Simultaneous enrichment and speciation of lead and mercury by magnetic solid-phase extraction coupled to HPLC-ICP-MS based on magnetic hydrazine-linked covalent organic frameworks.

BACKGROUND: Trace levels of organic and inorganic lead and mercury species in the environment, including divalent lead (Pb2+), trimethyllead (TML), divalent mercury (Hg2+), monomethylmercury (MeHg), and ethylmercury (EtHg), are highly toxic to humans and ecology. It is of great importance for speciation of lead and mercury to evaluate the toxicity of lead and mercury and their biogeochemistry in the environment. However, simultaneous multi-elemental enrichment and speciation at trace level remains a challenge. There are few reports of simultaneous magnetic solid-phase extraction (MSPE) of organic and inorganic lead and mercury species at trace level in the real water. RESULTS: In this work, a novel core-shell magnetic hydrazine-linked covalent organic frameworks (Fe3O4@COF-TCH) was prepared for the first time by grafting hydrazine-linked COFs on the Fe3O4 nanoparticles. Fe3O4@COF-TCH with abundant thione and imino groups has strong adsorption for lead and mercury species. Based on it, a simple and practical magnetic solid-phase extraction high-performance liquid chromatography-inductively coupled plasma mass spectrometry (MSPE-HPLC-ICP-MS) method was developed for extraction and determination of trace lead and mercury species, including Hg2+, MeHg, EtHg, Pb2+ and TML. The limits of detection (3δ) of the developed method were 0.08, 0.81, 0.90, 0.56 and 0.88 ng L-1 with the enrichment factors (EFs) of 384, 376, 379, 389 and 360-fold for Pb2+, TML, Hg2+, MeHg and EtHg, respectively. The high accuracy and reproducibility have been proved by the spiked recoveries (94.4-103 %) in real samples. SIGNIFICANCE: The proposed method with simple operation and high sensitivity has been successfully applied to simultaneous speciation of lead and mercury at trace levels in the water samples with complicated matrices, including underground water, surface water, sea water. Meanwhile, it has the advantages of cost-saving, labor-saving and time-saving and is suitable for the investigation and risk assessment in water. The development of MSPE-HPLC-ICP-MS method provides ideas and guidance for the simultaneous multi-elemental enrichment and speciation.

The relationship between symptomatic status and aneurysm wall enhancement characteristics of single unruptured intracranial aneurysm.

OBJECTIVE: We aimed to analyze the aneurysm wall enhancement (AWE) characteristics of a single unruptured intracranial aneurysm (UIA) and observe the relationship between the symptoms of a single UIA and the aneurysm wall. METHODS: In our hospital, 85 patients diagnosed with a single UIA using computed tomography angiography (CTA) were retrospectively analyzed. The patients were divided into symptomatic and asymptomatic groups, including 46 asymptomatic and 39 symptomatic aneurysms. High-resolution magnetic resonance imaging of the vascular wall (HR-MR-VWI) was utilized to ascertain the presence, degree, and extent of AWE and thick-wall enhancement. In addition to AWE characteristics, morphological parameters of aneurysms, such as maximal size, shape, height, neck width, aspect ratio (AR), and size ratio (SR), were scanned using CTA. The differences in the parameters of a single UIA between the two groups were compared. An investigation explored the correlation between the symptom status of a single UIA and AWE. RESULTS: We observed a correlation between symptom status and maximal size, height, and neck width for a single UIA, the presence or absence of AWE, and the levels and boundaries of AWE and thick-wall reinforcement. This study found that the AWE range was independently correlated with symptom status in the multivariate regression analysis. CONCLUSION: A larger AWE range was an independent risk factor for the onset of symptoms in a single UIA.

A novel P/N/Si/Zn-containing hybrid flame retardant for enhancing flame retardancy and smoke suppression of epoxy resins.

Currently, additively efficient flame retardants are being developed to enhance the smoke suppression, flame retardancy, and thermal properties of composite materials. To this end, the current study designed and prepared a novel P/N/Si/Zn-containing organic-inorganic hybrid denoted as APHZ. Its inorganic part was 2-methylimidazole zinc salt (ZIF-8), which improved its smoke suppression and catalytic carbonization. The organic part (P/N/Si-containing compound) promoted its flame retardancy and interfacial compatibility between APHZ and epoxy resin (EP). The test results revealed that EP/APHZ-3 composites achieved a V-0 rating and a notable LOI value of 30.7% when introducing 3 wt% APHZ into the EP matrix. Cone calorimetry tests (CCT) further demonstrated that the average heat release rate (av-HRR), total smoke production (TSP), and CO production (COP) of EP/APHZ-3 were reduced by 23.3%, 14.0%, and 21.1%, respectively. Meanwhile, the char residual was increased by 60.6%, as compared to pure EP. Furthermore, the flame-retardant mechanism of EP/APHZ composites was investigated by the XPS, TG-FTIR, and Raman spectroscopy techniques. The observed synergistic effect of the imidazole skeleton ZIF-8 and P/N/Si-containing compound in APHZ facilitated the generation of a dense multi-element char layer, with the condensed phase flame-retardant mechanism playing a dominant role. These findings contribute to developing and designing high-performance flame-retardant EP.

