902 research outputs found
Quality control of gasohol using a micro-unit for membraneless gas diffusion
This work describes the development of a new spectrophotometric flow technique suitable for monitoring of ethanol content in gasohol fuel. Membraneless gas-diffusion (MBL-GD) was applied with one-step aqueous extraction of gasohol (1:2 gasohol/water). Segments of aqueous extract and color developing reagent were allowed to flow into two separate channels in the MBL-GD device. Inside the device, ethanol vapor can diffuse across a small headspace between the two channels (donor and acceptor). Introduction of an air-segment behind the zone of acceptor reagent to stop dispersion of the colored zone greatly improves the rapidity of analysis using this MBL-GD technique. Two methods were developed for quality control of gasohol by measuring ethanol content. Method I is suitable for direct calibration of E5 and E10. Method II is recommended for E20. These methods have high accuracy with good precision (% RSD: 1 to 4.9, n = 45) and have a sample throughput of 26 samples per hour. E10 samples were compared with analysis using a standard GC method. </p
Analytical Validation of Multiplex Biomarker Assay to Stratify Colorectal Cancer into Molecular Subtypes.
Previously, we classified colorectal cancers (CRCs) into five CRCAssigner (CRCA) subtypes with different prognoses and potential treatment responses, later consolidated into four consensus molecular subtypes (CMS). Here we demonstrate the analytical development and validation of a custom NanoString nCounter platform-based biomarker assay (NanoCRCA) to stratify CRCs into subtypes. To reduce costs, we switched from the standard nCounter protocol to a custom modified protocol. The assay included a reduced 38-gene panel that was selected using an in-house machine-learning pipeline. We applied NanoCRCA to 413 samples from 355 CRC patients. From the fresh frozen samples (n = 237), a subset had matched microarray/RNAseq profiles (n = 47) or formalin-fixed paraffin-embedded (FFPE) samples (n = 58). We also analyzed a further 118 FFPE samples. We compared the assay results with the CMS classifier, different platforms (microarrays/RNAseq) and gene-set classifiers (38 and the original 786 genes). The standard and modified protocols showed high correlation (> 0.88) for gene expression. Technical replicates were highly correlated (> 0.96). NanoCRCA classified fresh frozen and FFPE samples into all five CRCA subtypes with consistent classification of selected matched fresh frozen/FFPE samples. We demonstrate high and significant subtype concordance across protocols (100%), gene sets (95%), platforms (87%) and with CMS subtypes (75%) when evaluated across multiple datasets. Overall, our NanoCRCA assay with further validation may facilitate prospective validation of CRC subtypes in clinical trials and beyond
Factors Associated with Colposcopy-Histopathology Confirmed Cervical Intraepithelial Neoplasia among HIV-Infected Women from Rio De Janeiro, Brazil
Introduction: Despite the availability of preventive strategies (screening tests and vaccines), cervical cancer continues to
impose a significant health burden in low- and medium-resourced countries. HIV-infected women are at increased risk for
infection with human papillomavirus (HPV) and thus development of cervical squamous intraepithelial neoplasia (CIN).
Methods:Study participants included HIV-infected women enrolling the prospective open cohort of Evandro Chagas
Clinical Research Institute, Oswaldo Cruz Foundation (IPEC/FIOCRUZ). At cohort entry, women were subjected to
conventional Papanicolaou test, HPV-DNA test and colposcopy; lesions suspicious for CIN were biopsied. Histopathology
report was based on directed biopsy or on specimens obtained by excision of the transformation zone or cervical
conization. Poisson regression modeling was used to assess factors associated with CIN2+diagnosis.
Results:The median age of the 366 HIV-infected women included in the study was 34 years (interquartile range: 28–41
years). The prevalence of CIN1, CIN2 and CIN3 were 20.0%, 3.5%, and 2.2%, respectively. One woman was found to have
cervical cancer. The prevalence of CIN2+was 6.0%. Factors associated with CIN2+diagnosis in the multivariate model were
age,years compared to350 cells/mm3 (aPR = 6.03 95%CI 1.50–24.3) and concomitant
diagnosis of vulvar and/or vaginal intraepithelial lesion (aPR = 2.68 95%CI 0.99–7.24).
Discussion:Increased survival through wide-spread use of highly active antiretroviral therapy might allow for the
development of cervical cancer. In Brazil, limited cytology screening and gynecological care adds further complexity to the
HIV-HPV co-infection problem. Integrated HIV care and cervical cancer prevention programs are needed for the prevention
of cervical cancer mortality in this group of wome
A randomized clinical trial on the sealing of occlusal carious lesions: 3–4-year results
Abstract This randomized clinical trial aimed to assess the efficacy of sealing occlusal carious lesions in permanent teeth. The sample consisted of 54 occlusal carious lesions in permanent molars and premolars of 49 patients aged 8–43 years (median: 19 years). The inclusion criteria comprised the presence of a cavity with no access allowing biofilm control. The maximum depth of the lesion was the middle third of the dentin thickness, as assessed by bitewing radiography. The teeth were randomly assigned to sealant treatment (n = 28) or restorative treatment (n = 26). Clinical and radiographic examinations were performed after 1 year and after 3–4 years. The outcomes depended on the clinical performance of the sealant/restoration and the control of caries progression observed radiographically. Survival analysis was performed to assess success rates. Over the 3-4 years of monitoring, 2 sealants were totally lost, 1 needed repair, and 1 showed caries progression, totaling 4 failures in the sealant group. In the restoration group, 1 failure was observed (in need of repair). The success rates were 76% and 94% in the sealant and the restoration groups, respectively (p > 0.05). The sealing of occlusal carious lesions in permanent teeth succeeded in controlling caries over a 3–4-year period. However, sealed carious lesions require patient compliance in attending regular follow-ups to control the occurrence of clinical failures of the sealants
The Mitochondrial Ca(2+) Uniporter: Structure, Function, and Pharmacology.
Mitochondrial Ca(2+) uptake is crucial for an array of cellular functions while an imbalance can elicit cell death. In this chapter, we briefly reviewed the various modes of mitochondrial Ca(2+) uptake and our current understanding of mitochondrial Ca(2+) homeostasis in regards to cell physiology and pathophysiology. Further, this chapter focuses on the molecular identities, intracellular regulators as well as the pharmacology of mitochondrial Ca(2+) uniporter complex
- …