A 16-gene signature associated with homologous recombination deficiency for prognosis prediction in patients with triple-negative breast cancer.

Homologous recombination deficiency (HRD) commonly occurs in breast cancer, which is the second cause of cancer death in women with a high rate of relapse and poor outcomes. Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer. Thus, we aim to develop a prognostic signature based on HRD expecting to help improve outcomes in TNBC. The Cancer Genome Atlas (TCGA)-TNBC cohort was divided into the training set and the testing set randomly. Sixteen genes were filtered from the prognostic HRD-associated genes to establish a prognostic model in the training set. Patients were divided into high-risk and low-risk groups based on the median value of the risk score. Prognosis analysis showed that the high-risk group was associated with a worse prognosis in the training set, the testing set, the entire TCGA-TNBC cohort, and the METABRIC-TNBC cohort. The time-dependent receiver operating characteristic curve showed that our model had very good accuracy in the prediction of 1-5-year overall survival in the TCGA-TNBC cohort. Besides, a comparison of the area under curve value and C-index between our model and four published models showed that our model had the best predictive efficiency compared to other models. Subsequently, a nomogram was established. Finally, our finding also indicated that our model was associated with immunoregulation in TNBC and had the potential to be the target for TNBC treatment. Therefore, our findings not only provided a new strategy in the personalized prognosis management of TNBC but also offered new insight into precision treatment in TNBC.

Oblique interface shearing (OIS): single-step microdroplet generation and on-demand positioning.

A new process for simultaneous generation and positioning of microdroplets within a single step named oblique interface shearing (OIS) is reported based on the observation that liquid microdroplets generated by vibrating a thin capillary across the air-liquid interface at an oblique angle exhibit notable lateral displacements. An analytical model is established to describe the lateral droplet displacement induced by the Stokes drift effect. The dependency of the lateral displacement on typical operating parameters allows for on-demand droplet positioning while they are produced. The efficacy of the process is validated through delivering microdroplets with the same size to different positions as well as size-dependent positioning of these microdroplets.

Time-dependent combinatory effects of active mechanical loading and passive topographical cues on cell orientation.

Mechanical stretching and topographical cues are both effective mechanical stimulations for regulating cell morphology, orientation, and behaviors. The competition of these two mechanical stimulations remains largely underexplored. Previous studies have suggested that a small cyclic mechanical strain is not able to reorient cells that have been pre-aligned by relatively large linear microstructures, but can reorient those pre-aligned by small linear micro/nanostructures if the characteristic dimension of these structures is below a certain threshold. Likewise, for micro/nanostructures with a given characteristic dimension, the strain must exceed a certain magnitude to overrule the topographic cues. There are however no in-depth investigations of such "thresholds" due to the lack of close examination of dynamic cell orientation during and shortly after the mechanical loading. In this study, the time-dependent combinatory effects of active and passive mechanical stimulations on cell orientation are investigated by developing a micromechanical stimulator. The results show that the cells pre-aligned by linear micro/nanostructures can be altered by cyclic in-plane strain, regardless of the structure size. During the loading, the micro/nanostructures can resist the reorientation effects by cyclic in-plane strain while the resistive capability (measured by the mean orientation angle change and the reorientation speed) increases with the increasing characteristic dimension. The micro/nanostructures also can recover the cell orientation after the cessation of cyclic in-plane strain, while the recovering capability increases with the characteristic dimension. The previously observed thresholds are largely dependent on the observation time points. In order to accurately evaluate the combinatory effects of the two mechanical stimulations, observations during the active loading with a short time interval or endpoint observations shortly after the loading are preferred. This study provides a microengineering solution to investigate the time-dependent combinatory effects of the active and passive mechanical stimulations and is expected to enhance our understanding of cell responses to complex mechanical environments. Biotechnol. Bioeng. 2016;113: 2191-2201. © 2016 Wiley Periodicals, Inc.

Focus-tunable liquid lens with an aspherical membrane for improved central and peripheral resolutions at high diopters.

Liquid lens offers a simple solution to achieve tunable optical powers. This approach, however, suffers from deteriorated resolution at high diopters. In this study, a plano-convex liquid lens with aspherical cross-section is developed. Such configuration allows for the lens profiles at high diopters to be close to spherical shapes by alleviating the edge-clamping effects. Resolution tests of a 6mm lens with optimized asphericity exhibit improved resolutions in both center and peripheral regions at 40 and 100 diopters than the lenses with planar membranes. It shows that aspherical membranes can improve the resolving power of liquid lenses at high diopters, thus providing a new route of optimizing the imaging performance of adaptive liquid lenses for various applications.