Use Of SAM Research Articles

Contextual influences on simultaneous alcohol and cannabis use in a predominately white sample of college students.

Objective: Simultaneous alcohol and cannabis (i.e., marijuana [SAM]) use is highly prevalent among young adults and college students and associated with a number of negative consequences compared to single substance use. The current study examined socio-contextual factors (e.g., physical, situational, social) associated with SAM use versus cannabis-only versus alcohol-only use. Method: Data were collected from college student SAM users (N = 313, 53% women, M age = 19.79; 74% White; 10% Hispanic/Latinx) who completed two bursts (28 days) of online repeated daily surveys (RDS). RDS were collected five times per day during both bursts (3 months apart). Results: Results suggested that odds of being at home were greater for cannabis-only use compared to SAM and SAM compared to alcohol-only use. Odds of being at a friend's place were greater for SAM compared to alcohol-only and cannabis-only use. Odds of being at a party were greater for SAM compared to alcohol-only use and odds of being at a bar or restaurant were greater for alcohol-only compared to SAM use. Results also suggested that odds of having more people in a location consistently were greater for SAM compared to cannabis-only use, and alcohol-only compared to cannabis-only use. Conclusion: Physical and social contexts (parties, friend's homes, and being around more people) are significantly associated with SAM use occasions. These findings are well-aligned with a social-ecological framework and suggest intervention and prevention efforts should take a comprehensive approach to reduce harms associated with SAM use. Future work is needed to examine these associations in diverse samples. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Associations between simultaneous alcohol and cannabis use and next-day negative affect among young adults: The role of sex and trait anxiety

Background and aimsThe simultaneous use of alcohol and cannabis (“simultaneous alcohol and marijuana [SAM] use”) is common among young adults and associated with negative substance-related consequences. SAM use may be tied to fluctuating mood states such as negative affect and individual characteristics including trait level of anxiety and sex. However, little is understood about their collective role. In this study, we sought to understand the daily link between SAM use and negative affect and whether this link might differ by both trait anxiety and sex. MethodParticipants were 154 young adults (57.8% female, 72.7% White, M age = 20.2) who completed baseline surveys on trait anxiety symptoms and up to 14 consecutive daily surveys on their substance use and affective states. ResultsMultilevel models tested for associations of type of substance use day (i.e., alcohol-only days, cannabis-only days, and no use days relative to SAM use days) with next-day negative affect. Three-way and lower order interactions were tested for substance use day type, anxiety, and sex. Two three-way interactions between cannabis-only days, anxiety, and sex and between alcohol-only days, anxiety, and sex emerged such that SAM use was associated with greater next-day negative affect relative to single substance use days particularly among female participants with elevated anxiety. ConclusionsAnxiety and sex are salient factors in the link between SAM use relative to single-substance use and daily negative affect. Study findings reinforce the need to account for all of these factors in order to develop maximally efficacious substance use interventions.

Young adult simultaneous alcohol and marijuana use: Between- and within-person associations with negative alcohol-related consequences, mental health, and general health across two-years

BackgroundSimultaneous alcohol and marijuana use (SAM) may be linked to both short- and longer-term problems for young adults. Across two years of longitudinal data, we examined between- and monthly within-person associations of alcohol and marijuana use patterns, including SAM, with negative alcohol-related consequences, depressive symptoms, and general health. Methods773 young adults (aged 18–23 at screening; 56% women) who used alcohol in the year prior to study enrollment were surveyed monthly for 24 months. Multilevel models assessed associations of alcohol and marijuana use patterns with outcomes. ResultsIndividuals who reported a higher proportion of SAM months had more negative alcohol-related consequences (Rate Ratio [RR] = 1.49, 95% CI: 1.17,1.89). At the within-person level, participants experienced more alcohol-related consequences on months when SAM was reported compared to months of alcohol-only (RR = 1.17, 95% CI: 1.10,1.25) and months of concurrent alcohol and marijuana use without simultaneous use (CAM; RR = 1.20, 95% CI: 1.11,1.29). Compared to alcohol-only, SAM was associated with more depressive symptoms and poorer general health at the between-person level and with more depressive symptoms at the monthly within-person level; however, SAM did not differ substantially from using neither alcohol nor marijuana or CAM for these outcomes at either the between- or within-person level. ConclusionsSAM use may indicate risk for negative alcohol-related consequences, both within months of SAM use and across more extended time periods. Individuals who engage in SAM may experience worse mental and physical health than individuals who use alcohol exclusively.

