SwePub
Tyck till om SwePub Sök här!
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Hellström Per Erik) "

Sökning: WFRF:(Hellström Per Erik)

  • Resultat 1-10 av 182
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Sjöberg, Mats, 1965-, et al. (författare)
  • Infliximab or cyclosporine as rescue therapy in hospitalized patients with steroid-refractory ulcerative colitis : a retrospective observational study
  • 2012
  • Ingår i: Inflammatory Bowel Diseases. - : John Wiley & Sons. - 1078-0998 .- 1536-4844. ; 18:2, s. 212-218
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Cyclosporine (CsA) or infliximab (IFX) are used as rescue therapies in steroid-refractory, severe attacks of ulcerative colitis (UC). There are no data comparing the efficacy of these two alternatives. Methods: Outcome of rescue therapy was retrospectively studied in two cohorts of patients hospitalized due to steroid-refractory moderate to severe UC: 1) a Swedish-Danish cohort (n 49) treated with a single infusion of IFX; 2) an Austrian cohort (n 43) treated with intravenous CsA. After successful rescue therapy, maintenance immunomodulator treatment was given to 27/33 (82%) of IFX patients and to 31/40 (78%) of CsA patients. Endpoints were colectomy-free survival at 3 and 12 months. Kaplan-Meier and Cox regression models were used to evaluate the association between treatment groups and colectomy. Results: At 15 days, colectomy-free survival in the IFX cohort was 36/49 (73%) versus 41/43 (95%) in the CsA cohort (P = 0.005), at 3 months 33/49 (67%) versus 40/43 (93%) (P = 0.002), and at 12 months 28/49 (57%) versus 33/43 (77%) (P = 0.034). After adjusting for potential confounding factors, Cox regression analysis yielded adjusted hazard ratios for risk of colectomy in IFX-treated patients of 11.2 (95% confidence interval [CI] 2.4-53.1, P = 0.002) at 3 months and of 3.0 (95% CI 1.1-8.2, P = 0.030) at 12 months in comparison with CsA-treated patients. There were no opportunistic infections or mortality. Conclusions: Colectomy frequencies were significantly lower after rescue therapy with CsA than with a single infusion of IFX both at 3 and 12 months' follow-up. The superiority of CsA was seen principally during the first 15 days.
  •  
2.
  • Andersson, Henrik (författare)
  • Development of Process Technology for Photon Radiation Measurement Applications
  • 2007
  • Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • This thesis presents work related to new types of photo detectors and their applications. The focus has been on the development of process technology and methods by means of experimentation and measurements. The overall aim has been to develop and improve photon radiation measurement applications which are possible to manufacture using standard Si processing technology. A new type of position sensitive detector that has switching possibilities based on the MOS principle has been fabricated and characterized. The influence of mechanical stress on the linearity of position sensitive detectors has been investigated. The results show that mechanical stress arising, for example, by the mounting of detectors in capsules can have an impact on device performance. Under normal circumstances these effects are rather small, but are considered to be worthwhile taking into account. Electroless deposition of Nickel including various dopants in porous silicon was performed to manufacture electrical contacts for this interesting material. After heat treatment it was confirmed by X-ray diffraction that Nickel silicide had been formed and I-V measurements show that different contacts exhibit Ohmic and rectifying behaviour. Spectrometers are used extensively in the process and food industry to measure both the chemical content and the amount of substances used during manufacturing. These instruments are often rather bulky and costly, though the trend is towards smaller and more portable equipment. A spectrometer based on an array of Fabry-Perot interferometers mounted close to an array detector is shown to be a viable option for the manufacture of a very compact device. Such a device has minimal intermediate optics and it may be possible, in the future, for it to be developed and completely integrated with a detector array into a single unit.
  •  
3.
  •  
4.
  • Witte, Anne-Barbara, et al. (författare)
  • Involvement of endogenous glucagon-like peptide-1 in regulation of gastric motility and pancreatic endocrine secretion
  • 2011
  • Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 46:4, s. 428-435
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective. To study the role of endogenous glucagon-like peptide-1 (GLP-1) on gastric emptying rates of a solid meal as well as postprandial hormone secretion and glucose disposal. Material and methods. In nine healthy subjects, gastric emptying of a 310-kcal radio-labelled solid meal and plasma concentrations of insulin, glucagon and glucose were measured during infusion of saline or the GLP-1 receptor antagonist exendin(9-39)amide (Ex(9-39)) at 300 pmol·kg−1·min−1. Results. Ex(9-39) infusion had no effect on the total gastric emptying curve, but changed the intra-gastric distribution of the meal. During infusion of Ex(9-39), more content stayed in the upper stomach (79.1 ± 2.5% of total during Ex(9-39) compared to 66.6 ± 5.7% during saline at 5 min). During Ex(9-39) infusion, higher concentrations of plasma glucagon were measured both before (after 40 min of Ex(9-39) infusion the glucagon level was 15.1 ± 0.7 pmol·L−1 compared to 5.4 ± 1.4 during saline) and after the meal, and postprandial GLP-1 levels increased. Basal insulin and glucose levels were not affected by Ex(9-39), but the postprandial rise of insulin and glucose enhanced during Ex(9-39). Conclusions. Endogenous GLP-1 is involved in the regulation of gastric motility in relation to meal intake and also in the regulation of postprandial insulin and glucose levels. Furthermore, endogenous GLP-1 seems to tonically restrain glucagon secretion.
