Hydrophilic gold nanoclusters (Au NCs) whose physical and chemical properties are not susceptible to large changes in pH are greatly desired for diverse applications. Here, we design Au NCs protected ...by a hydroxyl-thiol ligand (e.g., 1-thioglycerol (TG)) with a molecular formula of Au
(TG)
as a proof-of-concept for a Au NC model with near-neutral surface charge. Unlike hydrophilic thiols with charged functional groups (e.g., carboxylate-thiol) that are usually used for hydrophilic Au NCs, this type of Au NCs is protected by hydroxyl-thiols, which are less susceptible to the prevailing pH conditions as the hydroxyl group is less acidic than water. More interestingly, the resulting Au NCs also possess pH-independent fluorescence intensity, making them suitable for applications under strong acidic conditions, which are currently not available in the reported hydrophilic Au NCs.
A method is proposed for determining the optimum penetration depth of prefabricated vertical drains (PVDs) in cases where vacuum consolidation is combined with the use of PVDs in a clayey deposit ...with two-way drainage. The advantages of combining vacuum pressure with embankment loading are discussed in terms of reducing preloading-induced lateral displacement of the subsoil, increasing the effective surcharge loading, and reducing construction time in the case of road construction. A vacuum consolidation project conducted in Saga, Japan, is described, and the results from a fully instrumented test section are presented and analyzed using a two-dimensional finite element approach. The numerical simulations compare well with the field measurements. The validated numerical approach is then used to examine the response of soft subsoil subjected to vacuum consolidation. The results confirm the usefulness of the proposed method for determining the optimum penetration depth of PVDs and the advantages of combining vacuum pressure with embankment loading.Key words: vacuum consolidation, preloading, prefabricated vertical drain, FEM analysis, embankment.
Abstract Background Advanced second- or third-degree heart block has been reported with variable incidence after surgery for congenital heart disease in children. We report the incidence of heart ...block requiring a pacemaker and describe the risk factors for this complication in a large multicenter study. Methods We performed a retrospective cohort study, using the Pediatric Health Information System database from 45 hospitals in the United States, for all children aged 18 years, discharged between January 1, 2004, and December 31, 2013, who underwent open surgery for congenital heart disease. Patients who had heart block and placement of a pacemaker during the same hospitalization were identified. Demographic characteristics, procedure and diagnostic codes, length of stay, and mortality were analyzed. Univariable and multivariable analyses were performed. Results There were 101,006 surgeries performed. The median age of patients was 0.5 years (interquartile range, 26 days to 3.2 years), and 1% of patients (n = 990) had heart block and placement of a pacemaker. Surgeries associated with the highest incidences of heart block and placement of a pacemaker included the double switch operation (15.6%), tricuspid valve (7.8%) and mitral valve (7.4%) replacement, atrial switch with ventricular septal defect repair (6.4%), and Rastelli operation (4.8%). On multivariable analysis, after controlling for surgical complexity, other comorbidities, age at surgery, admission year, and clustering by institution, patients with heart block and placement of a pacemaker had higher odds of mortality (odds ratio, 1.67; 95% confidence interval, 1.24-2.26; P < .001). Conclusions The incidence of postoperative heart block requiring permanent pacemaker placement immediately after congenital heart surgery is low (1%). However, these patients have higher mortality even after adjusting for heart surgery complexity.
The deformation characteristics of soil subjected to vacuum pressure are discussed and an approximate method is proposed for calculating settlement and lateral displacement of the ground induced by ...vacuum consolidation. Laboratory oedometer test results indicate that if the vacuum pressure alone is larger than the lateral stress required to maintain an at-rest (no horizontal strain) condition, there will be inward lateral displacement and the vacuum pressure will induce generally less settlement than a surcharge load of the same magnitude. In the case of field vacuum consolidation, the confining stress acting on a soil element can be regarded as consisting of two parts: Due to vacuum pressure and earth pressure. Assuming a value of the lateral earth pressure coefficient acting in the ground under vacuum consolidation
(
kao
)
, somewhere between the active and at-rest values, an equation defining the depth—below which there will be no significant inward lateral displacement—is derived. Further, assuming that the volumetric strain induced by vacuum consolidation is the same as the one-dimensional consolidation induced by application of a surcharge load of the same magnitude, an approximate method is proposed for calculating the ground settlement and inward lateral displacement induced by vacuum consolidation. This method has been applied to two case histories reported in the literature, and it is shown that the field-measured data are simulated reasonably well, suggesting that the method may be useful for the design of vacuum consolidation projects.