Magnetic Resonance Imaging of Dural Sinus Malformation in a Fetus: A Case Report.

BACKGROUND: Dural sinus malformation (DSM) is a rather rare congenital condition that can be encountered in the fetus and infants. The cause and etiology of DSM remain unclear. Obstetric ultrasound plays a key role in screening fetal brain malformations, and MRI is frequently used as a complementary method to confirm the diagnosis and provide more details. OBJECTIVE: Here, we present a fetus with DSM by multiple imaging methods to help better understand the imaging characteristics of this malformation. CASE PRESENTATION: A 22-year-old primipara was referred to our hospital at 25 weeks of gestation following the detection of a fetal intracranial mass without any symptoms. A prenatal ultrasound performed in our hospital at 25 + 2 gestational weeks showed a large anechoic mass with liquid dark space, while no blood flow was detected. After the initial evaluation, this primipara received a prenatal MRI in our hospital. This examination at 25 + 5 gestational weeks delineated a fan-shaped mass in the torcular herophili, which was iso-to hyperintense on T1WI and hypointense on T2WI. At the lower part of this lesion, a quasi-circular hyperintense on T1WI and a signal slightly hyperintense on T2WI could be seen. Meanwhile, the adjacent brain parenchyma was compressed by the mass. CONCLUSION: We reviewed the current literature to obtain a better understanding of the mechanisms, imaging characteristics, and survival status of DSM. Although the primipara of the present study regretfully opted for elective termination of pregnancy, the reevaluation of DSM survival deserves more attention because of the better survival data from recent studies.

Rapid, easy and catalyst-free preparation of magnetic thiourea-based covalent organic frameworks at room temperature for enrichment and speciation of mercury with HPLC-ICP-MS.

The complex and cumbersome preparation of magnetic covalent organic frameworks (COFs) nanocomposites on a small scale limits their application. Herein, a rapid and easy route was employed for the preparation of magnetic thiourea-based COFs nanocomposites. COFs were coated on Fe3O4 nanoparticles at room temperature without a catalyst within approximately 30 min. This method is suitable for the large-scale preparation of magnetic adsorbent. Using the as-prepared magnetic adsorbent (Fe3O4@COF-TpTU), we developed a simple, efficient, and sensitive magnetic solid-phase extraction-high performance liquid chromatography-inductively coupled plasma-mass spectrometry (MSPE-HPLC-ICP-MS) for the enrichment and determination of mercury species, including Hg2+, methylmercury (MeHg), and ethylmercury (EtHg). The effects of the experimental parameters on the extraction efficiency, including solution pH, adsorption and desorption time, composition and volume of the elution solvent, salinity, coexisting ions, and dissolved organic matter, were comprehensively investigated. Under optimised conditions, the limits of detection in the developed method were 0.56, 0.34, and 0.47 ng L-1 with enrichment factors of 190, 195, and 180-fold for Hg2+, MeHg, and EtHg, respectively. The satisfactory spiked recoveries (97.0-103%) in real water samples and high consistency between the certified and determined values in a certified reference material demonstrate the high accuracy and reproducibility of the developed method. The as-proposed method with simple operation, high sensitivity, and excellent anti-matrix interference performance was successfully applied to the enrichment and determination of trace levels of mercury species in the natural samples with complicated matrices, such as underground water, surface water, seawater and biological samples.

Preparation of Naphthalene-Based Flame Retardant for High Fire Safety and Smoke Suppression of Epoxy Resin.

