Single molecule conductance of biological building blocks purines and imidazole

In the last decade, biological molecules such as Deoxyribonucleic acid (DNA) and some proteins have attracted attention as material candidates for molecular electronics applications. Yet, despite numerous studies of electron transport in DNA in particular, inconsistencies in experimental results persist. As a result, both the degree and mechanism of charge transport in these biological molecules remain disputed. To understand if different binding configurations of DNA on metal electrodes through unexpected moieties could be responsible for experimental inconsistencies in the literature, we investigate whether small molecules ubiquitous in both nucleic acids and amino acids, such as purines and imidazole, bind to gold electrodes and produce conductance signature. In this study, we use the Scanning Probe Microscope-based Break Junctions approach method to study single molecule conductance and binding geometry of the purine bases of DNA, particularly adenine and guanine. In addition, the Conductive Atomic Force Microscope-based Break Junction (CAFMBJ) platform has been created to simultaneously measure both electrical and mechanical properties of these single molecule junctions. Our measurements indicate that purines bind in the junction and display several robust conductance signatures on gold. We find that both purine and adenine bind through the imidazole, which is identified, for the first time, as a new linker group for single molecule conductance measurements

Local Defects in colloidal quantum dot thin films measured via spatially resolved multi-modal optoelectronic spectroscopy.

The morphology, chemical composition, and electronic uniformity of thin-film solution-processed optoelectronics are believed to greatly affect device performance. Although scanning probe microscopies can address variations on the micrometer scale, the field of view is still limited to well under the typical device area, as well as the size of extrinsic defects introduced during fabrication. Herein, a micrometer-resolution 2D characterization method with millimeter-scale field of view is demonstrated, which simultaneously collects photoluminescence spectra, photocurrent transients, and photovoltage transients. This high-resolution morphology mapping is used to quantify the distribution and strength of the local optoelectronic property variations in colloidal quantum dot solar cells due to film defects, physical damage, and contaminants across nearly the entire test device area, and the extent to which these variations account for overall performance losses. It is found that macroscopic defects have effects that are confined to their localized areas, rarely prove fatal for device performance, and are largely not responsible for device shunting. Moreover, quantitative analysis based on statistical partitioning methods of such data is used to show how defect identification can be automated while identifying variations in underlying properties such as mobilities and recombination strengths and the mechanisms by which they govern device behavior.DMR-1807342 - National Science Foundation; Hopkins Extreme Materials InstituteAccepted manuscrip

Depression treatment patterns among individuals with osteoarthritis: a cross sectional study

BACKGROUND: Arthritis and depression often co-occur; however, studies that describe patterns of depression treatment among individuals with arthritis are scant. The purpose of the study was to examine depression treatment patterns among individuals with osteoarthritis (OA) by predisposing, enabling, need factors, personal health practices and external health environment. METHODS: Retrospective cross-sectional design was used. Data were obtained from 2008 and 2010 Medical Expenditure Panel Survey (MEPS). The sample consisted of 647adults aged over 21 years with depression and OA. Depression treatment was categorized as: 1) No treatment;2) antidepressant use only and 3) both antidepressants and psychotherapy (combination therapy). Chi- square tests and multinomial logistic regressions were used to describe patterns of depression treatment. All analysis was performed using Statistical Analysis Software (SAS) version 9.3. RESULTS: Overall, 13.0% of the study sample reported no depression treatment, 67.8% used antidepressants only and 19.2% used combination therapy. Among individuals with OA significant subgroup differences in depression treatment were observed. For example, African Americans were less likely to report depression treatment compared to whites [antidepressants: AOR=0.33, 95% CI=0.21,0.51; combination therapy: AOR=0.39, 95% CI=0.23, 0.65]. Elderly adults were more likely to receive antidepressants and less likely to receive psychotherapy as compared to younger adults [AOR=0.53, 95% CI= 0.28,0.98]. Adults with anxiety were more likely to report depression treatment compared to those without anxiety [antidepressants: AOR=1.53, 95% CI=1.06, 2.22; combination therapy: AOR=3.52, 95% CI=2.40, 5.15]. CONCLUSION: Future research needs to examine the reason for low rates of combination therapy as well as subgroup differences in combination therapy among individuals with OA

Depression treatment patterns among individuals with osteoarthritis: a cross sectional study

Background Arthritis and depression often co-occur; however, studies that describe patterns of depression treatment among individuals with arthritis are scant. The purpose of the study was to examine depression treatment patterns among individuals with osteoarthritis (OA) by predisposing, enabling, need factors, personal health practices and external health environment. Methods Retrospective cross-sectional design was used. Data were obtained from 2008 and 2010 Medical Expenditure Panel Survey (MEPS). The sample consisted of 647adults aged over 21 years with depression and OA. Depression treatment was categorized as: 1) No treatment;2) antidepressant use only and 3) both antidepressants and psychotherapy (combination therapy). Chi- square tests and multinomial logistic regressions were used to describe patterns of depression treatment. All analysis was performed using Statistical Analysis Software (SAS) version 9.3. Results Overall, 13.0% of the study sample reported no depression treatment, 67.8% used antidepressants only and 19.2% used combination therapy. Among individuals with OA significant subgroup differences in depression treatment were observed. For example, African Americans were less likely to report depression treatment compared to whites [antidepressants: AOR=0.33, 95% CI=0.21,0.51; combination therapy: AOR=0.39, 95% CI=0.23, 0.65]. Elderly adults were more likely to receive antidepressants and less likely to receive psychotherapy as compared to younger adults [AOR=0.53, 95% CI= 0.28,0.98]. Adults with anxiety were more likely to report depression treatment compared to those without anxiety [antidepressants: AOR=1.53, 95% CI=1.06, 2.22; combination therapy: AOR=3.52, 95% CI=2.40, 5.15]. Conclusion Future research needs to examine the reason for low rates of combination therapy as well as subgroup differences in combination therapy among individuals with OA

