Targeted delivery of an anti-inflammatory corticosteroid to Ly6C/G-positive cells abates severity of influenza A symptoms.

The distribution of Ly6C/G-positive cells in response to an infection of the mouse respiratory tract with influenza A virus was followed noninvasively over time by immuno-positron emission tomography. We converted nanobodies that recognize Ly6C and Ly6G, markers of neutrophils and other myeloid cells, as well as an influenza hemagglutinin-specific nanobody, into 89Zr-labeled PEGylated positron emission tomography (PET) imaging agents. The PET images showed strong accumulation of these imaging agents in the lungs of infected mice. Immunohistochemistry of influenza virus-infected mice and control mice, injected with a biotinylated and PEGylated version of the Ly6C/G-specific nanobody, showed the presence of abundant Ly6C/G-positive myeloid cells and positivity for Ly6C/G on bronchial epithelium in influenza virus-infected mice. This is consistent with focal inflammation in the lungs, a finding that correlated well with the immuno-PET results. No such signals were detected in control mice. Having shown by PET the accumulation of the Ly6C/G-specific nanobody in infected lungs, we synthesized conjugates of Ly6C/G-specific nanobodies with dexamethasone to enable targeted delivery of this immunosuppressive corticosteroid to sites of inflammation. Such conjugates reduced the weight loss that accompanies infection, while the equivalent amount of free dexamethasone was without effect. Nanobody-drug conjugates thus enable delivery of drugs to particular cell types at the appropriate anatomic site(s). By avoiding systemic exposure to free dexamethasone, this strategy minimizes its undesirable side effects because of the much lower effective dose of the nanobody-dexamethasone conjugate. The ability to selectively target inflammatory cells may find application in the treatment of other infections or other immune-mediated diseases.

Minimization of Energy Level Mismatch of PCBM and Surface Passivation for Highly Stable Sn-Based Perovskite Solar Cells by Doping n-Type Polymer.

Developing high-performance and stable Sn-based perovskite solar cells (PSCs) is difficult due to the inherent tendency of Sn2+ oxidation and, the huge energy mismatch between perovskite and Phenyl-C61-butyric acid methyl ester (PCBM), a frequently employed electron transport layer (ETL). This study demonstrates that perovskite surface defects can be passivated and PCBM's electrical properties improved by doping n-type polymer N2200 into PCBM. The doping of PCBM with N2200 results in enhanced band alignment and improved electrical properties of PCBM. The presence of electron-donating atoms such as S, and O in N2200, effectively coordinates with free Sn2+ to prevent further oxidation. The doping of PCBM with N2200 offers a reduced conduction band offset (from 0.38 to 0.21 eV) at the interface between the ETL and perovskite. As a result, the N2200 doped PCBM-based PSCs show an enhanced open circuit voltage of 0.79 V with impressive power conversion efficiency (PCE) of 12.98% (certified PCE 11.95%). Significantly, the N2200 doped PCBM-based PSCs exhibited exceptional stability and retained above 90% of their initial PCE when subjected to continuous illumination at maximum power point tracking for 1000 h under one sun.

Hippocampal acetylcholine modulates stress-related behaviors independent of specific cholinergic inputs.