One of the current challenges in the development of flame retardants is the preparation of an environmentally friendly multi-element synergistic flame retardant to improve the flame retardancy, mechanical performance, and thermal performance of composites. This study synthesized an organic flame retardant (APH) using (3-aminopropyl) triethoxysilane (KH-550), 1,4-phthalaadehyde, 1,5-diaminonaphthalene, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) as raw materials, through the Kabachnik-Fields reaction. Adding APH to epoxy resin (EP) composites could greatly improve their flame retardancy. For instance, UL-94 with 4 wt% APH/EP reached the V-0 rating and had an LOI as high as 31.2%. Additionally, the peak heat release rate (PHRR), average heat release rate (AvHRR), total heat release (THR), and total smoke produced (TSP) of 4% APH/EP were 34.1%, 31.8%, 15.2%, and 38.4% lower than EP, respectively. The addition of APH improved the mechanical performance and thermal performance of the composites. After adding 1% APH, the impact strength increased by 15.0%, which was attributed to the good compatibility between APH and EP. The TG and DSC analyses revealed that the APH/EP composites that incorporated rigid naphthalene ring groups had higher glass transition temperatures (Tg) and a higher amount of char residue (C700). The pyrolysis products of APH/EP were systematically investigated, and the results revealed that flame retardancy of APH was realized by the condensed-phase mechanism. APH has good compatibility with EP, excellent thermal performance, enhanced mechanical performance and rational flame retardancy, and the combustion products of the as-prepared composites complied with the green and environmental protection standards which are also broadly applied in industry.

The effects of nurse-led family pulmonary rehabilitation intervention on quality of life and exercise capacity in rural patients with COPD.

AIM: To assess the effects of nurse-led family pulmonary rehabilitation intervention on quality of life and exercise capacity in rural patients with chronic obstructive pulmonary disease (COPD). DESIGN: A non-randomized clinical trial. METHODS: This study enrolled COPD patients at two hospitals from January 2019 to January 2020. The primary outcome was the quality of life. The secondary outcome was exercise capacity. RESULTS: Seventy-four rural COPD patients were enrolled, 38 in the comprehensive nursing group and 36 in the routine nursing group. After the intervention, the St. George's Respiratory Questionnaire (SGRQ) scores in the comprehensive nursing group were significantly lower than in the routine nursing group, especially in symptoms, activities and total scores. The SGRQ scores of the comprehensive nursing group were significantly lower than baseline, while the SGRQ scores of the routine nursing group were significantly higher than baseline. After the intervention, there was a significant difference in six-minute walking distance(6MWD) between the two groups.

Effect of Carbon Fiber Nanotubes Tracheotomy Under Swallowing Training Combined with Bronchoscopic Alveolar Lavage.

This study aimed to analyze the effect of carbon fiber nanotube tracheotomy (CFNT) under swallowing training (ST) combined with bronchofiberoscope alveolar lavage (BAL), so as to provide theoretical guidance for the clinical treatment of pulmonary infection. 40 patients with pulmonary infection were selected as the research objects, and the effects of ST combined with BAL were analyzed after CFNT. The patients were randomly divided into four groups: a control group (group A) and three observation groups (groups B, C, and D), with 10 cases in each group. Patients in group A received conventional treatment, patients in group B received conventional treatment + ST, patients in group C received conventional treatment + BAL, and patients in group D received conventional treatment + ST + BAL. The effect of ST + BAL was analyzed after CFNT. The results showed that compared with the group A, the number of lung infections and infection rates in groups C and D was reduced (P < 0.05); the use time and per capita cost of antibiotics in group A were much higher than those in the groups C and D (P < 0.05); and in group B and D, the number of successful extubation of tracheal catheters and the success rate were greatly increased (P < 0.05) and the average time of intubation was dramatically shortened (P < 0.05). The scores of the water swallow test (WST) in groups B and D were much lower than the score of group A (P < 0.05), and the scores for swallowing ability and swallowing dysfunction scores were much different from those of the group A (P < 0.05). In summary, after a CFNT, the lung infection and swallowing function of patients were effectively improved after ST + BAL.

Magnetic solid-phase extraction for speciation of mercury based on thiol and thioether-functionalized magnetic covalent organic frameworks nanocomposite synthesized at room temperature.

A simple and practical magnetic solid-phase extraction high-performance liquid chromatography-inductively coupled plasma mass spectrometry (MSPE-HPLC-ICP-MS) method for extraction and determination of trace mercury species, including inorganic mercury (IHg), monomethylmercury (MeHg) and ethylmercury (EtHg), was developed. The MSPE adsorbent, urchin-like thiol and thioether-functionalized magnetic covalent organic frameworks (Fe3O4@COF-S-SH), was synthesized by coating covalent organic frameworks (COFs) on the surface of Fe3O4 nanoparticles at room temperature and then easily grafting 1,2-Ethanedithiol on the COFs. The as-prepared Fe3O4@COF-S-SH has strong adsorption capacity for IHg, MeHg and EtHg, with excellent static adsorption capacity: 571, 559 and 564 mg g-1, respectively. The parameters influencing the extraction and enrichment had been optimized, including pH, adsorption and desorption time, composition and amount of the eluent, co-existing ions and dissolved organic materials etc. Under the optimized condition, the limit of detection (3δ) of the proposed method were 0.96, 0.17 and 0.47 ng L-1 for IHg, MeHg and EtHg, and the developed method has high actual enrichment factors of 370, 395, 365-fold for IHg, MeHg and EtHg based on 200 mL samples, respectively. The high accuracy and reproducibility has been proved by the spiked recoveries (96.0‒108 %) in real water samples and determination of the certified reference material. Both the adsorption and desorption process can be completed within 5 min. The proposed method with simple operation, short pre-concentration time and high sensitivity has been successfully applied to mercury speciation at trace levels in the samples with complicated matrices, including underground water, surface water, sea water and fish samples.

