Different Modes Of Acquisition Research Articles

Alternative Methodology for Occupational Dose Estimation in Cardiac Electrophysiology Procedures

Fluoroscopy-guided cardiac electrophysiology procedures are among the most critical x-ray exposures. However, occupational doses are still little-known. In this study, an alternative methodology was developed to estimate the occupational dose and evaluated its optimization in cardiac electro-physiology procedures. The procedures were reproduced by simulation and the dose rates of the staff were measured at chest and eyes height through electronic dosimeters. The dose rate for different modes of operation and FOV were evaluated. The occupational dose was estimated through the product of the dose rate in the staff's position in the room, the median time of exposure and the mean of these procedures performed by the HCPA in 2019. As a result, it was observed that the decreasing order of the estimated occupational dose was Physician A - Physician R - Nursing Staff and Radiographer - Physician B and Supplier, with the following values in mSv/year of 6.16 - 3.98 - 2.54 - 2.17, respectively. A 37.04% reduction in the occupational dose was observed with the change in FOV, up to 59.26% with different modes of acquisition and 31.82% distancing 50 cm from the most exposed position. The dose of staff is significant. However, due to the optimization of protocols already implemented in HCPA, the estimated doses are in accordance with the recommended dose limits. As optimization actions verified in this study, it is suggested the proper selection of FOV, the adoption of acquisition modes with dose reduction and the distance from the x-ray source.

First-generation clinical dual-source photon-counting CT: ultra-low-dose quantitative spectral imaging.

Evaluation of image characteristics at ultra-low radiation dose levels of a first-generation dual-source photon-counting computed tomography (PCCT) compared to a dual-source dual-energy CT (DECT) scanner. A multi-energy CT phantom was imaged with and without an extension ring on both scanners over a range of radiation dose levels (CTDIvol 0.4-15.0 mGy). Scans were performed in different modes of acquisition for PCCT with 120 kVp and DECT with 70/Sn150 kVp and 100/Sn150 kVp. Various tissue inserts were used to characterize the precision and repeatability of Hounsfield units (HUs) on virtual mono-energetic images between 40 and 190 keV. Image noise was additionally investigated at an ultra-low radiation dose to illustrate PCCT's ability to remove electronic background noise. Our results demonstrate the high precision of HU measurements for a wide range of inserts and radiation exposure levels with PCCT. We report high performance for both scanners across a wide range of radiation exposure levels, with PCCT outperforming at low exposures compared to DECT. PCCT scans at the lowest radiation exposures illustrate significant reduction in electronic background noise, with a mean percent reduction of 74% (p value ~ 10-8) compared to DECT 70/Sn150 kVp and 60% (p value ~ 10-6) compared to DECT 100/Sn150 kVp. This paper reports the first experiences with a clinical dual-source PCCT. PCCT provides reliable HUs without disruption from electronic background noise for a wide range of dose values. Diagnostic benefits are not only for quantification at an ultra-low dose but also for imaging of obese patients. PCCT scanners provide precise and reliable Hounsfield units at ultra-low dose levels. The influence of electronic background noise can be removed at ultra-low-dose acquisitions with PCCT. Both spectral platforms have high performance along a wide range of radiation exposure levels, with PCCT outperforming at low radiation exposures.

Simultaneous Improvement in the Precision, Accuracy, and Robustness of Label-free Proteome Quantification by Optimizing Data Manipulation Chains.

The label-free proteome quantification (LFQ) is multistep workflow collectively defined by quantification tools and subsequent data manipulation methods that has been extensively applied in current biomedical, agricultural, and environmental studies. Despite recent advances, in-depth and high-quality quantification remains extremely challenging and requires the optimization of LFQs by comparatively evaluating their performance. However, the evaluation results using different criteria (precision, accuracy, and robustness) vary greatly, and the huge number of potential LFQs becomes one of the bottlenecks in comprehensively optimizing proteome quantification. In this study, a novel strategy, enabling the discovery of the LFQs of simultaneously enhanced performance from thousands of workflows (integrating 18 quantification tools with 3,128 manipulation chains), was therefore proposed. First, the feasibility of achieving simultaneous improvement in the precision, accuracy, and robustness of LFQ was systematically assessed by collectively optimizing its multistep manipulation chains. Second, based on a variety of benchmark datasets acquired by various quantification measurements of different modes of acquisition, this novel strategy successfully identified a number of manipulation chains that simultaneously improved the performance across multiple criteria. Finally, to further enhance proteome quantification and discover the LFQs of optimal performance, an online tool (https://idrblab.org/anpela/) enabling collective performance assessment (from multiple perspectives) of the entire LFQ workflow was developed. This study confirmed the feasibility of achieving simultaneous improvement in precision, accuracy, and robustness. The novel strategy proposed and validated in this study together with the online tool might provide useful guidance for the research field requiring the mass-spectrometry-based LFQ technique.

