Photo-Cross-Linked Fullerene-Based Hole Transport Material for Moisture-Resistant Regular Fullerene Sandwich Perovskite Solar Cells.

Despite the high efficiencies currently achieved with perovskite solar cells (PSCs), the need to develop stable devices, particularly in humid conditions, still remains. This study presents the synthesis of a novel photo-cross-linkable fullerene-based hole transport material named FT12. For the first time, the photo-cross-linking process is applied to PSCs, resulting in the preparation of photo-cross-linked FT12 (PCL FT12). Regular PSCs based on C60-sandwich architectures were fabricated using FT12 and PCL FT12 as dopant-free hole transport layers (HTLs) and compared to the reference spiro-OMeTAD. The photovoltaic results demonstrate that both FT12 and PCL FT12 significantly outperform pristine spiro-OMeTAD regarding device performance and stability. The comparison between devices based on FT12 and PCL FT12 demonstrates that the photo-cross-linking process enhances device efficiency. This improvement is primarily attributed to enhanced charge extraction, partial oxidation of the HTL, increased hole mobility, and improved layer morphology. PCL FT12-based devices exhibit improved stability compared to FT12 devices, primarily due to the superior moisture resistance achieved through photo-cross-linking.

Multicentre randomised trial of screening with sFlt1/PlGF and planned delivery to prevent pre-eclampsia at term: protocol of the PE37 study.

INTRODUCTION: Pre-eclampsia affects ~5%-7% of pregnancies. Although improved obstetric care has significantly diminished its associated maternal mortality, it remains a leading cause of maternal morbidity and mortality in the world. Term pre-eclampsia accounts for 70% of all cases and a large proportion of maternal-fetal morbidity related to this condition. Unlike in preterm pre-eclampsia, the prediction and prevention of term pre-eclampsia remain unsolved. Previously proposed approaches are based on combined third-trimester screening and/or prophylactic drugs, but these policies are unlikely to be widely implementable in many world settings. Recent evidence shows that the soluble fms-like tyrosine kinase-1 (s-Flt-1) to placental growth factor (PlGF) ratio measured at 35-37 weeks' gestation predicts term pre-eclampsia with an 80% detection rate. Likewise, recent studies demonstrate that induction of labour beyond 37 weeks is safe and well accepted by women. We hypothesise that a single-step universal screening for term pre-eclampsia based on sFlt1/PlGF ratio at 35-37 weeks followed by planned delivery beyond 37 weeks reduces the prevalence of term pre-eclampsia without increasing the caesarean section rates or worsening the neonatal outcomes. METHODS AND ANALYSIS: We propose an open-label randomised clinical trial to evaluate the impact of a screening of term pre-eclampsia with the sFlt-1/PlGF ratio followed by planned delivery in asymptomatic nulliparous women at 35-37 weeks. Women will be assigned 1:1 to revealed (sFlt-1/PlGF known to clinicians) versus concealed (unknown) arms. A cut-off of >90th centile is used to define the high risk of subsequent pre-eclampsia and offer planned delivery from 37 weeks. The efficacy variables will be analysed and compared between groups primarily following an intention-to-treat approach, by ORs and their 95% CI. This value will be computed using a Generalised Linear Mixed Model for binary response (study group as fixed effect and the centre as intercept random effect). ETHICS AND DISSEMINATION: The study is conducted under the principles of Good Clinical Practice. This study was accepted by the Clinical Research Ethics Committee of Hospital Clinic Barcelona on 20 November 2020. Subsequent approval by individual ethical committees and competent authorities was granted. The study results will be published in peer-reviewed journals and disseminated at international conferences. TRIAL REGISTRATION NUMBER: NCT04766866.

Anti-SARS-CoV-2-specific antibodies in human breast milk following SARS-CoV-2 infection during pregnancy: a prospective cohort study.

