Stronger Coupling of Quantum Dots in Hole Transport Layer Through Intermediate Ligand Exchange to Enhance the Efficiency of PbS Quantum Dot Solar Cells.

Nowadays, the extensively used lead sulfide (PbS) quantum dot (QD) hole transport layer (HTL) relies on layer-by-layer method to replace long chain oleic acid (OA) ligands with short 1,2-ethanedithiol (EDT) ligands for preparation. However, the inevitable significant volume shrinkage caused by this traditional method will result in undesired cracks and disordered QD arrangement in the film, along with adverse increased defect density and inhomogeneous energy landscape. To solve the problem, a novel method for EDT passivated PbS QD (PbS-EDT) HTL preparation using small-sized benzoic acid (BA) as intermediate ligands is proposed in this work. BA is substituted for OA ligands in solution followed by ligand exchange with EDT layer by layer. With the new method, smoother PbS-EDT films with more ordered and closer QD packing are gained. It is demonstrated stronger coupling between QDs and reduced defects in the QD HTL owing to the intermediate BA ligand exchange. As a result, the suppressed nonradiative recombination and enhanced carrier mobility are achieved, contributing to ≈20% growth in short circuit current density (Jsc) and a 23.4% higher power conversion efficiency (PCE) of 13.2%. This work provides a general framework for layer-by-layer QD film manufacturing optimization.

Simultaneous Passivation of Perovskite Interfaces at Multiple Active Sites Improves Device Performance: Combining Theory and Experiment.

A multisite interface passivation material named 2-mercapto-4-methyl-5-thiazoleacetic acid (MMTA) is used to optimize the perovskite film top interface. DFT calculations and experiments show that MMTA can effectively passivate interface defects. Finally, the champion device's photoelectric conversion efficiency reached 23.44%, which possessed long-term stability.

Ferrocene Derivatives for Improving the Efficiency and Stability of MA-Free Perovskite Solar Cells from the Perspective of Inhibiting Ion Migration and Releasing Film Stress.

Further improvement of the performance and stability of inverted perovskite solar cells (PSCs) is necessary for commercialization. Here, ferrocene derivative dibenzoylferrocene (DBzFe) is used as an additive to enhance the performance and stability of MA- and Br- free PSCs. The results show that the introduction of DBzFe not only passivates the defects in the film but also inhibits the ion migration in the film. The final device achieves a power conversion efficiency (PCE) of 23.53%, which is one of the highest efficiencies currently based on self-assembled monolayers (SAMs). Moreover, it maintains more than 96.4% of the original efficiency when running continuously for 400 h at the maximum power point.

Efficiency Enhancement of Wide Bandgap Lead Perovskite Solar Cells with PTAA Surface-Passivated with Monomolecular Layer from the Viewpoint of PTAA Band Bending.

This report is on the efficiency enhancement of wide bandgap lead halide perovskite solar cells (WBG Pb-PVK PSCs) consisting of FA0.8Cs0.2PbI1.8Br1.2 as the light-harvesting layer. WGB Pb-PVK PSCs have attracted attention as the top layer of all perovskite-tandem solar cells. Poly[bis(4-phenyl) (2,4,6-trimethylphenyl) amine] (PTAA), a conductive polymer, is always used as the hole transporting layer (HTL) for Pb-PVK PSCs. Nevertheless, the hydrophobic surface of the PTAA sometimes destroys the growth of the FA0.8Cs0.2PbI1.8Br1.2 film. On the other hand, the Fermi level of PTAA is not well matched with that of perovskite film. Thus, the PCE of the WBG Pb-based PSCs with PTAA as the HTL was not very high. In this report, the efficiency of the FA0.8Cs0.2PbI1.8Br1.2 is improved by passivating the surface of the PTAA with a monomolecular layer, where the surface becomes hydrophilic, and the band bending of the PTAA layer is improved to cause swift hole collection. Finally, WBG Pb-PVK PSCs (1.77 eV) with 16.52% efficiency are reported.

Ssc-mir-221-3p regulates melanin production in Xiang pigs melanocytes by targeting the TYRP1 gene.

