Synthesis Of Open-Shell Iron Oxide-Polyelectrolyte-Silica Nanocomposite For Water Treatment Application

A open shell structure of silica-polyelectrolyte-iron oxide nanocomposite is synthesized via layer-by-layer assembly. Here, silica colloid is synthesized by Stöber process and iron oxide nanoparticles (IONPs) is synthesized by co-precipitation method. The successful assembly of silica, polyelectrolyte and IONPs into unified nanocomposite was monitored with dynamic light scattering (DLS) and electrophoretic mobility. The core-shell morphology of the nanocomposite was confirmed under the examination of Transmission Electron Microscope (TEM). The final structure showed good colloidal stability up to 10 hours under the monitoring of DLS. The nanocomposite was more magnetically responsive than the bare IONPs with shorten collection time after their exposure to low magnetic field gradient. The interfacial phenomena, which is the conformation of the particles-polymeric structure was monitored by Quartz Crystal Microbalance with Dissipation (QCM-D). The loosely bound and flexible nature of polyelectrolyte promoted larger IONPs deposited amount compared to the bare silica surface without a pre-adsorbed polyelectrolyte. Increasing the initial IONPs concentration (20 to 500 ppm) suppressed the polyelectrolyte layer, giving rise to a stiffer particles-polymeric structure. By increasing the solution ionic strength (0.1 to 100 mM) within critical coagulation concentration up to 50 mM NaCl (obtained by DLS and Derjaguin-Landau-Verwey-Overbeek theory), the particles-polymeric structure became more flexible, leading to the greater amount of deposited IONPs. The open shell structure of the nanocomposite was varied with different polyelectrolyte hierarchy, nature and architecture. From DLS, QCM-D, TEM and AFM (Atomic Force Microscope), it was observed that the deposition of greater amount of IONPs and pollutants molecules into polymeric network was attributed by: (1) the flexible structure conserved by the single layer rather than multilayers of polyelectrolyte, (2) the more extended structure constructed by higher molecular weight than the lower molecular weight of polyelectrolyte, and (3) the branched chain compared to linear chain of polyelectrolyte. Mean field and scaling approximations showed that the protruding side chains of branched PEI contributed to the thicker adsorbed layer (16.14 nm) with more ramified structure compared to linear PDDA (0.19 nm). By taking cationic Methylene Blue, anionic Methyl Orange dyes and Amoxicillin antibiotic as the model system, the performance of nanocomposite can be compared with the silica, silica-polyelectrolyte and bare IONPs. With the ability to facilitate Fenton and Fenton-like reaction with the presence of hydrogen peroxide, nanocomposite achieved highest pollutant removal efficiency among the synthesized nanoparticles. The easiness of magnetic recollection enabled nanocomposite to be recycled for subsequent pollutant removal runs. Nanocomposite retained high pollutant removal efficiency for total 5 recycled runs without significant dissolution of the IONPs from the nanocomposite. The pollutant removal process by nanocomposite can be well illustrated using Langmuir isotherm and pseudo-second-order kinetic model

Metabolism of Salvianolic Acid A and Antioxidant Activities of Its Methylated Metabolites

ABSTRACT This study investigated the metabolism of salvianolic acid A (SAA) both in vivo and in vitro. Liquid chromatography-mass spectrometry analysis of drug-containing rat bile samples and bile samples hydrolyzed by glucuronidase revealed a series of methylated conjugates of SAA and its glucuronides, as well as the predominance of the methylation pathway of SAA in rats. For the first time, four major methylated metabolites present in vivo were prepared for structure characterization and bioactivity evaluation using in vitro coincubation systems with rat hepatic cytosol protein as the enzyme donor. By using nuclear magnetic resonance imaging and other spectroscopic methods, these metabolites were unambiguously elucidated as 3-O-methyl-SAA (M1), 39-O-methyl-SAA (M2), 3,30-O-dimethyl-SAA (M3), and 39,30-O-dimethyl-SAA (M4), respectively. Along with results from the enzyme inhibition study, selective formation of these meta-O-methylated derivatives indicated that catechol O-methyltransferase (COMT) is responsible for methylated transformation of SAA. All of these metabolites displayed fairly high antioxidant potency against in vitro rat liver lipid peroxidation with halfmaximal inhibitory concentrations that were much lower than those of the positive controls and even SAA. Overall, the results from this study demonstrate that SAA is a metabolically unstable compound that undergoes rapid methylation metabolism catalyzed by COMT, and these generated O-methylated metabolites may be largely responsible for its in vivo pharmacological effects

