| 1. |
- Ademuyiwa, Adesoji O., et al.
(författare)
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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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Ingår i: BMJ Global Health. - : BMJ Publishing Group Ltd. - 2059-7908. ; 1:4
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Tidskriftsartikel (refereegranskat)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. |
- Thomas, HS, et al.
(författare)
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- 2019
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swepub:Mat__t
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| 3. |
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| 4. |
- Drake, TM, et al.
(författare)
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Surgical site infection after gastrointestinal surgery in children: an international, multicentre, prospective cohort study
- 2020
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Ingår i: BMJ global health. - : BMJ. - 2059-7908. ; 5:12
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Tidskriftsartikel (refereegranskat)abstract
- Surgical site infection (SSI) is one of the most common healthcare-associated infections (HAIs). However, there is a lack of data available about SSI in children worldwide, especially from low-income and middle-income countries. This study aimed to estimate the incidence of SSI in children and associations between SSI and morbidity across human development settings.MethodsA multicentre, international, prospective, validated cohort study of children aged under 16 years undergoing clean-contaminated, contaminated or dirty gastrointestinal surgery. Any hospital in the world providing paediatric surgery was eligible to contribute data between January and July 2016. The primary outcome was the incidence of SSI by 30 days. Relationships between explanatory variables and SSI were examined using multilevel logistic regression. Countries were stratified into high development, middle development and low development groups using the United Nations Human Development Index (HDI).ResultsOf 1159 children across 181 hospitals in 51 countries, 523 (45·1%) children were from high HDI, 397 (34·2%) from middle HDI and 239 (20·6%) from low HDI countries. The 30-day SSI rate was 6.3% (33/523) in high HDI, 12·8% (51/397) in middle HDI and 24·7% (59/239) in low HDI countries. SSI was associated with higher incidence of 30-day mortality, intervention, organ-space infection and other HAIs, with the highest rates seen in low HDI countries. Median length of stay in patients who had an SSI was longer (7.0 days), compared with 3.0 days in patients who did not have an SSI. Use of laparoscopy was associated with significantly lower SSI rates, even after accounting for HDI.ConclusionThe odds of SSI in children is nearly four times greater in low HDI compared with high HDI countries. Policies to reduce SSI should be prioritised as part of the wider global agenda.
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| 5. |
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| 6. |
- Abbafati, Cristiana, et al.
(författare)
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- 2020
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Tidskriftsartikel (refereegranskat)
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| 7. |
- Lozano, Rafael, et al.
(författare)
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Measuring progress from 1990 to 2017 and projecting attainment to 2030 of the health-related Sustainable Development Goals for 195 countries and territories: a systematic analysis for the Global Burden of Disease Study 2017
- 2018
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Ingår i: The Lancet. - : Elsevier. - 1474-547X .- 0140-6736. ; 392:10159, s. 2091-2138
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Tidskriftsartikel (refereegranskat)abstract
- Background: Efforts to establish the 2015 baseline and monitor early implementation of the UN Sustainable Development Goals (SDGs) highlight both great potential for and threats to improving health by 2030. To fully deliver on the SDG aim of “leaving no one behind”, it is increasingly important to examine the health-related SDGs beyond national-level estimates. As part of the Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017), we measured progress on 41 of 52 health-related SDG indicators and estimated the health-related SDG index for 195 countries and territories for the period 1990–2017, projected indicators to 2030, and analysed global attainment. Methods: We measured progress on 41 health-related SDG indicators from 1990 to 2017, an increase of four indicators since GBD 2016 (new indicators were health worker density, sexual violence by non-intimate partners, population census status, and prevalence of physical and sexual violence [reported separately]). We also improved the measurement of several previously reported indicators. We constructed national-level estimates and, for a subset of health-related SDGs, examined indicator-level differences by sex and Socio-demographic Index (SDI) quintile. We also did subnational assessments of performance for selected countries. To construct the health-related SDG index, we transformed the value for each indicator on a scale of 0–100, with 0 as the 2·5th percentile and 100 as the 97·5th percentile of 1000 draws calculated from 1990 to 2030, and took the geometric mean of the scaled indicators by target. To generate projections through 2030, we used a forecasting framework that drew estimates from the broader GBD study and used weighted averages of indicator-specific and country-specific annualised rates of change from 1990 to 2017 to inform future estimates. We assessed attainment of indicators with defined targets in two ways: first, using mean values projected for 2030, and then using the probability of attainment in 2030 calculated from 1000 draws. We also did a global attainment analysis of the feasibility of attaining SDG targets on the basis of past trends. Using 2015 global averages of indicators with defined SDG targets, we calculated the global annualised rates of change required from 2015 to 2030 to meet these targets, and then identified in what percentiles the required global annualised rates of change fell in the distribution of country-level rates of change from 1990 to 2015. We took the mean of these global percentile values across indicators and applied the past rate of change at this mean global percentile to all health-related SDG indicators, irrespective of target definition, to estimate the equivalent 2030 global average value and percentage change from 2015 to 2030 for each indicator. Findings: The global median health-related SDG index in 2017 was 59·4 (IQR 35·4–67·3), ranging from a low of 11·6 (95% uncertainty interval 9·6–14·0) to a high of 84·9 (83·1–86·7). SDG index values in countries assessed at the subnational level varied substantially, particularly in China and India, although scores in Japan and the UK were more homogeneous. Indicators also varied by SDI quintile and sex, with males having worse outcomes than females for non-communicable disease (NCD) mortality, alcohol use, and smoking, among others. Most countries were projected to have a higher health-related SDG index in 2030 than in 2017, while country-level probabilities of attainment by 2030 varied widely by indicator. Under-5 mortality, neonatal mortality, maternal mortality ratio, and malaria indicators had the most countries with at least 95% probability of target attainment. Other indicators, including NCD mortality and suicide mortality, had no countries projected to meet corresponding SDG targets on the basis of projected mean values for 2030 but showed some probability of attainment by 2030. For some indicators, including child malnutrition, several infectious diseases, and most violence measures, the annualised rates of change required to meet SDG targets far exceeded the pace of progress achieved by any country in the recent past. We found that applying the mean global annualised rate of change to indicators without defined targets would equate to about 19% and 22% reductions in global smoking and alcohol consumption, respectively; a 47% decline in adolescent birth rates; and a more than 85% increase in health worker density per 1000 population by 2030. Interpretation: The GBD study offers a unique, robust platform for monitoring the health-related SDGs across demographic and geographic dimensions. Our findings underscore the importance of increased collection and analysis of disaggregated data and highlight where more deliberate design or targeting of interventions could accelerate progress in attaining the SDGs. Current projections show that many health-related SDG indicators, NCDs, NCD-related risks, and violence-related indicators will require a concerted shift away from what might have driven past gains—curative interventions in the case of NCDs—towards multisectoral, prevention-oriented policy action and investments to achieve SDG aims. Notably, several targets, if they are to be met by 2030, demand a pace of progress that no country has achieved in the recent past. The future is fundamentally uncertain, and no model can fully predict what breakthroughs or events might alter the course of the SDGs. What is clear is that our actions—or inaction—today will ultimately dictate how close the world, collectively, can get to leaving no one behind by 2030.
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| 8. |
- Adel, Amany, et al.