Prevalence and Epidemiologic Profile of Oral Infection with Alpha, Beta, and Gamma Papillomaviruses in an Asian Chinese Population.

Knowledge of the prevalence of and risk factors for oral human papillomavirus (HPV) infection, especially cutaneous types, is limited. A population-based study using next-generation sequencing consecutively recruited asymptomatic individuals aged 18-64 years from a proportional sampling of the general population of Hong Kong, according to age groups, gender, and regions of residence. We examined associations of alpha-, beta-, and gamma-HPVs from oral rinse samples with participants' sociodemographics by logistic regression models. The prevalence of oral HPV infection among 1426 ethnic Chinese was 15.5% (95% confidence interval [CI], 13.7%-17.5%), 2.5% (95% CI, 1.8%-3.5%), 11.9% (95% CI, 10.3%-13.6%), and 2.9% (95% CI, 2.1%-3.9%) for any type, alpha-, beta-, and gamma-HPV, respectively. Prevalence of any high-risk HPV was 0.8% (95% CI, 0.4%-1.4%), and that of HPV-16 was 0.4% (95% CI, 0.2%-0.8%). HPV-8 and HPV-98 were the most common beta types detected, while HPV-4 and HPV-SD2R were the most common gamma types. Prevalence of alpha- and beta/gamma-HPV infection showed a similar pattern of increase with age, and was higher in men than women. Smoking, drinking, oral sex, and more sexual partners were associated with alpha-HPV. Teeth brushing before sleep was protective for beta/gamma-HPVs. The epidemiologic factors associated with oral infection with alpha-HPVs are different from those of beta/gamma-HPVs, suggesting different modes of acquisition and persistence.

Combined effects of age of onset and input on the development of different grammatical structures

This study investigates the combined effects of Age of Onset of Acquisition (AOA) and quality and quantity of input on the development of three grammatical structures in French. In a longitudinal and multiple case study including successive (L2) Swedish-French bilingual children (n = 3), simultaneous (2L1) Swedish-French bilingual children (n = 3) and monolingual French children (n = 3), we examine the development of finite verb forms, object pronouns and subject-verb agreement. A distinction is made between structures that are early/ late in different modes of acquisition and less/more difficult. The operationalization of quantity and quality of input is based on individual input profiles. The results show that AOA affects the development of less difficult and early grammatical structures whereas AOA has no influence on more difficult structures that are acquired late. An effect of input is found in the 2L1 children, and in some of the L2 children. This effect is most clear with more difficult and late structures.

Imaging performance evaluation of full and binning acquisition modes in a prototype CBCT system equipped with the TFT X-ray detector

The projection number, acquisition time, radiation dose, and full and 2×2 binning modes of the thin film transistor (TFT) X-ray imaging detector were evaluated for image quality in a prototype cone-beam computed tomography (CBCT) built for medical applications. The detector is an amorphous silicon (a-Si) based TFT X-ray detector (PaxScan 4030CB, Varian, Inc.). The a-Si based TFT X-ray detector has a 397×298mm2 active area with 194μm pixel pitch and 2048×1536pixel, of which, 388μm pixel pitch and 1024×768pixel were used for the 2×2 binning mode. The Feldkamp, Davis, and Kress (FDK) reconstruction algorithm was used to generate 3D images, and the comparisons were made between different modes of acquisition. The American Association of Physicists in Medicine (AAPM) computed tomography (CT) performance phantom (model 610, CIRS) and the chest phantom (model 76-683, Nuclear Associates) were used to evaluate the image quality.

