Close-Space Sublimation as a Scalable Method for Perovskite Solar Cells.

Vacuum techniques for perovskite photovoltaics (PV) are promising for their scalability but are rarely studied with techniques readily adaptable for industry. In this work, we study the use of close-space sublimation (CSS) for making perovskite solar cells, a technique that has seen widespread use in industry, including in PV, and benefits from high material-transfer and low working pressures. A pressed pellet of formamidinium iodide (FAI) can be used multiple times as an organic source, without needing replacement. Using CSS at a rough vacuum (10 mbar), efficient cesium formamidinium lead iodide perovskite based solar cells are obtained reaching a maximum photoconversion efficiency (PCE) of 18.7%. They maintain their performance for >650 h when thermally stressed at 85 °C in a nitrogen environment. To explain the initial rise in PCE upon heating, we used drift-diffusion simulations and identified a reduction in bulk trap density as the primary factor.

Interval cancer in the Córdoba Breast Tomosynthesis Screening Trial (CBTST): comparison of digital breast tomosynthesis plus digital mammography to digital mammography alone.

PURPOSE: This work aims to compare the interval cancer rate and interval cancer characteristics between women screened with digital breast tomosynthesis (DBT) + digital mammography (DM) and those screened with DM alone. METHODS: The interval cancer rate and interval cancer characteristics of the study population included in the Córdoba Breast Tomosynthesis Screening Trial (CBTST) were compared to a contemporary control population screened with DM. The tumour characteristics of screen-detected and interval cancers were also compared. Contingency tables were used to compare interval cancer rates. The chi-square test and Fisher's exact test were used to compare the qualitative characteristics of the cancers whereas Student's t test and the Mann-Whitney U test were used to analyse quantitative features. RESULTS: A total of 16,068 screening exams with DBT + DM were conducted within the CBTST (mean age 57.59 ± 5.9 [SD]) between January 2015 and December 2016 (study population). In parallel, 23,787 women (mean age 58.89 ± 5.9 standard deviation [SD]) were screened with DM (control population). The interval cancer rate was lower in the study population than in the control population (15 [0.93‰; 95% confidence interval (CI): 0.73, 1.14] vs 43 [1.8‰; 95% CI: 1.58, 2.04] respectively; p = 0.045). The difference in rate was more marked in women with dense breasts (0.95‰ in the study population vs 3.17‰ in the control population; p = 0.031). Interval cancers were smaller in the study population than in the control population (p = 0.031). CONCLUSIONS: The interval cancer rate was lower in women screened with DBT + DM compared to those screened with DM alone. These differences were more pronounced in women with dense breasts. CLINICAL RELEVANCE STATEMENT: Women screened using tomosynthesis and digital mammography had a lower rate of interval cancer than women screened with digital mammography, with the greatest difference in the interval cancer rate observed in women with dense breasts. KEY POINTS: • The interval cancer rate was lower in the study population (digital breast tomosynthesis [DBT] + digital mammography [DM]) than in the control population (DM). • The difference in interval cancer rates was more pronounced in women with dense breasts. • Interval cancers were smaller in the study population (DBT + DM) than in the control population (DM).

Fast Coevaporation of 1 µm Thick Perovskite Solar Cells.

Coevaporation of perovskite films allows for a fine control over the material stoichiometry and thickness but is typically slow, leading to several-hour processes to obtain thick films required for photovoltaic applications. In this work, we demonstrate the coevaporation of perovskite layers using faster deposition rates, obtaining 1 µm thick films in approximately 50 min. We observed distinct structural properties and obtained devices with efficiency exceeding 19%, demonstrating the relevance of this deposition process from a material perspective and also in view of potential industrialization.

