Collective dynamics of liquid sulphur across the polymerisation transition temperature probed by inelastic x-ray scattering.

Inelastic x-ray scattering (IXS) experiments on liquid sulphur were carried out below (140◦C) and above (180◦C) the polymerisation temperature Tλ of about 159◦C to investigate changes in the collective dynamics of this unique liquid, that exhibits a liquid‒liquid transition. As reported earlier, broad longitudinal acoustic excitation signals were observed at both temperatures, and only the width of the quasielastic peaks slightly decreased when the temperature crossed the transition temperature. A model analysis was performed using a generalised Langevin formalism with a memory function having one thermal and two viscoelastic decay channels with the help of simple sparse modelling, and large positive deviations from the hydrodynamic sound velocity by 51‒54% were observed. The fast viscoelastic relaxation time τµis close to the correlation times of intermolecular stretching and bending motions of local sulphur connections in both ring and chain structures, and is similar to those of other molecular liquids. The small contrasts in the IXS spectra across the λ transition result in large changes in only the slow viscoelastic decay time τα of the memory function. The τα value at 140◦C matches the mixed internal/external torsional modes of S8 molecules well, whereas that at 180◦C has no corresponding molecular motion mode. The kinematic viscosity values at thesmaller than the minimum values of macroscopic shear viscosity, in⃗dicating that largeQ 0 limit are much changes in relaxation dynamics are expected with Q in the GHz and MHz excitation regimes. .

Severe Hemolytic Anemia and Metabolic Acidosis at Birth with Glutathione Synthetase Deficiency and Progressive Neurological Symptoms on Follow-Up.

BACKGROUND Glutathione synthetase deficiency (GSD) is a rare autosomal recessive disorder caused by glutathione synthetase (GSS) gene variants that occur in 1 in 1 million individuals. The severe form of GSD is characterized by hemolytic anemia, metabolic acidosis with 5-oxoprolinuria, progressive neurological symptoms, and recurrent bacterial infections. This case report presents a male Japanese infant with severe hemolytic anemia and metabolic acidosis at birth caused by GSD, who developed progressive neurological symptoms on follow-up. CASE REPORT A Japanese male term infant developed severe hemolytic anemia and metabolic acidosis in the early neonatal period. We suspected GSD based on his symptoms and a high 5-oxoproline urine concentration. We began correcting his metabolic acidosis and administering vitamins C and E supplements. The patient required blood transfusion twice during the acute phase for hemolytic anemia. After age 1 month, he maintained good control of metabolic acidosis and hemolytic anemia. A definitive diagnosis of GSD was made based on high concentrations of 5-oxoproline in urine, low concentrations of glutathione and GSS activity in erythrocytes, and genetic testing. Several episodes of febrile convulsions were started at age 11 months, but none occurred after 2 years. At the last follow-up at age 25 months, metabolic acidosis and hemolytic anemia were well controlled, but he had mild neurodevelopmental delay. CONCLUSIONS This case report shows that GSD can present with severe hemolytic anemia and metabolic acidosis at birth, and manifest with subsequent neurological impairment despite early diagnosis and treatment. Therefore, a careful long-term follow-up that includes neurological evaluation is essential for patients with GSD.

Effect of nasal mupirocin treatment on extranasal carriage of methicillin-resistant Staphylococcus aureus among pediatric patients admitted to the neonatal intensive care unit.

Decolonization of MRSA detected in the oral cavity and tracheal aspirates occurred in 85% and 58% of neonates, respectively, with nasal mupirocin treatment. Recurrent MRSA colonization occurred in 45% of neonates whose MRSA was detected in the oral cavity at a mean of 19 days. Recurrent MRSA colonization occurred in 58% of neonates whose MRSA was detected in tracheal aspirates at a mean of 23 days.

Ion solvation and association and water structure in an aqueous cerium (III) chloride solution in the gigapascal pressure range.