BACKGROUND: MicroRNAs (miRNAs) are small endogenous non-coding RNAs that regulate gene expression by down-regulating it. Several studies have suggested that miRNAs plays a crucial role in mammalian skin color production. The TYRP1 gene, a member of the tyrosine family, is an important candidate gene that affects melanogenesis. This study aimed to identify genes and miRNAs that affect melanin production in Xiang pigs by transcriptome sequencing, and to validate their targeted regulatory relationships. RESULTS: 17 miRNAs and 1,230 genes were significantly differentially expressed (P < 0.05) in the black and white skin tissues of Jianbai Xiang pigs. miRNA-221-3p was identified as a candidate miRNA for melanin formation and its target gene, TYRP1, was selected. The TYRP1 gene is a member of the TYR gene family, which evolved from the TYR gene through chromosome segmental duplication. The function of the gene was highly conserved throughout the evolutionary process. overexpression of TYRP1 gene significantly increased the expression of TYR, TYRP1, and DCT genes P < 0.01, which led to an increase in the relative content of melanin. Silencing of TYRP1 through the use of TYRP1-siRNA significantly reduced the expression of TYR, TYRP1, and DCT genes in Jianbai Xiang pig melanocytes P < 0.01, which in turn decreased the relative melanin content. The targeted binding relationship between ssc-miR-221-3p and TYRP1 gene was validated. After transfection of porcine melanocytes with ssc-miR-221-3p mimic, the expression of ssc-miR-221-3p was significantly up-regulated (P < 0.01). Furthermore, the mRNA and protein levels of TYR, TYRP1, and DCT genes were significantly down-regulated (P < 0.01), and melanin content in cells was significantly reduced (P < 0.01). CONCLUSION: The TYRP1 gene affects melanogenesis in melanocytes of Jianbai Xiang pigs, and ssc-miR-221-3p targets the TYRP1 gene to regulate melanogenesis in melanocytes of Jianbai Xiang pigs.

14.31 % Power Conversion Efficiency of Sn-Based Perovskite Solar Cells via Efficient Reduction of Sn4.

The photoelectric properties of nontoxic Sn-based perovskite make it a promising alternative to toxic Pb-based perovskite. It has superior photovoltaic performance in comparison to other Pb-free counterparts. The facile oxidation of Sn2+ to Sn4+ presents a notable obstacle in the advancement of perovskite solar cells that utilize Sn, as it adversely affects their stability and performance. The study revealed the presence of a Sn4+ concentration on both the upper and lower surfaces of the perovskite layer. This discovery led to the adoption of a bi-interface optimization approach. A thin layer of Sn metal was inserted at the two surfaces of the perovskite layer. The implementation of this intervention yielded a significant decrease in the levels of Sn4+ and trap densities. The power conversion efficiency of the device was achieved at 14.31 % through the optimization of carrier transportation. The device exhibited operational and long-term stability.

Effects of rotted corn straw on soil environment, yield, and quality of cucumber.

Aiming at solving the problems of soil environment deterioration and the decline of both yield and quality caused by excessive application of chemical fertilizer, we investigated the effects of rotted corn straw on the soil environment of root zone, yield and quality of cucumber with 'Jinyou 35' cucumber as the experimental material. There were three treatments, namely, combined application of rotted corn straw and chemical fertilizer (T1, the total nitrogen fertilizer application were 450 kg N·hm-2, of which 9000 kg·hm-2 rotted corn straw was used as the subsoil fertilizer, and the rest was supplemented with chemical fertilizer), pure chemical fertilizer (T2, the total nitrogen fertilizer application was the same as T1) and no fertilization (control). The results showed that the content of soil organic matter in root zone soil in T1 treatment was much higher, but no difference between T2 treatment and the control, after two continuous plantings in one year. The concentrations of soil alkaline nitrogen, available phosphorus, available potassium of T1 and T2 in cucumber root zone were higher than that in the control. T1 treatment had lower bulk density, but markedly higher porosity and respiratory rate than T2 treatment and the control in root zone soil. The electric conductivity of T1 treatment was higher than that of the control, but significantly lower than T2 treatment. There was no significant difference in pH among the three treatments. The quantity of bacteria and actinomycetes in cucumber rhizosphere soil were the highest in T1, and the lowest in the control. However, the highest quantity of fungi was found in T2. The enzyme activities of rhizosphere soil in T1 treatment were markedly higher than those of the control, whereas those of T2 treatment were significantly lower or had no significant difference relative to the control. The cucumber root dry weight and root activity of T1 were significantly higher than that of the control. The yield of T1 treatment increased by 10.1%, and fruit quality improved obviously. The root activity of T2 treatment was also significantly higher than that in the control. There was no significant difference in root dry weight and yield between T2 treatment and the control. Furthermore, T2 treatment revealed a decrease in fruit quality relative to T1 treatment. These results suggested that the combined application of rotted corn straw and chemical fertilizer could improve soil environment, promote root growth, enhance root activity and improve yield and quality of cucumber in solar-greenhouse, which could be popularized and applied in protected cucumber production.

