ABSTRACT
A great challenge among communities participating in germplasm repository development is to obtain suitable cryopreservation equipment and devices. Commercial programmable freezers are costly and thus unaffordable to many users. Self-made devices have substantial variability among users, resulting in few opportunities for standardization across communities. The development of open hardware with the increasing accessibility of three-dimensional (3-D) printing offers rapid prototyping and easy fabrication of devices by users around the world at low cost. The present study explored the feasibility of developing operational prototypes of 3-D printed motorized cryopreservation devices for continuous freezing of non-batched samples. A controlled cooling conveyor device (CCCD) was designed and fabricated to cryopreserve sperm samples in straws that were loaded onto chain links suspended over liquid nitrogen held in a Styrofoam box. Cooling rates of 5 to 34 °C/min for 0.5-ml French straws were produced by adjusting the height of conveyor chains, slopes, and liquid nitrogen mass. The plunge temperature (-47 °C to -61 °C) was controlled by adjustment of conveyor speed. The cooling curves from the CCCD were comparable to a commercial programmable freezer. There were no significant differences in post-thaw motility of sperm from ornamental (Koi) common carp (Cyprinus carpio) among samples frozen with the CCCD and those frozen with a commercial programmable freezer. The post-thaw sperm motility was consistent among samples frozen in the CCCD across a 15-min time span. The CCCD prototypes in the present study proved to be feasible and functional as low-cost, customizable, portable, and yet standardizable options for freezing of individual (non-batched) samples. Additional design alternatives are proposed to facilitate further adaptation and development by diverse user communities.
ABSTRACT
This article explores the relationship between hypertension and chronic kidney disease (CKD), and examines lifestyle modification and medication management. About one in three U.S. adults has high blood pressure, and despite this high occurrence, only one-third of patients are actually treated to a goal blood pressure. Reasons for this vary, but can include ineffective patient teaching, lack of understanding, poor lifestyle modifications, sub-optimal treatment adherence, limited access to health care, or failure of healthcare providers to treat hypertension aggressively. There is a clear relationship between hypertension and CKD. Studies focusing on hypertension and CKD have shown that optimal blood pressure control can slow the rate of renal function impairment, regardless of the underlying kidney disease. Medication self-management, lifestyle modifications, and factors that contribute to non-adherence should be consistently addressed while maintaining an understanding of personal and cultural beliefs.
