Impact of sarcopenic obesity on heart failure in people with type 2 diabetes and the role of metabolism and inflammation: A prospective cohort study.

AIMS: We aimed to prospectively evaluate the association of sarcopenic obesity (SO) with the incidence risk of heart failure (HF), and the mediating role of metabolomics and inflammation in people with type 2 diabetes (T2D). METHODS: 22,496 participants with T2D from the UK Biobank were included. SO was defined as the combination of obesity (body mass index ≥30 kg/m2) and sarcopenia (grip strength <27 kg in male or <16 kg in female). The incident HF was identified through linked hospital records. Cox proportional hazard regression models were used to estimate the associations. Mediation analysis was conducted to evaluate the mediating effect of the "metabolomic risk score" of HF, which was derived from 168 plasma metabolites through LASSO regression, and five inflammatory markers (e.g., C-reactive protein [CRP] level) on the aforementioned associations. RESULTS: 1946 (8.7 %) participants developed HF during a median follow-up of 12.0 years. Compared to participants with neither obesity nor sarcopenia, those with obesity & non-sarcopenia (hazard ratio [HR]: 1.80, 95 % confidence interval [CI]: 1.62, 2.00), sarcopenia & non-obesity (HR: 1.90, 95 % CI: 1.56, 2.31) and SO (HR: 2.29, 95 % CI: 1.92, 2.73) showed a higher risk of HF. The metabolomic risk score (20.0 %) and CRP (20.4 %) meditated this association. CONCLUSIONS: SO was associated with an increased risk of HF in people with T2D and metabolomics and inflammation partially mediated this association. Our findings suggest the importance of managing obesity and muscle strength simultaneously in preventing HF among people with T2D and shed light on the underlying mechanisms.

The effect of weighted blankets on sleep and related disorders: a brief review.

Background: Sleep disorders such as insomnia can lead to a range of health problems. The high risk of side effects and drug abuse of traditional pharmacotherapy calls for a safer non-pharmacotherapy. Aims: To examine the use and efficacy of weighted blankets in improving sleep and related disorders in different populations and explore the possible mechanisms. Methods: A literature search was conducted using PubMed, Embase, Web of Science, MEDLINE, Cochrane Library and CNKI databases. Eligible studies included an intervention with weighted blankets and outcomes covering sleep and/or related disorders (behavioral disturbance, negative emotions and daytime symptoms). Studies using other deep pressure, compression, or exercise-related interventions were excluded. Conclusions: Most of the included studies showed that weighted blankets could effectively improve sleep quality and alleviate negative emotions and daytime symptoms in patients with sleep disorders, attention deficit hyperactivity disorder, autism spectrum disorder, and other related disorders, with a possible mechanism of deep pressure touch. Recommendations: Weighted blankets might be a promising tool for sleep interventions among individuals with sleep disorders in clinical settings. More high-quality and large-scale randomized controlled trials are needed to further validate the safety and efficacy of weighted blankets and explore precise mechanisms.

Trajectories of Body Mass Index and Waist Circumference in Relation to the Risk of Cardiac Arrhythmia: A Prospective Cohort Study.

BACKGROUND: The aim of the current study was to explore the trajectories, variabilities, and cumulative exposures of body mass index (BMI) and waist circumference (WC) with cardiac arrhythmia (CA) risks. METHODS: In total, 35,739 adults from the Kailuan study were included. BMI and WC were measured repeatedly during the 2006-2010 waves. CA was identified via electrocardiogram diagnosis. BMI and WC trajectories were fitted using a group-based trajectory model. The associations were estimated using Cox proportional hazards models. RESULTS: We identified four stable trajectories for BMI and WC, respectively. Neither the BMI trajectories nor the baseline BMI values were associated with the risk of CA. Compared to the low-stable WC group, participants in the high-stable WC group had a higher risk of CA (hazard ratio (HR) = 1.40, 95% confidence interval (CI): 1.06, 1.86). Interestingly, the cumulative exposures of BMI and WC instead of their variabilities were associated with the risk of CA. In the stratified analyses, the positive associations of the high-stable WC group with the risk of CA were found in females only (HR = 1.98, 95% CI: 1.02, 3.83). CONCLUSIONS: A high-stable WC trajectory is associated with a higher risk of CA among Chinese female adults, underscoring the potential of WC rather than BMI to identify adults who are at risk.

