Temperature dependence on bandgap of semiconductor photocatalysts.

Light irradiation onto a semiconductor generates heat; however, its electronic structure under high temperature has not yet been well investigated. In this study, we have carefully examined the temperature dependence on the bandgap of simple metal oxides, which are well-known photocatalysts, i.e., TiO2, CeO2, Nb2O5, SnO2 Ta2O5, WO3, ZnO, and ZrO2, using operando UV-visible spectroscopy under controlled temperature (from room temperature to 500 °C). Consequently, a linear decrease in bandgap was seen as a function of temperature with a different slope for each semiconductor. We found that the slope was dependent on the bonding distance between metal and oxygen. This finding is essential to develop a photocatalyst used under the condition involving photo-thermal effect.

A survey of the implementation status of selected infection control strategies in neonatal intensive care units in Japan.

BACKGROUND: Infection control strategies are implemented in all neonatal intensive care units (NICUs); however, the details of the strategies seem to differ among institutions. The purpose of this survey was to investigate the current implementation status of infection control strategies in NICUs in Japan and to identify and recommend appropriate strategies for the prevention of outbreaks in neonatal units. METHODS: This survey documented the current implementation status and methods of selected infection prevention and control measures (active surveillance cultures and standard precaution) in 453 Japanese NICUs/neonatal units registered with the Japan Society of Perinatal and Neonatal Medicine, using questionnaires, in May 2018. FINDINGS: The response rate was 48.1% (level I institutions, 25.5%; level II, 55.9%; level III, 64.2%). Surveillance cultures were performed every week and targeted all bacteria in most units. The proportion of level III institutions that experienced outbreaks over the previous five years was significantly higher than that of level II institutions (55% vs 27%, P=0.0003). However, wearing a mask was less frequently recommended in level III institutions (55.7%) than in level II institutions (67.9%). Meticillin-resistant Staphylococcus aureus (MRSA) was the most frequently reported bacterial pathogen responsible for NICU outbreaks. CONCLUSION: Infection prevention and control practices regarding active pathogen surveillance cultures and the use of barrier precautions varied widely in Japanese neonatal units. National guidelines and evidence-based recommendations are needed to rationalize and standardize current infection prevention and control practices in neonatal units in Japan.

The efficacy of the direct clinical intervention for infectious diseases by a pediatric infectious disease specialist in the pediatric ward of a tertiary medical facility without a pediatric antimicrobial stewardship program.

Antimicrobial stewardship programs (ASPs) have been introduced in most hospital complexes; however, they are not always useful for pediatric patients. The aim of this study is to investigate the efficacy of direct clinical intervention for infectious diseases by a pediatric infectious disease specialist in a tertiary medical facility without pediatric ASP. This retrospective study included 1,821 patients who were hospitalized in the pediatric ward of a large metropolitan hospital from 2010 to 2015. The clinical course, the use of intravenous antimicrobial agents and the results of a microbiological analysis were compared between the period after the beginning of direct intervention by the specialist (post-intervention period) and the previous period (pre-intervention period). In the post-intervention period, the proportion of the patients who received intravenous antimicrobial agents, the number of antimicrobial agents used for each episode, and the proportion of episodes in which an antimicrobial agent was re-administrated were significantly lower (P = 0.006, P = 0.004, P = 0.036, respectively), and the duration of antimicrobial treatment was significantly shorter (P < 0.001). In addition, narrower spectrum antimicrobial agents were used, and the incidence of meropenem-sensitive Pseudomonas aeruginosa significantly increased (P = 0.037) in the post-intervention period. There was no change of mortality between the two periods. Direct clinical intervention by a pediatric infectious diseases specialist is useful for the treatment of infectious diseases in the pediatric ward of a tertiary medical facility without a pediatric ASP. The creation of a pediatric ASP is recommended in hospital complexes.

Respiratory syncytial virus infection in children with severe motor and intellectual disabilities.

