Gold(III), Mercury(II), and Palladium(II) Complexes of a Series of Isomeric Bis(mono- and dialkoxyphenyl)pyridines: Introduction of Gold through Transmetalation and Catalysis.

A series of isomeric bis-2,6-(monoalkoxyphenyl)pyridine and bis-2,6-(dialkoxyphenyl)pyridine ligands were synthesized and characterized. In order to prepare their chlorogold(III) complexes, intermediate chloromercury(II) complexes were first prepared, but unlike observations from previous studies where they were obtained impure and at best in moderate yield, here pure complexes were synthesized, many in rather high yields. Depending on the substitution pattern of the alkoxy chains on the ligands, mono- and/or dimercurated complexes were obtained, characterized by 1H, 13C{1H}, and 199Hg NMR spectroscopy as well as, in several cases, by X-ray crystallography. Factors that may explain this unusual reactivity are discussed. In most cases, transmetalation to the related chlorogold(III) complex proceeded smoothly, although lower yields were obtained when starting from doubly mercurated precursors. Prompted by the propensity of these ligands to mercurate, attempts were made to effect direct auration, but none was successful. However, dimeric, orthometalated complexes of palladium(II) could be prepared and were also amenable to transmetalation to the chlorogold(III) complex, providing for a mercury-free synthesis.

Correction: On the mercuration, palladation, transmetalation and direct auration of a C

Correction for 'On the mercuration, palladation, transmetalation and direct auration of a C^N^C pincer ligand' by Alice Jane McEllin et al., Dalton Trans., 2023, 52, 872-876, https://doi.org/10.1039/d2dt04114f.

Liquid-crystalline circularly polarised fluorescent emitters with a high luminescence dissymmetry factor.

Chiral liquid-crystalline emitters based on 9,9-dimethyl-10-(4-(phenylsulfonyl)phenyl)-9,10-dihydroacridine and a functionalised binaphthol show smectic liquid crystal phases and circularly polarised blue fluorescence with a high luminescence dissymmetry factor |glum| of 0.13. Solution-processable organic light-emitting diodes (OLEDs) based on the enantiomers were explored.

Length-weight relationship for Potamotrygon wallacei (Carvalho, Rosa and Araújo, 2016) caught in the middle Negro River, Barcelos, Brazilian Amazon

Abstract This research aimed to estimate the length-weight ratio (LWR) of the stingray Potamotrygon wallacei, known locally as the cururu, which was caught in streams and lakes in the middle Negro River region, Amazonas, Brazil. The stingrays were captured during the night (from 11 pm to 1 am) near the shores of streams and lakes, through active search using wooden canoes, head lanterns and scoop nets. The samplings were carried out in November 2017 (5 days), February (8 days), March (3 days) and April (2 days) of 2018, totaling 18 days of sampling. The total fresh weight was measured to 0.1 g of accuracy and the disc width to 0.1 cm accuracy. The parameters a and b of the equation W=a.DWb were estimated. This study provides new maximum length data for the cururu stingray.

Resumo Esta pesquisa teve como objetivo estimar a relação peso-comprimento (LWR) da arraia Potamotrygon wallacei, conhecida localmente como cururu, que foi capturada em igarapés e lagos na região do médio Rio Negro, Amazonas, Brasil. As arraias foram capturadas durante a noite (das 23h-1h) nas margens dos igarapés e lagos, por meio de busca ativa utilizando canoas de madeira, lanternas de cabeça e puçás. As coletas foram realizadas nos meses de novembro de 2017 (5 dias), fevereiro (8 dias), março (3 dias) e abril (2 dias) de 2018, totalizando 18 dias de amostragem. Foram medidos o peso fresco total com precisão de 0,01 g e a largura do disco com precisão de 0,1 cm. Os parâmetros a e b da equação W= a.DWb foram estimados. Este estudo prover novos dados de comprimento máximo para a arraia cururu.

Liquid-crystalline circularly polarised TADF emitters for high-efficiency, solution-processable organic light-emitting diodes.