Acetylcholine (ACh) levels are elevated in actively depressed subjects. Conversely, antagonism of either nicotinic or muscarinic ACh receptors can have antidepressant effects in humans and decrease stress-relevant behaviors in rodents. Consistent with a role for ACh in mediating maladaptive responses to stress, brain ACh levels increase in response to stressful challenges, whereas systemically blocking acetylcholinesterase (AChE, the primary ACh degradative enzyme) elicits depression-like symptoms in human subjects, and selectively blocking AChE in the hippocampus increases relevant behaviors in rodents. We used an ACh sensor to characterize stress-evoked ACh release, then used chemogenetic, optogenetic and pharmacological approaches to determine whether cholinergic inputs from the medial septum/diagonal bands of Broca (MSDBB) or ChAT-positive neurons intrinsic to the hippocampus mediate stress-relevant behaviors in mice. Chemogenetic inhibition or activation of MSDBB cholinergic neurons did not result in significant behavioral effects, while inhibition attenuated the behavioral effects of physostigmine. In contrast, optogenetic stimulation of septohippocampal terminals or selective chemogenetic activation of ChAT-positive inputs to hippocampus increased stress-related behaviors. Finally, stimulation of sparse ChAT-positive hippocampal neurons increased stress-related behaviors in one ChAT-Cre line, which were attenuated by local infusion of cholinergic antagonists. These studies suggest that ACh signaling results in maladaptive behavioral responses to stress if the balance of signaling is shifted toward increased hippocampal engagement.

Converting an Anti-Mouse CD4 Monoclonal Antibody into an scFv Positron Emission Tomography Imaging Agent for Longitudinal Monitoring of CD4+ T Cells.

Immuno-positron emission tomography (PET), a noninvasive imaging modality, can provide a dynamic approach for longitudinal assessment of cell populations of interest. Transformation of mAbs into single-chain variable fragment (scFv)-based PET imaging agents would allow noninvasive tracking in vivo of a wide range of possible targets. We used sortase-mediated enzymatic labeling in combination with PEGylation to develop an anti-mouse CD4 scFv-based PET imaging agent constructed from an anti-mouse CD4 mAb. This anti-CD4 scFv can monitor the in vivo distribution of CD4+ T cells by immuno-PET. We tracked CD4+ and CD8+ T cells in wild-type mice, in immunodeficient recipients reconstituted with monoclonal populations of OT-II and OT-I T cells, and in a B16 melanoma model. Anti-CD4 and -CD8 immuno-PET showed that the persistence of both CD4+ and CD8+ T cells transferred into immunodeficient mice improved when recipients were immunized with OVA in CFA. In tumor-bearing animals, infiltration of both CD4+ and CD8+ T cells increased as the tumor grew. The approach described in this study should be readily applicable to convert clinically useful Abs into the corresponding scFv PET imaging agents.

'He was a brilliant student but became mad like his grandfather': an exploratory investigation on the social perception and stigma against individuals living with mental health problems in Bangladesh.

BACKGROUND: Worldwide, mental health issues constitute a substantial threat to people's social, economic, and mental well-being and contribute significantly to many fatalities each year. In Bangladesh, people with mental health issues typically delay contacting health professionals because they prefer traditional or religious healers. Moreover, the situation is exacerbated by a lack of awareness, social stigma, and negative perception of sufferers of mental health issues on the part of families and the community. Therefore, this paper investigates the social perception and stigmatization of individuals living with mental health problems and their caregivers in Khulna, Bangladesh. METHODS: Data were collected from university students with concurring mental health issues as well as their closest caregivers, who had in-depth knowledge of the problem and a willingness to take care of the individuals with mental health issues. Following the criteria for data collection, eight individuals living with mental health problems and five caregivers were purposively selected for this research. A semi-structured in-depth interview guide was used for the confidential data collection process, which took place in November and December 2021, and each interview lasted 40-50 min on average. RESULTS: This study used thematic analysis to present the results; the findings showed that: individuals afflicted with mental health problems sought both medical and spiritual support to recover. Those with mental health issues who received positive family support recovered relatively faster than those who did not. However, negative social perception and stigmatization were the key impediments for individuals suffering from mental health problems and their families, as they found it difficult to discuss their issues with relatives and communities when attempting to access support or seek remedies. Moreover, the commonality of social stigmas, such as labeling mental health problems as equal to 'madness,' hindered disclosure to family members, peers, and the community. CONCLUSION AND RECOMMENDATIONS: In Bangladesh, the majority of individuals living with mental health problems are stigmatized and do not receive emotional support. Hence, we suggest nationwide community-based awareness-building programs to promote more positive perceptions of the fight against mental health disorders. Furthermore, counseling and awareness-building programs for effective discouragement of non-scientific remedies such as spiritual healing, as well as diagnosis and medication at the primary stage of sickness, are recommended for early detection and better medical assistance.

