213 research outputs found
Delocalized electron holes on oxygen in a battery cathode
Oxide ions in transition metal oxide cathodes can store charge at high voltage offering a route towards higher energy density batteries. However, upon charging these cathodes, the oxidized oxide ions condense to form molecular O2 trapped in the material. Consequently, the discharge voltage is much lower than charge, leading to undesirable voltage hysteresis. Here we capture the nature of the electron holes on O2− before O2 formation by exploiting the suppressed transition metal rearrangement in ribbon-ordered Na0.6[Li0.2Mn0.8]O2. We show that the electron holes formed are delocalized across the oxide ions coordinated to two Mn (O–Mn2) arranged in ribbons in the transition metal layers. Furthermore, we track these delocalized hole states as they gradually localize in the structure in the form of trapped molecular O2 over a period of days. Establishing the nature of hole states on oxide ions is important if truly reversible high-voltage O-redox cathodes are to be realized.</p
Inhibiting CSF1R alleviates cerebrovascular white matter disease and cognitive impairment
\ua9 2023 The Authors. GLIA published by Wiley Periodicals LLC. White matter abnormalities, related to poor cerebral perfusion, are a core feature of small vessel cerebrovascular disease, and critical determinants of vascular cognitive impairment and dementia. Despite this importance there is a lack of treatment options. Proliferation of microglia producing an expanded, reactive population and associated neuroinflammatory alterations have been implicated in the onset and progression of cerebrovascular white matter disease, in patients and in animal models, suggesting that targeting microglial proliferation may exert protection. Colony-stimulating factor-1 receptor (CSF1R) is a key regulator of microglial proliferation. We found that the expression of CSF1R/Csf1r and other markers indicative of increased microglial abundance are significantly elevated in damaged white matter in human cerebrovascular disease and in a clinically relevant mouse model of chronic cerebral hypoperfusion and vascular cognitive impairment. Using the mouse model, we investigated long-term pharmacological CSF1R inhibition, via GW2580, and demonstrated that the expansion of microglial numbers in chronic hypoperfused white matter is prevented. Transcriptomic analysis of hypoperfused white matter tissue showed enrichment of microglial and inflammatory gene sets, including phagocytic genes that were the predominant expression modules modified by CSF1R inhibition. Further, CSF1R inhibition attenuated hypoperfusion-induced white matter pathology and rescued spatial learning impairments and to a lesser extent cognitive flexibility. Overall, this work suggests that inhibition of CSF1R and microglial proliferation mediates protection against chronic cerebrovascular white matter pathology and cognitive deficits. Our study nominates CSF1R as a target for the treatment of vascular cognitive disorders with broader implications for treatment of other chronic white matter diseases
TNF-α-Induced VEGF and MMP-9 Expression Promotes Hemorrhagic Transformation in Pituitary Adenomas
Pituitary apoplexy is a clinical syndrome with unknown pathogenesis. Therefore, identifying the underlying mechanisms is of high clinical relevance. Tumor necrosis factor alpha (TNF-α) is a critical cytokine mediating various hemorrhagic events, but little is known about its involvement in pituitary apoplexy. Here we show that TNF-α may be an important regulator of hemorrhagic transformation in pituitary adenomas. In this study, sixty surgical specimens of hemorrhagic and non-hemorrhagic human pituitary adenomas were examined. Hemorrhagic pituitary adenomas displayed higher protein and mRNA levels of TNF-α, vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) compared with those of non-hemorrhagic tumors. Exposure of MMQ pituitary adenoma cells to TNF-α induced VEGF and MMP-9 expression in vitro. Additionally, TNF-α administration caused hemorrhagic transformation and enhanced VEGF and MMP-9 expression in MMQ pituitary adenoma cell xenografts in mice. Blockers of VEGF or MMP-9, either alone or in combination, attenuated but not abrogated TNF-α mediated hemorrhagic transformation in xenografts. This study suggests that TNF-α may play a role in the development of intratumoral hemorrhage in pituitary adenomas via up-regulation of VEGF and MMP-9
Trends in the incidence of adenocarcinoma of the oesophagus and cardia in the Netherlands 1989–2003
Over the 15-year period 1989–2003, the incidence of oesophagus–cardia adenocarcinoma in the Netherlands rose annually by 2.6% for males and 1.2% for females. This was the net outcome of annual increases in the incidence of adenocarcinoma of the oesophagus (ACO) of 7.2% for males and 3.5% for females and annual declines in the incidence of adenocarcinoma of the gastric cardia (AGC) of more than 1% for both genders. Nonlinear cohort patterns were found in females with ACO and for both genders in AGC; a nonlinear period pattern was observed only in males with AGC. These differing epidemiological patterns for ACO and AGC do not support a common aetiology. Proposed underlying factors for the rise in ACO incidence appear to have little effect on AGC incidence. This and the secular decline in smoking among males may have led to the decline in AGC incidence
Cost-effectiveness of six strategies for Helicobacter pylori diagnosis and management in uninvestigated dyspepsia assuming a high resource intensity practice pattern
