| 1. |
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| 2. |
- Ramdas, S., et al.
(författare)
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A multi-layer functional genomic analysis to understand noncoding genetic variation in lipids
- 2022
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Ingår i: American Journal of Human Genetics. - : Elsevier BV. - 0002-9297 .- 1537-6605. ; 109:8, s. 1366-1387
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Tidskriftsartikel (refereegranskat)abstract
- A major challenge of genome-wide association studies (GWASs) is to translate phenotypic associations into biological insights. Here, we integrate a large GWAS on blood lipids involving 1.6 million individuals from five ancestries with a wide array of functional genomic datasets to discover regulatory mechanisms underlying lipid associations. We first prioritize lipid-associated genes with expression quantitative trait locus (eQTL) colocalizations and then add chromatin interaction data to narrow the search for functional genes. Polygenic enrichment analysis across 697 annotations from a host of tissues and cell types confirms the central role of the liver in lipid levels and highlights the selective enrichment of adipose-specific chromatin marks in high-density lipoprotein cholesterol and triglycerides. Overlapping transcription factor (TF) binding sites with lipid-associated loci identifies TFs relevant in lipid biology. In addition, we present an integrative framework to prioritize causal variants at GWAS loci, producing a comprehensive list of candidate causal genes and variants with multiple layers of functional evidence. We highlight two of the prioritized genes, CREBRF and RRBP1, which show convergent evidence across functional datasets supporting their roles in lipid biology.
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| 3. |
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| 4. |
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| 5. |
- Bravo, L, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 6. |
- Tabiri, S, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 7. |
- Thomas, HS, et al.
(författare)
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- 2019
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swepub:Mat__t
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| 8. |
- Ruilope, LM, et al.
(författare)
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Design and Baseline Characteristics of the Finerenone in Reducing Cardiovascular Mortality and Morbidity in Diabetic Kidney Disease Trial
- 2019
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Ingår i: American journal of nephrology. - : S. Karger AG. - 1421-9670 .- 0250-8095. ; 50:5, s. 345-356
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Tidskriftsartikel (refereegranskat)abstract
- <b><i>Background:</i></b> Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. <b><i>Patients and</i></b> <b><i>Methods:</i></b> The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate ≥25 mL/min/1.73 m<sup>2</sup> and albuminuria (urinary albumin-to-creatinine ratio ≥30 to ≤5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level α = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. <b><i>Conclusions:</i></b> FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049.
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| 9. |
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| 10. |
- Glasbey, JC, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 11. |
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| 12. |
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| 13. |
- Khatri, C, et al.
(författare)
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Outcomes after perioperative SARS-CoV-2 infection in patients with proximal femoral fractures: an international cohort study
- 2021
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Ingår i: BMJ open. - : BMJ. - 2044-6055. ; 11:11, s. e050830-
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Tidskriftsartikel (refereegranskat)abstract
- Studies have demonstrated high rates of mortality in people with proximal femoral fracture and SARS-CoV-2, but there is limited published data on the factors that influence mortality for clinicians to make informed treatment decisions. This study aims to report the 30-day mortality associated with perioperative infection of patients undergoing surgery for proximal femoral fractures and to examine the factors that influence mortality in a multivariate analysis.SettingProspective, international, multicentre, observational cohort study.ParticipantsPatients undergoing any operation for a proximal femoral fracture from 1 February to 30 April 2020 and with perioperative SARS-CoV-2 infection (either 7 days prior or 30-day postoperative).Primary outcome30-day mortality. Multivariate modelling was performed to identify factors associated with 30-day mortality.ResultsThis study reports included 1063 patients from 174 hospitals in 19 countries. Overall 30-day mortality was 29.4% (313/1063). In an adjusted model, 30-day mortality was associated with male gender (OR 2.29, 95% CI 1.68 to 3.13, p<0.001), age >80 years (OR 1.60, 95% CI 1.1 to 2.31, p=0.013), preoperative diagnosis of dementia (OR 1.57, 95% CI 1.15 to 2.16, p=0.005), kidney disease (OR 1.73, 95% CI 1.18 to 2.55, p=0.005) and congestive heart failure (OR 1.62, 95% CI 1.06 to 2.48, p=0.025). Mortality at 30 days was lower in patients with a preoperative diagnosis of SARS-CoV-2 (OR 0.6, 95% CI 0.6 (0.42 to 0.85), p=0.004). There was no difference in mortality in patients with an increase to delay in surgery (p=0.220) or type of anaesthetic given (p=0.787).ConclusionsPatients undergoing surgery for a proximal femoral fracture with a perioperative infection of SARS-CoV-2 have a high rate of mortality. This study would support the need for providing these patients with individualised medical and anaesthetic care, including medical optimisation before theatre. Careful preoperative counselling is needed for those with a proximal femoral fracture and SARS-CoV-2, especially those in the highest risk groups.Trial registration numberNCT04323644
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| 14. |
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| 15. |
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| 16. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 17. |
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| 18. |
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| 19. |
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| 20. |
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| 21. |
- 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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| 22. |
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| 23. |
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| 24. |
- Zhang, Z. P., et al.
