CONTEXT In patients with suspected lung cancer, the presence of mediastinal lymph node metastasis is a critical determinant of therapy and prognosis.
Invasive staging with pathologic confirmation is ...recommended. Many methods for staging exist; mediastinoscopy, an invasive procedure requiring general anesthesia, is currently regarded as the diagnostic standard. OBJECTIVE To compare the diagnostic accuracy of 3 methods of minimally invasive endoscopic staging (and their combinations): traditional transbronchial needle aspiration (TBNA), endobronchial ultrasound-guided fine-needle aspiration (EBUS-FNA), and transesophageal endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). In particular,
we aimed to compare EBUS-FNA with TBNA. DESIGN, SETTING, AND PARTICIPANTS Invasive staging of the mediastinum among consecutive patients with suspected lung cancer at a US academic medical center from November 2004 through October 2006. INTERVENTION TBNA, EBUS-FNA, and EUS-FNA performed sequentially as a single combined procedure. MAIN OUTCOME MEASURE Sensitivity for detecting mediastinal lymph node metastases,
using pathologic confirmation and 6- to 12-month clinical follow-up as the criterion standard. RESULTS Among 138 patients who met all study criteria, 42 (30%) had malignant lymph nodes. EBUS-FNA was more sensitive than TBNA, detecting 29 (69%) vs 15 (36%) malignant lymph nodes (P = .003). The combination of EUS-FNA and EBUS-FNA (EUS plus EBUS) had higher estimated sensitivity (93% 39/42; 95% confidence interval, 81%-99%) and negative predictive value (97% 96/99; 95%
confidence interval, 91%-99%) compared with either method alone. EUS plus EBUS also had higher sensitivity and higher negative predictive value for detecting lymph nodes in any mediastinal location and for patients without lymph node enlargement on chest computed tomography. CONCLUSIONS These findings suggest that EBUS-FNA has higher sensitivity than TBNA and that EUS plus EBUS may allow near-complete minimally invasive mediastinal staging in patients with suspected lung cancer.
These results require confirmation in other studies but suggest that EUS plus EBUS may be an alternative approach for mediastinal staging in patients with suspected lung cancer.
Aging is associated with sarcopenia. The loss of strength results in decreased muscle mass and motor function. This process accelerates the progressive muscle deterioration observed in older adults, ...favoring the presence of debilitating pathologies. In addition, sarcopenia leads to a decrease in quality of life, significantly affecting self-sufficiency. Altogether, these results in an increase in economic resources from the National Health Systems devoted to mitigating this problem in the elderly, particularly in developed countries. Different etiological determinants are involved in the progression of the disease, including: neurological factors, endocrine alterations, as well as nutritional and lifestyle changes related to the adoption of more sedentary habits. Molecular and cellular mechanisms have not been clearly characterized, resulting in the absence of an effective treatment for sarcopenia. Nevertheless, physical activity seems to be the sole strategy to delay sarcopenia and its symptoms. The present review intends to bring together the data explaining how physical activity modulates at a molecular and cellular level all factors that predispose or favor the progression of this deteriorating pathology.
Tin halide perovskites attract incremental attention to deliver lead‐free perovskite solar cells. Nevertheless, disordered crystal growth and low defect formation energy, related to Sn(II) oxidation ...to Sn(IV), limit the efficiency and stability of solar cells. Engineering the processing from perovskite precursor solution preparation to film crystallization is crucial to tackle these issues and enable the full photovoltaic potential of tin halide perovskites. Herein, the ionic liquid n‐butylammonium acetate (BAAc) is used to tune the tin coordination with specific O…Sn chelating bonds and NH…X hydrogen bonds. The coordination between BAAc and tin enables modulation of the crystallization of the perovskite in a thin film. The resulting BAAc‐containing perovskite films are more compact and have a preferential crystal orientation. Moreover, a lower amount of Sn(IV) and related chemical defects are found for the BAAc‐containing perovskites. Tin halide perovskite solar cells processed with BAAc show a power conversion efficiency of over 10%. This value is retained after storing the devices for over 1000 h in nitrogen. This work paves the way toward a more controlled tin‐based perovskite crystallization for stable and efficient lead‐free perovskite photovoltaics.
