The Báa nnilah Program: Results of a Chronic-Illness Self-Management Cluster Randomized Trial with the Apsáalooke Nation.

Indigenous people in Montana are disproportionately affected by chronic illness (CI), a legacy of settler colonialism. Existing programs addressing CI self-management are not appropriate because they are not consonant with Indigenous cultures in general and the Apsáalooke culture specifically. A research partnership between the Apsáalooke (Crow Nation) non-profit organization Messengers for Health and Montana State University co-developed, implemented, and evaluated a CI self-management program for community members. This article examines qualitative and quantitative program impacts using a pragmatic cluster randomized clinical trial design with intervention and waitlist control arms. The quantitative and qualitative data resulted in different stories on the impact of the Báa nnilah program. Neither of the quantitative hypotheses were supported with one exception. The qualitative data showed substantial positive outcomes across multiple areas. We examine why the data sets led to two very different stories, and provide study strengths and limitations, recommendations, and future directions.

Recruitment, retention, and intervention adherence for a chronic illness self-management intervention with the Apsáalooke Nation.

Recruitment, retention, and adherence within health intervention research have been understudied in Indigenous communities, where well-known health disparities exist. The purpose of this paper is to describe planned versus actual recruitment, retention, and adherence strategies and the evaluation of retention and adherence strategies for a community-based research study of a Chronic Illness (CI) self-management intervention within an Indigenous community. A Community-Based Participatory Research (CBPR) approach was used to develop and implement Báa nnilah, a culturally consonant educational intervention to improve CI self-management. Reasons for participant adherence and retention were tracked and recorded over time. A post-intervention survey assessed barriers and facilitators to intervention adherence. Overall, recruitment, retention, and adherence methods were successful in enrolling and maintaining participation. Using a CBPR approach and culturally consonant strategies may assist in meeting recruitment goals and improving sustained participation of community members, thus impacting health disparities among Indigenous communities.

Improving Chronic Illness Self-Management with the Apsáalooke Nation: The Báa nnilah Project, a cluster randomized trial protocol.

Chronic illness (CI) is a major cause of morbidity and mortality for Indigenous people. In Montana, Indigenous communities disproportionately experience CI, a legacy of settler colonialism. For over two decades, Messengers for Health, an Apsáalooke (Crow Indian) non-profit, and Montana State University have partnered to improve community health using a community-based participatory research (CBPR) approach. We developed Báa nnilah, an intervention utilizing community strengths, to improve CI self-management. This manuscript describes the protocol for a cluster randomized trial with two arms: an intervention group and a wait list control group, who both participated in the Báa nnilah program. Enrollment occurred through family/clan networks and community outreach and attended to limitations of existing CI self-management interventions by using an approach and content that were culturally consonant. Participants received program materials, attended seven gatherings focused on improving CI management, and received and shared health information through storytelling based on a conceptual framework from the Apsáalooke culture and incorporating CI self-management strategies. Participant support occurred within partnership dyads during and between gatherings, from community mentors, and by program staff. The study used mixed methods to evaluate the intervention, with qualitative measures including the Short Form Health Survey (SF-12), Patient Health Questionnaire (PHQ-9), Patient Activation Measure (PAM), and a suite of PROMIS measures, various physical tests and qualitative survey responses, semi-structured interviews, and outcomes shared by participants with program staff. We hypothesized that Báa nnilah would significantly improve participant health outcome measures across multiple dimensions with quality of life (QoL) as the primary outcome. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03036189. Registered on 30 January 2017. (From https://clinicaltrials.gov/ct2/show/NCT03036189).

Early childbearing, family support, and staying in school in a Northern Plains American Indian reservation.

American Indian youth experience teen birth and school dropout at higher rates than other racial and ethnic groups in the United States. Early childbearing is associated with adverse health and socioeconomic outcomes, including attenuated education. However, kinship childrearing norms among Northern Plains tribes can support positive experiences of early childbearing. Using a community based participatory research framework, this mixed methods exploratory study engaged high school students from a Northern Plains reservation community to examine youth perceptions of family support and belief in ability to stay in school should they have a child. We elicited youth observations of facilitators and inhibitors to academic achievement for young parents. This research supports the need for strengths-based, gender specific, and family inclusive sexuality education to support young people in their reproductive choices in reservation settings. We highlight the utility of including youth as co-authors and co-researchers in future studies.

