Lead Isolation and Capture in Perovskite Photovoltaics toward Eco-Friendly Commercialization.

Perovskite solar cells (PSCs) are developed rapidly in efficiency and stability in recent years, which can compete with silicon solar cells. However, an important obstacle to the commercialization of PSCs is the toxicity of lead ions (Pb2+) from water-soluble perovskites. The entry of free Pb2+ into organisms can cause severe harm to humans, such as blood lead poisoning, organ failure, etc. Therefore, this work reports a "lead isolation-capture" dual detoxification strategy with calcium disodium edetate (EDTA Na-Ca), which can inhibit lead leakage from PSCs under extreme conditions. More importantly, leaked lead exists in a nontoxic aggregation state chelated by EDTA. For the first time, in vivo experiments are conducted in mice to systematically prove that this material has a significant inhibitory effect on the toxicity of perovskites. In addition, this strategy can further enhance device performance, enabling the optimized devices to achieve an impressive power conversion efficiency (PCE) of 25.19%. This innovative strategy is a major breakthrough in the research on the prevention of lead toxicity in PSCs.

Palladium-Catalyzed Carbonylation Reaction of Indole/Pyrrole Involving HCFO-1233zd (E).

3-Indole-3-one is a key intermediate in the synthesis of many drugs and plays an important role in synthetic chemistry and biochemistry. A new method for synthesizing trifluoromethylated 3-indoleketones by Pd(0)-catalyzed carbonylation was introduced. In the absence of additives, 1-chloro-3,3,3-trifluoropropyl (an inexpensive and environmentally friendly synthetic block of trifluoromethyl) reacts with indole and carbon monoxide to generate trifluoromethylindole ketones with good yields, regioselectivity, and chemical selectivity; furthermore, the products exhibit strong resistance to basic functional groups, such as alkynes, aldehydes, and esters. In addition to the conversion of indole compounds into corresponding products, pyrrole and heteroindole may be suitable for corresponding chemical transformations. This study provides a synthetic method for the further construction of trifluoromethylated 3-indole ketones.

Ion-Dipole Interaction Enabling Highly Efficient CsPbI3 Perovskite Indoor Photovoltaics.

Metal halide perovskites are ideal candidates for indoor photovoltaics (IPVs) because of their easy-to-adjust bandgaps, which can be designed to cover the spectrum of any artificial light source. However, the serious non-radiative carrier recombination under low light illumination restrains the application of perovskite-based IPVs (PIPVs). Herein, polar molecules of amino naphthalene sulfonates are employed to functionalize the TiO2 substrate, anchoring the CsPbI3 perovskite crystal grains with a strong ion-dipole interaction between the molecule-level polar interlayer and the ionic perovskite film. The resulting high-quality CsPbI3 films with the merit of defect-immunity and large shunt resistance under low light conditions enable the corresponding PIPVs with an indoor power conversion efficiency of up to 41.2% (Pin : 334.11 µW cm-2 , Pout : 137.66 µW cm-2 ) under illumination from a commonly used indoor light-emitting diode light source (2956 K, 1062 lux). Furthermore, the device also achieves efficiencies of 29.45% (Pout : 9.80 µW cm-2 ) and 32.54% (Pout : 54.34 µW cm-2 ) at 106 (Pin : 33.84 µW cm-2 ) and 522 lux (Pin : 168.21 µW cm-2 ), respectively.

Low-Dimensional Phase Regulation to Restrain Non-Radiative Recombination for Sky-Blue Perovskite LEDs with EQE Exceeding 15 .

Achieving efficient blue electroluminescence (EL) remains the fundamental challenge that impedes perovskite light-emitting diodes (PeLEDs) towards commercial applications. The bottleneck accounting for the inefficient blue PeLEDs is broadly attributed to the poor-emissive blue perovskite emitters based on either mixed halide engineering or reduced-dimensional strategy. Herein, we report the high-performing sky-blue PeLEDs (490 nm) with the maximum EQE exceeding 15 % by incorporating a molecular modifier, namely 4,4'-Difluorophenone, for significantly suppressing the non-radiative recombination and tuning of the low-dimensional phase distribution of quasi-2D blue perovskites, which represents a remarkable paradigm for developing the new generation of blue lighting sources.

Light-Triggered Sustainable Defect-Passivation for Stable Perovskite Photovoltaics.