The synergistic strategy of tuning the solution coordination and crystallization process by introducing ionic liquid is implemented to successfully fabricate pinhole‐free tin perovskite films with preferential crystal orientation, which possess improved oxidation repellency for Sn(II) and enhanced hydrophobicity. As a result, the stabilization of high‐efficiency lead‐free tin halide perovskite solar cells is achieved.
Severe cases of COVID‐19 infection, often leading to death, have been associated with variants of acute respiratory distress syndrome (ARDS). Cell therapy with mesenchymal stromal cells (MSCs) is a ...potential treatment for COVID‐19 ARDS based on preclinical and clinical studies supporting the concept that MSCs modulate the inflammatory and remodeling processes and restore alveolo‐capillary barriers. The authors performed a systematic literature review and random‐effects meta‐analysis to determine the potential value of MSC therapy for treating COVID‐19‐infected patients with ARDS. Publications in all languages from 1990 to March 31, 2020 were reviewed, yielding 2691 studies, of which nine were included. MSCs were intravenously or intratracheally administered in 117 participants, who were followed for 14 days to 5 years. All MSCs were allogeneic from bone marrow, umbilical cord, menstrual blood, adipose tissue, or unreported sources. Combined mortality showed a favorable trend but did not reach statistical significance. No related serious adverse events were reported and mild adverse events resolved spontaneously. A trend was found of improved radiographic findings, pulmonary function (lung compliance, tidal volumes, PaO2/FiO2 ratio, alveolo‐capillary injury), and inflammatory biomarker levels. No comparisons were made between MSCs of different sources.
In ARDS, pro‐inflammatory cytokines contribute to the disruption of the alveolar – capillary membrane, edema, and pneumocyte damage. MSCs modulate the inflammatory milieu by T‐cell and macrophage redirection, and anti‐inflammatory cytokine production. Clinical trials assessing MSC therapy in ARDS have shown that MSCs have been associated with a favorable trend in morality reduction, pulmonary function improvement, and cytokine correction.
Fluoride Chemistry in Tin Halide Perovskites Pascual, Jorge; Flatken, Marion; Félix, Roberto ...
Angewandte Chemie,
September 20, 2021, Letnik:
60, Številka:
39
Journal Article
Recenzirano
Odprti dostop
Tin is the frontrunner for substituting toxic lead in perovskite solar cells. However, tin suffers the detrimental oxidation of SnII to SnIV. Most of reported strategies employ SnF2 in the perovskite ...precursor solution to prevent SnIV formation. Nevertheless, the working mechanism of this additive remains debated. To further elucidate it, we investigate the fluoride chemistry in tin halide perovskites by complementary analytical tools. NMR analysis of the precursor solution discloses a strong preferential affinity of fluoride anions for SnIV over SnII, selectively complexing it as SnF4. Hard X‐ray photoelectron spectroscopy on films shows the lower tendency of SnF4 than SnI4 to get included in the perovskite structure, hence preventing the inclusion of SnIV in the film. Finally, small‐angle X‐ray scattering reveals the strong influence of fluoride on the colloidal chemistry of precursor dispersions, directly affecting perovskite crystallization.
Fluoride chemistry in tin halide perovskites improves the crystallization process. Fluoride anions selectively coordinate and remove SnIV and affect the colloidal properties in solution. This study describes the working mechanism of SnF2 and highlights the importance of solution chemistry for controlling crystallization and SnII oxidation in tin halide perovskites.
Background/objectives
Histamine has shown a possible role in the etiopathogenesis of migraine. It has been reported an association between some polymorphisms in the diamine oxidase (DAO) gene and ...migraine, especially in women. Two studies addressing DAO activity in migraine patients showed conflicting results. We investigated the possible relationship of serum DAO activity and histamine levels and 3 polymorphisms in the DAO gene with the risk for migraine.
Methods
We studied the frequencies of DAO rs10156191, rs1049742 and rs1049793 genotypes and allelic variants in 298 migraine patients and 360 healthy controls (using a TaqMan‐based qPCR assay), and serum DAO activity and histamine levels in a subset of 99 migraine patients and 115 controls with strict exclusion criteria, and analysed the relationship of these variables with several clinical features of migraine.