Community sharing: Contextualizing Western research notions of contamination within an Indigenous research paradigm.

Báa nnilah is a chronic illness self-management program designed by and for the Apsáalooke (Crow) community. Arising from a collaboration between an Indigenous nonprofit organization and a university-based research team, Báa nnilah's development, implementation, and evaluation have been influenced by both Indigenous and Western research paradigms (WRPs). Báa nnilah was evaluated using a randomized wait-list control group design. In a WRP, contamination, or intervention information shared by the intervention group with the control group, is actively discouraged as it makes ascertaining causality difficult, if not impossible. This approach is not consonant with Apsáalooke cultural values that include the encouragement of sharing helpful information with others, supporting an Indigenous research paradigm's (IRP) goal of benefiting the community. The purpose of this paper is to address contamination and sharing as an area of tension between WRP and IRP. We describe how the concepts of contamination and sharing within Báa nnilah's implementation and evaluation are interpreted differently when viewed from these contrasting paradigms, and set forth a call for greater exploration of Indigenous research approaches for developing, implementing, and evaluating intervention programs in Indigenous communities. (Improving Chronic Illness Management with the Apsáalooke Nation: The Báa nnilah Project.: NCT03036189), ClinicalTrials. gov: NCT03036189).

Psychometric properties of the 7-item version of the Concise Health Risk Tracking Self-Report Scale for rural adults enrolled in an Internet-delivered self-help program for depression.

PURPOSE: Monitoring suicide risk in clinical practice requires valid and reliable assessment instruments. This study evaluated the psychometric properties of the 7-item version of the Concise Health Risk Tracking Self-Report, CHRT-SR7 in a primarily rural population. METHODS: The sample comprised 788 participants (81.7% female) of an effectiveness trial of an internet-based self-help intervention for depression. Participants completed self-report questionnaires, including the CHRT-SR7 , Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, Work and Social Adjustment Scale, Connor-Davidson Resilience Scale-10, and Barriers to Seeking Mental Health Care. Four-week test-retest reliability was calculated for a subsample of 147 participants randomized to a waitlist control group. FINDINGS: The CHRT-SR7 internal consistency was α = 0.80 (total sample), α = 0.80 (women), and α = 0.83 (men). The 4-week test-retest reliability was strong for women (r = 0.78) and moderate for men (r = 0.66). Confirmatory factor analysis supported the original 3-factor solution: Hopelessness (2 items), Perceived Lack of Social Support (2 items), and Current Suicidal Thoughts and Plans (3 items), which was invariant across gender and rural status. Convergent and divergent validity was supported as reflected in significant correlations of the CHRT-SR7 and its subscales with measures of depression, anxiety, adjustment, and resilience. Limitations include the limited demographic diversity (mostly non-Hispanic White women) and reliance on self-report data. CONCLUSIONS: Our findings complement those reported in prior studies of patients with severe depression and support the use of the CHRT-SR7 for measuring suicide risk in rural adults; future studies should further test the instrument's psychometric properties in racial or ethnic minority rural residents.

A comparison of 2 micron inner diameter open tubular column liquid chromatography with pressure-driven isocratic, slip-flow, and electrochromatographic modes of operation: a theoretical study.

Modifications to the flow profile used in open tube capillary liquid chromatography (OT-CLC) include using slip-flow walls and using electroosmosis as a fluid pump as practiced in electrochromatography. These modifications are implemented experimentally by changing the capillary surface and solvent conditions which results in the change of boundary conditions at the capillary wall. In this paper we employ a theory-based study and compare the zone broadening of simple solutes using parabolic flow from a liquid pump, slip-flow from a highly hydrophobic inner surface with water eluent, and electroosmosis for the conditions of pure water and dilute salt utilizing 2 µm inner diameter OT capillaries. In general, the two types of flow other than parabolic exhibit thin zones in the early part of the chromatogram, consistent with previous studies of slip-flow and electroosmotic flow used in electrochromatography. Electrochromatography is shown to yield higher efficiency and less zone broadening than parabolic and slip-flow conditions used in this study. Nonetheless, it is found that the zone standard deviations are shown to be similar for these flow profiles as is the number of plates for these different flow profiles under the conditions utilized here. It is revealed that these modifications do not warrant the effort to maintain the special solvent conditions when compared to gradient elution OT-CLC, which gives a nearly constant peak width throughout the chromatogram, is easiest to implement, and is the method of choice for complex analysis.

