130 research outputs found
Facile synthesis of graphene via direct water-sodium dodecylbenzenesulfonate exfoliation
In this study, a mild, one-step electrochemical exfoliation was demonstrated for the synthesis of graphene with the assistance of water and a surfactant, particularly sodium dodecylbenzenesulfonate and sodium dodecyl sulphate. Different types of water-surfactant solutions in different concentrations could influence the exfoliation of graphite rods. From one to several layers of graphene flakes (with a thickness of approximately 1 nm) could be produced directly after sonication. AFM images showed that the flake diameters from this source were typically small. Raman and IR spectroscopic analyses of the dispersed phase suggested that the exfoliation of graphene sheets was accomplished. The flakes were also characterized using field emission scanning electron microscopy, X-ray diffraction, and cyclic voltammetry techniques. Further improvements in this methodology may pave the way to develop green, cost-effective, and large-scale production methods for graphene sheets
Retained stone retrieval basket causing chronic pancreatitis: a case report
BackgroundEndoscopic retrograde cholangiopancreatography is a common procedure performed for choledocholithiasis and gallstone pancreatitis. Although a relatively low risk procedure, it is not without its complications. Cases of impacted Dormia baskets during stone retrieval have been reported, but these are usually retrieved surgically during the same setting.Case summaryA 40-year-old man presented to our hospital with an episode of epigastric pain and discomfort. He has a prior background of recurrent episodes of pancreatitis of which he underwent prior endoscopic therapy in his home country. Initial investigations revealed a metallic object seen on abdominal x-ray, computer tomographic scan of the abdomen and pelvis, and magnetic resonance imaging of the pancreas. Further evaluation was done with endoscopy, which revealed a retained stone extraction basket from a previous endoscopic retrograde pancreatography, resulting in recurrent episodes of acute chronic pancreatitis. Although the retained foreign body was removed, he subsequently developed further complications of portal vein thrombosis as a result of recurrent acute chronic pancreatitis, which required anticoagulation.ConclusionThis case highlights the importance of retrieving any foreign body from the pancreas, especially on the head, to prevent the development of further complications
The atypical chemokine receptor Ackr2 constrains NK cell migratory activity and promotes metastasis
Chemokines have been shown to be essential players in a range of cancer contexts. In this study, we demonstrate that mice deficient in the atypical chemokine receptor Ackr2 display impaired development of metastasis in vivo in both cell line and spontaneous models. Further analysis reveals that this relates to increased expression of the chemokine receptor CCR2, specifically by KLRG1+ NK cells from the Ackr2−/− mice. This leads to increased recruitment of KLRG1+ NK cells to CCL2-expressing tumors and enhanced tumor killing. Together, these data indicate that Ackr2 limits the expression of CCR2 on NK cells and restricts their tumoricidal activity. Our data have important implications for our understanding of the roles for chemokines in the metastatic process and highlight Ackr2 and CCR2 as potentially manipulable therapeutic targets in metastasis
Placental chemokine compartmentalisation: a novel mammalian molecular control mechanism
Atypical chemokine receptor 2 (ACKR2) is a chemokine-scavenging receptor. ACKR2–/–embryos display a reduction in size of a novel, to our knowledge, embryonic skin macrophage population referred to as ‘intermediate’ cells. CC chemokine receptor 2 (CCR2)–/–embryos display an identical phenotype, indicating that these cells require CCR2 to enable them to populate embryonic skin. Further analysis revealed that ACKR2–/–embryos have higher circulating concentrations of the CCR2 ligand, CC ligand 2 (CCL2); thus, ACKR2 regulates intraembryonic CCL2 levels. We show that ACKR2 is strongly expressed by trophoblasts and that it blocks movement of inflammatory chemokines, such as CCL2, from the maternal decidua into the embryonic circulation. We propose that trophoblastic ACKR2 is responsible for ensuring chemokine compartmentalisation on the maternal decidua, without which chemokines enter the embryonic circulation, disrupting gradients essential for directed intraembryonic cell migration. Overall, therefore, we describe a novel, to our knowledge, molecular mechanism whereby maternal decidual chemokines can function in a compartmentalised fashion without interfering with intraembryonic leukocyte migration. These data suggest similar functions for other atypical chemokine receptors in the placenta and indicate that defects in such receptors may have unanticipated developmental consequences
What Drives Animal Fluency Performance in Cantonese-Speaking Chinese Patients with Adult-Onset Psychosis?