Daily-level effects of alcohol, marijuana, and simultaneous use on young adults' perceived sleep health.

Simultaneous alcohol and marijuana (SAM) use is increasingly prevalent among young adults but has adverse health consequences. The current study examined daily-level associations between perceived sleep health and SAM use, relative to non-substance-use days and alcohol- or marijuana-only days. We also estimated linear associations between alcohol/marijuana use and perceived sleep health and explored whether effects were moderated by combined use of alcohol and marijuana. A community sample of SAM-using young adults (N = 409; Mage = 21.61, SD = 2.17; 50.9% female; 48.2% White; 48.9% college students) completed twice-daily surveys for five 14-day sampling bursts. Daily measurements assessed substance use and perceived sleep health in terms of subjective sleep quality, negative impact of sleep on functioning, and symptoms of insomnia. Multilevel models indicated that, relative to non-substance-use days, participants reported poorer perceived sleep health on alcohol-only days, better perceived sleep health on marijuana-only days, and mixed evidence regarding SAM use (i.e. fewer perceived symptoms of insomnia, but poorer perceived next day functioning attributed to sleep). Daily-level estimates showed increased alcohol use was associated with poorer perceived sleep health, while stronger effects from marijuana were associated with better perceived sleep health. Across all indices of sleep health, only one linear association was moderated by combined use: The adverse association between alcohol and next day functioning was weaker on days alcohol was combined with marijuana. Findings provide additional evidence for daily-level effects of alcohol and marijuana use on perceived sleep health and address an important literature gap regarding potential adverse effects of SAM use.

A systematic review of the quality of conduct and reporting of survival analyses of tuberculosis outcomes in Africa

BackgroundSurvival analyses methods (SAMs) are central to analysing time-to-event outcomes. Appropriate application and reporting of such methods are important to ensure correct interpretation of the data. In this study, we systematically review the application and reporting of SAMs in studies of tuberculosis (TB) patients in Africa. It is the first review to assess the application and reporting of SAMs in this context.MethodsSystematic review of studies involving TB patients from Africa published between January 2010 and April 2020 in English language. Studies were eligible if they reported use of SAMs. Application and reporting of SAMs were evaluated based on seven author-defined criteria.ResultsSeventy-six studies were included with patient numbers ranging from 56 to 182,890. Forty-three (57%) studies involved a statistician/epidemiologist. The number of published papers per year applying SAMs increased from two in 2010 to 18 in 2019 (P = 0.004). Sample size estimation was not reported by 67 (88%) studies. A total of 22 (29%) studies did not report summary follow-up time. The survival function was commonly presented using Kaplan-Meier survival curves (n = 51, (67%) studies) and group comparisons were performed using log-rank tests (n = 44, (58%) studies). Sixty seven (91%), 3 (4.1%) and 4 (5.4%) studies reported Cox proportional hazard, competing risk and parametric survival regression models, respectively. A total of 37 (49%) studies had hierarchical clustering, of which 28 (76%) did not adjust for the clustering in the analysis. Reporting was adequate among 4.0, 1.3 and 6.6% studies for sample size estimation, plotting of survival curves and test of survival regression underlying assumptions, respectively. Forty-five (59%), 52 (68%) and 73 (96%) studies adequately reported comparison of survival curves, follow-up time and measures of effect, respectively.ConclusionThe quality of reporting survival analyses remains inadequate despite its increasing application. Because similar reporting deficiencies may be common in other diseases in low- and middle-income countries, reporting guidelines, additional training, and more capacity building are needed along with more vigilance by reviewers and journal editors.

Co-Use of Alcohol and Cannabis: Longitudinal Associations with Mental Health Outcomes in Young Adulthood

Increases in cannabis use among young people has heightened concern about the potential interactive health effects of cannabis with other drugs. We examined the longitudinal association between concurrent and simultaneous (SAM) co-use of alcohol and cannabis in young adulthood on mental health symptoms, substance use behaviors, and substance-related harms two years later. Data were drawn from Time 5 (T5; n = 464; 46% male) and 6 (T6; n = 478; 45% male) of the Victoria Healthy Youth Survey. At T5, 42% of participants used alcohol-only, 13% used concurrently, 41% used SAM, 1% were cannabis only users, and 3% abstained from cannabis and alcohol. Boys were more likely to use SAM. Higher T5 SAM use frequency was associated with heavier use of substances, more substance-related harms, and symptoms of psychosis and externalizing problems at T6. T5 Concurrent use was associated with conduct symptoms, illicit drug use, and alcohol use disorders at T6 relative to alcohol-only use. Cannabis is commonly used with alcohol and the findings suggest that any co-use (concurrent or simultaneous) may be problematic in young adulthood. Public health messages need to explicitly inform consumers about the possible consequences of using both alcohol and marijuana and the addictive pharmacological impact of using them together.

