Robust Binary Neural Network Operation from 233 K to 398 K via Gate Stack and Bias Optimization of Ferroelectric FinFET Synapses

A synergistic approach for optimizing devices, circuits, and neural network architectures was used to abate junction-temperature-change-induced performance degradation of a Fe-FinFET-based artificial neural network. We demonstrated that the digital nature of the binarized neural network, with the "0" state programmed deep in the subthreshold and the "1" state in strong inversion, is crucial for robust DNN inference. The performance of a purely software-based binary neural network (BNN), with 96.1% accuracy for Modified National Institute of Standards and Technology (MNIST) handwritten digit recognition, was used as a baseline. The Fe-FinFET-based BNN (including device-to-device variation at 300 K) achieved 95.7% inference accuracy on the MNIST dataset. Although substantial inference accuracy degradation with temperature change was observed in a nonbinary neural network, the BNN with optimized Fe-FinFETs as synaptic devices had excellent resistance to temperature change effects and maintained a minimum inference accuracy of 95.2% within a temperature range of -233K to 398K after gate stack and bias optimization. However, reprogramming to adjust device conductance was necessary for temperatures higher than 398K.Comment: Accepted to be published in IEEE ED

Hypermethylation of CCND2 May Reflect a Smoking-Induced Precancerous Change in the Lung

It remains unknown whether tobacco smoke induces DNA hypermethylation as an early event in carcinogenesis or as a late event, specific to overt cancer tissue. Using MethyLight assays, we analyzed 316 lung tissue samples from 151 cancer-free subjects (121 ever-smokers and 30 never-smokers) for hypermethylation of 19 genes previously observed to be hypermethylated in nonsmall cell lung cancers. Only APC (39%), CCND2 (21%), CDH1 (7%), and RARB (4%) were hypermethylated in >2% of these cancer-free subjects. CCND2 was hypermethylated more frequently in ever-smokers (26%) than in never-smokers (3%). CCND2 hypermethylation was also associated with increased age and upper lobe sample location. APC was frequently hypermethylated in both ever-smokers (41%) and never-smokers (30%). BVES, CDH13, CDKN2A (p16), CDKN2B, DAPK1, IGFBP3, IGSF4, KCNH5, KCNH8, MGMT, OPCML, PCSK6, RASSF1, RUNX, and TMS1 were rarely hypermethylated (<2%) in all subjects. Hypermethylation of CCND2 may reflect a smoking-induced precancerous change in the lung

Preparation and Characterization of New Nano-Composite Scaffolds Loaded With Vascular Stents

In this study, vascular stents were fabricated from poly (lactide-ɛ-caprolactone)/collagen/nano-hydroxyapatite (PLCL/Col/nHA) by electrospinning, and the surface morphology and breaking strength were observed or measured through scanning electron microscopy and tensile tests. The anti-clotting properties of stents were evaluated for anticoagulation surfaces modified by the electrostatic layer-by-layer self-assembly technique. In addition, nano-composite scaffolds of poly (lactic-co-glycolic acid)/polycaprolactone/nano-hydroxyapatite (PLGA/PCL/nHA) loaded with the vascular stents were prepared by thermoforming-particle leaching and their basic performance and osteogenesis were tested in vitro and in vivo. The results show that the PLCL/Col/nHA stents and PLGA/PCL/nHA nano-composite scaffolds had good surface structures, mechanical properties, biocompatibility and could guide bone regeneration. These may provide a new way to build vascularized-tissue engineered bone to repair large bone defects in bone tissue engineering

Global variation in diabetes diagnosis and prevalence based on fasting glucose and hemoglobin A1c

Fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) are both used to diagnose diabetes, but these measurements can identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening, had elevated FPG, HbA1c or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardized proportion of diabetes that was previously undiagnosed and detected in survey screening ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the age-standardized proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c was more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global shortfall in diabetes diagnosis and surveillance

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Global variation in diabetes diagnosis and prevalence based on fasting glucose and hemoglobin A1c

Fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) are both used to diagnose diabetes, but these measurements can identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening, had elevated FPG, HbA1c or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardized proportion of diabetes that was previously undiagnosed and detected in survey screening ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the age-standardized proportion who had elevated levels of both FPG and HbA1c was 29–39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c was more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global shortfall in diabetes diagnosis and surveillance

Global variations in diabetes mellitus based on fasting glucose and haemogloblin A1c

Fasting plasma glucose (FPG) and haemoglobin A1c (HbA1c) are both used to diagnose diabetes, but may identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening had elevated FPG, HbA1c, or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardised proportion of diabetes that was previously undiagnosed, and detected in survey screening, ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the agestandardised proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global gap in diabetes diagnosis and surveillance.peer-reviewe

The impact of impurities on the performance of cellulose triacetate membranes for CO2 separation

