Duolayers at the Air/Water Interface: Improved Lifetime through Ionic Interactions.

Ionic interactions to stabilize Langmuir films at the air/water interface have been used to develop improved duolayer films. Two-component mixtures of octadecanoic (stearic) acid and poly(diallyldimethylammonium chloride) (polyDADMAC) with different ratios were prepared and applied to the water surface. Surface pressure isotherm cycles demonstrated a significant improvement in film stability with the inclusion of the polymer. Viscoelastic properties were measured using canal viscometry and oscillating barriers, with both methods showing that the optimum ratio for improved properties was four octadecanoic acid molecules to one DADMAC unit (1:0.25). At this ratio it is expected multiple strong ionic interactions are formed along each polymer chain. Brewster angle microscopy showed decreased domain size with increased ratios of polyDADMAC, indicating that the polymer is interspersed across the surface. This new method to stabilize and increase the viscoelastic properties of charged monolayer films, using a premixed composition, will have application in areas such as water evaporation mitigation, optical devices, and foaming.

Dynamic performance of duolayers at the air/water interface. 2. Mechanistic insights from all-atom simulations.

The novel duolayer system, comprising a monolayer of ethylene glycol monooctadecyl ether (C18E1) and the water-soluble polymer poly(vinylpyrrolidone) (PVP), has been shown to resist forces such as wind stress to a greater degree than the C18E1 monolayer alone. This paper reports all-atom molecular dynamics simulations comparing the monolayer (C18E1 alone) and duolayer systems under an applied force parallel to the air/water interface. The simulations show that, due to the presence of PVP at the interface, the duolayer film exhibits an increase in chain tilt, ordering, and density, as well as a lower lateral velocity compared to the monolayer. These results provide a molecular rationale for the improved performance of the duolayer system under wind conditions, as well as an atomic-level explanation for the observed efficacy of the duolayer system as an evaporation suppressant, which may serve as a useful guide for future development for thin films where resistance to external perturbation is desirable.

Dynamic performance of duolayers at the air/water interface. 1. Experimental analysis.

Understanding, and improving, the behavior of thin surface films under exposure to externally applied forces is important for applications such as mimicking biological membranes, water evaporation mitigation, and recovery of oil spills. This paper demonstrates that the incorporation of a water-soluble polymer into the surface film composition, i.e., formation of a three-duolayer system, shows improved performance under an applied dynamic stress, with an evaporation saving of 84% observed after 16 h, compared to 74% for the insoluble three-monolayer alone. Canal viscometry and spreading rate experiments, performed using the same conditions, demonstrated an increased surface viscosity and faster spreading rate for the three-duolayer system, likely contributing to the observed improvement in dynamic performance. Brewster angle microscopy and dye-tagged polymers were used to visualize the system and demonstrated that the duolayer and monolayer system both form a homogeneous film of uniform, single-molecule thickness, with the excess material compacting into small floating reservoirs on the surface. It was also observed that both components have to be applied to the water surface together in order to achieve improved performance under dynamic conditions. These findings have important implications for the use of surface films in various applications where resistance to external disturbance is required.

Molecular mechanism of stabilization of thin films for improved water evaporation protection.

All-atom molecular dynamics simulations and experimental characterization have been used to examine the structure and dynamics of novel evaporation-suppressing films where the addition of a water-soluble polymer to an ethylene glycol monooctadecyl ether monolayer leads to improved water evaporation resistance. Simulations and Langmuir trough experiments demonstrate the surface activity of poly(vinyl pyrrolidone) (PVP). Subsequent MD simulations performed on the thin films supported by the PVP sublayer show that, at low surface pressures, the polymer tends to concentrate at the film/water interface. The simulated atomic concentration profiles, hydrogen bonding patterns, and mobility analyses of the water-polymer-monolayer interfaces reveal that the presence of PVP increases the atomic density near the monolayer film, improves the film stability, and reduces the mobility of interfacial waters. These observations explain the molecular basis of the improved efficacy of these monolayer/polymer systems for evaporation protection of water and can be used to guide future development of organic thin films for other applications.

Molecular interactions behind the synergistic effect in mixed monolayers of 1-octadecanol and ethylene glycol monooctadecyl ether.