Does the Combination Matter? Examining the Influence of Alcohol and Cannabis Product Combinations on Simultaneous Use and Consequences in Daily Life.

Alcohol and marijuana/cannabis are frequently used simultaneously (i.e., SAM use). SAM use is complex, and the ways in which alcohol and cannabis are simultaneously used may reveal differential effects. The purpose of this study was to examine day-level effects of distinct alcohol and cannabis product combinations on simultaneous use and consequences on that day. College student SAM users (N=274; 50% women; Mage =19.82years) were recruited to complete 54days of data collection, including 5 repeated daily surveys each day. We identified 12 distinct product combinations reported during SAM-use days. We tested 4 reference groups, with one reflecting the most common use pattern and 3 potentially risky use patterns. We considered 3 outcomes (negative consequences, number of drinks, and number of cannabis uses) and used generalized linear mixed-effects models disentangling within- from between-person effects in all analyses. Using multiple products (≥2) of alcohol was consistently linked to higher odds of experiencing a negative consequence. Combining beer with only one cannabis product (leaf or concentrate) was consistently associated with lower odds of a consequence. Combining cannabis with multiple alcohol products was associated with heavier alcohol consumption. Using dual cannabis products also was associated with heavier cannabis consumption, but this pattern was not significantly different than using concentrate only on a given day. This is the first study to examine day-level influences of distinct alcohol and cannabis product combinations on consumption and consequences among young adult SAM users. Findings suggest that mixing alcohol products confers greater risk for negative consequences and heavier consumption, whereas there is little difference in cannabis consumption when using concentrate only vs. 2 cannabis products on a given day, except for concentrate+beer. Our findings support existing protective strategies of not mixing alcohol products and avoiding use of cannabis concentrate for SAM use as well.

1446. The Impact of Enterobacteriaceae Isolate Breakpoints on Prescriber Treatment Choices for Discordant Pattern Urinary Tract Infections

BackgroundOur institution revealed Enterobacteriaceae with discordant cefazolin (CEF)-resistant / ampicillin-sulbactam (SAM) susceptible patterns (CRASS-P). This discordance could be from the multiple MIC cephalosporin breakpoint adjustments from CLSI. SAM has higher resistance for gram-negative bacteria compared with cephalosporins such as CEF which is confirmed by our antibiogram. We sought to understand if narrow-spectrum antibiotic choices for CRASS-P urinary tract infections (UTIs) led to clinical cure (CC).MethodsWe conducted a retrospective review from January 2018 to February 2019 of all CRASS-P Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae isolates from urine cultures. Patients with any symptom related to a UTI, urinalysis with >10 white blood cells/high-powered field, urine culture with >10,000 colony-forming units/mL, and receipt of an antibiotic were included. CC was defined as symptom resolution within 48 hours with no return to care within 28 days of the positive urinary culture. “Group A” included patients prescribed narrow-spectrum antibiotics such SAM, CEF, or an oral cephalosporin (OC) vs. broad-spectrum antibiotics such as ceftriaxone, quinolones or sulfa-medications (“Group B”).ResultsThere were 960/1356 (70.8%) CRASS-P urinary isolates and 244 patients met inclusion criteria. Of 244 patients, 72 were in Group A and 172 were in Group B. There was no difference in the diversity of the 3 uropathogens, P = 0.34 (Table 1). Median age was 69±20.3 and 67.5±23.9 years for Group A and Group B, respectively, P = 0.23. Females accounted for 73.6% and 77.9% in Group A and B, respectively, P = 0.51. Overall, patients reached CC in 98.6% (71/72) of Group A patients, compared with 92.4% (159/172) of Group B patients, P = 0.07. Antibiotics used in treatment are outlined in Figure 1. UTI was associated with bacteremia for 2 patients in Group A and 4 patients in Group B (P = 0.84). Both patients in Group A reached CC and used AMC for treatment. However, 1 out of 4 patients did not achieve CC in Group B.ConclusionThe use of SAM or OC can spare the broad-spectrum antibiotics use for CRASS-P UTIs as there was no statistical difference in CC between the two groups. The use of SAM with CRASS-P bacteremia secondary to UTI is possible; however, future studies are needed. Disclosures All authors: No reported disclosures.