Highlights • κ opioid receptor activation induced significant conditioned place aversion in mice. • p38 MAPK activated in the amygdala after U50,488H pairing. • Intra-amygdala injection of SB203580 ...blocked U50,488H-induced conditioned place aversion.
Research to date suggests that second language acquisition results in functional and structural changes in the bilingual brain, however, in what way and how quickly these changes occur remains ...unclear. To address these questions, we studied fourteen English-speaking monolingual adults enrolled in a 12-week intensive French language-training program in Montreal. Using functional MRI, we investigated the neural changes associated with new language acquisition. The participants were scanned before the start of the immersion program and at the end of the 12 weeks. The fMRI scan aimed to investigate the brain regions recruited in a sentence reading task both in English, their first language (L1), and in French, their second language (L2). For the L1, fMRI patterns did not change from Time 1 to Time 2, while for the L2, the brain response changed between Time 1 and Time 2 in language-related areas. Of note, for the L2, there was higher activation at Time 2 compared to Time 1 in the left inferior parietal lobule (IPL) including the supramarginal gyrus. At Time 2 this higher activation in the IPL correlated with faster L2 reading speed. Moreover, higher activation in the left IPL at Time 1 predicted improvement in L2 reading speed from Time 1 to Time 2. Our results suggest that learning-induced plasticity occurred as early as 12 weeks into immersive second-language training, and that the IPL appears to play a special role in language learning.
•Brain changes are observed in adults after 12 weeks intensive language training.•The IPL has a key role in learning an L2.•Higher fMRI brain activation in the IPL after L2 training.•IPL activation before training predicts L2 learning success.•IPL activation after training related to proficiency in L2.
To reveal the influence of the number and location of joints on rock failure mechanism, using Particle Flow Code (PFC) to simulate the calculation of a large amount of acoustic emission data ...generated during breeding, development, and penetration of rock cracks, the fracture parameters such as the spatial location, rupture azimuth, rupture type, stress state, and moment magnitude of acoustic emission events in various fracture stages of multijoint rock were studied based on the moment tensor theory, the P-T diagram method, and the T-k diagram method. It will be of great importance in the geotechnical engineering field.
There is considerable variability in an individual's ability to acquire a second language (L2) during adulthood. Using resting-state fMRI data acquired before training in English speakers who ...underwent a 12 week intensive French immersion training course, we investigated whether individual differences in intrinsic resting-state functional connectivity relate to a person's ability to acquire an L2. We focused on two key aspects of language processing--lexical retrieval in spontaneous speech and reading speed--and computed whole-brain functional connectivity from two regions of interest in the language network, namely the left anterior insula/frontal operculum (AI/FO) and the visual word form area (VWFA). Connectivity between the left AI/FO and left posterior superior temporal gyrus (STG) and between the left AI/FO and dorsal anterior cingulate cortex correlated positively with improvement in L2 lexical retrieval in spontaneous speech. Connectivity between the VWFA and left mid-STG correlated positively with improvement in L2 reading speed. These findings are consistent with the different language functions subserved by subcomponents of the language network and suggest that the human capacity to learn an L2 can be predicted by an individual's intrinsic functional connectivity within the language network. Significance statement: There is considerable variability in second-language learning abilities during adulthood. We investigated whether individual differences in intrinsic functional connectivity in the adult brain relate to success in second-language learning, using resting-state functional magnetic resonance imaging in English speakers who underwent a 12 week intensive French immersion training course. We found that pretraining functional connectivity within two different language subnetworks correlated strongly with learning outcome in two different language skills: lexical retrieval in spontaneous speech and reading speed. Our results suggest that the human capacity to learn a second language can be predicted by an individual's intrinsic functional connectivity within the language network.
