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OBJECTIVES/SPECIFIC AIMS: (1) Assess if the total duration of EEG suppression during a protocolized exposure to general anesthesia predicts cognitive performance in multiple cognitive domains immediately following emergence from anesthesia. (2) Assess if the total duration of EEG suppression in the same individuals predicts the rate of cognitive recovery in a three-hour period following emergence from anesthesia. METHODS/STUDY POPULATION: This was a non-specified substudy of NCT01911195, a multicenter investigation taking place at the University of Michigan, University of Pennsylvania, and Washington University in St. Louis. 30 healthy volunteers aged 20-40 years were recruited to receive general anesthesia. Participants in the anesthesia arm were anesthetized for three hours at isoflurane levels compatible with surgery (1.3 MAC). Multichannel sensor nets were used for EEG acquisition during the anesthetic exposure. EEG suppression was detected through automated voltage-thresholded classification of 2-second signal epochs, with concordance assessed across sensors. Following return of responsiveness to verbal commands, participants completed up to three hours of serial cognitive tests assessing executive function, reaction time, cognitive throughput, and working memory. Non-linear mixed effects models will be used to estimate the initial cognitive deficit and the rate of cognitive recovery following anesthetic exposure; these measures of cognitive function will be assessed in relation to total duration of suppression during anesthesia. RESULTS/ANTICIPATED RESULTS: Participants displayed wide variability in the total amount of suppression during anesthesia, with a median of 31.2 minutes and range from 0 minutes to 115.2 minutes. Initial analyses suggest that greater duration of burst suppression had a weak relationship with participants’ initial cognitive deficits upon return of responsiveness from anesthesia. Model generation of rate of recovery following anesthetic exposure is pending, but we anticipate this will also have a weak relationship with burst suppression. DISCUSSION/SIGNIFICANCE OF IMPACT: In healthy adults receiving a standardized exposure to anesthesia without surgery, burst suppression appears to be a poor predictor of post-anesthesia cognitive task performance. This suggests that burst suppression may have limited utility as a predictive marker of post-operative cognitive functioning, particularly in young adults without significant illness.
The current transient was studied on AlGaN/GaN HEMTs for RF power amplifiers under different temperatures. The current transient measurements include two different approaches. One is to measure the current transient from off-state (without bias) to a quiescent point (Q-point). Different transient behaviors were observed while switching to different Q-points. Another one is to measure the current transient from different currents to the Q-point of VDS = 28 V and ID = 100 mA/mm. The different currents before switching to Q-point of VDS = 28 V and ID = 100 mA/mm show the different transient characteristics. Most of the current transient demonstrates temperature independence in this study.
The piezophotonic effect is the coupling between piezoelectric properties and photoexcitation, where strain-induced piezopotential modulates and controls the relevant optical process. Specifically, metal ions as activators are capable of responding to photoexcitation and subsequent emission of light, also called mechanoluminescence, in general, and piezoluminescence specifically for piezoelectrics. These phenomena are helpful for understanding the materials fundamentals and conceiving widespread device applications. In this article, we briefly introduce the physical mechanisms of piezophotonics, including piezoluminescence. Selected host materials and metal-ion activators are described for demonstrating the piezophotonic effect. We provide a unified profile and recent prototypical demonstrations of light emission triggered by mechanical stimuli. The devices based on these materials offer the advantages of remote detection, nondestructive analysis, and repeatability, hence they are promising candidates for applications in stress sensing, structural health diagnosis, three-dimensional handwriting, magnetic-optical sensing, energy harvesting, biomedicine, novel light sources, and displays.
Vertically aligned nitrogen-doped nanocrystalline diamond nanorods are fabricated from nitrogen-doped nanocrystalline diamond films using reactive ion etching in oxygen plasma. These nanorods show enhanced thermionic electron emission (TEE) characteristics, viz., a high current density of 12.0 mA/cm2 and a work function value of 4.5 eV with an applied voltage of 3 V at 923 K. The enhanced TEE characteristics of these nanorods are ascribed to the induction of nanographitic phases at the grain boundaries and the field penetration effect through the local field enhancement from nanorods owing to a high aspect ratio and an excellent field enhancement factor.
