A repeating fast radio burst source in a globular cluster.

Fast radio bursts (FRBs) are flashes of unknown physical origin1. The majority of FRBs have been seen only once, although some are known to generate multiple flashes2,3. Many models invoke magnetically powered neutron stars (magnetars) as the source of the emission4,5. Recently, the discovery6 of another repeater (FRB 20200120E) was announced, in the direction of the nearby galaxy M81, with four potential counterparts at other wavelengths6. Here we report observations that localized the FRB to a globular cluster associated with M81, where it is 2 parsecs away from the optical centre of the cluster. Globular clusters host old stellar populations, challenging FRB models that invoke young magnetars formed in a core-collapse supernova. We propose instead that FRB 20200120E originates from a highly magnetized neutron star formed either through the accretion-induced collapse of a white dwarf, or the merger of compact stars in a binary system7. Compact binaries are efficiently formed inside globular clusters, so a model invoking them could also be responsible for the observed bursts.

Facile gold nanorod purification by fractionated precipitation.

An efficient and facile size- and shape-selective separation of gold nanorod (GNR) solutions is developed using a fractionated precipitation strategy. This convenient method has the benefit of eliminating nanoparticulate side products that can substantially deteriorate the quality of self-assembled nanostructures. The fabrication of advanced plasmonic metamaterials crucially depends on the capacity to supply feedstocks of high-purity building blocks.

Highly efficient photocathodes for dye-sensitized tandem solar cells.

Thin-film dye-sensitized solar cells (DSCs) based on mesoporous semiconductor electrodes are low-cost alternatives to conventional silicon devices. High-efficiency DSCs typically operate as photoanodes (n-DSCs), where photocurrents result from dye-sensitized electron injection into n-type semiconductors. Dye-sensitized photocathodes (p-DSCs) operate in an inverse mode, where dye-excitation is followed by rapid electron transfer from a p-type semiconductor to the dye (dye-sensitized hole injection). Such p-DSCs and n-DSCs can be combined to construct tandem solar cells (pn-DSCs) with a theoretical efficiency limitation well beyond that of single-junction DSCs (ref. 4). Nevertheless, the efficiencies of such tandem pn-DSCs have so far been hampered by the poor performance of the available p-DSCs (refs 3, 5-15). Here we show for the first time that p-DSCs can convert absorbed photons to electrons with yields of up to 96%, resulting in a sevenfold increase in energy conversion efficiency compared with previously reported photocathodes. The donor-acceptor dyes, studied as photocathodic sensitizers, comprise a variable-length oligothiophene bridge, which provides control over the spatial separation of the photogenerated charge carriers. As a result, charge recombination is decelerated by several orders of magnitude and tandem pn-DSCs can be constructed that exceed the efficiency of their individual components.

Influence of different tumour types on natural cytotoxicity (NK cell activity) and mitogen-induced lymphocyte proliferation in isolated blood lymphocytes from 110 dogs with tumours.

The cell-mediated immune response of blood lymphocytes from 110 untreated dogs with different tumours was evaluated. The influence of different tumour types on the cellular immune system was examined by assessing the percentage of isolated large granular lymphocytes (LGL), in vitro natural cytotoxicity and mitogen-induced lymphocyte proliferation. Although the overall natural cytotoxicity of dogs with different tumours was decreased, the overall difference from control values was not statistically significant. However, mitogen-induced lymphocyte proliferation was significantly depressed in dogs with tumours in comparison with the controls. Dogs with mammary carcinomas showed significantly lower natural cytotoxicity than controls and dogs with myeloid neoplasms showed significantly lower mitogen-induced lymphocyte proliferation. Abnormalities exist not only in natural cytotoxicity but also in mitogen-induced lymphocyte proliferation. For the dog, this is the first study to assess the influence of different tumours using a combined evaluation of natural cytotoxicity and mitogen-induced lymphocyte proliferation in such a large number of animals.

Apoptotic cell debris and phosphatidylserine-containing lipid vesicles induce apolipoprotein J (clusterin) gene expression in vital fibroblasts.

The molecular events in cells undergoing programmed cell death (apoptosis) are well studied; however, the response of the surviving neighbor cells to local cell death is largely uncharacterized. Apolipoprotein J (clusterin) is an 80-kDa glycoprotein that has been implied in cytoprotection of the vital cells, presumably by assisting in the clearance of apoptotic vesicles and membrane remnants. Its mRNA is specifically up-regulated in the vital cells of apoptotic tissues. The molecular mechanisms, however, leading to this response are not known. We here show that exposure of vital fibroblasts to apoptotic vesicles, disrupted vital cells, and trypsin-treated membrane remnants induces apoJ mRNA. Moreover, lipid vesicles consisting of phosphatidylserine (PtSer) and dimyristoylphosphatidylcholine (PC), but not liposomes with PC alone nor with dimyristoylphosphatidylethanolamine or phosphatidic acid, did elevate apoJ mRNA level. These results suggest that, apart from mediating the endocytic uptake of the apoptotic vesicles, PtSer also serves as a trigger to stimulate the expression of genes that might be involved in the cellular clearance process.

Prion protein contains a second endoplasmic reticulum targeting signal sequence located at its C terminus.