Implications for miR-339-5p regulation of trophoblast proliferation and migration in placentas associated with porcine intrauterine growth retardation using integrated transcriptome sequencing analysis.

Placental dysfunction is considered as one of the main etiologies of fetal intrauterine growth retardation (IUGR). MicroRNAs (miRNAs) have been demonstrated to be a vital epigenetic modification involved in regulating the placental function and pregnancy outcomes in mammals. However, the mechanisms underlying placenta-specific miRNAs involved in the occurrence and development of pig IUGR remain unclear. In this work, we compared the placental morphologies of piglets with IUGR and normal birth weight (NBW) by using histomorphological analysis and performed a miRNA-mRNA integrative analysis of the gene expression profiles of IUGR and NBW placentas through RNA sequencing. We also investigated the role of differentially expressed ssc-miR-339-5p/GRIK3 through an in vitro experiment on porcine trophoblast cells (PTr2). IUGR piglets had significantly lower birth weight, placental weight, placental efficiency, and placental villus and capillary densities compared with the NBW piglets (P < 0.05). A total of 81 differentially expressed miRNAs and 726 differentially expressed genes in the placentas were screened out between the IUGR and NBW groups. The miRNA-mRNA interaction networks revealed the key core miRNA (ssc-miR-339-5p) and its corresponding target genes. Subsequently, we found that upregulation of ssc-miR-339-5p significantly inhibited the migration and proliferation of PTr2 cells (P < 0.05). The dual-luciferase reporter system showed that GRIK3 was the target gene of ssc-miR-339-5p, and the transcription level of GRIK3 may be negatively regulated by ssc-miR-339-5p. Additionally, overexpression of ssc-miR-339-5p significantly increased (P < 0.05) the mRNA expression levels of genes involved in the cytokine-cytokine receptor interaction pathway. These results indicate that ssc-miR-339-5p may affect the migration and proliferation of trophoblast cells by regulating the expression of GRIK3 and altering the placental inflammatory response, resulting in a suboptimal morphology and function of the placenta and the development of pig IUGR.

Transition to healthier lifestyle associated with reduced risk of incident dementia and decreased hippocampal atrophy.

BACKGROUND: Research has estimated the associations of lifestyle at one-time point with the risk of dementia and hippocampal volume, but the impact of lifestyle transition on dementia and hippocampal volume remains unclear. This study aims to examine the associations of lifestyle transition with the risk of dementia and hippocampal volume. METHODS: Based on data from the UK Biobank, a weighted lifestyle score was constructed by incorporating six lifestyle factors. Within each baseline lifestyle group (i.e., healthy, intermediate, and unhealthy), lifestyle transition was classified into decline, maintenance, and improvement. Cox proportional hazard regression was used to estimate the association of lifestyle transition and incident dementia (N = 16,305). A multiple linear regression model was used to estimate the association between lifestyle transition and hippocampal volume (N = 5849). RESULTS: During a median follow-up period of 8.6 years, 120 (0.7 %) dementia events were documented. Among participants with healthy baseline lifestyles, the improvement group had a lower risk of incident dementia (HR: 0.18, 95 % CI: 0.04-0.81) and a larger hippocampal volume (ß = 111.69, P = 0.026) than the decline group. Similar results were observed among participants with intermediate baseline lifestyles regarding dementia risk but not hippocampal volume. No benefits were observed in the improvement group among those with unhealthy baseline lifestyles. LIMITATIONS: A lower incidence of dementia than other cohort study and this may have resulted in an underestimation of the risk of dementia. CONCLUSIONS: Earlier transitions to healthier lifestyle were associated with reduced risk of incident dementia and decreased hippocampal atrophy.

Accelerated aging mediates the associations of unhealthy lifestyles with cardiovascular disease, cancer, and mortality.

