Hospital-onset COVID-19 infection surveillance systems: a systematic review.

Hospital-onset COVID-19 infections (HOCIs) are associated with excess morbidity and mortality in patients and healthcare workers. The aim of this review was to explore and describe the current literature in HOCI surveillance. Medline, EMBASE, the Cochrane Database of Systematic Reviews, the Cochrane Register of Controlled Trials, and MedRxiv were searched up to 30 November 2020 using broad search criteria. Articles of HOCI surveillance systems were included. Data describing HOCI definitions, HOCI incidence, types of HOCI identification surveillance systems, and level of system implementation were extracted. A total of 292 citations were identified. Nine studies on HOCI surveillance were included. Six studies reported on the proportion of HOCI among hospitalized COVID-19 patients, which ranged from 0 to 15.2%. Six studies provided HOCI case definitions. Standardized national definitions provided by the UK and US governments were identified. Four studies included healthcare workers in the surveillance. One study articulated a multimodal strategy of infection prevention and control practices including HOCI surveillance. All identified HOCI surveillance systems were implemented at institutional level, with eight studies focusing on all hospital inpatients and one study focusing on patients in the emergency department. Multiple types of surveillance were identified. Four studies reported automated surveillance, of which one included real-time analysis, and one included genomic data. Overall, the study quality was limited by the observational nature with short follow-up periods. In conclusion, HOCI case definitions and surveillance methods were developed pragmatically. Whilst standardized case definitions and surveillance systems are ideal for integration with existing routine surveillance activities and adoption in different settings, we acknowledged the difficulties in establishing such standards in the short-term.

Direct and correlated responses to long-term selection for increased body weight and egg production in turkeys.

Lines of turkeys were selected long-term for increased egg production (E line; 34 generations) or increased 16-wk BW (F line; 28 generations). The E and F lines were started from randombred control populations (RBC1 and RBC2, respectively) that were also maintained to remove environmental variation among generations. Realized heritabilities (h2) +/- SE in the E line, based on regressions of response on cumulated actual selection differentials (selection differentials weighted for the number of offspring produced), for 180-d and 250-d egg production were 0.34 +/- 0.02 (17 generations) and 0.26 +/- 0.13 (8 generations), respectively. The realized h2 of 16-wk BW in the F line was 0.26 +/- 0.01. There was no consistent evidence of selection response reaching a plateau in either line. The genetic association of BW and egg production changed with selection in the E and F lines. The genetic correlation varied from near zero to strongly negative and fluctuated between these extremes in both lines even though they started from different base populations and selection criteria differed. Other correlated responses to selection for increased egg production were increased average clutch length (intensity of lay), and decreased broodiness (total days lost), egg weight, shell coloration, and rate of response to stimulatory lighting. Other correlated responses to selection for increased 16-wk BW in the F line included: increased egg weight (due to increased albumen), longer eating bouts, and decreased average clutch length, semen production, walking ability, and resistance to Pasteurella multocida and Newcastle disease virus. Selection within the E and F lines also changed the frequency of MHC haplotypes and the changes appeared to be in opposite directions in the two lines.

The crystallographic structure of the photooxidized product of hypocrellin A and the study of the photodynamic action mechanism.

In attempting to study the phototherapeutic action and the photosensitized oxygenation mechanism, we have determined the crystal structure of the main oxidized product of hypocrellin A (HA). It was crystallized in monoclinic system with space group P2(1). The cell data are: a = 10.030(3), b = 8.877(3), c = 15.764(5)A, beta = 104.50(2) degrees, Z = 2. The crystal structure has been determined by direct method and refined to a final R of 0.055 based on the 1408 observed reflections with I greater than 2.5 sigma (I). The photooxidized product is composed of a heptacyclic aliphatic hydrocarbon connecting with two alpha-naphthoquinone derivatives as its skeletal molecule. No peroxidic linkage has been found. On the basis of the crystal structure determined, we have deduced part of the process of formation of the oxide, i. e. firstly, the peroxide was formed by photocycloaddition of oxygen molecule to Hypocrellin A, then thermodissociation took place to form a stable oxide.