BACKGROUND: While the presence of SARS-CoV-2 in human breast milk is contentious, anti-SARS-CoV-2 antibodies have been consistently detected in human breast milk. However, it is uncertain when and how long the antibodies are present. METHODS: This was a prospective cohort study including all consecutive pregnant women with confirmed SARS-CoV-2 infection during pregnancy, recruited at six maternity units in Spain and Hong Kong from March 2020 to March 2021. Colostrum (day of birth until day 4 postpartum) and mature milk (day 7 postpartum until 6 weeks postpartum) were prospectively collected, and paired maternal blood samples were also collected. Colostrum samples were tested with rRT-PCR-SARS-CoV-2, and skimmed acellular milk and maternal sera were tested against SARS-CoV-2 specific immunoglobulin M, A, and G reactive to receptor binding domain of SARS-CoV-2 spike protein 1 to determine the presence of immunoglobulins. Then, we examined how each immunoglobulin type in the colostrum was related to the time of infection by logistic regression analysis, the concordance between these immunoglobulins in the colostrum, maternal serum, and mature milk by Cohen's kappa statistic, and the relationship between immunoglobulin levels in mature milk and colostrum with McNemar. RESULTS: One hundred eighty-seven pregnant women with confirmed SARS-CoV-2 infection during pregnancy or childbirth were recruited and donated the milk and blood samples. No SARS-CoV-2 was found in the human breast milk. Immunoglobulin A, G, and M were present in 129/162 (79·6%), 5/163 (3·1%), and 15/76 (19·7%) colostrum samples and in 17/62 (27·42%), 2/62 (3·23%) and 2/62 (3·23%) mature milk samples, respectively. Immunoglobulin A was the predominant immunoglobulin found in breast milk, and its levels were significantly higher in the colostrum than in the mature milk (p-value < 0.001). We did not find that the presence of immunoglobulins in the colostrum was associated with their presence in maternal, the severity of the disease, or the time when the infection had occurred. CONCLUSIONS: Since anti-SARS-CoV-2 antibodies are found in the colostrum irrespective of the time of infection during pregnancy, but the virus itself is not detected in human breast milk, our study found no indications to withhold breastfeeding, taking contact precautions when there is active disease.

p-Type Functionalized Carbon Nanohorns and Nanotubes in Perovskite Solar Cells.

The incorporation of p-type functionalized carbon nanohorns (CNHs) in perovskite solar cells (PSCs) and their comparison with p-type functionalized single- and double-walled carbon nanotubes (SWCNTs and DWCNTs) are reported in this study for the first time. These p-type functionalized carbon nanomaterial (CNM) derivatives were successfully synthesized by [2 + 1] cycloaddition reaction with nitrenes formed from triphenylamine (TPA) and 9-phenyl carbazole (Cz)-based azides, yielding CNHs-TPA, CNHs-Cz, SWCNTs-Cz, SWCNTs-TPA, DWCNTs-TPA, and DWCNTs-Cz. These six novel CNMs were incorporated into the spiro-OMeTAD-based hole transport layer (HTL) to evaluate their impact on regular mesoporous PSCs. The photovoltaic results indicate that all p-type functionalized CNMs significantly improve the power conversion efficiency (PCE), mainly by enhancing the short-circuit current density (Jsc) and fill factor (FF). TPA-functionalized derivatives increased the PCE by 12-17% compared to the control device without CNMs, while Cz-functionalized derivatives resulted in a PCE increase of 4-8%. Devices prepared with p-type functionalized CNHs exhibited a slightly better PCE compared with those based on SWCNTs and DWCNTs derivatives. The increase in hole mobility of spiro-OMeTAD, additional p-type doping, better energy alignment with the perovskite layer, and enhanced morphology and contact interface play important roles in enhancing the performance of the device. Furthermore, the incorporation of p-type functionalized CNMs into the spiro-OMeTAD layer increased device stability by improving the hydrophobicity of the layer and enhancing the hole transport across the MAPI/spiro-OMeTAD interface. After 28 days under ambient conditions and darkness, TPA-functionalized CNMs maintained the performance of the device by over 90%, while Cz-functionalized CNMs preserved it between 75 and 85%.