(författare)
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Effect of thermal annealing on structural properties of GeSn thin films grown by molecular beam epitaxy
- 2017
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Ingår i: AIP Advances. - : AIP Publishing. - 2158-3226 .- 2158-3226. ; 7:10
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Tidskriftsartikel (refereegranskat)abstract
- GeSn alloy with 7.68% Sn concentration grown by molecular beam epitaxy has been rapidly annealed at different temperatures from 300 degrees C to 800 degrees C. Surface morphology and roughness annealed below or equal to 500 degrees C for 1 min have no obvious changes, while the strain relaxation rate increasing. When the annealing temperature is above or equal to 600 degrees C, significant changes occur in surface morphology and roughness, and Sn precipitation is observed at 700 degrees C. The structural properties are analyzed by reciprocal space mapping in the symmetric (004) and asymmetric (224) planes by high resolution X-ray diffraction. The lateral correlation length and the mosaic spread are extracted for the epi-layer peaks in the asymmetric (224) diffraction. The most suitable annealing temperature to improve both the GeSn lattice quality and relaxation rate is about 500 degrees C.
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| 25. |
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| 26. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 27. |
- Wu, X. Y., et al.
(författare)
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1.142 mu m GaAsBi/GaAs Quantum Well Lasers Grown by Molecular Beam Epitaxy
- 2017
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Ingår i: ACS Photonics. - : American Chemical Society (ACS). - 2330-4022. ; 4:6, s. 1322-1326
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Tidskriftsartikel (refereegranskat)abstract
- As a promising new class of near-infrared light emitters, GaAsBi laser diodes (LDs) are considered to have a high energy efficiency and an insensitive temperature dependence of the band gap. In this paper, we realize the longest ever reported lasing wavelength up to 1.142 mu m at room temperature in GaAsBi0.058/GaAs quantum well LDs grown by molecular beam epitaxy. The output power is up to 127 mW at 300 K under pulsed mode. We also demonstrate continuous wave mode operation up to 273 K for the first time. The temperature coefficient of the GaAsBi/GaAs LD is 0.26 nm/K in the temperature range of 77-350 K, lower than that of both InGaAsP/InP and InGaAs/GaAs LDs. The characteristic temperature is extracted to be 139 K in the temperature range of 77-225 K and decreases to 79 K at 225-350 K.
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| 28. |
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| 29. |
- Zhang, Z. P., et al.