Human papillomavirus 16 infection predicts poor outcome in patients with esophageal squamous cell carcinoma

BACKGROUND: Previous studies indicate that human papillomavirus 16 (HPV16) infection plays a pivotal role in the etiology of esophageal squamous cell carcinoma (ESCC). We aim to detect the influence of HPV16 infection on ESCC patient prognosis. PATIENTS AND METHODS: Immunohistochemical staining for HPV16 E6 oncoprotein, the low-affinity p75 neurotrophin receptor (p75NTR), and phosphatidylinositol 3-kinase (PI3K) was performed on 103 archived surgical specimens from patients with ESCC and 54 control samples from patients with benign esophageal tumor or inflammatory lesions. All patients were from the Shaan Xi Province, People’s Republic of China. RESULTS: HPV16 E6 expression was significantly higher in the ESCC group (P<0.05). HPV16 E6 expression was significantly higher in men than in women (P<0.05). p75NTR expression was higher in those aged >56 years (P<0.05). PI3K expression was higher in those with a more advanced histopathological grade (P<0.05). There was a positive correlation between HPV16 E6 and p75NTR expression (r=0.547, P<0.001) and between p75NTR and PI3K expression (r=0.364, P<0.001). In 100 evaluable patients, the 5-year overall survival (OS) rate was 11%. In patients with ESCC, HPV16 E6 and PI3K expression were negatively correlated with the 3-year OS (P<0.05), 5-year OS (P<0.05), and progression-free survival (P<0.05). CONCLUSION: HPV16 infection likely contributes to the etiology of ESCC patients in Shaan Xi, People’s Republic of China. HPV16 infection status and PI3K expression levels could be useful for predicting prognosis in patients with ESCC

Diffusion Tensor Imaging With Tract-Based Spatial Statistics Reveals White Matter Abnormalities in Patients With Vascular Cognitive Impairment

Purpose: The aim of this study was to evaluate microstructural changes of major white matter (WM) tracts in patients with vascular cognitive impairment (VCI).Method: Diffusion tensor imaging (DTI) data were obtained from 24 subjects with subcortical ischemic vascular disease (SIVD), including 13 subjects with VCI-no dementia (VCIND) and 11 subjects with normal cognition (as a control group). A tract-based spatial statistics approach was performed to investigate WM microstructure in VCIND by integrating multiple indices including fractional anisotropy (FA) and mean diffusivity (MD), which are intra-voxel metrics, and local diffusion homogeneity (LDH), which is an inter-voxel metric.Results: The VCIND group had decreased FA and increased MD values throughout widespread WM areas predominately in the corpus callosum, bilateral internal capsule/corona radiata/posterior thalamic radiation/inferior fronto-occipital fasciculus and right inferior/superior longitudinal fasciculus. There was a slight discrepancy between the distribution of areas with decreased FA and LDH. The FA, MD and LDH values were significantly correlated with cognitive test results. According to a WM tract atlas, 10 major tracts were identified as tracts of interest in which three diffusion metrics simultaneously differed between groups, including bilateral anterior thalamic radiation, forceps minor, right corticospinal tract, bilateral inferior fronto-occipital fasciculus, left inferior and superior longitudinal fasciculus, and bilateral uncinate fasciculus. Receiver operating characteristic (ROC) analysis demonstrated the feasibility of using diffusion metrics along the forceps minor and left anterior thalamic radiation for separating two groups.Conclusion: The results suggest WM microstructural abnormalities contribute to cognitive impairments in SIVD patients. DTI parameters may be potential biomarkers for detecting VCIND from SIVD

mNGS helped diagnose scrub typhus-associated HLH in children: a report of two cases

