Insights into the roles and driving forces of CCT3 in human tumors.

CCT3 played a key role in many cancers. This study aimed to further explore the characteristics of CCT3 from a pan-cancer perspective and reveal the driving forces for CCT3. By bioinformatic analysis, we found that the mRNA and protein levels of CCT3 were abnormally elevated in most tumor types and were correlated with poor prognosis. Single-cell sequencing data indicated an abnormal increase of CCT3 expression in both malignant cells and multiple immune cells. In the tumor microenvironment, CCT3 expression was negatively relevant with immune cell infiltration and immune checkpoint genes expression. In colon cancer, knockdown of CCT3 inhibited cell proliferation. Gene set enrichment analysis showed that CCT3 may be oncogenic by regulating amino acid metabolism. Furthermore, we predicted sensitive drugs for CCT3 by virtual screening and sensitivity analysis. Many driver genes such as TP53 and KRAS were essential for CCT3 overexpression. Epigenetic factors, enhancers in particular, were also critical for CCT3 expression. Additionally, we constructed the lncRNA/circRNA-miRNA-CCT3 regulatory network. Collectively, CCT3 had the potential to be a diagnostic and prognostic biomarker for multiple tumor types. CCT3 expression was relevant with an immunosuppressive tumor microenvironment. CCT3 could be a new molecular target for colon cancer. Both genetic and epigenetic factors were responsible for CCT3 expression in tumors.

Exploring the oncogenic roles of LINC00857 in pan-cancer.

Although aberrant LINC00857 expression may play a key role in oncogenesis, no research has analyzed the pan-cancer oncogenic roles of LINC00857, particularly in tumor immunology. Here, we integrated data from several databases to analyze the characteristics of LINC00857 in pan-cancer. We found that LINC00857 was overexpressed and correlated with a poor prognosis in a variety of cancers. Furthermore, high-expression of LINC00857 was negatively associated with immune cell infiltration and immune checkpoint gene expression. Notably, LINC00857 expression was negatively related to microsatellite instability and tumor mutation burden in colorectal cancer, implying poor reaction to immunotherapy when LINC00857 was highly expressed. Targeting LINC00857 could dramatically impair the proliferative ability of colorectal cancer cells. After RNA-sequencing in HCT116 cells, gene set enrichment analysis showed that LINC00857 may accelerate cancer progression by inhibiting the ferroptosis pathway and promoting glycolipid metabolism in colorectal cancer. Screening by weighted gene co-expression network analysis determined PIWIL4 as a target of LINC00857, which also performed an immunosuppressive role in colorectal cancer. Based on the structure of PIWIL4, a number of small molecule drugs were screened out by virtual screening and sensitivity analysis. In summary, LINC00857 expression was closely correlated with an immunosuppressive microenvironment and may be a novel diagnostic and prognostic biomarker for diverse cancers. The LINC00857/PIWIL4 axis may be predictive biomarkers for immunotherapy and valuable molecular targets for malignant tumors.

HSF1 Stimulates Glutamine Transport by Super-Enhancer-Driven lncRNA LINC00857 in Colorectal Cancer.

Super enhancers are critical for the gene transcription responsible for cell fate by interacting with transcription factors. However, the relevance of HSF1 to super enhancers in tumors remains obscure. We profiled H3K27ac enrichment by chromatin immunoprecipitation sequencing. HSF1-mediated lncRNAs were identified by lncRNA microarray. The characteristics of LINC00857 were explored by in vitro and in vivo assays. The mechanism was studied via chromatin immunoprecipitation, RNA immunoprecipitation, and HSF1/ANXA11 knockout mice. We found that super enhancers occupied multiple gene loci in colorectal cancer. We screened out an HSF1-mediated super enhancer, lncRNA-LINC00857, which exerts its characteristics in promoting cell growth via regulating glutamine metabolism. Notably, HSF1 could stimulate the super-enhancer activity of LINC00857 by the enrichment of acetyltransferase P300 to its gene loci, contributing to LINC00857 transcription. In turn, nuclear LINC00857 cooperated with HSF1 to promote ANXA11 transcription, which modulated SLC1A5/ASCT2 protein expression by binding competitively to miR-122-5p. The knockout of ANXA11 attenuated colorectal cancer formation in vivo. Collectively, we shed light on a closely cooperative machinery between HSF1 and super enhancers. HSF1 could stimulate acetyltransferase P300-mediated super-enhancer activity to facilitate LINC00857 expression, contributing to SLC1A5-mediated glutamine transport. Targeting the HSF1/LINC00857/ANXA11 axis may provide a valuable therapeutic strategy against colorectal cancer.

