Picosecond Switchable Azo Dyes.

Azo dyes that combine electron-withdrawing thiazole/benzothiazole heterocycles and electron-donating amino groups within the very same covalent skeleton exhibit relaxation times for their thermal isomerization kinetics within milli- and microsecond timescales at room temperature. Notably, the thermal back reaction of the corresponding benzothiazolium and thiazolium salts occurred much faster, within the picosecond temporal domain. In fact, these new light-sensitive platforms are the first molecular azo derivatives capable of reversible switching between their trans and cis isomers in a subnanosecond timescale under ambient conditions. In addition, theoretical calculations revealed very low activation energies for the isomerization process, in accordance with the fast subnanosecond kinetics that were observed experimentally.

Solid-state organization of n-type carbazole-based semiconductors for organic thin-film transistors.

The development of new organic semiconductors has been mainly led by the search for new π-conjugated cores, but recently the use of flexible side chains is attracting more and more attention to control the molecular packing and order in the solid state to improve the charge-transporting properties. In this work, the charge transport properties of a series of tricyanovinyl-substituted carbazole-based materials with different alkyl chain lengths have been investigated and correlated with the respective intermolecular interactions and molecular packings via X-ray diffraction (XRD) studies.

Interface engineering and solid-state organization for triindole-based p-type organic thin-film transistors.

Inspired by the excellent device performance of triindole-based semiconductors in electronic and optoelectronic devices, the relationship between the solid-state organization and the charge-transporting properties of an easily accessible series of triindole derivatives is reported herein. The vacuum-evaporated organic thin-film transistors (OTFTs) exhibited a non ideal behaviour with a double slope in the saturation curves. Moreover, the treatment of the gate insulator of the OTFT device with either a self-assembled monolayer (SAM) or a polymer controls the molecular growth and the film morphology of the semiconducting layer, as shown by X-ray diffraction (XRD) analyses, atomic force microscopy (AFM) and theoretical calculations. N-Trihexyltriindole exhibited the best device performance with hole mobilities up to 0.1 cm2 V-1 s-1 at the low VG range and up to 0.01 cm2 V-1 s-1 at high VG, as well as enhanced Ion/Ioff ratios of around 106. The results suggest that the non-ideal behaviour of the here studied OTFT devices could be related to the higher interfacial disorder in comparison to that in the bulk.

Tuning the ambipolar charge transport properties of tricyanovinyl-substituted carbazole-based materials.

A series of push-pull carbazole-based compounds has been experimentally and theoretically characterized in combination with the X-ray analysis of the corresponding single crystals. The introduction of the strong electron-withdrawing tricyanovinyl group in the carbazole core affords electron-transporting ability in addition to the characteristic hole-transporting properties exhibited by donor carbazole derivatives.

Stable All-Organic Radicals with Ambipolar Charge Transport.

A series of neutral long-lived purely organic radicals based on the stable [4-(N-carbazolyl)-2,6-dichlorophenyl]bis(2,4,6-trichlorophenyl)methyl radical adduct (Cbz-TTM) is reported herein. All compounds exhibit ambipolar charge-transport properties under ambient conditions owing to their radical character. High electron and hole mobilities up to 10-2 and 10-3  cm2 V-1 s-1 , respectively, were achieved. Xerographic single-layered photoreceptors were fabricated from the radicals studied herein, exhibiting good xerographic photosensitivity across the visible spectrum.

Spatially close azo dyes with sub-nanosecond switching speeds and exceptional temporal resolution.

Photoswitchable bis-azo dyes with an outstanding temporal resolution of 10(15) times between the thermal relaxation rates of their two constituting photochromes are reported. Remarkably, the close spatial proximity of both azo photochromes in these molecular assemblies translates in an unprecedented 10(3) -fold acceleration of the thermal isomerization rate of their faster azo unit compared to the one displayed by the isolated counterpart. Indeed, the relaxation time of the fast-isomerizing platform of the herein reported bis-azobenzenes is as low as 200 ps under ambient conditions. In the wake of these results, the bis-azo dyes described herein are invaluable chromophores for the design of multifunctional light-addressable materials in which simultaneous switching in two very different timescales might be essential.