(författare)
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Epidemiological and molecular analysis of circulating fowl adenoviruses and emerging of serotypes 1, 3, and 8b in Egypt
- 2021
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Ingår i: Heliyon. - : Elsevier. - 2405-8440. ; 7:12
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Tidskriftsartikel (refereegranskat)abstract
- Fowl adenoviruses (FAdVs) are a large group of viruses of different serotypes. They are responsible for inclusion body hepatitis, adenoviral gizzard erosion, and hepatitis hydropericardium syndrome. The present study presents a comprehensive overview of FAdVs in Egypt, with a focus on the epidemiological features of virus serotypes across the country. We conducted molecular investigation of multiple FAdV species based on the genetic signature of hypervariable regions 1-4 in the loop1 (L1) region of the hexon gene. Epidemiologically, the Nile Delta governorates showed high positivity of FAdVs, which were more commonly found in broilers than in layers. Genetically, species D and serotype 8a/E dominated, and the findings also revealed the emergence of new FAdV serotypes 1, 3, and 8b. The comparative analysis of hypervariable regions in the L1 region of the hexon gene revealed variables specific to each virus serotype. In silico predictions of L1 region revealed variations in the molecular structure and predicted the antigenic epitopes which may affect the cross-antigenicity between the different FAdV species and serotypes.
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| 9. |
- El-Sherif, Ahmed M., et al.
(författare)
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Resource utilization in management of spontaneous intracerebral hemorrhage without systemic risk factors : Does early surgical decompression matter?
- 2023
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Ingår i: Clinical neurology and neurosurgery. - : Elsevier. - 0303-8467 .- 1872-6968. ; 231
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Forskningsöversikt (refereegranskat)abstract
- Background: Even though different subtypes of spontaneous ICH are frequently linked to a poor prognosis, their causes, pathological features, and prognoses vary. Atypical intracerebral hemorrhage is the subtype of spontaneous ICH that usually occurs due to an underlying localized vascular lesion. It is unrelated to systemic vascular risk factors, mostly affects children and young adults and is associated with a relatively good outcome. This fact should be considered when planning the evaluation and treatment. Investigating the cause of this subtype is fundamental to providing optimal management. However, if resources do not allow completing the investigations, the cause will be more difficult to discover. Treatment decisions will be made under stress to save the patient's life, especially with rapidly deteriorating patients. Methods: We described three cases of spontaneous ICH without systemic risk factors where the bleeding source could not be determined before surgery due to a lack of resources, preventing preoperative vascular investigation. Knowing that the atypical ICH has a distinct identity, regarding etiology and prognosis, encouraged the surgeons to resort to early surgical decompression as an alternative plan. We reviewed the literature searching for supporting evidence. Results: The results of treatment of the presented cases were satisfactory. The lack of reported similar cases was brought to light by a literature analysis that sought to provide backing for the proposed management strategy. In the end, we supplied two graphic organizers to help readers remember the different types and treatment of hemorrhagic stroke. Conclusion: There isn't enough evidence to show that there are other ways to treat atypical intracerebral haemorrhage when resources are limited. The presented cases highlight the importance of decisionmaking in resource-constrained situations when patient outcomes can be improved.
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| 10. |
- Feigin, Valery L., et al.
(författare)
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Global, regional, and national burden of neurological disorders, 1990–2016 : a systematic analysis for the Global Burden of Disease Study 2016
- 2019
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Ingår i: Lancet Neurology. - : Elsevier. - 1474-4422 .- 1474-4465. ; 18:5, s. 459-480
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Tidskriftsartikel (refereegranskat)abstract
- Background: Neurological disorders are increasingly recognised as major causes of death and disability worldwide. The aim of this analysis from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2016 is to provide the most comprehensive and up-to-date estimates of the global, regional, and national burden from neurological disorders.Methods: We estimated prevalence, incidence, deaths, and disability-adjusted life-years (DALYs; the sum of years of life lost [YLLs] and years lived with disability [YLDs]) by age and sex for 15 neurological disorder categories (tetanus, meningitis, encephalitis, stroke, brain and other CNS cancers, traumatic brain injury, spinal cord injury, Alzheimer's disease and other dementias, Parkinson's disease, multiple sclerosis, motor neuron diseases, idiopathic epilepsy, migraine, tension-type headache, and a residual category for other less common neurological disorders) in 195 countries from 1990 to 2016. DisMod-MR 2.1, a Bayesian meta-regression tool, was the main method of estimation of prevalence and incidence, and the Cause of Death Ensemble model (CODEm) was used for mortality estimation. We quantified the contribution of 84 risks and combinations of risk to the disease estimates for the 15 neurological disorder categories using the GBD comparative risk assessment approach.Findings: Globally, in 2016, neurological disorders were the leading cause of DALYs (276 million [95% UI 247–308]) and second leading cause of deaths (9·0 million [8·8–9·4]). The absolute number of deaths and DALYs from all neurological disorders combined increased (deaths by 39% [34–44] and DALYs by 15% [9–21]) whereas their age-standardised rates decreased (deaths by 28% [26–30] and DALYs by 27% [24–31]) between 1990 and 2016. The only neurological disorders that had a decrease in rates and absolute numbers of deaths and DALYs were tetanus, meningitis, and encephalitis. The four largest contributors of neurological DALYs were stroke (42·2% [38·6–46·1]), migraine (16·3% [11·7–20·8]), Alzheimer's and other dementias (10·4% [9·0–12·1]), and meningitis (7·9% [6·6–10·4]). For the combined neurological disorders, age-standardised DALY rates were significantly higher in males than in females (male-to-female ratio 1·12 [1·05–1·20]), but migraine, multiple sclerosis, and tension-type headache were more common and caused more burden in females, with male-to-female ratios of less than 0·7. The 84 risks quantified in GBD explain less than 10% of neurological disorder DALY burdens, except stroke, for which 88·8% (86·5–90·9) of DALYs are attributable to risk factors, and to a lesser extent Alzheimer's disease and other dementias (22·3% [11·8–35·1] of DALYs are risk attributable) and idiopathic epilepsy (14·1% [10·8–17·5] of DALYs are risk attributable).Interpretation: Globally, the burden of neurological disorders, as measured by the absolute number of DALYs, continues to increase. As populations are growing and ageing, and the prevalence of major disabling neurological disorders steeply increases with age, governments will face increasing demand for treatment, rehabilitation, and support services for neurological disorders. The scarcity of established modifiable risks for most of the neurological burden demonstrates that new knowledge is required to develop effective prevention and treatment strategies.Funding: Bill & Melinda Gates Foundation.
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| 11. |
- Girgis, Adel S., et al.
(författare)
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Synthesis and DFT studies of an antitumor active spiro-oxindole
- 2015
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Ingår i: New Journal of Chemistry. - : Royal Society of Chemistry (RSC). - 1144-0546 .- 1369-9261. ; 39:10, s. 8017-8027
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Tidskriftsartikel (refereegranskat)abstract
- An anti-oncological active spiro-oxindole 7 was synthesized regioselectively via a [3+2]-cycloaddition reaction of azomethine ylide to exocyclic olefinic linkage of 4-piperidone 6, exhibiting properties against diverse tumor cell lines including leukemia, melanoma and cancers of the lung, colon, brain, ovary, breast, prostate, and kidney. Compound 7 crystallizes in the monoclinic system and P21/c space group with four molecules in the unit cell. The structure was also studied by AM1, PM3 and DFT techniques. DFT studies support the stereochemical selectivity of the reaction and determine the molecular electrostatic potential and frontier molecular orbitals.
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| 12. |
- Stanaway, Jeffrey D., et al.
