| 1. |
- Dutta, D, et al.
(författare)
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Nuclear transparency with the gamma n ->pi(-)p process in He-4
- 2003
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 68:2: 021001
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Tidskriftsartikel (refereegranskat)abstract
- We have measured the nuclear transparency of the fundamental process gamman-->pi(-)p in He-4. These measurements were performed at Jefferson Lab in the photon energy range of 1.6-4.5 GeV and at theta(cm)(pi)=70degrees and 90degrees. These measurements are the first of their kind in the study of nuclear transparency in photoreactions. They also provide a benchmark test of Glauber calculations based on traditional models of nuclear physics. The transparency results suggest deviations from the traditional nuclear physics picture. The momentum transfer dependence of the measured nuclear transparency is consistent with Glauber calculations that include the quantum chromodynamics phenomenon of color transparency.
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| 2. |
- Zhu, LY, et al.
(författare)
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Cross-section measurement of charged-pion photoproduction from hydrogen and deuterium
- 2003
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Ingår i: Physical Review Letters. - 1079-7114. ; 91:2: 022003
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Tidskriftsartikel (refereegranskat)abstract
- We have measured the differential cross section for the gamman-->pi(-)p and gammap-->pi(+)n reactions at theta(c.m.)=90degrees in the photon energy range from 1.1 to 5.5 GeV at Jefferson Lab (JLab). The data at E(gamma)greater than or similar to3.3 GeV exhibit a global scaling behavior for both pi(-) and pi(+) photoproduction, consistent with the constituent counting rule and the existing pi(+) photoproduction data. Possible oscillations around the scaling value are suggested by these new data. The data show enhancement in the scaled cross section at a center-of-mass energy near 2.2 GeV. The cross section ratio of exclusive pi(-) to pi(+) photoproduction at high energy is consistent with the prediction based on one-hard-gluon-exchange diagrams.
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| 3. |
- Andersson, Roland, et al.
(författare)
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Preoperative staging and evaluation of resectability in pancreatic ductal adenocarcinoma.
- 2004
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Ingår i: HPB. - : Elsevier BV. - 1477-2574 .- 1365-182X. ; 6:1, s. 5-12
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cancer of the pancreas is a common disease, but the large majority of patients have tumours that are irresectable at the time of diagnosis. Moreover, patients whose tumours are clearly beyond surgical cure are best treated non-operatively, if possible, by relief of biliary obstruction and percutaneous biopsy to confirm the diagnosis and then consideration of oncological treatment, notably chemotherapy. These facts underline the importance of a standard protocol for the preoperative determination of operability (is it worth operating?) and resectability (is there a chance that the tumour can be removed?). Recent years have seen the advent of many new techniques, both radiological and endoscopic, for the diagnosis and staging of pancreatic cancer. It would be impracticable in time and cost to submit every patient to every test. This review will evaluate the available techniques and offer a possible algorithm for use in routine clinical practice. DISCUSSION: In deciding whether to operate with a view to resecting a pancreatic cancer, the surgeon must take into account factors related to the patient, the tumour and the institution and team entrusted with the patient's care. Patient-related factors include age, general health, pain and the presence or absence of malnutrition and an acute phase inflammatory response. Tumour-related factors include tumour size and evidence of spread, whether to adjacent organs (notably major blood vessels) or further afield. Hospital-related factors chiefly concern the volume of pancreatic cancer treated and thus the experience of the whole team. Determination of resectability is heavily dependent upon detailed imaging. Nowadays conventional ultrasonography can be supplemented by endoscopic, laparoscopic and intra-operative techniques. Computed tomography (CT) remains the single most useful staging modality, but MRI continues to improve. PET scanning may demonstrate unsuspected metastases and likewise laparoscopy. Diagnostic cholangiography can be performed more easily by MR techniques than by endoscopy, but ERCP is still valuable for preoperative biliary decompression in appropriate patients. The role of angiography has declined. Percutaneous biopsy and peritoneal cytology are not usually required in patients with an apparently resectable tumour. The prognostic value of tumour marker levels and bone marrow biopsy is yet to be established. Preoperative chemotherapy or chemoradiation may have a role in down-staging an irresectable tumour sufficiently to render it resectable. Selective use of diagnostic laparoscopy staging is potentially helpful in determination of resectability. Laparotomy remains the definitive method for determining the resectability of pancreatic cancer, with or without portal vein resection, and should be undertaken in suitable patients without clear-cut evidence of irresectability.
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| 7. |
- Tay, GK, et al.
(författare)
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PERB11 (MIC) : a polymorphic MHC gene is expressed in skin and single nucleotide polymorphisms are associated with psoriasis.
- 2000
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Ingår i: Clinical and Experimental Immunology. - : John Wiley & Sons. - 0009-9104 .- 1365-2249. ; 119:3, s. 553-558
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Tidskriftsartikel (refereegranskat)abstract
- The susceptibility genes for psoriasis remain to be identified. At least one of these must be in the major histocompatibility complex (MHC) to explain associations with alleles at human leucocyte antigen (HLA)-A, -B, -C, -DR, -DQ and C4. In fact, most of these alleles are components of just two ancestral haplotypes (AHs) designated 13.1 and 57.1. Although relevant MHC gene(s) could be within a region of at least 4 Mb, most studies have favoured the area near HLA-B and -C. This region contains a large number of non-HLA genes, many of which are duplicated and polymorphic. Members of one such gene family, PERB11.1 and PERB11.2, are expressed in the skin and are encoded in the region between tumour necrosis factor and HLA-B. To investigate the relationship of PERB11.1 alleles to psoriasis, sequence based typing was performed on 97 patients classified according to age of onset and family history. The frequency of the PERB11.1*06 allele is 44% in type I psoriasis but only 7% in controls (Pc = 0.003 by Fisher's exact test, two-tailed). The major determinant of this association is a single nucleotide polymorphism (SNP) within intron 4. In normal and affected skin, expression of PERB11 is mainly in the basal layer of the epidermis including ducts and follicles. PERB11 is also present in the upper keratin layers but there is relative deficiency in the intermediate layers. These findings suggest a possible role for PERB11 and other MHC genes in the pathogenesis of psoriasis.
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