Photonic Source of Heralded Greenberger-Horne-Zeilinger States.

Generating large multiphoton entangled states is of main interest due to enabling universal photonic quantum computing and all-optical quantum repeater nodes. These applications exploit measurement-based quantum computation using cluster states. Remarkably, it was shown that photonic cluster states of arbitrary size can be generated by using feasible heralded linear optics fusion gates that act on heralded three-photon Greenberger-Horne-Zeilinger (GHZ) states as the initial resource state. Thus, the capability of generating heralded GHZ states is of great importance for scaling up photonic quantum computing. Here, we experimentally demonstrate this required building block by reporting a polarisation-encoded heralded GHZ state of three photons, for which we build a high-rate six-photon source (547±2 Hz) from a solid-state quantum emitter and a stable polarization-based interferometer. The detection of three ancillary photons heralds the generation of three-photon GHZ states among the remaining particles with fidelities up to F=0.7278±0.0106. Our results initiate a path for scalable entangling operations using heralded linear-optics implementations.

Splash of a waterdrop at terminal velocity.

High-speed movies of splash formation caused by waterdrop impact at terminal velocity in thin water layers show that splash size increases with drop size. For increasing water depth, splash size increases to a maximum at a depth of one-third drop diameter; splash size then decreases to a constant size for depths greater than three drop diameters.

Cloning and sequence of the groESL heat-shock operon of Pasteurella multocida.

By using degenerate oligodeoxyribonucleotide primers for conserved regions of groEL, a 0.6-kb fragment of Pasteurella multocida genomic DNA was amplified using PCR. The amplified fragment was then used as a probe to isolate a genomic fragment containing the entire GroESL operon. The isolated genomic fragment was found to contain two open reading frames, the sequences of which were highly homologous to the prokaryotic groES and groEL families of genes.

Selective inhibitors of glial GABA uptake: synthesis, absolute stereochemistry, and pharmacology of the enantiomers of 3-hydroxy-4-amino-4,5,6,7-tetrahydro-1,2-benzisoxazole (exo-THPO) and analogues.

3-Methoxy-4,5,6,7-tetrahydro-1,2-benzisoxazol-4-one (20a), or the corresponding 3-ethoxy analogue (20b), and 3-chloro-4,5,6, 7-tetrahydro-1,2-benzisothiazol-4-one (51) were synthesized by regioselective chromic acid oxidation of the respective bicyclic tetrahydrobenzenes 19a,b and 50, and they were used as key intermediates for the syntheses of the target zwitterionic 3-isoxazolols 8-15 and 3-isothiazolols 16 and 17, respectively. These reaction sequences involved different reductive processes. Whereas (RS)-4-amino-3-hydroxy-4,5,6,7-tetrahydro-1,2-benzisoxazole (8, exo-THPO) was synthesized via aluminum amalgam reduction of oxime 22a or 22b, compounds 9, 11-13, and 15-17 were obtained via reductive aminations. Compound 10 was synthesized via N-ethylation of the N-Boc-protected primary amine 25. The enantiomers of 8 were obtained in high enantiomeric purities (ee >/= 99.1%) via the diastereomeric amides 32 and 33, synthesized from the primary amine 23b and (R)-alpha-methoxyphenylacetyl chloride and subsequent separation by preparative HPLC. The enantiomers of 9 were prepared analogously from the secondary amine 27. On the basis of X-ray crystallographic analyses, the configuration of oxime 22a was shown to be E and the absolute configurations of (-)-8 x HCl and (+)-9 x HBr were established to be R. The effects of the target compounds on GABA uptake mechanisms in vitro were measured using a rat brain synaptosomal preparation and primary cultures of mouse cortical neurons and glia cells (astrocytes). Whereas the classical GABA uptake inhibitor, (R)-nipecotic acid (2), nonselectively inhibits neuronal (IC(50) = 12 microM) and glial (IC(50) = 16 microM) GABA uptake and 4,5,6,7-tetrahydroisoxazolo¿4,5-cpyridin-3-ol (1, THPO) shows some selectivity for glial (IC(50) = 268 microM) versus neuronal (IC(50) = 530 microM) GABA uptake, exo-THPO (8) was shown to be more potent as an inhibitor of glial (IC(50) = 200 microM) rather than neuronal (IC(50) = 900 microM) GABA uptake. This selectivity was more pronounced for 9, which showed IC(50) values of 40 and 500 microM as an inhibitor of glial and neuronal GABA uptake, respectively. These effects of 8 and 9 proved to be enantioselective, (R)-(-)-8 and (R)-(+)-9 being the active inhibitors of both uptake systems. The selectivity of 9 as a glial GABA uptake inhibitor was largely lost by replacing the N-methyl group of 9 by an ethyl group, compound 10 being an almost equipotent inhibitor of glial (IC(50) = 280 microM) and neuronal (IC(50) = 400 microM) GABA uptake. The remaining target compounds, 11-17, were very weak or inactive as inhibitors of both uptake systems. Compounds 9-13 and 15 were shown to be essentially inactive against isoniazide-induced convulsions in mice after subcutaneous administration. The isomeric pivaloyloxymethyl derivatives of 9, compounds 43 and 44, were synthesized and tested as potential prodrugs in the isoniazide animal model. Both 43 (ED(50) = 150 micromol/kg) and 44 (ED(50) = 220 micromol/kg) showed anticonvulsant effects, and this effect of 43 was shown to reside in the (R)-(+)-enantiomer, 45 (ED(50) = 44 micromol/kg). Compound 9 also showed anticonvulsant activity when administered intracerebroventricularly (ED(50) = 59 nmol).