(författare)
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Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990-2017: A systematic analysis for the Global Burden of Disease Study 2017
- 2018
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Ingår i: The Lancet. - 1474-547X .- 0140-6736. ; 392:10159, s. 1923-1994
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Tidskriftsartikel (refereegranskat)abstract
- Background The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 comparative risk assessment (CRA) is a comprehensive approach to risk factor quantification that offers a useful tool for synthesising evidence on risks and risk-outcome associations. With each annual GBD study, we update the GBD CRA to incorporate improved methods, new risks and risk-outcome pairs, and new data on risk exposure levels and risk- outcome associations. Methods We used the CRA framework developed for previous iterations of GBD to estimate levels and trends in exposure, attributable deaths, and attributable disability-adjusted life-years (DALYs), by age group, sex, year, and location for 84 behavioural, environmental and occupational, and metabolic risks or groups of risks from 1990 to 2017. This study included 476 risk-outcome pairs that met the GBD study criteria for convincing or probable evidence of causation. We extracted relative risk and exposure estimates from 46 749 randomised controlled trials, cohort studies, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. Using the counterfactual scenario of theoretical minimum risk exposure level (TMREL), we estimated the portion of deaths and DALYs that could be attributed to a given risk. We explored the relationship between development and risk exposure by modelling the relationship between the Socio-demographic Index (SDI) and risk-weighted exposure prevalence and estimated expected levels of exposure and risk-attributable burden by SDI. Finally, we explored temporal changes in risk-attributable DALYs by decomposing those changes into six main component drivers of change as follows: (1) population growth; (2) changes in population age structures; (3) changes in exposure to environmental and occupational risks; (4) changes in exposure to behavioural risks; (5) changes in exposure to metabolic risks; and (6) changes due to all other factors, approximated as the risk-deleted death and DALY rates, where the risk-deleted rate is the rate that would be observed had we reduced the exposure levels to the TMREL for all risk factors included in GBD 2017.
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| 13. |
- Abdul-Jabbar, Thealfaqar A., et al.
(författare)
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Efficient Battery Cell Balancing Methods for Low-Voltage Applications: A Review
- 2022
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Ingår i: 2022 IEEE International Conference in Power Engineering Application, ICPEA 2022 - Proceedings.
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Konferensbidrag (refereegranskat)abstract
- Battery balancing technologies are a crucial mech anism for the safe operation of electrochemical energy storage systems, such as lithium-ion batteries. Moreover, balancing be tween battery cells is essential for battery systems' life. Without any balancing circuitry, individual cell voltages can reach their maximum/minimum battery voltage limit faster than others, posing safety hazards. Furthermore, battery capacity reduction can occur when overcharging/over-discharging individual cells. So far, many balancing methodologies have been proposed and discussed in available literature. This paper presents a review of different state-of-The-Art cell balancing methods suitable for low voltage applications. The required control complexity, switch stress, balancing speed, cost and circuit size are considered as key aspects. Typically, cell bypass techniques, such as passive balancing, have the lowest cost and require no complex control strategies. In contrast, cell-To-cell balancing techniques can significantly increase the energy efficiency compared to cell bypass balancers, but these come with higher system costs and control complexity.
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| 14. |
- Abouhmad, Adel, et al.
(författare)
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Exploring the enzymatic and antibacterial activities of novel mycobacteriophage lysin b enzymes
- 2020
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 21:9
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Tidskriftsartikel (refereegranskat)abstract
- Mycobacteriophages possess different sets of lytic enzymes for disruption of the complex cell envelope of the mycobacteria host cells and release of the viral progeny. Lysin B (LysB) enzymes are mycolylarabinogalactan esterases that cleave the ester bond between the arabinogalactan and mycolic acids in the mycolylarabinogalactan-peptidoglycan (mAGP) complex in the cell envelope of mycobacteria. In the present study, four LysB enzymes were produced recombinantly and characterized with respect to their enzymatic and antibacterial activities. Examination of the kinetic parameters for the hydrolysis of para-nitrophenyl ester substrates, shows LysB-His6 enzymes to be active against a range of substrates (C4-C16), with a catalytic preference towards p-nitrophenyl laurate (C12). With p-nitrophenyl butyrate as substrate, LysB-His6 enzymes showed highest activity at 37◦C. LysB-His6 enzymes also hydrolyzed different Tween substrates with highest activity against Tween 20 and 80. Metal ions like Ca2+ and Mn2+ enhanced the enzymatic activity of LysB-His6 enzymes, while transition metal ions like Zn2+ and Cu2+ inhibited the enzymatic activity. The mycolylarabinogalactan esterase activity of LysB-His6 enzymes against mAGP complex was confirmed by LC-MS. LysB-His6 enzymes showed marginal antibacterial activity when tested alone against Mycobacterium smegmatis, however a synergetic activity was noticed when combined with outer membrane permealizers. These results confirm that LysB enzymes are lipolytic enzymes with potential application as antimycobacterials.
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| 15. |
- Abouzid, Mohamed, et al.
(författare)
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Investigating the current environmental situation in the Middle East and North Africa (MENA) region during the third wave of COVID-19 pandemic : urban vs. rural context
- 2022
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Ingår i: BMC Public Health. - : Springer Nature. - 1471-2458. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundCoronavirus 2019 (COVID-19) pandemic led to a massive global socio-economic tragedy that has impacted the ecosystem. This paper aims to contextualize urban and rural environmental situations during the COVID-19 pandemic in the Middle East and North Africa (MENA) Region.ResultsAn online survey was conducted, 6770 participants were included in the final analysis, and 64% were females. The majority of the participants were urban citizens (74%). Over 50% of the urban residents significantly (p < 0.001) reported a reduction in noise, gathering in tourist areas, and gathering in malls and restaurants. Concerning the pollutants, most urban and rural areas have reported an increase in masks thrown in streets (69.49% vs. 73.22%, resp.; p = 0.003). Plastic bags and hospital waste also increased significantly with the same p-value of < 0.001 in urban areas compared with rural ones. The multifactorial logistic model for urban resident predictors achieved acceptable discrimination (AUROC = 0.633) according to age, crowdedness, noise and few pollutants.ConclusionThe COVID-19 pandemic had a beneficial impact on the environment and at the same time, various challenges regarding plastic and medical wastes are rising which requires environmental interventions.
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| 16. |
- Adel, Amany, et al.
(författare)
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Genetic Variations among Different Variants of G1-like Avian Influenza H9N2 Viruses and Their Pathogenicity in Chickens
- 2022
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Ingår i: Viruses. - : MDPI AG. - 1999-4915. ; 14:5
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Tidskriftsartikel (refereegranskat)abstract
- Since it was first discovered, the low pathogenic avian influenza (LPAI) H9N2 subtype has established linages infecting the poultry population globally and has become one of the most prevalent influenza subtypes in domestic poultry. Several different variants and genotypes of LPAI H9N2 viruses have been reported in Egypt, but little is known about their pathogenicity and how they have evolved. In this study, four different Egyptian LPAI H9N2 viruses were genetically and antigenically characterized and compared to representative H9N2 viruses from G1 lineage. Furthermore, the pathogenicity of three genetically distinct Egyptian LPAI H9N2 viruses was assessed by experimental infection in chickens. Whole-genome sequencing revealed that the H9N2 virus of the Egy-2 G1-B lineage (pigeon-like) has become the dominant circulating H9N2 genotype in Egypt since 2016. Considerable variation in virus shedding at day 7 post-infections was detected in infected chickens, but no significant difference in pathogenicity was found between the infected groups. The rapid spread and emergence of new genotypes of the influenza viruses pinpoint the importance of continuous surveillance for the detection of novel reassortant viruses, as well as monitoring the viral evolution.
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| 17. |
- Alam, Aftab, et al.
