The number and nature of silanol groups could be estimated in mesoporous silica prepared with cetyltrimethylammonium bromide (CTMBr) in acidic medium to obtain a material appropriate as a stationary chromatographic phase, using thermogravimetric analysis (TGA) and diffuse reflectance infrared spectroscopy (DRIFT). The temperature-programmed desorption of pyridine in the DRIFT cell was quantitatively correlated to the change in intensity of the two IR bands, 1595 and 1446 cm -1 , assigned to pyridine interacting respectively with hydrogen-bonded and free silanol groups, after the determination of the absorptivities for the two bands. For calcined or solvent extracted samples, the silanol density (3-4 groups/nm 2 ), is represented mainly by hydrogen-bonded silanol groups. A significant increase is obtained by rehydroxylation. Activation by heating above 200 °C promotes the condensation of the vicinal silanol groups.
The S5‐methylation test, an alternative to cytology and HPV16/18 genotyping to triage high‐risk HPV‐positive (hrHPV+) women, has not been widely validated in low‐middle‐income countries (LMICs). We compared S5 to HPV16/18 and cytology to detect cervical intraepithelial neoplasia Grade 2 or worse (CIN2+) and CIN3+ in hrHPV+ women selected from a randomized pragmatic trial of 2661 Colombian women with an earlier‐borderline abnormal cytology. We included all hrHPV+ CIN2 and CIN3+ cases (n = 183) age matched to 183
IntroductionHuman papillomavirus (HPV) testing is replacing cytology in primary screening. Its limited specificity demands using a second (triage) test to better identify women at high-risk of cervical disease. Cytology represents the immediate triage but its low sensitivity might hamper HPV testing sensitivity, particularly in low-income and middle-income countries (LMICs), where cytology performance has been suboptimal. The ESTAMPA (EStudio multicéntrico de TAMizaje y triaje de cáncer de cuello uterino con pruebas del virus del PApiloma humano; Spanish acronym) study will: (1) evaluate the performance of different triage techniques to detect cervical precancer and (2) inform on how to implement HPV-based screening programmes in LMIC.Methods and analysisWomen aged 30–64 years are screened with HPV testing and Pap across 12 study centres in Latin America. Screened positives have colposcopy with biopsy and treatment of lesions. Women with no evident disease are recalled 18 months later for another HPV test; those HPV-positive undergo colposcopy with biopsy and treatment as needed. Biological specimens are collected in different visits for triage testing, which is not used for clinical management. The study outcome is histological high-grade squamous intraepithelial or worse lesions (HSIL+) under the lower anogenital squamous terminology. About 50 000 women will be screened and 500 HSIL+ cases detected (at initial and 18 months screening). Performance measures (sensitivity, specificity and predictive values) of triage techniques to detect HSIL+ will be estimated and compared with adjustment by age and study centre.Ethics and disseminationThe study protocol has been approved by the Ethics Committee of the International Agency for Research on Cancer (IARC), of the Pan American Health Organisation (PAHO) and by those in each participating centre. A Data and Safety Monitoring Board (DSMB) has been established to monitor progress of the study, assure participant safety, advice on scientific conduct and analysis and suggest protocol improvements. Study findings will be published in peer-reviewed journals and presented at scientific meetings.Trial registration numberNCT01881659
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