X-ray diffraction measurements are performed on a 1 m (= mol kg-1) CeCl3 aqueous solution over a temperature range of 300-600 K and a pressure range of 0.1 MPa to 4 GPa. The experimental interference functions are analyzed by an empirical potential structure refinement (EPSR) modeling. The Ce3+ coordinates water molecules in a tricapped trigonal prism configuration under the ambient condition. The number of water molecules around Ce3+ changes from 8.8 at 0.1 MPa/300 K to 11.5 at 4 GPa/600 K. The number of water molecules around Cl- changes drastically from 10 under the ambient condition to 17 at 4 GPa/600 K. The tetrahedral-like network structure of water under the ambient condition is transformed toward a simple liquid-like packing in the GPa pressure range. The corresponding coordination number is increased from 4.3 in the ambient condition to 9.7 at 4 GPa/600 K. The Ce3+-Cl- association decreases with increasing pressure.

Epidemiology of group B streptococcal disease in infants younger than 1 year in Japan: a nationwide surveillance study 2016-2020.

We aimed to define the burden and clinical features of invasive group B streptococcus (GBS) disease in infants younger than 1 year in Japan, to explore transmission route of late-onset disease (LOD), and to identify risk factors associated with recurrent GBS disease. We conducted a retrospective, questionnaire-based nationwide surveillance study between 2016 and 2020. A total of 875 GBS cases were identified, including 186 early-onset disease, 628 LOD, and 61 ultra-late-onset disease. Case fatality rate in each age category was 6.5%, 3.0%, and 3.3%, respectively. Patients with meningitis had neurodevelopmental sequelae in 21.5% (64/297). Annual incidence in infants younger than 1 year and in LOD significantly increased from 0.28 to 0.45/1000 livebirths (p = 0.021) and from 0.19 to 0.29/1000 livebirths (p = 0.046), respectively. Maternal colonization status at the LOD diagnosis was available for 148 mothers, of whom 21/58 (36.2%) had positive rectovaginal swabs and 42/117 (36.2%) had GBS in breastmilk culture. These two sites are potentially infectious routes in LOD. The four leading disease-causing serotypes III, Ia, Ib, and V represented 95% of the available serotypes. Thirty-one recurrent cases were identified, accounting for 3.7% of total patients. A multivariate regression analysis showed that prematurity (p = 0.029) and antepartum maternal GBS colonization (p = 0.032) were significantly associated with risk for the recurrence. Our findings indicated that GBS disease burden still remains with considerable mortality and morbidity in Japan, and provided important information for developing better strategies for the prevention of GBS disease, including maternal vaccination.

Effect of oral care in reducing the incidence of early-onset ventilator-associated pneumonia in preterm infants.

BACKGROUND: Oral care using chlorhexidine has been considered useful in reducing the incidence of ventilator-associated pneumonia (VAP) in adult patients. However, no study has proved the effect of oral care in reducing the incidence of VAP in preterm infants. OBJECTIVES: To investigate the efficacy of oral care using a sponge brush moistened with sterile water in reducing the bacterial load in the oral cavity and the incidence of early-onset VAP in preterm infants METHODS: The bacterial number in the oral cavity was evaluated on-site with the dielectrophoretic impedance measurement system. Bacterial numbers before and after oral care were investigated prospectively. Then, the incidence of early-onset VAP was compared retrospectively between infants who received oral care before re-intubation and those who did not. RESULTS: The mean bacterial number (cfu/ml) in the oral cavity in infants managed with endotracheal intubation (n = 23), continuous positive airway pressure (n = 38), and high-flow nasal cannula (n = 22) significantly reduced (p < .01) after versus before oral care (4.46 × 107 vs. 1.25 × 106 ; 1.32 × 107 vs. 6.82 × 105 ; and 1.68 × 107 vs. 6.50 × 105 ). The incidence rate of early-onset VAP after re-intubation was 51% (20/39) in patients who did not receive oral care. Then, it significantly decreased to 21% (7/33; p = .009) after receiving oral care. CONCLUSION: Oral care with sterile water may be effective in reducing the bacterial load in the oral cavity and the incidence of early-onset VAP in preterm infants.

Ion Solvation and Water Structure in an Aqueous Sodium Chloride Solution in the Gigapascal Pressure Range.

