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- Ademuyiwa, Adesoji O., et al.
(author)
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Determinants of morbidity and mortality following emergency abdominal surgery in children in low-income and middle-income countries
- 2016
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In: BMJ Global Health. - : BMJ Publishing Group Ltd. - 2059-7908. ; 1:4
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Journal article (peer-reviewed)abstract
- Background: Child health is a key priority on the global health agenda, yet the provision of essential and emergency surgery in children is patchy in resource-poor regions. This study was aimed to determine the mortality risk for emergency abdominal paediatric surgery in low-income countries globally.Methods: Multicentre, international, prospective, cohort study. Self-selected surgical units performing emergency abdominal surgery submitted prespecified data for consecutive children aged <16 years during a 2-week period between July and December 2014. The United Nation's Human Development Index (HDI) was used to stratify countries. The main outcome measure was 30-day postoperative mortality, analysed by multilevel logistic regression.Results: This study included 1409 patients from 253 centres in 43 countries; 282 children were under 2 years of age. Among them, 265 (18.8%) were from low-HDI, 450 (31.9%) from middle-HDI and 694 (49.3%) from high-HDI countries. The most common operations performed were appendectomy, small bowel resection, pyloromyotomy and correction of intussusception. After adjustment for patient and hospital risk factors, child mortality at 30 days was significantly higher in low-HDI (adjusted OR 7.14 (95% CI 2.52 to 20.23), p<0.001) and middle-HDI (4.42 (1.44 to 13.56), p=0.009) countries compared with high-HDI countries, translating to 40 excess deaths per 1000 procedures performed.Conclusions: Adjusted mortality in children following emergency abdominal surgery may be as high as 7 times greater in low-HDI and middle-HDI countries compared with high-HDI countries. Effective provision of emergency essential surgery should be a key priority for global child health agendas.
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| 2. |
- Booker, Ian Don, et al.
(author)
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Oxidation-induced deep levels in n- and p-type 4H- and 6H-SiC and their influence on carrier lifetime
- 2016
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In: Physical Review Applied. - : American Physical Society. - 2331-7019. ; 6:1, s. 1-15
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Journal article (peer-reviewed)abstract
- We present a complete analysis of the electron- and hole-capture and -emission processes of the deep levels ON1, ON2a, and ON2b in 4H-SiC and their 6H-SiC counterparts OS1a and OS1b through OS3a and OS3b, which are produced by lifetime enhancement oxidation or implantation and annealing techniques. The modeling is based on a simultaneous numerical fitting of multiple high-resolution capacitance deep-level transient spectroscopy spectra measured with different filling-pulse lengths in n- and p-type material. All defects are found to be double-donor-type positive-U two-level defects with very small hole-capture cross sections, making them recombination centers of low efficiency, in accordance with minority-carrier-lifetime measurements. Their behavior as trapping and weak recombination centers, their large concentrations resulting from the lifetime enhancement oxidations, and their high thermal stability, however, make it advisable to minimize their presence in active regions of devices, for example, the base layer of bipolar junction transistors.
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| 3. |
- DInnocenzo, V., et al.
(author)
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Two-dimensional charge transport in molecularly ordered polymer field-effect transistors
- 2016
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In: JOURNAL OF MATERIALS CHEMISTRY C. - : ROYAL SOC CHEMISTRY. - 2050-7526 .- 2050-7534. ; 4:47, s. 11135-11142
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Journal article (peer-reviewed)abstract
- Nanometer-thick Langmuir-Schafer monolayers of an electron transporting polymer display charge transport, optical and electro-optical properties that do not depend on the number of layers deposited one above the other. This phenomenon can be rationalized with the micro-structure of the specific multi-layers, which introduces an interlayer hopping penalty confining transport to a neat 2D regime, with a channel not extending beyond a single similar to 3 nm thick polymer strand, as confirmed by kinetic Monte Carlo simulations. Such findings are critical to establish a quantitative structure-property nexus in high mobility polymer semiconductors and in the control of charge transport at a molecular scale.
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| 4. |
- Khalil, Ibrahim, et al.
(author)
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Burden of Diarrhea in the Eastern Mediterranean Region, 1990-2013 : Findings from the Global Burden of Disease Study 2013
- 2016
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In: American Journal of Tropical Medicine and Hygiene. - : American Society of Tropical Medicine and Hygiene. - 1476-1645 .- 0002-9637. ; 95:6, s. 1319-1329
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Journal article (peer-reviewed)abstract
- Diarrheal diseases (DD) are leading causes of disease burden, death, and disability, especially in children in low-income settings. DD can also impact a child's potential livelihood through stunted physical growth, cognitive impairment, and other sequelae. As part of the Global Burden of Disease Study, we estimated DD burden, and the burden attributable to specific risk factors and particular etiologies, in the Eastern Mediterranean Region (EMR) between 1990 and 2013. For both sexes and all ages, we calculated disability-adjusted life years (DALYs), which are the sum of years of life lost and years lived with disability. We estimate that over 125,000 deaths (3.6% of total deaths) were due to DD in the EMR in 2013, with a greater burden of DD in low- and middle-income countries. Diarrhea deaths per 100,000 children under 5 years of age ranged from one (95% uncertainty interval [UI] = 0-1) in Bahrain and Oman to 471 (95% UI = 245-763) in Somalia. The pattern for diarrhea DALYs among those under 5 years of age closely followed that for diarrheal deaths. DALYs per 100,000 ranged from 739 (95% UI = 520-989) in Syria to 40,869 (95% UI = 21,540-65,823) in Somalia. Our results highlighted a highly inequitable burden of DD in EMR, mainly driven by the lack of access to proper resources such as water and sanitation. Our findings will guide preventive and treatment interventions which are based on evidence and which follow the ultimate goal of reducing the DD burden.
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| 5. |
- Zuo, Guangzheng, et al.
(author)
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Impact of doping on the density of states and the mobility in organic semiconductors
- 2016
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In: PHYSICAL REVIEW B. - : AMER PHYSICAL SOC. - 2469-9950. ; 93:23, s. 235203-
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Journal article (peer-reviewed)abstract
- We experimentally investigated conductivity and mobility of poly(3-hexylthiophene) (P3HT) doped with tetrafluorotetracyanoquinodimethane (F(4)TCNQ) for various relative doping concentrations ranging from ultralow (10(-5)) to high (10(-1)) and various active layer thicknesses. Although the measured conductivity monotonously increases with increasing doping concentration, the mobilities decrease, in agreement with previously published work. Additionally, we developed a simple yet quantitative model to rationalize the results on basis of a modification of the density of states (DOS) by the Coulomb potentials of ionized dopants. The DOS was integrated in a three-dimensional (3D) hopping formalism in which parameters such as energetic disorder, intersite distance, energy level difference, and temperature were varied. We compared predictions of our model as well as those of a previously developed model to kinetic Monte Carlo (MC) modeling and found that only the former model accurately reproduces the mobility of MC modeling in a large part of the parameter space. Importantly, both our model and MC simulations are in good agreement with experiments; the crucial ingredient to both is the formation of a deep trap tail in the Gaussian DOS with increasing doping concentration.
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