  •  
5.
  • Abedin, Ahmad, et al. (författare)
  • Epitaxial growth of Ge strain relaxed buffer on Si with low threading dislocation density
  • 2016
  • Ingår i: ECS Transactions. - : Electrochemical Society. - 1938-5862 .- 1938-6737. - 9781607685395 ; , s. 615-621
  • Konferensbidrag (refereegranskat)abstract
    • Epitaxial Ge with low dislocation density is grown on a low temperature grown Ge seed layer on Si substrate by reduced pressure chemical vapor deposition. The surface topography measured by AFM shows that the strain relaxation occurred through pit formation which resulted in freezing the defects at Ge/Si interface. Moreover a lower threading dislocation density compared to conventional strain relaxed Ge buffers on Si was observed. We show that by growing the first layer at temperatures below 300 °C a surface roughness below 1 nm can be achieved together with carrier mobility enhancement. The different defects densities revealed from SECCO and Iodine etching shows that the defects types have been changed and SECCO is not always trustable.
  •  
6.
  • Abedin, Ahmad, et al. (författare)
  • Germanium on Insulator Fabrication for Monolithic 3-D Integration
  • 2018
  • Ingår i: IEEE Journal of the Electron Devices Society. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 2168-6734. ; 6:1, s. 588-593
  • Tidskriftsartikel (refereegranskat)abstract
    • A low temperature (T-max = 350 degrees C) process for Germanium (Ge) on insulator (GOI) substrate fabrication with thicknesses of less than 25 nm is reported in this paper. The process is based on a single step epitaxial growth of a Ge/SiGe/Ge stack on Si, room temperature wafer bonding and an etch-back process using Si0.5Ge0.5 as an etch-stop layer. GOI substrates with surface roughness below 0.5 nm, 0.15% tensile strain, thickness nonuniformity of less than 3 nm and residual p-type doping of less than 1016 cm(-3) were fabricated. Ge pFETs are fabricated (T-max = 600 degrees C) on the GOI wafer with 70% yield. The devices exhibit a negative threshold voltage of -0.18 V and 60% higher mobility than the SOI pFET reference devices.
  •  
7.
  • Abedin, Ahmad, et al. (författare)
  • GOI fabrication for monolithic 3D integration
  • 2018
  • Ingår i: 2017 IEEE SOI-3D-Subthreshold Microelectronics Unified Conference, S3S 2017. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781538637654 ; , s. 1-3
  • Konferensbidrag (refereegranskat)abstract
    • A low temperature (Tmax=350 °C) process for Ge on insulator (GOI) substrate fabrication with thicknesses of less than 25 nm is reported in this work. The process is based on a single step epitaxial growth of a Ge/SiGe/Ge stack on Si, room temperature wafer bonding, and an etch-back process using Si0.5Ge0.5 as an etch-stop layer. Using this technique, GOI substrates with surface roughness below 0.5 nm, thickness nonuniformity of less than 3 nm, and residual p-type doping of less than 1016 cm-3 are achieved. Ge pFETs are fabricated (Tmax=600 °C) on the GOI wafer with 70% yield. The devices exhibit a negative threshold voltage of-0.18 V and 60% higher mobility than the SOI pFET reference devices.
  •  
8.
  • Abedin, Ahmad, et al. (författare)
  • Growth of epitaxial SiGe alloys as etch-stop layers in germanium-on-insulator fabrication
  • Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
    • In this study, the application of epitaxially grown SixGe1-x films as etch stop layers in a germanium-on-insulator substrate fabrication flow is investigated. Layers with Ge contents from 15% to 70% were epitaxially grown on Si (1 0 0) using silane and germane. It was found that the Ge content in the films is independent of the growth temperature for fixed partial pressure ratios. At low growth temperatures the activation energy is found to be 1.8 eV which points to a hydrogen desorption limited growth rate mechanism. At growth temperatures of less than 500℃, the surface roughness is <1 nm. This surface roughness does not change when the films are grown on Ge substrates. Finally, a fully strained Si0.5Ge0.5 film was grown on Ge strain relaxed buffer at 450℃. This layer demonstrates etch selectivity of >400:1 towards Ge in diluted SC-1. This result enables the integration of the Si0.5Ge0.5 film as an etch stop layer for single crystalline germanium-on-insulator substrate fabrication.
  •  
9.