Inhaled anticholinergic use and all-cause mortality among elderly Medicare beneficiaries with chronic obstructive pulmonary disease

Background: The purpose of this study was to examine the association between use of inhaled anticholinergics and all-cause mortality among elderly individuals with chronic obstructive pulmonary disease (COPD), after controlling for demographic, socioeconomic, health, functional status, smoking, and obesity.Methods: We used a retrospective longitudinal panel data design. Data were extracted for multiple years (2002–2009) of the Medicare Current Beneficiary Survey (MCBS) linked with fee-for-service Medicare claims. Generic and brand names of inhaled anticholinergics were used to identify inhaled anticholinergic utilization from the self-reported prescription medication files. All-cause mortality was assessed using the vital status variable. Unadjusted group differences in mortality rates were tested using the chi-square statistic. Multivariable logistic regressions with independent variables entered in separate blocks were used to analyze the association between inhaled anticholinergic use and all-cause mortality. All analyses accounted for the complex design of the MCBS.Results: Overall, 19.4% of the elderly Medicare beneficiaries used inhaled anticholinergics. Inhaled anticholinergic use was significantly higher (28.5%) among those who reported poor health compared with those reporting excellent or very good health (12.7%). Bivariate analyses indicated that inhaled anticholinergic use was associated with significantly higher rates of all-cause mortality (18.7%) compared with nonusers (13.6%). However, multivariate analyses controlling for risk factors did not suggest an increased likelihood of all-cause mortality (adjusted odds ratio 1.26, 95% confidence interval 0.95–1.67).Conclusion: Use of inhaled anticholinergics among elderly individuals with COPD is potentially safe in terms of all-cause mortality when we adjust for baseline risk factors

Association between Metformin Use and Cancer Stage at Diagnosis among Elderly Medicare Beneficiaries with Preexisting Type 2 Diabetes Mellitus and Incident Prostate Cancer

Objective. To examine the association between metformin use and cancer stage at diagnosis among elderly men with preexisting diabetes mellitus and incident prostate cancer. Methods. This study used a population-based observational cohort of elderly men (≥66 years) with preexisting diabetes and incident prostate cancer between 2008 and 2009 ( = 2, 652). Cancer stage at diagnosis (localized versus advanced) was based on the American Joint Cancer Committee classification. Metformin use and other independent variables were measured during the one year before cancer diagnosis. Logistic regressions with inverse probability treatment weights were used to control for the observed selection bias. Results. A significantly lower percentage of metformin users were diagnosed with advanced prostate cancer as compared to nonusers (4.7% versus 6.7%, \u3c 0.03). After adjusting for the observed selection bias and other independent variables, metformin use was associated with a 32% reduction in the risk of advanced prostate cancer (adjusted odds ratio, AOR: 0.68, 95% confidence interval, CI: 0.48, 0.97). Conclusions. This is the first epidemiological study to support the role of metformin in reducing the risk of advanced prostate cancer. Randomized clinical trials are needed to confirm the causal link between metformin use and prostate cancer diagnosis stage

Detection of Novel Variations Related to Litter Size in BMP15 Gene of Luzhong Mutton Sheep ( Ovis aries )

SIMPLE SUMMARY: BMP15 is a critical gene in sheep reproduction. Most of its variations have been reported in European sheep. In this study, the entire open reading frame (ORF) region of BMP15 was sequenced in 154 Luzhong mutton sheep. Among 13 identified variations, six were novel. Four SNPs (ENSOART00000010201.1:c.352+342C>A, c.352+1232T>C, c.352+1165A>G and c.353-2036T>A) were significantly associated with litter size, and could be used as candidate genetic markers for improving litter size. The results also suggested possible interaction between BMP15 and FecB/GDF9. ABSTRACT: Litter size is an important economic trait in the mutton sheep industry. BMP15 is one of the key candidate genes for litter size in sheep. In this study, the entire ORF region of BMP15 was sequenced in 154 Luzhong mutton ewes, and the novel variations were determined. The association between polymorphism in BMP15 and litter size was analyzed using a general linear model. Six out of a total of thirteen variations were identified to be novel. Association analysis indicated that four (SNPs ENSOART00000010201.1:c.352+342C>A, c.352+1232T>C, c.352+1165A>G and c.353-2036T>A) were significantly associated with litter size. The joint analysis among three major genes (BMP15, BMPR1B and GDF9) exhibited significant interaction effects in three combinations (FecB and c.352+1232T>C of BMP15; FecB and c.352+1165A>G of BMP15; c.352+342C>A of BMP15 and ENSOART00000014382.1:c.994G>A of GDF9). For the SNPs c.352+1232T>C and c.352+342C>A, the global distribution of allele frequencies showed that the highest variation frequency occurs in Western Europe. In conclusion, the results demonstrated that BMP15 is a major gene for litter size in Luzhong mutton sheep and candidate SNPs associated with litter size were identified