High efficiency sperm enrichment from forensic mock samples in bubble-based acoustic filtration devices for short tandem repeat (STR) analysis.

A bubble-based acoustofluidic filtration (BAF) microfluidic device, which employs cross-flow filtration (CFF) and acoustic streaming, separates cells with high efficiency for forensic analysis. Forensic samples are typically complex and contain a substantial number of squamous epithelial cells from the female vagina, which tend to have fouling problems during filtration due to their morphological and cell adhesion differences. To overcome this issue, the BAF device utilizes bubble oscillation by bulk acoustic wave (BAW) to generate acoustic streaming, which offers additional hydrodynamic forces for side flushing cleaning and achieves effective removal within a mere 0.5 seconds. Our device is tested with imbalanced cell mixtures of sperm and epithelial cells with large disparity ratios. By concurrently employing CFF and acoustic streaming, the samples with our sperm-enrichment can achieve 91.72-97.78% for the recovery rate and 74.58-89.26% for the purity in the sperm enrichment. They are further subjected to short tandem repeat (STR) profiling, enabling the identification of perpetrators. Notably, even samples with minimal sperm cells demonstrated a significant increase in the male donor DNA ratio, while the peak heights of female alleles became virtually undetectable. The exceptional cell separation capability demonstrated by our BAF device highlights its potential applications in forensic sciences and other areas of cell biology.

The Relationship between the Glenohumeral Joint Internal Rotation Deficit and the Trunk Compensation Movement in Baseball Pitchers.

BACKGROUND AND OBJECTIVES: Glenohumeral joint internal rotation deficit (GIRD) is commonly observed in the dominant arm of baseball pitchers and is limited by horizontal adduction motions. We inferred that when pitchers' generation of internal shoulder rotation and horizontal adduction activity is limited, they may generate compensation movements in other body parts. This study aims to investigate whether pitchers with GIRD generates trunk compensation during pitching where pitching targets were on the lower corner of their non-dominant side. DESIGN: Case-control study. SETTING: Elite senior high school baseball. PARTICIPANTS: Twenty-five senior high school baseball pitchers participated in this study. Twelve pitchers with GIRD were assigned to the experiment group, and the remaining 13 participants to the control group. MAIN OUTCOME MEASURES: Glenohumeral internal/external rotation of both arms and internal/external rotation of the bilateral hip joints were measured. The kinematic values of the trunk when pitching to a target were measured using high-speed infrared cameras. RESULTS: Pitchers with GIRD exhibited significantly greater upper trunk rotation toward the non-dominant side when a baseball was released from their hand (27.39 ± 6.62 degrees), compared with non-GIRD pitchers (20.42 ± 5.97 degrees) (p < 0.05). The total rotation of the pivot leg of pitchers with GIRD (67.54 ± 7.84 degrees) was significantly smaller than that of pitchers without GIRD (74.00 ± 7.07 degrees) (p < 0.05). CONCLUSIONS: GIRD in the dominant arm affected upper trunk rotation during pitching and was associated with the hip range of motion. Future studies could conduct a longitudinal study regarding the relationship between GIRD and other joint injuries of the lower limbs.