Charge transfer states in stable neutral and oxidized radical adducts from carbazole derivatives.

In this paper we report the spectral properties of the stable radical adducts 1(•)-3(•), which are formed by an electron donor moiety, the carbazole ring, and an electron acceptor moiety, the polychlorotriphenylmethyl radical. The molecular structure of radical adduct 1(•) in the crystalline state shows a torsion angle of approximately 90° between the phenyl and the carbazole rings due to steric interactions. They exhibit a charge transfer band in the visible range of the electronic spectrum. All of them are chemically oxidized with copper(II) perchlorate to the respective cation species, which show a strong charge transfer band into the near-infrared region of the spectrum. Radical adducts 1(•)-3(•) and the corresponding stable oxidized species 1(+)-3(+) are real organic mixed-valence compounds due to the open-shell nature of their electronic structure. Charge transfer bands of the cation species are stronger and are bathochromically shifted with respect to those of the neutral species due to the greater acceptor ability of the positively charged central carbon atom of the triphenylmethyl moiety. The cationic species 1(+)-3(+) are diamagnetic, as shown by the absence of a signal in the EPR spectrum in acetonitrile solution at room temperature, but they show an intense and unique band in frozen solutions (183 K).

Oxidative stress and exceptional human longevity: Systematic review.

OBJECTIVE: Oxidative stress (OS) has been previously linked to the aging process, as have some diseases and geriatric syndromes as frailty and sarcopenia. The aim of the present study was to perform a systematic review on oxidative stress activity and extreme longevity in humans. METHODS: We conducted a systematic literature review following the PRISMA guidelines. Observational studies assessing OS-biomarkers and/or antioxidants in long-lived individuals (97 years old or over) comparing them to those of one or more age groups, (at least one of which from comprising elderly subjects) were considered for inclusion. A narrative synthesis was planned. Quality of selected studies was assessed using the Newcastle-Ottawa quality assessment scale (NOS). RESULTS: After screening and eligibility phases, 12 articles were finally selected, with 646 long-lived participants and 1052 controls, 447 adults (20-60 years old) and 605 elderly individuals (over 60 years old). The average score on NOS scale of studies was 4,8 out of 9. Centenarians showed significantly less (p<0,05) oxidative damage to lipids in different samples, lower levels of oxidized proteins in plasma and lower superoxide anion levels in neutrophils than elderly groups. Centenarian presented significantly lower superoxide dismutase and higher glutathione reductase activities, higher levels of vitamins A and E, lower of coenzyme Q10, and lower susceptibility to lipid peroxidation than elderly controls. CONCLUSION: Based on studies of medium-low quality, available evidence suggests that long-lived individuals display less oxidative damage, particularly lower plasma lipid peroxidation biomarkers, than controls. More studies with better experimental designs are needed.

Frailty, Polypharmacy, and Health Outcomes in Older Adults: The Frailty and Dependence in Albacete Study.

