399 research outputs found
Charge carrier dynamics and reaction intermediates in heterogeneous photocatalysis by time-resolved spectroscopies
Sunlight as the most abundant renewable energy holds the promise to make our society sustainable. However, due to its low power density and intermittence, efficient conversion and storage of solar energy as a clean fuel are crucial. Apart from solar fuel synthesis, sunlight can also be used to drive other reactions including organic conversion and air/water purification. Given such potential of photocatalysis, the past few decades have seen a surge in the discovery of photocatalysts. However, the current photocatalytic efficiency is still very moderate. To address this challenge, it is important to understand fundamental factors that dominate the efficiency of a photocatalytic process to enable the rational design and development of photocatalytic systems. Many recent studies highlighted transient absorption spectroscopy (TAS) and time-resolved infrared (TRIR) spectroscopy as powerful approaches to characterise charge carrier dynamics and reaction pathways to elucidate the reasons behind low photocatalytic efficiencies, and to rationalise photocatalytic activities exhibited by closely related materials. Accordingly, as a fast-moving area, the past decade has witnessed an explosion in reports on charge carrier dynamics and reaction mechanisms on a wide range of photocatalytic materials. This critical review will discuss the application of TAS and TRIR in a wide range of heterogeneous photocatalytic systems, demonstrating the variety of ways in which these techniques can be used to understand the correlation between materials design, charge carrier behaviour, and photocatalytic activity. Finally, it provides a comprehensive outlook for potential developments in the area of time-resolved spectroscopies with an aim to provide design strategies for photocatalysts
Revisiting conditional accounting conservatism in state-controlled firms
This study explores the demand for conditional accounting conservatism from equity shareholders in state-controlled firms. An investigation of state-controlled firms listed on Hong Kong Stock Exchange from 1997 to 2013 shows that the extent of conditional conservatism in state-controlled firms increases when the leverage ratio decreases. It is also found that the high control rights held by the government in state-controlled firms are associated with high conditional conservatism. In addition, further analyses document an offsetting effect between high control rights and firm leverage; a reinforcing effect between high control rights and year of incorporation after 1992; and a substituting effect between high control rights and dividend payments. These findings suggest that the demand from equity shareholders, in addition to the debt demand, can be an important determinant of conditional conservatism and examination of these differing sources of demand can enhance the understanding on accounting conservatism in state-controlled firms
Molecular mechanisms regulating NMDA receptor trafficking
EThOS - Electronic Theses Online ServiceGBUnited Kingdo
An Eye on Clinical BERT: Investigating Language Model Generalization for Diabetic Eye Disease Phenotyping
Diabetic eye disease is a major cause of blindness worldwide. The ability to
monitor relevant clinical trajectories and detect lapses in care is critical to
managing the disease and preventing blindness. Alas, much of the information
necessary to support these goals is found only in the free text of the
electronic medical record. To fill this information gap, we introduce a system
for extracting evidence from clinical text of 19 clinical concepts related to
diabetic eye disease and inferring relevant attributes for each. In developing
this ophthalmology phenotyping system, we are also afforded a unique
opportunity to evaluate the effectiveness of clinical language models at
adapting to new clinical domains. Across multiple training paradigms, we find
that BERT language models pretrained on out-of-distribution clinical data offer
no significant improvement over BERT language models pretrained on non-clinical
data for our domain. Our study tempers recent claims that language models
pretrained on clinical data are necessary for clinical NLP tasks and highlights
the importance of not treating clinical language data as a single homogeneous
domain.Comment: Extended Abstract presented at Machine Learning for Health (ML4H)
symposium 2023, December 10th, 2023, New Orleans, United States, 24 page
Selective oxidation of methane to C2+ products over Au-CeO2 by photon-phonon co-driven catalysis.
