| 1. |
- Aad, G., et al.
(författare)
-
The ATLAS Experiment at the CERN Large Hadron Collider
- 2008
-
Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08003
-
Forskningsöversikt (refereegranskat)abstract
- The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper. A brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented.
|
|
| 2. |
- Gottlob, H. D. B., et al.
(författare)
-
Scaling potential and MOSFET integration of thermally stable Gd silicate dielectrics
- 2009
-
Ingår i: Microelectronic Engineering. - : Elsevier BV. - 0167-9317 .- 1873-5568. ; 86:7-9, s. 1642-1645
-
Tidskriftsartikel (refereegranskat)abstract
- We investigate the potential of gadolinium silicate (GdSiO) as a thermally stable high-k gate dielectric in a gate first integration scheme. There silicon diffuses into gadolinium oxide (Gd2O3) from a silicon oxide (SiO2) interlayer specifically prepared for this purpose. We report on the scaling potential based on detailed material analysis. Gate leakage current densities and EOT values are compatible with an ITRS requirement for low stand by power (LSTP). The applicability of this GdSiO process is demonstrated by fully functional silicon on insulator (SOI) metal oxide semiconductor field effect transistors (MOSFETs). (C) 2009 Elsevier B.V. All rights reserved.
|
|
| 3. |
|
|
| 4. |
- Balestra, F., et al.
(författare)
-
NANOSIL network of excellence-silicon-based nanostructures and nanodevices for long-term nanoelectronics applications
- 2008
-
Ingår i: Materials Science in Semiconductor Processing. - : Elsevier BV. - 1369-8001 .- 1873-4081. ; 11:5-6, s. 148-159
-
Tidskriftsartikel (refereegranskat)abstract
- NANOSIL Network of Excellence [NANOSIL NoE web site < www.nanosil-noe.eu >], funded by the European Commission in the 7th Framework Programme (ICT-FP7, no 216171), aims at European scale integration of the excellent European research laboratories and their capabilities in order to strengthen scientific and technological excellence in the field of nanoelectronic materials and devices for terascale integrated circuits (ICs), and to disseminating the results in a wide scientific and industrial community. NANOSIL is exploring and assessing the science and technological aspects of nanodevices and operational regimes relevant to the n+4 technology node and beyond. It encompasses projects on nanoscale CMOS and beyond-CMOS. Innovative concepts, technologies and device architectures are proposed-with fabrication down to the finest features, and utilising a wide spectrum of advanced deposition and processing capabilities, extensive characterization and very rigorous device modeling. This work is carried out through a network of joint processing, characterization and modeling platforms. This critical interaction strengthens European integration in nanoelectronics and will speed up technological innovation for the nanoelectronics of the next two to three decades.
|
|
| 5. |
|
|
| 6. |
- Engström, A. C., et al.
(författare)
-
Improved accessibility and reactivity of dissolving pulp for the viscose process : Pretreatment with monocomponent endoglucanase
- 2006
-
Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 7:6, s. 2027-2031
-
Tidskriftsartikel (refereegranskat)abstract
- A high accessibility is an essential prerequisite for a homogeneous substitution of cellulose material. In this study, chemical and enzymatic pretreatments to increase the accessibility of cellulose materials have been investigated. Dissolving pulp has been treated with a monocomponent endoglucanase. Fock's method, a microscale process similar to the viscose process, showed an increase in cellulose yield. Simultaneously, the viscosity decreased. To clarify whether the increase in reactivity was due solely to the decrease in the degree of polymerization, the dissolving pulp was also subjected to acid hydrolysis. At a given viscosity level, the enzymatic pretreated pulp had a higher reactivity than the pulp subjected to acid hydrolysis. To achieve 100% reactivity, according to Fock, the acid-treated pulp showed a lower molecular weight compared to the enzymatic-treated pulp. A monocomponent endoglucanase can thus be used to increase the reactivity and accessibility of dissolving pulp in the viscose process.
|
|
| 7. |
|
|
| 8. |
- Engström, Katarina, 1956, et al.
(författare)
-
Liposarcoma: outcome based on the Scandinavian Sarcoma Group register.