BACKGROUND/OBJECTIVES: To investigate if polypharmacy modifies the association between frailty and health outcomes in older adults. DESIGN: Ongoing cohort study. SETTING: Albacete City, Spain. PARTICIPANTS: A total for 773 participants, 457 women (59.1%), over age 70 years from the FRADEA Study. MEASUREMENTS: Frailty phenotype, polypharmacy considered as the chronic use of 5 or more drugs, and comorbidity were collected at the baseline visit. Participants were categorized in 6 groups according to frailty and polypharmacy, and were followed up for 5.5 years (mean 1057 days, range 1-2007). Mortality or incident disability in basic activities of daily living was considered the main outcome variable. Hospitalization and visits to the emergency department were also recorded. The adjusted association between combined frailty status and polypharmacy with outcome variables was analyzed. RESULTS: The mean age of study population was 78.5 years. In this population, we identified a 15.3% (n = 118) of frail with polypharmacy, 3.4% (n = 26) of frail without polypharmacy, 35.3% (n = 273) of prefrail with polypharmacy, 20.3% (n = 157) of prefrail without polypharmacy, 10.3% (n = 80) of nonfrail with polypharmacy, and 15.4% (n = 119) of nonfrail participants without polypharmacy. Participants with frailty and polypharmacy had a higher adjusted risk of mortality or incident disability [odds ratio (OR) 5.3; 95% confidence interval (CI) 2.3-12.5] and hospitalization (OR 2.3; 95% CI 1.2-4.4), compared with those without frailty and polypharmacy. Frail and prefrail participants with polypharmacy had a higher adjusted mortality risk compared with the nonfrail without polypharmacy, hazard ratio 5.8 (95% CI 1.9-17.5) and hazard ratio 3.1 (95% CI 1.1-9.1), respectively. CONCLUSIONS: Polypharmacy is associated with mortality, incident disability, hospitalization, and emergency department visits in frail and prefrail older adults, but not in nonfrail adults. Polypharmacy should be monitored in these patient subgroups to optimize health outcomes.

Use of health resources and healthcare costs associated with nutritional risk: The FRADEA study.

BACKGROUND: In spite of its high prevalence and its clinical relevance, the economic impact of malnutrition has not been sufficiently explored. OBJECTIVE: To study whether malnutrition predicts total hospital healthcare costs and costs related to specialist visits, emergency department visits and hospitalization in older adults. METHODS: Concurrent cohort study in Albacete City, Spain. The study sample included 827 subjects aged 70 and over from the FRADEA Study. Mini Nutritional Assessment®-Short Form (MNA®-SF) was recorded at baseline. Use of hospital resources (hospital admissions, emergency visits, and specialist visits), and hospital healthcare costs were recorded at follow-up. Generalized linear models (GLM) adjusted for age, sex, comorbidity, polypharmacy, and disability in basic activities of daily living were used to estimate the impact of nutritional factors on total healthcare costs per person/year (€ base year 2013) as well as specialist visit costs, emergency department visit costs and hospitalization costs. RESULTS: The average cost associated with the use of health resources was 1922€/year. Subjects with MNA®-SF between 0 and 7 had an average total health cost of 3492€/year, 2744€/year in those with MNA®-SF between 8 and 11, and 1542€/year in those with MNA®-SF between 12 and 14. Of the total health cost, 67.2% was associated with hospital admission costs. Adjusted healthcare costs were 714€/year greater in subjects with malnutrition or nutritional risk. Subjects with malnutrition or nutritional risk presented an increased adjusted risk of hospitalization (OR1.72, 95% CI 1.22-2.43). CONCLUSIONS: Malnutrition assessed by MNA®-SF is a prognostic factor of high healthcare cost and use of resources in older adults.

Benefits of a multicomponent Falls Unit-based exercise program in older adults with falls in real life.