Identification of visible colored dissolved organic matter in biological and tertiary municipal effluents using multiple approaches including PARAFAC analysis.

This study provided insights into the persistent yellowish color in biological and tertiary effluents of municipal wastewater through a multi-characterization approach and fluorescence excitation-emission matrix-parallel factor (EEM-PARAFAC) analysis. The characterization was performed on three to five full-scale municipal wastewater treatment plants (WWTPs), including differential log-transformed absorbance (DLnA) spectroscopy, resin fractionation, size-exclusion chromatography for apparent molecular weight analysis (SEC-AMW), and X-ray photoelectron spectroscopy (XPS) analysis. Hydrophobic acids (HPOA) were abundant in visible colored dissolved organic matter (DOM). The SEC-AMW result showed that the molecular weight of the colored substances in the secondary effluents is mainly distributed in the range of 2-3 kDa. Through XPS analysis, C-O/C-N and pyrrolic/pyridonic (N-5) were found to be positively correlated with chroma. PARAFAC component models were built on biological (two components) and tertiary effluent (three components) and the correlation analysis revealed that PARAFAC component 2 in biological effluent (BE-C2) and component 1 in tertiary effluent (TE-C1), which were ascribed to Hydrophobic acids and Humic acid-like, were the responsible visible colored DOM components cause yellowish color. In addition, component similarity testing found that the identified visible colored DOM PARAFAC BE-C2, and PARAFAC TE-C1 were identical (0.96) in physicochemical properties, with 4% removal efficacy on average, compared with 11% for invisible colored DOM. This implied that tertiary effluents containing colorants (TE-C1) were resistant to degradation/removal using different disinfection and filtration processes in advanced treatments. This sheds light on many physicochemical aspects of PARAFAC-identified visible colored DOM components and provides spectral data to build an online monitoring system.

Immunobiology of cancer-associated fibroblasts in the context of radiotherapy.

Radiotherapy (RT) still represents a mainstay of treatment in clinical oncology. Traditionally, the effectiveness of radiotherapy has been attributed to the killing potential of ionizing radiation (IR) over malignant cells, however, it has become clear that therapeutic efficacy of RT also involves activation of innate and adaptive anti-tumor immune responses. Therapeutic irradiation of the tumor microenvironment (TME) provokes profound cellular and biological reconfigurations which ultimately may influence immune recognition. As one of the major constituents of the TME, cancer-associated fibroblasts (CAFs) play central roles in cancer development at all stages and are recognized contributors of tumor immune evasion. While some studies argue that RT affects CAFs negatively through growth arrest and impaired motility, others claim that exposure of fibroblasts to RT promotes their conversion into a more activated phenotype. Nevertheless, despite the well-described immunoregulatory functions assigned to CAFs, little is known about the interplay between CAFs and immune cells in the context of RT. In this review, we go over current literature on the effects of radiation on CAFs and the influence that CAFs have on radiotherapy outcomes, and we summarize present knowledge on the transformed cellular crosstalk between CAFs and immune cells after radiation.

Chemical passivation of the under coordinated Pb2+ defects in inverted planar perovskite solar cells via ß-diketone Lewis base additives.