Association between enhanced recovery after surgery protocol compliance and clinical complications: a cohort study

Abstract Background Enhanced Recovery After Surgery (ERAS) protocol is composed by evidence-based interventions that aim to improve recovery through a reduction in surgical stress response. Although ERAS protocols have been introduced across the globe, exhaustive implementation is not as common. We aimed to study the ERAS protocol compliance in colorectal surgery, assessing the relationship between compliance and postoperative complications. Methods A single-center cohort study was conducted. All consecutive patients admitted to elective colorectal surgery were included. We assessed study endpoints according to ERAS protocol perioperative compliance score above 75%. Our primary endpoint was a composite of postoperative events, which includes in-hospital postoperative complications and need for reoperation after 30 days and need for readmission after discharge. Secondary endpoints were surgery-to-discharge time, postoperative use of only non-opioid adjuvants and the individual components of the primary endpoint. Results A total of 224 colorectal patients were included. The primary endpoint occurred in 59.2% (n = 58) of non-compliant patients comparing to 34.1% (n = 43) in compliant patients. In univariate analysis, compliance to ERAS protocol had an inferior risk for the primary endpoint (p< 0.001). In a logistic regression model, compliance was independently associated with a reduced risk for the primary endpoint with a odds-ratio of 0.42 (95% CI 0.23-0.75, p= 0.004). Conclusion Compliance with the ERAS protocol is associated with less complications, a reduced surgery-to-discharge time and use of only non-opioid adjuvants in the postoperative period. More studies are needed to target the most appropriate compliance goal.

Early versus late sphenopalatine ganglion block with ropivacaine in postdural puncture headache: an observational study

Abstract Background Postdural puncture headache (PDPH) is a common complication of neuraxial techniques which delays patients' discharge. Sphenopalatine ganglion block (SPGB) is a safe bedside technique with comparable efficacy to Epidural Blood Patch, the gold-standard treatment. There is no evidence on the ideal timing for SPGB performance. We aimed to evaluate the difference between early versus late SPGB concerning efficacy, symptom recurrence and hospital length of stay. Methods We present an observational study with 41 patients diagnosed with PDPH who were submitted to SPGB with ropivacaine 0,75%. The study sample (n = 41) was divided in two groups: an early (less than 24 hours after diagnosis) and a late (more than 24 hours after diagnosis) SPGB group. Pain was evaluated 15 minutes after the block and follow up occurred daily until patients were discharged. Patients' demographic characteristics, neuraxial technique, timing of SPGB, qualitative pain relief and post-SPGB length of stay were registered and analyzed with SPSS statistics (v26) software. Results Early SPGB resulted in a significant reduction in length of stay (p = 0,009) and symptom recurrence (p = 0,036), showing equally effective pain relief, compared to late SPGB. Conclusions SPGB was equally effective in both groups. Data showed that early SPGB reduces length of hospital stay and symptom recurrence, which potentially allows early resumption of daily activities and a reduction in total health costs.

Association between enhanced recovery after surgery protocol compliance and clinical complications: a cohort study.

BACKGROUND: Enhanced Recovery After Surgery (ERAS) protocol is composed by evidence-based interventions that aim to improve recovery through a reduction in surgical stress response. Although ERAS protocols have been introduced across the globe, exhaustive implementation is not as common. We aimed to study the ERAS protocol compliance in colorectal surgery, assessing the relationship between compliance and postoperative complications. METHODS: A single-center cohort study was conducted. All consecutive patients admitted to elective colorectal surgery were included. We assessed study endpoints according to ERAS protocol perioperative compliance score above 75%. Our primary endpoint was a composite of postoperative events, which includes in-hospital postoperative complications and need for reoperation after 30 days and need for readmission after discharge. Secondary endpoints were surgery-to-discharge time, postoperative use of only non-opioid adjuvants and the individual components of the primary endpoint. RESULTS: A total of 224 colorectal patients were included. The primary endpoint occurred in 59.2% (n.á=.á58) of non-compliant patients comparing to 34.1% (n.á=.á43) in compliant patients. In univariate analysis, compliance to ERAS protocol had an inferior risk for the primary endpoint (p.á<.á0.001). In a logistic regression model, compliance was independently associated with a reduced risk for the primary endpoint with a odds-ratio of 0.42 (95% CI 0.23.Çô0.75, p.á=.á0.004). CONCLUSION: Compliance with the ERAS protocol is associated with less complications, a reduced surgery-to-discharge time and use of only non-opioid adjuvants in the postoperative period. More studies are needed to target the most appropriate compliance goal.