Children with severe motor intellectual disabilities (SMID) are at high risk of death from acute viral lower respiratory tract infections (LRTI). Although respiratory syncytial virus (RSV) is the most common cause of viral LRTI in children, there have been a few reports on the relationship between SMID and the severity of RSV-LRTI. The aim of the present study is to assess the influence of RSV-LRTI in children with SMID. A case-control study composed of children with SMID (n = 18) and previously healthy children (n = 43) less than 16 years old hospitalized for RSV-LRTI was performed during five consecutive RSV seasons. The clinical presentation and the laboratory data in the SMID group were compared with those in the non-SMID group. In the bivariate analysis, the median age of the SMID group was higher than that of the non-SMID group (p = 0.002). Children with SMID had an increased risk for ventilation support (p = 0.057). The count of neutrophils in the SMID group was significantly increased (p = 0.012), whereas the proportion of bacterial co-infection was lower than that in the non-SMID group (p = 0.005). Multivariate logistic analysis showed that SMID was associated with longer oxygen usage [>7 days: odds ratio (OR) 5.309, p = 0.033]. The present study revealed that children with SMID were prone to developing hypoxia by RSV-LRTI. The strategies for the treatment and prevention of RSV infection need to be improved in SMID children.

Identification of bacterial pathogens in pediatric community-acquired lower respiratory tract infection using a simplified procedure of sputum sampling and examination: comparison between hospitalized children with and without underlying diseases.

The aim of this study is to confirm the usefulness of sputum sampling from the hypopharynx through the nose to identify causative bacteria of pediatric community-acquired lower respiratory tract infection (CA-LRTI) and compare its features between the patients with and without underlying diseases. A retrospective study was performed on 244 pediatric patients hospitalized for CA-LRTI of suspected bacterial etiology. Sputum sample was obtained from these patients by aspirating airway secretion through the nose or the tracheostomy orifice, or coughing up by themselves. Sputum samples were assessed as suitable in 119 (74.4%) of 160 patients with CA-LRTI of suspected pure bacterial etiology. Ninety-six (70.1%) of 137 samples suctioned from the hypopharynx through the nose were suitable for bacterial examination. Seventy-eight (73.6%) of 106 patients identified with causative bacteria had some underlying diseases, and the other 28 patients did not have any underlying diseases. Proportions and antibiotics susceptibility profiles of the identified causative bacteria were almost similar in the patients with and without underlying diseases. Sputum sampling from the hypopharynx through the nose might be significant in pediatric CA-LRTI of suspected bacterial etiology. The initial treatment for patients without underlying diseases would be applicable to those with underlying diseases in the CA-LRTI of children.

High mobility group box 1 (HMGB1) and macrophage migration inhibitory factor (MIF) in Kawasaki disease.

OBJECTIVE: To investigate whether two proinflammatory cytokines, high mobility group box 1 (HMGB1) and macrophage migration inhibitory factor (MIF) are involved in the development of Kawasaki disease (KD). METHODS: Twenty-seven patients with KD were included in this study. Eleven patients with sepsis and 28 healthy children served as controls. Serum levels of HMGB1 and MIF were measured by corresponding enzyme-linked immunosorbent assay (ELISA) kits, respectively. Real-time polymerase chain reaction (PCR) was used to quantify the expression levels of genes encoding receptor for advanced glycation end-products (RAGE), an HMGB1 receptor, and CD74, an MIF receptor in peripheral blood mononuclear cells (PBMCs). RESULTS: Serum levels of HMGB1 and MIF in KD patients were the highest in the early acute phase and gradually decreased after defervescence. Serum HMGB1 and MIF levels in KD patients were significantly higher than those in controls (HMGB1, p<0.001; MIF, p<0.01). The expression levels of the RAGE gene and CD74 gene in KD patients were significantly higher than those in controls (RAGE, p<0.001; CD74, p<0.01). CONCLUSION: These data suggest that HMGB1 and MIF play an important role in immune responses in KD patients.

Difference in response of NK cell activity in newborns and adult to IL-2, IL-12 and IL-15.

The killing activity of cord blood mononuclear cells (cMNC) against cytomegalovirus (CMV)-uninfected and -infected fibroblasts was comparable to that of adult peripheral blood mononuclear cells (aPBMC). The killing activity of cMNC against K562 cells was significantly lower compared with that of aPBMC. Treatment of cMNC and aPBMC with interleukin-2 (IL-2), IL-12 or IL-15 significantly enhanced killing activity against K562 cells and CMV-uninfected and -infected cells. By comparison of cMNC with aPBMC, killing activity against the K562 cells of cMNC was augmented to the level of aPBMC when cultured with IL-2, IL-12 or IL-15. The killing activity of cMNC against CMV-uninfected and -infected fibroblasts did not increase to the level of adult PBMC by treatment with IL-2, IL-12 or IL-15. These data suggest that cord blood contains a functionally different NK cell subpopulation than that among adult NK cells.