Comparative transcriptome analysis of grafting to improve chilling tolerance of cucumber.

Grafting with pumpkin as rootstock could improve chilling tolerance of cucumber; however, the underlying mechanism of grafting-induced chilling tolerance remains unclear. Here, we analyzed the difference of physiological and transcriptional level between own-rooted (Cs/Cs) and hetero-grafted (Cs/Cm) cucumber seedlings under chilling stress. The results showed that grafting with pumpkin significantly alleviated the chilling injury as evidenced by slightly symptoms, lower contents of electrolyte leakage (EL), malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion (O2-) and higher relative water content in Cs/Cm seedlings compared with Cs/Cs seedlings under chilling stress. RNA-seq data showed that grafting induced more DGEs at 8 °C/5 °C compared with 25 °C/18 °C. In accordance with the increase of the activities of antioxidant enzymes (SOD, POD, CAT, APX), grafting upregulated the expression of the regulated redox-related genes such as GST, SOD, and APX. Moreover, grafting increased the expression of genes participated in central carbon metabolism to promote the conversion and decomposition of sugar, which provided more energy for the growth of Cs/Cm seedlings under chilling stress. In addition, grafting regulated the genes involved in the intracellular signal transduction pathways such as calcium signal (CAML, CML, and CDPK) and inositol phospholipid signal (PLC), as well as changed the gene expression of plant hormone signal transduction pathways (ARF, GAI, ABF, and PYR/PYL). These results provide a physiological and transcriptional basis for the molecular mechanism of grafting-induced chilling tolerance of cucumber seedlings.

Protectin Conjugates in Tissue Regeneration 1 Inhibits Macrophage Pyroptosis by Restricting NLRP3 Inflammasome Assembly to Mitigate Sepsis via the cAMP-PKA Pathway.

Protectin conjugates in tissue regeneration 1 (PCTR1) is a novel anti-inflammatory and proresolving lipid mediator biosynthesized from docosahexaenoic acid. Excessive activation of NLR family pyrin domain containing 3 (NLRP3) inflammasome and consequent pyroptosis are involved in diverse inflammatory diseases. However, how PCTR1 affects NLRP3 inflammasome activation and pyroptosis are still unclear. Here, we demonstrated that PCTR1 inhibited NLRP3 inflammasome activation and pyroptosis. These results show that PCTR1 dose-dependently inhibited gasdermin D cleavage in lipopolysaccharide (LPS)-primed murine primary macrophages upon nigericin stimulation. Additionally, PCTR1 treatment after LPS priming inhibited caspase-1 activation and subsequent mature interleukin-1ß release independent of the nuclear factor-kappa B pathway. PCTR1 exerted its inhibitory effects by blocking NLRP3-apoptosis-associated speck-like protein containing a CARD (ASC) interaction and ASC oligomerization, thereby restricting NLRP3 inflammasome assembly. However, the inhibitory effect of PCTR1 could be reversed by KH7 and H89, which are the inhibitors of the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) signaling pathway. Moreover, PCTR1 treatment alleviated lung tissue damage and improved mouse survival in LPS-induced sepsis. Our study unveils the molecular mechanism of negative regulation of NLRP3 inflammasome activation and pyroptosis by a novel lipid mediator and suggests that PCTR1 may serve as a potential treatment option for NLRP3-inflammasome driven diseases.

Functionalized polymer modified buried interface for enhanced efficiency and stability of perovskite solar cells.