Pravastatin reduces plasma levels of extracellular vesicles in pregnancies at high risk of term preeclampsia.

Introduction: Elevated plasma levels of extracellular vesicles have been associated with impaired placentation, angiogenesis imbalance, intravascular inflammation, and endothelial dysfunction in women with preeclampsia, thus suggesting that circulating vesicles may be a good therapeutic target for the treatment of the disease. Recently, statins have been considered a potential treatment for the prevention of preeclampsia because of their pleiotropic effects, including the improvement of endothelial dysfunction and inhibition of inflammatory responses. However, the effects of these drugs on circulating vesicles concentration in women at risk of preeclampsia have not been established. Herein, we aimed to assess the effects of pravastatin on circulating extracellular vesicle generation in women at high risk of term preeclampsia. Methods: In a sample of 68 singleton pregnant women participating in the multicenter, double-blind, placebo-controlled STATIN trial (Nº EducraCT 2016-005206-19 ISRCTN), 35 women received a placebo and 33 women received a 20 mg/day dose of pravastatin for approximately 3 weeks (from 35 to 37 weeks of gestation until delivery). Large extracellular vesicles were characterized and quantified by flow cytometry using annexin V and cell-specific antibodies directed against platelet, endothelial, leukocyte, and syncytiotrophoblast cell surface markers. Results: In women who received the placebo, a significant increase in the plasma levels of large extracellular vesicles from platelets (34%, p < 0.01), leukocytes (33%, p < 0.01), monocytes (60%, p < 0.01), endothelial cells (40%, p < 0.05), and syncytiotrophoblast cells (22%, p < 0.05) were observed. However, treatment with pravastatin significantly reduced the plasma levels of large extracellular vesicles from platelets (42%, p < 0.001), leukocytes (25%, p < 0.001), monocytes (61%, p < 0.001), endothelial cells (69%, p < 0.001), activated endothelial cells (55%, p < 0.001), and syncytiotrophoblast cells (44%, p < 0.001). Discussion: These results indicate that pravastatin reduces the levels of activated cell-derived membrane vesicles from the maternal vasculature, blood, and placental syncytiotrophoblast of women at high risk of term preeclampsia, suggesting that this statin may be beneficial in reducing endothelial dysfunction and pro-inflammatory and pro-coagulatory state characteristics of the disease.

The impact of early versus delayed cord clamping on hematological and cardiovascular changes in preterm newborns between 24 and 34 weeks' gestation: a randomized clinical trial.

PURPOSE: This study aimed to   investigate hematological and cardiac changes after early (ECC) versus delayed cord clamping (DCC) in preterm infants at 24-34 weeks of gestation. METHODS: Ninety-six healthy pregnant women were assigned randomly to the ECC (< 10 s postpartum, n = 49) or DCC (45-60 s postpartum, n = 47). Primary endpoint was evaluation of neonatal hemoglobin, hematocrit and bilirrubin levels within the first 7 days after birth. A postpartum blood test was performed in the mother and a neonatal echocardiography in the first week of life. RESULTS: We found differences in hematological parameters during the first week of life. On admission, the DCC group had higher hemoglobin levels than the ECC group (18.7 ± 3.0 vs. 16.8 ± 2.4, p < 0.0014) and higher hematocrit values (53.9 ± 8.0 vs. 48.8 ± 6.4, p < 0.0011). Around day 7 of life, hemoglobin levels were also higher in the DCC group compared with the ECC group (16.4 ± 3.8 vs 13.9 ± 2.5, p < 0.005), as was the hematocrit (49.3 ± 12.7 vs 41.2 ± 8.4, p < 0.0087). The need of transfusion was lower in the DCC compared to the ECC (8.5% vs 24.5%; OR: 0.29, 95% CI: 0.09-0.97, p < 0.036). The need for phototherapy was also higher in the DCC (80.9% vs 63.3%; OR: 0.23, 95% CI: 0.06-0.84, p < 0.026). No differences in cardiac parameters or maternal blood tests. CONCLUSION: DCC improved neonatal hematological parameters. No changes in cardiac function were found and maternal blood loss did not increase to require transfusion.