Pan-Cancer Analysis of the Roles and Driving Forces of RAB42.

RAB42 is a member of the RAS family. However, the roles and driving forces for RAB42 in tumors remain elusive. In this study, we performed a comprehensive pan-cancer analysis of the roles and regulatory mechanisms of RAB42 using bioinformatics and experiments. Online databases such as Sanger Box, ACLBI and TIDE were used to search for the expression levels, prognostic value and immune features of RAB42. We observed that RAB42 expression was upregulated in most tumors and was closely associated with poor prognosis. Enrichment analysis indicated that RAB42 was related to multiple biological functions, especially the immune process. RAB42 expression had a positive correlation with immune cell infiltration and immune checkpoint gene expression. RAB42 had a high predictive value for immunotherapy efficiency. Our study screened out susceptible drugs for the RAB42 protein by sensitivity analysis and virtual screening. Many key driver genes such as TP53 contributed to RAB42 expression. DNA methylation, super-enhancer and non-coding RNAs were the epigenetic factors responsible for RAB42 expression. In brief, RAB42 could serve as a diagnostic and prognostic biomarker in many tumor types. RAB42 might be a predictive biomarker and a new target for immunotherapy. Genetic and epigenetic factors were essential for RAB42 overexpression in tumors.

Prevalence of Osteoporosis and Fracture in China: The China Osteoporosis Prevalence Study.

Importance: The aging of the population is associated with an increasing burden of fractures worldwide. However, the epidemiological features of fractures in mainland China are not well known. Objective: To assess the prevalence of and factors associated with osteoporosis, clinical fractures, and vertebral fractures in an adult population 40 years or older in mainland China. Design, Setting. and Participants: This cross-sectional study, the China Osteoporosis Prevalence Study, was conducted from December 2017 to August 2018. A random sample of individuals aged 20 years or older who represented urban and rural areas of China were enrolled, with a 99% participation rate. Main Outcomes and Measures: Weighted prevalence of osteoporosis, clinical fracture, and vertebral fracture by age, sex, and urban vs rural residence as determined by x-ray absorptiometry, questionnaire, and radiography. Results: A total of 20 416 participants were included in this study; 20 164 (98.8%; 11 443 women [56.7%]; mean [SD] age, 53 [13] years) had a qualified x-ray absorptiometry image and completed the questionnaire, and 8423 of 8800 (95.7%) had a qualified spine radiograph. The prevalence of osteoporosis among those aged 40 years or older was 5.0% (95% CI, 4.2%-5.8%) among men and 20.6% (95% CI, 19.3%-22.0%) among women. The prevalence of vertebral fracture was 10.5% (95% CI, 9.0%-12.0%) among men and 9.7% (95% CI, 8.2%-11.1%) among women. The prevalence of clinical fracture in the past 5 years was 4.1% (95% CI, 3.3%-4.9%) among men and 4.2% (95% CI, 3.6%-4.7%) among women. Among men and women, 0.3% (95% CI, 0.0%-0.7%) and 1.4% (95% CI, 0.8%-2.0%), respectively, with osteoporosis diagnosed on the basis of bone mineral density or with fracture were receiving antiosteoporosis treatment to prevent fracture. Conclusions and Relevance: In this cross-sectional study of an adult population in mainland China, the prevalence of osteoporosis and vertebral fracture were high and the prevalence of vertebral fracture and clinical fracture was similarly high in men and women. These findings suggest that current guidelines for screening and treatment of fractures among patients in China should focus equally on men and women and should emphasize the prevention of vertebral fractures.

Hand grip strength is associated with cardiopulmonary function in Chinese adults: Results from a cross-sectional study.