Achieving a high emission efficiency and a large luminescence asymmetry factor (glum) in a single molecule exhibiting circularly polarised thermally activated delayed fluorescence (CP-TADF) remains a formidable challenge. In this work, a proof-of-concept, liquid-crystalline CP-TADF molecule is proposed to realise high glum by taking advantage of the order inherent in liquid crystals. Employing a chiral dinaphthol-based CP-TADF molecule as the emissive unit, a pair of liquid-crystalline CP-TADF molecules (R/S-4) is synthesised via the introduction of six mesogenic moieties. The enantiomers show intense emission at about 520 nm which has clear TADF and liquid-crystalline characteristics. Both enantiomers display symmetrical electronic circular dichroism (CD) and circular polarisation luminescence (CPL) signals as thin films. Impressively, relatively large glum values of 0.11 are realised for the films. Solution-processed devices were fabricated using R/S-4 as the dopants, with the TADF molecule CzAcSF as the sensitiser. The OLEDs so prepared show a very high maximum external quantum efficiency of 21.2%, revealing a novel strategy for realising large glum values in CP-TADF.

Length-weight relationship for Potamotrygon wallacei (Carvalho, Rosa and Araújo, 2016) caught in the middle Negro River, Barcelos, Brazilian Amazon / Relação peso-comprimento de Potamotrygon wallacei (Carvalho, Rosa e Araújo, 2016) capturada no médio Rio Negro, Barcelos, Amazônia Brasileira

Abstract This research aimed to estimate the length-weight ratio (LWR) of the stingray Potamotrygon wallacei, known locally as the cururu, which was caught in streams and lakes in the middle Negro River region, Amazonas, Brazil. The stingrays were captured during the night (from 11 pm to 1 am) near the shores of streams and lakes, through active search using wooden canoes, head lanterns and scoop nets. The samplings were carried out in November 2017 (5 days), February (8 days), March (3 days) and April (2 days) of 2018, totaling 18 days of sampling. The total fresh weight was measured to 0.1 g of accuracy and the disc width to 0.1 cm accuracy. The parameters a and b of the equation W=a.DWb were estimated. This study provides new maximum length data for the cururu stingray.

Resumo Esta pesquisa teve como objetivo estimar a relação peso-comprimento (LWR) da arraia Potamotrygon wallacei, conhecida localmente como cururu, que foi capturada em igarapés e lagos na região do médio Rio Negro, Amazonas, Brasil. As arraias foram capturadas durante a noite (das 23h-1h) nas margens dos igarapés e lagos, por meio de busca ativa utilizando canoas de madeira, lanternas de cabeça e puçás. As coletas foram realizadas nos meses de novembro de 2017 (5 dias), fevereiro (8 dias), março (3 dias) e abril (2 dias) de 2018, totalizando 18 dias de amostragem. Foram medidos o peso fresco total com precisão de 0,01 g e a largura do disco com precisão de 0,1 cm. Os parâmetros a e b da equação W= a.DWb foram estimados. Este estudo prover novos dados de comprimento máximo para a arraia cururu.

Development of an acute ovine model of polycystic ovaries to assess the effect of ovarian denervation.

Introduction: Polycystic ovary syndrome (PCOS) seems to be associated with increased ovarian sympathetic nerve activity and in rodent models of PCOS reducing the sympathetic drive to the ovary, through denervation or neuromodulation, improves ovulation rate. We hypothesised that sympathetic nerves work with gonadotropins to promote development and survival of small antral follicles to develop a polycystic ovary phenotype. Methods: Using a clinically realistic ovine model we showed a rich sympathetic innervation to the normal ovary and reinnervation after ovarian transplantation. Using needlepoint diathermy to the nerve plexus in the ovarian vascular pedicle we were able to denervate the ovary resulting in reduced intraovarian noradrenaline and tyrosine hydroxylase immunostained sympathetic nerves. We developed an acute polycystic ovary (PCO) model using gonadotrophin releasing hormone (GnRH) agonist followed infusion of follicle stimulating hormone (FSH) with increased pulsatile luteinising hormone (LH). This resulted in increased numbers of smaller antral follicles in the ovary when compared to FSH infusion suggesting a polycystic ovary. Results: Denervation had no effect of the survival or numbers of follicles in the acute PCO model and did not impact on ovulation, follicular and luteal hormone profiles in a normal cycle. Discussion: Although the ovary is richly inervated we did not find evidence for a role of sympathetic nerves in ovarian function or small follicle growth and survival.