Understanding the Degradation of Methylenediammonium and Its Role in Phase-Stabilizing Formamidinium Lead Triiodide.

Formamidinium lead triiodide (FAPbI3) is the leading candidate for single-junction metal-halide perovskite photovoltaics, despite the metastability of this phase. To enhance its ambient-phase stability and produce world-record photovoltaic efficiencies, methylenediammonium dichloride (MDACl2) has been used as an additive in FAPbI3. MDA2+ has been reported as incorporated into the perovskite lattice alongside Cl-. However, the precise function and role of MDA2+ remain uncertain. Here, we grow FAPbI3 single crystals from a solution containing MDACl2 (FAPbI3-M). We demonstrate that FAPbI3-M crystals are stable against transformation to the photoinactive δ-phase for more than one year under ambient conditions. Critically, we reveal that MDA2+ is not the direct cause of the enhanced material stability. Instead, MDA2+ degrades rapidly to produce ammonium and methaniminium, which subsequently oligomerizes to yield hexamethylenetetramine (HMTA). FAPbI3 crystals grown from a solution containing HMTA (FAPbI3-H) replicate the enhanced α-phase stability of FAPbI3-M. However, we further determine that HMTA is unstable in the perovskite precursor solution, where reaction with FA+ is possible, leading instead to the formation of tetrahydrotriazinium (THTZ-H+). By a combination of liquid- and solid-state NMR techniques, we show that THTZ-H+ is selectively incorporated into the bulk of both FAPbI3-M and FAPbI3-H at ∼0.5 mol % and infer that this addition is responsible for the improved α-phase stability.

Homomorphic Asymmetric Encryption Applied to the Analysis of IoT Communications.

In this paper, we describe the use of homomorphic encryption techniques in order to not only ensure the data are transmitted in a confidential way, but also to use the encrypted data to provide the manager with statistics that allow them to detect the incorrect functioning of a sensor node or a group of sensors due to either malicious data injection, data transmission, or simply sensor damage (miscalibration, faulty sensor functioning). Obtaining these statistical values does not need decryption, so the process is sped up and can be developed in real time. Operating the data in this way ensures privacy and removes the need to maintain a shared key infrastructure between the sensor nodes and the manager nodes that are part of the blockchain infrastructure. In this work, we focus on operations with the sensor nodes that provide data that will be, later, treated as part of the business logic in the agribusiness sector (for example), hence the importance of having fast checking mechanisms in terms of data quality. The results obtained on conventional configurations of sensor nodes encourage the use of this technique in the aforementioned infrastructure.

Factors Involved in Endothelial Dysfunction Related to Angiogenic Disbalance and Oxidative Stress, in Women at High Risk of Term Pre-Eclampsia.

Oxidative and inflammatory stress, angiogenic imbalance, and endothelial dysfunction are pathophysiological mechanisms occurring in pre-eclampsia (PE) that may persist over time and predispose women to a higher risk of cardiovascular disease (CVD) in the future. However, there is little evidence on the vascular function of women at risk of PE who have not developed the disease. The main objective of this research is to study factors and biomarkers involved in endothelial dysfunction related to oxidative stress, angiogenic disbalance, and inflammation in women at high risk of term PE who do not develop the disease. An observational, analytical, retrospective, and descriptive study was carried out in a selected sample of 68 high-risk and 57 non-risk of term PE participants in the STATIN study (FFIS/2016/02/ST EUDRACT No: 2016-005206-19). A significant increase in mean arterial pressure (MAP) levels and oxidative stress biomarkers (uric acid, homocysteine, and total serum antioxidant capacity) was found. Biomarkers of inflammation (interleukin-6 and growth differentiation factor 15) and endothelial function (asymmetric dimethylarginine) were significantly elevated in the group at risk of pre-eclampsia. A significative dependence relationship was also established between MAP and interleukin-6 and uric acid. These results suggest that women at high risk of term PE may represent pregnancies with pre-existing maternal risk factors for CVD, manifested by the own cardiovascular overload of pregnancy. A better understanding of maternal cardiovascular function in pregnancy would allow the improved prediction of CVD late in life in women.