Food Insecurity in US Military Veterans.

BACKGROUND: Food insecurity (FI) is an important public health issue for US veterans. For many veterans, civilian life is fraught with service-incurred health issues and socioeconomic challenges, each risk factors for FI. The FI literature on veterans is limited due to insufficient coverage of the topic's complexity and the methods used to study it in this population. No published analysis has evaluated how FI has been examined in US veterans. OBJECTIVES: We assessed how FI has been examined in US military veterans by identifying (1) the major content areas, or domains, studied in association with FI and (2) the existing research gaps. METHODS: A scoping literature review was conducted to map the main research domains of the FI literature and identify knowledge gaps. Electronic database and hand searches identified potentially relevant studies (n = 61). Data extraction, utilizing a standardized set of design parameters, was completed. Duplicate removal and application of inclusion/exclusion criteria resulted in the studies (n = 21) selected for critical review. RESULTS: Eight research domains were determined: FI prevalence, health status, dietary practices, health care utilization, economic instability, homelessness/housing instability, food program participation, and community/emergency preparedness-the most dominant was health status and the least dominant were social determinants (ie, homelessness/housing instability, food program participation). Research on validity and usability of FI assessment methods in veterans was virtually absent. Military service factors, longitudinal effects, FI among women, intervention effectiveness, and other areas lacked sufficient inquiry. CONCLUSION: Research is required on lesser examined content areas and methodology to optimize surveillance and policy for veteran FI.

Twelve-Month Follow-Up to a Fully Automated Internet-Based Cognitive Behavior Therapy Intervention for Rural Adults With Depression Symptoms: Single-Arm Longitudinal Study.

BACKGROUND: Internet-based cognitive behavior therapy (iCBT) interventions have the potential to help individuals with depression, regardless of time and location. Yet, limited information exists on the longer-term (>6 months) effects of iCBT and adherence to these interventions. OBJECTIVE: The primary aim of this study was to evaluate the longitudinal (12 months) effectiveness of a fully automated, self-guided iCBT intervention called Thrive, designed to enhance engagement with a rural population of adults with depression symptoms. The secondary aim was to determine whether the program adherence enhanced the effectiveness of the Thrive intervention. METHODS: We analyzed data from 181 adults who used the Thrive intervention. Using self-reports, participants were evaluated at baseline, 8 weeks, 6 months, and 12 months for the primary outcome of depression symptom severity using the Patient Health Questionnaire-9 (PHQ-9) scale and secondary outcome measures, namely, the Generalized Anxiety Disorder Scale-7 (GAD-7) scores, Work and Social Adjustment Scale (WSAS) scores, Conner-Davidson Resilience Scale-10 (CD-RISC-10) scores, and suicidal ideation (ninth item of the PHQ-9 scale) scores. The Thrive program adherence was measured using the numbers of program logins, page views, and lessons completed. RESULTS: The assessment response rates for 8-week, 6-month, and 12-month outcomes were 58.6% (106/181), 50.3% (91/181), and 51.4% (93/181), respectively. By 8 weeks, significant improvements were observed for all outcome measures. These improvements were maintained at 12 months with mean reductions in severities of depression (mean -6.5; P<.001) and anxiety symptoms (mean -4.3; P<.001). Improvements were also observed in work and social functioning (mean -6.9; P<.001) and resilience (mean 4.3; P<.001). Marked decreases were observed in suicidal ideation (PHQ-9 ninth item score >1) at 6 months (16.5%) and 12 months (17.2%) compared to baseline (39.8%) (P<.001). In regard to the program adherence, cumulative counts of page views and lessons completed were significantly related to lower PHQ-9, GAD-7, and WSAS scores and higher CD-RISC-10 scores (all P values <.001 with an exception of page views with WSAS for which P value was .02). CONCLUSIONS: The Thrive intervention was effective at reducing depression and anxiety symptom severity and improving functioning and resilience among a population of adults from mostly rural communities in the United States. These gains were maintained at 1 year. Program adherence, measured by the number of logins and lessons completed, indicates that users who engage more with the program benefit more from the intervention. TRIAL REGISTRATION: ClinicalTrials.gov NCT03244878; https://clinicaltrials.gov/ct2/show/NCT03244878.

Correction: Twelve-Month Follow-Up to a Fully Automated Internet-Based Cognitive Behavior Therapy Intervention for Rural Adults With Depression Symptoms: Single-Arm Longitudinal Study.