(författare)
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Modeling the Inflammatory Response of Traumatic Brain Injury Using Human Induced Pluripotent Stem Cell Derived Microglia
- 2023
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert. - 0897-7151 .- 1557-9042. ; 40:19-20, s. 2164-2173
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Tidskriftsartikel (refereegranskat)abstract
- The neuroinflammatory response after traumatic brain injury (TBI) is implicated as a key mediator of secondary injury in both the acute and chronic periods after primary injury. Microglia are the key innate immune cell in the central nervous system, responding to injury with the release of cytokines and chemokines. In this context, we aimed to characterize the downstream cytokine response of human induced pluripotent stem cell (iPSC)-derived microglia when stimulated with five separate cytokines identified after human TBI. The iPSC-derived microglia were exposed to interleukin (IL)-1 & beta;, IL-4, IL-6, IL-10, and tumor necrosis factor (TNF) in the concentration ranges identified in clinical TBI studies. The downstream cytokine response was measured against a panel of 37 separate cytokines over a 72h time-course. The secretome revealed concentration-, time- and combined concentration and time-dependent downstream responses. TNF appeared to be the strongest inducer of downstream cytokine changes (51), followed by IL-1 & beta; (26) and IL-4 (19). IL-10 (11) and IL-6 (10) produced fewer responses. We also compare these responses with our previous studies of iPSC-derived neuronal and astrocyte cultures and the in vivo human TBI cytokine response. Notably, we found microglial culture to induce both a wider range of downstream cytokine responses and a greater fold change in concentration for those downstream responses, compared with astrocyte and neuronal cultures. In summary, we present a dataset for human microglial cytokine responses specific to the secretome found in the clinical context of TBI. This reductionist approach complements our previous datasets for astrocyte and neuronal responses and will provide a platform to enable future studies to unravel the complex neuroinflammatory network activated after TBI.
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| 18. |
- Almasalmeh, O, et al.
(författare)
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Soil erosion and sediment transport modelling using hydrological models and remote sensing techniques in Wadi Billi, Egypt
- 2021
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Ingår i: Modeling Earth Systems and Environment. - : Springer Science and Business Media LLC. - 2363-6203 .- 2363-6211. ; 8:1, s. 1215-1226
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Tidskriftsartikel (refereegranskat)abstract
- Modelling soil erosion and sediment transport are vital to assess the impact of the flash floods. However, limited research works have studied sediment transport, especially in Egypt. This paper employs the HEC-HMS lumped hydrological model to predict the sediment load due to the flood event of 9th March 2014 in Wadi Billi, Egypt. The Modified USLE model has been used to calculate the total upland erosion, while Laursen-Copeland has been used to simulate load streams' sediment transport potential. The Normalized Difference Vegetation Index (NDVI) has been applied over Landsat 8 image captured on 20th February 2014 using ArcMap 10.5 to determine the vegetation cover based on its spectral footprint. The resulted sedigraph showed accumulation of more than five thousand tons of sediments at the Wadi's outlet. The results are crucial to design a suitable stormwater management system to protect the downstream urban area and to use flood water for groundwater recharge.
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| 19. |
- Campion, James, 1989-, et al.
(författare)
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Toward Industrial Exploitation of THz Frequencies : Integration of SiGe MMICs in Silicon-Micromachined Waveguide Systems
- 2019
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Ingår i: IEEE Transactions on Terahertz Science and Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 2156-342X .- 2156-3446. ; 9:6, s. 624-636
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Tidskriftsartikel (refereegranskat)abstract
- A new integration concept for terahertz (THz) systems is presented in this article, wherein patterned silicon-on-insulator wafers form all DC, IF, and RF networks in a homogeneous medium, in contrast to existing solutions. Using this concept, silicon-micromachined waveguides are combined with silicon germanium (SiGe) monolithic microwave integrated circuits (MMICs) for the first time. All features of the integration platform lie in the waveguide’s H-plane. Heterogeneous integration of SiGe chips is achieved using a novel in-line H-plane transition. As an initial step toward complete systems, we outline the design, fabrication, and assembly of back-to-back transition structures, for use at D-band frequencies (110ï¿œ170 GHz). Special focus is given to the industrial compatibility of all components, fabrication, and assembly processes, with an eye on the future commercialization of THz systems. Prototype devices are assembled via two distinct processes, one of which utilizes semiautomated die-bonding tools. Positional and orientation tolerances for each process are quantified. An accuracy of $\pm \text3.5\; μ \textm$, $\pm \text1.5 °$ is achieved. Measured $S$-parameters for each device are presented. The insertion loss of a single-ended transition, largely due to MMIC substrate losses, is 4.2ï¿œ5.5 dB, with a bandwidth of 25 GHz (135ï¿œ160 GHz). Return loss is in excess of 5 dB. Measurements confirm the excellent repeatability of the fabrication and assembly processes and, thus, their suitability for use in high-volume applications. The proposed integration concept is highly scalable, permitting its usage far into the THz frequency spectrum. This article represents the first stage in the shift to highly compact, low-cost, volume-manufacturable THz waveguide systems.
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| 20. |
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| 21. |
- Elkorany, Ahmed Saad, et al.
(författare)
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Implementation of a Miniaturized Planar Tri-Band Microstrip Patch Antenna for Wireless Sensors in Mobile Applications
- 2022
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Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 22:2
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Tidskriftsartikel (refereegranskat)abstract
- Antennas in wireless sensor networks (WSNs) are characterized by the enhanced capacity of the network, longer range of transmission, better spatial reuse, and lower interference. In this paper, we propose a planar patch antenna for mobile communication applications operating at 1.8, 3.5, and 5.4 GHz. A planar microstrip patch antenna (MPA) consists of two F-shaped resonators that enable operations at 1.8 and 3.5 GHz while operation at 5.4 GHz is achieved when the patch is truncated from the middle. The proposed planar patch is printed on a low-cost FR-4 substrate that is 1.6 mm in thickness. The equivalent circuit model is also designed to validate the reflection coefficient of the proposed antenna with the S-11 obtained from the circuit model. It contains three RLC (resistor-inductor-capacitor) circuits for generating three frequency bands for the proposed antenna. Thereby, we obtained a good agreement between simulation and measurement results. The proposed antenna has an elliptically shaped radiation pattern at 1.8 and 3.5 GHz, while the broadside directional pattern is obtained at the 5.4 GHz frequency band. At 1.8, 3.5, and 5.4 GHz, the simulated peak realized gains of 2.34, 5.2, and 1.42 dB are obtained and compared to the experimental peak realized gains of 2.22, 5.18, and 1.38 dB at same frequencies. The results indicate that the proposed planar patch antenna can be utilized for mobile applications such as digital communication systems (DCS), worldwide interoperability for microwave access (WiMAX), and wireless local area networks (WLAN).
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| 22. |
- Hassona, Ahmed Adel, 1988, et al.
(författare)
-
A Low-loss D-band Chip-to-Waveguide Transition Using Unilateral Fin-line Structure
- 2018
-
Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. ; 2018-June, s. 390-393
-
Konferensbidrag (refereegranskat)abstract
- This paper presents a D-band interconnect realized using unilateral finline structure. The interconnect consists of a microstrip line implemented on a 75μm-thick SiC substrate. The line then couples to a unilateral finline taper that is mounted in the E-plane of a standard WR-6.5 D-band waveguide. The interconnect achieves low insertion loss and covers very wide frequency range. The measured minimum insertion loss is 0.67 dB and the maximum is 2 dB per transition across the entire D-band covering the frequency range 110-170 GHz. The transition does not require any galvanic contacts nor any special processing and can be implemented in any of the commercially available semiconductor technologies. This solution provides low-loss wideband packaging technique that enables millimeter-wave systems assembly using a high-performance simple approach.
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| 23. |
- Hassona, Ahmed Adel, 1988, et al.