BACKGROUND: With two well-validated aging measures capturing mortality and morbidity risk, this study examined whether and to what extent aging mediates the associations of unhealthy lifestyles with adverse health outcomes. METHODS: Data were from 405,944 adults (40-69 years) from UK Biobank (UKB) and 9972 adults (20-84 years) from the US National Health and Nutrition Examination Survey (NHANES). An unhealthy lifestyles score (range: 0-5) was constructed based on five factors (smoking, drinking, physical inactivity, unhealthy body mass index, and unhealthy diet). Two aging measures, Phenotypic Age Acceleration (PhenoAgeAccel) and Biological Age Acceleration (BioAgeAccel) were calculated using nine and seven blood biomarkers, respectively, with a higher value indicating the acceleration of aging. The outcomes included incident cardiovascular disease (CVD), incident cancer, and all-cause mortality in UKB; CVD mortality, cancer mortality, and all-cause mortality in NHANES. A general linear regression model, Cox proportional hazards model, and formal mediation analysis were performed. RESULTS: The unhealthy lifestyles score was positively associated with PhenoAgeAccel (UKB: ß = 0.741; NHANES: ß = 0.874, all p < 0.001). We further confirmed the respective associations of PhenoAgeAccel and unhealthy lifestyles with the outcomes in UKB and NHANES. The mediation proportion of PhenoAgeAccel in associations of unhealthy lifestyles with incident CVD, incident cancer, and all-cause mortality were 20.0%, 17.8%, and 26.6% (all p < 0.001) in UKB, respectively. Similar results were found in NHANES. The findings were robust when using another aging measure-BioAgeAccel. CONCLUSIONS: Accelerated aging partially mediated the associations of lifestyles with CVD, cancer, and mortality in UK and US populations. The findings reveal a novel pathway and the potential of geroprotective programs in mitigating health inequality in late life beyond lifestyle interventions.

Sociodemographic Factors Predict Incident Mild Cognitive Impairment: A Brief Review and Empirical Study.

OBJECTIVES: Mild cognitive impairment (MCI) is a transitional stage between normal cognitive aging and dementia that increases the risk of progressive cognitive decline. Early prediction of MCI could be beneficial for identifying vulnerable individuals in the community and planning primary and secondary prevention to reduce the incidence of MCI. DESIGN: A narrative review and cohort study. SETTING AND PARTICIPANTS: We review the MCI prediction based on the assessment of sociodemographic factors. We included participants from 3 surveys: 8915 from wave 2011/2012 of the China Health and Retirement Longitudinal Study (CHARLS), 9765 from the 2011 Chinese Longitudinal Healthy Longevity Survey (CLHLS), and 1823 from the 2014 Rugao Longevity and Ageing Study (RuLAS). METHODS: We searched in PubMed, Embase, and Web of Science Core Collection between January 1, 2019, and December 30, 2022. To construct the composite risk score, a multivariate Cox proportional hazards regression model was used. The performance of the score was assessed using receiver operating characteristic (ROC) curves. Furthermore, the composite risk score was validated in 2 longitudinal cohorts, CLHLS and RuLAS. RESULTS: We concluded on 20 articles from 892 available. The results suggested that the previous models suffered from several defects, including overreliance on cross-sectional data, low predictive utility, inconvenient measurement, and inapplicability to developing countries. Our empirical work suggested that the area under the curve for a 5-year MCI prediction was 0.861 in CHARLS, 0.797 in CLHLS, and 0.823 in RuLAS. We designed a publicly available online tool for this composite risk score. CONCLUSIONS AND IMPLICATIONS: Attention to these sociodemographic factors related to the incidence of MCI can be beneficially incorporated into the current work, which will set the stage for better early prediction of MCI before its incidence and for reducing the burden of the disease.

Association of Sarcopenia with Cognitive Function and Dementia Risk Score: A National Prospective Cohort Study.

