Purpose:
Iterative reconstruction (IR) algorithms have the potential to reduce radiation
dose in
CT diagnostic
imaging. As these algorithms become available on the market, a
standardizable method of ...quantifying the dose reduction that a particular IR method can achieve
would be valuable. Such a method would assist manufacturers in making promotional claims
about dose
reduction, buyers in comparing different devices, physicists in independently validating
the claims, and the United States Food and Drug Administration in regulating the
labeling of CT
devices. However, the nonlinear nature of commercially available IR algorithms poses
challenges to objectively assessing image quality, a necessary step in
establishing the amount of dose reduction that a given IR algorithm can achieve without
compromising that image quality. This review paper seeks to consolidate information
relevant to objectively assessing the quality of CT IR images, and
thereby measuring the level of dose reduction that a given IR algorithm can achieve.
Methods:
The authors discuss task-based methods for assessing the quality of CT IR images and
evaluating dose
reduction.
Results:
The authors explain and review recent literature on signal detection and localization
tasks in CT IR
image quality
assessment, the design of an appropriate phantom for these tasks,
possible choices of observers (including human and model observers), and methods of
evaluating observer performance.
Conclusions:
Standardizing the measurement of dose reduction is a problem of broad interest to the
CT community
and to public health. A necessary step in the process is the objective assessment of
CT
image quality, for which various task-based methods may be suitable.
This paper attempts to consolidate recent literature that is relevant to the development
and implementation of task-based methods for the assessment of CT IR image
quality.
Using 5326 days of atmospheric neutrino data, a search for atmospheric tau neutrino appearance has been performed in the Super-Kamiokande experiment. Super-Kamiokande measures the tau normalization ...to be 1.47±0.32 under the assumption of normal neutrino hierarchy, relative to the expectation of unity with neutrino oscillation. The result excludes the hypothesis of no-tau appearance with a significance level of 4.6σ. The inclusive charged-current tau neutrino cross section averaged by the tau neutrino flux at Super-Kamiokande is measured to be (0.94±0.20)×10−38 cm2. The measurement is consistent with the Standard Model prediction, agreeing to within 1.5σ.
Summary
Nitrification of excess ammonia in soil causes eutrophication of water resources and emission of atmospheric N2O gas. The first step of nitrification, ammonia oxidation, is mediated by ...Archaea as well as Bacteria. The physiological reactions mediated by ammonia‐oxidizing archaea (AOA) and their contribution to soil nitrification are still unclear. Results of non‐culture‐based studies have shown the thaumarchaeotal group I.1b lineage of AOA to be dominant over both AOA of group I.1a and ammonia‐oxidizing bacteria in various soils. We obtained from an agricultural soil a highly enriched ammonia‐oxidizing culture dominated by a single archaeal population c. 90% of total cells, as determined microscopically (by fluorescence in situ hybridization) and by quantitative PCR of its 16S rRNA gene. The archaeon (termed ‘strain JG1’) fell within thaumarchaeotal group I.1b and was related to the moderately thermophilic archaeon, Candidatus Nitrososphaera gargensis, and the mesophilic archaeon, Ca. Nitrososphaera viennensis with 97.0% and 99.1% 16S rRNA gene sequence similarity respectively. Strain JG1 was neutrophilic (growth range pH 6.0–8.0) and mesophilic (growth range temperature 25–40°C). The optimum temperature of strain JG1 (35–40°C) is > 10°C higher than that of ammonia‐oxidizing bacteria (AOB). Membrane analysis showed that strain JG1 contained a glycerol dialkyl glycerol tetraether, GDGT‐4, and its regioisomer as major core lipids; this crenarchaeol regioisomer was previously detected in similar abundance in the thermophile, Ca. N. gargensis and has been frequently observed in tropical soils. Substrate uptake assays showed that the affinity of strain JG1 for ammonia and oxygen was much higher than those of AOB. These traits may give a competitive advantage to AOA related to strain JG1 in oligotrophic environments. 13C‐bicarbonate incorporation into archaeal lipids of strain JG1 established its ability to grow autotrophically. Strain JG1 produced a significant amount of N2O gas – implicating AOA as a possible source of N2O emission from soils. Sequences of archaeal amoA and 16S rRNA genes closely related to those of strain JG1 have been retrieved from various terrestrial environments in which lineage of strain JG1 is likely engaged in autotrophic nitrification.