Early versus late sphenopalatine ganglion block with ropivacaine in postdural puncture headache: an observational study.

BACKGROUND: Postdural puncture headache (PDPH) is a common complication of neuraxial techniques which delays patients.ÇÖ discharge. Sphenopalatine ganglion block (SPGB) is a safe bedside technique with comparable efficacy to Epidural Blood Patch, the gold-standard treatment. There is no evidence on the ideal timing for SPGB performance. We aimed to evaluate the difference between early versus late SPGB concerning efficacy, symptom recurrence and hospital length of stay. METHODS: We present an observational study with 41 patients diagnosed with PDPH who were submitted to SPGB with ropivacaine 0,75%. The study sample (n=41) was divided in two groups: an early (less than 24hours after diagnosis) and a late (more than 24hours after diagnosis) SPGB group. Pain was evaluated 15minutes after the block and follow up occurred daily until patients were discharged. PATIENTS: ÇÖ demographic characteristics, neuraxial technique, timing of SPGB, qualitative pain relief and post-SPGB length of stay were registered and analyzed with SPSS statistics (v26) software. RESULTS: Early SPGB resulted in a significant reduction in length of stay (p=0,009) and symptom recurrence (p=0,036), showing equally effective pain relief, compared to late SPGB. CONCLUSIONS: SPGB was equally effective in both groups. Data showed that early SPGB reduces length of hospital stay and symptom recurrence, which potentially allows early resumption of daily activities and a reduction in total health costs.

Pure Iodide Multication Wide Bandgap Perovskites by Vacuum Deposition.

The CsPbI3 perovskite has a suitable bandgap (≈1.7 eV) for application in tandem solar cells. One challenge for this compound is that the semiconducting perovskite phase is not stable at room temperature, when it tends to form a yellow nonperovskite phase with a bandgap of approximately 2.8 eV. Therefore, many reports have been focused on the stabilization of the CsPbI3 black perovskite phase through the use of additives during solution processing. Vacuum deposited CsPbI3 has been seldom reported, as in this case, the insertion of stabilizing agents is more challenging. In this work, we demonstrate the vacuum processing of CsPbI3 perovskite films at room temperature, obtained by incorporating dimethylammonium iodide by cosublimation with CsI and PbI2. As-prepared films were applied in planar solar cells, leading to an average power conversion efficiency (PCE) exceeding 12%. In order to improve the device performance, we introduced a third A-site cation (methylammonium) in a four-source deposition process. This pure iodide formulation can be used in wide bandgap solar cells with a PCE up to 14.8%.

Perovskite/Perovskite Tandem Solar Cells in the Substrate Configuration with Potential for Bifacial Operation.

Perovskite/perovskite tandem solar cells have recently exceeded the record power conversion efficiency (PCE) of single-junction perovskite solar cells. They are typically built in the superstrate configuration, in which the device is illuminated from the substrate side. This limits the fabrication of the solar cell to transparent substrates, typically glass coated with a transparent conductive oxide (TCO), and adds constraints because the first subcell that is deposited on the substrate must contain the wide-bandgap perovskite. However, devices in the substrate configuration could potentially be fabricated on a large variety of opaque and inexpensive substrates, such as plastic and metal foils. Importantly, in the substrate configuration the narrow-bandgap subcell is deposited first, which allows for more freedom in the device design. In this work, we report perovskite/perovskite tandem solar cells fabricated in the substrate configuration. As the substrate we use TCO-coated glass on which a solution-processed narrow-bandgap perovskite solar cell is deposited. All of the other layers are then processed using vacuum sublimation, starting with the charge recombination layers, then the wide-bandgap perovskite subcell, and finishing with the transparent top TCO electrode. Proof-of-concept tandem solar cells show a maximum PCE of 20%, which is still moderate compared to those of best-in-class devices realized in the superstrate configuration yet higher than those of the corresponding single-junction devices in the substrate configuration. As both the top and bottom electrodes are semitransparent, these devices also have the potential to be used as bifacial tandem solar cells.