BackgroundScrub typhus, caused by the Orientia tsutsugamushi (Ot), is a widespread vector-borne disease transmitted by chigger mites. Hemophagocytic lymphohistiocytosis (HLH) is considered to be one of the potentially severe complications. The diagnosis of scrub typhus-associated HLH may be overlooked due to the non-specific clinical characteristics and the absence of pathognomonic eschar.Case presentationWe obtained clinical data from two patients in the South of Sichuan, China. The first case involved a 6-year-old girl who exhibited an unexplained fever and was initially diagnosed with sepsis, HLH, and pulmonary infection. The other patient presented a more severe condition characterized by multiple organ dysfunction and was initially diagnosed with septic shock, sepsis, HLH, acute kidney injury (AKI), and pulmonary infection. At first, a specific examination for scrub typhus was not performed due to the absence of a characteristic eschar. Conventional peripheral blood cultures yielded negative results in both patients, and neither of them responded to routine antibiotics. Fortunately, the causative pathogen Orientia tsutsugamushi (Ot) was detected in the plasma samples of both patients using metagenomics next-generation sequencing (mNGS) and further confirmed by polymerase chain reaction. Subsequently, they both were treated with doxycycline and recovered quickly.ConclusionThe unbiased mNGS provided a clinically actionable diagnosis for an uncommon pathogen-associated infectious disease that had previously evaded conventional diagnostic approaches

MicroRNA-9 induces defective trafficking of Nav1.1 and Nav1.2 by targeting Navβ2 protein coding region in rat with chronic brain hypoperfusion

BACKGROUND: Previous studies have demonstrated that the trafficking defects of Nav1.1/Nav1.2 are involved in the dementia pathophysiology. However, the detailed mechanisms are not fully understood. Moreover, whether the impaired miRNAs regulation linked to dementia is a key player in sodium channel trafficking disturbance remains unclear. The cognitive impairment induced by chronic cerebral ischemia through chronic brain hypoperfusion (CBH) is likely reason to precede dementia. Therefore, our goal in the present study was to examine the role of microRNA-9 (miR-9) in regulating Nav1.1/Nav1.2 trafficking under CBH generated by bilateral common carotid artery occlusion (2VO). RESULTS: The impairment of Nav1.1/Nav1.2 trafficking and decreased expression of Navβ2 were found in the hippocampi and cortices of rats following CBH generated by bilateral 2VO. MiR-9 was increased in both the hippocampi and cortices of rats following CBH by qRT-PCR. Intriguingly, miR-9 suppressed, while AMO-miR-9 enhanced, the trafficking of Nav1.1/Nav1.2 from cytoplasm to cell membrane. Further study showed that overexpression of miR-9 inhibited the Navβ2 expression by targeting on its coding sequence (CDS) domain by dual luciferase assay. However, binding-site mutation or miR-masks failed to influence Navβ2 expression as well as Nav1.1/Nav1.2 trafficking process, indicating that Navβ2 is a potential target for miR-9. Lentivirus-mediated miR-9 overexpression also inhibited Navβ2 expression and elicited translocation deficits to cell membrane of Nav1.1/Nav1.2 in rats, whereas injection of lentivirus-mediated miR-9 knockdown could reverse the impaired trafficking of Nav1.1/Nav1.2 triggered by 2VO. CONCLUSIONS: We conclude that miR-9 may play a key role in regulating the process of Nav1.1/Nav1.2 trafficking via targeting on Navβ2 protein in 2VO rats at post-transcriptional level, and inhibition of miR-9 may be a potentially valuable approach to prevent Nav1.1/Nav1.2 trafficking disturbance induced by CBH

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe