Collateral Flow in Magnetic Resonance Angiography: Prognostic Value for Vertebrobasilar Stenosis With Stroke Recurrence

Background and PurposeIntracranial vertebrobasilar atherosclerotic stenosis (IVBAS) is a major cause of posterior circulation stroke. Some patients suffer from stroke recurrence despite receiving medical treatment. This study aimed to determine the prognostic value of a new score for the posterior communicating artery and the P1 segment of the posterior cerebral artery (PCoA-P1) for predicting stroke recurrence in IVBAS.MethodsWe retrospectively enrolled patients with severe IVBAS (70%–99%). According to the number of stroke recurrences, patients were divided into no-recurrence, single-recurrence, and multiple-recurrences groups. We developed a new 5-point grading scale, with the PCoA-P1 score ranging from 0 to 4 based on magnetic resonance angiography, in which primary collaterals were dichotomized into good (2–4 points) and poor (0 or 1 point). Stroke recurrences after the index stroke were recorded. Patients who did not experience stroke recurrence were compared with those who experienced single or multiple stroke recurrences.ResultsFrom January 2012 to December 2019, 176 patients were enrolled, of which 116 (65.9%) had no stroke recurrence, 35 (19.9%) had a single stroke recurrence, and 25 (14.2%) had multiple stroke recurrences. Patients with single stroke recurrence (odds ratio [OR]=4.134, 95% confidence interval [CI]=1.822–9.380, p=0.001) and multiple stroke recurrences (OR=6.894, 95% CI=2.489–19.092, p<0.001) were more likely to have poor primary collaterals than those with no stroke recurrence.ConclusionsThe new PCoA-P1 score appears to provide improve predictions of stroke recurrence in patients with IVBAS.     

Long‐term outcome of cerebral amyloid angiopathy‐related hemorrhage

ObjectThe long‐term functional outcome of cerebral amyloid angiopathy‐related hemorrhage (CAAH) patients is unclear. We sought to assess the long‐term functional outcome of CAAH and determine the prognostic factors associated with unfavorable outcomes.MethodsWe enrolled consecutive CAAH patients from 2014 to 2020 in this observational study. Baseline characteristics and clinical outcomes were presented. Multivariable logistic regression analysis was performed to identify the prognostic factors associated with long‐term outcome.ResultsAmong the 141 CAAH patients, 76 (53.9%) achieved favorable outcomes and 28 (19.9%) of them died at 1‐year follow‐up. For the longer‐term follow‐up with a median observation time of 19.0 (interquartile range, 12.0–26.5) months, 71 (50.4%) patients obtained favorable outcomes while 33 (23.4%) died. GCS on admission (OR, 0.109; 95% CI, 0.021–0.556; p = 0.008), recurrence of ICH (OR, 2923.687; 95% CI, 6.282–1360730.14; p = 0.011), WML grade 3–4 (OR, 31.007; 95% CI, 1.041–923.573; p = 0.047), severe central atrophy (OR, 4220.303; 95% CI, 9.135–1949674.84; p = 0.008) assessed by CT was identified as independent predictors for long‐term outcome.InterpretationNearly 50% of CAAH patients achieved favorable outcomes at long‐term follow‐up. GCS, recurrence of ICH, WML grade and cerebral atrophy were identified as independent prognostic factors of long‐term outcome.     

Brain Metabolic Network Redistribution in Patients with White Matter Hyperintensities on MRI Analyzed with an Individualized Index Derived from 18F-FDG-PET/MRI