Laboratory-based real and reciprocal space imaging of the electronic structure of few layer graphene on SiC(0001¯) using photoelectron emission microscopy

We present real and reciprocal space photoelectron emission microscopy (PEEM) results on few layer graphene using laboratory based He I and II radiation. The combination of a focused high-intensity source and high transmission PEEM electron optics provides good signal to noise ratios for the different modes of acquisition. We demonstrate work function mapping and secondary electron analysis, related to the graphene layer thickness, band structure imaging from micron scale regions by wave vector resolved PEEM (k-PEEM) and local secondary electron spectroscopy, giving information on the valence and conduction band states and the dispersion relations of the π bands. Dark field PEEM is done by selecting the Dirac cone corresponding to the specific rotation of each graphene layer and allows spatial mapping of the commensurate rotation angles. The use of He II radiation increases the volume of reciprocal space accessible to k-PEEM and improves signal to background. The preferential linear polarization of the light source is used to investigate aspects of the electronic chirality near the Dirac cone. Recent developments in sample manipulation and cooling are presented.

Investigation of the Human Brain Metabolome to Identify Potential Markers for Early Diagnosis and Therapeutic Targets of Alzheimer’s Disease

A study combining high resolution mass spectrometry (liquid chromatography-quadrupole time-of-flight-mass spectrometry, UPLC-QTof-MS) and chemometrics for the analysis of post-mortem brain tissue from subjects with Alzheimer's disease (AD) (n = 15) and healthy age-matched controls (n = 15) was undertaken. The huge potential of this metabolomics approach for distinguishing AD cases is underlined by the correct prediction of disease status in 94-97% of cases. Predictive power was confirmed in a blind test set of 60 samples, reaching 100% diagnostic accuracy. The approach also indicated compounds significantly altered in concentration following the onset of human AD. Using orthogonal partial least-squares discriminant analysis (OPLS-DA), a multivariate model was created for both modes of acquisition explaining the maximum amount of variation between sample groups (Positive Mode-R2 = 97%; Q2 = 93%; root mean squared error of validation (RMSEV) = 13%; Negative Mode-R2 = 99%; Q2 = 92%; RMSEV = 15%). In brain extracts, 1264 and 1457 ions of interest were detected for the different modes of acquisition (positive and negative, respectively). Incorporation of gender into the model increased predictive accuracy and decreased RMSEV values. High resolution UPLC-QTof-MS has not previously been employed to biochemically profile post-mortem brain tissue, and the novel methods described and validated herein prove its potential for making new discoveries related to the etiology, pathophysiology, and treatment of degenerative brain disorders.

Developing a measure of risk adjusted revenue (RAR) in credit cards market: Implications for customer relationship management

Current models of customer lifetime value (CLV) consider the discounted value of profits that a customer generates over an expected lifetime of relationship with the firm. This practice can be misleading in the financial services markets because it ignores the risk posed by the customer (such as delinquency and default). Specifically, in the credit card market, the correlation between revenue and risk is positive. Therefore, firms need to adjust a customer’s profits for the associated risk before developing a measure of customer lifetime value. We propose a new measure, risk adjusted revenue (RAR), that can incorporate multiple sources of risk and demonstrate the usefulness of the proposed measure in correctly assessing the value of a customer in the credit card market. The model can be extended to compute risk adjusted lifetime value (RALTV). We use the RAR metric to understand the effectiveness of different modes of acquisition, and of retention strategies such as affinity cards and reward cards. We find that both reward- and affinity-cardholders generate higher RAR than non-reward and non-affinity cardholders respectively. The ordering of different modes of acquisition with respect to RAR (in decreasing order) is as follows: Internet, direct mail, telesales, and direct selling.

Hysterosalpingography using a flat panel unit: Evaluation and optimization of ovarian radiation dose

The aim of the present study was the evaluation and optimization of radiation dose to the ovaries (D) in hysterosalpingography (HSG). The study included a phantom study and a clinical one. In the phantom study, we evaluated imaging results for different geometrical setups and irradiation conditions. In the clinical study, 34 women were assigned into three different fluoroscopy modes and D was estimated with direct cervical TLD measurements. In the phantom study, we used a source-to-image-distance (SID) of 110 cm and a field diagonal of 48 cm, and thus decreased air KERMA rate (KR) by 19% and 70%, respectively, for beam filtration: 4 mm Al and 0.9 mm Cu (Low dose). The least radiation exposure was accomplished by using the 3.75 pps fluoroscopy mode in conjunction with beam filtration: Low dose. In the clinical study, D normalized to 50 s of fluoroscopy time with a 3.75 pps fluoroscopy mode reached a value of 0.45 ± 0.04 mGy. Observers' evaluation of diagnostic image quality did not significantly differ for the three different modes of acquisition that were compared. Digital spot radiographs could be omitted in modern flat panel systems during HSG. Fluoroscopy image acquisitions in a modern flat panel unit at 3.75 pps and a beam filtration of 4 mm Al and 0.9 mm Cu demonstrate acceptable image quality with an average D equal to 0.45 mGy. This value is lower compared to the studied literature. For these reasons, the proposed method may be recommended for routine HSG examination in order to limit radiation exposure to the ovaries.

The acquisition of French as a second language

1. Articles 2. The acquisition of French as a second language: New developmental perspectives (by Bardel, Camilla) 3. Articles 4. Synthese retrospective et nouvelles perspectives developpementales: Les recherches acquisitionnelles en francais L2 a l'Universite de Stockholm (by Bartning, Inge) 5. Pragmatic use of temporal adverbs in L1 and L2 French: Functions and syntactic positions of textual markers in a spoken corpus (by Hancock, Victorine) 6. La dislocation dans le francais oral d'apprenants suedophones: Emploi et developpement (by Engel, Hugues) 7. Vocabulary aspects of advanced L2 French: Do lexical formulaic sequences and lexical richness develop at the same rate? (by Lundell, Fanny Forsberg) 8. Formulaic and proceduralised language in the initial and advanced stages of learning French (by Towell, Richard J.) 9. The acquisition of additive scope particles by Moroccan Arabic L1 learners of French (by Veronique, Georges Daniel) 10. Development of object clitics in child L2 French: A comparison of developmental sequences in different modes of acquisition (by Granfeldt, Jonas) 11. Subject index

Non-collinear magnetic profile in (Rh/Fe1−xCox)2/Rh(001) bilayer probed by polarized soft x-ray resonant magnetic reflectivity

Magnetization configuration in Fe/Rh/Fe0.5Co0.5/Rh(001) can be non-orthogonal due to competition between the anisotropy and the exchange coupling. Soft x-ray resonant magnetic reflectivity allows us to probe the magnetic profile along the growth axis with in-plane and perpendicular magnetization components. By using different modes of acquisition, we show that it is possible to determine separately the magnetic profile of both magnetization components. Measurements at the Co L3-edge enable us to investigate the magnetism of the alloy layer independently from the layer of Fe.

A novel ant colony optimization algorithm for large-distorted fingerprint matching

Large distortion may be introduced by non-orthogonal finger pressure and 3D-2D mapping during the process of fingerprint capturing. Furthermore, large variations in resolution and geometric distortion may exist among the fingerprint images acquired from different types of sensors. This distortion greatly challenges the traditional minutiae-based fingerprint matching algorithms. In this paper, we propose a novel ant colony optimization algorithm to establish minutiae correspondences in large-distorted fingerprints. First, minutiae similarity is measured by local features, and an assignment graph is constructed by local search. Then, the minutiae correspondences are established by a pseudo-greedy rule and local propagation, and the pheromone matrix is updated by the local and global update rules. Finally, the minutiae correspondences that maximize the matching score are selected as the matching result. To compensate resolution difference of fingerprint images captured from disparate sensors, a common resolution method is adopted. The proposed method is tested on FVC2004 DB1 and a FINGERPASS cross-matching database established by our lab. The experimental results demonstrate that the proposed algorithm can effectively improve the performance of large-distorted fingerprint matching, especially for those fingerprint images acquired from different modes of acquisition.

Compliance with therapy in patients with chronic hepatitis C: associations with psychiatric symptoms, interpersonal problems, and mode of acquisition.

Tolerance of interferon-a therapy for hepatitis C is often poor and medication is expensive. Compliance with diagnostic procedures and, even more important, with medical treatment is obviously critical to minimize the rate of dropouts and to maximize cost efficiency. Moreover, a good concordance with scheduled follow-ups is important for early recognition and treatment of interferon-associated side effects. Therefore, we investigated psychiatric symptoms, interpersonal problems, different modes of acquisition, and sociodemographic factors in HCV-infected patients as possible predictor variables of good versus poor compliance. In a longitudinal study, 74 patients with chronic hepatitis C (CHC) who fulfilled the criteria for treatment with interferon (IFN)-alpha-2b with or without ribavirin were investigated prospectively to identify those at risk for poor compliance during IFN medication. To assess predictive factors, we used both IIP-C (Inventory of Interpersonal Problems) and SCL-90-R (Symptom Check List 90 Items Revised) as psychometric instruments. Sociodemographic and somatic variables as well as compliance during IFN therapy were also evaluated. Poor compliance before or during medication was demonstrated by 23% (N = 17) of HCV patients. Sociodemographic factors and mode of acquisition, particularly former intravenous drug (IVD) abuse were not significantly linked with compliance. Logistic regression analysis demonstrated that the subgroup of patients with compliance problems was best identified by both pretherapeutic psychiatric symptoms and interpersonal problems. Predictive value was best and significant for anger-hostility (P = 0.009), intrusive (P = 0.014), depression (P = 0.015), and phobic anxiety (P = 0.049). Adopting this statistical prediction model, sensitivity was 47.1%, but specificity reached 98.3%. In total, 86.5% of cases were classified correctly. In situations of unclear indication for IFN therapy, psychological variables assessment of before the beginning of treatment may represent an additional decision-making factor.

Cytokine release of peripheral blood mononuclear cells in children with chronic hepatitis B virus infection.

Immune response to hepatitis B virus (HBV) antigens or mitogens in Asian children with chronic HBV infection who are mainly perinatally infected has not been studied in connection with the production of various cytokines, although these patients are considered to be less responsive to antiviral therapy. The production of the cytokines interferon (IFN)-gamma, lymphotoxin, interleukin (IL)-4, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-1beta by peripheral blood mononuclear cells (PBMCs) was studied in 17 hepatitis B surface antigen (HBsAg) carrier children with raised alanine transferase levels (group 1), 17 HBsAg carrier children with normal alanine transferase levels (group 2), and 20 healthy noncarrier control subjects (group 3). Hepatitis B core antigen (HBcAg)-stimulated IFN-gamma production was significantly higher in group 1 than in groups 2 and 3, serum HBeAg cleared within 1 year in five of eight children in group 1 with stimulation indexes higher than 3, and HBcAg-induced IL-4 secretion was minimal in all groups. Interferon-gamma produced by PBMCs stimulated by purified HBsAg did not differ among the three groups. Higher lymphotoxin production by PBMCs stimulated by HBcAg was also noted in groups 1 and 2 than in group 3. Lipopolysaccharide (LPS)-stimulated TNF-alpha production by PBMCs was significantly higher in group 1 than in group 2. There was no association between HBeAg-anti-HBe status and production of various cytokines. No differences were seen in the profile of cytokines induced by HBV antigens or LPS in children of carrier mothers compared with children of HBsAg-negative mothers. Increased IFN-gamma production resulting from HBcAg-specific T-helper lymphocyte type 1 response, and increased TNF-alpha production may contribute to cell-mediated antiviral immune response in children with chronic hepatitis B. In HBV carrier children, the ability to produce the studied cytokines is related to whether an endogenous immune attempt to eliminate HBV infection emerges in the patients but is not related to the different modes of acquisition of HBV infection.

Acquisition of Oil Rights under Contractual Joint Ventures in Nigeria

This article inquires critically into the different modes of acquisition of oil rights in Nigeria by international oil companies (IOCs) under contractual joint ventures. These contractual joint ventures are either production sharing or service contracts.

TcU-Abhängigkeit von Akquisitionszeitpunkt, ROI und Untergrundsubtraktion

Thyroid uptake of 99mTc was compared using different modes of acquisition and evaluation. The starting time of acquisition, 5 min or 20 min after injection, did not make any difference. Comparison of the rectangular standard ROI and an irregular thyroid-shaped ROI showed a slight overestimation by 0.26% for the rectangular ROI. The results demonstrate that certain differences in acquisition and evaluation of TcU are clinically not important; however, if normal values are to be defined, they have to be taken into account.

Relations between Different Modes of Acquisition of the Remanent Magnetization of Ferromagnetic Particles

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