The relationship between skeletal muscle and cognitive disorders has drawn increasing attention. This study aims to examine the associations of sarcopenia with cognitive function and dementia risk score. Data on 1978 participants (aged 65 years and older) from the 2011 wave of the China Health and Retirement Longitudinal Study, with four follow-up waves to 2018, were used. Cognitive function was assessed by four dimensions, with a lower score indicating lower cognitive function. Dementia risk was assessed by a risk score using the Rotterdam Study Basic Dementia Risk Model (BDRM), with a higher score indicating a greater risk. Sarcopenia was defined when low muscle mass plus low muscle strength or low physical performance were met. We used generalized estimating equations to examine the associations of sarcopenia. In the fully adjusted models, sarcopenia was significantly associated with lower cognitive function (standardized, ß = -0.15; 95% CIs: -0.26, -0.04) and a higher BDRM score (standardized, ß = 0.42; 95% CIs: 0.29, 0.55). Our findings may provide a new avenue for alleviating the burden of cognitive disorders by preventing sarcopenia.

Association of frailty with the incidence risk of cardiovascular disease and type 2 diabetes mellitus in long-term cancer survivors: a prospective cohort study.

BACKGROUND: Comorbidities among cancer survivors remain a serious healthcare burden and require appropriate management. Using two widely used frailty indicators, this study aimed to evaluate whether frailty was associated with the incidence risk of cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM) among long-term cancer survivors. METHODS: We included 13,388 long-term cancer survivors (diagnosed with cancer over 5 years before enrolment) free of CVD and 6101 long-term cancer survivors free of T2DM, at the time of recruitment (aged 40-69 years), from the UK Biobank. Frailty was assessed by the frailty phenotype (FP_Frailty, range: 0-5) and the frailty index (FI_Frailty, range: 0-1) at baseline. The incident CVD and T2DM were ascertained through linked hospital data and primary care data, respectively. The associations were examined using Cox proportional hazards regression models. RESULTS: Compared with non-frail participants, those with pre-frailty (FP_Frailty [met 1-2 of the components]: hazard ratio [HR]=1.18, 95% confidence interval [CI]: 1.05, 1.32; FI_Frailty [0.10< FI ≤0.21]: HR=1.51, 95% CI: 1.32, 1.74) and frailty (FP_Frailty [met ≥3 of the components]: HR=2.12, 95% CI: 1.73, 2.60; FI_Frailty [FI >0.21]: HR=2.19, 95% CI: 1.85, 2.59) had a significantly higher risk of CVD in the multivariable-adjusted model. A similar association of FI_Frailty with the risk of incident T2DM was observed. We failed to find such an association for FP_Frailty. Notably, the very early stage of frailty (1 for FP_Frailty and 0.1-0.2 for FI_Frailty) was also positively associated with the risk of CVD and T2DM (FI_Frailty only). A series of sensitivity analyses confirmed the robustness of the findings. CONCLUSIONS: Frailty, even in the very early stage, was positively associated with the incidence risk of CVD and T2DM among long-term cancer survivors, although discrepancies existed between frailty indicators. While the validation of these findings is required, they suggest that routine monitoring, prevention, and interventive programs of frailty among cancer survivors may help to prevent late comorbidities and, eventually, improve their quality of life. Especially, interventions are recommended to target those at an early stage of frailty when healthcare resources are limited.

Transition of cooking fuel types and mortality risk in China, 1991-2015.

BACKGROUND: The decision for household cooking fuel choice is a complex and multi-dimensional process. This study aims to: 1) examine the trend of cooking fuel types during past decades; and 2) examine the association between switching from polluting to clean fuels for cooking and mortality risk. METHODS: This analysis included data on 39,359 participants from 9 waves of the China Health and Nutrition Survey (CHNS) (1991-2015). Participants with consistent polluting fuel use and with the polluting-to-clean transition were identified. Generalized estimating equations were used to examine the trend of clean fuel use from 1991 to 2015. Propensity score matching was used to address the data imbalance and confounding factors and Cox proportional hazards models were used to estimate the association. RESULTS: We found an increasing trend of clean fuel use after adjusting for potential confounders in the full sample (OR = 56.89, 95 % CI: 48.17, 67.19), which appeared to be more pronounced for those in rural areas and with low socioeconomic status. Switching from polluting to clean fuels was associated with a 75 % lower risk of mortality (HR = 0.25, 95 % CI: 0.11, 0.54). These associations became more pronounced during the lag period from 9 to 15 years. CONCLUSIONS: The transition from polluting to clean cooking fuels reduced excess deaths in China, particularly over a long period. Our findings support the increasing implementation of clean fuels and call for more efforts to improve its universal service, especially in rural and low socioeconomic status areas, to minimize health inequality.