- 2008
-
Ingår i: Cancer. - : Wiley. - 0008-543X .- 1097-0142. ; 113:7, s. 1649-56
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aim was to study the clinicopathological characteristics, treatment, and outcome of liposarcoma in an unselected, population-based patient sample, and to establish whether treatment was according to the Scandinavian Sarcoma Group (SSG) treatment guidelines. METHODS: The SSG Pathology Board reviewed 319 liposarcoma cases reported between 1986 and 1998. After the review, 237 patients without metastasis were analyzed for local recurrence rate in relation to surgical margins, radiotherapy, occurrence of metastasis, and survival. RESULTS: Seventy-eight percent of the patients were primarily operated on at a sarcoma center, 45% with wide margins. All patients operated on outside the center had nonwide margins. Low-grade lesions constituted 67% of cases. Despite nonwide surgery, only 58% of high-grade lesions were treated with postoperative radiotherapy. The risk of local recurrence after nonwide surgery, without irradiation, was 47% for high-grade lesions. The estimated 10-year, local recurrence-free and metastasis-free survival in the low-grade group was 87% and 95%, respectively. In the high-grade group, it was 75% and 61%, respectively. Independent adverse prognostic factors for local recurrence were surgery outside a sarcoma center and histological type dedifferentiated liposarcoma. For metastases, they were old age, large tumor size, high grade, and histological type myxoid liposarcoma with a round cell component. Radiotherapy showed significant effect on local recurrence rate for the same grade and margin. CONCLUSIONS: Patients with liposarcoma should be treated at specialized centers. Postoperative radiotherapy decreases the local recurrence rate. To maintain quality and provide support for further trials, reporting to quality registers is crucial.
|
|
| 9. |
- Engström, Olof, 1943, et al.
(författare)
-
A generalised methodology for oxide leakage current metric
- 2008
-
Ingår i: Proceeding of 9th European Workshop on Ultimate Integration of Silicon (ULIS), Udine, Italy. - 9781424417308 ; , s. 167-
-
Konferensbidrag (refereegranskat)abstract
- From calculations of semiconductor interfacecharge, oxide voltage and tunneling currents for MOSsystems with equivalent oxide thickness (EOT) in therange of 1 nm, rules are suggested for making itpossible to compare leakage quality of different oxideswith an accuracy of a factor 2 – 3 if the EOT is known.The standard procedure suggested gives considerablybetter accuracy than the commonly used method todetermine leakage at VFB+1V for n-type and VFB-1V forp-type substrates.
|
|
| 10. |
|
|
| 11. |
- Engström, Pia, 1970, et al.
(författare)
-
Anaerobic ammonium oxidation by nitrite (anammox): Implications for N-2 production in coastal marine sediments
- 2005
-
Ingår i: Geochimica Et Cosmochimica Acta. - : Elsevier BV. - 0016-7037. ; 69:8, s. 2057-2065
-
Tidskriftsartikel (refereegranskat)abstract
- The respiratory reduction of nitrate (denitrification) is acknowledged as the most important process that converts biologically available nitrogen to gaseous dinitrogen (N-2) in marine ecosystems. Recent findings, however, indicate that anaerobic ammonium oxidation by nitrite (anammox) may be an important pathway for N-2 formation and N removal in coastal marine sediments and in anoxic water columns of the oceans. In the present study, we explored this novel mechanism during N mineralization by 15 N amendments (single and coupled additions of (NH4+)-N-15, (NO3-)-N-14 and (NO3-)-N-15) to surface sediments with a wide range of characteristics and overall reactivity. Patterns of N-29/30(2) production in the pore water during closed sediment incubations demonstrated anammox at all 7 of the investigated sites. Stoichiometric calculations revealed that 4% to 79% of total N-2 production was due to this novel route. The relative importance of anammox for N2 release was inversely correlated with remineralized solute production, benthic O-2 consumption, and surface sediment Ch1 a. The observed correlations indicate competition between reductants for pore water nitrite during early diagenesis and that additional factors (e.g. availability of Mn-oxides), superimposed on overall patterns of diagenetic activity, are important for determining absolute and relative rates of anammox in coastal marine sediments. Copyright (c) 2005 Elsevier Ltd
|
|
| 12. |
|
|
| 13. |
- Gagliardi, F. M., et al.