Increased blood meal size and feeding frequency compromise Aedes aegypti midgut integrity and enhance dengue virus dissemination.

Aedes aegypti is a highly efficient vector for numerous pathogenic arboviruses including dengue virus (DENV), Zika virus, and yellow fever virus. This efficiency can in part be attributed to their frequent feeding behavior. We previously found that acquisition of a second, full, non-infectious blood meal could accelerate virus dissemination within the mosquito by temporarily compromising midgut basal lamina integrity; however, in the wild, mosquitoes are often interrupted during feeding and only acquire partial or minimal blood meals. To explore the impact of this feeding behavior further, we examined the effects of partial blood feeding on DENV dissemination rates and midgut basal lamina damage in Ae. aegypti. DENV-infected mosquitoes given a secondary partial blood meal had intermediate rates of dissemination and midgut basal lamina damage compared to single-fed and fully double-fed counterparts. Subsequently, we evaluated if basal lamina damage accumulated across feeding episodes. Interestingly, within 24 hours of feeding, damage was proportional to the number of blood meals imbibed; however, this additive effect returned to baseline levels by 96 hours. These data reveal that midgut basal lamina damage and rates of dissemination are proportional to feeding frequency and size, and further demonstrate the impact that mosquito feeding behavior has on vector competence and arbovirus epidemiology. This work has strong implications for our understanding of virus transmission in the field and will be useful when designing laboratory experiments and creating more accurate models of virus spread and maintenance.

Recent advances in the understanding of tubal ectopic pregnancy.

Ectopic pregnancy (EP) is described as the implantation of an embryo outside the normal uterine cavity. It most commonly occurs in the fallopian tube, hence termed a tubal ectopic pregnancy (tEP). It is a gynaecological emergency and remains the leading cause of direct maternal mortality related to the first trimester of pregnancy worldwide. This article explores the emergence of additional risk factors for tEP, showing new evidence for identifying patient risk factors and highlighting potential areas of research. Additionally, we discuss the up-to-date patient-centred approach for the diagnosis, management and counselling of patients with tEP and ongoing clinical trials for the improvement of medical management.

Comparison of acarological risk metrics derived from active and passive surveillance and their concordance with tick-borne disease incidence.

Tick-borne diseases continue to threaten human health across the United States. Both active and passive tick surveillance can complement human case surveillance, providing spatio-temporal information on when and where humans are at risk for encounters with ticks and tick-borne pathogens. However, little work has been done to assess the concordance of the acarological risk metrics from each surveillance method. We used data on Ixodes scapularis and its associated human pathogens from Connecticut (2019-2021) collected through active collections (drag sampling) or passive submissions from the public to compare county estimates of tick and pathogen presence, infection prevalence, and tick abundance by life stage. Between the surveillance strategies, we found complete agreement in estimates of tick and pathogen presence, high concordance in infection prevalence estimates for Anaplasma phagocytophilum, Borrelia burgdorferi sensu stricto, and Babesia microti, but no consistent relationships between actively and passively derived estimates of tick abundance or abundance of infected ticks by life stage. We also compared nymphal metrics (i.e., pathogen prevalence in nymphs, nymphal abundance, and abundance of infected nymphs) with reported incidence of Lyme disease, anaplasmosis, and babesiosis, but did not find any consistent relationships with any of these metrics. The small spatial and temporal scale for which we had consistently collected active and passive data limited our ability to find significant relationships. Findings are likely to differ if examined across a broader spatial or temporal coverage with greater variation in acarological and epidemiological outcomes. Our results indicate similar outcomes between some actively and passively derived tick surveillance metrics (tick and pathogen presence, pathogen prevalence), but comparisons were variable for abundance estimates.

