Causes of severe neonatal hyperbilirubinemia: a multicenter study of three regions in China.

BACKGROUND: Available evidence suggests that our country bear great burden of severe hyperbilirubinemia. However, the causes have not been explored recently in different regions of China to guide necessary clinical and public health interventions. METHODS: This was a prospective, observational study conducted from March 1, 2018, to February 28, 2019. Four hospitals in three regions of China participated in the survey. Data from infants with a gestational age ≥ 35 weeks, birth weight ≥ 2000 g, and total serum bilirubin (TSB) level ≥ 17 mg/dL (342 µmol/L) were prospectively collected. RESULTS: A total of 783 cases were reported. Causes were identified in 259 cases. The major causes were ABO incompatibility (n = 101), glucose-6-phosphate dehydrogenase deficiency (n = 76), and intracranial hemorrhage (n = 70). All infants with glucose-6-phosphate dehydrogenase deficiency were from the central south region. Those from the central south region had much higher peak total bilirubin levels [mean, 404 µmol/L; standard deviation (SD), 75 µmol/L] than those from the other regions (mean, 373 µmol/L; SD, 35 µmol/L) (P < 0.001). CONCLUSIONS: ABO incompatibility was the leading cause in the east and northwest regions, but cases in the central south region were mainly caused by both ABO incompatibility and glucose-6-phosphate dehydrogenase deficiency, and infants in this region had a much higher peak total bilirubin level. Intracranial hemorrhage may be another common cause. More thorough assessments and rigorous bilirubin follow-up strategies are needed in the central south region.

High-Temperature Molecular Ferroelectric Tris(2-hydroxyethyl) Ammonium Bromide with Dielectric Relaxation.

We obtained one new molecular ferroelectric material tris(2-hydroxyethyl) ammonium bromide (TAB) that crystallizes in aqueous solution at room temperature with a space group of R3m which belongs to ten polar space groups. There is a paraelectric-to-ferroelectric phase transition at 424 K (from hexagonal R3̅m to hexagonal R3m phase). Such a high transition temperature is close to that of diisopropylamine bromide (426 K) and higher than that of many other molecular ferroelectrics, such as triethylmethylammonium tetrabromoferrate(III) (360 K); some of the organic-inorganic perovskite ferroelectrics, such as (cyclohexylammonium)2PbBr4 (363 K); and some inorganic ferroelectrics, including BaTiO3 (393 K). The saturated polarization and the coercive field of TAB measured from the ferroelectric hysteresis loop are about 0.54 µC·cm-2 and 0.62 kV/cm, respectively. Given its superior performance, including high phase transition temperature, room-temperature ferroelectricity, small coercive electric field, and adjustable ladder-shaped dielectric constant, TAB will have many potential applications.

Ferroelectricity of the Orthorhombic and Tetragonal MAPbBr3 Single Crystal.

Hybrid organic-inorganic halide perovskites (HOIPs) MAPbBr3 and their ramifications have emerged because of the photovoltaic, optical, and other fascinating performances of HOIPs in recent years. However, many intrinsic properties, such as crystal structure and ferroelectricity, are still controversial. In this work, the ferroelectricity of the orthorhombic and tetragonal MAPbBr3 single crystal was confirmed through the dielectric behavior versus bias electric field ε( E), the temperature-dependent pyroelectric current with positive/negative poling, and the positive-up-negative-down (PUND) measurements. The electric field dependence of dielectric constant curves shows a butterfly type shape in the orthorhombic and tetragonal phase. The pyroelectric current shows two maxima at 155 and 245 K, corresponding to ferroelectric-ferroelectric and ferroelectric-paraelectric phase transitions, respectively. In particular, the direction of the pyroelectric current can be reversed by a positive or negative poling electric field, which is the assertive evidence of ferroelectricity. The PUND measurements act as the most convincing proof of the ferroelectricity of the MAPbBr3 single crystal. This work reports new evidence of the ferroelectric properties of the MAPbBr3 single crystal, which provides the intrinsic property when considering their high power conversion efficiencies.

Single molecule magnetic behaviour in lanthanide naphthalenesulfonate complexes.

The use of 2-naphthalenesulfonate (NAS) ligand in lanthanide chemistry afforded a family of isostructural mononuclear lanthanide complexes with the formula [Ln(NAS)2(H2O)6](NAS)·3H2O [Ln = Tb (1), Dy (2), Er (3), Yb (4)]. Crystallographic studies determined a square antiprismatic geometry (D4d) for the Ln centre and crystallization in an unprecedented chiral space group. The latter was further confirmed by the observation of Cotton effects in single crystal circular dichroism (CD) spectra. Static and dynamic magnetic measurements identified weak intermolecular dipolar interactions in 2, and such effects can be waived by dilution, which was noted by the detection of zero-field single molecule magnet (SMM) behaviour and hysteresis loop in a magnetically diluted sample (5). Compounds 2-4 exhibit SMM behaviours with energy barriers of 53, 32, and 45 K, respectively. To the best of our knowledge, these complexes are the first examples of pure 4f sulfonate-based SMMs.