In this article, the fabrication methods of black silicon (b-Si), application and performance of b-Si in photovoltaics, and the theoretical modelling efforts in b-Si-based photovoltaic cells are ...reviewed. To date, the most popular fabrication methods are reactive ion etching and metal-assisted chemical etching, due to their flexibility and low cost. Other methods include laser irradiation, stain etching, electrochemical etching, and Fray–Farthing–Chen Cambridge process. Black silicon's largest application is in photovoltaics due to its absorption properties. Currently, the highest efficiency of b-Si-based solar cell reported in the literature is 22.1% with an interdigitated back contact configuration. Currently, the issue of high recombination rates due to the nanostructures is being actively researched on but has yet been fully resolved. There are only a few theoretical models of b-Si photovoltaics, with most focus on the optical properties. The optical performance is usually assessed based on Maxwell's equations, while the electrical properties are simulated based on semiconductor equations, including Poisson's, continuity and drift-diffusion current equations. Most studies neglect the effect of temperature. Modelling of the thermal properties of silicon nanostructures is performed with the Monte Carlo method to solve the phonon radiative transport equation for the temperature distribution.
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•Fabricated black silicon surfaces can achieve reflectance less than 5% in the visible light spectrum.•Black silicon solar cells achieve efficiencies higher than conventional cells.•The main challenge is to minimize recombination due to increased surface area.•Experimental data are available for certain configurations but need improvement.•Combined optical–electron–hole–phonon transport models are underdeveloped.
Healthcare workers (HCWs) are at increased risk of tuberculosis infection (TBI). We estimated the prevalence and incidence of TBI and risk factors among HCWs in Bangladeshi hospitals to target TB ...infection prevention and control (IPC) interventions. During 2013-2016, we conducted a longitudinal study among HCWs in four chest disease hospitals. At baseline, we administered a questionnaire on sociodemographic and occupational factors for TB, tuberculin skin tests (TST) in all hospitals, and QuantiFERON .sup.® -TB Gold in-Tube (QFT-GIT) tests in one hospital. We assessed factors associated with baseline TST positivity (induration greater than or equal to10mm), TST conversion (induration increase greater than or equal to10mm from baseline), baseline QFT-GIT positivity (interferon-gamma greater than or equal to0.35 IU/mL), and QFT-GIT conversion (interferon-gamma <0.35 IU/mL to greater than or equal to0.35 IU/mL). We included factors with a biologically plausible relationship with TBI identified in prior studies or having an association (p = <0.20) in the bivariate analyses with TST positivity or QFT-GIT positivity in multivariable generalized linear models. The Kaplan-Meier was used to estimate the cumulative TBI incidence rate per 100 person-years. Of the 758 HCWs invited, 732 (97%) consented to participate and 731 completed the one-step TST, 40% had a positive TST result, and 48% had a positive QFT-GIT result. In multivariable models, HCWs years of service 11-20 years had 2.1 (95% CI: 1.5-3.0) times higher odds of being TST-positive and 1.6 (95% CI 1.1-2.5) times higher odds of QFT-GIT-positivity at baseline compared with those working less than or equal to10 years. HCWs working 11-20 years in pulmonary TB ward had 2.0 (95% CI: 1.4-2.9) times higher odds of TST positivity, and those >20 years had 2.5 (95% CI: 1.3-4.9) times higher odds of QFT-GIT-positivity at baseline compared with those working <10 years. TBI incidence was 4.8/100 person-years by TST and 4.2/100 person-years by QFT-GIT. Females had 8.5 (95% CI: 1.5-49.5) times higher odds of TST conversion than males. Prevalent TST and QFT-GIT positivity was associated with an increased number of years working as a healthcare worker and in pulmonary TB wards. The incidence of TBI among HCWs suggests ongoing TB exposure in these facilities and an urgent need for improved TB IPC in chest disease hospitals in Bangladesh.
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