3D printed microfluidic circuitry via multijet-based additive manufacturing.

The miniaturization of integrated fluidic processors affords extensive benefits for chemical and biological fields, yet traditional, monolithic methods of microfabrication present numerous obstacles for the scaling of fluidic operators. Recently, researchers have investigated the use of additive manufacturing or "three-dimensional (3D) printing" technologies - predominantly stereolithography - as a promising alternative for the construction of submillimeter-scale fluidic components. One challenge, however, is that current stereolithography methods lack the ability to simultaneously print sacrificial support materials, which limits the geometric versatility of such approaches. In this work, we investigate the use of multijet modelling (alternatively, polyjet printing) - a layer-by-layer, multi-material inkjetting process - for 3D printing geometrically complex, yet functionally advantageous fluidic components comprised of both static and dynamic physical elements. We examine a fundamental class of 3D printed microfluidic operators, including fluidic capacitors, fluidic diodes, and fluidic transistors. In addition, we evaluate the potential to advance on-chip automation of integrated fluidic systems via geometric modification of component parameters. Theoretical and experimental results for 3D fluidic capacitors demonstrated that transitioning from planar to non-planar diaphragm architectures improved component performance. Flow rectification experiments for 3D printed fluidic diodes revealed a diodicity of 80.6 ± 1.8. Geometry-based gain enhancement for 3D printed fluidic transistors yielded pressure gain of 3.01 ± 0.78. Consistent with additional additive manufacturing methodologies, the use of digitally-transferrable 3D models of fluidic components combined with commercially-available 3D printers could extend the fluidic routing capabilities presented here to researchers in fields beyond the core engineering community.

Use of combining in situ hybridization and immunohistochemistry in detecting human papillomavirus on routine sections in cases of diagnostic uncertainty.

OBJECTIVES: To determine the combined role of in situ hybridization (ISH) and immunohistochemistry (IHC) in the detection of human papilloma virus (HPV) infection in cases of diagnostic uncertainty. DESIGN: A retrospective study. SETTINGS: Department of Histopathology at the University of Zimbabwe and Department of Pathology at the University of Texas Medical Branch at Galveston in Texas, both teaching referral hospitals. SUBJECTS: 23 patients with a diagnosis suggestive but not diagnostic of HPV infection on routine histology sections of uterine cervical biopsies, in which 20 had enough material to complete the study. MAIN OUTCOME MEASURES: Surgical pathology records of cases with morphologic features suggestive but not diagnostic of HPV cases were identified. Representative sections of each case were investigated with ISH and IHC for HPV infection. RESULTS: HPV DNA was detected in 12 cases. The bovine papilloma virus (BPV) antibody immunoreacted with six of the cases and two of these had not been detected by ISH resulting in a combined ISH and IHC, HPV detection of 14 cases. CONCLUSION: This preliminary data seems to support the validity of combining IHC and ISH, even though IHC is less sensitive compared to ISH, it may detect certain HPV types not represented in the DNA probe.

HbE-beta-thalassemia associated with G6PD deficiency.

HbE, beta thalassemia, and G6PD deficiency were demonstrated in a 6-year-old Mexican-American child with anemia, jaundice, and delayed growth. The father was heterozygous for HbE, and the mother for beta-thalassemia and G6PD deficiency. The association of these three diseases should be included in the differential diagnosis of anemia in childhood, particularly after the recent influx of people form Southeast Asia into the United States.