Roll-to-roll UV imprint lithography for flexible electronics

We propose a roll-to-roll UV imprint lithography tool as a way to pattern flexible PET foil with µm-resolution. As a way to overcome dimensional instability of the foil and its effect on overlay, a self-align approach was investigated, that permits to make several layers in a single lithography step. Flexible Ni-stamps were used, with a single level and with 2 levels. The stamps were fabricated on wafers using conventional optical lithography and Si etching. Thin Ni replica, both single and multilevel, were obtained by electroplating using a thickness of 50 µm. The flexible Ni stamps were attached on the main drum that is placed on a conventional roll-to-roll machine. Resist was dispensed drop by drop by valve-jet nozzle using solvent-free UV resist. The imprint speed was of 0.35 m/min, using a UV illumination of 2 W. Fifty imprints were made in a row, equivalent to 20 m foil length. High imprint quality was observed with good reproducibility. All features type were replicated, from 500 µm contact pads to 800 nm wide trenches and 1 µm wide lines. A resolution of 800 nm in 1 µm thick resist was obtained for single level imprint. Multi-level imprints (2 levels) show the same quality in replication with a resolution of 1 µm. © 2011 Elsevier B.V. All rights reserved

Predictors of serofast state after treatment for early syphilis in HIV-infected patients

Objectives Non-treponemal serological tests are used to monitor treatment response during syphilis infection. Syphilis- and HIV-coinfected patients may experience incomplete resolution in non-treponemal titres, which is referred to as the serofast state. The goal of this study was to evaluate risk factors for serofast state in HIV-infected patients. Methods From November 2015 to June 2018, 1530 HIV-positive patients were tested for syphilis using a Treponema pallidum particle agglutination (TPPA) assay. Among TPPA-positive patients, medical records were reviewed for early syphilis infection. Serofast state was defined as a less than four-fold decrease in non-treponemal antibody titres during a 6-month follow-up period in the absence of symptoms of syphilis. Baseline characteristics were tested as predictive factors of serological response. Results In all, 515 patients (33.7%) tested positive in TPPA assays, and in 163 patients at least one previous syphilis infection was documented. A total of 61 out of 163 patients (37.4%) were in a serofast state. A history of previous syphilis infection (61 vs. 43%; P = 0.04) was more common in serofast patients than in patients with serological cure after 6 months. Non-treponemal titres >= 1:32 before therapy (47 vs. 25%; P = 0.005) and adjunctive corticosteroids to prevent the Jarisch-Herxheimer reaction (35% vs 15%; P = 0.006) were associated with serological cure after 6 months, but corticosteroid therapy had no influence at 12 months. The intensity of syphilis treatment did not affect serological cure. Conclusion Corticosteroids for prevention of the Jarisch-Herxheimer reaction were associated with earlier serological cure. Although serological response is the accredited surrogate method to monitor syphilis treatment, the biological significance of the serofast state remains unclear

Severe and uncomplicated falciparum malaria in children from three regions and three ethnic groups in Cameroon: prospective study

<p>Abstract</p> <p>Background</p> <p>To identify the factors that account for differences in clinical outcomes of malaria as well as its relationship with ethnicity, transmission intensity and parasite density.</p> <p>Methods</p> <p>A prospective study was conducted in nine health facilities in the Centre, Littoral and South West regions of Cameroon, and in three ethnic groups; the Bantu, Semi-Bantu and Foulbe. Children aged one month to 13 years, with diagnosis suggestive of malaria, were recruited and characterized using the WHO definition for severe and uncomplicated malaria. Malaria parasitaemia was determined by light microscopy, haematological analysis using an automated haematology analyser and glucose level by colorimetric technique.</p> <p>Results</p> <p>Of the febrile children screened, 971 of the febrile children screened fulfilled the inclusion criteria for specific malaria clinical phenotypes. Forty-nine (9.2%) children had cerebral malaria, a feature that was similar across age groups, ethnicity and gender but lower (<it>P</it> < 0.004) in proportion in the Centre (3.1%, 5/163) compared to the Littoral (11.3%, 32/284) and South West (13.6%, 12/88) regions. Severe anaemia was the most frequent severe disease manifestation, 28.0% (248/885), which was similar in proportion across the three ethnic groups but was more prevalent in females, less than 60 months old, and the Centre region. About 20% (53/267) of the participants presented with respiratory distress, a clinical phenotype independent of age, gender and ethnicity, but highest (<it>P</it> < 0.001) in the Centre (55%, 11/20) compared to the Littoral (27.3%, 3/11) and South West (16.5%, 39/236) regions. Uncomplicated malaria constituted 27.7% (255/920) of hospital admissions and was similar in proportion with gender and across the three ethnic groups but more prevalent in older children (≥ 60 months) as well as in the South West region. The density of malaria parasitaemia was generally similar across clinical groups, gender and ethnicity. However, younger children and residents of the Centre region carried significantly higher parasite loads, with the burden heavier in the Semi-Bantu compared to their Bantu (<it>P</it> = 0.009) and Foulbe (<it>P</it> = 0.026) counterparts in the Centre region. The overall study case fatality was 4.8 (47/755), with cerebral malaria being the only significant risk factor associated with death. Severe anaemia, though a common and major clinical presentation, was not significantly associated with risk of death.</p> <p>Conclusion</p> <p>About half of the acutely febrile children presented with severe malaria, the majority being cases of severe malaria anaemia, followed by respiratory distress and cerebral malaria. The latter two were less prevalent in the Centre region compared to the other regions. Cerebral malaria and hyperpyrexia were the only significant risk factors associated with death.</p