Mixed monolayers of 1-octadecanol (C18OH) and ethylene glycol monooctadecyl ether (C18E1) were studied to assess their evaporation suppressing performance. An unexpected increase in performance and stability was found around the 0.5:0.5 bicomponent mixture and has been ascribed to a synergistic effect of the monolayers. Molecular dynamics simulations have attributed this to an additional hydrogen bonding interaction between the monolayer and water, due to the exposed ether oxygen of C18E1 in the mixed system compared to the same ether oxygen in the pure C18E1 system. This interaction is maximized around the 0.5:0.5 ratio due to the particular interfacial geometry associated with this mixture.

Monolayer structure and evaporation resistance: a molecular dynamics study of octadecanol on water.

This study examines intermolecular interactions of a monolayer of octadecanol (CH(3)(CH(2))(17)OH) on water as a function of surface density and temperature, using classical molecular dynamics simulations. We observe increased interaction between the alkyl chains (van der Waals) and hydroxyl groups (H-bonding) with increased surface density, which leads to increased order and packing within the monolayer. We also identified clear trends in the intermolecular interactions, ordering and packing of the monolayer molecules as a function of temperature. The observed trends can be closely related to features of the current empirical theories of evaporation resistance.

A practice-based intervention to improve primary care for falls, urinary incontinence, and dementia.

OBJECTIVES: To determine whether a practice-based intervention can improve care for falls, urinary incontinence, and cognitive impairment. DESIGN: Controlled trial. SETTING: Two community medical groups. PARTICIPANTS: Community-dwelling patients (357 at intervention sites and 287 at control sites) aged 75 and older identified as having difficulty with falls, incontinence, or cognitive impairment. INTERVENTION: Intervention and control practices received condition case-finding, but only intervention practices received a multicomponent practice-change intervention. MEASUREMENTS: Percentage of quality indicators satisfied measured using a 13-month medical record abstraction. RESULTS: Before the intervention, the quality of care was the same in intervention and control groups. Screening tripled the number of patients identified as needing care for falls, incontinence, or cognitive impairment. During the intervention, overall care for the three conditions was better in the intervention than the control group (41%, 95% confidence interval (CI)=35-46% vs 25%, 95% CI=20-30%, P<.001). Intervention group patients received better care for falls (44% vs 23%, P<.001) and incontinence (37% vs 22%, P<.001) but not for cognitive impairment (44% vs 41%, P=.67) than control group patients. The intervention was more effective for conditions identified by screening than for conditions identified through usual care. CONCLUSION: A practice-based intervention integrated into usual clinical care can improve primary care for falls and urinary incontinence, although even with the intervention, less than half of the recommended care for these conditions was provided. More-intensive interventions, such as embedding intervention components into an electronic medical record, will be needed to adequately improve care for falls and incontinence.

Autophobicity-driven surface segregation and patterning of core-shell microgel nanoparticles.

Core-shell microgel (CSMG) nanoparticles, also referred to as core-cross-linked star (CCS) polymers, can be envisaged as permanently cross-linked block copolymer micelles and, as such, afford novel opportunities for chemical functionalization, templating, and encapsulation. In this study, we explore the behavior of CSMG nanoparticles comprising a poly(methyl methacrylate) (PMMA) shell in molten PMMA thin films. Because of the autophobicity between the densely packed, short PMMA arms of the CSMG shell and the long PMMA chains in the matrix, the nanoparticles migrate to the film surface. They cannot, however, break through the surface because of the inherently high surface energy of PMMA. Similar thermal treatment of CSMG-containing PMMA thin films with a polystyrene (PS) capping layer replaces surface energy at the PMMA/air interface by interfacial energy at the PMMA/PS interface, which reduces the energy barrier by an order of magnitude, thereby permitting the nanoparticles to emerge out of the PMMA bulk. This nanoscale process is reversible and can be captured at intermediate degrees of completion. Moreover, it is fundamentally general and can be exploited as an alternative means by which to reversibly pattern or functionalize polymer surfaces for applications requiring responsive nanolithography.

Application of assessing care of vulnerable elders-3 quality indicators to patients with advanced dementia and poor prognosis.