BACKGROUND: The objective of this population-based study was to examine whether there was association of hand grip strength (HGS) with cardiopulmonary function in population without cardiopulmonary disease. METHODS: Data were derived from an ongoing cross-sectional survey of the National Physique and Health in Shanxi Province. There were 908 participants with the cardiac function tests and 380 participants with the pulmonary function tests. Multiple linear regression analysis was used to assess the association of HGS with cardiopulmonary function. RESULTS: Among participants with the cardiac function tests, HGS was positively associated with left ventricular end diastolic diameter in both genders (male: b = 0.010 (0.005, 0.015), P < 0.001; female: b = 0.008 (0.002, 0.014), P = 0.01) and left ventricular ejection fraction in males (b = 0.114 (0.027, 0.201), P = 0.01). Among participants with the pulmonary function tests, HGS was positively associated with vital capacity (male: b = 0.033 (0.021, 0.045); female: b = 0.033 (0.021, 0.045)), forced expiratory volume in 1 s (male: b = 0.023 (0.014, 0.032); female: b = 0.019 (0.010, 0.028)) and maximal voluntary ventilation (male: b = 1.186 (0.665, 1.708); female: b = 0.965 (0.453, 1.476)) in both genders (all P < 0.001). CONCLUSIONS: These results suggested that greater HGS was associated with favorable cardiopulmonary function in Chinese adults, thus HGS might be an indicator of cardiopulmonary function.

Neck circumference as an indicator of elevated blood pressure independent from body composition: implications from the China nation health survey (CNHS).

BACKGROUND: The independent association of neck circumference (NC) on elevated blood pressure is still uncertain in adults of China. The aim of this study is to explore such association and investigate the predictive value of NC on hypertension. METHODS: A total of 4279 adults aged 20-80 years participated in the cross-sectional study in 2014. Anthropometric information, NC, body composition indexes such as waist circumference, hip circumference and body fat percentage, and blood pressure were measured. General linear regression model was used to explore the association between NC and blood pressure; Logistic regression models were fitted to calculate the multi-variable adjusted prevalence, and the association of NC with hypertension. RESULTS: The overall prevalence of hypertension and pre-hypertension were 11.05 and 23.63%, respectively. NC was positively associated with both SBP and DBP (p < 0.001). The adjusted prevalence of hypertension increased with elevated NC quartiles in both sexes (p for trend < 0.001), from 17.81 to 42.93% in male and 9.72 to 21.31% in female. For male, NC was only associated with hypertension (OR: 1.15, 95% CI: 1.05-1.25) but not with pre-hypertension (OR: 0.97, 95% CI: 0.88-1.06). However, in female, NC was associated with both pre-hypertension and hypertension, the BMI adjusted ORs were 1.15 (1.03-1.28) and 1.24 (1.14-1.34). The sex-specific AUCs for NC predicting hypertension were 0.633 in male and 0.663 in female, similar with AUCs of other body fat indexes. CONCLUSIONS: NC was associated with both pre-HTN and HTN independent from other body composition indexes. NC is a simple and useful anthropometric index to identify elevated blood pressure in Chinese adults.

Body Composition and Serum Total Calcium Were Associated With Blood Pressure Among Children and Adolescents Aged 7-18 in China: A Cross-Sectional Study.

Background: This study aimed to assess the prevalence of childhood pre-hypertension and hypertension (elevated blood pressure, EBP) and explore their risk factors, especially the role of body composition and serum total calcium on EBP. Methods: From Nov 2013 to Jul 2014, a cross-sectional study was conducted in Hainan and Shaanxi Provinces in China. Two thousand two hundred eighty-three children and adolescents aged 7-18 underwent anthropometric and blood pressure measurements. Fasting blood was collected and serum total calcium was tested. Blood pressure standards from the updated Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents were used to classify BP groups based on age, sex and stature. Results: The overall prevalence of pre-hypertension and hypertension were 8.36 and 7.06%, respectively. Boys, older age, living in Hainan Province, excess adiposity and higher level of serum total calcium were found to be associated with EBP. Lean subjects had an average 3.87 mmHg decrease in systolic blood pressure (SBP) than normal weight groups. In contrary, overweight/obesity had increased SBP (3.69 mmHg) and diastolic blood pressure (DBP) (2.58 mmHg) than the normal weight group. Participants with high-level serum total calcium had a 1.60 mmHg increased SBP and 1.77 mmHg increased DBP than the low-level group. Compared with normal weight individuals, lean subjects appeared to have decreased odds of EBP (OR = 0.65, 95% CI: 0.43-0.98) but overweight/obese individuals were more likely to have EBP (OR = 2.67, 95% CI: 1.68-4.25). High-level of serum total calcium was associated with increased odds of EBP, the OR (95% CI) was 1.51 (1.17-1.94). The restrict cubic spline presented a linear relationship between serum total calcium and OR of EBP (P < 0.001). Conclusions: Body composition and serum total calcium were positively associated with blood pressure in children and adolescents. Serum calcium could be considered as an untraditional risk factors for high blood pressure screening along with other body composition indexes in clinical settings.

Expanded normal weight obesity and blood pressure in Chinese adults: a community-based cross-sectional study.

The study aimed to explore the independent association between expanded normal weight obesity categories and blood pressure among adults aged 20-80 years in China. By cross-sectional design, a total of 4279 adults living in Shaanxi Province, China, were selected from communities via multi-stage stratified cluster sampling in 2014. Information on anthropometric, body composition and blood pressure was collected and analysed. Expanded normal weight obesity (ENWO) categories were used to identify the level of bodyweight based on the combination of body mass index (BMI) and body fat percentage (BFP) categories. The age- and sex-standardised prevalence of hypertension increased within ENWO groups, from 10.12% in the underweight-low body fat group to 45.92% in the obesity-high body fat group. In under or normal weight participants, body fat percentage was found independently associated with hypertension in men, with an adjusted odds ratio of 3.69 in the fourth quartile of BFP compared with the first one. However, this effect was not observed in women. BFP was independently associated with increased risk of hypertension, especially in men. People with normal BMI should be re-identified as a high-risk population based on BFP level when it comes to hypertension prevention in primary healthcare settings.

Prevalence of, and biochemical and anthropometric risk factors for, dyslipidemia in children and adolescents aged 7 to 18 years in China: A cross-sectional study.

OBJECTIVE: This study aimed to investigate the prevalence of dyslipidemia and its risk factors in children and adolescents aged 7 to 18 years in China. METHODS: A cross-sectional study was conducted from November, 2013 to July, 2014. A total of 2283 children and adolescents from urban and rural areas in Hainan (South China) and Shaanxi Provinces (Northwest China) were selected using multi-stage stratified cluster sampling method. Each participant underwent anthropometric and serum biochemical tests which included serum lipids and hepatitis B virus surface antigen (HBsAg). RESULTS: The overall prevalence of high total cholesterol (TC), high triglyceride (TG), high low-density lipoprotein cholesterol (LDL-C), low high-density lipoprotein cholesterol (HDL-C), hyperlipidemia and dyslipidemia were 6.5%, 7.5%, 5.2%, 9.1%, 14.3%, and 20.6%, respectively. After standardization by age, girls had higher prevalence of high TC (8.2%), high LDL-C (6.6%), and hyperlipidemia (16.4%), but lower prevalence of low HDL-C (8.21%) than boys (4.2%, 3.4%, 11.9%, and 11.3%, respectively). The risk of dyslipidemia increased with age (OR = 1.067, 95% CI: 1.030-1.106). Boys had a decreased risk of dyslipidemia (OR = 0.798, 95% CI: 0.640-0.994). The restricted cubic spline revealed a linear relationship between BMI and the risk of dyslipidemia (P < .001). Subjects who were HBsAg positive had higher risk of dyslipidemia (OR = 1.550, 95% CI: 1.050-2.287) compared with those who were HBsAg negative. CONCLUSIONS: Our study highlights the high prevalence of dyslipidemia in youth in China, and is the first study to reveal a positive association between positive status for HBsAg and abnormal lipid levels in children and adolescents.

Muscle fitness and its association with body mass index in children and adolescents aged 7-18 years in China: a cross-sectional study.