(författare)
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Growth mode of tensile-strained Ge quantum dots grown by molecular beam epitaxy
- 2017
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Ingår i: Journal of Physics D: Applied Physics. - : IOP Publishing. - 1361-6463 .- 0022-3727. ; 50:46
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Tidskriftsartikel (refereegranskat)abstract
- Growth mode of tensile-strained Ge quantum dots on different III-V buffers by molecular beam epitaxy is studied by a combination of reflection high-energy electron diffraction, atomic force microscopy and transmission electron microscopy. The Ge-QDs growth on the InAlAs buffer lattice matched to InP and on InAs buffer on GaSb follows the Volmer-Weber growth mode with round Ge QDs and no Ge wetting layer, while it obeys the Stranski-Krastanov growth mode on GaSb, AlSb and AlGaSb on GaSb substrates, showing rectangular shaped platelets and a clear Ge wetting layer. The discovery of the Volmer-Weber growth mode is essential to avoid forming a wetting layer and the subsequent antiphase-domain defects when capping III-Vs on Ge-QDs, important for potential optoelectronic applications.
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| 30. |
- Zhang, Z. P., et al.
(författare)
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Structural properties of GeSn thin films grown by molecular beam epitaxy
- 2017
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Ingår i: AIP Advances. - : AIP Publishing. - 2158-3226 .- 2158-3226. ; 7:4, s. Article number 045211-
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Tidskriftsartikel (refereegranskat)abstract
- GeSn thin films on Ge (001) with various Sn concentrations from 3.36 to 7.62% were grown by molecular beam epitaxy and characterized. The structural properties were analyzed by reciprocal space mapping in the symmetric (004) and asymmetric (224) planes by high resolution X-ray diffraction (XRD). The lateral correlation length (LCL) and the mosaic spread (MS) were extracted for the epi-layer peaks in the asymmetric (224) diffraction. With the increase of Sn concentration, the LCL reduces while the MS increases, indicating degrading crystalline quality. Dislocations were observed in the sample with 7.62% Sn concentration by transmission electron microscope, consistent with the strain relaxation found in XRD mapping. Besides, the surface morphologies were investigated.
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| 31. |
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| 32. |
- Blunden, Jessica, et al.
(författare)
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State of the Climate in 2012
- 2013
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Ingår i: Bulletin of The American Meteorological Society - (BAMS). - 0003-0007 .- 1520-0477. ; 94:8, s. S1-S258
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Tidskriftsartikel (refereegranskat)abstract
- For the first time in serveral years, the El Nino-Southern Oscillation did not dominate regional climate conditions around the globe. A weak La Ni a dissipated to ENSOneutral conditions by spring, and while El Nino appeared to be emerging during summer, this phase never fully developed as sea surface temperatures in the eastern conditions. Nevertheless, other large-scale climate patterns and extreme weather events impacted various regions during the year. A negative phase of the Arctic Oscillation from mid-January to early February contributed to frigid conditions in parts of northern Africa, eastern Europe, and western Asia. A lack of rain during the 2012 wet season led to the worst drought in at least the past three decades for northeastern Brazil. Central North America also experienced one of its most severe droughts on record. The Caribbean observed a very wet dry season and it was the Sahel's wettest rainy season in 50 years. Overall, the 2012 average temperature across global land and ocean surfaces ranked among the 10 warmest years on record. The global land surface temperature alone was also among the 10 warmest on record. In the upper atmosphere, the average stratospheric temperature was record or near-record cold, depending on the dataset. After a 30-year warming trend from 1970 to 1999 for global sea surface temperatures, the period 2000-12 had little further trend. This may be linked to the prevalence of La Ni a-like conditions during the 21st century. Heat content in the upper 700 m of the ocean remained near record high levels in 2012. Net increases from 2011 to 2012 were observed at 700-m to 2000-m depth and even in the abyssal ocean below. Following sharp decreases in to the effects of La Ni a, sea levels rebounded to reach records highs in 2012. The increased hydrological cycle seen in recent years continued, with more evaporation in drier locations and more precipitation in rainy areas. In a