Here, we present a mouse brain protein atlas that covers 17 surgically distinct neuroanatomical regions of the adult mouse brain, each less than 1 mm3 in size. The protein expression levels are ...determined for 6,500 to 7,500 gene protein products from each region and over 12,000 gene protein products for the entire brain, documenting the physiological repertoire of mouse brain proteins in an anatomically resolved and comprehensive manner. We explored the utility of our spatially defined protein profiling methods in a mouse model of Parkinson's disease. We compared the proteome from a vulnerable region (substantia nigra pars compacta) of wild type and parkinsonian mice with that of an adjacent, less vulnerable, region (ventral tegmental area) and identified several proteins that exhibited both spatiotemporal- and genotype-restricted changes. We validated the most robustly altered proteins using an alternative profiling method and found that these modifications may highlight potential new pathways for future studies. This proteomic atlas is a valuable resource that offers a practical framework for investigating the molecular intricacies of normal brain function as well as regional vulnerability in neurological diseases. All of the mouse regional proteome profiling data are published on line at http://mbpa.bprc.ac.cn/.
AIMS: The aim of this study was to investigate the immunostimulatory effects of an exopolysaccharide‐enriched fraction obtained from Bacillus subtilis J92 (B‐EPS). METHODS AND RESULTS: To determine ...the immunostimulatory activities of B‐EPS, we used IFN‐γ‐primed RAW 264·7 macrophages and CD3/CD28‐stimulated splenocytes. Increases in the levels of NO and many cytokines, such as, TNF‐α, IL‐6, and IL‐1β, were observed in IFN‐γ‐primed RAW 264·7 macrophages by Griess reaction and ELISAs respectively. Using Western blotting and qRT‐PCR, we found that B‐EPS increased the protein and mRNA expressions of iNOS and the mRNA expressions of TNF‐α, IL‐6, and IL‐1β. A reporter gene assay and EMSA revealed that B‐EPS up‐regulated the transcriptional activity of NF‐κB by increasing its DNA binding and nuclear translocation. Pretreatment with NF‐κB inhibitors, that is, BAY11‐7082 and PDTC, decreased NO production in IFN‐γ‐primed RAW 264·7 macrophages by B‐EPS. Furthermore, B‐EPS increased the proliferation of and cytokine (IL‐2 and IFN‐γ) production by CD3/CD28‐stimulated splenocytes. In a cyclophosphamide‐induced immunosuppressed mouse model, B‐EPS (5, 15 or 45 mg kg⁻¹, p.o.) restored thymus and spleen indices. B‐EPS also inhibited cyclophosphamide‐induced reductions in neutrophil and lymphocyte numbers. CONCLUSIONS: B‐EPS improves immune function by regulating immunological parameters in IFN‐γ‐primed macrophages, CD3/CD28‐stimulated splenocytes, and in cyclophosphamide‐induced immunosuppressed mice. SIGNIFICANCE AND IMPACT OF THE STUDY: This study suggests that the exopolysaccharides secreted by B. subtilis J92 could be used as immune stimulants.
This study examines whether the availability of traded credit default swaps (CDS) influences the referenced firms' incentive to smooth their performance. We show that with the introduction of CDS ...trading on their debt, CDS-referenced firms (CDS firms) lower both their earnings and cash flow volatility. Specifically, earnings volatility declines faster than cash flow volatility, which is consistent with income smoothing behavior. The effect of CDS trading on performance smoothing is qualitatively similar under different market and economic conditions. These results support the notion that CDS firms smooth their performance to avoid renegotiation with CDS-protected creditors. We also find that CDS firms smooth their cash flows via hedging with derivatives and smooth their earnings using discretionary accruals after the inception of CDS trading.
Anticancer drug‐mediated induction of immunogenic cell death (ICD) blocks metastasis or recurrence in cancer cells by promoting specific immune activity against cancer antigens. However, this ...strategy has failed to afford adequate treatment efficiency. Overcoming the failure of ICD‐mediated cancer therapy, lipid nanoparticles (LNPs) containing cancer cell surface proteins are synthesized using sonication and extrusion without microfluidics. In addition, these LNPs are decorated with high‐mobility group box 1 protein and calreticulin, indicators of ICD, and named artificial ICD LNPs (AiLNPs). Administration of AiLNPs effectively targets dendritic cells (DCs) and induces DC activation in mice. Moreover, treating CT‐26 tumor‐bearing mice with AiLNPs inhibits tumor growth by inducing CT‐26 antigen‐specific T‐cell immunity. Furthermore, AiLNPs containing Lewis lung carcinoma (LLC1) membrane proteins can prevent metastatic LLC1 tumor growth in the lung via LLC1 antigen‐specific T‐cell activation. Finally, AiLNPs synthesized with human breast cancer membrane proteins activate DC‐mediated antigen‐specific T‐cell immunity, effectively killing tumor cells. Therefore, AiLNPs are expected to be developed as a patient‐specific cancer treatment to prevent cancer recurrence and metastasis.