(författare)
-
A non-galvanic D-band MMIC-to-waveguide transition using eWLB packaging technology
- 2017
-
Ingår i: 2017 IEEE MTT-S International Microwave Symposium (IMS). - : Institute of Electrical and Electronics Engineers (IEEE). - 0149-645X. - 9781509063604 ; , s. 510-512
-
Konferensbidrag (refereegranskat)abstract
- This paper presents a novel D-band interconnect implemented in a low-cost embedded Wafer Level Ball Grid Array (eWLB) commercial process. The non-galvanic transition is realized through a slot antenna directly radiating to a standard air filled waveguide. The interconnect achieves low insertion loss and relatively wide bandwidth. The measured average insertion loss is 3 dB across a bandwidth of 22% covering the frequency range 110138 GHz. The measured average return loss is -10 dB across the same frequency range. Adopting the low-cost eWLB process and standard waveguides makes the transition an attractive solution for interconnects beyond 100 GHz. This solution enables mm-wave system on chip (SoC) to be manufactured and assembled in high volumes cost effectively. To the authors' knowledge, this is first attempt to fabricate a packaging solution beyond 100 GHz using eWLB technology.
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| 24. |
- Hassona, Ahmed Adel, 1988, et al.
(författare)
-
Compact Low-Loss Chip-to-Waveguide and Chip-to-Chip Packaging Concept Using EBG Structures
- 2021
-
Ingår i: IEEE Microwave and Wireless Components Letters. - 1558-1764 .- 1531-1309. ; 31:1, s. 9-12
-
Tidskriftsartikel (refereegranskat)abstract
- This letter presents a novel approach for packaging millimeter-wave (mmW) and terahertz (THz) circuits. The proposed technique relies on using an on-chip coupling structure that couples the signal to a quarter-wavelength cavity, which in turn couples to either a waveguide (WG) or another chip. The solution also uses a periodic electromagnetic bandgap (EBG) structure that controls the electromagnetic wave and prevents field leakage in undesired directions. The proposed solution is fabricated and demonstrated at the D-band (110-170 GHz), and the measurement results show that it achieves a minimum insertion loss of 0.8 and a 3-dB bandwidth extending from 124 to 161 GHz. The proposed approach does not require any galvanic contacts and can be used for packaging integrated circuits in WG modules as well as for chip-to-chip communication.
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| 25. |
- Hassona, Ahmed Adel, 1988, et al.
(författare)
-
D-band waveguide-to-microstrip transition implemented in eWLB packaging technology
- 2020
-
Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 56:4, s. 187-
-
Tidskriftsartikel (refereegranskat)abstract
- This Letter presents a non-galvanic D-band (110-170 GHz) interconnect realised in embedded wafer level ball grid array (eWLB) packaging technology. The interconnect consists of a patch-radiator-based waveguide transition implemented using one of the technology's redistribution layers. The patch radiates to a WR-6.5 standard waveguide perpendicular to its plane. An electromagnetic band-gap structure realised by metal patches is used to suppress undesired modes and improve the performance of the transition. The proposed solution is experimentally verified, and measurement results show that the transition exhibits an average insertion loss of 2 dB across the frequency range 122-146 GHz which, to the best of the authors' knowledge, is the lowest reported loss for a D-band packaging solution in eWLB technology and hence addresses one of the main integration challenges facing millimetre-wave systems.
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| 26. |
- Hassona, Ahmed Adel, 1988, et al.
(författare)
-
D-band Waveguide Transition Based on Linearly Tapered Slot Antenna
- 2017
-
Ingår i: 2017 IMAPS Nordic Conference on Microelectronics Packaging (NordPac). - 9781538630556 ; , s. 64-67
-
Konferensbidrag (refereegranskat)abstract
- In this work, an on-chip Monolithic Microwave Integrated Circuit (MMIC) to waveguide transition is realized based on Linearly Tapered Slot antenna (LTSA) structure. The antenna is implemented on a 50-um-thick Gallium Arsenide (GaAs) substrate and placed in the E-plane of an air-filled D-band waveguide. The transition shows a maximum insertion loss of 1 dB across the frequency range 110-170 GHz. The average return loss of the transition is -15 dB and the minimum is -9 dB. The structure occupies an area of 0.82x0.6 mm2. The transition provides low-loss wide-band connectivity for millimeter-wave systems and addresses integration challenges facing systems operating beyond 100 GHz.
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| 27. |
- Hassona, Ahmed Adel, 1988, et al.
(författare)
-
Demonstration of +100-GHz Interconnects in eWLB Packaging Technology
- 2019
-
Ingår i: IEEE Transactions on Components, Packaging and Manufacturing Technology. - 2156-3985 .- 2156-3950. ; 9:7, s. 1406-1414
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents waveguide interconnects implemented in an embedded wafer level ball grid array (eWLB) packaging technology. The interconnects operate at D-band (110–170 GHz), hence are enabling the realization and commercialization of high-data-rate systems. The interconnects rely on implementing radiating structures on the technology’s redistribution layers instead of using conventional ball grid arrays for the transmission of the RF signal to/from the package. The interconnects interface with standard WR-6.5 waveguides. Moreover, they do not require any galvanic contacts with the waveguide. The interconnects achieve a measured insertion loss of 2.8 dB over a bandwidth of 33%. The adopted eWLB packaging technology is suitable for low-cost high-volume production and allows heterogeneous integration with other technologies. This paper proposes cost-effective high-performance interconnects for THz integration, thus addressing one of the main challenges facing systems operating beyond 100 GHz.
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| 28. |
- Hassona, Ahmed Adel, 1988
(författare)
-
Enabling Solutions for Integration and Interconnectivity in Millimeter-wave and Terahertz Systems
- 2020
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Recently, Terahertz (THz) systems have witnessed increasing attention due to the continuous need for high data rate transmission which is mainly driven by next-generation telecommunication and imaging systems. In that regard, the THz range emerged as a potential domain suitable for realizing such systems by providing a wide bandwidth capable of achieving and meeting the market requirements. However, the realization of such systems faces many challenges, one of which is interconnectivity and high level of integration. Conventional packaging techniques would not be suitable from performance perspective above 100 GHz and new approaches need to be developed. This thesis proposes and demonstrates several approaches to implement interconnects that operate above 100 GHz. One of the most attractive techniques discussed in this work is to implement on-chip coupling structures and insert the monolithic microwave integrated circuit (MMIC) directly into a waveguide (WG). Such approach provides high level of integration and eliminates the need of galvanic contacts; however, it suffers from a major drawback which isthe propagation of parasitic modes in the circuit cavity if the MMIC is large enough to allow such modes to propagate. To mitigate this problem, this work suggests and investigates the use of electromagnetic bandgap (EBG) structures that suppresses those modes such as bed of nails and mushroom-type EBG structures. The proposed techniques are used to implement several on-chip packaging solutions that have an insertion loss as low as 0.6 dB at D-band (110-170 GHz). Moreover, the solutions are demonstrated in several active systems using various commercial MMIC technologies. The thesis also investigates the possibility of utilizing the commercially available packaging technologies such as Embedded Wafer Level Ball Grid Array (eWLB) packaging. Such technology has been widely used for integrated circuits operating below 100 GHz but was not attempted in the THz range before. This work attempts to push the limits of the technology and proposes novel solutions based on coupling structures implemented in the technology’s redistribution layers. The proposed solutions achieve reasonable performance at D-band that are suitable for low-cost mass production while allowing heterogeneous integration with other technologies as well. This work addresses integration challenges facing systems operating in the THz range and proposes high-performance interconnectivity solutions demonstrated in a wide range of commercial technologies and hence enables such systems to reach their full potential and meet the increasing market demands.
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| 29. |
- Hassona, Ahmed Adel, 1988, et al.