The structure of a 3 m (= mol/kg) NaCl aqueous solution at 1.3 and 1.7 GPa and 300 K, as well as at an ambient condition, is determined by synchrotron X-ray diffraction measurements combined with an empirical potential structure refinement (EPSR) modeling. When the solution is pressurized to the gigapascal pressure range, the ice-like hydrogen-bonded water network at 300 K/0.1 MPa is drastically perturbed to give rise to a simple, liquid-like water molecules arrangement retaining the hydrogen bonds. The coordination number of the chloride ion increases from around 6 at 0.1 MPa to about 16 at 1.7 GPa, accompanied by the extended solvation shells' evolution. On the other hand, the sodium ion's solvation structure does not change significantly with pressure and consists of 6-fold water molecules' coordination. We discuss a structure makers/breakers' concept for the ion solvation concerning the water structure in the gigapascal pressure range.

Evaluation index for asymmetric ventricular size on brain magnetic resonance images in very low birth weight infants.

OBJECTIVE: Asymmetric ventriculomegaly is often evident on brain magnetic resonance imaging (MRI) in very low birth weight infants (VLBWI) and is interpreted as white matter injury. However, no evaluation index for asymmetric left-right and anterior-posterior ventricular sizes has been established. METHODS: In this retrospective multicenter cohort study, brain T2-weighted MRI was performed at term-equivalent ages in 294 VLBWI born between 2009 and 2011. The value of a lateral ventricular index (LVI) to evaluate asymmetric ventricular size, as well as the relationship between the LVI value and walking at a corrected age of 18 months was investigated. At the level of the foramen of Monro in a horizontal slice, asymmetry between the left and right sides and between the anterior and posterior horns was identified by the corrected width and was detected by a low concordance rate and κ statistic value. An LVI representing the sum of the widths of the four horns of the lateral ventricle corrected for cerebral diameter was devised. RESULTS: Asymmetric left-right and anterior-posterior ventricular sizes were confirmed. The LVI value was significantly higher in the non-walking VLBWI group (n = 39) than in the walking VLBWI group (n = 255; 18.2 vs. 15.8, p = 0.02). An LVI cut-off value of 21.5 was associated with non-walking. Multivariate analysis revealed that an LVI value >21.5 was an independent predictor of walking disability at the corrected age of 18 months (odds ratio 2.56, p = 0.008). CONCLUSIONS: The LVI value calculated via MRI may predict walking disability at a corrected age of 18 months in VLBWI.

Transcutaneous bilirubin measurement during phototherapy in term neonates.

BACKGROUND: We tested whether direct transcutaneous bilirubin (TcB) measurement from an area unexposed to phototherapy is reliable for estimation of total serum bilirubin (TSB) in neonates during phototherapy and whether it contributes to reduction in TSB blood sampling in phototherapy decision making. METHODS: This was a retrospective observational study of term neonates who received phototherapy in the mother's room. TSB and TcB from the neonate's sternum were measured before and during phototherapy and compared using linear regression analysis and Bland-Altman plot, respectively. Various cut-offs of TcB for estimating TSB during phototherapy at >72 h after birth were analyzed. RESULTS: There were moderate correlations between TSB and TcB before (r = 0.56) and during (r = 0.47) phototherapy in 125 neonates. The mean difference (TSB-TcB) before and during phototherapy was 1.2 ± 1.7 mg/dL and 1.0 ± 1.7 mg/dL, respectively. The 95% limits of agreement for the difference before and during phototherapy ranged from -2.1 to 4.5 and from -2.3 to 4.3 mg/dL, respectively. For TSB ≤18 mg/dL during phototherapy, a TcB cut-off of 14 mg/dL had a specificity of 1.0; with this method, 43% of the TSB measurements could have been avoided. CONCLUSIONS: Direct measurement of TcB during phototherapy using a bed-type device is a reliable method to estimate TSB in term neonates and would contribute to a reduction in blood sampling. It cannot, however, be used as a substitute for TSB measurement.

Effect of Volume Guarantee in Preterm Infants on High-Frequency Oscillatory Ventilation: A Pilot Study.