  • Asadollahi, Ali, et al. (författare)
  • Fabrication of relaxed germanium on insulator via room temperature wafer bonding
  • 2014
  • Ingår i: ECS Transactions. - : Electrochemical Society. - 1938-6737. ; , s. 533-541
  • Konferensbidrag (refereegranskat)abstract
    • We report on the fabrication of, high quality, monocrystalline relaxed Germanium with ultra-low roughness on insulator (GeOI) using low-temperature direct wafer bonding. We observe that a two-step epitaxially grown germanium film fabricated on silicon by reduced pressure chemical vapor deposition can be directly bonded to a SiO2 layer using a thin Al2O3 as bonding mediator. After removing the donor substrate silicon the germanium layer exhibits a complete relaxation without degradation in crystalline quality and no stress in the film. . The results suggest that the fabricated high quality GeOI substrate is a suitable platform for high performance device applications.
  •  
10.
  • Asadollahi, Ali, et al. (författare)
  • Fabrication of strained Ge on insulator via room temperature wafer bonding
  • 2014
  • Ingår i: 2014 15th International Conference on Ultimate Integration on Silicon, ULIS 2014. - : IEEE Computer Society. - 9781479937189 ; , s. 81-84
  • Konferensbidrag (refereegranskat)abstract
    • This work describes a strained germanium on insulator (GeOI) fabrication process using wafer bonding and etch-back techniques. The strained Ge layer is fabricated epitaxially using reduced pressure chemical vapor deposition (RPCVD). The strained Ge is grown pseudomorphic on top of a partially relaxed Si 0.66Ge0.34 layer. Wafer bonding is performed at room temperature without post-anneal processes and the etch-back steps are performed without mechanical grinding and chemical mechanical polishing (CMP).
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-10 av 182
Typ av publikation
tidskriftsartikel (100)
konferensbidrag (59)
doktorsavhandling (10)
annan publikation (5)
bokkapitel (4)
rapport (2)
visa fler...
samlingsverk (redaktörskap) (1)
licentiatavhandling (1)
visa färre...
Typ av innehåll
refereegranskat (154)
övrigt vetenskapligt/konstnärligt (26)
populärvet., debatt m.m. (2)
Författare/redaktör
Östling, Mikael (117)
Hellström, Per-Erik (102)
Hellström, Per-Erik, ... (38)
Zhang, Shi-Li (28)
Hellström, Per M. (15)
Malm, B. Gunnar (12)
visa fler...
Radamson, Henry H. (11)
Asadollahi, Ali (11)
Jayakumar, Ganesh (11)
Henkel, Christoph (11)
Abedin, Ahmad (10)
Zurauskaite, Laura (10)
Garidis, Konstantino ... (9)
Malm, Gunnar (9)
Hållstedt, Julius (9)
Lu, J. (7)
Näslund, Erik (7)
Zhang, Zhen (7)
Webb, Dominic-Luc (6)
Naslund, Erik (6)
Kasper, E. (6)
Lu, Jun (5)
Hellström, Per M., 1 ... (5)
Hertervig, Erik (5)
Blundell, John E (5)
Radamson, Henry (4)
Luo, Jun (4)
Wu, D. (4)
Persson, Stefan (4)
Oehme, M. (4)
Östling, Mikael, Pro ... (3)
Hellström, Åke (3)
Evans, D. (3)
Wahlund, Lars-Olof (3)
Malm, B. Gunnar, 197 ... (3)
Persson, S (3)
Olsson, Jörgen (3)
Verbaan, Hans (3)
Hellström, Per (3)
O'Neill, A.G. (3)
Ström, Magnus (3)
Rodriguez, Saul (3)
Sanger, Gareth J. (3)
Ivanov, R. (3)
Hall, S. (3)
Almqvist, S (3)
Dhanak, V. R. (3)
Rudholm, Tobias (3)
Östberg, Per (3)
Malm, Gunnar, 1972- (3)
visa färre...
Lärosäte
Kungliga Tekniska Högskolan (141)
Uppsala universitet (31)
Karolinska Institutet (18)
Linköpings universitet (7)
Göteborgs universitet (5)
Lunds universitet (5)
visa fler...
Örebro universitet (4)
Chalmers tekniska högskola (4)
Röda Korsets Högskola (4)
Stockholms universitet (3)
Umeå universitet (2)
Mittuniversitetet (2)
Högskolan Dalarna (2)
Luleå tekniska universitet (1)
Linnéuniversitetet (1)
Sveriges Lantbruksuniversitet (1)
IVL Svenska Miljöinstitutet (1)
visa färre...
Språk
Engelska (178)
Svenska (3)
Odefinierat språk (1)
Forskningsämne (UKÄ/SCB)
Teknik (111)
Naturvetenskap (25)
Medicin och hälsovetenskap (22)
Samhällsvetenskap (5)
Humaniora (2)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy