An analytical method to speciate two inorganic As forms arsenite, As(lll) and arsenate, As(V) in indica and japonica types of rice (both husked and polished) and determine the inorganic As ...concentration as the sum of these two was internationally validated. The method can additionally determine two organic As compounds, monomethylarsonic acid and dimethylarsinic acid, in rice as separate LC peaks. The method is based on LC separation and inductively coupled plasma (ICP)-MS detection. The method was evaluated through the International Union of Pure and Applied Chemistry/lnternational Organization for Standardization/AOAC harmonized protocol. Sixteen laboratories from four countries participated in the study, and 13 laboratories returned valid data. Twenty test portions of 10 blind duplicates of indica and japonica type rice samples (both husked and polished) were used in this study. Repeatability RSD (RSDr) and reproducibility RSD (RSDR) were calculated at five concentrations of total inorganic As between 0.03 and 0.68 mg/kg. The RSDr was in a range of 3.8 to 7.7% and the RSDR was in a range of 10 to 36%. These performance characteristics were found to be sufficient for determination of inorganic As at or higher than 0.03 mg/kg. Applicability of the method was estimated to be in a range of 0.02-2.0 mg/kg.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Melanoma is a heterogeneous malignancy. We set out to identify the molecular underpinnings of high-risk melanomas, those that are likely to progress rapidly, metastasize, and result in poor outcomes.
...We examined transcriptome changes from benign states to early-, intermediate-, and late-stage tumors using a set of 78 treatment-naive melanocytic tumors consisting of primary melanomas of the skin and benign melanocytic lesions. We utilized a next-generation sequencing platform that enabled a comprehensive analysis of protein-coding and -noncoding RNA transcripts.
Gene expression changes unequivocally discriminated between benign and malignant states, and a dual epigenetic and immune signature emerged defining this transition. To our knowledge, we discovered previously unrecognized melanoma subtypes. A high-risk primary melanoma subset was distinguished by a 122-epigenetic gene signature ("epigenetic" cluster) and TP53 family gene deregulation (TP53, TP63, and TP73). This subtype associated with poor overall survival and showed enrichment of cell cycle genes. Noncoding repetitive element transcripts (LINEs, SINEs, and ERVs) that can result in immunostimulatory signals recapitulating a state of "viral mimicry" were significantly repressed. The high-risk subtype and its poor predictive characteristics were validated in several independent cohorts. Additionally, primary melanomas distinguished by specific immune signatures ("immune" clusters) were identified.
The TP53 family of genes and genes regulating the epigenetic machinery demonstrate strong prognostic and biological relevance during progression of early disease. Gene expression profiling of protein-coding and -noncoding RNA transcripts may be a better predictor for disease course in melanoma. This study outlines the transcriptional interplay of the cancer cell's epigenome with the immune milieu with potential for future therapeutic targeting.
National Institutes of Health (CA154683, CA158557, CA177940, CA087497-13), Tisch Cancer Institute, Melanoma Research Foundation, the Dow Family Charitable Foundation, and the Icahn School of Medicine at Mount Sinai.
The objective of this study is to perform a meta‐analysis of published data on the effects of active learning on Asian students' performance in science, technology, engineering, and mathematics ...(STEM) subjects. This comprehensive meta-analysis study includes a systematic review of papers related to various active learning approaches and instructional methods such as collaborative learning, experiential learning, discovery-based, group-inquiry-based, problem-based and activity-based learning, specifically the effects these approaches have on Asian students' performance in STEM-related subjects. The Scopus electronic bibliographic database was searched with search terms and dates to identify and extract the relevant studies that met pre-stated inclusion criteria. A main criterion for inclusion of studies in this meta-analysis were Asian students’ exposure to any active learning intervention in STEM-related subjects. Studies that fulfilled the inclusion criteria were processed for data extraction. A total of 2810 full‐text peer reviewed papers published from 2000 to 2020 were analyzed and 38 papers met the inclusion criteria established for the meta-analysis. Effect sizes between experimental (
n
= 2230) and control groups (
n
= 2510) were calculated using means and standard deviations which were collected and summarized for a comprehensive and systematic review based on the compiled data. Using means and standard deviations from the studies, a moderately large effect size (ES = 0.6596) was detected. Analysis of the pre-post effect sizes demonstrated a significantly higher mean effect size thereby indicating a positive effect of active learning on Asian students' performance in STEM subjects. Findings from the meta-analysis in this study provide a comprehensive understanding of the effects of active learning on Asian students' performance in STEM subjects. Finally, the significance and relevance of these findings for future research directions are discussed.
This paper presents a new, yet simple and effective approach to modeling industrial Radio Frequency heating systems, using the wave equation applied in three dimensions instead of the conventional ...electrostatics method. The central idea is that the tank oscillatory circuit is excited using an external source. This then excites the applicator circuit which is then used to heat or dry the processed load. Good agreement was obtained between the experimental and numerical data, namely the S
11
-parameter, phase, and heating patterns for different sized loads and positions.
Experimental studies indicate that in addition to diastolic dysfunction, hypertrophied myocardium can display depressed contractile responses, particularly at rapid heart rates, compounding reserve ...limitations. This study tests whether such abnormalities exist in intact human subjects at physiological paced rates and, if so, whether they are linked to simultaneous rate-dependent deterioration in diastolic function.
Ten subjects with left ventricular hypertrophy (LVH) and 8 normal control subjects were studied. Most LVH patients presented with dyspnea and/or pulmonary edema and had concentric hypertrophy. Since rapid pacing simultaneously alters cardiac filling volumes and pressures, pressure-volume relation analysis was used to better define changes in contractile response. Patients were instrumented with a conductance catheter and micromanometer for pressure-volume data recording and a balloon occluder at the right atrial-inferior vena caval junction to vary filling and thus generate function relations. Data were obtained at baseline and at three atrial pacing rates (100, 120, 150 min-1). In addition, single-beat force-interval data were used to indirectly examine calcium cycling kinetics. LVH subjects demonstrated baseline diastolic abnormalities, including prolonged relaxation, elevated end-diastolic pressure, and reduced chamber compliance. However, systolic function was similar to that in control subjects. With rapid pacing, normal subjects displayed a positive contractile response, whereas this was markedly diminished in LVH subjects. With abrupt termination of pacing and return to slower sinus rhythm, LVH subjects displayed greater initial potentiation followed by a more rapid decline than control subjects, suggesting abnormalities of calcium handling. Despite contractile abnormalities, diastolic function did not further deteriorate with rapid pacing and thus did not appear to be tightly linked to the systolic changes.
Pacing stress in intact human LVH can result in systolic impairment superimposed on preexisting but not worsened diastolic dysfunction. Abnormal calcium handling probably contributes prominently to this response.
Classroom lectures by experts in combination with journal clubs and Web-based discussion forums help graduate students develop critical reasoning skills.
The manifestation and management of spontaneous axillosubclavian vein thrombosis in patients with gastrointestinal stromal tumour (GIST) undergoing oral chemotherapy have never been described. We ...report a patient with a recurrent GIST who was receiving maintenance imatinib yet developed a right axillosubclavian vein thrombotic occlusion. The occluded vein was unresponsive to systemic anticoagulation but was reopened by percutaneous rheolytic thrombectomy and has shown good long-term patency. Thus, for patients with recurrent GIST undergoing imatinib therapy, axillosubclavian vein thrombosis might manifest as a complication and could be managed with rheolytic thrombectomy, which thoroughly removes intravascular thrombus and effectively re-vascularizes the thrombosed vessel uneventfully.
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