© 2018 Dr Hiep Thuan LuNatural gas and coal are the essential energy resources that will continue to occupy over 50% the global electricity market in the coming decades. The natural gas streams normally contain several components that require removal so that the fuel meets pipeline specifications. Membrane separation technology is an outstanding approach for gas processing with advantages in land footprint and energy efficiency. In particular, cellulose triacetate (CTA) membrane have been widely applied in natural gas processing for decades and remain the dominant material on the market share due to their competitive gas separation performance and acceptance by industry. However, the raw natural gas streams also contain several impurities that can negatively affect the performance of the CTA membrane unit. Although several studies on gas separation performance of CTA membrane have been conducted, the impact of impurities on the membrane performance is not fully understood. Cellulose triacetate membranes also have competitive CO2/N2 selectivity and are thus a prospective candidate for post-combustion carbon capture. However, studies on the impact of impurities in the flue gas, including liquid water of variable pH, sulphur oxides and nitrogen oxides, on the gas separation performance of CTA membrane are very limited. In this thesis, the impact of solutions of variable pH on CTA membranes was studied by exposing the dense membranes to solutions of pH 3, 7 and 13 solutions for up to 60 days. It was found that the membranes were relatively stable when exposed to water at pH 3 and pH 7 with a 30% increase in CO2 and N2 permeability and no loss in CO2/N2 selectivity. However, the membrane failed at pH 13 due to hydrolysis of the CTA polymer chains. Similarly, the membrane performance declined significantly when exposed to 0.74 kPa NOx at 22oC over a 120 day aging period. This was due to the reaction of trace NO2 in the gas mixture with the alcohol functional groups within the membrane structure. Interestingly, the CTA membrane was more selective for SO2 than CO2 and N2 and stable in 0.75 kPa SO2 at 22oC over a 100 day aging period. The results suggest that CTA is a viable membrane material for post-combustion capture if it can form into an ultrathin film to increase permeance. In natural gas processing, the performance of CTA membranes can also be affected by ethylene glycol, which can be entrained into the membrane separation unit from the upstream dehydration unit. In this thesis, the impact of two common ethylene glycols, monoethylene glycol and triethylene glycol, on the gas separation performance of CTA membranes was investigated. It was found that the glycols initially absorbed into the membrane reducing the permeation of He, CO2 and CH4 by a “pore-blocking” mechanism, but after a period of time, plasticised the membranes and enhanced the transport of CO2 and CH4. This plasticisation effect had less effect on He, which may be due to the lower solubility of He in these glycols which limited the transport of this gas through the swollen membrane structure. Interestingly, the membrane performance recovered when the glycols were removed from the polymer using a methanol wash. The findings highlighted the potential to recover the membrane performance when glycol flooding occurs in industrial plants. Hydrogen sulfide in the raw natural gas might also affect CTA membrane performance. This impurity is also of concern in pre-combustion carbon capture. To fulfil the gap of knowledge in the literature, this thesis studied the permeability of H2S across a range of partial pressures (up to 0.75 kPa) and temperature (22oC - 80oC). At 0.75 kPa H2S at 22oC, the CTA membrane showed stable CO2 permeability for up to 300 days which confirmed the long-term resistance of this material to the experimental H2S conditions. Other impurities that might challenge the performance of CTA membranes in natural gas processing and pre-combustion capture are condensable aromatic hydrocarbons. In this thesis, the performance of CTA membranes at 35oC in the presence of toluene and xylene with variable vapour activity was studied. At low CO2 partial pressure (0.75 bar), the permeation of CO2 and CH4 through the CTA membrane declined when adding toluene and xylene up to 0.5 vapour activity. However, the CTA membrane was plasticised when toluene vapour activity increased above 0.5 activity. A similar impact was not clearly observed in the case of high xylene vapour activity. At high CO2 pressure (7.5 bar), the membranes were plasticised by both hydrocarbons at 0.3 vapour activity. This finding demonstrated the co-operative effect of CO2 and condensable hydrocarbons on the CTA membrane. In addition, the sorption and permeability of toluene and xylene through the CTA membrane at vapour activity up to 0.8 at 35oC was also recorded. Overall, the thesis demonstrates that cellulose triacetate membrane is an outstanding material for CO2 separation in natural gas processing, pre- and post-combustion capture with high gas selectivity and resistance to most impurities in these industrial gas streams

Crosslinked PEG and PEBAX Membranes for Concurrent Permeation of Water and Carbon Dioxide

Membrane technology can be used for both post combustion carbon dioxide capture and acidic gas sweetening and dehydration of natural gas. These processes are especially suited for polymeric membranes with polyether functionality, because of the high affinity of this species for both H2O and CO2. Here, both crosslinked polyethylene glycol diacrylate and a polyether-polyamide block copolymer (PEBAX 2533©) are studied for their ability to separate CO2 from CH4 and N2 under single and mixed gas conditions, for both dry and wet feeds, as well as when 500 ppm H2S is present. The solubility of gases within these polymers is shown to be better correlated with the Lennard Jones well depth than with critical temperature. Under dry mixed gas conditions, CO2 permeability is reduced compared to the single gas measurement because of competitive sorption from CH4 or N2. However, selectivity for CO2 is retained in both polymers. The presence of water in the feed is observed to swell the PEG membrane resulting in a significant increase in CO2 permeability relative to the dry gas scenario. Importantly, the selectivity is again retained under wet feed gas conditions. The presence of H2S is observed to only slightly reduce CO2 permeability through both membranes