ZINC-22─A Free Multi-Billion-Scale Database of Tangible Compounds for Ligand Discovery.

Purchasable chemical space has grown rapidly into the tens of billions of molecules, providing unprecedented opportunities for ligand discovery but straining the tools that might exploit these molecules at scale. We have therefore developed ZINC-22, a database of commercially accessible small molecules derived from multi-billion-scale make-on-demand libraries. The new database and tools enable analog searching in this vast new space via a facile GUI, CartBlanche, drawing on similarity methods that scale sublinearly in the number of molecules. The new library also uses data organization methods, enabling rapid lookup of molecules and their physical properties, including conformations, partial atomic charges, c Log P values, and solvation energies, all crucial for molecule docking, which had become slow with older database organizations in previous versions of ZINC. As the libraries have continued to grow, we have been interested in finding whether molecular diversity has suffered, for instance, because certain scaffolds have come to dominate via easy analoging. This has not occurred thus far, and chemical diversity continues to grow with database size, with a log increase in Bemis-Murcko scaffolds for every two-log unit increase in database size. Most new scaffolds come from compounds with the highest heavy atom count. Finally, we consider the implications for databases like ZINC as the libraries grow toward and beyond the trillion-molecule range. ZINC is freely available to everyone and may be accessed at cartblanche22.docking.org, via Globus, and in the Amazon AWS and Oracle OCI clouds.

Comparison of extramural clinical rotation days: did the Pipeline program make a difference?

Extramural clinical rotations are implemented by dental schools for a combination of clinical and didactic or behavioral goals. In the United States, the Pipeline, Profession, and Practice: Community-Based Dental Education program was launched to increase the number of underrepresented minority students who are recruited and retained in dental education, to expand the dental curriculum in cultural competence, and to incorporate community-based extramural rotations into the dental schools' clinical curriculum. The objective of this study was to conduct an impact analysis regarding the change in number of extramural clinical rotation weeks for Pipeline and non-Pipeline program students over the time period of 2003 to 2007. National data from the American Dental Education Association's senior survey and other secondary sources were used to determine what student, school, and community characteristics are associated with a difference in the student report of the number of required weeks they expect to spend during their last year in dental school providing care at extramural clinic settings. Students reported a mean of 7.2 weeks for Pipeline students and 6.4 weeks for non-Pipeline students in 2003, increasing to 8.2 weeks for Pipeline students and 6.6 weeks for non-Pipeline students (p<0.05) in 2007. The multivariable model showed the Pipeline program increased significantly the number of rotational weeks reported by students. Three other variables significantly increased rotation weeks: 1) a lower baseline number of reported weeks in community rotations; 2) a lower level of debt student reported upon graduation; and 3) student reports of a higher orientation toward service to others as a reason to enter dentistry.

Who will serve? Assessing recruitment of underrepresented minority and low-income dental students to increase access to dental care.

This article uses data from the 2007 American Dental Education Association survey of dental school seniors to assess their intentions to serve underserved populations according to the students' underrepresented minority (URM) and income status. Dental school recruitment and retention programs that concentrate exclusively on URM students will not benefit most low-income students since 83 percent of them are not URM. Recruiting URM students leads to more graduating students with intentions to serve minorities. Whether the income of URM students was high or low, about half in each income group stated that more than 25 percent of their patients would be underserved minorities, compared to 28 percent of the low-income non-URM students and 17 percent of the higher income non-URM students. However, our multivariable results suggest that recruitment of both low-income groups (URM and non-URM) rather than high income regardless of ethnicity might be especially helpful in producing graduates who choose public service. URM/income status was not significantly related to serving special care or rural populations.

Reforming dental education: faculty members' perceptions on the continuation of pipeline program changes.

In 2002-03 the Robert Wood Johnson Foundation (RWJF) established the Pipeline, Profession, and Practice: Community-Based Dental Education program to change dental education in the United States. In partnership with The California Endowment, the RWJF awarded grants to fifteen U.S. dental schools that would support them in efforts to recruit more underrepresented minority/low-income (URM/LI) students, add cultural competence training, and increase extramural rotations to sixty days. As the program evaluator, the University of California, Los Angeles, School of Public Health (UCLA-SPH) conducted a survey of dental faculty in 2006 related to the goals of the Pipeline program. In this article, we report faculty perceptions pertaining to the extramural rotations and URM/LI recruitment. The survey was conducted in fourteen U.S. dental schools that received Pipeline grants and had an overall response rate of 60 percent (n=1,027) from the 1,713 faculty members who received the survey. A majority (57 percent) of faculty members strongly agreed that extramural rotations should continue as an integral part of students' education; 51 percent felt the same about the continuation of URM/LI recruitment programs. Multivariate logistic regression analyses revealed that faculty type, perception of extramural rotations being a positive experience, increased student productivity, and school culture were significant determinants of support for continuation of the extramural rotation programs. Determinants of support for continuation of the URM/LI recruitment programs were faculty type, perception of URM/LI recruitment effectiveness, perception of students from diverse backgrounds improving educational experience, and having a school mission statement that supports URM/LI recruitment. Pipeline schools should ensure that their extramural faculty remain key players in the Pipeline programs, widely publicize the programs' successes, and develop a service-oriented culture in order to build and sustain faculty perceptions that these programs should continue as integral parts of the schools' educational mission.