(författare)
-
Intra-cavitary dosimetry for IMRT head and neck treatment using thermoluminescent dosimeters in a naso-oesophageal tube
- 2009
-
Ingår i: Physics in Medicine and Biology. - : IOP Publishing. - 1361-6560 .- 0031-9155. ; 54:12, s. 3649-3657
-
Tidskriftsartikel (refereegranskat)abstract
- Complex intensity-modulated radiation therapy (IMRT) treatment plans require rigorous quality assurance tests. The aim of this study was to independently verify the delivered dose inside the patient in the region of the treatment site. A flexible naso-gastric tube containing thermoluminescent dosimeters (TLDs) was inserted into the oesophagus via the sinus cavity before the patient's first treatment. Lead markers were also inserted into the tube in order that the TLD positions could be accurately determined from the lateral and anterior posterior electronic portal images taken prior to treatment. The measured dose was corrected for both daily linac output variations and the estimated dose received from the portal images. The predicted dose for each TLD was determined from the treatment planning system and compared to the measured TLD doses. The results comprise 431 TLD measurements on 43 patients. The mean measured-to-predicted dose ratio was 0.988 +/- 0.011 (95% confidence interval) for measured doses above 0.2 Gy. There was a variation in this ratio when the measurements were separated into low dose (0.2-1.0 Gy), medium dose (1.0-1.8 Gy) and high dose (> 1.8 Gy) measurements. The TLD-loaded, naso-oesophageal tube for in vivo dose verification is straightforward to implement, and well tolerated by patients. It provides independent reassurance of the delivered dose for head and neck IMRT.
|
|
| 14. |
- Gottlob, H. D. B., et al.
(författare)
-
Gd silicate : A high-k dielectric compatible with high temperature annealing
- 2009
-
Ingår i: Journal of Vacuum Science & Technology B. - : American Vacuum Society. - 1071-1023 .- 1520-8567 .- 2166-2754 .- 2166-2746. ; 27:1, s. 249-252
-
Tidskriftsartikel (refereegranskat)abstract
- The authors report on the investigation of amorphous Gd-based silicates as high-k dielectrics. Two different stacks of amorphous gadolinium oxide (Gd(2)O(3)) and silicon oxide (SiO(2)) on silicon substrates are compared after annealing at temperatures up to 1000 degrees C. Subsequently formed metal oxide semiconductor capacitors show a significant reduction in the capacitance equivalent thicknesses after annealing. Transmission electron microscopy, medium energy ion scattering, and x-ray diffraction analysis reveal distinct structural changes such as consumption of the SiO(2) layer and formation of amorphous Gd silicate. The controlled formation of Gd silicates in this work indicates a route toward high-k dielectrics compatible with conventional, gate first complementary metal-oxide semiconductor integration schemes.
|
|
| 15. |
|
|
| 16. |
- Hermansson, Liselotte, 1954-, et al.
(författare)
-
Psychosocial adjustment in Swedish children with upper-limb reduction deficiency and a myoelectric prosthetic hand
- 2005
-
Ingår i: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227. ; 94:4, s. 479-88
-
Tidskriftsartikel (refereegranskat)abstract
- AIM: To study psychosocial adjustment and mental health in children with upper-limb reduction deficiency and a myoelectric prosthetic hand.METHODS: Sixty-two parents of children aged 8 to 18 y old answered a questionnaire concerning competence and behaviour/emotional problems in their children. Of the 62 children, 37 adolescents aged 11 to 18 y old answered questionnaires concerning competence, problems and mood state. The results were compared with Swedish normative data. The children were divided into five groups based on degree of myoelectric prosthetic use.RESULTS: Children with upper-limb reduction deficiency and a myoelectric prosthetic hand showed social competence and behaviour/emotional problems similar to Swedish standardized norms. However, withdrawn behaviour was significantly higher in all children, social competence was significantly lower in girls, and social activities were significantly lower in older children with upper-limb reduction deficiency. There was a significant difference between prosthetic use groups. Non-users had significantly more delinquent behaviour problems than full-time users. There was an interaction between gender and prosthetic use in their affect on competence and behaviour/emotional problems, yielding two contrasting patterns.CONCLUSION: Children with upper-limb reduction deficiency and a myoelectric prosthetic hand are as well adjusted psychosocially as their able-bodied peers. There are indications, however, of social stigmata related to the deficiency, which have to be considered differently in boys and girls.
|
|
| 17. |
- Hulth, Stefan, 1965, et al.