Efficient and Stable Perovskite Solar Cells based on Nitrogen-Doped Carbon Nanodots.

The role of graphitic and amorphous nitrogen-doped carbon dots (N-CDs) as additives for perovskite solar cells (PSCs) is investigated. A detailed study of N-CDs: perovskite (PVSK) blends through X-ray diffraction, nuclear magnetic resonance, field emission scanning electron microscopy, UV-vis, and photoluminescence spectroscopy reveals the existence of interactions between N-CDs and PVSK. The amorphous or graphitic nature of these carbon nanoforms, as well as the interactions between CDs and PVSK, clearly determines the photovoltaic outcome of the PSCs. Thus, a small amount of graphitic carbon dots (g-N-CDs) leads to more-stable PSCs, while maintaining and even improving the power conversion efficiency (PCE). In addition, the long-term evaluation of the g-N-CDs-containing cells shows improvement of the PCE over time, up to 109% of the initial efficiency after 40 days while the reference performance is dropped to 86%.

Triarylamine Enriched Organostannoxane Drums: Synthesis, Optoelectrochemical Properties, Association Studies, and Gelation Behavior.

The straightforward synthesis of three organotin clusters endowed with six triarylamine-based moieties is reported herein. The optoelectronic properties of the molecules, as well as their ability to form gels, were investigated. The association ability of the compounds was studied as well by means of variable temperature nuclear magnetic resonance (NMR) and ultraviolet-visible (UV-vis) spectroscopy. The optimization of the geometry of the compounds has been performed and compared to the X-ray diffraction of the crystals. The results obtained through this comparison are useful for the explanation of their different gelation behaviors. In fact, organostannoxane drum 1 exhibits a strong ability to form organized supramolecular structures by means of a number of noncovalent short contacts that finally yield luminescent organogels in aromatic solvents.

Dendritic-Like Molecules Built on a Pillar[5]arene Core as Hole Transporting Materials for Perovskite Solar Cells.

Invited for the cover of this issue are the groups of S. Seki (Kyoto), G. Reginato (Sesto Fiorentino), J.-F. Nierengarten (Strasbourg), A. Abate (Berlin) and J. L. Delgado (San Sebastian). The image depicts an artistic view of a dendrimer-like hole transporting material at work in a perovskite solar cell. Read the full text of the article at 10.1002/chem.202101110.

Dendritic-Like Molecules Built on a Pillar[5]arene Core as Hole Transporting Materials for Perovskite Solar Cells.

Multi-branched molecules have recently demonstrated interesting behaviour as charge-transporting materials within the fields of perovskite solar cells (PSCs). For this reason, extended triarylamine dendrons have been grafted onto a pillar[5]arene core to generate dendrimer-like compounds, which have been used as hole-transporting materials (HTMs) for PSCs. The performances of the solar cells containing these novel compounds have been extensively investigated. Interestingly, a positive dendritic effect has been evidenced as the hole transporting properties are improved when going from the first to the second-generation compound. The stability of the devices based on the best performing pillar[5]arene material has been also evaluated in a high-throughput ageing setup for 500 h at high temperature. When compared to reference devices prepared from spiro-OMeTAD, the behaviour is similar. An analysis of the economic advantages arising from the use of the pillar[5]arene-based material revealed however that our pillar[5]arene-based material is cheaper than the reference.

Maternal and Perinatal Outcomes Associated With Extremely High Values for the sFlt-1 (Soluble fms-Like Tyrosine Kinase 1)/PlGF (Placental Growth Factor) Ratio.

