-nitropropionic acid. Inhibition of its activation and [Ca(2+)](m) overload with subsequent mitochondrial membrane depolarization can therefore attenuate the neuronal death induced by 3-nitropropionic acid.

Early epileptic encephalopathy with suppression burst electroencephalographic pattern--an analysis of eight Taiwanese patients

Early epileptic encephalopathy with suppression burst (SB) comprises two distinct epileptic syndromes, early infantile epileptic encephalopathy (EIEE) and early myoclonic encephalopathy (EME). We reviewed etiologies, neurological outcome and clinico-electroencephalographic features of EIEE and EME. Chart records of early epileptic encephalopathy with SB from January 1997 to December 2000 were reviewed. These cases fulfilled the diagnostic criteria of EIEE and EME. Totally eight patients (four females, four males) were enrolled. They consisted of three cases of EIEE and five cases of EME. The follow-up periods ranged from 6 to 30 months. For EIEE, two cases had migrational disorders, and one was cryptogenic; for EME, three cases had non-ketotic hyperglycinemia (NKH), one was pyridoxine dependency and one was cryptogenic. The main initial seizure patterns were tonic spasms in EIEE, and were erratic myoclonus in EME. The age of seizure onset ranged from 26 h to 5 days after birth for EIEE, and 2 h to 7 days of life for EME. The SB pattern in the electroencephalography (EEG) was noted mainly during sleep state in EME, but in both awake and sleep states in EIEE. Asymmetric SB pattern and background activities in EEG were found in migrational disorders. The EEG in all cases of EIEE changed to hypsarrhythmia at 4-6 months of age. In EME, only the EEG in cases of NKH evolved to hypsarrhythmia. Response to anti-convulsants was generally poor. All had severe psychomotor retardation. Although EIEE and EME share several common features, differences in terms of seizure seminology and evolution, EEG patterns and etiologies still exist.

Human papilloma virus type 16 E7 genes protect astrocytes against apoptotic and necrotic death induced by hydrogen peroxide

Hydrogen peroxide is considered to be a dose- and time-dependent mediator in apoptotic and necrotic death. In this study, we examined the signaling of the E6 and E7 proteins with respect to apoptosis or necrosis after H2O2 injury using an in vitro model with overexpressed E6 or E7 genes. For this purpose, the E6 and E7 gene expressing astrocytes were exposed to 10 micromole and 200 micromole H2O2 solutions. Twenty- four hours after treatment with the lower dosage(10 micromole H2O2), control, E6-expressing cells suffered about 45% injury and LXSN-expressing cells decreased by 67% as assessed by LDH release. However, E7-expressing cells showed less injury, resulting in 20-30% of LDH release. Astrocytes expressing E6, E7, LXSN and mock-infected cells showed a typical apoptotic death pattern on the DNA gel after treatment with a low-dose of H2O2 (10 micromole), however they died from necrotic death after a high-dose (200 micromole) H2O2. Overexpression of HPV-E7 genes protected the cells from apoptotic death after a low-dose of H2O2 and from necrotic death after a high-dose of H2O2, while the overexpression of E6 genes from the necrotic death. E7 expressing astrocytes showed higher catalase activity and the levels of E2F protein surged more than 100-folds compared with the control astrocytes. We believe that the activity of E7 protein to protect astrocytes from H2O2 injury was at least partly due to increased catalase, a scavenger protein.

Selective and biphasic effect of the membrane lipid peroxidation product 4-hydroxy-2,3-nonenal on N-methyl-D-aspartate channels

Increased oxyradical production and membrane lipid peroxidation occur in neurons under physiological conditions and in neurodegenerative disorders. Lipid peroxidation can alter synaptic plasticity and may increase the vulnerability of neurons to excitotoxicity, but the underlying mechanisms are unknown. We report that 4-hydroxy-2,3-nonenal (4HN), an aldehyde product of lipid peroxidation, exerts a biphasic effect on NMDA-induced current in cultured rat hippocampal neurons with current being increased during the first 2 h and decreased after 6 h. Similarly, 4HN causes an early increase and a delayed decrease in NMDA-induced elevation of intracellular Ca2+ levels. In contrast, 4HN affects neither the ion current nor the Ca2+ response to alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA). The initial enhancement of NMDA-induced current is associated with increased phosphorylation of the NR1 receptor subunit, whereas the delayed suppression of current is associated with cellular ATP depletion and mitochondrial membrane depolarization. Cell death induced by 4HN is attenuated by an NMDA receptor antagonist, but not by an AMPA receptor antagonist. A secreted form of amyloid precursor protein, previously shown to protect neurons against oxidative and excitotoxic insults, prevented each of the effects of 4HN including the early and late changes in NMDA current, delayed ATP depletion, and cell death. These findings show that the membrane lipid peroxidation product 4HN can modulate NMDA channel activity, suggesting a role for this aldehyde in physiological and pathophysiological responses of neurons to oxidative stress.

The kinetics of catalytic incineration of C2H5SH and (CH3)2S2 over a Pt/Al2O3 catalyst

Catalytic incineration is one of the cost-effective technologies to solve the troublesome VOCs. However, some sulfur containing VOCs, such as ethyl mercaptan and dimethyl disulfide, may deactivate the Pt catalyst that is commonly used in the catalytic incineration process. The catalytic incineration of these compounds over a Pt/Al2O3 catalyst was carried out in a bench scale catalytic incinerator. Three kinetic models, such as power-rate law, Mars and Van Krevelen model, and Langmuir-Hinshelwood model were used to analyze the results. A differential reactor design was used for best fit of kinetic models in this study. The results show that the Langmuir-Hinshelwood model is feasible to describe the catalytic incineration of both C2H5SH and (CH3)2S2. This suggests that the chemical adsorption of O2 molecule is important in the process of catalytic incineration of C2H5SH and (CH3)2S2.