OBJECTIVES: To use a formal decision-making strategy to reach clinically appropriate, internally consistent decisions on the application of quality indicators (QIs) to vulnerable elders (VEs) with advanced dementia (AD) or poor prognosis (PP). DESIGN: Using a conceptual model that classifies QIs principally by aim and burden of the care process, 12 clinical experts rated whether each Assessing Care of Vulnerable Elders-3 (ACOVE-3) QI should be applied in evaluating quality of care for older persons with AD or PP. QI exclusions were assessed for each of the 26 conditions and by whether these conditions were mainly medical (e.g., diabetes mellitus), geriatric (e.g., falls), or crosscutting processes of care (e.g., pain management). QI exclusions were also identified for older persons who decided against hospitalization or surgery. RESULTS: Of 392 ACOVE-3 QIs, 140 (36%) were excluded for patients with AD and 135 (34%) for patients with PP; 57% of QIs focusing on medical conditions were excluded from patients with AD and 53% from patients with PP, whereas only 20% of QIs for geriatric conditions were excluded from AD and 15% from PP. All QIs with care processes judged to carry a heavy burden were excluded; 86% of moderate-burden QIs were excluded from AD and 92% from PP. All QIs aimed at long-term goals were excluded; 83% of intermediate-term goal QIs were excluded from AD and 98% from PP. Individuals holding a preference to forgo hospitalization or surgery would be excluded from 7% of potentially applicable QIs. CONCLUSION: Measurement of quality of care for VEs with AD, PP, and less-aggressive care preferences should include only a subset of the ACOVE-3 QIs, largely those whose burden is light and whose goal is continuity or short-term improvement or prevention.

Multimorbidity is associated with better quality of care among vulnerable elders.

BACKGROUND: Older patients with multiple chronic conditions may be at higher risk of receiving poorer overall quality of care compared with those with single or no chronic conditions. Possible reasons include competing guidelines for individual conditions, burden of numerous recommendations, and difficulty implementing treatments for multiple conditions. OBJECTIVES: We sought to determine whether coexisting combinations of 8 common chronic conditions (hypertension, coronary artery disease, chronic obstructive pulmonary disease, osteoarthritis, diabetes mellitus, depression, osteoporosis, and having atrial fibrillation or congestive heart failure) are associated with overall quality of care among vulnerable older patients. MATERIALS AND METHODS: Using an observational cohort study, we enrolled 372 community-dwelling persons 65 years of age or older who were at increased risk for death or functional decline within 2 years. We included (1) a comprehensive measure (% of quality indicators satisfied) of quality of medical and geriatric care that accounted for patient preference and appropriateness in light of limited life expectancy and advanced dementia, and (2) a measure of multimorbidity, either as a simple count of conditions or as a combination of specific conditions. RESULTS: : Multimorbidity was associated with greater overall quality scores: mean proportion of quality indicators satisfied increased from 47% for elders with none of the prespecified conditions to 59% for those with 5 or 6 conditions (P < 0.0001), after controlling for number of office visits. Patients with greater multimorbidity also received care that was better than would be expected based on the specific set of quality indicators they triggered. CONCLUSIONS: Among older persons at increased risk of death or functional decline, multimorbidity results in better, rather than worse, quality of care.

The effect of a quality improvement initiative on the quality of other aspects of health care: the law of unintended consequences?

PROBLEM: Policymakers and clinicians are concerned that initiatives to improve the quality of care for some conditions may have unintended negative consequences for quality in other conditions. OBJECTIVE: We sought to determine whether a practice redesign intervention that improved care for falls, incontinence, and cognitive impairment by an absolute 15% change also affected quality of care for masked conditions (conditions not targeted by the intervention). DESIGN, SETTING, AND PARTICIPANTS: Controlled trial in 2 community medical groups, with 357 intervention and 287 control patients age 75 years or older who had difficulty with falls, incontinence, or cognitive impairment. INTERVENTION: Both intervention and control practices implemented case-finding for target conditions, but only intervention practices received a multicomponent practice-change intervention. Quality of care in the intervention practices improved for 2 of the target conditions (falls and incontinence). MAIN OUTCOME MEASURES: Percent of quality indicators satisfied for a set of 9 masked conditions measured by abstraction of medical records. RESULTS: Before the intervention, the overall percent of masked indicators satisfied was 69% in the intervention group and 67% in the control group. During the intervention period, these percentages did not change, and there was no difference between intervention and control groups for the change in quality between the 2 periods (P=0.86). The intervention minus control difference-in-change for the percent of masked indicators satisfied was 0.2% (bootstrapped 95% confidence interval, -2.7% to 2.9%). Subgroup analyses by clinical condition and by type of care process performed by the clinician did not show consistent results favoring either the intervention or the control group. CONCLUSION: A practice-based intervention that improved quality of care for targeted conditions by an absolute 15% change did not affect measurable aspects of care on a broad set of masked quality measures encompassing 9 other conditions.

