Bis-oxazoline derivatives as ancillary ligands for bis-cyclometalated iridium complexes.

Organometallic iridium complexes with two cyclometalated ligands (CN) and one bis-oxazoline derived ancillary ligand (L^X), i.e. (CN)2Ir(L^X), are reported. The CN ligands are 1-phenylpyrazoline (ppz), 2-(4,6-difluorophenyl)pyridine (F2ppy), 2-phenylpyridine (ppy), 1-phenylisoquinoline (piq). The box ligand is (4S)-(+)-phenyl-α-[(4S)-phenyloxazolidin-2-ylidene]-2-oxazoline-2-acetonitrile. The emission of these complexes span across the visible and into the near-ultraviolet region of the electromagnetic spectrum with moderate to high photoluminescence quantum yields (ΦPL = 0.45-1.0). These complexes were found to emit from a metal-ligand to ligand charge transfer (ML'LCT) state and have lifetimes (1.3-2.1 µs), radiative rates (105 s-1), and nonradiative rates (104-105 s-1) comparable to state-of-the-art iridium emitters. The (ppy)2Ir(BOX-CN) complexes were resolved into the Δ- and Λ- diastereomers using differences in their solubility and additionally characterized by x-ray crystallography, stability, and chiroptic studies. The high ΦPL of these isomers results in the best to date brightness for circularly polarized luminescence (CPL) from iridium complexes (7.0 M-1 cm-1), with dissymmetry factors of -0.57 × 10-3 and +1.9 × 10-3 for 3Δ and 3Λ, respectively. The significant difference in CPL magnitude between 3Δ and 3Λ likely arises from interligand interactions (edge-to-face arrangement versus strong π-π interaction) for the pendant phenyl ring of the BOX-CN ligand which differ for the two isomers.

[A preliminary study on a new method for evaluating brain maturation in preterm infants]. / ä¸€ç§æ–°çš„æ—©äº§å„¿è„‘ç”µå‘è‚²æˆç†Ÿåº¦è¯„ä»·æ–¹æ³•çš„åˆæ­¥ç ”ç©¶.

OBJECTIVES: To establish a new method for evaluating the brain maturation of preterm infants based on the features of electroencephalographic activity. METHODS: A prospective study was conducted on the video electroencephalography (vEEG) and amplitude-integrated electroencephalography (aEEG) recordings within 7 days after birth of preterm infants who had a postmenstrual age (PMA) of 25-36 weeks and met the inclusion criteria. The background activity of aEEG+conventional electroencephalography (cEEG) was scored according to the features of brain maturation as a new evaluation system and was compared with the aEEG evaluation system. The correlations of the evaluation results of the two methods with gestational age (GA), PMA, and head circumference were evaluated. The intervals of the total scores of aEEG+cEEG and aEEG were calculated for preterm infants with different PMAs and were compared between groups. The consistency of the new scoring system was evaluated among different raters. RESULTS: A total of 52 preterm infants were included. The total scores of aEEG+cEEG and aEEG were positively correlated with GA, PMA, and head circumference (P<0.05), and the correlation coefficient between the total scores of the two systems and PMA and GA was >0.9. The normal score intervals for aEEG+cEEG and aEEG scoring systems were determined in preterm infants with different PMAs as follows: infants with a PMA of less than 28 weeks had scores of 13.0 (11.0, 14.0) points for aEEG+cEEG and 6.0 (4.0, 7.0) points for aEEG; infants with a PMA between 28 and 29+6 weeks had scores of 16.0 (14.5, 17.0) points for aEEG+cEEG and 8.0 (6.0, 8.0) points for aEEG; infants with a PMA between 30 and 31+6 weeks had scores of 18.0 (17.0, 21.0) points for aEEG+cEEG and 9.0 (8.0, 10.0) points for aEEG; infants with between 32 and 33+6 weeks had scores of 22.0 (20.0, 24.5) points for aEEG+cEEG and 10.0 (10.0, 10.8) points for aEEG; infants with a PMA between 34 and 36 weeks had scores of 26.0 (24.5, 27.5) points for aEEG+cEEG and 11.0 (10.0, 12.0) points for aEEG. There were significant differences in the total scores of aEEG+cEEG and aEEG among the different PMA groups (P<0.05). There was a high consistency between different raters when using the scoring system to evaluate the brain maturation of preterm infants (κ=0.86). CONCLUSIONS: The aEEG+cEEG scoring system established in this study can quantitatively reflect the brain maturation of preterm infants, with a good discriminatory ability between preterm infants with different PMAs and high consistency between different raters.

[A novel method for electroencephalography background analysis in neonates with hypoxic-ischemic encephalopathy]. / åº”ç”¨äºŽæ–°ç”Ÿå„¿ç¼ºæ°§ç¼ºè¡€æ€§è„‘ç— çš„è„‘ç”µèƒŒæ™¯åˆ†æžæ–°æ–¹æ³•.