Hybrid organic-inorganic perovskite solar cells (PSCs) are promising new generations of solar cells, which is low in cost with high power conversion efficiency (PCE). However, PSCs suffer from structural defects generated from the under coordinated ions at the surface, which limits their photovoltaic performances. Herein we report, two ß-diketone Lewis base additives 2,4-pentanedione and 3-methyl-2,4-nonanedione within the chlorobenzene anti-solvent to passivate the surface defects generated from the under coordinated Pb2+ ions in CH3NH3PbI3 perovskite films. The incorporation of the two ß-diketone passivators could successfully enhance the open-circuit voltage of the PSCs by 52 mV and 17 mV for 3-methyl-2,4-nonanedione and 2,4-pentanedione, respectively, with improved PCE by 45% for 3-methyl-2,4-nonanedione compared to the pristine PSC. This enhancement in the photovoltaic performance of the PSCs can be attributed to passivation of the defects through the interaction between two carbonyl groups of the ß-diketone Lewis base additives and the under coordinated Pb2+ defects in the perovskite film, which improved the PSCs PCE and stability.

Evaluation of medication adherence among patients with chronic diseases in Saudi Arabia.

BACKGROUND: Medication adherence in chronic diseases patients is a worldwide concern. Not achieving the goal of treatments because of non-adherence will lead to more complications and eventually may lead to death. In Saudi Arabia, we have insufficient data for interpretation. Hence, this study aims to have a better perspective at the number of the non-adherent patients with chronic diseases to their medications and its associated factors. MATERIAL AND METHOD: Cross-sectional quantitative study was conducted among chronic diseases patients living in Saudi Arabia throughout social media and hospital visits from August 2018 to April 2019. A three-section questionnaire consists of patient's health, medications and adherence characteristics. Adherence to Refills and Medication Scale (ARMS) was used to identify the level of adherence among chronic diseases patients. Univariate descriptive statistics and independent sample t-test with one-way ANOVA were used as bivariate analysis. Finally, significant predictors of medical adherence with adjusted coefficient were determined by multivariable linear regression. RESULTS: A total of 385 patients were included in the analysis for the current study. Overall, 96.62% (n = 372) were non-adherent to their medications according to ARMS scale. Multiple linear regression model found types of co-morbidities, medication dosage form and dosage regimen to be independent predictors of medical adherence. CONCLUSION: Medication adherence is alarmingly low among chronic disease patients in Saudi Arabia. There is a clear need for in-depth understanding for barriers. It is therefore important to conduct a qualitative study. What's known Medication adherence is a critical factor in treatment success. Low adherence to the medication is a common problem among chronic disease patients. Moreover, the majority of the studies in Saudi Arabia showed low adherence rate, and it focused in one single chronic disease only despite that patient may have more. What's new Most patients had more than one single chronic disease, so this study aims to take a snapshot to capture the adherence rate among patients who are suffering from chronic disease Saudi Arabia and its associated factors. This can help in understanding medication adherence behavior in clinical practice.

Impact of A-D-A-Structured Dithienosilole- and Phenoxazine-Based Small Molecular Material for Bulk Heterojunction and Dopant-Free Perovskite Solar Cells.

Herein, the synthesis of the novel acceptor-donor-acceptor (A-D-A)-structured small molecule Si-PO-2CN based on dithienosilole (DTS) as building block flanked by electron-rich phenoxazine (POZ) units, which are terminated with dicyanovinylene, is presented. Si-PO-2CN showed unique electrochemical and photophysical properties and has been successfully employed in perovskite solar cells (PSCs) as well as in bulk heterojunction organic solar cells (OSCs). The PSCs fabricated with dopant-free Si-PO-2CN as hole-transport material (HTM) exhibited a power conversion efficiency (PCE) of 14.1 % (active area=1.02 cm2 ). Additionally, a PCE of 5.6 % has been achieved for OSCs, which employed Si-PO-2CN as p-type donor material when blended with a [6,6]-phenyl C71 butyric acid methyl ester (PC71 BM) acceptor. The versatile application of Si-PO-2CN provides a pathway for further implementation of DTS-based building blocks in solar cells for designing new molecules.

In vitro chondrogenic potency of surplus chondrocytes from autologous transplantation procedures does not predict short-term clinical outcomes.

BACKGROUND: Autologous chondrocyte implantation (ACI) has been used over the last two decades to treat focal cartilage lesions aiming to delay or prevent the onset of osteoarthritis; however, some patients do not respond adequately to the procedure. A number of biomarkers that can forecast the clinical potency of the cells have been proposed, but evidence for the relationship between in vitro chondrogenic potential and clinical outcomes is missing. In this study, we explored if the ability of cells to make cartilage in vitro correlates with ACI clinical outcomes. Additionally, we evaluated previously proposed chondrogenic biomarkers and searched for new biomarkers in the chondrocyte proteome capable of predicting clinical success or failure after ACI. METHODS: The chondrogenic capacity of chondrocytes derived from 14 different donors was defined based on proteoglycans staining and visual histological grading of tissues generated using the pellet culture system. A Lysholm score of 65 two years post-ACI was used as a cut-off to categorise "success" and "failure" clinical groups. A set of predefined biomarkers were investigated in the chondrogenic and clinical outcomes groups using flow cytometry and qPCR. High-throughput proteomics of cell lysates was used to search for putative biomarkers to predict chondrogenesis and clinical outcomes. RESULTS: Visual histological grading of pellets categorised donors into "high" and "low" chondrogenic groups. Direct comparison between donor-matched in vitro chondrogenic potential and clinical outcomes revealed no significant associations. Comparative analyses of selected biomarkers revealed that expression of CD106 and TGF-ß-receptor-3 was enhanced in the low chondrogenic group, while expression of integrin-α1 and integrin-ß1 was significantly upregulated in the high chondrogenic group. Additionally, increased surface expression of CD166 was observed in the clinical success group, while the gene expression of cartilage oligomeric matrix protein was downregulated. High throughput proteomics revealed no differentially expressed proteins from success and failure clinical groups, whereas seven proteins including prolyl-4-hydroxylase 1 were differentially expressed when comparing chondrogenic groups. CONCLUSION: In our limited material, we found no correlation between in vitro cartilage-forming capacity and clinical outcomes, and argue on the limitations of using the chondrogenic potential of cells or markers for chondrogenesis as predictors of clinical outcomes.

Design and Evaluation of Sensor Housing for Boundary Layer Profiling Using Multirotors.

Traditional configurations for mounting Temperature-Humidity (TH) sensors on multirotor Unmanned Aerial Systems (UASs) often suffer from insufficient radiation shielding, exposure to mixed and turbulent air from propellers, and inconsistent aspiration while situated in the wake of the UAS. Descent profiles using traditional methods are unreliable (when compared to an ascent profile) due to the turbulent mixing of air by the UAS while descending into that flow field. Consequently, atmospheric boundary layer profiles that rely on such configurations are bias-prone and unreliable in certain flight patterns (such as descent). This article describes and evaluates a novel sensor housing designed to shield airborne sensors from artificial heat sources and artificial wet-bulbing while pulling air from outside the rotor wash influence. The housing is mounted above the propellers to exploit the rotor-induced pressure deficits that passively induce a high-speed laminar airflow to aspirate the sensor consistently. Our design is modular, accommodates a variety of other sensors, and would be compatible with a wide range of commercially available multirotors. Extensive flight tests conducted at altitudes up to 500 m Above Ground Level (AGL) show that the housing facilitates reliable measurements of the boundary layer phenomena and is invariant in orientation to the ambient wind, even at high vertical/horizontal speeds (up to 5 m/s) for the UAS. A low standard deviation of errors shows a good agreement between the ascent and descent profiles and proves our unique design is reliable for various UAS missions.

Exclusive breastfeeding practice during first six months of an infant's life in Bangladesh: a country based cross-sectional study.