To determine the prevalence of Cryptosporidium in dairy cattle in Guangdong Province, South China, 1440 fecal samples were collected from 10 farms and screened for Cryptosporidium with PCR. The overall prevalence of Cryptosporidium was 4.38% (63/1440), and the infection rates in preweaned calves, postweaned calves, heifers and adults were 6.4% (19/297), 6.19% (33/533), 1.48% (4/271) and 2.06% (7/339), respectively. Three Cryptosporidium species, Cryptosporidium andersoni (n = 33), Cryptosporidium bovis (n = 22) and Cryptosporidium ryanae (n = 8) were detected by DNA sequence analysis of the 63 positive samples, and C. andersoni was identified as the most common species on the dairy cattle farms. In preweaned calves, C. bovis was the most prevalent species (9/19, 47.4%). In contrast, C. andersoni was the predominant species (19/33, 57.6%) in postweaned calves and the only species found in heifers and adults. The zoonotic species Cryptosporidium parvum was not detected in this study. Twenty-four C. andersoni isolates were successfully classified into three multilocus sequence typing (MLST) subtypes. MLST subtype A4,A4,A4,A1 was the predominant subtype, and MLST subtype A2,A5,A2,A1, previously found in sheep, was detected in cattle for the first time. A linkage disequilibrium analysis showed that the C. andersoni isolates had a clonal genetic population structure. However, further molecular studies are required to better understand the epidemiology of Cryptosporidium in Guangdong.
In this study, AlGaN/GaN high electron mobility transistors (HEMTs) with a two-dimensional hole gas (2DHG) were investigated. In addition to a two-dimensional electron gas (2DEG) formed at the interface of the AlGaN and GaN layers for being a channel, a 2DHG was designed and formed underneath the channel to be the back gate. The simulated results showed the operation of device can be depletion-mode and enhancement-mode by adjusting the back gate bias. The fabricated devices showed the feasibility of 2DHG back gate control.
Previous studies have indicated that there is dopamine transporter (DAT) dysregulation and P300 abnormality in adults with attention-deficit hyperactivity disorder (ADHD); however, the correlations among the three have not been fully explored.
A total of 11 adults (9 males and 2 females) with ADHD and 11 age-, sex-, and education-level-matched controls were recruited. We explored differences in DAT availability using single-photon emission computed tomography and P300 wave of event-related potentials between the two groups. The correlation between DAT availability and P300 performance was also examined.
DAT availability in the basal ganglia, caudate nucleus, and putamen was significantly lower in the ADHD group. Adults with ADHD had lower auditory P300 amplitudes at the Pz and Cz sites, as well as longer Fz latency than controls. DAT availability was negatively correlated to P300 latency at Pz and Fz.
Adults with ADHD had both abnormal DAT availability and P300 amplitude, suggesting that ADHD is linked to dysfunction of the central dopaminergic system and poor cognitive processes related to response selection and execution.
Burt and Burzynska (2017) have produced a very significant and innovative study on social networks among Chinese entrepreneurs. As the authors claim, this may be an exceptional dataset with certain unique features. It is a comparative study between Chinese and American entrepreneurs. While the American data is rather limited in scope, it does provide valuable theoretical and measurement information by which to examine possible similarities and differences of the private enterprises and entrepreneurs in these two societies. Second, it examines two general network principles, namely the association between brokerage and success, and between closure and trust. In general, the study affirms comparable results in the two societies, though somewhat different measurements require cautious interpretation. Third, the authors explore two innovative notions worthy of our attention. They employ events as the frames on which social ties (contacts) were generated (Table A1). This turns out to be very fruitful. For example, the founding event provided interesting social network information, more so than current and other events. The event-name generators reveal the time-related dynamics of network stability and changes, and alert us to possible underestimation of network effects if only the current event or the present time is examined. Finally, the authors attempt possible network measures for the notion of guanxi. This exploration sets the initial stage for more rigorous measures of guanxi in future studies of entrepreneurs in China and other societies.
During 1997–2012 we conducted a nationwide camera-trapping survey and assessed the availability of prey and habitat for the clouded leopard Neofelis nebulosa in Taiwan. We surveyed 1,249 camera-trap sites over 113,636 camera-trap days, from the seashore to an altitude of 3,796 m and covering various types of vegetation. No clouded leopards were photographed during 128,394 camera-trap days, including at 209 sites in other studies, confirming the presumed extinction of clouded leopards in Taiwan. Assessment of the prey base revealed altitudinal distribution patterns of prey species and prey biomass. Areas at lower altitudes and with less human encroachment and hunting supported a higher prey biomass and more of the typical prey species of clouded leopards. Habitat analysis revealed 8,523 km2 of suitable habitat but this was reduced to 6,734 km2 when adjacent areas of human encroachment were subtracted. In the absence of hunting and large mammalian carnivores the major prey of clouded leopards in Taiwan, such as Formosan macaques Macaca cyclopis, Reeves's muntjacs Muntiacus reevesi, Formosan serow Capricornis swinhoei and sambar Rusa unicolor, could become over-abundant. Thus, it is important to address the cascading effect of the disappearance of top-down predator control. Our assessment indicated that, with proper regulation of hunting, habitat restoration and corridor improvement, it may be possible to reintroduce the clouded leopard.