Although great progress has been made in perovskite solar cells (PCSs), further development of PCSs is hindered by a large number of defects, nonradiative recombination, and mysterious stresses. Here, we propose a new interfacial strategy by introducing a new polymer material named povidone-iodine (PV-I) as a buffer layer. A series of studies indicate that the introduced buffer layer can form a strong chemical interaction with SnO2 and the perovskite, which can not only passivate the defects of the two functional layers but also strengthen the interfacial connection. The reduction of film defects and the enhancement of interface connection are beneficial to the extraction and transport of the carrier. In addition, the introduction of a buffer layer releases the interfacial stress. Ultimately, we achieved attractive efficiency (22.02%, 0.1 cm2) and considerable long-term stability (after aging 500 h, the target device still retains 81% of its original PCE). The excellent performance of the device indicates that this strategy can be used as an effective control method for perovskite solar cells to facilitate their commercialization.

Biosynthetic pathway of prescription bergenin from Bergenia purpurascens and Ardisia japonica.

Bergenin is a typical carbon glycoside and the primary active ingredient in antitussive drugs widely prescribed for central cough inhibition in China. The bergenin extraction industry relies on the medicinal plant species Bergenia purpurascens and Ardisia japonica as their resources. However, the bergenin biosynthetic pathway in plants remains elusive. In this study, we functionally characterized a shikimate dehydrogenase (SDH), two O-methyltransferases (OMTs), and a C-glycosyltransferase (CGT) involved in bergenin synthesis through bioinformatics analysis, heterologous expression, and enzymatic characterization. We found that BpSDH2 catalyzes the two-step dehydrogenation process of shikimic acid to form gallic acid (GA). BpOMT1 and AjOMT1 facilitate the methylation reaction at the 4-OH position of GA, resulting in the formation of 4-O-methyl gallic acid (4-O-Me-GA). AjCGT1 transfers a glucose moiety to C-2 to generate 2-Glucosyl-4-O-methyl gallic acid (2-Glucosyl-4-O-Me-GA). Bergenin production ultimately occurs in acidic conditions or via dehydration catalyzed by plant dehydratases following a ring-closure reaction. This study for the first time uncovered the biosynthetic pathway of bergenin, paving the way to rational production of bergenin in cell factories via synthetic biology strategies.

[Alleviating effect of exogenous melatonin and calcium on the peroxidation damages of cucumber under high temperature stress]. / å¤–æºè¤ªé»‘ç´ ä¸Žé’™ç¦»å­äº’ä½œå¯¹é«˜æ¸©èƒè¿«ä¸‹é»„ç“œå¹¼è‹—è¿‡æ°§åŒ–ä¼¤å®³çš„ç¼“è§£æ•ˆåº”.

To explore whether there is an interaction between melatonin (MT) and calcium (Ca2+) in regulating heat tolerance of plants, we analyzed the response of endogenous MT and Ca2+ to heat stress, and examined the effect of MT and Ca2+ on the reactive oxygen (ROS) accumulation, antioxidant system, and transcripts of heat shock factor (HSF) and heat shock proteins (HSPs) of cucumber seedlings under high temperature stress. Seedlings were foliar sprayed with 100 µmol·L-1 MT, 10 mmol·L-1 CaCl2, 3 mmol·L-1 ethylene glycol tetraacetic acid (EGTA, Ca2+ chelating agent) +100 µmol·L-1 MT, 0.05 mmol·L-1 chlorpromazine (calmodulin antagonist, CPZ) +100 µmol·L-1 MT, 100 µmol·L-1 p-chlorophenylalanine (p-CPA, inhibitor of MT) +10 mmol·L-1 CaCl2 or deionized water (H2O), respectively. The results showed that both endogenous MT and Ca2+ in cucumber seedlings were induced by high temperature stress. The seedlings treated with exogenous MT showed significant increases in the mRNA expression of calmodulin (CaM), calcium-dependent protein kinase (CDPK5), calcineurin B-like protein (CBL3) and CBL interacting protein kinase (CIPK2) compared with the control at normal temperature. The mRNA levels of tryptophane decarboxylase (TDC), 5-hydroxytryptamine-N-acetyltransferase (SNAT) and N-acetyl-5-hydroxytryptamine methyltransferase (ASMT), key genes of MT biosynthesis and endogenous MT content were also induced by Ca2+ in cucumber seedlings. Exogenous MT and CaCl2 alleviated the heat-induced oxidative damage through increasing antioxidant ability, reducing the accumulation of reactive oxygen species (ROS), and upregulating the mRNA abundances of HSF7, HSP70.1 and HSP70.11, as evidenced by mild thermal damage symptoms, lower heat injury index and electrolyte leakage under heat stress. The positive effect of MT-induced antioxidant capacity and mRNA expression of HSPs was removed by adding EGTA and CPZ in stressed seedlings. Similarly, the mitigating role of Ca2+ in the peroxidation damage to high temperature stress was reversed by p-CPA. These results suggested that both MT and Ca2+ could induce heat tolerance of cucumber seedlings, which had crosstalk in the process of heat stress signal transduction.