More drugs, more problems? Simultaneous use of alcohol and marijuana at parties among youth and young adults

BackgroundSimultaneous alcohol and marijuana (SAM) use by youth and young adults often occurs at parties and may result in an increased risk of experiencing adverse consequences compared to use of either substance alone. This study sought to examine the relationship between SAM use by youth and young adults and consequences experienced at, or immediately following, parties. MethodsWe conducted a repeated cross-sectional survey of 15 to 20-year-olds residing in 24 communities across seven states within the United States in 2015 and 2016 (n = 2681). Logistic regression analyses were used to examine associations between SAM use and six consequences (e.g. hangover, sex without a condom, involved in a fight) among 834 youth and young adults (53.7% female, 78.3% White, mean age: 18.4 years) who reported using either alcohol or marijuana at the last party they attended. Results72.3% consumed alcohol exclusively, 5.2% used marijuana exclusively, and 22.5% engaged in SAM use. In multivariable analyses, those who reported SAM use had significantly greater odds of experiencing any (AOR = 1.9; 95% CI: 1.3, 2.8) and 2 or more (AOR = 4.0; 95% CI: 2.0, 8.0) consequences compared to those who used only alcohol. ConclusionsOur findings suggest that SAM use in a party context is associated with an increased risk of experiencing consequences among youth and young adults after controlling for the quantity of alcohol consumed. Policy and educational prevention strategies should target SAM at parties to reduce harms among youth and young adults.

Improving the production of S-adenosyl-L-methionine in Escherichia coli by overexpressing metk

ABSTRACTS-adenosyl-L-methionine (SAM) has important applications in many fields including chemical therapy and pharmaceutical industry. In this study, the recombinant Escherichia coli strain was constructed for effective production of SAM by introducing the SAM synthase gene (metK). This strain produced 34.5 mg/L of SAM in basic medium in shake flask. Yeast extract, pH, and loaded volume had a significant positive effect on the yield of SAM. Their optimal values were 35 g/L, 7.5, and 30 mL, respectively. The final conditions optimized were as follows: glucose 20, g/L; peptone, 40 g/L; yeast extract, 35 g/L; NaCl, 10 g/L; MgSO4, 1.2 g/L; L-methionine, 1 g/L; rotate speed, 220 rpm; loaded volume, 30 mL; inoculation, 1%; temperature, 37°C; and initial medium, pH 7.5. The recombinant strain produced 128.2 mg/L of SAM under the above conditions in shake flask. The production of SAM in a 5 L fermentor was also investigated. The maximal biomass of the recombinant strain was 60.4 g/L after the cells were cultured for 20 hr, and the highest yield of SAM was 300.9 mg/L after induction for 8 hr in a 5 L fermentor. This study provides a good foundation for the future production and use of SAM.

Simultaneous alcohol and marijuana use among US high school seniors from 1976 to 2011: Trends, reasons, and situations

BackgroundSimultaneous alcohol and marijuana (SAM) use raises significant concern due to the potential for additive or interactive psychopharmacological effects. However, no nationally representative studies are available that document prevalence, trends, or related factors in US youth SAM use. MethodsNationally representative cross-sectional samples of 12th grade students surveyed in the Monitoring the Future project from 1976 to 2011 provided data on SAM use. Analyses were conducted in 2012. ResultsIn 2011, 23% of all US high school seniors reported any SAM use. Among seniors reporting any past 12-month marijuana use, 62% reported any SAM use and 13% reported SAM use most or every time they used marijuana. SAM use consistently followed trends for past 30-day alcohol use over time. SAM use showed significant variation by psychosocial and demographic characteristics and was strongly associated with higher substance use levels, but occurred across the substance use spectrum. Certain reasons for alcohol or marijuana use (to increase effects of another drug; I’m hooked) and situations of alcohol or marijuana use (park/beach, car, party) were strongly associated with SAM use. ConclusionsA sizable proportion of US high school seniors reported SAM use, and it appeared to occur frequently in social use situations that could impact both the public as well as youth drug users. SAM use appears to be a complex behavior that is incidental to general substance use patterns as well as associated with (a) specific simultaneous reasons (or expectancies), and (b) heavy substance use and perceived dependence, especially on alcohol.