The effect of cutaneous and deep pain on the electroencephalogram during sleep--an experimental study.

The interaction between sleep and pain has been insufficiently studied, and no experiments have investigated whether pathologic sleep patterns as seen in pain patients can be replicated experimentally by well-defined pain stimuli. An experimental model would therefore be valuable for further studies on the interaction between pain and sleep. In this study, three well-defined experimental stimuli (muscle, joint, and cutaneous pain) were applied during sleep, and the electroencephalogram (EEG) pattern was quantified. The pain stimuli were applied during slow-wave sleep in 10 healthy subjects. Using nine surface recordings, the EEG was sampled before and during pain stimuli. Frequency analysis was performed, resulting in 10 EEG features describing the responses to pain. During the muscle-pain stimulus an arousal effect was observed and a decrease in delta (0.5-3.5 Hz) and sigma (12-14 Hz) as well as increases in alpha 1 (8-10 Hz) and beta (14.5-25 Hz) activities were seen. During joint pain, however, more universal EEG changes were seen with a decrease in the lowest frequency bands [delta, theta (3.5-8 Hz) and alpha 1] and an increase in the higher frequencies [alpha 2 (10-12 Hz), sigma and beta bands]. No background EEG changes were observed during the cutaneous stimulus. There were several differences in the responses from the nine EEG channels, but no derivation seemed especially sensitive to detect the evoked changes. The study highlights the complexity of pain on the sleep EEG. The experimental model has shown that pain from different body structures, as well as signals from various EEG derivations, may give different responses in sleep microstructure.

Haloperidol overdose during pregnancy.

BACKGROUND: Suicide attempts during pregnancy are rare. Over-the-counter and psychotropic medications are most commonly used. Although intentional overdose of haloperidol has been reported in nonpregnant adults, it has not, to our knowledge, been reported previously during pregnancy. In this case of suicide attempt by haloperidol overdose, maternal and fetal responses were studied extensively. CASE: Intentional ingestion of 300 mg haloperidol by a pregnant woman at 34 weeks' gestation caused maternal unresponsiveness, an extrapyramidal reaction, temporary fetal akinesia, and a nonreactive nonstress test. The mother recovered in 48 hours. The fetus did not reach a biophysical profile score of ten until 5 days after presentation. CONCLUSION: Haloperidol overdose during pregnancy causes a maternal extrapyramidal reaction, temporary fetal akinesia, and prolonged fetal neuromuscular depression.