BACKGROUND/OBJECTIVES: Multicomponent exercise programs are the cornerstone in preventing gait and balance impairments and falls in older adults. However, the effects of these programs in usual clinical practice have been poorly analyzed. DESIGN: 4-Month, twice-a-week multicomponent exercise program cohort study in real-life. SETTING: Falls Unit, Complejo Hospitalario Universitario of Albacete, Spain. PARTICIPANTS: Sixty-seven participants who had experienced a fall in the previous year were included. MEASUREMENTS: Pre- and post-intervention measurements were collected for leg press, gait speed, the Short Physical Performance Battery (SPPB), the Falls Efficiency Scale International, fat mass percentage, body mass index, the Geriatric Depression Scale by Yesavage (GDS), the Mini Mental State Examination, and the number of falls. RESULTS: Fifty participants completed the program (adherence rate 75%, attendance 80%). Their mean age was 77.2 (SD 5.8) years; 39 were women. The participants reduced the mean number of frailty criteria from 2.1 to 1.3 (95%CI 0.4-1.1) and increased mean gait speed from 0.65 m/s to 0.82 m/s (95%CI 0.11-0.22), increasing their median SPPB scores from 8.5 to 10.0 points (p < 0.001), leg press strength from 62.5 kg to 80.0 kg (p < 0.001), and leg press power at 60% load from 76 W to 119 W (p < 0.001). There was also an improvement in GDS scores from 5.3 to 4.4 (95%CI 0.1-1.7). Body mass index did not change, but fat-free mass increased from 43.7 kg to 44.2 kg (95%CI 0.1-1.0), and fat mass percentage declined from 36.7% to 36.0% (95% CI 0.1-1.4). Seventeen patients (34%) had a fall during the six-month follow-up, and there was a reduction in the median number of falls from 3.0/year to 0.0/six months. CONCLUSIONS: A multicomponent Falls Unit-based exercise program as part of usual clinical practice in real life, improved physical function, reduced depressive symptoms, improved body composition and decreased the number of falls in older adults with previous falls.

[Rationale, design and methodology of physical attributes identification of the fear of falling syndrome (FISTAC study)]. / Razonamiento, diseño y metodología del estudio de identificación de los atributos físicos del síndrome de temor a caerse en ancianos (FISTAC).

INTRODUCTION: The aim of this study was to identify the physical determining factors of the Fear of Falling Syndrome (FoF) in older adults with a history of falls. METHODS: An observational study was conducted on 183 subjects older than 64 years with a fall in the previous year, with data collected from the geriatrics outpatient clinic of the Complejo Hospitalario Universitario from Albacete, Spain. Sociodemographic and anthropometric data, as well as comorbidity, drugs usually taken, functional status, physical function, frailty, cognitive and affective status were collected. Muscle mass was measured using bioimpedancy meter (BIA), and densitometry (DXA), strength with digital hand-held JAMAR dynamometer and with a Leg-press machine, muscle potency with a T-Force instrument, gait variability with the Gait-Rite instrument, and postural stability with the Neurocom Balance Master posturograph were also determined. An analysis was performed to determine if the FoF is associated with physical impairments adjusted for the study covariates. RESULTS: The study included 140 subjects with FoF, and 43 without it. The mean age was 78.4 years, and 147 were women. Posturography could be measured in 182 participants, DXA in 117, BIA in 165, and muscle potency in 146. FoF was associated with female sex, frailty, depressed mood, social risk, muscle strength and power, physical function, number of drugs used, and orthostatic hypotension in the overall sample. After adjusting for sex, only frailty, depressed mood, and number of drugs remained associated. CONCLUSIONS: Rationale, design, and methods of the FISTAC study are presented.

Potential early biomarkers of sarcopenia among independent older adults.

OBJECTIVES: There are no tools or biomarkers for a quantitative analysis of sarcopenia. STUDY DESIGN: Cross-sectional study of the diagnosis of sarcopenia in 200 independent adults aged 70 years or over. MAIN OUTCOME MEASURES: Sarcopenia was defined as loss of muscle mass together with low strength and/or loss of physical performance. We considered different clinical parameters and assayed potential blood biomarkers (cell energetic metabolism, muscle performance, inflammation, infection and oxidative stress). RESULTS: The prevalence of sarcopenia was 35.3% in women and 13.1% in men, and it was significantly associated with advanced age, a low functional performance in the lower extremities, deficient weekly consumption of kilocalories, risk of malnutrition, and drug use for the digestive system. A close relationship was found between sarcopenia, pre-frailty and depressed mood. With these confounding variables, we observed that products of lipid peroxidation were closely associated with sarcopenia in independent older adults (frail participants and those with severe dependence had been excluded from the sample). The best multivariate model proposed was able to predict 67.6% of the variance in sarcopenia, with a power of discrimination of 93.5%. Additional analyses considering lipid levels, fat mass, dyslipidemia, use of lipid-lowering drugs and hypertension confirmed this close association between lipid peroxidation and sarcopenia. CONCLUSIONS: Given the difficulty in the diagnosis of sarcopenia in clinical practice, we suggest the use of blood circulating products of lipid peroxidation as potential biomarkers for an early diagnosis of sarcopenia in independent older adults.