pattern that has held since 2004, salty areas of the ocean surfaces and subsurfaces were anomalously salty on average, while fresher areas were anomalously fresh. Global tropical cyclone activity during 2012 was near average, with a total of 84 storms compared with the 1981-2010 average of 89. Similar to 2010 and 2011, the North Atlantic was the only hurricane basin that experienced above-normal activity. In this basin, Sandy brought devastation to Cuba and parts of the eastern North American seaboard. All other basins experienced either near-or below-normal tropical cyclone activity. Only three tropical cyclones reached Category 5 intensity-all in Bopha became the only storm in the historical record to produce winds greater than 130 kt south of 7 N. It was also the costliest storm to affect the Philippines and killed more than 1000 residents. Minimum Arctic sea ice extent in September and Northern Hemisphere snow cover extent in June both reached new record lows. June snow cover extent is now declining at a faster rate (-17.6% per decade) than September sea ice extent (-13.0% per decade). Permafrost temperatures reached record high values in northernmost Alaska. A new melt extent record occurred on 11-12 July on the Greenland ice sheet; 97% of the ice sheet showed some form of melt, four times greater than the average melt for this time of year. The climate in Antarctica was relatively stable overall. The largest maximum sea ice extent since records begain in 1978 was observed in September 2012. In the stratosphere, warm air led to the second smallest ozone hole in the past two decades. Even so, the springtime ozone layer above Antarctica likely will not return to its early 1980s state until about 2060. Following a slight decline associated with the global 2 emissions from fossil fuel combustion and cement production reached a record 9.5 +/- 0.5 Pg C in 2011 and a new record of 9.7 +/- 0.5 Pg C is estimated for 2012. Atmospheric CO2 concentrations increased by 2.1 ppm in 2012, to 392.6 ppm. In spring 2012, 2 concentration exceeded 400 ppm at 7 of the 13 Arctic observation sites. Globally, other greenhouse gases including methane and nitrous oxide also continued to rise in concentration and the combined effect now represents a 32% increase in radiative forcing over a 1990 baseline. Concentrations of most ozone depleting substances continued to fall.
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| 33. |
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| 34. |
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| 35. |
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| 36. |
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| 37. |
- Han, Y., et al.
(författare)
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Suspended GeSn microstructure for light source on Si
- 2017
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Ingår i: 2017 IEEE Photonics Society Summer Topicals Meeting Series, SUM 2017, San Juan, Puerto Rico, 10-12 July 2017. - 9781509065707 ; , s. 69-70
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Konferensbidrag (refereegranskat)abstract
- A novel suspended GeSn microstructure is demonstrated by selective etching of GeSn thin film on Ge. XRD and ?-Raman measurements show that the compressive strain in the GeSn thin film is effectively relaxed, and furthermore, unexpected tensile strain was introduced in the suspended GeSn.
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| 38. |
- Liu, J. J., et al.
(författare)
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Bi2Te3 photoconductive detectors on Si
- 2017
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 110:14
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Tidskriftsartikel (refereegranskat)abstract
- The peculiar properties of the gapless surface states with a Dirac cone shaped energy dispersion in topological insulators (TIs) enable promising applications in photodetection with an ultra-broad band and polarization sensitivity. Since many TIs can be easily grown on silicon (Si) substrates, TIs on Si could make an alternative route for photon detection of Si photonics. We present good device performances of a Si-based single-crystal bismuth telluride (Bi2Te3) photoconductive detector. Room temperature photo responses to 1064 nm and 1550 nm light illumination were demonstrated. Linear dependences of the photocurrent on both the incident light power and the bias voltage were observed. The main device parameters including responsivity and quantum efficiency were extracted. Published by AIP Publishing.
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| 39. |
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| 40. |
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| 41. |
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| 42. |
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| 43. |
- Han, Delong, et al.