Mechanistic Insights into the Role of the Bis(trifluoromethanesulfonyl)imide Ion in Coevaporated p-i-n Perovskite Solar Cells.

Hybrid lead halide perovskites have reached comparable efficiencies to state-of-the-art silicon solar cell technologies. However, a remaining key challenge toward commercialization is the resolution of the perovskite device instability. In this work, we identify for the first time the mobile nature of bis(trifluoromethanesulfonyl)imide (TFSI-), a typical anion extensively employed in p-type dopants for 2,2'7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'spirofluorene (spiro-OMeTAD). We demonstrate that TFSI- can migrate through the perovskite layer via the grain boundaries and accumulate at the perovskite/electron-transporting layer (ETL) interface. Our findings reveal that the migration of TFSI- enhances the device performance and stability, resulting in highly stable p-i-n cells that retain 90% of their initial performance after 1600 h of continuous testing. Our systematic study, which targeted the effect of the nature of the dopant and its concentration, also shows that TFSI- acts as a dynamic defect-healing agent, which self-passivates the perovskite crystal defects during the migration process and thereby decreases nonradiative recombination pathways.

Molecular Design and Operational Stability: Toward Stable 3D/2D Perovskite Interlayers.

Despite organic/inorganic lead halide perovskite solar cells becoming one of the most promising next-generation photovoltaic materials, instability under heat and light soaking remains unsolved. In this work, a highly hydrophobic cation, perfluorobenzylammonium iodide (5FBzAI), is designed and a 2D perovskite with reinforced intermolecular interactions is engineered, providing improved passivation at the interface that reduces charge recombination and enhances cell stability compared with benchmark 2D systems. Motivated by the strong halogen bond interaction, (5FBzAI)2PbI4 used as a capping layer aligns in in-plane crystal orientation, inducing a reproducible increase of ≈60 mV in the V oc, a twofold improvement compared with its analogous monofluorinated phenylethylammonium iodide (PEAI) recently reported. This endows the system with high power conversion efficiency of 21.65% and extended operational stability after 1100 h of continuous illumination, outlining directions for future work.

An Efficient Approach to Fabricate Air-Stable Perovskite Solar Cells via Addition of a Self-Polymerizing Ionic Liquid.

Despite the excellent photovoltaic properties achieved by perovskite solar cells at the laboratory scale, hybrid perovskites decompose in the presence of air, especially at high temperatures and in humid environments. Consequently, high-efficiency perovskites are usually prepared in dry/inert environments, which are expensive and less convenient for scale-up purposes. Here, a new approach based on the inclusion of an in situ polymerizable ionic liquid, 1,3-bis(4-vinylbenzyl)imidazolium chloride ([bvbim]Cl), is presented, which allows perovskite films to be manufactured under humid environments, additionally leading to a material with improved quality and long-term stability. The approach, which is transferrable to several perovskite formulations, allows efficiencies as high as 17% for MAPbI3 processed in air % relative humidity (RH) ≥30 (from an initial 15%), and 19.92% for FAMAPbI3 fabricated in %RH ≥50 (from an initial 17%), providing one of the best performances to date under similar conditions.

Co-evaporation as an optimal technique towards compact methylammonium bismuth iodide layers.

The most studied perovskite-based solar cells reported up to date contain the toxic lead in its composition. Photovoltaic research and development towards non-toxic, lead-free perovskite solar cells are critical to finding alternatives to reduce human health concerns associated with them. Bismuth-based perovskite variants, especially in the form of methylammonium bismuth iodide (MBI), is a good candidate for the non-toxic light absorber. However, the reported perovskite variant MBI thin films prepared by the solution process so far suffers from poor morphology and surface coverage. In this work, we investigate for the first time the optoelectronic, crystallographic and morphological properties of MBI thin films prepared via thermal co-evaporation of MAI and BiI3. We find by modifying the precursor ratio that the layer with pure MBI composition lead to uniform, compact and homogeneous layers, broadening the options of deposition techniques for lead-free based perovskite solar cells.