BACKGROUND: Breastfeeding offers incredible health benefits to both child and mother. It is suggested by World Health Organization that an able mother should practice and maintain exclusive breastfeeding for first six months of her infant's life. The objective of this study was to determine the prevalence and factors associated with exclusive breastfeeding for first six months of an infant's life in Bangladesh. METHODS: Data was extracted from Bangladesh Demographic and Health Survey (BDHS-2014). BDHS-2014 collected data from 17,863 Bangladeshi married women in reproductive age from the entire country using two stages stratified cluster sampling. We included only mothers having at least one child currently aged not less than 6 months. Mothers who did not have child to breastfeed, some incomplete information and missing samples were excluded from the data set and consequently 3541 mothers were considered in the present study. Chi-square test, binary logistic regression models were used in this study. RESULTS: The prevalence of exclusive breastfeeding (EBF) for first six months of an infant's life in Bangladesh was 35.90%. Binary multivariable logistic regression model demonstrated that relatively less educated mothers were more likely to exclusively breastfeed their children than higher educated mothers. (AOR = 2.28, 95% CI: 1.05-4.93; p < 0.05). Housewife mothers were more likely to be EBF than their counterparts (AOR = 1.20, 95% CI: 1.02-1.42; p < 0.05). Higher rate of EBF was especially found among mothers who were living in Sylhet division, within 35-49 years old, and had access to mass media, had more than 4 children, had delivered at home and non-caesarean delivery, took breastfeeding counseling, antenatal and postnatal cares. CONCLUSIONS: Stepwise regression model exhibited that most of the important predictors were modifiable factors for exclusive breastfeeding. Authorities should provide basic education on EBF to educated mothers, and organize more general campaign on EBF.

Plagiochiline A Inhibits Cytokinetic Abscission and Induces Cell Death.

We previously reported on the isolation and biological activities of plagiochiline A (1), a 2,3-secoaromadendrane-type sesquiterpenoid from the Peruvian medicinal plant, Plagiochila disticha. This compound was found to have antiproliferative effects on a variety of solid tumor cell lines, as well as several leukemia cell lines. Other researchers have also noted the cytotoxicity of plagiochiline A (isolated from different plant species), but there are no prior reports regarding the mechanism for this bioactivity. Here, we have evaluated the effects of plagiochiline A on cell cycle progression in DU145 prostate cancer cells. A cell cycle analysis indicated that plagiochiline A caused a significant increase in the percentage of cells in the G2/M phase when compared with control cells. When cells were stained and observed by fluorescence microscopy to examine progress through the mitotic phase, we found a significant increase in the proportion of cells with features of late cytokinesis (cells connected by intercellular bridges) in the plagiochiline A-treated samples. These results suggest that plagiochiline A inhibits cell division by preventing completion of cytokinesis, particularly at the final abscission stage. We also determined that plagiochiline A reduces DU145 cell survival in clonogenic assays and that it induces substantial cell death in these cells.

Prospects of Graphene as a Potential Carrier-Transport Material in Third-Generation Solar Cells.

Third-generation solar cells are understood to be the pathway to overcoming the issues and drawbacks of the existing solar cell technologies. Since the introduction of graphene in solar cells, it has been providing attractive properties for the next generation of solar cells. Currently, there are more theoretical predictions rather than practical recognitions in third-generation solar cells. Some of the potential of graphene has been explored in organic photovoltaics (OPVs) and dye-sensitized solar cells (DSSCs), but it has yet to be fully comprehended in the recent third-generation inorganic-organic hybrid perovskite solar cells. In this review, the diverse role of graphene in third-generation OPVs and DSSCs will be deliberated to provide an insight on the prospects and challenges of graphene in inorganic-organic hybrid perovskite solar cells.

Near-infrared squaraine co-sensitizer for high-efficiency dye-sensitized solar cells.