Impedimetric immunosensor for the detection of circulating pro-inflammatory monocytes as infection markers

Circulating blood monocytes belong to the first line of defense against pathogens and inflammation. Monocytes can be divided into three populations defined by the expression of the cell surface molecules, CD 14 and CD 16. The CD 14++ CD 16− cells, called “classical” monocytes, represent 85% to 95% of the total monocytes in a healthy person whereas CD 14− CD 16+, called “proinflammatory” monocytes, are found in greater numbers in the blood of patients with acute inflammation and infectious diseases. This increase in the concentration of proinflammatory monocytes can be a good indicator of an infectious state. This study presents an immunosensor based on impedance detection for specific cell trapping of classical and proinflammatory monocytes. The grafting of specific antibodies (CD 14 or CD 16) was based on the use of mixed SAM associated with protein G. Each step of the functionalization was characterized by electrochemical methods, quartz crystal microbalance and atomic force microscopy. Faradaic electrochemical impedance spectroscopy and voltametric analysis confirmed the success of the modification process with a surface coverage reaching 92% for the antibody layer. The increase in the deposited mass at each step of the modification process confirmed this results revealing that one protein G in two was bound to an antibody. The cell trapping capacity, evaluated by the variation in the film resistance using non-faradaic impedance spectroscopy revealed that the cell trapping is selective, depending on the specific antibody grafted and quantitative with the range of detection being 1000 to 30,000 infected cells. This range of detection is consistent with the application targeted.

Reliable contact fabrication on nanostructured Bi2Te3-based thermoelectric materials

A cost-effective and reliable Ni-Au contact on nanostructured Bi2Te3-based alloys for a solar thermoelectric generator (STEG) is reported. The use of MPS SAMs creates a strong covalent binding and more nucleation sites with even distribution for electroplating contact electrodes on nanostructured thermoelectric materials. A reliable high-performance flat-panel STEG can be obtained by using this new method.

Surface-Enhanced Raman Scattering

The increasing applications of surface-enhanced Raman scattering (SERS) has led to the development of various SERS-active platforms (SERS substrates) for SERS measurement. This work reviews the current optimization techniques available for improving the performance of some of these SERS substrates. The work particularly identifies self-assembled-monolayer(SAM-) based substrate modification for optimum SERS activity and wider applications. An overview of SERS, SAM, and studies involving SAM-modified substrates is highlighted. The focus of the paper then shifts to the use of SAMs to improve analytical applications of SERS substrates by addressing issues including long-term stability, selectivity, reproducibility, and functionalization, and so forth. The paper elaborates on the use of SAMs to achieve optimum SERS enhancement. Specific examples are based on novel multilayered SERS substrates developed in the author’s laboratory where SAMs have been demonstrated as excellent dielectric spacers for improving SERS enhancement more than 20-fold relative to conventional single layer SERS substrates. Such substrate optimization can significantly improve the sensitivity of the SERS method for analyte detection.

Applications of Self-Assembled Monolayers in Surface-Enhanced Raman Scattering

The increasing applications of surface-enhanced Raman scattering (SERS) has led to the development of various SERS-active platforms (SERS substrates) for SERS measurement. This work reviews the current optimization techniques available for improving the performance of some of these SERS substrates. The work particularly identifies self-assembled-monolayer- (SAM-) based substrate modification for optimum SERS activity and wider applications. An overview of SERS, SAM, and studies involving SAM-modified substrates is highlighted. The focus of the paper then shifts to the use of SAMs to improve analytical applications of SERS substrates by addressing issues including long-term stability, selectivity, reproducibility, and functionalization, and so forth. The paper elaborates on the use of SAMs to achieve optimum SERS enhancement. Specific examples are based on novel multilayered SERS substrates developed in the author’s laboratory where SAMs have been demonstrated as excellent dielectric spacers for improving SERS enhancement more than 20-fold relative to conventional single layer SERS substrates. Such substrate optimization can significantly improve the sensitivity of the SERS method for analyte detection.