Association of solid fuel use with a risk score capturing dementia risk among middle-aged and older adults: A prospective cohort study.

OBJECTIVES: Whether household air pollution is associated with dementia risk remains unknown. This study examined the associations between solid fuel use for cooking and heating (the main source of household air pollution) and dementia risk. METHODS: This analysis included data on 11,352 participants (aged 45+ years) from the 2011 wave of China Health and Retirement Longitudinal Study, with follow-up to 2018. Dementia risk was assessed by a risk score using the Rotterdam Study Basic Dementia Risk Model (BDRM), which was subsequently standardized for analysis. Household fuel types of cooking and heating were categorized as solid (e.g., coal and crop residue) and clean (e.g., central heating and solar). Multivariable analyses were performed using generalized estimating equations. Moreover, we examined the joint associations of solid fuel use for cooking and heating with the BDRM score. RESULTS: After adjusting for potential confounders, we found an independent and significant association of solid (vs. clean) fuel use for cooking and heating with a higher BDRM score (e.g., ß = 0.17 for solid fuel for cooking; 95% confidence interval [CI]: 0.15-0.19). Participants who used solid (vs. clean) fuel for both cooking and heating had the highest BDRM score (ß = 0.32; 95% CI: 0.29-0.36). Subgroup analysis suggested stronger associations in participants living in rural areas. CONCLUSIONS: Solid fuel use for cooking and heating was independently associated with increased dementia risk in Chinese middle-aged and older adults, particularly among those living in rural areas. Our findings call for more efforts to facilitate universal access to clean energy for dementia prevention.

Rational design and performance prediction of organic photosensitizer based on TATA+ dye for hydrogen production by photocatalytic decomposition of water.

In comparison to metal complexes, organic photosensitive dyes employed in photocatalytic hydrogen production exhibit promising developmental prospects. Utilizing the organic dye molecule TA+0 as the foundational structure, a series of innovative organic dyes, denoted as TA1-1 to TA2-6, were systematically designed. Employing first-principles calculations, we methodically explored the modifying effects of diverse electron-donating groups on the R1 and R2 positions to assess their application potential. Our findings reveal that, relative to the experimentally synthesized TATA+03, the TA2-6 molecule boasts a spatial structure conducive to intramolecular electron transfer, showcasing the most negative reduction potential (Ered = -2.11 eV) and the maximum reaction driving force (△G0 2 = -1.26 eV). This configuration enhances its compatibility with the reduction catalyst, thereby facilitating efficient hydrogen evolution. The TA2-6 dye demonstrates outstanding photophysical properties and a robust solar energy capture capacity. Its maximum molar extinction coefficient (ε) stands at 2.616 × 104 M-1·cm-1, representing a remarkable 292.8% improvement over TATA+03. In conclusion, this research underscores the promising potential of the TA2-6 dye as an innovative organic photosensitizer, positioning it as an efficacious component in homogeneous photocatalytic systems.

Does healthy lifestyle attenuate the detrimental effects of urinary polycyclic aromatic hydrocarbons on phenotypic aging? An analysis from NHANES 2001-2010.