[Frailty and long term mortality, disability and hospitalisation in Spanish older adults. The FRADEA Study]. / Fragilidad como predictor de mortalidad, discapacidad incidente y hospitalización a largo plazo en ancianos españoles. Estudio FRADEA.

INTRODUCTION: The objective of this study was to analyse whether frailty is related to long-term mortality, incident disability in basic activities of daily living (BADL), and hospitalisation. MATERIAL AND METHODS: A concurrent cohort study conducted on 993 participants over age 70 from the FRADEA Study. Frailty was determined with Fried frailty phenotype. Data was collected on mortality, hospitalisation and incident disability in BADL (bathing, grooming, dressing, toileting, eating or transferring) during the follow-up period. The risk of adverse events was determined by logistic regression, Kaplan-Meier analysis, and Cox proportional hazard analysis adjusted for age, sex, Barthel index, comorbidity and institutionalization. RESULTS: Mean follow-up was 952 days (SD 408), during which 182 participants (18.4%) died. Frail participants had an increased adjusted risk of death (HR 4.5, 95%CI: 1.8-11.1), incident disability in BADL (OR 2.7, 95%CI: 1.3-5.9) and the combined event mortality or incident disability (OR 3.0, 95%CI: 1.5-6.1). Pre-frail subjects had an increased adjusted risk of death (HR 2.9, 95%CI: 1.2-6.5), incident disability in BADL (OR 2.1, 95%CI: 1.2-3.6), and the combined event mortality or incident disability (OR 2.2, 95%CI: 1.3-3.6). There was a positive association between frailty and hospitalisation, which almost reached statistical significance (OR 1.7, 95%CI: 1.0-3.0). CONCLUSIONS: Frailty is long-term associated with mortality and incident disability in BADL in a Spanish cohort of older adults.

A photoswitchable bis-azo derivative with a high temporal resolution.

The novel photoswitchable bis-azo derivative reported herein shows a high temporal resolution of 2 × 10(8) times between the thermal relaxation rates of its two constituting photochromes. Moreover, the slow and fast azo building blocks of this molecular construct can be triggered by using UV and visible light, respectively.

Molecular photo-oscillators based on highly accelerated heterocyclic azo dyes in nematic liquid crystals.

Benzothiazole-pyrrole-based azo dyes greatly enhance their thermal isomerisation rate by up to 160 times when they are under the influence of the nematic mean field yielding the LC-based photochromic oscillators with the highest oscillation frequencies reported so far (2.6 kHz at 298 K).

[Chronic disease, mortality and disability in an elderly Spanish population: the FRADEA study]. / Enfermedad crónica, mortalidad, discapacidad y pérdida de movilidad en ancianos españoles: estudio FRADEA.

