| 1. |
- Shrestha, Sarita, 1991-, et al.
(författare)
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The use of ICD codes to identify IBD subtypes and phenotypes of the Montreal classification in the Swedish National Patient Register
- 2020
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 55:4, s. 430-435
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Whether data on International Classification of Diseases (ICD)-codes from the Swedish National Patient Register (NPR) correctly correspond to subtypes of inflammatory bowel disease (IBD) and phenotypes of the Montreal classification scheme among patients with prevalent disease is unknown. Materials and methods: We obtained information on IBD subtypes and phenotypes from the medical records of 1403 patients with known IBD who underwent biological treatment at ten Swedish hospitals and retrieved information on their IBD-associated diagnostic codes from the NPR. We used previously described algorithms to define IBD subtypes and phenotypes. Finally, we compared these register-generated subtypes and phenotypes with the corresponding information from the medical records and calculated positive predictive values (PPV) with 95% confidence intervals. Results: Among patients with clinically confirmed disease and diagnostic listings of IBD in the NPR (N = 1401), the PPV was 97 (96-99)% for Crohn's disease, 98 (97-100)% for ulcerative colitis, and 8 (4-11)% for IBD-unclassified. The overall accuracy for age at diagnosis was 95% (when defined as A1, A2, or A3). Examining the validity of codes representing disease phenotype, the PPV was 36 (32-40)% for colonic Crohn's disease (L2), 61 (56-65)% for non-stricturing/non-penetrating Crohn's disease behaviour (B1) and 83 (78-87)% for perianal disease. Correspondingly, the PPV was 80 (71-89)% for proctitis (E1)/left-sided colitis (E2) in ulcerative colitis. Conclusions: Among people with known IBD, the NPR is a reliable source of data to classify most subtypes of prevalent IBD, even though misclassification commonly occurred in Crohn's disease location and behaviour and also among IBD-unclassified patients.
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| 2. |
- Bengtsson, Jonas, 1961, et al.
(författare)
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Can a failed ileal pouch anal anastomosis be left in situ?
- 2007
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Ingår i: Colorectal disease. - : Wiley. - 1462-8910 .- 1463-1318. ; 9:6, s. 503-8
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Failure after ileal pouch-anal anastomosis (IPAA) is reported with a frequency of 10-20%. The failed IPAA can be excised or defunctioned. Indications for excision and further management of an indefinitely diverted pouch are poorly described. The aim of the present investigation was to investigate pouch-related problems and the histopathological pattern of the pouch mucosa in this group of patients. METHOD: In a cohort of 620 patients having IPAA with a median follow-up of 14 years, 56 patients with failure were identified. The patients with defunctioned pouches were assessed with regard to pouch-related problems and endoscopy with biopsies was performed. Biopsies were stained with haematoxylin-eosin, PAS for neutral mucins and Alcian blue/high iron diamine for sialomucins/sulphomucins. Morphological changes were grouped into three types modified according to Veress and assessed for dysplasia. RESULTS: Twenty-two patients with an indefinitely diverted pouch were found. The follow-up time after surgery for failure was 10 years. Thirteen patients completed the follow-up. Except for two patients with pelvic/perineal pain, there were no clinical problems. The majority of patients displayed mild to moderate macroscopic signs of inflammation. Morphologically, findings ranged from a preserved mucosal pattern to intense inflammatory reaction. No case of dysplasia or carcinoma was found. CONCLUSION: Most patients with an indefinitely diverted pouch had no complaints regarding the pouch. There was no case of dysplasia. Indefinite diversion may be preferable to pouch excision, especially given the associated morbidity.
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| 3. |
- Bengtsson, Jonas, 1961, et al.
(författare)
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Long-term function and manovolumetric characteristics after ileal pouch-anal anastomosis for ulcerative colitis
- 2007
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Ingår i: The British journal of surgery. - : Oxford University Press (OUP). - 0007-1323 .- 1365-2168. ; 94:3, s. 327-32
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Long-term pouch function and physiological characteristics after ileal pouch-anal anastomosis (IPAA) are poorly described. The aim of this study was to undertake a prospective investigation of long-term pouch function and manovolumetric characteristics. METHODS: Forty-two patients with a median follow-up of 16 years after IPAA were included. Function was assessed using a questionnaire and a score was calculated ranging from 0 to 15 (15 being the worst). Manovolumetry was performed and pouchitis recorded. A paired analysis was conducted, as the results were compared with previous data for each patient. RESULTS: The median functional score was 3.5 (range 0-10) at 2 years and 5 (range 1-11) at 16 years (P = 0.013). Resting anal canal pressures were higher (P < 0.001) and squeeze pressures lower (P = 0.008) at long-term follow-up. Ileal pouch volumes at distension pressures of 10, 20 and 40 cm H(2)O were diminished at 16 years (P < 0.001, P = 0.005 and P = 0.058 respectively). The volume and pressure for first sensation and urge to defaecate were reduced. Increased age correlated positively with a poor functional score. A history of pouchitis did not affect functional or physiological characteristics. CONCLUSION: Ileal pouch function declines in the long term. The reasons are unclear, but the ageing process may have an impact.
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| 4. |
- Berg, Jonas, 1973, et al.
