Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Surgical competence

Recent high-profile cases have heightened the need for a formal structure to monitor achievement and maintenance of surgical competence. Logbooks, morbidity and mortality meetings, videos and direct observation of operations using a checklist, motion analysis devices, and virtual reality simulators are effective tools for teaching and evaluating surgical skills. As the operating theater is also a place for training, there must be protocols and guidelines, including mandatory standards for supervision, to ensure that patient care is not compromised. Patients appreciate frank communication and honesty from surgeons regarding their expertise and level of competence. To ensure that surgical competence is maintained and keeps pace with technologic advances, professional registration bodies have been promoting programs for recertification. They evaluate performance in practice, professional standing, and commitment to ongoing education.link_to_subscribed_fulltex

Two murine monclonal antibodies against serogroup E Salmonellae

A monoclonal antibody (MAb), MO15, was raised against the lipopolysaccharide antigen of an epsilon15-lysogenized serogroup E(1) Salmonella strain. The O factor 15-specific MAb MO15, together with another serogroup E-specific MAb, can differentiate among phage lysogenization variants in serogroup E salmonellae. Their epitope specificities in relation to conventional O-antigenic structures are discussed.published_or_final_versio

Acute sporadic hepatitis E virus infection in southern China

BACKGROUND/AIMS: The hepatitis E virus is responsible for epidemic and sporadic hepatitis in northwestern China, but its role as a cause of acute sporadic hepatitis in southern China has not been reported. METHODS: We applied the most practical current methods for diagnosis of hepatitis E virus infection, IgM and IgG anti-HEV detection by enzyme linked immunosorbent assay, to investigate the prevalence of hepatitis E virus infection among acute sporadic hepatitis. RESULTS: Anti-HEV IgM was found in 1 of 26 (3.8%), 4 of 20 (20.0%), 4 of 19 (21.1%), and 51 of 142 (35.9%), with acute hepatitis A, B, C and non-ABC, respectively. Anti-HEV IgM was not detectable in healthy subjects, while IgG anti-HEV was found in 14 of 77 healthy subjects (18.2%) and was long-lasting. Ninety-one cases without any evidence of hepatitis A, B or C infections and anti-HEV IgM were tentatively classified as non-A, B, C, D, E (non-ABCDE) hepatitis. By comparison with non-ABCDE, cases with hepatitis E were more frequently icteric and exhibited higher alanine aminotransferase levels (92.2% vs. 45.1%, 770 iu/l vs 377 iu/l, respectively, p < 0.005). Chronic cases were not observed in hepatitis E virus infections. However, 14 of 91 (15.4%) cases with non-ABCDE developed to chronicity (p < 0.005). CONCLUSIONS: Hepatitis E virus infection is sporadic as well as endemic in southern China. Only IgM anti-HEV but not IgG anti-HEV can be used as an appropriate marker of acute hepatitis E virus infection. Superinfection of hepatitis E virus with other types of hepatitis viruses is frequent in this area. While the disease was associated with more severe clinical manifestations, patients usually recovered completely

Occurrence of hepatitis E virus IgM, low avidity IgG serum antibodies, and viremia in sporadic cases of non-A, -B, and -C acute hepatitis

Serum samples were taken from 57 patients with sporadic non-A, -B, and -C (Non A, B, C) acute hepatitis at different times after onset of the disease and tested for the presence of the hepatitis E virus (HEV) RNA, IgM, and low avidity IgG antibodies. The viral antibodies were detected using two ELISA. One assay (GL) was produced using a mixture of recombinant peptides specified by ORF2 and ORF3 of the viral genome. The other was produced with an ORF2 specified peptide, pE2. The latter occurs naturally as homodimer, it is recognized strongly in its dimeric form by human sera and, in the primate model, it confers protection against experimental HEV infection. Nineteen samples were positive for one or more of these acute markers of HEV infection, 14 of which were acute sera with elevated ALT levels and 5 were convalescent sera with normal ALT level. The results showed that icteric phase of sporadic hepatitis lasts for about 17 days and it coincides with a period when viremia is subsiding as HEV antibodies are developing. Viremia was intermittent and all but one of the 5 instances were confined to the icteric phase with elevated ALT levels. On two of these occasions, viremia preceded detection of HEV antibody, on another 2 occasions it was concurrent with the detection of pE2 specific IgM and/or low avidity IgG and only in one case of protracted viremia was the viral genome detected concurrently with avid pE2 IgG antibody. Ten (71%) of the 14 acute sera were reactive for pE2 IgM, eight (57%)were reactive for low avidity pE2 IgG, and six (43%) for the GL IgM. The sensitivity for the diagnosis of acute hepatitis E may be increased to 87% by combining pE2 IgM and viremia. GL IgM was detected later, but persisted for a longer period of time than the pE2 antibodies, and it was the only acute antibody detected in the convalescent sera. © 2002 Wiley-Liss, Inc.link_to_subscribed_fulltex

Effective management of breathlessness in Advanced Cancer Patient with a Program-based, Multi-disciplinary Approach: SOB Program in Hong Kong

Conference Theme: Building Bridge

Synthesis, photoluminescent and electroluminescent behaviour of four- coordinate tetrahedral gold(I) complexes. X-ray crystal structure of [Au(dppn)2]Cl

Two tetrahedral four-coordinate Au(I) complexes, [Au(4-R-dppn)2]PF6 (R = H or Me), have been synthesized and the crystal structure of [Au(dppn)2]Cl has been determined by X-ray crystallography; the complexes have been found to exhibit both photoluminescent and electroluminescent behaviour.link_to_subscribed_fulltex

Emerging pathogens: The Hong Kong experience

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