INTRODUCTION: The objective of this study was to analyse the relationships between the major chronic diseases and multiple morbidity, with mortality, incident disability in basic activities of daily living, and loss of mobility in the elderly. MATERIAL AND METHODS: A total of 943 participants were selected from the FRADEA Study, using available baseline data of chronic diseases, and at the follow-up visit of mortality, incident disability, and loss of mobility. The analysis was made of the unadjusted and adjusted association between the number of chronic diseases, the number of 14 pre-selected diseases, and the presence of two or more chronic diseases (multiple morbidity) with adverse health events recorded. RESULTS: Participants with a higher number of diseases (OR 1.11; 95% CI: 1.02-1.22), and 14 pre-selected diseases (OR 1.19; 95% CI: 1.03-1.38) had a higher adjusted mortality risk, but not a higher incident disease or mobility loss risk. Subjects with multiple morbidity had a higher non-significant mortality risk (HR 1.45; 95% CI: 0.87-2.43), than those without multiple morbidity. Disability-free mean time in participants with and without multiple morbidity was 846±34 and 731±17 days, respectively (Log-rank χ(2) 7.45. P=.006), and with our without mobility loss was 818±32 and 696±13 days, respectively (Log rank χ(2) 10.99. P=.001). CONCLUSIONS: Multiple morbidity was not associated with mortality, incident disability in ADL, or mobility loss in adults older than 70 years, although if mortality is taken into account, the number of chronic diseases is linear.

Associations of the antioxidant capacity and hemoglobin levels with functional physical performance of the upper and lower body limbs.

Herein we considered the role of oxidative stress on deficiencies of functional physical performance that could affect a future pre-frailty condition. Using principal component analyses (PCA), we created new variables to better describe the functionality regarding the physical performance of the upper and lower body limbs. Gait speed and the Short Physical Performance Battery (SPPB) score were classified by PCA to describe functional performance of the lower body limbs. Variables describing the general physical status, including weekly consumption of kilocalories and the musculoskeletal index, were classified together with grip strength of the dominant hand as indicators of functional performance of the upper body limbs. An intimate association between the functional physical performance of the upper body limbs and the total antioxidant capacity was observed in older subjects. Low levels of total antioxidant capacity were found in women 76 years or younger with deficiencies in the physical performance of both upper and lower body limbs. Similarly, we observed a close association between the functional physical performance of the lower body limbs and the levels of hemoglobin. In particular, low levels of hemoglobin were mostly found in men older than 76 years of age, showing impaired functional physical performance. In addition, the physical performance of the lower body limbs was shown to be more important than that of the upper body limbs in the statistical association with pre-frailty in the elderly. Therefore, specific low levels of hemoglobin and deficient oxidative defense in the elderly could significantly affect the functional physical performance and future outcomes of pre-frailty.

Frailty and mortality, disability and mobility loss in a Spanish cohort of older adults: the FRADEA study.

BACKGROUND: Original Fried's frailty criteria have not demonstrated their prognostic validity of mortality, disability and mobility loss in European cohorts. OBJECTIVES: To analyze whether frailty implies increased risk of death, incident disability in basic (BADL) or instrumental (IADL) activities of daily living, or mobility impairment. DESIGN: Concurrent cohort study. SETTING: Albacete City, Spain. PARTICIPANTS: 993 participants over age 70 from the FRADEA Study. MEASUREMENTS: Mortality, BADL and mobility using the Barthel Index, and IADL using the Lawton IADL Index, were recorded. BADL disability was defined as loss of the ability to perform bathing, grooming, dressing, toilet use, or feeding, while deterioration of mobility was defined as loss of ability to perform transfers, walk, or use stairs, and IADL disability as losing any of the activities included in the Lawton Index. The risk of presenting adverse events was determined by Cox and Kaplan-Meier proportional hazard analysis and logistic regression adjusted for age, sex, function, and comorbidity. RESULTS: Mean follow-up was 534 days (SD 153), during which 105 participants (10.6%) died. Mean time to death was 363 days (SD 218), while 192 (25.4%) lost at least one BADL, 492 (60%) at least one IADL, and 222 (28.9%) lost mobility. Frail subjects had a greater adjusted risk of death (HR 5.5, CI 95% 1.5-20.2), of losing BADL (HR 2.5, CI 95% 1.3-4.8), of losing mobility (HR 2.7, CI 95% 1.5-5.0), and of losing IADL (HR 1.9, CI 95% 1.1-3.3) than non-frail patients. CONCLUSION: Fried's frailty criteria are associated with death, incident disability, and mobility impairment in a Spanish cohort of older adults.