Patients' global ratings of their health care are not associated with the technical quality of their care.

BACKGROUND: Patient global ratings of care are commonly used to assess health care. However, the extent to which these assessments of care are related to the technical quality of care received is not well understood. OBJECTIVE: To investigate the relationship between patient-reported global ratings of health care and the quality of providers' communication and technical quality of care. DESIGN: Observational cohort study. SETTING: 2 managed care organizations. PATIENTS: Vulnerable older patients identified by brief interviews of a random sample of community-dwelling adults 65 years of age or older who received care in 2 managed care organizations during a 13-month period. MEASUREMENTS: Survey questions from the second stage of the Consumer Assessment of Healthcare Providers and Systems program were used to determine patients' global rating of health care and provider communication. A set of 236 quality indicators, defined by the Assessing Care of Vulnerable Elders project, were used to measure technical quality of care given for 22 clinical conditions; 207 quality indicators were evaluated by using data from chart abstraction or patient interview. RESULTS: Data on the global rating item, communication scale, and technical quality of care score were available for 236 vulnerable older patients. In a multivariate logistic regression model that included patient and clinical factors, better communication was associated with higher global ratings of health care. Technical quality of care was not significantly associated with the global rating of care. LIMITATIONS: Findings were limited to vulnerable elders who were enrolled in managed care organizations and may not be generalizable to other age groups or types of insurance coverage. CONCLUSIONS: Vulnerable elders' global ratings of care should not be used as a marker of technical quality of care. Assessments of quality of care should include both patient evaluations and independent assessments of technical quality.

Comparison of administrative data and medical records to measure the quality of medical care provided to vulnerable older patients.

BACKGROUND: Administrative data are used to determine performance for publicly reported in health plan "report cards," accreditation status, and reimbursement. However, it is unclear how performance based on administrative data and medical records compare. METHODS: We compared applicability, eligibility, and performance on 182 measures of health care quality using medical records and administrative data during a 13-month period for a random sample of 399 vulnerable older patients enrolled in managed care. RESULTS: Of 182 quality indicators (QIs) spanning 22 conditions, 145 (80%) were applicable only to medical records and 37 (20%) to either medical records or administrative data. Among 48 QIs specific to geriatric conditions, all were applicable to medical records; 2 of these also were applicable to administrative data. Eligibility for the 37 QIs that were applicable to both medical records and administrative data was similar for both data sources (94% agreement, kappa = 0.74). With the use of medical records, 152 of the 182 the QIs that were applicable to medical records were triggered and yielded an overall performance of 55%. Using administrative data, 30 of the 37 QIs that were applicable to administrative data were triggered and yielded overall performance of 83% (P < 0.05 vs. medical records). Restricting to QIs applicable to both data sources, overall performance was 84% and 83% (P = 0.21) for medical records and administrative data, respectively. CONCLUSIONS: The number and spectrum of QIs that can be measured for vulnerable elderly patients is far greater for medical records than for administrative data. Although summary estimates of health care quality derived from administrative data and medical records do not differ when using identical measures, summary scores from these data sources vary substantially when the totality of care that can be measured by each data source is measured.

Do proxies reflect patients' health concerns about urinary incontinence and gait problems?

BACKGROUND: While falls and urinary incontinence are prevalent among older patients, who sometimes rely on proxies to provide their health information, the validity of proxy reports of concern about falls and urinary incontinence remains unknown. METHODS: Telephone interviews with 43 consecutive patients with falls or fear of falling and/or bothersome urinary incontinence and their proxies chosen by patients as most knowledgeable about their health. The questionnaire included items derived from the Medical Outcomes Study Short Form 12 (SF-12), a scale assessing concerns about urinary incontinence (UI), and a measure of fear of falling, the Falls Efficacy Scale (FES). Scores were estimated using items asking the proxy perspective (6 items from the SF-12, 10 items from a UI scale, and all 10 FES items). Proxy and patient scores were compared using intraclass correlation coefficients (ICC, one-way model). Variables associated with absolute agreement between patients and proxies were explored. RESULTS: Patients had a mean age of 81 years (range 75-93) and 67% were female while proxies had a mean age of 70 (range 42-87) and 49% were female. ICCs were 0.63 for the SF-12, 0.52 for the UI scale, and 0.29 for the FES. Proxies tended to understate patients' general health and incontinence concern, but overstate patients' concern about falling. Proxies who lived with patients and those who more often see patients more closely reflected patient FES scores compared to those who lived apart or those who saw patients less often. Internal consistency reliability of proxy responses was 0.62 for the SF-12, 0.86 for the I-QOL, and 0.93 for the FES. In addition, construct validity of the proxy FES scale was supported by greater proxy-perceived fear of falling for patients who received medical care after a fall during the past 12 months (p < .05). CONCLUSION: Caution should be exercised when using proxies as a source of information about older patients' health perceptions. Questions asking about proxies' views yield suboptimal agreement with patient responses. However, proxy scales of UI and fall concern are internally consistent and may provide valid independent information.