Objectives Although adding volume guarantee (VG) to conventional ventilation has been a well-established respiratory management for preterm infants, the evidence of VG combined with high-frequency oscillatory ventilation (HFOV) has not been studied well. The aim of this study was to investigate the effect of VG added to HFOV on respiratory and other physiological parameters. Methods We conducted a pilot study in extremely low-birth-weight infants ventilated with HFOV + VG with stable pulmonary status after 28 days of age. VG was applied for 6 hours and removed for the following 6 hours, and data were collected during these 12 hours. Results Six neonates were included in this study (gestational age: 22w5d-23w6d, birthweight: 424-584 g). High-frequency expired tidal volume per weight and amplitude were similar between periods with and without VG. Fluctuation of SpO2, but not heart rate, was significantly smaller when babies were ventilated with VG than without VG. Fluctuation of minute volume and carbon dioxide diffusion coefficient significantly increased after VG removal. The proportion of time with SpO2 < 80% was decreased by VG overall, especially in three cases. Conclusion This pilot study suggests VG combined with HFOV attenuates fluctuation of SpO2 and CO2 clearance, which may prevent hypoxemia and hypocapnia.

Acquired palatal groove and delayed oral feeding in preterm infants.

BACKGROUND: Acquired palatal groove has been reported in the 1970s and 1980s, but its current incidence in Japanese newborns is unclear. The aims of this study were to determine the incidence of palatal groove in preterm infants and to evaluate whether this condition affects oral feeding ability. METHODS: We conducted a prospective observational study among very low-birthweight infants born at Takatsuki General Hospital, Osaka, between March and October in 2010. The shape of the hard palate was classified into three types: normal, narrow high-arched palate, and palatal groove. RESULTS: Among the 37 enrolled infants, 14 (38%) had palatal groove. In particular, among the 29 infants with birthweight <1000 g, palatal groove was observed in 48% of these patients, and only 10% were normal. Infants with palatal groove were ventilated for considerably more days with oral endotracheal tube than those without palate groove, even after adjustment for gestational age, birthweight, and duration of oral duodenal tube placement (OR, 1.11). Establishment of oral feeding and disappearance of choking on milk were considerably delayed in infants with palatal groove. Transient oral feeding difficulty requiring thickened-feed intervention was observed only in infants with palatal groove; on multi-regression analysis this difficulty seemed to be induced by the palatal groove. CONCLUSIONS: Palatal groove formation induced by oral endotracheal intubation occurs with a high frequency in preterm infants, and this is likely to affect oral feeding ability.

Reliability of Total Bilirubin Measurements in Whole Blood from Preterm Neonates Using a Blood Gas Analyzer.

BACKGROUND: Blood gas analyses are usually required more frequently in preterm neonates than in term neonates. If total bilirubin (TB) levels in whole blood measured using a blood gas analyzer are reliable, blood sampling for total serum bilirubin (TSB) levels alone can be reduced in preterm neonates. We investigated the reliability of measuring TB levels in whole blood from preterm neonates using the latest generation blood gas analyzer. METHODS: TB measured on an ABL90 FLEX blood gas analyzer and TSB analyzed in the hospital laboratory were simultaneously analyzed. TB and TSB levels (300 data sets in 85 preterm neonates) were compared using linear regression and Bland-Altman difference plots. RESULTS: Concordance correlation coefficient analysis showed a strong relationship between TB and TSB levels (a CCC value of 0.94) with a Pearson's coefficient of 0.97 and a bias correction of 0.97. Bland-Altman difference p lots demonstrated that, on average, TB tended to underestimate the TSB, with a mean (95% confidence interval) bias of -0.7 (-0.6 to -0.8) mg/dL. CONCLUSIONS: Whole blood TB levels measured using an ABL90 FLEX are reliable and can lead to a reduction in blood sampling for TSB in preterm neonates.

Screening for Hyperbilirubinemia in Japanese Very Low Birthweight Infants Using Transcutaneous Bilirubinometry.