Measurement of tooth displacement.

The periodontium is a biological structure that supports the tooth in the jaw and behave as a developmental, biological, and functional unit. Teeth may be considered to be 'suspended' in their tooth sockets which provides teeth the ability to move in response to an applied load. In terms of the protection the suspension effect of the periodontal ligament may offer dental restorations, movement in an axial direction is of interest. No device or system to measure this movement is readily available, thus a novel approach had to be developed to address the questions of this research. The device developed allowed images to be taken of the participants teeth before, during and after a participant bit down on the tooth and used to measure the displacement of the tooth in image processing software. Average maximum tooth displacement from all participants of 73.8 µm (sd = 22.5 µm) were recorded. Longer application time of bite force was associated with greater cumulative tooth displacement, for a given level of force, and female participants experienced approximately 2 µm more displacement per Newton than males. The device and methods utilised in this study has shown good potential as a measurement protocol for measurement of vertical tooth movements in vivo. The response to load the teeth in this study has shown, highlighted the visco-elastic properties of the periodontal ligament and the amount of movement recorded supports the protection that controlled tooth movement offers teeth.

Understanding the Liquid Structure in Mixtures of Ionic Liquids with Semiperfluoroalkyl or Alkyl Chains.

By mixing ionic liquids (ILs), it is possible to fine-tune their bulk and interfacial structure. This alters their physical properties and solvation behavior and is a simple way to prepare a collection of ILs whose properties can be tuned to optimize a specific application. In this study, mixtures of perfluorinated and alkylated ILs have been prepared, and links between composition, properties, and nanostructure have been investigated. These different classes of ILs vary substantially in the flexibility and polarizability of their chains. Thus, a range of useful structural and physical property variations are accessible through mixing that will expand the library of IL mixtures available in an area that to this point has received relatively little attention. In the experiments presented herein, the physical properties and bulk structure of mixtures of 1-methyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide [C8MIM][Tf2N] and 1-(1H,1H,2H,2H-perfluorooctyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C8MIM-F13][Tf2N] have been prepared. The bulk liquid structure was investigated using a combination of small-angle X-ray and neutron scattering (SAXS and SANS, respectively) experiments in combination with atomistic molecular dynamics simulations and the measurement of density and viscosity. We observed that the addition of [C8MIM-F13][Tf2N] to [C8MIM][Tf2N] causes changes in the nanostructure of the IL mixtures that are dependent on composition so that variation in the characteristic short-range correlations is observed as a function of composition. Thus, while the length scales associated with the apolar regions (polar non-polar peak─PNPP) increase with the proportion of [C8MIM-F13][Tf2N] in the mixtures, perhaps surprisingly given the greater volume of the fluorocarbon chains, the length scale of the charge-ordering peak decreases. Interestingly, consideration of the contact peak shows that its origins are both in the direct anion···cation contact length scale and the nature (and hence volume) of the chains appended to the imidazolium cation.

Superthermal Al Atoms as a Reactive-Atom Probe of Fluorinated Surfaces.

We demonstrate a proof-of-concept of a new analytical technique to measure relative F atom exposure at the surfaces of fluorinated materials. The method is based on reactive-atom scattering (RAS) of Al atoms, produced by pulsed laser ablation of solid Al at 532 nm. The properties of the incident ground-state Al were characterized by laser-induced fluorescence (LIF); at typical ablation fluences, the speed distribution is approximately Maxwellian at ∼45000 K, with a most-probable kinetic energy of 187 kJ mol-1 and a mean of 560 kJ mol-1 When these Al atoms impact the surfaces of perfluorinated solids (poly(tetrafluorethylene), PTFE) or liquids (perfluoropolyether, PFPE), gas-phase AlF products are clearly detectable by LIF on the AlF A-X band. Quantitative AlF yields were compared for a small representative set of a widely studied family of ionic liquids based on the common 1-alkyl-3-methylimidazolium ([Cnmim]+) cation. Yields of (1.9 ± 0.2):1 were found from [C2mim][Tf2N] and [C8mim][Tf2N], containing the common fluorinated bis(trifluoromethylsulfonyl)imide anion ([Tf2N]-). This is in quantitative agreement with previous independent low-energy ion scattering (LEIS) measurements and consistent with other independent results indicating that the longer cationic alkyl chains cover a larger fraction of the liquid surface and hence reduce anion exposure. The expected null result was obtained for the ionic liquid [C2mim][EtSO4] which contains no fluorine. These results open the way for further characterization and the potential application of this new variant of the RAS-LIF method.