(författare)
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A study on integration of molecular devices into CMOS compatible technology
- 2004
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Ingår i: Physica Scripta. - 1402-4896 .- 0031-8949. ; T114, s. 175-180
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Tidskriftsartikel (refereegranskat)abstract
- One main obstacle for measuring matter at the level of single molecule is the technology to make a bridge between molecules and microscopic structures (electrodes). A method of fabricating vertical silicon based nanogaps for contacting nanoscale elements has been developed and exploited to confront this problem. The developed technique is compatible to existing CMOS fabrication technology, reproducible and the gap size is easy to measure by simple capacitance measurements. Chemical treatment to attach any kind of nanoscale elements into the nanogap is an important issue. In this paper, we address problems related to surface leakage induced from different chemical processes. We have studied the effects of solvents on the surface leakage as well as surface leakage induced by nano components themselves. Surface leakage is a diffusion current process, and a set of parameters describing it has been used to compare the influence from different chemical processes. The study on solvents confirmed no predominant surface leakage induced by the presence of solvents like toluene and chloroform.
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| 5. |
- Berg, Jonas, 1973, et al.
(författare)
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Analysis of the use of molecular resonant tunneling diodes for local refresh of dynamic random access memory cells
- 2001
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Ingår i: MRS Spring Meeting. ; 679E, s. B1.6-
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Konferensbidrag (refereegranskat)abstract
- Simulations have been made to analyze the use of molecular resonant tunneling diodes for local refresh of DRAM (Dynamic Random Access Memory) cells. Local refresh can be provided by a latch consisting of a pair of resonant tunneling diodes connected to the storage capacitor of the cell. Such a solution would significantly reduce the standby power consumption of the DRAM cell. We have compared the requirements on the resonant tunneling diodes for proper refresh operation with the electrical properties of published molecules with resonant IV-curves. The simulations show that no molecules with resonant electrical properties published so far in the literature have properties making them useful for this particular application. This is true also for low temperature operation. The issues of maximum tolerable series resistance and of maximum tolerable fluctuations in the number of attached molecules have also been addressed. Our results show that the focus for development of molecules with resonant electrical properties should be to find molecules with resonance for lower applied voltages and lower current levels than the molecules published so far. If the synthesis of new molecules with attractive properties is successful the merging of silicon technology and molecular electronics, for instance for new generations of DRAM cells, is a realistic future path of microelectronics.
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| 6. |
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| 7. |
- Berg, Jonas, 1973, et al.
(författare)
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Can molecular resonant tunneling diodes be used for local refresh of DRAM memory cells?
- 2001
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Ingår i: 7th MELARI/NID workshop.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The use of molecular resonant tunneling diodes (RTDs) for use as local refresh of low-power DRAM cells has been studied. A pair of RTDs connected to the cell forms a latch that provides local refresh. This reduces the standby power of the cell, as the refresh operation is very power consuming. In this work, we compare the demands of future DRAM generations with the electrical properties of published molecules showing negative differential resistance. Simulations show that no one of the so far published molecular RTDs, other low-current RTDs made in SiGe, or III-V-materials fulfill these requirements.The simulations show that the focus of molecule development should be to find molecules with resonance for lower applied voltages and with lower current levels in general. The issues of maximum tolerable series resistance in the connection between the molecules and the silicon, and the maximum tolerable fluctuations in the number of attached molecules are also addressed.
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| 8. |
- Berg, Jonas, 1973, et al.
(författare)
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Electrical Properties of Si-SiO2-Si Nanogaps
- 2005
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Ingår i: Nanotechnology. - : IOP Publishing. - 1361-6528 .- 0957-4484. ; 16:10, s. 2197-2202
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Tidskriftsartikel (refereegranskat)abstract
- The chances of attaching organic molecules to silicon surfaces can be considerably enhanced if a robust nanogap structure with silicon electrodes can be used to connect the molecules. We describe the electrical properties of such an electrode structure, with a separation of the silicon surfaces in the 37 nm range. These silicon nanogaps are manufactured by partly removing the silicon dioxide insulator from a siliconoxidesilicon material stack, by using a selective oxide etchant. After the activation of the gap (the etching), current instabilities appear, which are comparable to the properties of thin oxides after soft breakdown. Applying a constant voltage can reduce these current instabilities. We also address the issue of surface leakage currents for these nanogap structures.
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| 9. |
- Berg, Jonas, 1973, et al.
(författare)
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Low-frequency noise in silicon nanogaps
- 2005
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 87:21, s. 223107-3
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Tidskriftsartikel (refereegranskat)abstract
- Silicon nanogaps are contact structures for connecting organic molecules. An insulating layer is removed by etching, and this dramatically increases the current levels and the noise, which closely resembles a 1/f-law and scales with the square of the current. After etching the noise level at 30 Hz and 10 nA is in the order of 10-21 A2/Hz, which is more than two orders of magnitude larger than before etching. We model the noisy behavior by several percolation paths in parallel at the etched surface between the electrodes, and compare with soft breakdown in thin oxide.
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| 10. |
- Berg, Jonas, 1973, et al.
(författare)
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Simulation of SOI MOSFETs at GHz frequencies
- 2000
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Ingår i: GHz 2000. ; , s. 399-402
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Silicon-on-Insulator (SOI) technology shows advantages over bulk silicon technology at high frequencies. In this work, the performance of SOI MOSFETs has been simulated at GHz frequencies for SOI materials of different substrate resistivities using the device simulator Atlas. The transistors with an effective channel length of 0.24 µm were assumed to be made in a fully depleted SOI material consisting of a 30 nm silicon film on top of 100 nm buried silicon dioxide on top of a silicon substrate. The substrate resistivity was varied from 0.01 Ohmcm to 10 kOhmcm. The simulated transistors had a maximum oscillation frequency (fmax) of approximately 62 GHz. It was found that the high frequency properties of intrinsic transistors were independent of the substrate resistivity, but a system consisting of both active and passive components showed reduced fmax and fT for low substrate resistivity.
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