Stability study of somatropin by capillary zone electrophoresis

Human Growth Hormone (hGH) is a monomeric 22 kilo Dalton (kDa), 191 amino acid protein with an isoelectric point (pI) close to pH 5, produced in the anterior pituitary gland. High level production of somatropin (recombinant hGH) is done in Escherichia coli (E. coli) to meet the demand and to avoid possible Creutzfeldt-Jacob disease (CJD).The present study was initiated on the basis of results from post-marketing control of all somatropin preparations on the Norwegian market. The samples consisted of preparations presented as somatropin in solution, and some freeze-dried preparations were also included for comparison.The present study showed a significant degree of degradation of somatropin in solution. Deamidation increased over time for preparations in solution, as well as for freeze-dried preparations after dissolution. Preparations in solution showed high content of deamidated and cleaved forms. Freeze-dried preparations after dissolution and storage showed high content of deamidated forms, but low content of cleaved forms. Also, in one preparation, an unknown peak was detected in the electropherogram from capillary zone electrophoresis (CZE), eluting after the principal peak, in front of the Gln-18 somatropin peak.     

Pionic Fusion Study of the halo analogue state6Li

The isobaric analogue state of the ground state of the halo nucleus⁶He,⁶Li* has been studied in a pionic fusion experiment at the CELSIUS storage ring facility in Uppsala, Sweden. This was the first of two proposed experiments with the aim to study the high momentum part of the wave functions of the halo nuclei⁶He and⁶Li (0⁺, T=1). The Li nuclei were produced in inverse kinematics reactions with alpha particles incident on a deuterium cluster jet target. The⁶Li ions were detected in a zero-degree spectrometer situated in the fourth quadrant of the CELSIUS ring. The measurement was done for three different beam energies corresponding to 5.4, 2.2 and 1.5 MeV above threshold in the c.m. The cross-sections slowly increase with beam energy from 95 nb at the lowest energy to about 250 nb at 5.4 MeV above threshold.     

Fast-neutron analysis at the Swedish Defence Research Agency

A fast-neutron analysis (FNA) system is being developed at the Swedish Defence Research Agency. The experimental set up, consisting of a SODERN Genie 16 (D-T) 14 MeV neutron generator, a HPGe-detector, a neutron monitor detector and related electronics, is described in some detail. Results from preliminary measurements on bulk samples containing mainly carbon and nitrogen are presented. Finally future objectives are discussed.     

Diffractive Alvarez lens

A diffractive Alvarez lens is demonstrated that consists of two separate phase plates, each having complementary 16-level surface-relief profiles that contain cubic phase delays. Translation of these two components in the plane of the phase plates is shown to produce a variable astigmatic focus. Both spherical and cylindrical phase profiles are demonstrated with good accuracy, and the discrete surface-relief features are shown to cause less than lambda/10 wave-front aberration in the transmitted wave front over a 40 mm x 80 mm region.     

Degree two Gaussian cubatures in the plane

In 1960 A. H. Stroud gave a construction from which all minimal degree two cubatures for an arbitrary region can be obtained. A special form of this construction is made here which results in cubatures for plane regions, in particular for convex quadrilaterals, which have positive weights and all nodes contained in the region. We refer to such rules as Gaussian cubatures.     

Pionic fusion study of the halo nucleus 6He, the reaction d+4He→6He+π + at CELSIUS

The halo nucleus ⁶He has been studied in a pionic fusion experiment at the CELSIUS storage ring facility in Uppsala. The ⁶He nuclei were produced in reactions with a deuteron beam incident on a ⁴He jet target 0.9–5.4 MeV above threshold in the center-of-mass frame. The ⁶He ions were detected in a ΔE-E solid-state detector telescope inserted into the CELSIUS ring. The aim of the experiment was to investigate, in particular, the high-momentum part of the halo wave function by measuring the total and differential cross sections of the reaction d+⁴He→⁶He+π ⁺.     

Improved separation of metallothionein isoforms by the presence of cyclodextrin in capillary zone electrophoresis

Capillary zone electrophoresis (CZE) with cyclodextrin (CD) in the polyacrylamide-coated capillary was used to study metallothionein (MT) forms in the horse kidney preparation produced commercially by Sigma. It is known that CDs form complexes with hydrophobic amino acids. The results show that the presence of CD improves the separability of the various MT forms, including the MT-IA and the MT-IB forms, metallothionein aggregates, as well as the so far unidentified a and b forms. This was true both below and above the isoelectric points (pIs), although the migration times were somewhat longer at increasing CD concentrations for runs at constant voltage than with constant current.     

Super-allowed beta decay of nuclei at the drip-line

We have investigated the continuous particle spectra following the beta decay of the neutron-rich nuclei that terminate the mass 6, 8, 9 and 11 isobaric chains. Strong beta transitions feeding the very top of the spectrum are found systematically. The favoured states are within a few MeV of the energy of the initial state. This phenomenon seems to be linked to the occurrence of a di-neutron structure or neutron halo in the drip-line nuclei.Dedicated to Prof. Dr. P. Kienle on the occasion of his 60th birthday     

Study of neutron rich neon isotopes

The half-lives andP _n -values of the neutron rich isotopes^26–29Ne have been determined. The results are compared to shell-model calculations and good agreement is found except for²⁹Ne, where the half-life exceeds the predictions by more than an order of magnitude. This unexpectedly long half-life can be explained as due to a fp intruder configuration.