Among the numerous studies investigating semantic factors associated with functioning in psychotic patients, most have been conducted on western populations. By contrast, the current cross-sectional study involved native Cantonese-speaking Chinese participants. Using the category fluency task, we compared performance between patients and healthy participants and examined clinical and sociodemographic correlates. First-episode psychosis patients (n = 356) and gender- and age-matched healthy participants (n = 35) were asked to generate as many ‘animals’ as they could in a minute. As expected, patients generated fewer correct responses (an average of 15.5 vs. 22.9 words), generated fewer clusters (an average of 3.7 vs. 5.4 thematically grouped nouns), switched less between clusters (on average 8.0 vs. 11.9 switches) and, interestingly, produced a larger percentage of Chinese zodiac animals than healthy participants (an average of 37.7 vs. 24.2). However, these significant group differences in the clusters and switches disappeared when the overall word production was controlled for. Within patients, education was the strongest predictor of category fluency performance (namely the number of correct responses, clusters, and switches). The findings suggest that an overall slowness in patients may account for the group differences in category fluency performance rather than any specific abnormality per se
Elevated expression of the chemokine-scavenging receptor D6 is associated with impaired lesion development in psoriasis
D6 is a scavenging-receptor for inflammatory CC chemokines that are essential for resolution of inflammatory responses in mice. Here, we demonstrate that D6 plays a central role in controlling cutaneous inflammation, and that D6 deficiency is associated with development of a psoriasis-like pathology in response to varied inflammatory stimuli in mice. Examination of D6 expression in human psoriatic skin revealed markedly elevated expression in both the epidermis and lymphatic endothelium in "uninvolved" psoriatic skin (ie, skin that was more than 8 cm distant from psoriatic plaques). Notably, this increased D6 expression is associated with elevated inflammatory chemokine expression, but an absence of plaque development, in uninvolved skin. Along with our previous observations of the ability of epidermally expressed transgenic D6 to impair cutaneous inflammatory responses, our data support a role for elevated D6 levels in suppressing inflammatory chemokine action and lesion development in uninvolved psoriatic skin. D6 expression consistently dropped in perilesional and lesional skin, coincident with development of psoriatic plaques. D6 expression in uninvolved skin also was reduced after trauma, indicative of a role for trauma-mediated reduction in D6 expression in triggering lesion development. Importantly, D6 is also elevated in peripheral blood leukocytes in psoriatic patients, indicating that upregulation may be a general protective response to inflammation. Together our data demonstrate a novel role for D6 as a regulator of the transition from uninvolved to lesional skin in psoriasis
Recommended from our members
Early intervention for incipient insanity: early notions from the 19th century English literature.
AIM: Early intervention programmes in mental illnesses started to bloom in the 1990s, and many programmes have been established worldwide during the past twenty years. However, the concept of early intervention has emerged during the 19th century but it did not make much impact on practice. The aim of this review is to identify the difficulties appeared during that period of time which could provide insight into the modern development of early intervention initiatives. METHODS: A narrative review which focused on English literature about early intervention for insanity during the 19th century was undertaken. RESULTS: Clinicians during the 19th century recognized that treatment would be the most effective at the early stage of the mental illness and they had emphasized the importance of early intervention. However, because of a number of factors, such as the limited roles of asylums, lack of knowledge about mental disorder and the lack of effective treatment, the idea of early intervention did not make impact in clinical service during that period of time. CONCLUSION: During the past two hundred years, understanding towards mental illness has advanced and more effective treatments, such as the use of anti-psychotic medications, have been developed. Reflecting on the past experience and difficulties might shed light on the development of today early intervention in mental disorder.This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by Wiley
Sustainability of treatment effect of a 3-year early intervention programme for first-episode psychosis
Estimating Infection Attack Rates and Severity in Real Time during an Influenza Pandemic: Analysis of Serial Cross-Sectional Serologic Surveillance Data
This study reports that using serological data coupled with clinical surveillance data can provide real-time estimates of the infection attack rates and severity in an emerging influenza pandemic
- …