Subsequent pregnancy outcomes among women with tubal ectopic pregnancy treated with methotrexate.

Lay summary: An ectopic pregnancy occurs when an embryo implants outside of the uterus, usually in a fallopian tube. When detected early, treatment is often with a medication called methotrexate. When methotrexate does not work, surgery is required. A recent clinical trial of ectopic pregnancy treatment (called GEM3) found that adding a drug called gefitinib to methotrexate did not reduce the need for surgery. We have used data from the GEM3 trial, combined with data collected 12 months after the trial finished, to investigate post-methotrexate pregnancy outcomes. We found no difference in pregnancy rates, pregnancy loss rates and recurrent ectopic pregnancy rates between those treated medically only and those who subsequently also needed surgery. The surgical technique used also did not affect pregnancy rates. This research provides reassurance that women with ectopic pregnancies treated medically who need surgery have similar post-treatment pregnancy outcomes to those treated successfully medically.

Early (Days 1-4) post-treatment serum hCG level changes predict single-dose methotrexate treatment success in tubal ectopic pregnancy.

STUDY QUESTION: What is the capacity of the change between Day 1 and Day 4 post-treatment serum human chorionic gonadotropin (hCG) levels for predicting single-dose methotrexate treatment success in tubal ectopic pregnancy? SUMMARY ANSWER: Any fall in Days 1-4 serum hCG signified an 85% (95% CI 76.8-90.6) likelihood of treatment success for women with tubal ectopic pregnancy (initial hCG of ≥1000 and ≤5000 IU/l) managed with single-dose methotrexate. WHAT IS KNOWN ALREADY: For those with tubal ectopic pregnancy managed by single-dose methotrexate, current guidelines advocate intervention if Days 4-7 hCG fails to fall by >15%. The trajectory of hCG over Days 1-4 has been proposed as an early indicator that predicts treatment success, allowing early reassurance for women. However, almost all prior studies of Days 1-4 hCG changes have been retrospective. STUDY DESIGN, SIZE, DURATION: This was a prospective cohort study of women with tubal ectopic pregnancy (pre-treatment hCG of ≥1000 and ≤5000 IU/l) managed with single-dose methotrexate. The data were derived from a UK multicentre randomized controlled trial of methotrexate and gefitinib versus methotrexate and placebo for treatment of tubal ectopic pregnancy (GEM3). For this analysis, we include data from both treatment arms. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants were categorized according to single-dose methotrexate treatment success or failure. Treatment success for this analysis was defined as complete and uneventful resolution of tubal ectopic pregnancy to serum hCG <30 IU/l following single-dose methotrexate treatment without additional treatment. Patient characteristics of the treatment success and failure groups were compared. Changes in Days 1-4, 1-7, and 4-7 serum hCG were evaluated as predictors of treatment success through receiver operating characteristic curve analysis. Test performance characteristics were calculated for percentage change ranges and thresholds including optimal classification thresholds. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 322 women with tubal ectopic pregnancy were treated with single-dose methotrexate. The overall single-dose methotrexate treatment success rate was 59% (n = 189/322). For any fall in serum hCG on Days 1-4, likelihood ratios were >3, while for any fall of serum hCG >20% on Days 1-7, likelihood ratios reached 5. Any rise of serum hCG on Days 1-7 and 4-7 strongly reduced the chance of success. Any fall in Days 1-4 hCG predicted single-dose methotrexate treatment success with a sensitivity of 58% and specificity 84%, resulting in positive and negative predictive values of 85% and 57%, respectively. Any rise in Days 1-4 serum hCG <18% was identified as an optimal test threshold that predicted treatment success with 79% sensitivity and 74% specificity, resulting in 82% positive predictive value and 69% negative predictive value. LIMITATIONS, REASONS FOR CAUTION: Our findings may be limited by intervention bias resulting from existing guidelines which influences evaluation of hCG changes reliant on Day 7 serum hCG levels. WIDER IMPLICATIONS OF THE FINDINGS: Examining a large prospective cohort, we show the value of Days 1-4 serum hCG changes in predicting single-dose methotrexate treatment success in tubal ectopic pregnancy. We recommend that clinicians provide early reassurance to women who have a fall or only a modest (<18%) rise in Days 1-4 serum hCG levels, that their treatment will likely be effective. STUDY FUNDING/COMPETING INTEREST(S): This project was supported by funding from the Efficacy and Mechanism Evaluation programme, a Medical Research Council and National Institute for Health Research partnership (grant reference number 14/150/03). A.W.H. has received honoraria for consultancy for Ferring, Roche, Nordic Pharma and AbbVie. W.C.D. has received honoraria from Merck and Guerbet and research funding from Galvani Biosciences. L.H.R.W. has received research funding from Roche Diagnostics. B.W.M. is supported by a NHMRC Investigator grant (GNT1176437). B.W.M. also reports consultancy for ObsEva and Merck and travel support from Merck. The other authors declare no competing interests. TRIAL REGISTRATION NUMBER: This study is a secondary analysis of the GEM3 trial (ISRCTN Registry ISRCTN67795930).