Azatruxene-Based, Dumbbell-Shaped, Donor-π-Bridge-Donor Hole-Transporting Materials for Perovskite Solar Cells.

Three novel donor-π-bridge-donor (D-π-D) hole-transporting materials (HTMs) featuring triazatruxene electron-donating units bridged by different 3,4-ethylenedioxythiophene (EDOT) π-conjugated linkers have been synthesized, characterized, and implemented in mesoporous perovskite solar cells (PSCs). The optoelectronic properties of the new dumbbell-shaped derivatives (DTTXs) are highly influenced by the chemical structure of the EDOT-based linker. Red-shifted absorption and emission and a stronger donor ability were observed in passing from DTTX-1 to DTTX-2 due to the extended π-conjugation. DTTX-3 featured an intramolecular charge transfer between the external triazatruxene units and the azomethine-EDOT central scaffold, resulting in a more pronounced redshift. The three new derivatives have been tested in combination with the state-of-the-art triple-cation perovskite [(FAPbI3 )0.87 (MAPbBr3 )0.13 ]0.92 [CsPbI3 ]0.08 in standard mesoporous PSCs. Remarkable power conversion efficiencies of 17.48 % and 18.30 % were measured for DTTX-1 and DTTX-2, respectively, close to that measured for the benchmarking HTM spiro-OMeTAD (18.92 %), under 100 mA cm-2 AM 1.5G solar illumination. PSCs with DTTX-3 reached a PCE value of 12.68 %, which is attributed to the poorer film formation in comparison to DTTX-1 and DTTX-2. These PCE values are in perfect agreement with the conductivity and hole mobility values determined for the new compounds and spiro-OMeTAD. Steady-state photoluminescence further confirmed the potential of DTTX-1 and DTTX-2 for hole-transport applications as an alternative to spiro-OMeTAD.

Benzothiadiazole Aryl-amine Based Materials as Efficient Hole Carriers in Perovskite Solar Cells.

Four hole transport materials (HTMs) based on a benzothiadiazole (BT) central core have been synthesized and successfully employed in triple-cation mixed-halide perovskite solar cells (PSCs), reaching 18.05% solar to energy conversion efficiency. The synthesis of these HTMs follows the push-and-pull approach to modulate the HOMO energy level by combining the BT group as an electron acceptor and diphenyl- and triphenyl-amines as electron donors. Here we show that despite adjusting the HOMO energy level to that of the perovskite is a believed requisite to achieve efficient interfacial hole transfer, additional factors must be taken into account to design novel and efficient HTMs, such as a high hole mobility, solubility in organic solvents, and thermal stability.

Minimization of Carrier Losses for Efficient Perovskite Solar Cells through Structural Modification of Triphenylamine Derivatives.

Three hole transport materials (HTMs) based on a substituted triphenylamine moiety have been synthesized and successfully employed in triple-cation mixed-halide PSCs, reaching efficiencies of 19.4 %. The efficiencies, comparable to those obtained using spiro-OMeTAD, point them out as promising candidates for easily attainable and cost-effective alternatives for PSCs, given their facile synthesis from commercially available materials. Interestingly, although all these HTMs show similar chemical and physical properties, they provide different carrier recombination kinetics. Our results demonstrate that is feasible through the molecular design of the HTM to minimize carrier losses and, thus, increase the solar cell efficiencies.

Doped but Stable: Spirobisacridine Hole Transporting Materials for Hysteresis-Free and Stable Perovskite Solar Cells.

Four spirobisacridine (SBA) hole-transporting materials were synthesized and employed in perovskite solar cells (PSCs). The molecules bear electronically inert alkyl chains of different length and bulkiness, attached to in-plane N atoms of nearly orthogonal spiro-connected acridines. Di-p-methoxyphenylamine (DMPA) substituents tailored to the central SBA-platform define electronic properties of the materials mimicking the structure of the benchmark 2,2',7,7'-tetrakis(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene (spiro-MeOTAD), while the alkyl pending groups affect molecular packing in thin films and affect the long-term performance of PSCs. Devices with SBA-based hole transporting layers (HTL) attain efficiencies on par with spiro-MeOTAD. More importantly, solar cells with the new HTMs are hysteresis-free and demonstrate good operational stability, despite being doped as spiro-MeOTAD. The best performing MeSBA-DMPA retained 88% of the initial efficiency after a 1000 h aging test under constant illumination. The results clearly demonstrate that SBA-based compounds are potent candidates for a design of new HTMs for PSCs with improved longevity.