Direct methane conversion to high-value chemicals under mild conditions is attractive yet challenging due to the inertness of methane and the high reactivity of valuable products. This work presents an efficient and selective strategy to achieve direct methane conversion through the oxidative coupling of methane over a visible-responsive Au-loaded CeO2 by photon-phonon co-driven catalysis. A record-high ethane yield of 755 μmol h−1 (15,100 μmol g−1 h−1) and selectivity of 93% are achieved under optimised reaction conditions, corresponding to an apparent quantum efficiency of 12% at 365 nm. Moreover, the high activity of the photocatalyst can be maintained for at least 120 h without noticeable decay. The pre-treatment of the catalyst at relatively high temperatures introduces oxygen vacancies, which improves oxygen adsorption and activation. Furthermore, Au, serving as a hole acceptor, facilitates charge separation, inhibits overoxidation and promotes the C-C coupling reaction. All these enhance photon efficiency and product yield
Health care seeking among detained undocumented migrants: a cross-sectional study
BACKGROUND: As in many European countries, access to care is decreased for undocumented migrants in the Netherlands due to legislation. Studies on the health of undocumented migrants in Europe are scarce and focus on care-seeking migrants. Not much is known on those who do not seek care. METHODS: This cross-sectional study includes both respondents who did and did not seek care, namely undocumented migrants who have been incarcerated in a detention centre while awaiting expulsion to their country of origin. A consecutive sample of all new arrivals was studied. Data were collected through structured interviews and reviews of medical records. RESULTS: Among the 224 male migrants who arrived at the detention centre between May and July 2008, 173 persons were interviewed. 122 respondents met inclusion criteria. Only half of the undocumented migrants in this study knew how to get access to medical care in the Netherlands if in need. Forty-six percent of respondents reported to have sought medical help during their stay in the Netherlands while having no health insurance (n = 57). Care was sought most frequently for injuries and dental problems. About 25% of these care seekers reported to have been denied care by a health care provider. Asian migrants were significantly less likely to seek care when compared to other ethnic groups, independent from age, chronic health problems and length of stay in the Netherlands. CONCLUSION: The study underlines the need for a better education of undocumented patients and providers concerning the opportunities for health care in the Netherlands. Moreover, there is a need to further clarify the reasons for the denial of care to undocumented patients, as well as the barriers to health care as perceived by undocumented migrants
Health effects of 12 weeks of team-sport training and fitness training in a community health centre for sedentary men with lifestyle diseases
This study compares the effects of team-sport training, for sedentary men with lifestyle diseases, with fitness training in a pragmatic set-up in a community health centre (CHC). Thirty-two men in the fitness group (FiG) and 36 men in the team-sport group (TsG) completed the training and trained for 60–90 min, two times/week for 12–16 weeks. In FiG and TsG, mean heart rate (HR) during training was 73.2% and 74.5% of HRmax, respectively. Percentage of training time above 90%HRmax was 6 ± 9% and 10 ± 15% and the percentage of participants who spent > 10% of total training time with HR > 90%HRmax was 20% and 41%, in FiG and TsG, respectively. In FiG, total fat mass was reduced by 3.5% (P<0.01), while performance in the 6 min walking test (6MWT) increased by 11% (P<0.001). In TsG, total fat mass was reduced by 2.2% (P<0.01), while 6MWT performance improved by 5% (P<0.05). Between-group differences were observed for systolic BP (P=0.041) and mean arterial pressure (P=0.050) in favour of TsG and for sit-to-stand test (P=0.031) in favour of FiG. In conclusion, small-sided team sport is a worthy alternative to fitness training since the overall health effects are comparable, for example, improved balance and reduced fat mass. Team sport elicits high heart rates and improves cardiovascular health by reducing blood pressure, while fitness training improves sit-to-stand test performance related to activity of daily living
Oakland Cemetery Comfort Station Buildings
This Historic Structure Report attempts to define the historical context and physical condition of the women\u27s and men\u27s comfort stations at Oakland Cemetery. The comfort stations were constructed in 1908, fifty-eight years after the opening of Oakland, in order to provide adequate public restroom facilities for the large crowds who visited the cemetery during its early history. A group effort has been made to research and document the history of the two comfort buildings, assess their current status, and make recommendations for treatment.https://scholarworks.gsu.edu/history_heritagepreservation/1053/thumbnail.jp
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Quantifying the Evolutionary Dynamics of Language
Human language is based on grammatical rules. Cultural evolution allows these rules to change over time. Rules compete with each other: as new rules rise to prominence, old ones die away. To quantify the dynamics of language evolution, we studied the regularization of English verbs over the past 1,200 years. Although an elaborate system of productive conjugations existed in English’s proto-Germanic ancestor, Modern English uses the dental suffix, ‘-ed’, to signify past tense. Here we describe the emergence of this linguistic rule amidst the evolutionary decay of its exceptions, known to us as irregular verbs. We have generated a data set of verbs whose conjugations have been evolving for more than a millennium, tracking inflectional changes to 177 Old-English irregular verbs. Of these irregular verbs, 145 remained irregular in Middle English and 98 are still irregular today. We study how the rate of regularization depends on the frequency of word usage. The half-life of an irregular verb scales as the square root of its usage frequency: a verb that is 100 times less frequent regularizes 10 times as fast. Our study provides a quantitative analysis of the regularization process by which ancestral forms gradually yield to an emerging linguistic rule.Human Evolutionary BiologyMathematic
Diptoindonesin G is a middle domain HSP90 modulator for cancer treatment
HSP90 inhibitors can target many oncoproteins simultaneously, but none have made it through clinical trials due to dose-limiting toxicity and induction of heat shock response, leading to clinical resistance. We identified diptoindonesin G (dip G) as an HSP90 modulator that can promote degradation of HSP90 clients by binding to the middle domain of HSP90 (
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