BACKGROUND: The present study was the first one aimed to investigate the current muscle fitness and its associated factors among children and adolescents in mainland China. METHODS: From Nov 2013 to Jul 2014, 2283 children and adolescents aged 7-18 were recruited in Hainan and Shaanxi Provinces in China by cross-sectional design. Information on anthropometry and muscle fitness, measured by hand grip strength (GS), vertical jump (VJ) and sit-and-reach (SR), were collected. Analysis of covariance was performed by using general linear regression models to identify the association between BMI and muscle fitness. RESULTS: The means of GS, VJ and SR in boys were 22.30 ± 11.55 kg, 22.93 ± 6.80 cm and 3.58 ± 7.31 cm, respectively, and in girls were 16.61 ± 6.87 kg, 18.11 ± 4.08 cm and 7.18 ± 5.72 cm, respectively. GS (from 8.26 kg in the 7-8-year-old group to 27.91 kg in the 17-18 group) and SR (from 1.75 cm in the-8-year-old group to 10.12 cm in the 17-18 group) increased with age (both p for trend < 0.001). Boys had higher GS and VJ, but significantly lower SR than girls in each age group (p < 0.001). After adjusting for age, sex, residential areas and study regions, GS increased with elevated BMI (compared with normal weight group, the regression coefficient for thinness and overweight/obesity were - 2.997(95%CI: -3.693 to - 2.301) and 1.220 (95%CI: 0.285 to 2.155), respectively. With the p values less than 0.001 and 0.011, respectively). For VJ, there was no difference found between normal weight group and overweight/obesity group (p = 0.550), but the thinness group had the lowest performance (regression coefficient = - 2.681, 95%CI from - 3.965 to - 1.397, p < 0.001). For SR, compared with normal weight group, the regression coefficients for thinness and overweight/obesity were - 1.313(95%CI: -2.228 to - 0.399) and - 1.623(95%CI: -3.216 to - 0.030) respectively, both p < 0.05. CONCLUSIONS: Increased body weight may have a positive association with isometric muscle strength measured by grip strength, but a negative one with strength of lifting the body. Sex difference was also found in the performance of flexibility.

miR-185 affected the EMT, cell viability, and proliferation via DNMT1/MEG3 pathway in TGF-ß1-induced renal fibrosis.

Kidney fibrosis is usually the final manifestation of a wide variety of renal diseases. Recent years, research reported that long non-coding RNAs (lncRNAs) played important roles in a variety of human diseases. However, the role and underlying mechanisms of lncRNAs in kidney fibrosis were complicated and largely unclear. In our study, we constructed the cell model of renal fibrosis in HK2 cells using transforming growth factor ß1 (TGF-ß1) and found that lncRNA maternally expressed gene 3 (MEG3) was downregulated in TGF-ß1-induced renal fibrosis. We then found that overexpressed MEG3 inhibited the TGF-ß1-induced promotion of epithelial-mesenchymal transition, cell viability, and proliferation. Furthermore, we demonstrated that DNA methyltransferases 1 (DNMT1) regulated the MEG3 expression by altering the CpGs methylation level of MEG3 promoter in TGF-ß1-induced renal fibrosis. In addition, we further revealed that miR-185 could regulate the DNMT1 expression and thus, modulate the MEG3 in TGF-ß1-induced renal fibrosis. Ultimately, our study illustrated that the modulation of the miR-185/ DNMT1/ MEG3 pathway exerted important roles in TGF-ß1-induced renal fibrosis. In summary, our finding displayed a novel regulatory mechanism for TGF-ß1-induced renal fibrosis, which provided a new potential therapeutic target for renal fibrosis.

Association of Age-Related Trends in Blood Pressure and Body Composition Indices in Healthy Adults.

Purpose: Adiposity is one of the important determinants of blood pressure. The aim of this study is to evaluate the association between blood pressure and body composition indices throughout the whole lifespan of healthy adults. Patients and Methods: This study was from an ongoing cross-sectional survey of the Chinese health wherein data included basic physiological parameters. Partial Pearson correlation analysis was used to assess the correlation between blood pressure and body composition indices. Multiple linear regression analysis was used to assess the association of body mass index, lean mass percent, and visceral fat rating against blood pressure in each age group. Results: In the whole population stratified by gender, while body mass index had the highest r-value of correlation with systolic blood pressure in both males (r = 0.296, p < 0.001) and females(r = 0.237, p < 0.001), and fat mass percent had the highest r-value of correlation with diastolic blood pressure in males (r = 0.351, p < 0.001) and females(r = 0.277, p < 0.001), the strength of association with blood pressure were similar across most of the body composition indices. In multiple linear regression analysis, both body mass index and visceral fat rating were positively while lean mass percent was negatively associated with blood pressure in all age groups in both genders, whereas all the association was weaker in the elderly compared to the younger. Conclusion: Maintain the total body fat in a favorable range and appropriately increase the body muscle mass is a strategy to reduce the occurrence of cardiovascular event by decreasing the risk of hypertension through the whole adult life.