OBJECTIVES: To assess the accuracy of transcutaneous bilirubin (TcB) measurements at 5 different body sites in Japanese very low birthweight (VLBW) infants and to determine a cut-off value of TcB to detect total serum/plasma bilirubin (TB) levels ≥10 mg/dL (171 µM). STUDY DESIGN: In a prospective multicenter study, 85 Japanese VLBW infants were enrolled from 5 neonatal intensive care units during the study period. A total of 383 blood samples from infants not receiving phototherapy or ≥24 hours postphototherapy were analyzed. TcB was measured at the forehead, sternum, upper back, lower abdomen, and waist within 1 hour of blood collection. Linear regression analysis and Bland-Altman plots were used to compare TcB values at each site with TB levels. The TcB cut-off value for detecting TB ≥10 mg/dL was determined by receiver operating characteristics curve analysis. RESULTS: TcB significantly correlated with TB, but the coefficient of determination varied among the sites (forehead: 0.5294, sternum: 0.6488, upper back: 0.6321, lower abdomen: 0.5430, waist: 0.7396). At a TcB value ≥8, the sensitivity was 100% at the sternum and upper back, 85% at the waist, 84% at the forehead, and 64% at the lower abdomen to detect TB ≥10 mg/dL. CONCLUSIONS: In Japanese VLBW infants, the accuracy of TcB measurements varies according to body site. TcB ≥8 on the sternum or upper back is more reliable than that on the forehead, lower abdomen, or waist to detect TB levels ≥10 mg/dL.

Current incidence of clinical kernicterus in preterm infants in Japan.

Clinical kernicterus in preterm infants has recently been reported in Japan, diagnosed on the basis of clinical findings during the neonatal and infancy periods. We investigated the incidence of clinical kernicterus in preterm infants <30 weeks gestational age (GA) based on a nationwide survey conducted in 233 certified educational facilities for neonatologists. The numbers of infants admitted and infants who died within 14 days after birth during 2011, and the number of infants who subsequently developed clinical kernicterus, were recorded. A total of 2720 infants were analyzed, representing 59% (2720/4623) of all preterm live births <30 weeks GA in Japan in 2011. Of these, 159 (5.8%) died within 14 days after birth, similar to the national rate. Five infants developed clinical kernicterus in infancy (5/2720, 0.18%). The current incidence of clinical kernicterus in Japan is therefore estimated at 1.8 per 1000 live births <30 weeks GA.

Serum unbound bilirubin as a predictor for clinical kernicterus in extremely low birth weight infants at a late age in the neonatal intensive care unit.

BACKGROUND: This study aimed to evaluate peak serum total bilirubin (TB) and unbound bilirubin (UB) levels in preterm infants with clinical kernicterus (KI) who were diagnosed by clinical findings during infancy. DESIGN/SUBJECTS: For this multicenter retrospective study, 18 Japanese extremely low birth weight (ELBW) infants with clinical KI were included. Clinical KI was diagnosed based on the presence of motor developmental impairment with/without athetosis, and abnormal magnetic resonance imaging or brainstem auditory evoked potential findings during infancy. High and low TB or UB levels were defined as serum TB levels ⩾ and <15 mg/dL or serum UB levels ⩾ and <0.8 µg/dL, respectively. The clinical characteristics of KI preterm infants were analyzed. The proportion of infants with high or low serum TB levels and with high or low serum UB levels was then investigated. Sensitivity and specificity were calculated. RESULTS: In 18 KI infants, the median age when serum TB levels peaked was 28 days after birth. In eight KI infants with low serum TB levels, 88% of them had high serum UB levels. For comparison of the number of infants who had high or low serum TB and UB levels, the sensitivity was 90% and specificity was 13%. CONCLUSIONS: Serum TB and UB levels peak at a later age than expected. Chronic serum UB monitoring may be helpful for identifying ELBW infants at risk for developing KI, even when they do not have high serum TB levels.

Association of HMOX1 gene promoter polymorphisms with hyperbilirubinemia in the early neonatal period.