What influences dental students to serve special care patients?

This study examines factors associated with graduating dental students' motivation to deliver services to special care patients. We investigated community context and student characteristics, which would influence potential behavior. Higher percentages of older adults and low-income residents in the community were positively correlated with interest in serving special care populations. Factors which correlated with individual student characteristics included having a father with at least a college education, a higher number of weeks spent in extramural clinical rotations, preparedness to provide care to disabled patients, and service orientation and socially conscious attitudes. Frail elderly and disabled persons have limited access to dental care, which is compounded by a shortage of skilled dental professionals who are willing to treat these populations. Our findings suggest that interest in special care dentistry is partly conditioned by the dental school's demographic and dental market context. This study is important to dental educators and policymakers because the challenge of providing care to the "special patient" will increase in the future.

Influence of contextual environment and community-based dental education on practice plans of graduating seniors.

This study investigated senior dental students' plans to provide care to underserved racial/ethnic minority populations. Three sets of determinants were analyzed: contextual environment, community-based dental education (CBDE), and student characteristics. We analyzed data from the ADEA Survey of Dental School Seniors and administrative data sources to construct contextual variables. Multivariable results show three contextual variables predicted practice plans: greater numbers of federally qualified health centers, higher percentages of underrepresented minorities, and attending a California Pipeline dental school. Regarding CBDE predictors, it was alarming to find seniors who viewed the cultural competency curriculum as inadequate and perceived themselves as less prepared to provide oral health care to diverse populations were also those most likely to serve minority patients. Significant student characteristics included racial/ethnic minority, female gender, older age, lower parent's income, and socially conscious orientation. The study provides evidence that contextual environment, CBDE, and student characteristics were significantly associated with plans to care for underserved patients. Findings suggest if the Pipeline initiative is successful in stimulating reform in U.S. dental schools, future students will develop greater awareness regarding critical access problems and the competencies required to effectively care for diverse populations. In the long term, addressing the problem of dental care access will require the creation of policy, financial, and structural interventions to motivate providers to care for the underserved.

Pipeline, profession, and practice program: evaluating change in dental education.

This article describes the conceptual and analytical framework that will be used to assess the effectiveness of the Pipeline, Profession, and Practice: Community-Based Dental Education Program. The evaluation will use a mixed method qualitative and quantitative data collection, analysis, and triangulation. Baseline measures are reported using data from the 2003 ADEA survey of dental school seniors. Baseline measures show the dental schools are confronting a major recruitment challenge that will require short and long pipeline efforts to attract and retain underrepresented and low-income (URM/LI) persons. Gaps were found between the perceptions of URM and non-URM students in the adequacy of the curricula. The majority of all seniors described the current extramural clinical rotations as positive experiences, but URMs were more likely to report the experience improved their ability to care for diverse groups.

Analysis of federal support for postgraduate general dentistry.

We compared the funding granted by the federal government between 1985 and 1997 to stimulate the growth of AEGD and GPR programs across HRSA regions, states, and populations. Information regarding the number, size, and location of programs available during the time period of 1985 to 1997 was collected. During this period, although the number of programs remained constant, the composition of the programs changed, with AEGD programs increasing by 113 percent and GPR programs decreasing by 13 percent. HRSA Regions 2, 3, and 5 combined offered over 50 percent of all programs. The number of residency positions rose by 28 percent in civilian programs and dropped by 11 percent in Veterans and Military (VA/M) positions. Overall growth in AEGD positions increased 208 percent, while the civilian GPR positions remained constant and the number of VA/M GPR positions dropped by 30 percent. A higher percentage increase in programs occurred in cities of greater than 500,000 population than in less densely populated areas. HRSA spent dollar 41,254,501 in the thirteen-year time frame, and funding by region varied by over a hundredfold. Programs in the least dense population groups were often the least funded. There was great variability in the amount of HRSA money received by state, with fifteen states receiving no funding during the thirteen years. Without HRSA dollars, it is apparent that the postgraduate general dental training program would not have gained the vitality it currently offers. However, attention must be paid to developing programs among states with a lack of infrastructure in dental education and training.