The impact of COVID-19 on the assessment and management of ectopic pregnancies.

Lay Summary: During the COVID-19 pandemic, the public delayed seeking medical help, which may have affected the impact of having an ectopic pregnancy. An ectopic pregnancy is when pregnancy tissue grows outside its normal position in the womb, and it can be life-threatening. It can be treated by non-surgical or surgical options, and any delay in seeking help can reduce the options for treatment and increase the need for more urgent management. We wanted to assess whether there were differences in the presentation and management of ectopic pregnancies in a major teaching hospital between 2019 (pre-COVID-19) and 2021 (COVID-19 period). We found that the pandemic did not cause a delay in seeking medical help or cause worse outcomes. In fact, immediate surgical treatment and time in the hospital were less during COVID-19, perhaps because of a desire to avoid admission to hospital. One outcome of COVID-19 is reassurance that we can safely use more non-surgical treatments for ectopic pregnancies.

Combination of gefitinib and methotrexate to treat tubal ectopic pregnancy (GEM3): a multicentre, randomised, double-blind, placebo-controlled trial.

BACKGROUND: Tubal ectopic pregnancies can cause substantial morbidity or even death. Current treatment is with methotrexate or surgery. Methotrexate treatment fails in approximately 30% of women who subsequently require rescue surgery. Gefitinib, an epidermal growth factor receptor inhibitor, might improve the effects of methotrexate. We assessed the efficacy of oral gefitinib with methotrexate, versus methotrexate alone, to treat tubal ectopic pregnancy. METHODS: We performed a multicentre, randomised, double-blind, placebo-controlled trial across 50 UK hospitals. Participants diagnosed with tubal ectopic pregnancy were administered a single dose of intramuscular methotrexate (50 mg/m2) and randomised (1:1 ratio) to 7 days of additional oral gefitinib (250 mg daily) or placebo. The primary outcome, analysed by intention to treat, was surgical intervention to resolve the ectopic pregnancy. Secondary outcomes included time to resolution of ectopic pregnancy and serious adverse events. This trial is registered at the ISRCTN registry, ISCRTN 67795930. FINDINGS: Between Nov 2, 2016, and Oct 6, 2021, 328 participants were allocated to methotrexate and gefitinib (n=165) or methotrexate and placebo (n=163). Three participants in the placebo group withdrew. Surgical intervention occurred in 50 (30%) of 165 participants in the gefitinib group and in 47 (29%) of 160 participants in the placebo group (adjusted risk ratio 1·15, 95% CI 0·85 to 1·58; adjusted risk difference -0·01, 95% CI -0·10 to 0·09; p=0·37). Without surgical intervention, median time to resolution was 28·0 days in the gefitinib group and 28·0 days in the placebo group (subdistribution hazard ratio 1·03, 95% CI 0·75 to 1·40). Serious adverse events occurred in five (3%) of 165 participants in the gefitinib group and in six (4%) of 162 participants in the placebo group. Diarrhoea and rash were more common in the gefitinib group. INTERPRETATION: In women with a tubal ectopic pregnancy, adding oral gefitinib to parenteral methotrexate does not offer clinical benefit over methotrexate and increases minor adverse reactions. FUNDING: National Institute of Health Research.