Ultrafine Particle Sampling with the UNC Passive Aerosol Sampler

A model is presented to describe the collection of ultrafine particles by the UNC passive aerosol sampler. In this model, particle deposition velocity is calculated as a function of particle size, shape and other properties, as well as a function of sampler geometry. To validate the model, deposition velocities were measured for ultrafine particles between 15 and 90 nm in diameter. Passive aerosol samplers were placed in a 1 m 3 test chamber and exposed to an ultrafine aerosol of ammonium fluorescein. SEM images of particles collected by the samplers were taken at 125 kX magnification. Experimental values of deposition velocity were then determined using data from these images and from concurrent measurements of particle concentration and size distribution taken with an SMPS. Deposition velocities from the model and from the experiments were compared and found to agree well. These results suggest that the deposition velocity model presented here can be used to extend the use of the UNC passive aerosol sam...

Gold electrode modified by self-assembled monolayers of thiols to determine DNA sequences hybridization

The process of immobilization of biological molecules is one of the most important steps in the construction of a biosensor. In the case of DNA, the way it exposes its bases can result in electrochemical signals to acceptable levels. The use of self-assembled monolayer that allows a connection to the gold thiol group and DNA binding to an aldehydic ligand resulted in the possibility of determining DNA hybridization. Immobilized single strand of DNA (ssDNA) from calf thymus pre-formed from alkanethiol film was formed by incubating a solution of 2-aminoethanothiol (Cys) followed by glutaraldehyde (Glu). Cyclic voltammetry (CV) was used to characterize the self-assembled monolayer on the gold electrode and, also, to study the immobilization of ssDNA probe and hybridization with the complementary sequence (target ssDNA). The ssDNA probe presents a well-defined oxidation peak at +0.158 V. When the hybridization occurs, this peak disappears which confirms the efficacy of the annealing and the DNA double helix performing without the presence of electroactive indicators. The use of SAM resulted in a stable immobilization of the ssDNA probe, enabling the hybridization detection without labels. This study represents a promising approach for molecular biosensor with sensible and reproducible results.

Thiol versus Selenol SAMs as Nucleation Enhancers and Adhesion Promoters for Plasma Polymerized Pyrrole on Copper Substrates

AbstractThe use of SAMs to enhance the deposition and growth of polypyrrole (PPy) thin films on a copper substrate by plasma‐enhanced chemical vapor deposition (PECVD) is described. The composition, ordering, and compactness of the monolayers is studied by XPS, PM‐IRRAS, and electrochemical techniques in order to determine their quality. Pyrrole plasma polymerization is carried out on SAMs and on bare copper to study the effect of the monolayer in the deposition process. AFM microscopy demonstrates that, because of the pyrrole‐terminated group, PPy nuclei deposit and grow preferably on the SAM‐modified surface. The PPy films deposited on SAMs show very good adhesion to a copper substrate, which makes them good candidates for new electronic components. magnified image

Imaging of Focal Contacts of Chicken Heart Muscle Cells by High-Frequency Acoustic Microscopy

A study of the adhesion of embryonic chicken heart muscle cells was conducted with a newly developed time-resolved acoustic microscope, which operates in the GHz-frequency range. The interpretation of the acoustical images of the heart muscle cells was done in combination with the fluorescence optical microscopy. A comparison between the acoustical images of chicken heart muscle cells and optical images of the same cells after staining showed that the actin fibers end inside the dark streaks in the acoustical images and thus represent the focal contacts (FCs). For cell biology applications, this demonstrates (a) the use of SAM as a tool for studying the dynamics of the FCs of living cells without any chemical staining and (b) that the combination of acoustic and optical microscopes allows interpretation of the acoustical images by using the wide variety of techniques available in optical microscopy. (E-mail: robert.lemor@ibmt.fraunhofer.de)

Self-Assessment for Maintenance of Certification

Self-assessment is paired with continuing medical education in the "lifelong learning " component of the American Board of Radiology's (ABR) Maintenance of Certification program. The literature on the use of self-assessment in higher education and the professions is instructive with regard to the distinctiveness of this form of adult learning. This article reviews pertinent literature, summarizes the findings, and applies the principles to the creation and use of "self-assessment modules" (SAMs) for the maintenance of certification. Data on the use of ABR-qualified SAMs are reported. On completion of this article, the reader should be able to describe the nature, role, and best practices of self-assessment; apply these concepts to the creation or use of a SAM; and identify future opportunities for SAM development and use that will enhance the lifelong learning of radiologists.