Predictors of overall quality of care provided to vulnerable older people.

OBJECTIVES: Prior research shows that the quality of care provided to vulnerable older persons is suboptimal, but little is known about the factors associated with care quality for this group. In this study, the influences of clinical conditions, types of care processes, and sociodemographic characteristics on the quality of care received by vulnerable older people were evaluated. DESIGN: Observational cohort study. SETTING: Two senior managed care plans. PARTICIPANTS: Three hundred sixty-two community-dwelling patients aged 65 and older identified as vulnerable by the Vulnerable Elder Survey (VES-13). OUTCOME VARIABLE: patients' observed-minus-expected overall quality score. PREDICTOR VARIABLES: types of care processes, types and number of clinical conditions, sex, age, VES-13 score (composite score of function and self-rated health), income, education, mental health status, and number of quality indicators triggered. RESULTS: Patients whose conditions required more history-taking, counseling, and medication-prescribing care processes and patients with diabetes mellitus received lower-than-expected quality of care. A greater number of comorbid conditions was associated with higher-than-expected quality of care. Age, sex, VES-13 score, and other sociodemographic variables were not associated with quality of care. CONCLUSION: Complexity, vulnerability, and age do not predispose older persons to receive poorer-quality care. In contrast, older patients whose care requires time-consuming processes such as history taking and counseling are at risk for worse quality of care and should be a target for intervention to improve care.

Quality of care is associated with survival in vulnerable older patients.

BACKGROUND: Although assessment of the quality of medical care often relies on measures of process of care, the linkage between performance of these process measures during usual clinical care and subsequent patient outcomes is unclear. OBJECTIVE: To examine the link between the quality of care that patients received and their survival. DESIGN: Observational cohort study. SETTING: Two managed care organizations. PATIENTS: Community-dwelling high-risk patients 65 years of age or older who were continuously enrolled in the managed care organizations from 1 July 1998 to 31 July 1999. MEASUREMENTS: Quality of care received by patients (as measured by a set of quality indicators covering 22 clinical conditions) and their survival over the following 3 years. RESULTS: The 372 vulnerable older patients were eligible for a mean of 21 quality indicators (range, 8 to 54) and received, on average, 53% of the care processes prescribed in quality indicators (range, 27% to 88%). Eighty-six (23%) persons died during the 3-year follow-up. There was a graded positive relationship between quality score and 3-year survival. After adjustment for sex, health status, and health service use, quality score was not associated with mortality for the first 500 days, but a higher quality score was associated with lower mortality after 500 days (hazard ratio, 0.64 [95% CI, 0.49 to 0.84] for a 10% higher quality score). LIMITATIONS: The observational design limits causal inference regarding the effect of quality of care on survival. CONCLUSIONS: Better performance on process quality measures is strongly associated with better survival among community-dwelling vulnerable older adults.

Geriatrics for residents in the surgical and medical specialties: implementation of curricula and training experiences.

In 1994, under the leadership of the late Dennis Jahnigen, the American Geriatrics Society, with support of the John A. Hartford Foundation, began a project to improve the amount and quality of geriatrics education that surgical and related medical specialty residents receive. The targeted disciplines initially were general surgery, emergency medicine, gynecology, orthopedic surgery, and urology and, later, anesthesiology, ophthalmology, otolaryngology, physical medicine and rehabilitation, and thoracic surgery. A key element of this project was to develop model programs within surgical and related specialty residency education. The Geriatrics Education for Specialty Residents (GESR) program has supported 29 residencies to pilot methods for integration of geriatrics within residency programs, encouraged and inspired development of curricular content, and helped to develop faculty leaders to support these efforts in the long term and at a national level. This paper describes the GESR program, the status of curriculum development, steps for other programs to use in developing a geriatrics education program, and some of the common barriers likely to be encountered during implementation along with solutions to those barriers.