(författare)
-
F-band Low-loss Tapered Slot Transition for Millimeter-wave System Packaging
- 2019
-
Ingår i: 2019 49th European Microwave Conference, EuMC 2019. - 9782874870552 ; , s. 432-435
-
Konferensbidrag (refereegranskat)abstract
- This work presents a packaging solution at F-band (90 - 140 GHz) using on-chip waveguide transition. The transition is realized using a Linearly Tapered Slot (LTS) implemented in a commercial Gallium Arsenide (GaAs) Monolithic Microwave Integrated Circuit (MMIC) technology. The LTS is mounted in the E-plane of a split-block waveguide module and fed through a microstrip line. The transition is experimentally verified using a back-to-back test structure and it exhibits an average insertion loss of 1.7 dB over the frequency range extending from 100 to 135 GHz. This work presents an on-chip packaging technique to realize the interface between MMICs and standard waveguides at millimeter-wave (mmW) frequencies and hence addressing one of the main integration challenging facing systems operating at that range.
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| 30. |
- Hassona, Ahmed Adel, 1988, et al.
(författare)
-
G-band Frequency Converters in 130-nm InP DHBT Technology
- 2021
-
Ingår i: 2020 50th European Microwave Conference, EuMC 2020. ; , s. 1027-1030
-
Konferensbidrag (refereegranskat)abstract
- This paper presents the design and characterisation of a two G-band (140 - 220 GHz) fundamental mixers. The mixers are implemented in a 130-nm indium phosphide (InP) double heterojunction bipolar transistor (DHBT) technology. First, a passive double balanced topology was investigated using a diode ring with balanced RF and LO ports. The mixer operates in both upconversion and downconversion modes. In order to reduce the power requirement on the local oscillator (LO) at G-band, the diodes were dc biased. Measurement results show that the mixer has an average conversion loss of 12.4 and 14 dB for upconversion and downconversion modes respectively and covers the frequency range extending from 180 to 194 GHz. The mixer exhibits an LO-RF isolation of 21 dB and requires an LO power of +2 dBm. An upconverting transconductance mixer topology was also investigated using the same technology. Measurement results show that the mixer has an average conversion gain of 1 dB over the frequency range of 171 to 220 GHz. The mixer operates as an upconverter and requires a low LO power of only -4 dBm.
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| 31. |
- Hassona, Ahmed Adel, 1988, et al.
(författare)
-
Low-cost D-band Waveguide Transition on LCP Substrate
- 2018
-
Ingår i: 48th European Microwave Conference (EuMC). - 9782874870514 ; , s. 1049-1052
-
Konferensbidrag (refereegranskat)abstract
- This work presents a waveguide transition based on a slot radiator implemented on liquid crystal polymer (LCP) substrate. The slot couples the RF signal to a D-band (110–170 GHz) waveguide perpendicular to its plane. The slot is fed using a microstrip line and can be bonded to any monolithic microwave integrated circuit (MMIC). A waveguide split-block that utilizes bed of nails structure is also presented. The structure is used to stop undesired radiation at the interface between the slot and the waveguide opening allowing better coupling between the slot and the waveguide by reducing radiation loss. The transition shows a minimum insertion loss of 2.1 dB and an average of 3.2 dB. The 3-dB bandwidth of the transition covers the frequency range 112 –140 GHz. Another variant of the transition is designed to cover the higher part of the band and shows an average insertion loss of 3.6 dB covering the frequency range 124–154 GHz. The transition presents a simple low-cost technique to interface between standard waveguides and MMICs in millimeter-waves systems.
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| 32. |
- Hassona, Ahmed Adel, 1988
(författare)
-
Non-galvanic Interconnects for Millimeter-wave Systems
- 2018
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Fueled by the increasing demand for higher data rates, millimeter-wave (mmW) systems emerged as a candidate that can provide multi-gigabit per second (Gb/s) transmission. This demand is mainly driven by modern communication systems and several other wireless and sensing applications such as production quality inspection and imaging systems. The full realization of such systems has been always challenged by the lack of low-loss low-cost interconnects and high-level integration. This challenge is more critical in systems operating beyond 100 GHz where conventional packaging techniques would not be suitable from performance perspective. D-band offers a wide spectrum ranging from 110 to 170 GHz and hence providing wide bandwidth that makes it suitable for high data rate systems. In this thesis, several interconnects that operate at D-band are presented. Different technologies were used to realize the interconnects. Two interconnects are realized in Embedded Wafer Level Ball Grid Array (eWLB) packaging technology. The technology has been widely used for low frequency applications. The proposed interconnects are based on slot antennas radiating to a standard air-filled waveguides. The interconnects achieve an average insertion loss of 3 dB and 3.4 dB across the frequency ranges 110-138 GHz and 116-151 GHz respectively. The proposed interconnects are generic and do not require any galvanic contacts. The utilized eWLB packaging technology is suitable for low-cost high-volume production and allows heterogeneous integration with other technologies as well. A chip-to-waveguide transition based on unilateral finline structure is also demonstrated. The interconnect consists of a microstrip line implemented on a 75 um-thick substrate. The line then couples to a unilateral finline taper that is mounted in the E-plane of a standard D-band waveguide. The transition achieves a very low loss of only 0.7 dB and covers a very wide band ranging from 110 to 170 GHz. A chip-to-waveguide transition in a commercial MMIC technology is also presented. The transition is based on Linearly Tapered Slot antenna (LTSA) structure. The antenna is implemented on a 50 um-thick Gallium Arsenide (GaAs) substrate. The transition exhibits an insertion loss of 1 dB across the frequency range 110-170 GHz. This work presents low-cost high-performance mmW interconnects and addresses integration challenges facing systems operating beyond 100 GHz paving the way for high-volume commercialization of such systems in the future.
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| 33. |
- Hassona, Ahmed Adel, 1988, et al.
(författare)
-
Nongalvanic Generic Packaging Solution Demonstrated in a Fully Integrated D-Band Receiver
- 2020
-
Ingår i: IEEE Transactions on Terahertz Science and Technology. - 2156-342X .- 2156-3446. ; 10:3, s. 321-330
-
Tidskriftsartikel (refereegranskat)abstract
- This article presents a packaging technique for monolithic microwave integrated circuits (MMIC) demonstrated in a fully integrated receiver (Rx) module at the D -band (110–170 GHz). The solution consists of an MMIC-to-waveguide transition realized using an on-chip probe mounted in the E -plane of a split-block waveguide module. An artificial magnetic conductor structure is implemented to suppress cavity modes and achieve better coupling from the waveguide to the probe. The transition's performance is experimentally verified using a back-to-back test chip, and measurement results show that the proposed packaging solution achieves a low insertion loss of only 0.7 dB and covers a very wide frequency range extending from 105 to 175 GHz. The proposed transition is also integrated with an in-phase/quadrature-phase (I/Q) Rx on the same chip. The Rx is realized in a 250-nm indium phosphide double heterojunction bipolar transistor technology and consists of a low-noise amplifier, an I/Q mixer, and a frequency tripler. Measurement results show that the Rx module achieves an average conversion gain of 23 dB across the frequency range of 110–145 GHz and has an average noise figure of 10.6 dB. The Rx MMIC has a dc power consumption of 440 mW and occupies an area of 1.6 × 1.6 mm 2 . This article addresses one of the main challenges in systems operating above 100 GHz and presents a fully integrated packaging solution that suits large integrated circuits and does not require any galvanic contacts nor impose any limitations on MMIC dimensions.
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| 34. |
- Hassona, Ahmed Adel, 1988, et al.
(författare)
-
Packaging Technique of Highly Integrated Circuits Based on EBG Structure for +100 GHz Applications
- 2020
-
Ingår i: 14th European Conference on Antennas and Propagation, EuCAP 2020.
-
Konferensbidrag (refereegranskat)abstract
- This work presents an on-chip packaging concept suitable for monolithic microwave integrated circuits (MMIC) operating above 100 GHz. The concept relies on using an on-chip transition that couples the signal to a standard air-filled waveguide. The proposed solution utilizes an electromagnetic band-gap (EBG) structure realized using bed of nails to prevent the propagation of parallel plate modes and improve the coupling between the MMIC and the waveguide. The technique shows an average insertion loss of only 0.6 dB across the frequency range 110 - 155 GHz. Moreover, the concept is demonstrated in a D-band amplifier circuitry that is fabricated in an indium phosphide (InP) double heterojunction bipolar transistor (DHBT) technology. Experimental results show that the amplifier exhibits a maximum gain of 18.5 dB with no sign of propagation of any parallel plate modes. This work presents a verified solution for packaging high-frequency integrated circuits, and hence paves the way towards higher system integration above 100 GHz.
|
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| 35. |
- Hassona, Ahmed Adel, 1988, et al.
(författare)
-
Silicon Taper Based D-Band Chip to Waveguide Interconnect for Millimeter-Wave Systems
- 2017
-
Ingår i: IEEE Microwave and Wireless Components Letters. - 1558-1764 .- 1531-1309. ; 27:12, s. 1092-1094
-
Tidskriftsartikel (refereegranskat)abstract
- This letter presents a novel interconnect for coupling millimeter-wave (mmW) signals from integrated circuits to air-filled waveguides. The proposed solution is realized through a slot antenna implemented in embedded wafer level ball grid array (eWLB) process. The antenna radiates into a high-resistivity (HR) silicon taper perpendicular to its plane, which in turn radiates into an air-filled waveguide. The interconnect achieves a measured average insertion loss of 3.4 dB over the frequency range of 116-151 GHz. The proposed interconnect is generic and does not require any galvanic contacts. The utilized eWLB packaging process is suitable for low-cost high-volume production and allows heterogeneous integration with other technologies. This letter proposes a straightforward cost-effective high-performance interconnect for mmW integration, and thus, addressing one of the main challenges facing systems operating beyond 100 GHz.
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| 36. |
- He, Zhongxia Simon, 1984, et al.
(författare)
-
A 140 GHz Transmitter with an Integrated Chip-to-Waveguide Transition using 130nm SiGe BiCMOS Process
- 2018
-
Ingår i: Asia Pacific Microwave Conference-Proceedings. - : IEEE. - 9784902339451 ; 2018-November, s. 28-30
-
Konferensbidrag (refereegranskat)abstract
- This paper presents a 140 GHz transmitter chipset realized in a 130 nm SiGe BiCMOS technology with f(t)/f(max) values of 250 GHz/ 370 GHz. This design comprises of a frequency sixtupler, a balanced transconductance mixer, an amplifier and chip-to-waveguide transition. The frequency multiplier operates in wide frequency band from 110-147 GHz, while the amplifier operates between 115-155 GHz. The total DC power consumption of the chipset is 420 mW. The chip size is 3 mm x 0.73 mm including chip-to-waveguide transition. The transmitter gives -4 dBm output power at 140 GHz and can operate between 129-148 GHz. Wireless data transmission up to 6 Gbps is measured using PSK and QAM modulation schemes.
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| 37. |
- He, Zhongxia Simon, 1984, et al.
(författare)
-
A Compact PCB Gasket for Waveguide Leakage Suppression at 110-170 GHz
- 2020
-
Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. ; 2020-August
-
Konferensbidrag (refereegranskat)abstract
- An electromagnetic bandgap (EBG) structure is implemented on a printed-circuit board (PCB) as gasket between waveguide flanges. The proposed gasket can reduce leakage between waveguide flanges due to misalignment. A WR-6.5 waveguide proof-of-concept demonstration is presented in this paper covering 110 - 170 GHz with a return loss lower than 12 dB and over a 75 um of air gap between the flanges.
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| 38. |
- Katsanos, Aristeidis H, et al.
(författare)
-
Blood Pressure After Endovascular Thrombectomy and Outcomes in Patients With Acute Ischemic Stroke: An Individual Patient Data Meta-analysis.
- 2022
-
Ingår i: Neurology. - 1526-632X. ; 98:3
-
Tidskriftsartikel (refereegranskat)abstract
- To explore the association between blood pressure (BP) levels after endovascular thrombectomy (EVT) and the clinical outcomes of acute ischemic stroke (AIS) patients with large vessel occlusion (LVO).A study was eligible if it enrolled AIS patients older than 18 years, with an LVO treated with either successful or unsuccessful EVT, and provided either individual or mean 24-hour systolic BP values after the end of the EVT procedure. Individual patient data from all studies were analyzed using a generalized linear mixed-effects model.A total of 5874 patients (mean age: 69±14 years, 50% women, median NIHSS on admission: 16) from 7 published studies were included. Increasing mean systolic BP levels per 10 mm Hg during the first 24 hours after the end of the EVT were associated with a lower odds of functional improvement (unadjusted common OR=0.82, 95%CI:0.80-0.85; adjusted common OR=0.88, 95%CI:0.84-0.93) and modified Ranking Scale score≤2 (unadjusted OR=0.82, 95%CI:0.79-0.85; adjusted OR=0.87, 95%CI:0.82-0.93), and a higher odds of all-cause mortality (unadjusted OR=1.18, 95%CI:1.13-1.24; adjusted OR=1.15, 95%CI:1.06-1.23) at 3 months. Higher 24-hour mean systolic BP levels were also associated with an increased likelihood of early neurological deterioration (unadjusted OR=1.14, 95%CI:1.07-1.21; adjusted OR=1.14, 95%CI:1.03-1.24) and a higher odds of symptomatic intracranial hemorrhage (unadjusted OR=1.20, 95%CI:1.09-1.29; adjusted OR=1.20, 95%CI:1.03-1.38) after EVT.Increased mean systolic BP levels in the first 24 hours after EVT are independently associated with a higher odds of symptomatic intracranial hemorrhage, early neurological deterioration, three-month mortality, and worse three-month functional outcomes.
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| 39. |
- Korany, Ahmed H., et al.
(författare)
-
Comparative structural analysis of different mycobacteriophage-derived mycolylarabinogalactan esterases (Lysin B)
- 2019
-
Ingår i: Biomolecules. - : MDPI AG. - 2218-273X. ; 10:1
-
Tidskriftsartikel (refereegranskat)abstract
- Mycobacteriophage endolysins have emerged as a potential alternative to the current antimycobacterial agents. This study focuses on mycolylarabinogalactan hydrolase (LysB) enzymes of the α/β-hydrolase family, which disrupt the unique mycolic acid layer of mycobacterium cell wall. Multiple sequence alignment and structural analysis studies showed LysB-D29, the only enzyme with a solved three-dimensional structure, to share several common features with esterases (lacking lid domain) and lipases (acting on long chain lipids). Sequence and structural comparisons of 30 LysB homology models showed great variation in domain organizations and total protein length with major differences in the loop-5 motif harboring the catalytic histidine residue. Docking of different p-nitrophenyl ligands (C4-C18) to LysB-3D models revealed that the differences in length and residues of loop-5 contributed towards wide diversity of active site conformations (long tunnels, deep and superficial funnels, shallow bowls, and a narrow buried cave) resembling that of lipases, cutinases, and esterases. A set of seven LysB enzymes were recombinantly produced; their activity against p-nitrophenyl esters could be related to their active site conformation and acyl binding site. LysB-D29 (long tunnel) showed the highest activity with long chain p-nitrophenyl palmitate followed by LysB-Omega (shallow bowl) and LysB-Saal (deep funnel).