CLINICAL CHARACTERISTICS OF PRIMARY EXTRANODAL VERSUS NODAL DIFFUSE LARGE B-CELL LYMPHOMA: A RETROSPECTIVE COHORT STUDY IN A CANCER CENTER.

BACKGROUND: The outcome of patients with primary extranodal diffuse large B-cell lymphoma (PE-DLBCL) varies according to the primary site involved. Primary gastrointestinal, breast, bone, craniofacial, and testicular DLBCL are rare extranodal manifestations of DLBCL. OBJECTIVE: The objective of the study was to describe the clinical course of patients with PE-DLBCL disease in a referral cancer center. RESULTS: From 637 patients, 51 (8.77%) were considered as having PE-DLBCL (25 gastrointestinal, 12 craniofacial, 6 breast, 5 bone, and 3 with primary testicular DLBCL). Complete remission was higher in all PE-DLBCL sites (100% in testicular, 92.6% craniofacial, 83.3% breast, 80% bone, and 80% gastrointestinal) compared with 73.3% in nodal DLBCL. Although 2 cases with breast PE-DLBC relapsed, they achieved a complete response with chemotherapy. The overall survival at 5 years was 100%, 80%, 78%, 58%, 58%, and 62% for patients with primary breast, primary bone, gastrointestinal, primary craniofacial, primary testicular, and nodal DLBCL, respectively. CONCLUSIONS: PE-DLBCLs constitute rare, primary sites of lymphoproliferative disorders in most cases, with localized disease and good prognosis. They require a combined chemoimmunotherapy with radiotherapy in most cases to improve local and systemic disease.

Correction: A comparative study of Ir(iii) complexes with pyrazino[2,3-f][1,10]phenanthroline and pyrazino[2,3-f][4,7]phenanthroline ligands in light-emitting electrochemical cells (LECs).

Correction for 'A comparative study of Ir(iii) complexes with pyrazino[2,3-f][1,10]phenanthroline and pyrazino[2,3-f][4,7]phenanthroline ligands in light-emitting electrochemical cells (LECs)' by Iván González et al., Dalton Trans., 2015, 44, 14771-14781.

Clinical characteristics of primary extranodal versus nodal diffuse large B-Cell Lymphoma: A retrospective cohort study in a cancer center

Background The outcome of patients with primary extranodal diffuse large B-cell lymphoma (PE-DLBCL) varies according to the primary site involved. Primary gastrointestinal, breast, bone, craniofacial, and testicular DLBCL are rare extranodal manifestations of DLBCL. Objective The objective of the study was to describe the clinical course of patients with PE-DLBCL disease in a referral cancer center. Results From 637 patients, 51 (8.77%) were considered as having PE-DLBCL (25 gastrointestinal, 12 craniofacial, 6 breast, 5 bone, and 3 with primary testicular DLBCL). Complete remission was higher in all PE-DLBCL sites (100% in testicular, 92.6% craniofacial, 83.3% breast, 80% bone, and 80% gastrointestinal) compared with 73.3% in nodal DLBCL. Although 2 cases with breast PE-DLBC relapsed, they achieved a complete response with chemotherapy. The overall survival at 5 years was 100%, 80%, 78%, 58%, 58%, and 62% for patients with primary breast, primary bone, gastrointestinal, primary craniofacial, primary testicular, and nodal DLBCL, respectively. Conclusions PE-DLBCLs constitute rare, primary sites of lymphoproliferative disorders in most cases, with localized disease and good prognosis. They require a combined chemoimmunotherapy with radiotherapy in most cases to improve local and systemic disease.