On the mercuration, palladation, transmetalation and direct auration of a C

The C^N^C ligand 2,6-bis(2,3-dialkoxyphenyl)pyridine forms dimercury and orthopalladated complexes, both of which may be transmetallated to gold(III) complexes; the gold complexes may also be formed directly in a Rh(III)-catalysed process, hence it is possible to circumvent the use of organomercury intermediates in the synthesis of this important class of compound.

Construction and performance of OLED devices prepared from liquid-crystalline TADF materials.

The device performance is reported for three compounds which show both thermally activated delayed fluorescence and liquid crystallinity, and use the donor 3,6-bis(3,4-didodecyloxyphenyl)carbazole. Two of the compounds, whose photophysics were reported previously, are based on a terephthalonitrile acceptor. A third and new compound is based on an isophthalonitrile acceptor and shows a more temperature-accessible mesophase and enhanced solution emission quantum yield. Two of the compounds show device external quantum efficiencies of between 2-3% and exhibit very small efficiency roll off. The responses are evaluated in terms of the specific nature of the materials.

The novel use of urinary androgens to optimise detection of the fertile window in giant pandas.

Abstract: Giant pandas are mono-estrus seasonal breeders, with the breeding season typically occurring in the spring. Successful fertilization is followed by an embryonic diapause, of variable length, with birth in the late summer/autumn. There is a need for additional understanding of giant panda reproductive physiology, and the development of enhanced biomarkers for impending proestrus and peak fertility. We aimed to determine the utility of non-invasive androgen measurements in the detection of both proestrus and estrus. Urine from 20 cycles (-40 days to +10 days from peak estrus) from 5 female giant pandas was analyzed for estrogen, progestogens and androgens (via testosterone and DHEA assays), and hormone concentrations were corrected against urinary specific gravity. Across proestrus, estrogens increased while progestogens and androgens decreased - at the point of entry into proestrus, androgens (as detected by the testosterone assay) decreased prior to progestogens and gave 4 days advanced warning of proestrus. At the time of peak estrus, androgens (as detected by the DHEA assay) were significantly increased at the time of the decrease in estrogen metabolites from the peak, acting as an alternative confirmatory indicator of the fertile window. This novel finding allows for enlargement of the preparative window for captive breeding and facilitates panda management within breeding programmes. Androgens allow an enhanced monitoring of giant panda estrus, not only advancing the warning of impending proestrus, but also prospectively identifying peak fertility. Lay summary: Giant pandas have one chance at pregnancy per year. The 2-day fertile window timing varies by year and panda. This is monitored by measuring the level of estrogens in the urine, which increase, indicating an upcoming fertile period. After 1-2 weeks of increase, estrogens peak and fall, marking the optimal fertile time. We tested other hormones to see if we can predict the fertile window in advance, and the specific fertile time with more accuracy. In 20 breeding seasons from 5 females, we found androgens, usually thought of as male hormones, had an important role. Testosterone gives 4 days advanced warning of estrogens increasing. DHEA identified peak estrogen and the fertile time before needing to see a confirmed decrease in estrogen itself. Therefore, androgens help improve monitoring of the giant panda breeding season, giving early warning of fertility, key in facilitating captive breeding and giant panda conservation.