Existing evidence has showed that exposure to polycyclic aromatic hydrocarbons (PAHs) increases the risk of many chronic diseases. Given the close connection between aging (a major risk factor) and chronic diseases, however, very few studies have evaluated the association between PAHs and aging. Furthermore, whether modifiable healthy lifestyle could attenuate the detrimental effect of PAHs on aging remains unknown. Therefore, we conducted this study, aiming to: (1) examine the associations of urinary monohydroxy polycyclic aromatic hydrocarbons (OH-PAHs) and lifestyle with Phenotypic Age Acceleration (PhenoAge.Accel), a novel aging measure that captures morbidity and mortality risk; and (2) evaluate the potential interaction effects of OH-PAHs and lifestyle on PhenoAge.Accel. Cross-sectional data of 2,579 participants (aged 20-84 years, n = 1,292 females) from the National Health and Nutrition Examination Survey for years 2001-2010 were analyzed. A lifestyle index was constructed based on five components (drinking, smoking, body mass index, physical activity, and diet), ranging from 0 to 5. We calculated PhenoAge.Accel using algorithms developed previously. General linear regression models were used to examine the associations. We observed strong associations of OH-PAHs and lifestyle with PhenoAge.Accel. For instance, one unit increase in ∑NAP (sum of 1- and 2-hydroxynaphthalene) was associated with 0.37 year (95% confidence interval [CI]: 0.26, 0.48) increase in PhenoAge.Accel. We did not observe statistically significant interaction effects between OH-PAHs and lifestyle on PhenoAge.Accel. After stratified by sex, we observed strong associations as well as statistically significant interactions of OH-PAHs and lifestyle with PhenoAge.Accel among females. In conclusion, both OH-PAHs and lifestyle were independently associated with phenotypic aging and there were statistically significant interactions between OH-PAHs and lifestyle on phenotypic aging among females. The findings highlight the importance of adherence to a healthy lifestyle to attenuate the detrimental effects of exposures to PAHs on phenotypic aging among females.

Novel Dyes Design Based on First Principles and the Prediction of Energy Conversion Efficiencies of Dye-Sensitized Solar Cells.

With the depletion of fossil energy, solar energy has gradually attracted people's attention. Dye-sensitized solar cells have developed rapidly in recent years due to their low cost and high conversion efficiency. In this article, based on the theoretical research on the photovoltaic parameters of DSSCs in the early stages of the research team, we have made an accurate prediction of J sc, V oc, and PCE of C286. (The error in our predicted PCE values was 3.33% relative to the experiment.) Also, we further designed a series of new dyes CH1-CH5 by introducing donors and co-acceptors with C286-C288 as the prototype using the DFT/TDDFT method. The PCE of the designed dyes CH2-CH5 exceed the given dye C286, especially the CH3 and CH4 obtained the PCE of 26.2 and 14.5%. This indicates the proposed dyes offer a dramatic improvement on PCE for DSSC devices. Moreover, the designed dyes such as CH3 and CH4 have great potential to be applied to photovoltaic applications, further enabling the design of novel, highly efficient photoactive materials.

Density functional theory design of double donor dyes and electron transfer on dye/TiO2(101) composite systems for dye-sensitized solar cells.

In this work, we designed a series of double donor organic dyes, named ME101-ME106, based on experimentally synthesized dye WD8, and further investigated their electronic structure, the stability of the dye/TiO2 (101) systems, density of states (DOS) and absorption spectra using density functional theory (DFT) and time-dependent DFT (TDDFT). The molar extinction coefficients of all designed dyes are higher than WD8. It's fascinating that ME106 exhibits a smallest energy gap and 75 nm redshifts compared to WD8. The results of calculations reveal that ME101-ME106/TiO2(101) surfaces are more stable than WD8, double donor dyes have sufficient electron injection driving force and have very strong transfer electron ability. It is expected that the design of double donors can provide a new understanding and guidance for the investigation of high efficiency dye-sensitized devices.

One-pot ultrasonic synthesis of multifunctional Au nanoparticle-ferrocene-WS2 nanosheet composite for the construction of an electrochemical biosensing platform.

Structuring of noble metal nanoparticles on transition metal dichalcogenide nanosheets induces significantly enhanced electronic, optical, and catalytic functions. However, the synthesis of multifunctional hybrids is always time-consuming and involves multiple steps. Herein, a ternary Au nanoparticle-ferrocene-WS2 nanosheet (AFW) composite has been prepared by a facile one-step sonochemical approach. Stripped WS2 nanosheets were functionalized with ferrocene monocarboxylic acid (FMC) and gold nanoparticles (AuNPs) by making use of the strong coordinative interaction of carboxyl groups with tungsten atoms. The AuNPs decorating the WS2 nanosheet not only increase the water solubility of WS2 nanosheet and surface area of the modified electrode, but also act as electron transport bridges to aid the tunneling of electrons from the small redox molecule, FMC, through the space to the electrode on which they are mounted. Furthermore, the ternary AFW nanocomposite could effectively avoid the leaching of FMC from the nanocomposite matrix and provided a suitable environment for the immobilized biomolecules. Combining the immune magnetic beads technology and the AFW nanocomposite with aforementioned advantages, a high-performance electrochemical immunosensor was successfully developed using carbohydrate antigen 72-4 (CA72-4) as a model analyte. A linear relationship in the range of 2-50 U/L for the detection of CA72-4 was found with a low detection limit of 0.6 U/L. In addition, the biosensor showed excellent performance in selectivity, stability, and reproducibility. Thus, this work not only proposes a facile avenue for preparing a 2D WS2 nanocomposite with multifunctional properties but also opens up a new method to extend the application of WS2-based materials in biological sensing.