Schematic illustration of Artificial immunogenic cell death lipid nanoparticles (AiLNPs)‐mediated cancer immunotherapy. AiLNP elicits activation and maturation of conventional dendritic cell1 (cDC1) and cDC2 in humans and mice. AiLNP‐induced activation of DCs promotes tumor antigen‐specific helper and cytotoxic T‐cell activation, which further promotes anticancer immunity against colon and lung carcinoma.
How populists engage with media of various types, and are treated by those media, are questions of international interest. In the United States, Donald Trump stands out for both his ...populism-inflected campaign style and his success at attracting media attention. This article examines how interactions between candidate communications, social media, partisan media, and news media combined to shape attention to Trump, Clinton, Cruz, and Sanders during the 2015–2016 American presidential primary elections. We identify six major components of the American media system and measure candidates’ efforts to gain attention from them. Our results demonstrate that social media activity, in the form of retweets of candidate posts, provided a significant boost to news media coverage of Trump, but no comparable boost for other candidates. Furthermore, Trump tweeted more at times when he had recently garnered less of a relative advantage in news attention, suggesting he strategically used Twitter to trigger coverage.
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•Valorization of red mud and lipid waste via the thermo-chemical process.•Enhanced energy recovery in the thermo-chemical process using CO2.•Fabrication of biochar composite from red ...mud and lipid waste.•Biodiesel synthesis using biochar composite.
Co-pyrolysis of lipid waste and red mud was investigated to achieve valorization of red mud by fabricating biochar composite. For the further sustainable approach, this study intentionally employed carbon dioxide (CO2) as reaction medium in the co-pyrolysis process. The use of CO2 on co-pyrolysis of lipid waste and red mud enabled manipulation of the carbon distributions between pyrogenic products. CO2 expedited the thermal cracking of lipid waste and further reacted with lipid waste during the thermolysis. These mechanistic roles of CO2 were catalytically enhanced by the presence of mineral phases (Fe2O3) in red mud, thereby resulting in the enhanced formation of CO (40 times more at 550 °C). However, CO2 suppressed dehydrogenation of lipid waste (∼ 50%), which resulted in the different pathway for reducing iron oxide in red mud. Moreover, as an aspect of valorization of red mud, catalytic capability of biochar composite was evaluated. As a case study, biodiesel (FAMEs) were synthesized, and all experimental findings suggested that biochar composite could be an effective catalyst for biodiesel synthesis. As compare to biodiesel synthesis using silica (92% yield at 360 °C), the equivalent biodiesel yield was achieved with the biochar at much lower temperature (130 °C).
Although gradual bone transport may permit the restoration of large-diameter bones, complications are common owing to the long duration of external fixation. In order to reduce such complications, a ...new technique of bone transport involving the use of an external fixator and a locking plate was devised for segmental tibial bone defects. A total of ten patients (nine men, one woman) with a mean age at operation of 40.4 years (16 to 64) underwent distraction osteogenesis with a locking plate to treat previously infected post-traumatic segmental tibial defects. The locking plate was fixed percutaneously to bridge proximal and distal segments, and was followed by external fixation. After docking, percutaneous screws were fixed at the transported segment through plate holes. At the same time, bone grafting was performed at the docking site with the external fixator removed. The mean defect size was 5.9 cm (3.8 to 9.3) and mean external fixation index was 13.4 days/cm (11.8 to 19.5). In all cases, primary union of the docking site and distraction callus was achieved, with an excellent bony result. There was no recurrence of deep infection or osteomyelitis, and with the exception of one patient with a pre-existing peroneal nerve injury, all achieved an excellent or good functional result. With short external fixation times and low complication rates, bone transport with a locking plate could be recommended for patients with segmental tibial defects.
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