Results
The frequencies of the DAO genotypes and allelic variants analysed were similar in migraine patients and controls. Serum DAO activity was significantly higher in migraine patients (Vmax/Km 4.24 ± 2.93 vs. 3.60 ± 7.64, p < 0.001), especially in females (Vmax/Km 4.63 ± 2.96 vs. 3.18 ± 2.32, p < 0.0001), while serum histamine was similar in both study groups.
Conclusion
Serum DAO activity was increased in patients with migraine, especially in females, while serum histamine levels were normal. None of the studied polymorphisms was associated with the risk for migraine.
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.
In 2020 dimethyl sulfoxide (DMSO), the ever‐present solvent for tin halide perovskites, was identified as an oxidant for SnII. Nonetheless, alternatives are lacking and few efforts have been devoted ...to replacing it. To understand this trend it is indispensable to learn the importance of DMSO on the development of tin halide perovskites. Its unique properties have allowed processing compact thin‐films to be integrated into tin perovskite solar cells. Creative approaches for controlling the perovskite crystallization or increasing its stability to oxidation have been developed relying on DMSO‐based inks. However, increasingly sophisticated strategies appear to lead the field to a plateau of power conversion efficiency in the range of 10–15 %. And, while DMSO‐based formulations have performed in encouraging means so far, we should also start considering their potential limitations. In this concept article, we discuss the benefits and limitations of DMSO‐based tin perovskite processing.
A dead‐end for DMSO? The crystallization of tin halide perovskites into thin‐films is uncontrolled. The strongly‐binding solvent DMSO and its tolerance to additives helped here. However, device performance stagnates around 10–15 %. The oxidation of tin by DMSO could explain this. Efforts to substitute it are promising, but still lag behind. Addressing solution properties from a fundamental perspective will allow developing DMSO‐free systems.
Interfaces in thin‐film photovoltaics play a pivotal role in determining device efficiency and longevity. In this work, the top surface treatment of mixed tin–lead (≈1.26 eV) halide perovskite films ...for p–i–n solar cells is studied. Charge extraction is promoted by treating the perovskite surface with piperazine. This compound reacts with the organic cations at the perovskite surface, modifying the surface structure and tuning the interfacial energy level alignment. In addition, the combined treatment with C60 pyrrolidine tris‐acid (CPTA) reduces hysteresis and leads to efficiencies up to 22.7%, with open‐circuit voltage values reaching 0.90 V, ≈92% of the radiative limit for the bandgap of this material. The modified cells also show superior stability, with unencapsulated cells retaining 96% of their initial efficiency after >2000 h of storage in N2 and encapsulated cells retaining 90% efficiency after >450 h of storage in air. Intriguingly, CPTA preferentially binds to Sn2+ sites at film surface over Pb2+ due to the energetically favored exposure of the former, according to first‐principles calculations. This work provides new insights into the surface chemistry of perovskite films in terms of their structural, electronic, and defect characteristics and this knowledge is used to fabricate state‐of‐the‐art solar cells.
Synergistic surface modification of mixed Sn–Pb perovskite films by the combination of piperazine and C60 pyrrolidine tris‐acid realizes narrow‐bandgap solar cells with power conversion efficiencies up to 22.7% and substantially elongated stability.
A variety of novel chemically modified fullerenes, showing different electron‐accepting capabilities, has been synthesized and used to prepare electron transport layer (ETL)‐free solar cells based on ...perovskite/fullerene blends. In particular, isoxazolino60 fullerenes are proven to be a good candidate for processing blend films with CH3NH3PbI3 and obtaining enhanced power conversion efficiency (PCE) ETL‐free perovskite solar cells (PSCs), improving the state‐of‐the‐art PCE (i.e., 14.3 %) for this simplified device architecture. A beneficial effect for pyrazolino and methano60fullerene derivatives versus pristine 60/fullerene is also shown. Furthermore, a clear correlation between the LUMO energy level of the fullerene component and the open circuit voltage of the solar cells is found. Apart from the new knowledge on innovative fullerene derivatives for PSCs, the universality and versatility of perovskite/fullerene blend films to obtain efficient ETL‐free PSCs is demonstrated.
Blending things up: New CH3NH3PbI3/fullerene blends based on a variety of fullerene derivatives (i.e., isoxazolino, pyrazolino, and methano60fullerenes) are demonstrated for the fabrication of electron transport layer‐free solar cells that efficiently (i.e., up to 14.3 %) convert sunlight into electricity.
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