Prion protein (PrP) is synthesized at the membrane of the endoplasmic reticulum (ER) in three different topological forms as follows: a fully translocated one ((sec)PrP) and two with opposite orientations in the membrane ((Ntm)PrP and (Ctm)PrP). We asked whether other signal sequences exist in the PrP, other than the N-terminal signal sequence, that contribute to its topological diversity. In vitro translocation assays showed that PrP lacking its N-terminal signal sequence could still translocate into ER microsomes, although at reduced efficiency. Deletion of each of the two hydrophobic regions in PrP revealed that the C-terminally located hydrophobic region (TM2) can function as second signal sequence in PrP. Translocation mediated by the TM2 alone can occur post-translationally and yields mainly (Ctm)PrP, which is implicated in some forms of neurodegeneration in prion diseases. We conclude that, in vitro, PrP can insert into ER membranes co- and post-translationally and can use two different signal sequences. We propose that the unusually complex topology of PrP results from the differential utilization of two signal sequences in PrP.

Formation of positively charged microcapsules based on chitosan-lecithin interactions.

The formation of microcapsules which contain rosemary oil, is herewith described. The process is based on two steps: (a) formation of oil-in-water emulsions, by using lecithin as emulsifier, thus imparting negative charges on the oil droplets; (b) addition of a cationic biopolymer, chitosan, in conditions that favor the formation of an insoluble chitosan-lecithin complex. Zeta potential measurements revealed that addition of very low concentrations of chitosan to lecithin stabilized emulsions, led to reversal of charge. At a suitable pH range the chitosan precipitated around the oil droplets, forming positively charged microcapsules. The chitosan-lecithin insoluble complex is composed of a 1:1 molar ratio of the chitosan monomeric unit and lecithin, as evaluated by elementary analysis and turbidity measurements.

[An unusual course of thoracic actinomycosis]. / Ungewöhnlicher Verlauf einer thorakalen Aktinomykose.

A 56-year-old farmer who had been suffering from exogenous allergic alveolitis developed, after a long prodromal period of illness, a granulocyte-rich pericardial effusion and bilateral pleural effusions in which Actinomyces aggregates were identified. Despite intensive treatment with clindamycin, erythromycin and tetracycline (he was allergic to penicillin) he died in septic shock.

A case of accidental cyclosporin overdose with pharmacokinetic analysis.

In a case of oral overdose of cyclosporin we measured plasma concentrations by radioimmunoassay and high pressure liquid chromatography. We observed unchanged pharmacokinetic parameters after the overdose indicating normal renal and hepatic function. Laboratory findings showed no renal or hepatic damage. As toxic symptoms, only emesis and a short, mild drowsiness were noted.

Philadelphia-positive chronic myelogenous leukemia with breakpoint 5' of the breakpoint cluster region but within the bcr gene.

We report on the first Philadelphia chromosome (Ph) positive chronic myelogenous leukemia (CML) characterized by a rearrangement within the 5' part of the bcr gene on chromosome 22, but outside the restricted breakpoint cluster region. In situ hybridization studies revealed a translocation of the c-abl oncogene to the Ph chromosome and Northern blot analysis identified a chimeric 8 kb bcr/abl RNA transcript in leukemic cells. These data suggest that 1. less bcr coding sequences than previously assumed may be essential for the putative transforming activity of the rearranged bcr/abl gene and 2. the bcr probes currently used for diagnostic purposes could miss Ph-positive CML cases.

[Ulcerative colitis caused by oral gold therapy in rheumatoid arthritis]. / Ulzerierende Kolitis unter oraler Goldtherapie bei rheumatoider Arthritis.

We report on a 39-year-old male patient suffering from seropositive rheumatoid arthritis who developed severe colitis during oral gold (Auranofin) therapy. So far, two further cases of colitis during oral, and 28 cases of enterocolitis during parenteral chrysotherapy have been described. The pathomechanism has not been identified. Symptomatic therapy was applied, under which our patient recovered from intestinal discomfort in a few weeks. In differential diagnosis gold induced colitis has to be distinguished both from loose stools occurring during oral gold therapy, most probably caused by an inhibition of NA+K+ ATPase, and from colitis induced by concomitant application of nonsteroidal anti-inflammatory drugs.

[Some considerations on the goals of rehabilitation (author's transl)]. / Zur Zielvorstellung der Rehabilitation.

Has not the term "rehabilitation" been very frequently used lately to describe exclusively vocational rehabilitation? If, however, "rehabilitation" does not cover all aspects of rehabilitation including the efforts made to provide the severely handicapped with the opportunity of developing their potential to the fullest then the severely handicapped are automatically considered segregated. What we do for them can only be described in a negative way. We are unable to integrate them vocationally but we do not want to leave them their fate, either. Without a positive exression for the efforts made for these fellow-citizens alone from the way we think and talk this part of rehabilitation implies inhuman tendencies.

[Are we pushing the disabled intellectually into a ghetto? (AUTHOR'S TRANSL)]. / Drängen wir die Behinderten geistig ins Getto? Uberlegungen aus theologischer Sicht zur Notwendigkeit einer weltanschaulichen Rehabilitation

Disabled people not only encounter barriers in their physical environment (in the form of steps which social rehabilitation is making efforts to level, remove or overcome through ramps) but also in the intellectual and emotional fields (in the life and thinking habits of our society, in expressions, song texts, etc.) i.e. basic expressions which seem to be applicable to the lives of the non-disabled but which prevent the disabled's access to life in the community. The examples given are: "What you are depends on what you have", "the world is beautiful", "everything will turn out all right". These expressions are, at least, as detrimental to full integration as the steps at the entrance to the post-office. The elimination of these sayings would not be beneficial to the disabled alone, but to all people: our life would become more honest and less strained. Phrases of the Biblical Message serve as the example for a thinking model which could give the impetus to a common learning process of tension release. Efforts to lessen the restraint (that is to correct the cited expressions) are called "weltanschauliche Rehabilitation", but whether this should rather be understood as a part of social rehabilitation or its parallel is a question which still remains unanswered.