(författare)
-
Nitrogen removal in marine environments: recent findings and future research challenges
- 2005
-
Ingår i: Marine Chemistry. - : Elsevier BV. - 0304-4203. ; 94:1-4, s. 125-145
-
Tidskriftsartikel (refereegranskat)abstract
- Respiratory reduction of nitrate (denitrification) is recognized as the most important process converting biologically available (fixed) nitrogen to N-2. In current N cycle models, a major proportion of global marine denitrification (50-70%) is assumed to take place on the sea floor, particularly in organic rich continental margin sediments. Recent observations indicate that present conceptual views of denitrification and pathways of nitrate reduction and N, formation are incomplete. Alternative N cycle pathways, particularly in sediments. include anaerobic ammonium oxidation to nitrite, nitrate and N-2 by Mn-oxides, and anaerobic ammonium oxidation coupled to nitrite reduction and subsequent N, mobilization. The discovery of new links and feedback mechanisms between the redox cycles of, e.g., C, N, S, Mn and Fe casts doubt on the present general understanding of the global N cycle. Recent models of the oceanic N budget indicate that total inputs are significantly smaller than estimated fixed N removal. The occurrence of alternative N reaction pathways further exacerbates the apparent imbalance as they introduce additional routes of N removal. In this contribution, we give a brief historical background of the conceptual understanding of N cycling in marine ecosystems, emphasizing pathways of aerobic and anaerobic N mineralization in marine sediments, and the implications of recently recognized metabolic pathways for N removal in marine environments. (c) 2004 Elsevier B.V. All rights reserved.
|
|
| 18. |
|
|
| 19. |
- Hurley, P.K., et al.
(författare)
-
Interface Defects in HfO2, LaSiOx, and Gd2O3 High-k/MetalGate Structures on Silicon
- 2008
-
Ingår i: J. Electrochem. Soc.. ; 155:2, s. G13-G20
-
Tidskriftsartikel (refereegranskat)abstract
- In this work, we present experimental results examining the energy distribution of the relatively high (>1×10^11 cm−2) electrically active interface defects which are commonly observed in high-dielectric-constant (high-k) metal–insulator–silicon systems during high-k process development. This paper extends previous studies on the Si(100)/SiOx/HfO2 system to include a comparative analysis of the density and energy distribution of interface defects for HfO2, lanthanum silicate (LaSiOx), and Gd2O3 thin films on (100) orientation silicon formed by a range of deposition techniques. The analysis of the interface defect density across the energy gap, for samples which experience no H2/N2 annealing following the gate stack formation, reveals a peak density (~2×10^12 cm−2 eV−1 to ~1×10^13 cm−2 eV−1) at 0.83–0.92 eV above the silicon valence bandedge for the HfO2, LaSiOx, and Gd2O3 thin films on Si(100). The characteristic peak in the interface state density (0.83–0.92 eV) is obtained for samples where no interface silicon oxide layer is observed from transmission electron microscopy. Analysis suggests silicon dangling bond (Pbo) centers as the common origin for the dominant interface defects for the various Si(100)/SiOx/high-k/metal gate systems. The results of forming gas (H2/N2) annealing over the temperature range 350–555°C are presented and indicate interface state density reduction, as expected for silicon dangling bond centers. The technological relevance of the results is discussed.
|
|
| 20. |
|
|
| 21. |
- Johansson, Linda C, 1983, et al.
(författare)
-
Membrane protein crystallization from lipidic phases
- 2009
-
Ingår i: Current Opinion in Structural Biology. - : Elsevier BV. - 0959-440X .- 1879-033X. ; 19:4, s. 372-378
-
Tidskriftsartikel (refereegranskat)abstract
- Membrane protein structural biology is enjoying a steady acceleration in the rate of success. Nevertheless, numerous membrane protein targets are resistant to the traditional approach of directly crystallizing detergent solubilized and purified protein and the 'niche market' of lipidic phase crystallization is emerging as a powerful complement. These approaches, including lipidic cubic phase, lipidic sponge phase, and bicelle crystallization methods, all immerse purified membrane protein within a lipid rich matrix before crystallization. This environment is hypothesized to contribute to the protein's long-term structural stability and thereby favor crystallization. Spectacular recent successes include the high-resolution structures of the beta(2)-adrenergic G-protein-coupled receptor, the A(2A) adenosine G-protein-coupled receptor, and the mitochondrial voltage dependent anion channel. In combination with technical innovations aiming to popularize these methods, lipidic phase crystallization approaches can be expected to deliver an increasing scientific impact as the field develops.
|
|
| 22. |
- Lu, Y., et al.