(författare)
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Analysis of Raman scattering from inclined GeSn/Ge dual-nanowire heterostructure on Ge(1 1 1) substrate
- 2019
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Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332. ; 463, s. 581-586
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the Raman spectra of GeSn/Ge dual-nanowire heterostructure grown on Ge(1 1 1) substrate are systematically analyzed within the framework of anisotropic elasticity and lattice dynamical theory. Based on the experimental samples grown by molecular beam epitaxy, the partially covered dual nanowires standing along 〈1 1 0〉 direction are modeled and the heterostructure presents effective elastic strain relaxation due to the free surfaces. The simulations show that the Raman shift of GeSn nanowire is mainly affected by the Sn content while the influences of strain become less important with the increase of thickness ratio. For Ge nanowire, the peak of Raman spectrum merely moves with Sn content, but the spectrum possesses asymmetric broadening induced by the non-uniform strain distribution. The red-shift and intensity reduction of the total Raman spectrum of dual nanowires are observed when the Sn content increases. Moreover, an analytic fitting expression for Raman peak position is obtained based on the numerical results and is expected to serve as a reference to estimate the Sn content in GeSn/Ge dual-nanowire heterostructure.
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| 44. |
- Han, Y., et al.
(författare)
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A comparative study of selective dry and wet etching of germanium-tin (Ge1-xSnx) on germanium
- 2018
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Ingår i: Semiconductor Science and Technology. - : IOP Publishing. - 1361-6641 .- 0268-1242. ; 33:8
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Tidskriftsartikel (refereegranskat)abstract
- A comparative study of selective dry and wet etching methods for germanium-tin (Ge1-xSnx) alloys (3.5% < x < 7.7%) and germanium (Ge) is carried out. Both etching methods are optimized from the perspectives of selectivity and morphology, and then compared. A special behavior of the selective dry etching process is discovered and explained, whereby the selectivity has a dramatic increase to as high as 336 when the Sn concentration is above 6%. Different morphologies of suspended microstructures fabricated by different etching methods are investigated. Comparative study shows that the selective dry etching is a better choice for high Sn concentration GeSn (above 7%) against Ge to have better morphology, selectivity and verticality. While for low Sn concentration GeSn (below 6%), wet etching is a better way to fabricate a suspended GeSn microstructure on Ge. This work provides a comparative understanding of both methods of selective etching for GeSn. This comparative understanding is expected to be applied in the processing of next generation electronic and photonic devices.
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| 45. |
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| 46. |
- Krammel, C. M., et al.
(författare)
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Incorporation of Bi atoms in InP studied at the atomic scale by cross-sectional scanning tunneling microscopy
- 2017
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Ingår i: Physical Review Materials. - 2475-9953. ; 1:3
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Tidskriftsartikel (refereegranskat)abstract
- We show the potential of cross-sectional scanning tunneling microscopy to address structural properties of dilute III-V bismides by investigating Bi:InP. Bismuth atoms down to the second monolayer below the {110} InP surfaces, which give rise to three classes of distinct contrast, are identified with the help of density functional theory calculations. Based on this classification, the pair-correlation function is used to quantify the ordering of Bi atoms on the long range. In a complementary short-ranged study, we investigate the Bi ordering at the atomic level. An enhanced tendency for the formation of first-nearest-neighbor Bi pairs is found. In addition, the formation of small Bi clusters is observed whose geometries appear to be related to strong first-nearest-neighbor Bi pairing. We also identify growth related crystal defects, such as In vacancies, P antisites, and Bi antisites.
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| 47. |
- Krammel, C. M., et al.
(författare)
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Probing the local electronic structure of isovalent Bi atoms in InP
- 2020
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Ingår i: Physical Review B. - 2469-9969 .- 2469-9950. ; 101:2
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Tidskriftsartikel (refereegranskat)abstract
- Cross-sectional scanning tunneling microscopy (X-STM) is used to experimentally study the influence of isovalent Bi atoms on the electronic structure of InP. We map the spatial pattern of the Bi impurity state, which originates from Bi atoms down to the sixth layer below the surface, in topographic, filled-state X-STM images on the natural {110} cleavage planes. The Bi impurity state has a highly anisotropic bowtielike structure and extends over several lattice sites. These Bi-induced charge redistributions extend along the < 110 > directions, which define the bowtielike structures we observe. Local tight-binding calculations reproduce the experimentally observed spatial structure of the Bi impurity state. In addition, the influence of the Bi atoms on the electronic structure is investigated in scanning tunneling spectroscopy measurements. These measurements show that Bi induces a resonant state in the valence band, which shifts the band edge toward higher energies. Furthermore, we show that the energetic position of the Bi-induced resonance and its influence on the onset of the valence band edge depend crucially on the position of the Bi atoms relative to the cleavage plane.