Diamond films with good electron emission properties show great potential for applications such as electron sources. For single-crystalline diamond, the negative electron affinity at hydrogen-terminated surfaces enables efficient emission of conduction electrons into vacuum. Although electrons are not naturally present in the diamond conduction band, p–n junction diode structures make this possible; electrons are injected from n-type diamond to the conduction band of p-type diamond, giving rise to electron emission with efficiencies exceeding 1%. Alternatively, impacting electron beams can be used to inject “secondary” electrons into the conduction band, resulting in high emission gain. For ultrananocrystalline diamond (UNCD) films with versatile granular structure, enhanced electron field emission (EFE) properties can be achieved by altering the granular structure of the films. Utilization of nanoscale tips as templates for growing UNCD film or direct reactive ion etching of the film further enhances their EFE behavior. On the other hand, the release of electrons through application of thermal energy can be utilized in a thermionic energy converter to directly transform heat into electricity. With the addition of ion current from doped diamond emitters to the thermionic electron current, power output enhancement of the converter can be realized.
Meningiomas account for approximately 24-30% of primary intracranial neoplasms. Histopathologic grade and degree of resection are two major prognostic factors. The aim of this study was to determine the factors associated with the prognosis of meningioma.
We used immunohistochemistry to analyze the expression levels of Vav3, SPARC, p-Akt, cyclin D1, and Ki-67 in 287 meningiomas of all grades.
The expression of Vav3, SPARC, p-Akt, cyclin D1, and Ki- 67 significantly increased with meningioma grade (p<0.01), and was higher in brain-invasive meningiomas compared to non-invasive meningiomas (WHO grade I) (p<0.05). Furthermore, the expression of Vav3, p-Akt, and Ki-67 was higher in recurrent meningiomas compared to non-recurrent meningiomas (WHO grade I) (p<0.05).
The expression of Vav3, SPARC, p-Akt, cyclin D1, and Ki-67 in meningiomas appears to correlate with meningioma invasiveness, aggressiveness, and recurrence.
To assess the relative validity and reproducibility of the quantitative FFQ used in the Tzu Chi Health Study (TCHS).
The reproducibility was evaluated by comparing the baseline FFQ with the 2-year follow-up FFQ. The validity was evaluated by comparing the baseline FFQ with 3 d dietary records and biomarkers (serum folate and vitamin B12). Median comparison, cross-classification and Spearman correlation with and without energy adjustment and deattenuation for day-to-day variation were assessed.
TCHS is a prospective cohort containing a high proportion of true vegetarians and part-time vegetarians (regularly consuming a vegetarian diet without completely avoiding meat).
Subsets of 103, seventy-eight and 1528 TCHS participants were included in the reproducibility, dietary record-validity and biomarker-validity studies, respectively.
Correlations assessing the reproducibility for repeat administrations of the FFQ were in the range of 0·46–0·65 for macronutrients and 0·35–0·67 for micronutrients; the average same quartile agreement was 40%. The correlation between FFQ and biomarkers was 0·41 for both vitamin B12 and folate. Moderate to good correlations between the baseline FFQ and dietary records were found for energy, protein, carbohydrate, saturated and monounsaturated fat, fibre, vitamin C, vitamin A, K, Ca, Mg, P, Fe and Zn (average crude correlation: 0·47 (range: 0·37–0·66); average energy-adjusted correlation: 0·43 (range: 0·38–0·55); average energy-adjusted deattenuated correlation: 0·50 (range: 0·44–0·66)) with same quartile agreement rate of 39% (range: 35–45%), while misclassification to the extreme quartile was rare (average: 4% (range: 0–6%)).
The FFQ is a reliable and valid tool to rank relative intake of major nutrients for TCHS participants.
This paper details the development of a technique to improve the minority carrier lifetime of 4H-SiC thick (≥ 100 μm) n-type epitaxial layers through multiple thermal oxidations. A steady improvement in lifetime is seen with each oxidation step, improving from a starting ambipolar carrier lifetime of 1.09 µs to 11.2 µs after 4 oxidation steps and a high-temperature anneal. This multiple-oxidation lifetime enhancement technique is compared to a single high-temperature oxidation step, and a carbon implantation followed by a high-temperature anneal, which are traditional ways to achieve high ambipolar lifetime in 4H-SiC n-type epilayers. The multiple oxidation treatment resulted in a high minimum carrier lifetime of 6 µs, compared to < 2 µs for other treatments. The implications of lifetime enhancement to high-voltage/high-current 4H-SiC power devices are also discussed.