Hypertriglyceridemic acute pancreatitis in emergency department: Typical clinical features and genetic variants.

OBJECTIVE: To investigate the clinical characteristics of patients with hypertriglyceridemic acute pancreatitis (HTGAP), and the molecular foundation contributing to hypertriglyceridemia in such patients. METHODS: Clinical data from 329 patients with acute pancreatitis (AP) were analyzed. The patients were divided into the HTGAP group, with fasting serum triglyceride (TG) levels ≥500 mg/dL (5.65 mmol/L), and the non-HTGAP (NHTGAP) group. Targeted next-generation sequencing was applied to 11 HTGAP patients to identify the genetic mutations associated with hypertriglyceridemia, including apolipoprotein A-V (APOA5), APOC2, APOC3 and APOE, BLK, LPL, GPIHBP1 and LMF1. RESULTS: Patients in the HTGAP group, compared with those in the NHTGAP group, had a higher mortality rate (7.5% vs 0.7%, P = 0.001), more commonly seen severe AP (17.5% vs 5.2%, P = 0.004) as well as a higher recurrence rate (32.4% vs 19.9%, P = 0.070). DNA sequencing showed that two patients carried the same compound of p.G185C and p.V153M heterozygous mutations located in the APOA5 gene. Two patients carried a homozygous variation of p.C14F, in the GPIHBP1 gene. One patient had a homozygous variation of p.R176C in the APOE gene. And a rare heterozygous LMF1 gene mutation of p.P562R was detected in two patients. CONCLUSIONS: HTGAP was significantly severe than NHTGAP, with a high recurrence rate. Genetic information may be useful in the clinical setting for the investigation of the pathogenesis of HTGAP and its interventions.

[Influence of delayed cord clamping on preterm infants with a gestational age of <32 weeks].

OBJECTIVE: To investigate the influence of delayed cord clamping (DCC) on preterm infants with a gestational age of <32 weeks. METHODS: Ninety preterm infants with a gestational age of <32 weeks delivered naturally from January to December, 2015 were enrolled and randomly divided into DCC group (46 infants) and immediate cord clamping (ICC) group (44 infants). The routine blood test results, total amount of red blood cell transfusion, blood gas parameters, mean arterial pressure, bilirubin peak, total time of phototherapy, and incidence rates of necrotizing enterocolitis, late-onset sepsis, intracranial hemorrhage, retinopathy, and bronchopulmonary dysplasia were compared between the two groups. RESULTS: Compared with the ICC group, the DCC group had significantly higher levels of hemoglobin, hematocrit, mean arterial pressure, and standard base excess (P<0.05), as well as a significantly lower percentage of preterm infants who underwent volume expansion and dopamine treatment and a significantly lower amount of red blood cell transfusion (P<0.05). The body temperature, pH value, HCO3(-) concentration, serum bilirubin peak, total time of phototherapy, and incidence rates of late-onset sepsis, retinopathy, grade≥2 intracranial hemorrhage, and grade≥2 neonatal necrotizing enterocolitis showed no significant differences between the two groups (P>0.05). CONCLUSIONS: DCC is a safe clinical intervention and can improve the prognosis of preterm infants with a gestational age of <32 weeks.

[Rapid diagnosis of Down's and Edward's syndrome by multiplex real-time quantitative PCR].

OBJECTIVE: To establish a multiplex real-time quantitative PCR method for diagnosis of Down's and Edward's syndrome. METHODS: The sequences of the amyloid precursor protein gene (APP) in the Down's region of chromosome 21 and the thymidylate synthetase gene (TYMS) on chromosome 18 were co-amplified in the same tube. The relative quantitative index DeltaCT value was used to differentiate Down's and Edward's syndrome patient from healthy individual. Four groups of samples, including 36 blood samples from normal controls (group A), 15 amniotic fluid samples from normal pregnancies (group B), 21 samples from patients with Down's syndrome (group C) and 6 samples from patients with Edward's syndrome (group D), were investigated in the study. RESULTS: The mean DeltaCT values of the four groups were -0.48+/-0.15, -0.49+/-0.12, -1.26+/-0.17 and 0.25+/-0.12 respectively. The DeltaCT value from group B was not different from that from group A (P>0.05). However, the DeltaCT values from group C and group D were significantly different from that from group A (P<0.01), and no overlapping was observed. CONCLUSION: The DeltaCT values from multiplex real-time quantitative PCR could be used to rapidly diagnose Down's and Edward's syndrome simultaneously.