(författare)
-
Leakage current effects on C-V plots of high-k metal-oxide-semiconductor capacitors
- 2009
-
Ingår i: Journal of Vacuum Science & Technology B. - : American Vacuum Society. - 1071-1023 .- 1520-8567 .- 2166-2754 .- 2166-2746. ; 27:1, s. 352-355
-
Tidskriftsartikel (refereegranskat)abstract
- With the employment of ultrathin, high dielectric constant gate materials in advanced semiconductor technology, the conventional capacitance-voltage measurement technique exhibits a series of anomalies. In particular, a nonsaturating increase in the accumulation capacitance with reducing measurement frequency is frequently observed, which has not been adequately explained to our knowledge. In this article, the authors provide an explanation for this anomaly and hence set a criterion for the lower bound on measurement frequency. We then present a model which allows the easy extraction of the required parameters and apply it to an experimental set of data.
|
|
| 23. |
|
|
| 24. |
|
|
| 25. |
- Lundstedt, G., et al.
(författare)
-
Eating disorder traits in obese children and adolescents
- 2006
-
Ingår i: Eating and Weight Disorders. - 1124-4909 .- 1590-1262. ; 11:1, s. 45-50
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to investigate the prevalence of eating disorder (ED) traits among obese children and adolescents. The Swedish version of the Eating Disorder Inventory for Children, consisting of 11 subscales, was administered to 150 obese patients during an extensive investigation of causes and risk factors in obesity at the Karolinska University Hospital at Huddinge. Patients aged 17-18 years (N=24) had a mean body mass index (BMI) of 40.7, SD 5.31, and patients aged 8-16 (N=126) had a mean body mass index standard deviation score (BMI SDS) of 6.18, SD 1.69. These patients were compared with 201 girls with a diagnosed ED from the COEAT project and with a control group of schoolchildren. The comparison between obese girls and boys showed that adolescent obese girls scored higher than obese boys on Drive for Thinness, Bulimia and Body Dissatisfaction. They also scored higher on Ineffectiveness, Interoceptive Awareness and Impulse Regulation. Obese girls were close to the girls with an ED on six of the subscales. Obese boys had a lower score of Asceticism than boys in the control group. The conclusion is that psychological traits associated with disordered eating appear among obese patients, particularly among the girls. However, these patients rarely satisfy any diagnostic criteria for ED during childhood or adolescence. Since obesity treatment currently assumes rational behavior, i.e. no EDs, it is important to discover ED traits at an early age in order to adapt treatment accordingly.
|
|
| 26. |
|
|
| 27. |
|
|
| 28. |
- Moll, Henri C, et al.
(författare)
-
Pursuing More Sustainable Consumption by Analyzing Household Metabolism in European Countries and Cities
- 2005
-
Ingår i: Journal of Industrial Ecology. - : Wiley. - 1088-1980 .- 1530-9290. ; 9:1-2, s. 259-275
-
Tidskriftsartikel (refereegranskat)abstract
- Bringing about more sustainable consumption patterns is an important challenge for society and science. In this article the concept of household metabolism is applied to analyzing consumption patterns and to identifying possibilities for the development of sustainable household consumption patterns. Household metabolism is determined in terms of total energy requirements, including both direct and indirect energy requirements, using a hybrid method. This method enables us to evaluate various determinants of the environmental load of consumption consistently at several levels - the national level, the local level, and the household level. The average annual energy requirement of households varies considerably between the Netherlands, the United Kingdom, Norway, and Sweden, as well as within these countries. The average expenditure level per household explains a large part of the observed variations. Differences between these countries are also related to the efficiency of the production sectors and to the energy supply system. The consumption categories of food, transport, and recreation show the largest contributions to the environmental load. A comparison of consumer groups with different household characteristics shows remarkable differences in the division of spending over the consumption categories. Thus, analyses of different types of households are important for providing a basis for options to induce decreases of the environmental load of household consumption. At the city level, options for change are provided by an analysis of the city infrastructure, which determines a large part of the direct energy use by households (for transport and heating). At the national level, energy efficiency in production and in electricity generation is an important trigger for decreasing household energy requirements
|
|
| 29. |
- Nilsson, C U, et al.
(författare)
-
Effects of recombinant human activated protein C on the coagulation system: a study with rotational thromboelastometry.