III-V compounds such as InGaAs, InAs, InSb have great potential for future low power high speed devices (such as MOSFETs, QWFETs, TFETs and NWFETs) application due to their high carrier mobility and drift velocity. The development of good quality high k gate oxide as well as high k/III-V interfaces is prerequisite to realize high performance working devices. Besides, the downscaling of the gate oxide into sub-nanometer while maintaining appropriate low gate leakage current is also needed. The lack of high quality III-V native oxides has obstructed the development of implementing III-V based devices on Si template. In this presentation, we will discuss our efforts to improve high k/III-V interfaces as well as high k oxide quality by using chemical cleaning methods including chemical solutions, precursors and high temperature gas treatments. The electrical properties of high k/InSb, InGaAs, InSb structures and their dependence on the thermal processes are also discussed. Finally, we will present the downscaling of the gate oxide into sub-nanometer scale while maintaining low leakage current and a good high k/III-V interface quality.
Quaternary semiconductors, Cu2ZnSnS4 and Cu2ZnSnSe4 which contain only earth-abundant elements, have been considered as the alternative absorber layers to Cu(In,Ga)Se2 (CIGS) for thin film solar cells although CIGS-based solar cells have achieved efficiencies over 20 %. In this work we report an air-stable route for preparation of Cu2ZnSn(Sx,Se(1-x))4 (CZTSSe) thin film absorbers by a solution process based on the binary and ternary chalcogenide nanoparticle precursors dispersed in organic solvents. The CZTSSe absorber layers were achieved by spin coating of the ink precursors followed by annealing under Ar/Se atmosphere at temperature up to 580°C. We have investigated the influence of the annealing temperature on the reduction or elimination of detrimental secondary phases. X-ray diffraction combined with Raman spectroscopy was utilized to better identify the secondary phases existing in the absorber layers. Solar cells were completed by chemical bath deposited CdS buffer layer followed by sputtered i-ZnO/ZnO: Al bi-layers and evaporated Ni/Al grids.
While China continues to develop capitalistic capacities, the party-state has increasingly tightened control of the economy and synchronized political and economic stratification – a tendency towards a centrally managed capitalism. Under centrally managed capitalism, the party-state commands the economy by controlling personnel, organizations, and capital in both political and economic arenas. At the same time, it delegates fiscal and administrative authorities to multiple and diversely formed corporations to compete in the marketplace. I further speculate on future ideological alternatives: a western-style democracy, a mature-stage socialism, or an enlightened authoritarianism – Xiaokang (小康 moderate prosperity or well-off society). After eliminating or casting doubt on the former two, I argue that a two-step transformation towards Xiaokang is under way. In the first step, the party-state leadership gradually decouples its position from Marxist ideology of communism and socialism, and moves towards the maintenance of economic growth and social order. The second step then allows the legitimacy of party rule to be based on indigenous Confucian ideology that emphasizes enlightened leaders, moral institutions, and social relations (i.e., Xiaokang). Finally, I explore the feasibility and paths towards an indigenous ideology of democracy (Datong: 大同 – universal harmony).
It is known that levels of brain natriuretic peptide predict outcomes of treatment for adults with decompensated heart failure. We hypothesized that it could predict outcomes in children with this condition.
We divided retrospectively 82 patients with serial measurements of brain natriuretic peptide into 3 groups: those who survived and did not need readmission within less than 60 days; those who survived but needed readmission within less than 60 days; and those who died in hospital or within less than 60 days. Initial and final levels of the peptide correlated with adverse outcomes.
The percent change in level of the peptide was minus 78 percent, minus 38 percent, and 138 percent in the readmission-free group, the readmitted, and nonsurviving groups, respectively. Final levels were significantly lower in the readmission-free group than in the readmitted and nonsurviving groups (p equals 0.013 and p is less than 0.00001, respectively) and in the readmitted group than in the nonsurvivors (p equals 0.013). On univariate analysis, the final level, the change in level, and the percentage change in level significantly predicted outcomes (p equals 0.0002, 0.0072 and 0.0005, respectively). On multivariate analysis, only the final level of the peptide significantly predicted outcomes (p equals 0.01).
A final level of brain natriuretic peptide of greater than or equal to 760 picograms per millilitre strongly predicted an adverse outcome. Patients with higher final levels may be at higher risk of death and readmission, suggesting that this variable effectively predicts the response to treatment and prognosis in children with heart failure.