High power photon collimators for the ILC.

An undulator-based source has been chosen as a part of the baseline configuration for the International Linear Collider (ILC) to generate an intense beam of polarised positrons. A photon collimator placed between the undulator and the target can be used to adjust the size, intensity and polarisation of the photon beam impacting the target, and can also protect the target station and limit the activation of downstream components. In this paper, we calculate quantities such as the energy deposition, temperature change, activation and dose rate for different designs of the photon collimator, and consider the advantages and disadvantages for each case

Progenitor cells are responsible for formation of human prostate epithelium primary cultures

To analyze cell viability and morphology of primary cell cultures from CD133 immunolabeled and sorted cells from epithelium of patients suffering from benign prostate hyperplasia (BPH). Methods: Cells obtained from 5 patients were divided in two fractions. First fraction (CD133+/CD133–) was cultivated in DMEM with 10% FBS. Second fraction was mixed with CD133 microbeads and immunomagnetically divided into CD133+ and CD133– fractions. These cells were cultivated and followed-up for 2 weeks. Cells were stained for Annexin V FITC/propidium iodide. Results: Seventy CD133+/CD133– cultures, thirty-one of CD133+ and thirty-one of CD133– cells were established. There were 5-fold and 3-fold increase of CD133+/CD133- and CD133+ cell number after 2 weeks, respectively. CD133+/CD133– and CD133+ monolayers displayed epithelial-like morphology and cytokeratine expression. CD133– cultures collapsed. Cell viability within CD133+ and CD133– populations was 90.1 ± 6.3% and 24.3 ± 6.2%, respectively. Apoptotic index was 9.0 ± 6.1% and 28.5 ± 23.8% within CD133+ and CD133– cultures, respectively. Conclusions: CD133 separated human primary epithelial cell cultures displayed differences in morphology, viability and apoptosis occurrence. Immunomagnetic sorting can be recommended in each in vitro experiments with primary cell cultures in order to provide more objective results.Цель: оценить жизнеспособность и морфологию клеток первичных клеточных культур, полученных из меченных по CD133 и полученных с помощью клеточной сортировки клеток эпителия пациентов с доброкачественной гиперплазией предстательной железы (BPH). Методы: клетки, полученные от 5 пациентов, были разделены на 2 фракции. Первую фракцию (CD133+/CD133–) выращивали в DMEM с 10% FBS али с CD133 магнитными гранулами и с помощью магнита разделили клетки на CD133+- и CD133–-фракции. Далее клетки культивировали в течении 2 нед. Клетки окрашивали аннексиномV FITC/пропидий йодидом. Результаты: получено 70 CD133+/CD133- -культур клеток, 31 CD133+ и 31 CD133–. Через 2 нед культивирования отмечали 5-кратное и 3-кратное увеличение количества CD133+/CD133– и CD133+ клеток соответственно. CD133+/CD133- -и CD133+-клетки росли в монослое и имели морфологию эпителиальных клеток, экспрессировали цитокератин. CD133–-клетки не выжили. Выживаемость клеток в популяциях CD133+ и CD133– была 90,1 ± 6,3% и 24,3 ± 6,2% соответственно. Показатель апоптического индекса для культур CD133+ и CD133– был 9,0 ± 6,1% и 28,5 ± 23,8% соответственно. Выводы: показаны различия в морфологии, выживаемости клеток и частоте апоптоза для эпителиальных клеток, разделенных в зависимости от экспрессии CD133. Сортировка клеток с помощью иммуномагнитного разделения рекомендована для каждого in vitro эксперимента с использованием первичных клеточных культур для получения более объективных результатов

A mutational analysis of the globotriaosylceramide-binding sites of verotoxin VT1.

Escherichia coli verotoxin, also known as Shiga-like toxin, binds to eukaryotic cell membranes via the glycolipid Gb(3) receptors which present the P(k) trisaccharide Galalpha(1-4)Galbeta(1-4)Glcbeta. Crystallographic studies have identified three P(k) trisaccharide (P(k)-glycoside) binding sites per verotoxin 1B subunit (VT1B) monomer while NMR studies have identified binding of P(k)-glycoside only at site 2. To understand the basis for this difference, we studied binding of wild type VT1B and VT1B mutants, defective at one or more of the three sites, to P(k)-glycoside and pentavalent P(k) trisaccharide (pentaSTARFISH) in solution and Gb(3) presented on liposomal membranes using surface plasmon resonance. Site 2 was the key site in terms of free trisaccharide binding since mutants altered at sites 1 and 3 bound this ligand with wild type affinity. However, effective binding of the pentaSTARFISH molecule also required a functional site 3, suggesting that site 3 promotes pentavalent binding of linked trisaccharides at site 1 and site 2. Optimal binding to membrane-associated Gb(3) involved all three sites. Binding of all single site mutants to liposomal Gb(3) was weaker than wild type VT1B binding. Site 3 mutants behaved as if they had reduced ability to enter into high avidity interactions with Gb(3) in the membrane context. Double mutants at site 1/site 3 and site 2/site 3 were completely inactive in terms of binding to liposomal Gb(3,) even though the site 1/site 3 mutant bound trisaccharide with almost wild type affinity. Thus site 2 alone is not sufficient to confer high avidity binding to membrane-localized Gb(3). Cytotoxic activity paralleled membrane glycolipid binding. Our data show that the interaction of verotoxin with the Gb(3) trisaccharide is highly context dependent and that a membrane environment is required for biologically relevant studies of the interaction

Transverse phase space characterization in an accelerator test facility

We compare three techniques for characterising the transverse phase space distribution of the beam in CLARA FE (the Compact Linear Accelerator for Research and Applications Front End, at Daresbury Laboratory, UK): emittance and optics measurements using screens at three separate beamline locations; quadrupole scans; and phase space tomography. We find that where the beam distribution has significant structure (as in the case of CLARA FE at the time the measurements presented here were made) tomography analysis is the most reliable way to obtain a meaningful characterisation of the transverse beam properties. We present the first experimental results from four-dimensional phase space tomography: our results show that this technique can provide an insight into beam properties that are of importance for optimising machine performance

Transverse phase space tomography in the CLARA accelerator test facility using image compression and machine learning

We describe a novel technique, based on image compression and machine learning, for transverse phase space tomography in two degrees of freedom in an accelerator beamline. The technique has been used in the CLARA accelerator test facility at Daresbury Laboratory: results from the machine learning method are compared with those from a conventional tomography algorithm (algebraic reconstruction), applied to the same data. The use of machine learning allows reconstruction of the 4D phase space distribution of the beam to be carried out much more rapidly than using conventional tomography algorithms, and also enables the use of image compression to reduce significantly the size of the data sets involved in the analysis. Results from the machine learning technique are at least as good as those from the algebraic reconstruction tomography in characterising the beam behaviour, in terms of the variation of the beam size in response to variation of the quadrupole strengths