- 2008
-
Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172. ; 52:9, s. 1246-1249
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Recombinant human activated protein C (rhAPC) is an anticoagulant that can be used for treatment of patients with severe sepsis. The use of rhAPC is accompanied by an increased risk of severe bleeding. Rotational thromboelastometry is a method for measuring the status of the coagulation. The aim of the study was to investigate whether rotational thromboelastometry could be used for monitoring the effects of rhAPC on the coagulation. METHODS: Whole blood was mixed in vitro with concentrations of rhAPC ranging from 0 to 75 ng/ml and analysed with rotational thromboelastometry. RESULTS: The parameter Coagulation Time was significantly prolonged by increasing the concentrations of rhAPC (P=0.002). Other parameters were not significantly affected. CONCLUSION: rhAPC dose dependently affects the early humoral parts of the coagulation, while platelet function and fibrinogen to fibrin conversion seem virtually unaffected.
|
|
| 30. |
|
|
| 31. |
- Raeissi, Bahman, 1979, et al.
(författare)
-
High-k-oxide/silicon interfaces characterized by capacitance frequency spectroscopy
- 2007
-
Ingår i: ESSDERC 2007. - 9781424411238 ; , s. 283-286
-
Konferensbidrag (refereegranskat)abstract
- Electron capture into insulator/silicon interface states is investigated for high-k dielectrics of Gd(2)O(3) prepared by MBE and ALD, and for HfO(2) prepared by reactive sputtering, by measuring the frequency dependence of MOS capacitance. The capture cross sections are found to be thermally activated and to increase steeply with the energy depth of the interface electron states. The methodology adopted is considered useful for increasing the understanding of high-k-oxide/silicon interfaces.
|
|
| 32. |
- Raeissi, Bahman, 1979, et al.
(författare)
-
High-k-oxide/silicon interfaces characterized by capacitance frequency spectroscopy
- 2008
-
Ingår i: Solid-State Electronics. - : Elsevier BV. - 0038-1101 .- 1879-2405. ; 52:9, s. 1274-1279
-
Tidskriftsartikel (refereegranskat)abstract
- Electron capture into insulator/silicon interface states is investigated for high-k dielectrics of Gd2O3 preparedby molecular beam epitaxy (MBE) and atomic layer deposition (ALD), and for HfO2 prepared byreactive sputtering, by measuring the frequency dependence of Metal Oxide Semiconductor (MOS) capacitance.The capture cross sections are found to be thermally activated and to increase steeply with theenergy depth of the interface electron states. The methodology adopted is considered useful for increasingthe understanding of high-k-oxide/silicon interfaces.
|
|
| 33. |
|
|
| 34. |
- Reynolds, Ben C., et al.
(författare)
-
An inter-laboratory comparison of Si isotope reference materials
- 2007
-
Ingår i: Journal of Analytical Atomic Spectrometry. - : Royal Society of Chemistry (RSC). - 0267-9477 .- 1364-5544. ; 22:5, s. 561-568
-
Tidskriftsartikel (refereegranskat)abstract
- Three Si isotope materials have been used for an inter-laboratory comparison exercise to ensure reproducibility between international laboratories investigating natural Si isotope variations using a variety of chemical preparation methods and mass spectrometric techniques. These proposed standard reference materials are (i) IRMM-018 (a SiO2 standard), (ii) Big-Batch (a fractionated SiO2 material prepared at the University of California Santa Barbara), and (iii) Diatomite (a natural diatomite sample originally deposited as marine biogenic opal). All analyses are compared with the international Si standard NBS28 (RM8546) and are in reasonable agreement (<+/- 0.22 parts per thousand. 1 sigma(SD) delta Si-30) given the different measurement techniques involved. These methods include both acid and alkaline dissolution/fusion, Si separation using cation exchange, selective co-precipitation, and gas-source versus plasma-ionization (high and low resolution) mass-spectrometric techniques. The average delta Si-30 for Diatomite, IRMM-018, and Big-Batch are + 1.26 parts per thousand, -1.65 parts per thousand and -10.48 parts per thousand, respectively, with corresponding delta Si-9 values of + 0.64 parts per thousand, -0.85 parts per thousand and -5.35 parts per thousand for the same standards, respectively. For the most fractionated standard (Big-Batch), results demonstrate a kinetic mass-dependent fractionation effect for atomic Si (i.e., delta Si-29 similar to 0.51 x delta Si-30). There is almost no statistical difference between the mean values obtained by each participating laboratory, with the notable exception of the IRMM-018 standard. This effect could be caused by heterogeneity or contamination of this standard. The results for the other two standards indicate that data sets produced using any of the methods employed in this study will have similar precision and differences are limited to 0.2 parts per thousand in mean delta Si-30 values for a given sample between laboratories, or differences of 0.13 parts per thousand. in mean delta Si-29 values.
|
|
| 35. |
- Reynolds, Ben C., et al.