Rational design of visible light panchromatic absorption laser dye molecules: The first principle study.

Laser dye molecules play an important role in tunable lasers due to enhancing the laser radiation intensity and increasing the laser adjustable range. The broad spectral bandwidth and visible light absorption allows for the evaluation of multiple fluorescence quenching mechanisms such as excition formation, photoinduced electron transfer, and excited-state proton transfer. A series of organic dye molecules (LD1-4、LA2-5、LU1-5、LV1-4、LI1-4) consisting of simple electron donor (D), conjugated bridge (π) and electron acceptor (A) units were designed using first-principles calculations in order to evaluate their potential for applications in tunable lasers. Furthermore, the optical and electronic properties of the dye molecules are analyzed in detail using density functional theory (DFT) and time-dependent density functional theory (TDDFT), including spectral parameters, energy levels and orbital contributions of organic dye molecules. The results indicate that LI1-3 show high molar extinction coefficient, visible light full color absorption and obvious red-shifted compared to the experimentally synthesized dye LA3. In particular, the newly designed LI3 exhibits not only a 190 nm red-shifted and a higher molar extinction coefficient with an increment of 19%, but also has an extremely broad absorption spectrum covering entire visible absorption spectrum from 380 to 750 nm compared to LD1. We also find that the dyes with dithiophene groups and naphthalene group as the electron donors are better absorption spectrum than dyes with double bond group and benzene group. These calculated results will hopefully contribute to the further development of novel laser dye molecules and further provide scientific support and theoretical guidance for subsequent related research.

Design of butterfly type organic dye sensitizers with double electron donors: The first principle study.

In this work, we designed a series of butterfly type organic dyes, named ME07-ME13 by introducing such as triphenylamine, phenothiazine, coumarin groups etc. as electron donors and further investigated their absorption spectra using density functional theory (DFT) and time-dependent DFT (TDDFT). All designed dyes cover the entire visible absorption spectrum from 300 to 800nm. It's fascinating that ME13 molecule has two absorption peak and the molar coefficient of two absorption peaks are above 4.645×104M-1·cm-1. The light absorption area of ME13 exhibits an increment of 16.5-19.1% compared to ME07-ME12. Furthermore, we performed a detailed analysis on their geometrical and electronic properties, including molecular structures, energy levels, light harvesting efficiency (LHE), driving force (ΔGinject), regeneration (ΔGregen),electron dipole moments (µnormal), intermolecular electron transfer and dye/(TiO2)38 system electron transitions. The results of calculation reveal that double coumarin donors in ME13 are promising functional groups for butterfly type organic dye sensitizers. It is expected that the design of double donors can provide a new strategy and guidance for the investigation in high efficiency dye-sensitized devices.

Effect of auxiliary group for p-type organic dyes in NiO-based dye-sensitized solar cells: The first principal study.

Auxiliary acceptor groups play a crucial role in D-A-π-A structured organic dyes. In this paper, we designed three D-A-π-A structured organic molecules based on the prototype dye QT-1, named ME18-ME20, and further investigated their electronic and optical properties with density functional theory (DFT) and time-dependent DFT (TDDFT). The calculated results indicate that the scope and intensity of dyes' absorption spectra have some outstanding changes by inserting auxiliary groups. ME20 has not only 152nm redshifts to long wave orientation, but also 78% increased oscillator strength compared to QT-1, and its absorption spectrum broadens region even up to 1400nm. Then, we studied the reason that the effect of the introduced different auxiliary acceptor groups in these dyes through their ground states geometries and energy levels, electron transfer and recombination rate.