BACKGROUND: Heme oxygenase (HO) is the rate-limiting enzyme in the heme degradation pathway that produces bilirubin. The promoter region of human heme oxygenase-1 (HMOX1) contains a polymorphic (GT)n repeat that can regulate gene expression. Here, we investigated the association of (GT)n repeat length in the HMOX1 promoter region with neonatal hyperbilirubinemia in a population of Japanese term neonates. METHODS: Using polymerase chain reaction and fragment analysis, we determined the number of (GT)n repeats in 149 Japanese neonates. To omit the effects of the G71R mutation in uridine diphosphoglucuronosyltransferase on hyperbilirubinemia, we excluded 41 neonates with the G71R mutation. As a result, 25 neonates with hyperbilirubinemia and 83 non-hyperbilirubinemic controls were included in this prospective case-control study. Allele and genotype frequencies of (GT)n repeats in the HMOX1 gene were compared between hyperbilirubinemic and non-hyperbilirubinemic control neonates. RESULTS: The prevalence of short alleles (< 22 (GT)n repeats) was significantly higher in hyperbilirubinemic than in control neonates (18% vs 7%, P = 0.015). Hyperbilirubinemia was more frequent in homozygous or heterozygous short allele carriers than control neonates (28% vs 11%, respectively, P = 0.03). Possession of short alleles was significantly associated with the development of neonatal hyperbilirubinemia (OR, 3.1; 95%CI: 1.03-9.53). CONCLUSIONS: Infants carrying short alleles (< 22 (GT)n repeats) in the HMOX1 gene promoter region appear to be at a higher risk for developing neonatal hyperbilirubinemia.

Site occupancy of interstitial deuterium atoms in face-centred cubic iron.

Hydrogen composition and occupation state provide basic information for understanding various properties of the metal-hydrogen system, ranging from microscopic properties such as hydrogen diffusion to macroscopic properties such as phase stability. Here the deuterization process of face-centred cubic Fe to form solid-solution face-centred cubic FeDx is investigated using in situ neutron diffraction at high temperature and pressure. In a completely deuterized specimen at 988 K and 6.3 GPa, deuterium atoms occupy octahedral and tetrahedral interstitial sites with an occupancy of 0.532(9) and 0.056(5), respectively, giving a deuterium composition x of 0.64(1). During deuterization, the metal lattice expands approximately linearly with deuterium composition at a rate of 2.21 Å(3) per deuterium atom. The minor occupation of the tetrahedral site is thermally driven by the intersite movement of deuterium atoms along the direction in the face-centred cubic metal lattice.

High-dose calcium reduces early-onset hyperkalemia in extremely preterm neonates.

BACKGROUND: Early-onset hyperkalemia often occurs in extremely preterm infants during a few days after birth. While there are several treatments for hyperkalemia, calcium infusion to reduce plasma potassium concentrations remains controversial. The purpose of this study is to investigate whether a high dosage of calcium reduces early-onset hyperkalemia. METHODS: Extremely low-birthweight neonates born at 22-25 weeks' gestation were enrolled. We analyzed data using multivariate regression analysis and performed a retrospective cohort study with patients divided into two groups according to the dosage of calcium in their initial infusion. RESULTS: A total of 103 patients were eligible. Early-onset hyperkalemia was observed in 27 patients. The dosage of calcium gluconate during 24 h after birth was the only independent factor affecting early-onset hyperkalemia. The maximum plasma potassium concentration during 72 h after birth was negatively correlated with the dosage of calcium. High-dose calcium reduced occurrences of hyperkalemia and hypoglycemia caused by insulin infusion given for treatment of hyperkalemia, without increasing the risk of any other complications. CONCLUSIONS: Infusion of calcium gluconate may reduce early-onset hyperkalemia in a dose-dependent manner.

Communication: probable scenario of the liquid-liquid phase transition of SnI4.

We have shown from in situ synchrotron x-ray diffraction measurements that there are two thermodynamically stable liquid forms of SnI(4), depending on the pressure. Based on the liquid-liquid critical point scenario, our recent measurements suggest that the second critical point, if it exists, may be located in a region close to the point at which the melting curve of the crystalline phase abruptly breaks. This region is, unlike that of water, experimentally accessible with relative ease.

Evaluation system for minor nervous dysfunction by pronation and supination of forearm using wireless acceleration and angular velocity sensors.

We developed a simple, portable and easy system to the motion of pronation and supination of the forearm. This motion was measured by wireless acceleration and angular velocity sensor. The aim of this system is evaluation of minor nervous dysfunction. It is for the screening of the developmental disorder child. In this study, in order to confirm the effectiveness of this system, the reference curve of the neuromotor development was experimentally obtained. We studied 212 participants (108 males, 104 females) aged 7 to 12 years attending the kindergarten school. We could obtain the reference curve of the neuromotor development using this system. We also investigated the difference of neuromotor function between normally developed children and a ADHD child. There is a possibility that abnormality of the minor nervous dysfunction can be detected by using this system.