In situ lead oxysalt passivation layer for stable and efficient perovskite solar cells.

A Rb2SO4 additive is employed to passivate the Pb2+ defects in a perovskite film by forming PbSO4in situ, which can cover the surface and grain boundaries of the perovskite to ensure that the film is not decomposed by moisture. Finally, a device based on the Rb2SO4 modification achieved an enhanced power conversion efficiency (22.25%) and long-term stability.

[Effect of manual acupuncture at "Sanyinjiao" (SP6) on spermatogenic cells of mice with oligoasthenospermia induced by microwave radiation].

OBJECTIVE: To observe the effect of acupuncture at "Sanyinjiao" (SP6) on sperm motility, testicular B cell lymphoma/leukelia-2 (Bcl-2), Bcl-2 associated X protein (Bax), and Caspase-3 in mice with oligoasthenospermia induced by microwave radiation, so as to explore its underlying mechanisms in improving oligoasthenospermia. METHODS: Male BALB/C mice were randomly divided into control, model and acupuncture groups(n=6 in each group). The oligoasthenospermia model was established by continuous microwave irradiation with frequency of 2 450 MHz and power density of 40 mW/cm2, 1 h daily for 18 days. At the same time, manual acupuncture was applied to the acupuncture group on bilateral "Sanyinjiao" (SP6) for 30 s, once daily for 18 days. Sperm motility including the percentages of progressive motility (PR), non-progressive motility (NP), and PR + NP sperms was detected by computer-assisted sperm analysis, H.E. staining was used to observe the testicular morphology and Johnson score was calculated, the expression levels of Bcl-2, Bax and Caspase-3 in testis were detected by immunofluorescence. RESULTS: Compared with the control group, the percentages of PR sperms, NP sperms, PR+NP sperms, Johnson score, and expression level of Bcl-2 were significantly decreased (P<0.05), while the expression levels of Bax and Caspase-3 were increased (P<0.05) in the model group. Compared with the model group, the percentages of PR sperms, PR+NP sperms, Johnson score, and expression level of Bcl-2 were significantly increased (P<0.05), while the expression levels of Bax and Caspase-3 were decreased (P<0.05) in the acupuncture group. Outcomes of H.E. staining showed that the seminiferous tubules became thinner, spermatogenic cells and sperm decreased or even disappeared, and the supporting cells were partially missing in the model group, which was relatively milder in the acupuncture group. CONCLUSION: Manual acupuncture at SP6 can improve sperm motility in oligoasthenospermia mice induced by microwave radiation, which may be related to its effects in down-regulating the expressions of Bax and Caspase-3, increasing expression of Bcl-2 in the testis.

Multistrategy Preparation of Efficient and Stable Environment-Friendly Lead-Based Perovskite Solar Cells.

Perovskite solar cells (PSCs) have achieved huge success in power conversion efficiency (PCE) and stability. However, further improving the PCE of PSCs and stability is still a big challenge. Here, we attempt to improve the PCE and stability of PSCs using a functional additive named 3-mercaptopropyltriethoxysilane (SiSH) in the perovskite antisolvent. It is revealed that SiSH can release the stress in the film, reduce the defects, and inhibit lithium-ion migration and lead leakage. As a result, the target device achieves an efficiency enhancement from 20.80 to 22.42% as compared to the control device. Meanwhile, device stability is ameliorated after SiSH modification. Furthermore, new adsorbents are used to treat the leaked lead to make it comply with safe drinking water standards. This work provides an idea for developing multifunctional antisolvent additives and adsorbents for high PCE, long stability, and environment-friendly Pb-based PSCs.