Background There is little knowledge about the significance of extremely high values (>655) for the ratio of sFlt-1 (soluble fms-like tyrosine kinase 1) to PlGF (placental growth factor). We aim to describe the time-to-delivery interval and maternal and perinatal outcomes when such values are demonstrated while assessing suspected or confirmed placental dysfunction based on clinical or sonographic criteria. Methods and Results A multicenter retrospective cohort study was performed on 237 singleton gestations between 20+0 and 37+0 weeks included at the time of first demonstrating a sFlt-1/PlGF ratio >655. Clinicians were aware of this result, but standard protocols were followed for delivery indication. Main outcomes were compared for women with and without preeclampsia at inclusion. In those with preeclampsia (n=185, of whom 77.3% had fetal growth restriction), severe preeclampsia features and fetal growth restriction in stages III or IV were present in 49.2% and 13.5% cases, respectively, at inclusion and in 77.3% and 28.6% cases, respectively, at delivery. In the group without preeclampsia (n=52, 82.7% had fetal growth restriction), these figures were 0% and 30.8%, respectively, at inclusion and 21.2% and 50%, respectively, at delivery. Interestingly, 28% of women without initial preeclampsia developed it later. The median time to delivery was 4 days (interquartile range: 1-6 days) and 7 days (interquartile range: 3-12 days), respectively (P<0.01). Overall, perinatal mortality was 62.1% before 24 weeks; severe morbidity surpassed 50% before 29 weeks but became absent from 34 weeks. Maternal serious morbidity was high at any gestational age. Conclusions An sFlt-1/PlGF ratio >655 is almost invariably associated with preeclampsia or fetal growth restriction that progresses rapidly. In our tertiary care settings, we observed that maternal adverse outcomes were high throughout gestation, whereas perinatal adverse outcomes diminished as pregnancy advanced.

Is it possible to predict late antepartum stillbirth by means of cerebroplacental ratio and maternal characteristics?

Objective: To examine the potential value of fetal ultrasound and maternal characteristics in the prediction of antepartum stillbirth after 32 weeks' gestation.Methods: This was a retrospective multicenter study in Spain. In 29 pregnancies, umbilical artery pulsatility index (UA PI), middle cerebral artery pulsatility index (MCA PI), cerebroplacental ratio (CPR), estimated fetal weight (EFW), and maternal characteristics were recorded within 15 days prior to a stillbirth. The values of UA PI, MCA PI, and CPR were converted into multiples of the normal median (MoM) for gestational age and the EFW was expressed as percentile according to a Spanish reference range for gestational age. Data from the 29 pregnancies with stillbirths and 2298 control pregnancies resulting in livebirths were compared and multivariate logistic regression analysis was used to determine significant predictors of stillbirth.Results: The only significant predictor of stillbirth was CPR (OR = 0.161, 95% confidence interval [CI] 0.035, 0.654; p = .014); the area under the receiver operating characteristics curve was 0.663 (95% CI 0.545, 0.782) and the detection rate (DR) was 32.14% at a 10% false-positive rate (FPR). In addition, when we included MCA and UA PI MoM instead of CPR, only MCA PI MoM was significant (OR = 0.104, 95% confidence interval [CI] 0.013, 0.735; p = .029), with similar prediction abilities (area under the curve (AUC) 0.645, DR 28.6%, FPR 10%).Conclusions: The CPR and MCA PI are predictors of late stillbirth but the performance of prediction is poor.

Acceptability, tolerability, and effects on symptoms and signs of vulvovaginitis of a non-soap, herbal-based intimate hygiene solution (Zelesse®).

OBJECTIVE: To evaluate the acceptability, tolerability, and effects on vulvovaginitis symptoms and signs of a non-soap, herbal-based intimate solution (Zelesse®). METHODS: We conducted a prospective, observational, multicenter study including adult women with symptoms and signs of vulvovaginitis with various etiologies, including candidiasis, trichomoniasis, bacterial vaginosis, and atrophic and irritative vaginitis. The presence and intensity of signs (edema, erythema, vaginal discharge) and symptoms (pruritus) of vulvovaginitis were evaluated before and after 5-15 days of daily use of Zelesse® alone or as a coadjuvant in antimicrobial therapy. Variables following a normal distribution and categorical variables were analyzed using the Student t-test and chi-square or Fisher's exact test, respectively. RESULTS: A total 137 women were enrolled in the study; 87 (63.5%) women received concomitant antimicrobials and 50 (36.5%) used Zelesse® only. Global symptom scores and frequency of patients with vulvovaginitis signs and symptoms, and their mean intensity, decreased after treatment in both patient groups. Vaginal pH and (in the Zelesse®-only group) vaginal flora remained unaltered. The product was safe, well tolerated, and highly accepted by patients. CONCLUSIONS: Zelesse®, the non-soap herbal-based solution in this study, may represent a safe and effective option for symptomatic relief of vulvovaginitis.