The generation of photoinduced defects and freely moving halogen ions is dynamically updated in real time. Accordingly, most reported strategies are static and short-term, which make their improvements in photostability very limited. Therefore, seeking new passivation strategies to match the dynamic characteristics of defect generation is very urgent. Without newly generated defects, a passivation molecule should exist in the configuration that would not become the initiation sites for defect generation. With newly generated defects, the passivation molecule should transfer into the other configuration that possesses the passivation sites. Herein, a classical photoisomeric molecule, spiropyran, is adopted, whose pre- and post-isomeric forms meet the requirements for two different configurations, to realize the state transition once the photoinduced defects appear during subsequent operation and dynamic capture for continuous renewal of defects. Consequently, spiropyrans work as light-triggered and self-healing sustainable passivation sites to realize continuous defect repair. The target devices retain 93% and 99% of their initial power conversion efficiencies after 456 h aging under ultraviolet illumination and 1200 h aging under full-spectrum illumination, respectively. This work provides a novel concept of sustainable passivation strategy to realize continuous defect-passivation and film-healing in perovskite photovoltaics.

Visualizing the Surface Photocurrent Distribution in Perovskite Photovoltaics.

Defect states play an important role in the photovoltaic performance of metal halide perovskites. Particularly, the passivation of surface defects has made great contributions to high-performance perovskite photovoltaics. This highlights the importance of understanding the surface defects from a fundamental level by developing more accurate and operando characterization techniques. Herein, a strategy to enable the surface carriers and photocurrent distributions on perovskite films to be visualized in the horizontal direction is put forward. The visual image of photocurrent distribution is realized by combining the static local distribution of carriers provided by scanning near-field optical microscopy with the dynamic transporting of carriers achieved via a scanning photocurrent measurement system. Taking a surface passivated molecule as an example, a comprehensive defect scene including static and dynamic as well as local and entire conditions is obtained using this strategy. The comprehensive analysis of the trap states in perovskite films is pioneered vertically and horizontally, which will powerfully promote the deep understanding of defect mechanisms and carrier behavior for the goal of fabricating high-performance perovskite optoelectronic devices.

Full-Dimensional Grain Boundary Stress Release for Flexible Perovskite Indoor Photovoltaics.

Perovskite photovoltaics are strong potential candidates to drive low-power off-grid electronics for indoor applications. Compared with rigid devices, flexible perovskite devices can provide a more suitable surface for indoor small electronic devices, enabling them have a broader indoor application prospect. However, the mechanical stability of flexible perovskite photovoltaics is an urgent issue solved. Herein, a kind of 3D crosslinking agent named borax is selected to carry out grain boundary penetration treatment on perovskite film to realize full-dimensional stress release. This strategy improves the mechanical and phase stabilities of perovskite films subjected to external forces or large temperature changes. The fabricated perovskite photovoltaics deliver a champion power conversion efficiency (PCE) of 21.63% under AM 1.5G illumination, which is the highest one to date. The merit of low trap states under weak light makes the devices present a superior indoor PCE of 31.85% under 1062 lux (LED, 2956 K), which is currently the best flexible perovskite indoor photovoltaic device. This work provides a full-dimensional grain boundary stress release strategy for highly stable flexible perovskite indoor photovoltaics.

Cedrol induces autophagy and apoptotic cell death in A549 non-small cell lung carcinoma cells through the P13K/Akt signaling pathway, the loss of mitochondrial transmembrane potential and the generation of ROS.

The objective of the present study was to determine the anticancer effects of cedrol in A549 human non-small cell lung cancer cells by examining the effects of cedrol on apoptosis induction, the phosphatidylinositol 3'-kinase (PI3K)/Akt signaling pathway, autophagy, reactive oxygen species (ROS) generation and mitochondrial transmembrane potential (MTP). The anticancer effects of cedrol were examined using A549 human lung carcinoma cells as an in vitro model. Cell viability was determined using MTT and lactate dehydrogenase (LDH) assays, and an inverted phase contrast microscope was used to examine the morphological changes in these cells. Cedrol­triggered autophagy was confirmed by transmission electron microscopy (TEM) analysis of the cells, as well as by western blot analysis of microtubule-associated protein light-chain 3 (LC3)B expression. Intracellular ROS generation was measured by flow cytometry using 5-(6)-carboxy-2',7'-dichlorodihydrofluorescein diacetate (CM-DCFH2-DA) staining and MTP was measured using flow cytometry. The results demonstrated that cedrol reduced cell viability and induced cell apoptosis in a dose-dependent manner. Mechanistic evaluations indicated that cedrol induced apoptosis by reducing the MTP and by decreasing the levels of phosphorylated (p-)PI3K and p-Akt. Cedrol induced autophagy, which was confirmed by TEM analysis, by increasing intracellular ROS formation in a concentration-dependent manner, which was almost completely reversed by N-acetyl-L-cysteine (NAC) and tocopherol. Taken together, these findings reveal that cedrol inhibits cell proliferation and induces apoptosis in A549 cells through mitochondrial and PI3K/Akt signaling pathways. Our findings also reveal that cedrol induced pro-death autophagy by increasing intracellular ROS production.