Co-occurrence patterns among prokaryotes across an age gradient in pit mud of Chinese strong-flavor liquor.

It is widely believed that the quality and characteristics of Chinese strong-flavor liquor (CSFL) are closely related to the age of the pit mud; CSFL produced from older pit mud tastes better. This study aimed to investigate the alteration and interaction of prokaryotic communities across an age gradient in pit mud. Prokaryotic microbes in different-aged pit mud (1, 6, and 10 years old) were analyzed by Illumina MiSeq sequencing of the 16S rRNA gene. Analysis of the 16S rRNA gene indicated that the prokaryotic community was significantly altered with pit mud age. There was a significant increase in the genera Methanosarcina, Methanobacterium, and Aminobacterium with increased age of pit mud, while the genus Lactobacillus showed a significant decreasing trend. Network analysis demonstrated that both synergetic co-occurrence and niche competition were dominated by 68 prokaryotic genera. These genera formed 10 hubs of co-occurrence patterns, mainly under the phyla Firmicutes, Euryarchaeota, and Bacteroidetes, playing important roles on ecosystem stability of the pit mud. Environmental variables (pH, NH4+, available P, available K, and Ca2+) correlated significantly with prokaryotic community assembly. The interaction of prokaryotic communities in the pit mud ecosystem and the relationship among prokaryotic communities and environmental factors contribute to the higher quality of the pit mud in older fermentation pits.

[Chemical Constituents from Oldenlandia diffusa].

Objective: To study the chemical constituents of water extracted fraction from Oldenlandia diffusa. Methods: The compounds were isolated and purified by column chromatography on macroporous resin,silica gel,MCI gel,Sephadex LH-20,ODS medium pressure liquid chromatography and RP-semi-preparative HPLC. The structures of compounds were elucidated on the basis of physicochemical and spectral analysis. Results: 16 compounds were isolated from the water extract of Oldenlandia diffusa,and their structures were identified as asperuloside( 1),deacetyl asperuloside( 2),geniposide( 3),10-dehydrogeniposide( 4),daphylloside( 5),diffusoside A( 6),diffusoside B( 7),coniferin( 8),scandoside methyl ester( 9),acetyl scandoside methyl ester( 10),deacetylasperulosidic acid methyl ester( 11),gardenoside( 12),galioside( 13),galioside 10-acetate( 14),loliolide( 15) and( +)-neo-olivil( 16),respectively. Conclusion: Compounds 3,8 and 14 ~ 16 are obtained from Oldenlandia diffusa for the first time.

[Epidemiologic study on hearing impairment and ear diseases in old people].

OBJECTIVE: To investigate the prevalence of hearing impairment and ear diseases in old people and provide scientific data for drawing up the prevention and treatment strategies. METHODS: Using the probability proportion to size (PPS) method, 1261 people over 60 years were investigated in 40 clusters in Jiangsu Province with the WHO protocol. RESULTS: The prevalence of hearing impairment was 58.1% (the standardized rate: 59.5% in the whole country, 60.9% in Jiangsu province). Degrees of hearing impairment were mild (33.1%), moderate (17.8%), severe (5.9%) and profound (1.3%). The prevalence of hearing disability was 25.0% (the standardized rate: 26.6% in the whole country, 28.1% in Jiangsu province). There were significant difference of the prevalence between male and female, as well as urban and rural, and different ages. The prevalence of the ear diseases was auricle malformation (0.2%), wax (1.7%), otitis externa (0.1%), fungi (0.5%), serous otitis media (1.2%), chronic suppurative otitis media (1.6%), dry perforation of tympanic membrance (2.3%). The causes of hearing impairment were ear diseases (2.9%), non-infectious condition (92.6%), genetic condition (0.3%) and undetermined causes (4.2%). Of which, 31.1% of persons needed hearing aids while 2.3% of persons needed medicine treatment, but 0.9% of persons needed non-urgent surgery and 1.0% of persons needed other treatment. CONCLUSIONS: The prevalence of hearing impairment and disability in the old rised obviously than the last investigation in 1987. It was a heavy burden for social development in China. The government and the whole society should take more concern about the problem. The scientific strategies of prevention and treatment were urgently needed and implemented.