[This corrects the article DOI: 10.2196/21336.].

Estimation of low-level components lost through chromatographic separations with finite detection limits.

The search for biomarkers allowing the assessment of disease by early diagnosis is facilitated by liquid chromatography. However, it is not clear how many components are lost due to being present in concentrations below the detection limit and/or being obscured by chromatographic peak overlap. First, we extend the study of missing components undertaken by Enke and Nagels, who employed the log-normal probability density function (pdf) for the distribution of signal intensities (and concentrations) of three mixtures. The Weibull and exponential pdfs, which have a higher probability of small-concentration components than the log-normal pdf, are also investigated. Results show that assessments of the loss of low-intensity signals by curve fitting are ambiguous. Next, we simulate synthetic chromatograms to compare the loss of peaks from superposition (overlap) with neighboring peaks to the loss arising from lying below the limit of detection (LOD) imposed by a finite signal-to-noise ratio (SNR). The simulations are made using amplitude pdfs based on the Enke-Nagels data as functions of relative column efficiency, i.e., saturation, and SNR. Results show that at the highest efficiencies, the lowest-amplitude peaks are lost below the LOD. However, at small and medium efficiencies, peak overlap is the dominant loss mechanism, suggesting that low-level components will not be found easily in liquid chromatography with single channel detectors regardless of SNR. A simple treatment shows that a multichannel detector, e.g., a mass spectrometer, is necessary to expose more low-level components.

Daasachchuchik: A Trauma-Informed Approach to Developing a Chronic Illness Self-Management Program for the Apsáalooke People.

In Montana, American Indians with chronic illnesses (CIs) die 20 years earlier than their White counterparts highlighting an urgent need to develop culturally consonant CI self-management programs. Historical and current trauma places Indigenous peoples at increased health risk relative to others, and negatively influences CI self-management. The Apsáalooke Nation and Montana State University worked together to develop and implement a trauma-informed CI self-management program to improve the Apsáalooke community's health. This paper describes the origins and development of the trauma-informed components of the program. Using community stories and a literature review of trauma-informed interventions, partners co-developed culturally consonant trauma materials and activities grounded in community values and spirituality. Trauma-informed content was woven throughout three intervention gatherings and was the central focus of the gathering, Daasachchuchik ('Strong Heart'). Apsáalooke ancestors survived because of their cultural strengths and resilience; these cultural roots continue to be essential to healing from historical and current trauma.

Type 2 diabetes management among older American Indians: beliefs, attitudes, and practices.

Objective: The purpose of this study was to examine beliefs, attitudes, and practices of older American Indians regarding their type 2 diabetes mellitus (T2DM) management. T2DM is one of the leading causes of morbidity and mortality among American Indians. American Indians are more than twice as likely to have T2DM and have over three times a T2DM mortality rate as Whites. Design: Study participants were older members of a federally recognized tribe who had T2DM. A low-inference qualitative descriptive design was used. Data were collected through semi-structured in-depth qualitative interviews with a mixed inductive, deductive, and reflexive analytic team process. Results: Our study sample included 28 participants with a mean age of 73.0 ± 6.4 years of whom 16 (57%) were women. Participants' mean self-confidence score of successful T2DM management was 8.0 ± 1.7 on a scale from 1 to 10 with 10 representing the greatest amount of confidence. Participants' mean HbA1c was 7.3% ± 1.5%. Overall, participants discussed T2DM management within five themes: 1) sociocultural factors, 2) causes and consequences, 3) cognitive and affective assessment, 4) diet and exercise, and 5) medical management. Conclusions: It is important to be aware of the beliefs and attitudes of patients. Lay understandings can help identify factors underlying health and illness behaviors including motivations to maintain healthy behaviors or to change unhealthy behaviors. Such information can be helpful for health educators and health promotion program staff to ensure their efforts are effective and in alignment with patients' realities.

Putting Self-Management in the Context of Community-Dwelling American Indians Living With Type 2 Diabetes.