<p>Abstract</p> <p>Background</p> <p>Initial assessment of dyspepsia often includes noninvasive testing for <it>Helicobacter pylori </it>infection. Commercially available tests vary widely in cost and accuracy. Although there is extensive literature on the cost-effectiveness of <it>H. pylori </it>treatment, there is little information comparing the cost-effectiveness of various currently used, noninvasive testing strategies.</p> <p>Methods</p> <p>A Markov simulation was used to calculate cost per symptom-free year and cost per correct diagnosis. Uncertainty in outcomes was estimated using probabilistic sensitivity analysis.</p> <p>Results</p> <p>Under the baseline assumptions, cost per symptom-free year was 123 (stool antigen) to $129 (IgG/IgA combined serology). Confidence intervals had significant overlap.</p> <p>Conclusions</p> <p>Under our assumptions for how testing for <it>H. pylori </it>infection is employed in United States medical practice, the available noninvasive tests all have similar cost-effectiveness between one another as well as with empiric PPI trial.</p
Stromal regulatory T-cells are associated with a favourable prognosis in gastric cancer of the cardia
<p>Abstract</p> <p>Background</p> <p>Recent evidence suggests that CD4<sup>+</sup>CD25<sup>+</sup>FoxP3<sup>+ </sup>regulatory T-cells (Treg) may be responsible for the failure of host anti-tumour immunity by suppressing cytotoxic T- cells. We assessed the prognostic significance of tumour infiltrating lymphocytes (TIL) in intestinal-type gastric cardiac cancer.</p> <p>Methods</p> <p>Tumour infiltrating lymphocyte (TIL) subsets and tumour infiltrating macrophages (TIM) were investigated in 52 cases using tissue microarrays. The interrelationship between the cell populations (CD3+, CD8+, CD20+, CD68+, GranzymeB+, FoxP3+) in different compartments and NED-survival was investigated (median follow-up time: 61 months).</p> <p>Results</p> <p>Intraepithelial infiltration with TIL and TIM including Treg was generally low and not related to NED-survival. However, patients with large numbers of FoxP3<sup>+ </sup>Treg in the tumour stroma (>125.9 FoxP3<sup>+</sup>TILs/mm<sup>2</sup>) had a median survival time of 58 months while those with low FoxP3<sup>+ </sup>TIL counts (<125.9 FoxP3<sup>+</sup>TILs/mm<sup>2</sup>) had a median survival time of 32 months (p = 0.006). Patients with high versus low stromal CD68<sup>+</sup>/FoxP3<sup>+ </sup>cell ratios in primary tumour displayed median survivals of 32 and 55 months, respectively (p = 0.008).</p> <p>Conclusion</p> <p>Our results suggest that inflammatory processes within the tumour stroma of gastric intestinal-type adenocarcinomas located at the gastric cardia may affect outcome in two ways. Tumour-infiltrating macrophages are likely to promote carcinogenesis while large numbers of Treg are associated with improved outcome probably by inhibiting local inflammatory processes promoting carcinogenesis. Thus, inhibition of Treg may not be a feasible treatment option in gastric adenocarcinoma.</p
Effect of treating Schistosoma haematobium infection on Plasmodium falciparum-specific antibody responses
<p>Abstract</p> <p>Background</p> <p>The overlapping geographical and socio-economic distribution of malaria and helminth infection has led to several studies investigating the immunological and pathological interactions of these parasites. This study focuses on the effect of treating schistosome infections on natural human immune responses directed against plasmodia merozoite surface proteins MSP-1 (DPKMWR, MSP1<sub>19</sub>), and MSP-2 (CH150 and Dd2) which are potential vaccine candidates as well as crude malaria (schizont) and schistosome (whole worm homogenate) proteins.</p> <p>Methods</p> <p>IgG1 and IgG3 antibody responses directed against <it>Schistosoma haematobium </it>crude adult worm antigen (WWH) and <it>Plasmodium falciparum </it>antigens (merozoite surface proteins 1/2 and schizont extract), were measured by enzyme linked immunosorbent assay (ELISA) in 117 Zimbabweans (6–18 years old) exposed to <it>S. haematobium </it>and <it>P. falciparum </it>infection. These responses were measured before and after anti-helminth treatment with praziquantel to determine the effects of treatment on anti-plasmodial/schistosome responses.</p> <p>Results</p> <p>There were no significant associations between antibody responses (IgG1/IgG3) directed against <it>P. falciparum </it>and schistosomes before treatment. Six weeks after schistosome treatment there were significant changes in levels of IgG1 directed against schistosome crude antigens, plasmodia crude antigens, MSP-1<sub>19</sub>, MSP-2 (Dd2), and in IgG3 directed against MSP-1<sub>19</sub>. However, only changes in anti-schistosome IgG1 were attributable to the anti-helminth treatment.</p> <p>Conclusion</p> <p>There was no association between anti-<it>P. falciparum </it>and <it>S. haematobium antibody </it>responses in this population and <it>a</it>nti-helminth treatment affected only anti-schistosome responses and not responses against plasmodia crude antigens or MSP-1 and -2 vaccine candidates.</p
Reporting Guidelines for Survey Research: An Analysis of Published Guidance and Reporting Practices
Carol Bennett and colleagues review the evidence and find that there is limited guidance and no consensus on the optimal reporting of survey research
Validade de instrumento epidemiológico para rastrear H. pylori entre pacientes dispépticos
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