(författare)
-
An inter-laboratory comparison of Si isotope reference materials
- 2007
-
Ingår i: Journal of Analytical Atomic Spectrometry. - : Elsevier BV. - 0267-9477 .- 1364-5544. ; 22:5, s. 561-568
-
Tidskriftsartikel (refereegranskat)abstract
- Three Si isotope materials have been used for an inter-laboratory comparison exercise to ensure reproducibility between international laboratories investigating natural Si isotope variations using a variety of chemical preparation methods and mass spectrometric techniques. These proposed standard reference materials are (i) IRMM-018 (a SiO2 standard), (ii) Big-Batch (a fractionated SiO2 material prepared at the University of California Santa Barbara), and (iii) Diatomite (a natural diatomite sample originally deposited as marine biogenic opal). All analyses are compared with the international Si standard NBS28 (RM8546) and are in reasonable agreement (<+/- 0.22 parts per thousand. 1 sigma(SD) delta Si-30) given the different measurement techniques involved. These methods include both acid and alkaline dissolution/fusion, Si separation using cation exchange, selective co-precipitation, and gas-source versus plasma-ionization (high and low resolution) mass-spectrometric techniques. The average delta Si-30 for Diatomite, IRMM-018, and Big-Batch are + 1.26 parts per thousand, -1.65 parts per thousand and -10.48 parts per thousand, respectively, with corresponding delta Si-9 values of + 0.64 parts per thousand, -0.85 parts per thousand and -5.35 parts per thousand for the same standards, respectively. For the most fractionated standard (Big-Batch), results demonstrate a kinetic mass-dependent fractionation effect for atomic Si (i.e., delta Si-29 similar to 0.51 x delta Si-30). There is almost no statistical difference between the mean values obtained by each participating laboratory, with the notable exception of the IRMM-018 standard. This effect could be caused by heterogeneity or contamination of this standard. The results for the other two standards indicate that data sets produced using any of the methods employed in this study will have similar precision and differences are limited to 0.2 parts per thousand in mean delta Si-30 values for a given sample between laboratories, or differences of 0.13 parts per thousand. in mean delta Si-29 values.
|
|
| 36. |
- Sitch, Stephen, et al.
(författare)
-
Assessing the carbon balance of circumpolar Arctic tundra using remote sensing and process modeling
- 2007
-
Ingår i: Ecological Applications. - : John Wiley & Sons. - 1051-0761 .- 1939-5582. ; 17:1, s. 213-234
-
Tidskriftsartikel (refereegranskat)abstract
- This paper reviews the current status of using remote sensing and process-based modeling approaches to assess the contemporary and future circumpolar carbon balance of Arctic tundra, including the exchange of both carbon dioxide and methane with the atmosphere. Analyses based on remote sensing approaches that use a 20-year data record of satellite data indicate that tundra is greening in the Arctic, suggesting an increase in photosynthetic activity and net primary production. Modeling studies generally simulate a small net carbon sink for the distribution of Arctic tundra, a result that is within the uncertainty range of field-based estimates of net carbon exchange. Applications of processbased approaches for scenarios of future climate change generally indicate net carbon sequestration in Arctic tundra as enhanced vegetation production exceeds simulated increases in decomposition. However, methane emissions are likely to increase dramatically, in response to rising soil temperatures, over the next century. Key uncertainties in the response of Arctic ecosystems to climate change include uncertainties in future fire regimes and uncertainties relating to changes in the soil environment. These include the response of soil decomposition and respiration to warming and deepening of the soil active layer, uncertainties in precipitation and potential soil drying, and distribution of wetlands. While there are numerous uncertainties in the projections of process-based models, they generally indicate that Arctic tundra will be a small sink for carbon over the next century and that methane emissions will increase considerably, which implies that exchange of greenhouse gases between the atmosphere and Arctic tundra ecosystems is likely to contribute to climate warming.
|
|
| 37. |
- Snir, O., et al.