PURPOSE: The purpose of this qualitative descriptive study was to examine the National Standards for Diabetes Self-Management Education and Support (DSMES) defined diabetes self-care behaviors (healthy eating, being active, taking medication, monitoring, problem solving, reducing risk, and healthy coping) in the context of older community-dwelling American Indians (AIs). METHODS: Secondary theme analysis of transcribed semistructured qualitative interview data from 28 participants in the Native Elder Care Study aged >60 years identified factors that influence the DSMES self-care behaviors in the context of community-dwelling AIs. RESULTS: Four themes that characterized barriers, facilitators, and opportunities for DSMES to support self-care behaviors included community food security, care partners in self-care, community opportunities for diabetes support, and blending of both health worlds. CONCLUSION: Tribal communities have contemporary strengths and cultural traditions that can be activated to enhance diabetes self-management education and support. Diabetes educators can work in tandem with community health representatives to strengthen the social and community support within which individual AIs with type 2 diabetes mellitus live. Community-based participatory research with AI caregivers, dyads, families, youth, and Indian Health Service clinicians may help to improve tribal food policy and school health initiatives, as well as develop intergenerational interventions for modeling effective diabetes self-management.

Use of a Fully Automated Internet-Based Cognitive Behavior Therapy Intervention in a Community Population of Adults With Depression Symptoms: Randomized Controlled Trial.

BACKGROUND: Although internet-based cognitive behavior therapy (iCBT) interventions can reduce depression symptoms, large differences in their effectiveness exist. OBJECTIVE: The aim of this study was to evaluate the effectiveness of an iCBT intervention called Thrive, which was designed to enhance engagement when delivered as a fully automated, stand-alone intervention to a rural community population of adults with depression symptoms. METHODS: Using no diagnostic or treatment exclusions, 343 adults with depression symptoms were recruited from communities using an open-access website and randomized 1:1 to the Thrive intervention group or the control group. Using self-reports, participants were evaluated at baseline and 4 and 8 weeks for the primary outcome of depression symptom severity and secondary outcome measures of anxiety symptoms, work and social adjustment, psychological resilience, and suicidal ideation. RESULTS: Over the 8-week follow-up period, the intervention group (n=181) had significantly lower depression symptom severity than the control group (n=162; P<.001), with a moderate treatment effect size (d=0.63). Moderate to near-moderate effect sizes favoring the intervention group were observed for anxiety symptoms (P<.001; d=0.47), work/social functioning (P<.001; d=0.39), and resilience (P<.001; d=0.55). Although not significant, the intervention group was 45% less likely than the control group to experience increased suicidal ideation (odds ratio 0.55). CONCLUSIONS: These findings suggest that the Thrive intervention was effective in reducing depression and anxiety symptom severity and improving functioning and resilience among a mostly rural community population of US adults. The effect sizes associated with Thrive were generally larger than those of other iCBT interventions delivered as a fully automated, stand-alone intervention. TRIAL REGISTRATION: ClinicalTrials.gov NCT03244878; https://clinicaltrials.gov/ct2/show/NCT03244878.

Improving chronic illness self-management with the Apsáalooke Nation: Development of the Báa nnilah program.

RATIONALE: Since 1996, members of the Apsáalooke (Crow) Nation and faculty and students at Montana State University have worked in a successful community-based participatory research (CBPR) partnership, leading to increased trust and improvements in health awareness, knowledge, and behaviors. As major barriers to health and healthy behaviors have caused inequities in morbidity and mortality rates for multiple chronic diseases among the Apsáalooke people, community members chose to focus the next phase of research on improving chronic illness management. OBJECTIVE: Existing chronic illness self-management programs include aspects inconsonant with Apsáalooke culture and neglect local factors seen as vital to community members managing their health conditions. The aim of this study was to use CBPR methods grounded in Apsáalooke cultural values to develop an intervention for improving chronic illness self-management. METHOD: Community members shared stories about what it is like to manage their chronic illness, including facilitators and barriers to chronic illness management. A culturally consonant data analysis method was used to develop a locally-based conceptual framework for understanding chronic illness management and an intervention grounded in the local culture. RESULTS: Components of the intervention approach and intervention content are detailed and similarities and differences from other chronic illness management programs are described. CONCLUSIONS: Our collaborative process and product may be helpful for other communities interested in using story data to develop research projects, deepen their understanding of health, and increase health equity.

Frailty in Older American Indians: The Native Elder Care Study.