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| 40. |
- Li, Y., et al.
(författare)
-
D-band SiGe transceiver modules based on silicon-micromachined integration
- 2019
-
Ingår i: Asia-Pacific Microwave Conference Proceedings, APMC. - : Institute of Electrical and Electronics Engineers (IEEE). ; 2019-December, s. 883-885
-
Konferensbidrag (refereegranskat)abstract
- This paper reports on 130 GHz transceiver modules consisting of integrated multi-functional chipsets in a commercial 130nm SiGe BiCMOS process. The interconnect between the chipset and the package is non-galvanic and is realized in silicon micromachining technique. After successful fabrication and assembly, the individual Tx and Rx modules as well as the combined Tx-Rx link were tested using CW signals. Then realtime data transport over the link were carried out using different modulation formats and bandwidths. With 16QAM over a 750 MHz channel a 2.66 Gbit/s data rate was demonstrated with BER<10-11. These tests show that the D-band modules, obtained in a single implementation trial, work well functionally. The interconnect method is applicable to the full D-band and expected to also support frequencies in the sub-millimeter-wave range where traditional methods become challenging to apply.
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| 41. |
- Sbarra, AN, et al.
(författare)
-
Mapping routine measles vaccination in low- and middle-income countries
- 2021
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 589:7842, s. 415-
-
Tidskriftsartikel (refereegranskat)abstract
- The safe, highly effective measles vaccine has been recommended globally since 1974, yet in 2017 there were more than 17 million cases of measles and 83,400 deaths in children under 5 years old, and more than 99% of both occurred in low- and middle-income countries (LMICs)1–4. Globally comparable, annual, local estimates of routine first-dose measles-containing vaccine (MCV1) coverage are critical for understanding geographically precise immunity patterns, progress towards the targets of the Global Vaccine Action Plan (GVAP), and high-risk areas amid disruptions to vaccination programmes caused by coronavirus disease 2019 (COVID-19)5–8. Here we generated annual estimates of routine childhood MCV1 coverage at 5 × 5-km2pixel and second administrative levels from 2000 to 2019 in 101 LMICs, quantified geographical inequality and assessed vaccination status by geographical remoteness. After widespread MCV1 gains from 2000 to 2010, coverage regressed in more than half of the districts between 2010 and 2019, leaving many LMICs far from the GVAP goal of 80% coverage in all districts by 2019. MCV1 coverage was lower in rural than in urban locations, although a larger proportion of unvaccinated children overall lived in urban locations; strategies to provide essential vaccination services should address both geographical contexts. These results provide a tool for decision-makers to strengthen routine MCV1 immunization programmes and provide equitable disease protection for all children.
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| 42. |
- Serhani, M. Adel, et al.
(författare)
-
Enterprise Web Services-enabled Translation Framework
- 2010
-
Ingår i: Information Systems and E-Business Management. - : Springer London. - 1617-9846 .- 1617-9854. ; 9:4, s. 497-517
-
Tidskriftsartikel (refereegranskat)abstract
- Managing multilingual documents is a time consuming, error prone and expensive task, particularly when dealing with dynamic documents such as web contents. A broad spectrum of organizations such as corporations, NGO’s and Governments are committed to offer such documents in a number of languages where the content is further localized to suit specific cultural settings. In this paper, we propose a business model supported by a web services-enabled framework, which facilitate all aspects related to multilingual web contents management, from negotiating translation-request quotations through production of final localized output as well as its verification, and delivery. This service is based on a collaborative internet-based translation framework, referred to in this paper as Translation Management System (TMS). Our approach uses XLIFF, a Web service standard developed by OASIS, in order to interoperate enterprise translation services and related Web applications. We present and implement a translation business model centered around standardized processes, which we validate through a case study in the context of a Web translation project. We also propose a QoS monitoring model to satisfy the quality-related requirements of a translation job. Finally, we evaluate the usability of our streamlined Web translation services through users’ perception in terms of flexibility, ease of use, and quality of translation. The results revealed interesting performance tradeoffs relative to translation workflows and content-translation accuracy as well as flexibility, and diversity of TMS provided services.
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| 43. |
- Thanh, Thi Ngoc Do, 1984, et al.
(författare)
-
A low-phase noise D-band signal source based on 130 nm SiGe BiCMOS and 0.15 mu m AlGaN/GaN HEMT technologies
- 2019
-
Ingår i: International Journal of Microwave and Wireless Technologies. - 1759-0787 .- 1759-0795. ; 11:5-6, s. 456-465
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports on a record-low-phase noise D-band signal source with 5 dBm output power, and 1.3 GHz tuning range. The source is based on the unconventional combination of a fundamental frequency 23 GHz oscillator in 150 nm AlGaN/GaN HEMT technology followed by a 130 nm SiGe BiCMOS MMIC including a sixtupler and an amplifier. The amplifier operates in compression mode as power-limiting amplifier, to equalize the source output power so that it is nearly independent of the oscillator's gate and drain bias voltages used for tuning the frequency of the source. The choice of using a GaN HEMT oscillator is motivated by the need for a low oscillator noise floor, which recently has been demonstrated as a bottle-neck for data rates in wideband millimeter-wave communication systems. The phase noise performance of this signal source is -128 dBc/Hz at 10 MHz-offset. To the best of the authors' knowledge, this result is the lowest reported phase noise of D-band signal source.
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| 44. |
- Vassilev, Vessen, 1969, et al.
(författare)
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Spectrum Efficient D-band Communication Link for Real-time Multi-gigabit Wireless Transmission
- 2018
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781538650677 ; 2018-June, s. 1523-1526
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Konferensbidrag (refereegranskat)abstract
- This manuscript presents results of wireless real-time data transmission at 143 GHz. The transmitter/receiver (Tx/Rx) front-end circuitry is integrated on a single monolithic microwave integrated circuits (MMICs), realized in a 250-nm indium phosphide (InP) double heterojunction bipolar transistor (DHBT) technology. The Tx module shows gain of 12 dB at 143 GHz with output power of -2.3 dBm at 1 dB gain compression. The Rx module has a gain of 15 dB with noise figure (NF) of 13 dB at 143 GHz. The minimum NF of 10 dB is measured at 132 GHz. The Tx/Rx front-end modules were integrated in two radio units to demonstrate a real time wireless data transmission. At a distance of 10 m and using 40 dBi gain antennas, the highest data rate achieved was 5.3 Gbit/s using 64 QAM modulation over a 1 GHz channel with spectrum efficiency of 5bit/s/Hz.
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| 45. |
- Yang Song-Yuan,, et al.
(författare)
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A D-band communication transmitter module with a novel self-aligned microstrip line-to-waveguide transition
- 2019
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Ingår i: Hongwai Yu Haomibo Xuebao/Journal of Infrared and Millimeter Waves. - 1001-9014. ; 38:3, s. 296-302
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Tidskriftsartikel (refereegranskat)abstract
- A D-band (110 similar to 170 GHz) transmitter module, based on a novel self-aligned microstrip-to-waveguide transition, was demonstrated. The simulated average insertion loss of the transition is about 0.6 dB and return loss is better than 10 dB during working band. A D-band transmitter module was developed using such transition with resistive mixer and multiplier chips. The transmitter module operates between 110 similar to 153 GHz and provides a peak saturated output power of -4.6 dBm at 150 GHz and with 13.5 GHz 3 dB bandwidth from 145.8 to 159.3 GHz. 3 Gb/s wireless communication with this module at 145 GHz was demonstrated with spectrum efficient 64-QAM modulation.
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