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| 48. |
- Li, Y., et al.
(författare)
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Novel group IV nano- and micro-structures for light sources on silicon
- 2017
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Ingår i: 2017 IEEE Photonics Society Summer Topicals Meeting Series, SUM 2017; San Juan Marriott ResortSan Juan; Puerto Rico; 10 July 2017 through 12 July 2017. - 9781509065707 ; , s. 43-44
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Konferensbidrag (refereegranskat)abstract
- We present our recent researches on novel group IV nano- and micro-structures for potential light sources on Si, including the tensile strained Ge quantum dots (QDs), GeSn thin films and microstructures, and Ge(Sn) nanowires. Tensile-strained Ge QDs were grown by SS-MBE, and photoluminescence was achieved. The GeSn thin films were demonstrated with Sn concentration above the bandgap transition critical point, and partially suspended GeSn microstructures were fabricated for relaxing the compressive strain.
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| 49. |
- Mahajan, Anubha, et al.
(författare)
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Multi-ancestry genetic study of type 2 diabetes highlights the power of diverse populations for discovery and translation
- 2022
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Ingår i: Nature Genetics. - : Springer Nature. - 1061-4036 .- 1546-1718. ; 54:5, s. 560-572
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Tidskriftsartikel (refereegranskat)abstract
- We assembled an ancestrally diverse collection of genome-wide association studies (GWAS) of type 2 diabetes (T2D) in 180,834 affected individuals and 1,159,055 controls (48.9% non-European descent) through the Diabetes Meta-Analysis of Trans-Ethnic association studies (DIAMANTE) Consortium. Multi-ancestry GWAS meta-analysis identified 237 loci attaining stringent genome-wide significance (P < 5 x 10(-9)), which were delineated to 338 distinct association signals. Fine-mapping of these signals was enhanced by the increased sample size and expanded population diversity of the multi-ancestry meta-analysis, which localized 54.4% of T2D associations to a single variant with >50% posterior probability. This improved fine-mapping enabled systematic assessment of candidate causal genes and molecular mechanisms through which T2D associations are mediated, laying the foundations for functional investigations. Multi-ancestry genetic risk scores enhanced transferability of T2D prediction across diverse populations. Our study provides a step toward more effective clinical translation of T2D GWAS to improve global health for all, irrespective of genetic background. Genome-wide association and fine-mapping analyses in ancestrally diverse populations implicate candidate causal genes and mechanisms underlying type 2 diabetes. Trans-ancestry genetic risk scores enhance transferability across populations.
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| 50. |
- Pan, W. W., et al.
(författare)
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Optical properties and band bending of InGaAs/GaAsBi/InGaAs type-II quantum well grown by gas source molecular beam epitaxy
- 2016
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 120:10
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Tidskriftsartikel (refereegranskat)abstract
- Photoluminescence (PL) properties of In0.2Ga0.8As/GaAs0.96Bi0.04/In0.2Ga0.8As quantum well (QW) grown on GaAs substrates by gas source molecular beam epitaxy were studied by varying excitation power and temperature, respectively. The type-II transition energy shifts from 1.149 eV to 1.192 eV when increasing the excitation power from 10 mW to 150 mW at 4.5 K, which was ascribed to the band-bending effect. On the other hand, the type-II PL quenches quickly along with fast redshift with the increasing temperature due to the relaxation of the band bending caused by the thermal excitation process. An 8 band k.p model was used to analyze the electronic properties and the band-bending effect in the type-II QW. The calculated subband levels and transition energy fit well with the experiment results, and two thermal activation energies of 8.7 meV and 50 meV, respectively, are deduced. Published by AIP Publishing.
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