Introduction: Frailty is often described as a reduction in energy reserves, especially with respect to physical ability and endurance, and it has not been examined in American Indians. The goals of this study were to estimate the prevalence of frailty and identify its correlates in a sample of American Indians. Methods: We examined data from 411 community-dwelling American Indians aged ≥55 years. Frailty was measured with weight loss, exhaustion, low energy expenditure, slowness, and weakness characteristics. Results: Slightly over 44% of participants were classified as pre-frail and 2.9% as frail. Significant correlates of a combined pre-frail and frail status identified in the fully adjusted analyses were younger age, female gender, lower levels of education, increased number of chronic medical conditions, and increased number of activities of daily living limitations. Marital status, chronic pain, and social support were not associated with pre-frail/frail status. Conclusions: Our findings point to specific areas in need of further research, including use of frailty measures that also capture psychosocial components and examining constructs of physical resilience. Targeting those with multiple chronic medical conditions may be an important area in which to intervene, with the goal of reducing risk factors and preventing frailty onset.

Measuring porosities of chromatographic columns utilizing a mass-based total pore-blocking method: Superficially porous particles and pore-blocking critical pressure mechanism.

Experimentally determined total, interstitial and intraparticle porosity values are necessary to equate theory, simulation and experimental column performance. This paper reports a study of a mass-based technique for determining total, interstitial and intraparticle porosity measurements based on the total pore-blocking (TPB) method. Commercially available superficially porous particle (SPP) columns, in a variety of small-pore and wide-pore materials, with both hydrophobic and hydrophilic surfaces, are utilized as samples. The results are compared with previously determined literature values for a number of columns and contrasted with HPLC-based elution methods. This method uses only a high-precision balance and an HPLC pump. A simple theoretical analysis of the TPB method using the Young-Laplace equation shows the pressure bounds and flow rate constraints of the method which ensure pore blocking stability. The results suggest that particles with small-pore diameters can be analyzed over a range of solvent clearing pressures and flow rates. However, wide-pore materials, typically with pore diameters in excess of 400 Å, have very low critical pressures and are difficult to determine without losing the pore blocking component. Small mass differences between clearing solvents are shown to present a challenge for measuring the interstitial volume.

Column selection for comprehensive two-dimensional liquid chromatography using the hydrophobic subtraction model.

Two-dimensional (2D) liquid chromatography (2DLC) methods have grown in popularity due to their enhanced peak capacity that allows for resolving complex samples. Given the large number of commercially available column types, one of the major challenges in implementing 2DLC methods is the selection of suitable column pairs. Column selection is typically informed by chemical intuition with subsequent experimental optimization. In this work a computational screening method for 2DLC is proposed whereby virtual 2D chromatograms are calculated utilizing the Snyder-Dolan hydrophobic subtraction model (HSM) for reversed-phase column selectivity. Towards this end, 319 225 column pairs resulting from the combination of 565 columns and 100 sets of 1000 diverse analytes are examined. Compared to other screening approaches, the present method is highly predictive for column pairs that are able to resolve the largest number of analytes. This approach shows a strong sensitivity to the choice of the second dimension column (having a shorter operating time) and a preference for those with embedded polar moieties, whereas a relatively weak preference for C18 and phenyl columns is found for the first dimension.

Simulation and theory of open-tube dispersion in short and long capillaries with slip boundaries and retention.

Using random walk techniques, high resolution simulations of zone shape are conducted in open capillary tubes for short and long tube conditions. Finite size solutes are used as tracers in this treatment. Slip flow boundary conditions and wall retention are utilized as needed. These simulations are able to reproduce previous work in short and long tubes. For the short tube case where dispersion does not asymptotically approach the classic Taylor-Aris and Golay solutions, the effect of slip flow boundaries in the transient region shows zone shapes with abbreviated tails where the larger slip flow values cause zone compression. The use of slip flow to lower dispersion in capillary-based, wall-coated separations is shown to favor long tube behavior. This is because slip flow is relevant for cases where slip lengths are fractions of small capillary tube diameters. Incorporating slip flow into transport in capillaries favors a very small capillary radius where the cross-sectional diffusion length is very small and sampling times are fast. The purely convective zone shape with slip flow boundaries is derived analytically. Applications for this type of separation, guided by both analytical theory and simulation, show the potential for nano-sized capillary tubes less than 1 µm in diameter and favor very fast isocratic separations. Using long tube retention theory with slip boundaries shows that the dispersion-reducing region is most important in the range 0 ≤ k' ≤ 1, a relatively small retention window. Further discussion of the gradient elution technique and dispersion in packed beds suggests that the general usage of slip flow boundaries is restricted in liquid phase separation systems.