Experimental analysis of a pulse tube based new prototype for cells cryopreservation

Cells cryopreservation is crucial for the treatment of several diseases, but the survival rate of the cells is significantly affected by the cooling process. Currently, programmable freezers based on liquid nitrogen technology are usually adopted but these solutions may cause the death of the cells due to undesired crystallization, membrane damage or osmotic shock. In the recent years, pulse tube refrigerators have attracted a lot of interest in many applications because of their intrinsic characteristics. Despite more gradual, the cooling rate of a similar refrigerator needs to be carefully controlled to meet the desired requirements of cells cryopreservation. Therefore, at the premises of Sapienza University of Rome a pulse tube-based prototype has been designed for cells cryopreservation and an experimental tests campaign has been conducted to assess the performance of the system for the scope. A new control logic, able to adjust the supplied voltage to electric heaters for the conditioning of the temperature inside the stand tubes, has been implemented and different configurations evaluated with cooling rate varying in the range 0.5°C/min to 1.5°C/min. The analysis has shown that the proposed control logic is able to cool down the stem cells in all the investigated range with a maximum temperature difference between the mean temperature of the tubes and the theoretical temperature of −7.65°C for the configuration with copper plate and −4.09°C for the configuration with aluminium plate which represents a safe condition. On the contrary, the copper plate allows approximating better the real cooling curve with the theoretical one and achieving a lower temperature variance at cooling rates higher than 1.25°C/min. Although some further efforts are needed to tune the system up, the present work has demonstrated that a pulse tube refrigerator can be technically and commercially adopted as a viable solution for stem cells cryopreservation

“I Didn’t Know What Was Wrong:” How People With Undiagnosed Depression Recognize, Name and Explain Their Distress

BACKGROUND: Diagnostic and treatment delay in depression are due to physician and patient factors. Patients vary in awareness of their depressive symp-toms and ability to bring depression-related concerns to medical attention. OBJECTIVE: To inform interventions to improve recog-nition and management of depression in primary care by understanding patients ’ inner experiences prior to and during the process of seeking treatment. DESIGN: Focus groups, analyzed qualitatively. PARTICIPANTS: One hundred and sixteen adults (79% response) with personal or vicarious history of depres

Ethical and methodological challenges slowing progress in primary care-based suicide prevention: Illustrations from a randomized controlled trial and guidance for future research.

IntroductionDespite the pressing need for primary care-based suicide prevention initiatives and growing acknowledgement of recruitment difficulties and Institutional Review Board (IRB) challenges in suicide research, we are aware of no illustrative examples describing how IRB decisions in the design of a primary care trial can compound recruitment challenges.MethodsThe CDC-funded trial (NCT02986113) of Men and Providers Preventing Suicide aimed to examine the effects of a tailored computer program encourage men with suicidal thoughts (n = 304, ages 35-64) to discuss suicide with a primary care clinician and accept treatment. Before a visit, participants viewed MAPS or a non-tailored control video. Post-visit, both arms were offered telephone collaborative care, as mandated by the institutional review board (IRB). We previously showed that exposure to MAPs led to improvements in communication about suicide in a primary care visit. In this paper, we report data on the study's primary outcome, suicide preparatory behaviors.ResultsAfter screening nearly 4100 men, 48 enrolled. Recruitment challenges, which were exacerabted by an IRB mandate narrowing post-intervention patient management differences between trial arms, limited detection of the effects of MAPS on suicide preparatory behaviors.ConclusionsWhile primary care settings are key sites for suicide prevention trials, issues such as recruitment difficulties and overly restrictive IRB requirements may limit their utility. Methodological innovation to improve recruitment and ethical guidance to inform IRB decision-making are needed