Different associations of sufficient and vigorous physical activity with BMI in Northwest China.

Physical activity (PA) plays an important role in maintaining a healthy weight. To develop targeted strategies that encourage physical activity, knowledge of associations between intensity of physical activity (PA) levels and body mass index (BMI) is essential. We aimed to examine the relationship between sufficient and vigorous PA and BMI distribution among adults in northwest China using quantile regression. We conducted a cross-sectional study in Shaanxi Province in 2013, using proportional probability sampling. BMI was calculated using measured height and weight. The Global Physical Activity Questionnaire was used to define and measure sufficient and vigorous PA. Associations of sufficient/vigorous PA and BMI were modelled using quantile regression. Mean BMI was 24.18 ± 3.51 and BMI distribution with age showed an inverse U shape. A total 9045 (88.97%) participants demonstrated sufficient PA and 3119 (30.68%) reported vigorous PA. After adjusting for relevant sociodemographic, dietary, and lifestyle parameters in quantile regression modelling, sufficient PA was positively associated with BMI score distribution from the 1st to 30th quantile, with ß from 0.32 (95% confidence interval (CI): 0.07 to 0.63) to 0.85 (95% CI: 0.40 to 1.19). Vigorous PA was negatively associated with BMI score distribution from the 30th to 93th quantiles, with ß from -0.18 (95% CI: -0.31 to -0.02) to -0.81 (95% CI: -1.10 to -0.45). Sufficient PA was positively associated with underweight and normal weight whereas vigorous PA was negatively associated with overweight and obesity.

Relative Handgrip Strength Is Inversely Associated with Metabolic Profile and Metabolic Disease in the General Population in China.

Background: Absolute handgrip strength has been correlated with metabolic profile and metabolic disease. Whether relative handgrip strength is also associated with metabolic disease has not been assessed. This study aimed at assessing the association of relative handgrip strength with metabolic profile and metabolic disease in the general population in China. Methods: Data were derived from an ongoing cross-sectional survey of the 2013 National Physical and Health in Shanxi Province, which involved 5520 participants. Multiple linear regression or multiple logistic regression analysis were used to assess the association of absolute/relative handgrip strength with the metabolic profile, preclinical, and established stages of metabolic diseases. Results: This study revealed that relative handgrip strength, that is when normalized to BMI, was associated with: (1) in both genders for more favorable blood lipid levels of high-density lipoprotein cholesterol [males: b = 0.19 (0.15, 0.23); females: b = 0.22 (0.17, 0.28)], low-density lipoprotein cholesterol [males: b = -0.14 (-0.23, -0.05); females: b = -0.19 (-0.31, -0.18)], triglycerides [males: b = -0.58 (-0.74, -0.43); females: b = -0.55 (-0.74, -0.36)] and total cholesterol [males: b = -0.20 (-0.31, -0.10); females: b = -0.19 (-0.32, -0.06)]; and better serum glucose levels in males [b = -0.30 (-0.46, -0.15)]. (2) lower risk of impaired fasting glucose in males {third quartile [OR = 0.66 (0.45-0.95)] and fourth quartile [OR = 0.46 (0.30-0.71)] vs. first quartile} and dyslipidemia in both genders {third quartile [males: OR = 0.65 (0.48-0.87); females: OR = 0.68 (0.53-0.86)] and fourth quartile [males: OR = 0.47 (0.35-0.64); females: OR = 0.47(0.36-0.61)] vs. first quartile}. (3) lower risk of hyperlipidemia in both genders third quartile [males: OR = 0.66 (0.50-0.87); females: OR = 0.57 (0.43-0.75)] and fourth quartile [males: OR = 0.35 (0.26-0.47); females: OR = 0.51 (0.38-0.70)] vs. first quartile. However, contrary to relative handgrip strength, higher absolute handgrip strength was associated with unfavorable metabolic profiles and higher risk of metabolic diseases. These paradoxical associations were retained even after adjusted for BMI by employed a multivariate analysis. Conclusion: We conclude that measurement of relative handgrip strength can be used as a reasonable clinical predictor of metabolic health and disease.