[Clinical study of the predictors to neoadjuvant chemotherapy in patients with advanced gastric cancer].

OBJECTIVE: To investigate the predictive value of seven gastric cancer-associated factors on neoadjuvant chemotherapy in patients with advanced gastric cancer. METHODS: Expressions of C-met, EGFR, HER2, Ki-67, MMP7, P53 and TOPOII were detected by immunohistochemistry in gastric cancer tissues of 53 cases before and after mFOLFOX7 neoadjuvant chemotherapy. Chemotherapy efficacy was evaluated according to RECIST 1.1 standard combined with histopathology, and the relationship between various genes and chemotherapy efficacy was analyzed by univariate and logistic multivariate regression analyses. RESULTS: The clinical response rate was 52.8% (28/53) in neoadjuvant chemotherapy, including complete response in none, partial response in 28 cases (52.8%), stable disease in 24 cases (45.3%) and progressive disease in 1 case (1.9%). The expressions of all the genes were not significantly different before and after neoadjuvant chemotherapy (P>0.05). Neoadjuvant chemotherapy efficacy was 83.3% (10/12) in the patients of HER2 positive expression and 43.9% (18/41) in the patients of HER2 negative expression. The former was significant higher than the latter (P=0.016). Response rate of patients with P53 positive expression was 35.7% (10/28), significantly lower than 72.0% (18/25) of those with P53 negative expression (P=0.008). Six patients with both HER2 positive expression and P53 negative expression showed better efficacy. The expressions of C-met, EGFR, Ki-67, MMP7 and TOPOII were not associated with response to neoadjuvant chemotherapy (P>0.05). HER2 and P53 were independent influencing factors of neoadjuvant chemotherapy (P<0.05). CONCLUSION: Expressions of HER2 and P53 have great value in the prediction of mFOLFOX7 neoadjuvant chemotherapy efficacy, suggesting that as independent factors, HER2 and P53 may be used to predict the efficacy before chemotherapy.

[A clinical study of paclitaxel combined with FOLFOX4 regimen as neoadjuvant chemotherapy for advanced gastric cancer].

OBJECTIVE: To evaluate the clinical efficacy and the toxicity of neoadjuvant chemotherapy with paclitaxel and FOLFOX4 (5-fluorouracil/leucovorin combined and oxaliplatin) regimen for advanced gastric cancer. METHODS: Seventy-eight patients with cTNM stage III or IV (M0) gastric cancer were enrolled and 39 were randomized into the treatment arm (n=39, paclitaxel combined with FOLFOX4 regimen neoadjuvant chemotherapy every two weeks in each cycle) and control group (n=39). Clinical response was evaluated with RECIST criteria after 3 cycles. Patients in experimental group received surgery after 2-4 weeks and postoperative chemotherapy of 3 cycles of the original regimen. When disease progressed, postoperative chemotherapy regimen was changed into ECF regimen. The control group of 39 patients received surgery within 2 weeks and postoperative chemotherapy of 6 cycles of paclitaxel combined with FOLFOX4 regimen. RESULTS: The clinical response rate was 66.7% in the treatment arm. The R0 resection rate (59.0%) was significantly higher than that in the control group (P=0.025) and the number of lymph node metastasis in the treatment arm(3.23±2.80) was significantly lower than that in the control group (5.79±2.69, P=0.001). There were no significant differences in postoperative complication rate (5.1% vs. 2.6%) and the number of lymph node dissection (19.69±2.95 vs. 20.59±3.22) between the two groups (P>0.05). The median survival time and 2-year survival rate in the treatment arm [(27.10±2.32) months and 59.0%] was significantly higher than that in the control group[(18.20±1.30) months and 28.2%] (P=0.001, P=0.006). Cox regression multivariable analysis showed that tumor differentiation, R0 resection, lymph node metastasis were independent prognostic factors. Adverse reaction of chemotherapy, mainly hematological adverse reactions, and peripheral nerve toxicity, were tolerable. No significant differences were noted between the two groups in adverse reactions (P>0.05). CONCLUSIONS: The efficacy of paclitaxel combined with FOLFOX4 as neoadjuvant chemotherapy is high. Patients tolerance and compliance are satisfactory. It can improve in patients with advanced gastric cancer the R0 resection rate, reduce lymph node metastasis and improve survival.