Perovskite Solar Cells Based on Oligotriarylamine Hexaarylbenzene as Hole-Transporting Materials.

A cobalt-catalyzed cyclotrimerization of bis(aryl)alkyne is used as an innovative tool to obtain hole-transport materials (HTMs). The novel HTM containing six units of oligotriarylamine (HAB1), characterized by UV-vis, cyclic voltammetry, DFT, and thermogravimetric analysis, confirms its suitability as an efficient HTM in PSCs. A PCE of 17.5% was obtained in HAB1-containing PSCs, a performance comparable to that obtained with spiro-OMeTAD and with slightly better thermal stability.

Physicochemical Phenomena and Application in Solar Cells of Perovskite:Fullerene Films.

Beyond the use of fullerenes as electron-transporting layers in perovskite solar cells, their introduction into a perovskite active layer has been ascertained as a very promising strategy for device improvement. In this sense, this Perspective summarizes the studies in which perovskite:fullerene systems were employed, covering the different methodologies for introducing fullerenes inside the perovskite layer. In particular, fill factor was the most benefited parameter, which was ascribed to minimized pinhole density and fullerene passivating role. We discussed the importance of their ability to passivate trap states and, in this regard, focused on the affinity of fullerenes toward these sites. Additionally, the different nature of the fullerene and its environment in the active layer were found to determine the proper distribution of fullerene so that they could passivate the defects along grain boundaries. Understanding this mechanism would provide further insights for new methodologies and fullerene derivatives with enhanced trap-passivating ability.

Fullerene-Based Materials as Hole-Transporting/Electron-Blocking Layers: Applications in Perovskite Solar Cells.

Here we report for the first time an efficient fullerene-based compound, FU7, able to act as hole-transporting material (HTM) and electron blocking contact. It has been applied on perovskite solar cells (PSCs), obtaining 0.81 times the efficiency of PSCs with the standard HTM, spiro-OMeTAD, with the additional advantage that this performance is reached without any additive introduced in the HTM layer. Moreover, as a proof of concept, we have described for the first time efficient PSCs in which both selective contacts are fullerene derivatives, to obtain unprecedented "fullerene sandwich" PSCs.

External iliac artery Doppler assessment in the prediction of adverse pregnancy outcomes.

PURPOSE: The purpose of this study is to investigate the potential role of the mean external iliac artery pulsatility index (EIA-PI) as a predictor of adverse obstetric outcomes such as preeclampsia, gestational hypertension and small for gestational age (SGA). METHODS: In women attending for first trimester screening at 11 + 0-13 + 6 weeks of gestation, we recorded maternal characteristics and measured EIA mean PI and uterine artery mean PI. We compared EIA mean PI in those that developed preeclampsia (n = 84), gestational hypertension (n = 50) or small for gestational age (n = 444) with those unaffected (n = 3736). Regression analysis was used to first determine which of the factors among the maternal variables were significant predictors of EIA mean PI in the unaffected group and, second, to predict adverse pregnancy outcomes. RESULTS: In the unaffected group, EIA mean PI increased with maternal age and decreased with mean blood pressure. Additionally, EIA mean PI was lower in cigarette smokers. Compared with the unaffected group, EIA mean PI was significantly lower in women who develop gestational hypertension or SGA below third centile. CONCLUSION: EIA mean PI in the first trimester is decreased in women who develop gestational hypertension and in those complicated by SGA below third centile. More studies are needed to confirm these findings.