OBJECTIVES: To explore a new method for electroencephalography (EEG) background analysis in neonates with hypoxic-ischemic encephalopathy (HIE) and its relationship with clinical grading and head magnetic resonance imaging (MRI) grading. METHODS: A retrospective analysis was performed for the video electroencephalography (vEEG) and amplitude-integrated electroencephalography (aEEG) monitoring data within 24 hours after birth of neonates diagnosed with HIE from January 2016 to August 2022. All items of EEG background analysis were enrolled into an assessment system and were scored according to severity to obtain the total EEG score. The correlations of total EEG score with total MRI score and total Sarnat score (TSS, used to evaluate clinical gradings) were analyzed by Spearman correlation analysis. The total EEG score was compared among the neonates with different clinical gradings and among the neonates with different head MRI gradings. The receiver operating characteristic (ROC) curve and the area under thecurve (AUC) were used to evaluate the value of total EEG score in diagnosing moderate/severe head MRI abnormalities and clinical moderate/severe HIE, which was then compared with the aEEG grading method. RESULTS: A total of 50 neonates with HIE were included. The total EEG score was positively correlated with the total head MRI score and TSS (rs=0.840 and 0.611 respectively, P<0.001). There were significant differences in the total EEG score between different clinical grading groups and different head MRI grading groups (P<0.05). The total EEG score and the aEEG grading method had an AUC of 0.936 and 0.617 respectively in judging moderate/severe head MRI abnormalities (P<0.01) and an AUC of 0.887 and 0.796 respectively in judging clinical moderate/severe HIE (P>0.05). The total EEG scores of ≤6 points, 7-13 points, and ≥14 points were defined as mild, moderate, and severe EEG abnormalities respectively, which had the best consistency with clinical grading and head MRI grading (P<0.05). CONCLUSIONS: The new EEG background scoring method can quantitatively reflect the severity of brain injury and can be used for the judgment of brain function in neonates with HIE.

Correlation of electroencephalogram background evolution with the degree of brain injury in neonates with hypoxic-ischemic encephalopathy. / æ–°ç”Ÿå„¿ç¼ºæ°§ç¼ºè¡€æ€§è„‘ç— è„‘ç”µèƒŒæ™¯æ¼”å˜ä¸Žè„‘æŸä¼¤ç¨‹åº¦çš„ç›¸å ³æ€§ç ”ç©¶.

OBJECTIVES: To study the correlation of electroencephalogram (EEG) background evolution with the degree of brain injury in neonates with hypoxic-ischemic encephalopathy (HIE). METHODS: A retrospective analysis was performed for 56 neonates with HIE who underwent continuous video electroencephalogram (cVEEG) and brain magnetic resonance imaging (MRI) examinations. According to clinical symptoms, they were divided into a mild group with 3 neonates, a moderate group with 36 neonates, and a severe group with 17 neonates. EEG background grading and MRI score were determined for each group to analyze the correlation of EEG background evolution with the degree of brain injury. RESULTS: Compared with the moderate group, the severe group had significantly lower gestational age and Apgar score at 5 minutes after birth, a significantly higher resuscitation score, significantly lower base excess in umbilical cord blood or blood gas within 1 hour, a significantly higher proportion of neonates on mechanical ventilation, and a significantly higher incidence rate of short-term adverse outcomes (P<0.05). For the neonates in the mild and moderate groups, MRI mainly showed no brain injury (67%, 2/3) and watershed injury (67%, 16/24) respectively, and EEG showed mild abnormality in 62% (13/21) of the neonates on the 3rd day after birth. For the neonates in the severe group, MRI mainly showed basal ganglia/thalamus + brainstem injury (24%, 4/17) and whole brain injury (71%, 12/17), and EEG showed moderate or severe abnormalities on the 3rd day after birth. EEG background grading was correlated with clinical grading, MRI score, and short-term outcome on days 1, 2, 3 and 7-14 after birth (P<0.01). The highest correlation coefficient between EEG grading and MRI score was observed on the 3rd day after birth (rs=0.751, P<0.001), and the highest correlation coefficients between EEG grading and clinical grading (rs=0.592, P=0.002) and between EEG grading and short-term outcome (rs=0.737, P<0.001) were observed 7-14 days after birth. Among the neonates with severe abnormal EEG, the neonates without brain electrical activity had the highest MRI score, followed by those with status epileptics and persistent low voltage (P<0.05). CONCLUSIONS: There is a good correlation between EEG background grading and degree of brain injury in neonates with HIE, which can help to evaluate the degree and prognosis of brain injury in the early stage.

Association of PLA2G7 gene polymorphisms with ischemic stroke in northern Chinese Han population.

OBJECTIVE: Human lipoprotein-associated phospholipase A2 (Lp-PLA2), encoded by the PLA2G7 gene, plays an important role in the pathophysiology of inflammation. This study is aimed at evaluating the potential association of V279F and A379V in PLA2G7 gene with ischemic stroke where inflammatory process is involved. DESIGN AND METHODS: A total of 386 patients with ischemic stroke and 386 healthy controls were included in the study. The single nucleotide polymorphisms, V279F and A379V, were analyzed by the polymerase chain reaction-ligation detection reaction method. RESULTS: The frequencies of VV+AV genotype, AV genotype and V allele of A379V in the patients with ischemic stroke were significantly higher than those in the controls (P=0.02, P=0.03, P=0.02, respectively). These correlations still remained after adjusting for confounding risk factors of stroke. Furthermore, subgroup analysis showed that a significant association with A379V was found in large-artery atherosclerotic stroke subgroup. In addition, no significant association was observed between V279F and ischemic stroke. CONCLUSION: The study indicated that the A379V variant in PLA2G7 gene might contribute to ischemic stroke susceptibility in northern Chinese Han population.