A combination of squaraine-based dyes (SPSQ1 and SPSQ2) and a ruthenium-based dye (N3) were chosen as co-sensitizers to construct efficient dye-sensitized solar cells. The co-sensitization of squaraine dyes with N3 enhanced their light-harvesting properties as a result of the broad spectral coverage in the region 350-800 nm. The co-sensitized solar cells based on SPSQ2 + N3 showed the highest short circuit current density of 17.10 mA cm(-2), an open circuit voltage of 0.66 V and a fill factor of 0.73, resulting in the highest power conversion efficiency of 8.2%, which is higher than that of the dye-sensitized solar cells based on the individual SPSQ1 and SPSQ2 dyes. The high power conversion efficiency of SPSQ2 + N3 was ascribed to its good light-harvesting properties, which resulted from its broader incident photon current conversion spectrum than that of the individual dyes. The high electron life time and electron recombination, which were the main causes of the higher efficiency of the device, were successfully analysed and correlated using transient absorption spectrometry and intensity-modulated photovoltage spectrometry.

Socio-economic and demographic factors influencing nutritional status among early childbearing young mothers in Bangladesh.

BACKGROUND: Early childbearing influences women's health. This study aims to examine the effects of socio-demographic factors on nutritional status of early childbearing mothers in Bangladesh based on Body Mass Index (BMI) as the indicator. METHODS: Data was extracted from Bangladesh Demographic and Health Survey (BDHS)-2011. The survey was performed on 17,842 married women aged 15-49. We focused on early childbearing mothers (age ≤ 24, and who had delivered their first child ≤ 20). Mothers who were underweight (BMI ≤ 18.5 kg/m(2)) would be further classified into various grades of chronic energy deficiency (CED): mild (17.0 ≤ BMI < 18.5 kg/m(2)), moderate (16.0 ≤ BMI <17.0 kg/m(2)), and severe (BMI < 16.0 kg/m(2)). Multiple logistic regression model was used to examine the effect of socio-demographic factors on nutritional status. RESULTS: Mean age of the mothers was 20.49 ± 2.37 years (ranged 15-24 years). The prevalence of underweight among early childbearing mothers was 32.1 % (urban 25 % and rural 35.1 %). Most of the underweight mothers had mild (62.2 %) CED, while the remaining had either moderate (25.9 %) or severe (11.9 %) CED. Multiple logistic regression analysis demonstrated that young mothers from rural areas, poor families, and those who were illiterate or with low level of education, working, and married to unemployed husband were at higher risk for being underweight. Young mothers who had non-caesarean delivered, delivered at home, or married at early age and had more than two children were also at higher risk for being underweight. CONCLUSIONS: The prevalence of underweight among early childbearing mothers in Bangladesh is very high (32.1 %), associated with the still common practice of teenage marriage. Education level, wealth index, occupation, place of residence, age at first marriage and parity were important predictors for their nutritional status. The government and non-government organizations should take initiatives to reduce the prevalence of underweight mothers in Bangladesh.

Triflic acid mediated cascade cyclization of aryldiynes for the synthesis of indeno[1,2-c]chromenes: application to dye-sensitized solar cells.

A new triflic acid (TfOH)-mediated cascade cyclization of ortho-anisole-substituted aryldiynes is described for the construction of indeno[1,2-c]chromenes. The cascade cyclization proceeds through an unusual TfOH-induced alkyne-alkyne cyclization followed by nucleophilic attack of the methoxy group on the benzylidene cation, which is completely different to the cyclization of ortho-aniline- or ortho-thioanisole-substituted aryldiynes. A new class of organic dyes with the indeno[1,2-c]chromene framework as both donor and π-linker were synthesized. These compounds exhibit high photovoltaic performances in dye- sensitized solar cells (DSCs).

A comparative study of Ru(II) cyclometallated complexes versus thiocyanated heteroleptic complexes: thermodynamic force for efficient dye regeneration in dye-sensitized solar cells and how low could it be?