ObjectiveWhether metabolic redistribution occurs in patients with white matter hyperintensities (WMHs) on magnetic resonance imaging (MRI) is unknown. This study aimed 1) to propose a measure of the brain metabolic network for an individual patient and preliminarily apply it to identify impaired metabolic networks in patients with WMHs, and 2) to explore the clinical and imaging features of metabolic redistribution in patients with WMHs.Materials and MethodsThis study included 50 patients with WMHs and 70 healthy controls (HCs) who underwent ¹⁸F-fluorodeoxyglucose-positron emission tomography/MRI. Various global property parameters according to graph theory and an individual parameter of brain metabolic network called “individual contribution index” were obtained. Parameter values were compared between the WMH and HC groups. The performance of the parameters in discriminating between the two groups was assessed using the area under the receiver operating characteristic curve (AUC). The correlation between the individual contribution index and Fazekas score was assessed, and the interaction between age and individual contribution index was determined. A generalized linear model was fitted with the individual contribution index as the dependent variable and the mean standardized uptake value (SUV_mean) of nodes in the whole-brain network or seven classic functional networks as independent variables to determine their association.ResultsThe means ± standard deviations of the individual contribution index were (0.697 ± 10.9) × 10^-3 and (0.0967 ± 0.0545) × 10^-3 in the WMH and HC groups, respectively (p < 0.001). The AUC of the individual contribution index was 0.864 (95% confidence interval, 0.785–0.943). A positive correlation was identified between the individual contribution index and the Fazekas scores in patients with WMHs (r = 0.57, p < 0.001). Age and individual contribution index demonstrated a significant interaction effect on the Fazekas score. A significant direct association was observed between the individual contribution index and the SUV_mean of the limbic network (p < 0.001).ConclusionThe individual contribution index may demonstrate the redistribution of the brain metabolic network in patients with WMHs.     

婴幼儿泄殖腔畸形一例

患儿女,6个月。以"腹胀,无大便2 d"为主诉,以"肠梗阻"为诊断入院。入院后肛诊时直肠前触及质软肿物,挤压肿物时发现阴道后壁有一瘘口,自瘘口排出较多成形大便,肠梗阻缓解。追问病史,患儿生后3 d时曾因"先天性无肛会阴瘘"行会阴肛门成形术,术时发现双阴道畸形,在阴道纵隔下端发现一瘘口,有大便排出,未行处理。入院后体检明确双阴道畸形,在阴道纵隔下端发现一瘘口(图1)。术前检查:瘘管造影提示结肠重复畸形,MRI检查提示为全结肠重复畸形(图2),脊柱正常。B型超声:①结肠呈双管状结构;②左侧输尿管口囊肿,肾盂无分离;③子宫有纵行隔膜,未见子宫积液。同位素核素扫描未见结肠核素异常聚集。入院诊断:①先天性无肛会阴瘘(术后);②全结肠重复畸形;③左侧输尿管囊肿;④双阴道、双子宫畸形。术前讨论及准备后行腹腔镜辅助手术。术中见子宫呈"蝶状",子宫底部有分离(图3)。     

基于中医传承辅助平台分析高血压病阴阳两虚证的用药规律

目的分析治疗高血压病阴阳两虚证的方药特征信息,探索组方用药规律,挖掘有效的药物组合及新处方。方法检索相关数据库并查阅资料,收集关于高血压病阴阳两虚证的文献和医案,筛选治疗该病证的方剂。基于中医传承辅助平台(V 2. 5)建立方药特征数据库,并通过关联规则分析法、改进互信息法、熵层次聚类等方法,对处方用药进行数据分析。结果筛选出关于高血压病阴阳两虚证的组方179首,中药190味,使用频次最高的三味中药为熟地黄、茯苓、山药,并获得核心药物组合24个,新处方12个。结论通过此研究,明确了本病的用药规律,得出滋阴助阳、补益肾气为治疗高血压病阴阳两虚证的主要方法,对本病的临床治疗及组方用药具有重要价值。     

Association between thyroid hormone levels and frailty in the community-dwelling oldest-old: a cross-sectional study