(författare)
-
Multiple antibody reactivities to citrullinated antigens in sera from patients with rheumatoid arthritis : association with HLA-DRB1 alleles
- 2009
-
Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 68:5, s. 736-743
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Autoantibodies to cyclic citrullinated peptides (anti-CCP) are present in most patients with rheumatoid arthritis ( RA), and associate with HLA-DRB1 shared epitope (SE) alleles. Objective: To investigate reactivities of anti-CCP to various citrullinated proteins/peptides, which represent potential autoantigens in RA, and to examine the relationship between such antibodies, and their association with genetic variants within HLA-DRB1 SE alleles. Methods: Serum samples from 291 patients with established RA and 100 sex- and age-matched healthy subjects were included in this study. Sera were first analysed for presence of anti-CCP antibodies and further for IgG and IgA antibodies towards candidate autoantigens in both their native and citrullinated form including: fibrinogen, alpha-enolase peptide-1 and the C1-epitope of type II collagen (C1(III)). Antibody specificity was confirmed by cross-reactivity tests. HLA-DR genotyping was performed. Results: 72% of patients with RA were anti-CCP positive. Among the candidate autoantigens examined, IgG antibodies to citrullinated fibrinogen were found in 66% of patients' sera and in 41% for both citrullinated alpha-enolase peptide-1 and citrullinated C1(III). These antibodies were mainly seen in the anti-CCP-positive patient group; they were specific for their respective antigen and displayed limited cross reactivity. IgA responses were also detected, but less frequently than IgG. Anti-CCP and anti-citrullinated protein antibodies were associated with HLA-DRB1*04 rather than with HLA-DRB1*01 alleles. Conclusions: Antibodies directed against several citrullinated antigens are present in CCP-positive RA, with many patients displaying multireactivity. All specific reactivities were primarily associated with the HLA-DRB1*04 alleles, suggesting common pathways of anti-citrulline immunity.
|
|
| 38. |
|
|
| 39. |
|
|
| 40. |
- Warner, C., et al.
(författare)
-
A vestibular diagnostic : Balance platform
- 2005
-
Ingår i: Proceedings of the Third IASTED International Conference on Biomedical Engineering. - Anaheim, CA : IASTED/Acta Press. - 0889864780 ; , s. 405-409
-
Konferensbidrag (refereegranskat)abstract
- The control of balance is achieved mainly through the integration of information coming from the vestibular organs in each ear. The extent of its control is recognized when dysfunctions of the vestibular system occur. This is seen in the abrupt dizziness of Meniere's disease, which is related to the imbalance of input between the two vestibular systems [1]. To determine the deterioration of vestibular function or to demonstrate the efficacy of therapeutic or drug interventions on the vestibular system, a prototype method of the ongoing assessment of balance disorder was developed. The system uses a wavelet decomposition of a balance plate recording to find the frequency content of healthy and balance impaired subjects during a variety of balancing tasks. Two main frequency bands (3-9Hz and 11-16Hz) were observed as likely components reflecting vestibular health
|
|
| 41. |
- Wöhri, Annemarie, 1976, et al.
(författare)
-
A Lipidic-Sponge Phase Screen for Membrane Protein Crystallization
- 2008
-
Ingår i: Structure. - : Elsevier BV. - 0969-2126 .- 1878-4186. ; 16:7, s. 1003-1009
-
Tidskriftsartikel (refereegranskat)abstract
- A major current deficit in structural biology is the lack of high-resolution structures of eukaryotic membrane proteins, many of which are key drug targets for the treatment of disease. Numerous eukaryotic membrane proteins require specific lipids for their stability and activity, and efforts to crystallize and solve the structures of membrane proteins that do not address the issue of lipids frequently end in failure rather than success. To help address this problem, we have developed a sparse matrix crystallization screen consisting of 48 lipidic-sponge phase conditions. Sponge phases form liquid lipid bilayer environments which are suitable for conventional hanging- and sitting-drop crystallization experiments. Using the sponge phase screen, we obtained crystals of several different membrane proteins from bacterial and eukaryotic sources. We also demonstrate how the screen may be manipulated by incorporating specific lipids such as cholesterol; this modification led to crystals being recovered from a bacterial photosynthetic core complex.
|
|
| 42. |
- Öhlén, Joakim, 1958-, et al.
(författare)
-
Kommentar till kunskapssammanställningen
- 2007
-
Ingår i: Patientundervisning och patienters lärande. - Stockholm : Gothia Förlag AB. - 9789172055162 ; , s. 41-45
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
|
|