Serum resistance is correlated with encapsulation of avian strains of Pasteurella multocida.

Encapsulated avian strains of Pasteurella multocida possessing an A-type capsule were shown to be resistant to the bactericidal action of turkey serum, whereas unencapsulated variants as well as other unencapsulated strains were not. Removal of the capsule from serum-resistant strain P1059-1 resulted in this strain becoming susceptible to the bactericidal effects of turkey serum. Since complement was consumed when encapsulated or unencapsulated strain P1059-1 was incubated in turkey serum, we conclude that the capsule acts to shield the outer membrane rather than prohibiting the generation of an effective membrane attack complex.

Pasteurella multocida enters polarized epithelial cells by interacting with host F-actin.

We investigated the interaction of an avian strain of Pasteurella multocida with the cytoskeleton of MDCK cells, which formed a polarized epithelium when grown on type I collagen coated filters. Bacteria were incubated with MDCK cells for 30 min. 2, 4 and 6 hours and their location and association with the cell cytoskeleton determined by double-label immunofluorescence confocal microscopy. Cells were stained with a polyclonal antiserum to the outer-membrane proteins of P. multocida and with rhodamine phalloidin which specifically binds filamentous (F) actin. Confocal microscopy revealed that bacteria entered the cells by 30 min, and that by 6 hours there was a marked alteration in the actin cytoskeleton in which long filaments were reorganized to discrete foci of short actin filaments, within which were one or more bacteria. Electron microscopy demonstrated that by 2 hours, each bacterium was associated with many short 5-6 nm filaments. Treatment of MDCK cells with cytochalasin D for either 30 minutes or 24 hours prior to infection disrupted the actin cytoskeleton and inhibited entry of P. multocida.

Obesity and GnRH action. Report of a case with contribution by peripherally derived estrogens.

BACKGROUND: Gonadotropin-releasing hormone agonists (GnRH-a) are effective in reducing the pituitary release of gonadotropins, which, in turn, decrease ovarian steroidogenesis. The resulting menopausal state decreases the volume and vascular supply to uterine leiomyomas. Peripheral adipose tissue also contributes significantly to the circulatory estrogen pool, which is formed independent of pituitary function. As such, obesity may interfere with depot leuprolide acetate effects, allowing normal estrogen levels despite gonadotropin suppression. CASE: A premenopausal, morbidly obese woman was referred for treatment of menorrhagia and uterine leiomyomas. Despite administration of depot leuprolide, a GnRH-a, she continued to bleed heavily. Serum estradiol levels remained in the normal range, with suppression of follicle-stimulating hormone (FSH) levels. The desired hypoestrogenic effect from GnRH-a administration was thought to be negated by estradiol levels arising from peripherally derived conversion of adrenal androgens in adipose tissue. A GnRH stimulation test was performed to evaluate the responsiveness of the pituitary to the above therapy. While FSH was suppressed and unresponsive to stimulation, estradiol remained unchanged. CONCLUSION: Peripheral production of estrogen appears to be unaffected by leuprolide administration. Consideration should be given to the patient's body habitus when administering a GnRH suppressant. Morbidly obese patients possess an unlimited reservoir for peripheral estrogen synthesis.

Use of random fragments of chromosomal DNA to highlight restriction site heterogeneity for fingerprinting isolates of Salmonella typhimurium from hospitalized animals.

Random fragments of DNA were obtained from a cosmid library of Salmonella agona genomic DNA. From this library, 2 fragments were chosen and pooled to probe isolates of S typhimurium obtained during an episode of salmonellosis in a veterinary medical teaching hospital. Chromosomal DNA from the Salmonella isolates was digested with restriction endonucleases, and was probed with the random fragments of chromosomal DNA. This procedure resulted in a fingerprint pattern for each isolate. We found that the method permitted discrimination between isolates involved in the disease episode and S typhimurium obtained prior to the episode. We conclude that random fragments of chromosomal DNA are useful for fingerprinting isolates of S typhimurium. Analysis of plasmid DNA obtained from the isolates was not as useful. Some isolates found to be identical by restriction site analysis, had plasmids of different molecular weight. These results indicate that plasmid analysis may not be as useful a fingerprinting tool as previously reported.