Background:Changes in thyroid hormone levels are commonly recognized characters among the elderly, which were reported to potentially influence incident frailty. Therefore, we examined the cross-sectional associations of thyroid hormones (THs) with frailty as well as the five components characterizing frailty (fatigue, resistance, ambulation, number of illnesses, and loss of weight) among the oldest-old.Methods:Four hundred and eighty-seven community-dwelling oldest-old from a local community in Haidian District, Beijing, participated in our recruitment campaign between April 2019 and May 2020. The primary outcomes were a definitive diagnosis of frailty according to the FRAIL scale (Fatigue, Resistance, Ambulation, Illnesses, Loss of weight) and a positive score for each frailty subdomain. Demographic information (age, sex, marital status, and educational status), comorbidities, and details on the participants’ lifestyles were recorded. Serum THs including free triiodothyronin (fT3), triiodothyronine (T3), free thyroxine (fT4), and thyroxine (T4) and thyroid stimulating hormone (TSH) levels were also measured at the beginning of our study. Logistic regressions were conducted to screen for potential risk factors for frailty and its subdomains.Results:Among the total 487 subjects at enrollment, 60 (12.23%) of them were diagnosed with subclinical hypothyroidism and 110 (22.59%) of the total population scored positive for frailty. Logistic regression analyses adjusted for all potential confounders, showed that frailty was significantly associated with the serum TSH concentration (odds ratio [OR]: 1.06), fT3 concentration (OR: 0.54), and subclinical hypothyroidism score (OR: 2.18). The association between fT4 and frailty was absent in our observational study. The fT3/fT4 ratio characterizing peripheral hormone conversion was also tested to be correlated with frailty.Conclusion:Subclinical hypothyroidism, higher TSH level, lower fT3 level, and decreased fT3/fT4 ratio were all associated with frailty assessed by the FRAIL scale among the community-dwelling oldest-old, suggesting a relevant role of thyroid function in aging. Future longitudinal studies are warranted to determine the casual relationship between thyroid dysfunction and frailty in the oldest-old.     

A theoretical study based on DFT calculations on the different influence of functional groups on the C–H activation process via Pd-catalysed β-X elimination

We have performed a series of theoretical calculations for palladium-catalyzed β-X elimination reactions. The DFT calculation combined with energy decomposition analysis shows the determining factors of reactivity. Such as, the elemental composition, the structure of different functional groups and the stronger steric repulsions contribution.

The energy decomposition analysis (EDA) results show the quantitative contribution of nucleophile groups in intramolecular interactions.     

Molecular dynamics simulation study of adsorption of anionic–nonionic surfactants at oil/water interfaces

Four anionic–nonionic surfactants with the same headgroups and different units of oxygen ethyl (EO) and oxygen propyl (PO) were adopted to investigate the influence on oil/water interfacial tensions in this article. Molecular dynamics (MD) simulations were conducted to study the interfacial property of the four surfactants. Four parameters were proposed to reveal the effecting mechanism of molecular structure on interfacial tension, which included the interfacial thickness, order parameter of the hydrophobic chain, radial distribution function, and the solvent accessible surface area. In addition, the electrostatic potential of the four surfactants was calculated. The research results indicated that the interface facial mask formed by the surfactants, which contained three EO or three PO units was more stable, and it was easier for the surfactants of six EO or six PO units to form a microemulsion at higher concentrations. The adsorption mechanism of the anionic–nonionic surfactant systems at the oil/water interfaces was supplemented at a molecular level, which provided fundamental guidance for an in-depth understanding of the optimal selection of the surfactants in enhancing oil recovery.

Four anionic–nonionic surfactants with the same headgroups and different units of oxygen ethyl (EO) and oxygen propyl (PO) were adopted to investigate the influence on oil/water interfacial tensions in this article.     

Core-shell structured Co3O4@PPy composite for electrochemical determination of terbutylhydroquinone

TBHQ is a significant synthetic antioxidant, but excessive use of TBHQ is harmful to human health. Therefore, the preparation of a high-efficiency TBHQ electrochemical sensor is of great significance. In this work, a core–shell structured Co₃O₄@PPy composite is synthesized for TBHQ determination and exhibits remarkable electrochemical properties. The core–shell structure of Co₃O₄@PPy composite shows the synergistic effects of fast charge transfer, rich active surface area and more active sites. Under optimal conditions, the linear range of the developed sensor is 0.2–600 μM, and the detection limit is 0.05 μM (S/N = 3). In addition, it also has good stability and reproducibility due to the stable protective role of the PPy shell. The proposed sensor can also be applied to practical sample detection.

TBHQ is a significant synthetic antioxidant, but excessive use of TBHQ is harmful to human health.