The electronic structure engineering of organic dye sensitizers for solar cells: The case of JK derivatives.

The design and development of novel dye sensitizers are effective method to improve the performance of dye-sensitized solar cells (DSSCs) because dye sensitizers have significant influence on photo-to-current conversion efficiency. In the procedure of dye sensitizer design, it is very important to understand how to tune their electronic structures and related properties through the substitution of electronic donors, acceptors, and conjugated bridges in dye sensitizers. Here, the electronic structures and excited-state properties of organic JK dye sensitizers are calculated by using density functional theory (DFT) and time dependent DFT methods. Based upon the calculated results, we investigated the role of different electronic donors, acceptors, and π-conjugated bridges in the modification of electronic structures, absorption properties, as well as the free energy variations for electron injection and dye regeneration. In terms of the analysis of transition configurations and molecular orbitals, the effective chromophores which are favorable for electron injection in DSSCs are addressed. Meanwhile, considering the absorption spectra and free energy variation, the promising electronic donors, π-conjugated bridges, and acceptors are presented to design dye sensitizers.

The Electronic Structures and Optical Properties of Alkaline-Earth Metals Doped Anatase TiO2: A Comparative Study of Screened Hybrid Functional and Generalized Gradient Approximation.

Alkaline-earth metallic dopant can improve the performance of anatase TiO2 in photocatalysis and solar cells. Aiming to understand doping mechanisms, the dopant formation energies, electronic structures, and optical properties for Be, Mg, Ca, Sr, and Ba doped anatase TiO2 are investigated by using density functional theory calculations with the HSE06 and PBE functionals. By combining our results with those of previous studies, the HSE06 functional provides a better description of electronic structures. The calculated formation energies indicate that the substitution of a lattice Ti with an AEM atom is energetically favorable under O-rich growth conditions. The electronic structures suggest that, AEM dopants shift the valence bands (VBs) to higher energy, and the dopant-state energies for the cases of Ca, Sr, and Ba are quite higher than Fermi levels, while the Be and Mg dopants result into the spin polarized gap states near the top of VBs. The components of VBs and dopant-states support that the AEM dopants are active in inter-band transitions with lower energy excitations. As to optical properties, Ca/Sr/Ba are more effective than Be/Mg to enhance absorbance in visible region, but the Be/Mg are superior to Ca/Sr/Ba for the absorbance improvement in near-IR region.

The adsorption of α-cyanoacrylic acid on anatase TiO2 (101) and (001) surfaces: a density functional theory study.

The adsorption of α-cyanoacrylic acid (CAA) on anatase TiO2 (101) and (001) surfaces, including adsorption energies, structures, and electronic properties, have been studied by means of density functional theory calculations in connection with ultrasoft pseudopotential and generalized gradient approximation based upon slab models. The most stable structure of CAA on anatase TiO2 (101) surface is the dissociated bidentate configuration where the cyano N and carbonyl O bond with two adjacent surface Ti atoms along [010] direction and the dissociated H binds to the surface bridging O which connects the surface Ti bonded with carbonyl O. While for the adsorption of CAA on (001) surface, the most stable structure is the bidentate configuration through the dissociation of hydroxyl in carboxyl moiety. The O atoms of carboxyl bond with two neighbor surface Ti along [100] direction, and the H from dissociated hydroxyl interacts with surface bridging O, generating OH species. The adsorption energies are estimated to be 1.02 and 3.25 eV for (101) and (001) surfaces, respectively. The analysis of density of states not only suggests the bonds between CAA and TiO2 surfaces are formed but also indicates that CAA adsorptions on TiO2 (101) and (001) surfaces provide feasible mode for photo-induced electron injection through the interface between TiO2 and CAA. This is resulted from that, compared with the contribution of CAA orbitals in valence bands, the conduction bands which are mainly composed of Ti 3d orbitals have remarkable reduction of the component of CAA orbitals.