Plasma- and iron-regulated expression of high molecular weight outer membrane proteins by Pasteurella multocida.

A strain of Pasteurella multocida of avian origin expressed high molecular weight outer membrane proteins when grown in turkey plasma or in brain-heart infusion broth containing the iron chelator dipyridyl. The proteins were not detected when this strain was grown in brain-heart infusion broth or in brain-heart infusion broth containing dipyridyl and excess iron.

[Leptospirosis. A disease with non-specific initial symptoms]. / Leptospirosis. En sygdom med uspecifikke debutsymptomer.

A case of leptospirosis in a young fish-farm worker is described. Early penicillin therapy was initiated solely on the clinical suspicion of the disease. The importance of recognition of the disease is emphasized together with early institution of penicillin therapy and effective eradication of vermin.

[Neuropathy in adult metachromatic leukodystrophy]. / Neuropati ved adult metakromatisk leukodystrofi.

Metachromatic leukodystrophy is a rare autosomal recessive disorder with deficient arylsulphatase A activity. Different forms occur according to the age at onset of symptoms. Adult forms generally present with presenile dementia and/or psychiatric symptoms. We report a case of a 45-year-old woman, without a family history of neuropsychiatric disorders, presenting with complaints of numbness and weakness of the lower limbs. No intellectual or behavioral disturbances were clinically detectable. Electrophysiological investigation was compatible with severe demyelinating neuropathy in upper and lower limbs. MRI of the brain showed multiple white matter lesions. Adult metachromatic leukodystrophy was diagnosed on the basis of low leucocyte arylsulfatase-A-activity and accumulation of metachromatic material in the sural nerve. Pseudo-deficiency was excluded by DNA analysis. This case indicates that adult metachromatic leukodystrophy should be considered in patients with symptoms and signs resembling multiple sclerosis with peripheral neuropathy and in patients with neuropathy of unknown etiology.

[Knowledge of AIDS and of transmission risks of HIV infection in a group of homosexual people. A questionnaire study]. / En gruppe homoseksuelles viden om AIDS og smitterisikoen ved HIV-infektion. En spørgeskemaundersøgelse.

A questionnaire investigation among 430 homosexual persons all of whom were members of an organization for homosexuals was completed by 144 (33%). These replies showed that they knew about HIV infection, risk behaviour and "safe sex". Their knowledge about the signs of HIV infection and AIDS was, however, more limited. The replies were compared with an age-matched group of the male population. The results of the investigation provide reasons to suppose that the information campaigns have been of value but information to prevent spread of infection is still necessary. In addition, further information is necessary about the subjective signs of HIV-infection so that persons in whom these signs develop may be offered the best possible treatment as early as possible.

[A group of homosexuals change their sex habits after information about AIDS. A questionnaire survey]. / En gruppe homoseksuelles aendringer i seksualvaner efter information om AIDS. En spørgeskemaundersøgelse.

A questionnaire investigation to which 144 homosexual persons replied anonomously revealed alterations in the sexual habits after information about AIDS. Significant reduction in the annual number of partners and significantly fewer employ the more dangerous sexual practices which now occur particularly in more permanent partnerships are among the alterations started. An unchanged number still employ active anal and orogenital coitus. Employment of condoms has increased significantly, particularly in anal coitus and "casual" partners (from 3% to 82%). The majority accept the use of condoms and state that they employ more "safe sex" than prior to information about AIDS. 12% stated that they had sex with both sexes and the possibility of spread of infection from homosexual to heterosexual groups is present. The intensive informative work from the homosexuals own organisation and from public health authorities appear to have had some effect but further information and influencing are necessary if the spread of HIV infection is to be stopped.