Four novel Ru(II) bipyridyl complexes MH12­15 were synthesized and characterized for dye-sensitized solar cells (DSSCs). Their photovoltaic performance including incident photon-to-current conversion efficiency (IPCE), total solar-to-power conversion efficiency (η%) and ground and excited state oxidation potentials and photoelectrochemical properties were evaluated on mesoporous nanocrystalline TiO2 and compared with the benchmark N719-dye under the same experimental conditions. MH12­15 showed stronger MLCT with significantly higher molar extinction coefficient for the lower energy absorption bands at 553 nm (27,500 M(−1) cm(−1)), 554 nm (34,605 M(−1) cm(−1)), 577 nm (23,300 M(−1) cm(−1)), and 582 nm (39,000 M(−1) cm(−1)), respectively, than that of N719 (14,200 M(−1) cm(−1)). The introduction of a cyclometallated ligand in dyes MH14 and 15 improved the optical properties and red-shifts of 24 nm and 28 nm, respectively, compared to the non-cyclometallated analogs MH12 and 13. The red shift in the UV-Vis spectra of MH14 and 15 can be attributed to the destabilization of the HOMO t2g of Ru(II). However, the destabilization of the HOMO furnished an upward shift of the ground state oxidation potentials (GSOPs) of MH14 and 15 at −5.44 eV and −5.36 eV against vacuum, respectively, which resulted in a driving force of only 0.22 and 0.16 eV for regeneration of dyes MH14 and 15, respectively. In the case of NCS analogs, MH12 and 13, the GSOPs, however, were −5.56 and −5.51 eV, respectively, which produced a driving force of more than 0.25 eV for dye regeneration. The nanosecond transient absorbance measurements showed that the time needed for the oxidized forms of MH12­MH15 to regenerate the neutral dye is 6 µs, 4 µs, 13 µs and 18 µs, respectively, compared to N719 (2.3 µs). These kinetic data confirmed that the weak thermodynamic force, small negative free energy (−ΔG), for regeneration of MH14 and 15 neutral dyes makes the dye regeneration process kinetically sluggish, which contributed significantly to the loss of both photocurrent and photovoltage. This study clearly elucidated that although cyclometallation may produce significantly better light harvesting, the driving force of less than 0.25 eV is not sufficiently enough for effective dye regeneration.

More stable and more efficient alternatives of Z-907: carbazole-based amphiphilic Ru(II) sensitizers for dye-sensitized solar cells.

Here we report two novel amphiphilic Ru(II) heteroleptic bipyridyl complexes, HD-14 and HD-15, compared to previously reported NCSU-10. We have combined the strong electron donor characteristics of carbazole and the hydrophobic nature of different long alkyl chains, C7, C18 and C2 (NCSU-10), tethered to N-carbazole to study their influence on photocurrent, photovoltage and long term stability for dye-sensitized solar cells. Photon harvesting efficiency and electron donating characteristics of carbazole-based ancillary ligands were found to be unaffected by different alkyl chain lengths. However, a slight drop in the Voc of HD-14 and HD-15 was observed compared to that of NCSU-10. It was found by nanosecond flash photolysis transient absorption (TA) measurements that the faster the dye regeneration the higher the photocurrent density response, and the dye regeneration time was found to be 2.6, 3.6, and 3.7 µs for HD-14, HD-15, and N719 dyes, respectively. The difference in the amplitude of the transient absorption (TA) signal of the oxidized dye as measured by femtosecond TA studies is in excellent agreement with the photocurrent generated, which was in the following order HD-14 > HD-15 > N719. Under 1000 h light soaking conditions, HD-15 maintained up to 98% (only 2% loss) of the initial power conversion efficiency compared to 8% loss for HD-14 and 22% loss in the power conversion efficiency for NCSU-10. HD-15 was strikingly stable to light soaking conditions when employed in the presence of an ionic liquid electrolyte, which paves the way for widespread applications of dye-sensitized solar cells with long term stability. The total power conversion efficiency (η) was 9.27% for HD-14 and 9.17% for HD-15 compared to 8.92% for N719.