[Effects of fulvic acid on photosynthetic characteristics, yield and quality of cucumber under drought stress]. / é»„è é ¸å¯¹å¹²æ—±èƒè¿«ä¸‹é»„ç“œå ‰åˆç‰¹æ€§åŠäº§é‡å’Œå“è´¨çš„å½±å“.

Fulvic acid (FA) participates in the regulation of drought stress tolerance in plants, but the underlying mechanisms remain unclear. We carried out an experiment with cucumber cultivar 'Jinyou 35' as the test material and the polyethylene glycol (PEG-6000) being used to simulate drought stress. The concentration effect of FA on drought alleviation of cucumber as well as the effect of FA on photosynthetic enzymes activities, chloroplast ultrastructure, fluorescence parameters, water use efficiency, yield and quality of cucumber plants were studied through spraying FA with different concentrations (0, 100, 300, 500, 700 and 900 mg·L-1). The results showed that FA with different concentrations significantly promoted the relative water content and leaf area and decreased drought injure index as well as the electrolyte leakage and malondialdehyde (MDA) content, compared with the control (0 mg·L-1) under drought stress. The mitigative effect of FA increased first and then decreased with the increases of FA concentration, with 700 mg·L-1 FA showing the best effect. FA significantly enhanced the chlorophyll content, Rubiasco and Rubisco activase (RCA) activities and gene expression, net photosynthesis (Pn), maximal photochemical efficiency of PSⅡin darkness, actual photochemical efficiency, absorbed light energy per unit area, captured light energy per unit area, quantum yield of electron transport and PSⅠ activity, decreased the increase of K point and maintained chloroplast ultrastructure. The experiment in solar-greenhouse showed that FA obviously increased water use efficiency, promoted dry matter accumulation as well as the contents of Vc, soluble sugar, soluble protein and free amino acid, and decreased tannin content. Our results suggested that FA could improve the yield and quality of cucumber in solar greenhouse under drought stress.

Salicylic Acid Is Involved in Rootstock-Scion Communication in Improving the Chilling Tolerance of Grafted Cucumber.

Salicylic acid (SA) has been proven to be a multifunctional signaling molecule that participates in the response of plants to abiotic stresses. In this study, we used cold-sensitive cucumber and cold-tolerant pumpkin as experimental materials to examine the roles of SA in root-shoot communication responses to aerial or/and root-zone chilling stress in own-root and hetero-root grafted cucumber and pumpkin plants. The results showed that pumpkin (Cm) rootstock enhanced the chilling tolerance of grafted cucumber, as evidenced by the observed lower levels of electrolyte leakage (EL), malondialdehyde (MDA), and higher photosynthetic rate (Pn) and gene expression of Rubisco activase (RCA). However, cucumber (Cs) rootstock decreased the chilling tolerance of grafted pumpkins. Cs/Cm plants showed an increase in the mRNA expression of C-repeat-binding factor (CBF1), an inducer of CBF expression (ICE1), and cold-responsive (COR47) genes and CBF1 protein levels in leaves under 5/25 and 5/5°C stresses, or in roots under 25/5 and 5/5°C stresses, respectively, compared with the Cs/Cs. Chilling stress increased the endogenous SA content and the activity of phenylalanine ammonia-lyase (PAL), and the increase in SA content and activity of PAL in Cs/Cm plants was much higher than in Cs/Cs plants. Transcription profiling analysis revealed the key genes of SA biosynthesis, PAL, ICS, and SABP2 were upregulated, while SAMT, the key gene of SA degradation, was downregulated in Cs/Cm leaves, compared with Cs/Cs leaves under chilling stress. The accumulation of SA in the Cs/Cm leaves was mainly attributed to an increase in SA biosynthesis in leaves and that in transport from roots under aerial and root-zone chilling stress, respectively. In addition, exogenous SA significantly upregulated the expression level of cold-responsive (COR) genes, enhanced actual photochemical efficiency (Φ PSII), maximum photochemical efficiency (F v/F m), and Pn, while decreased EL, MDA, and CI in grafted cucumber. These results suggest that SA is involved in rootstock-scion communication and grafting-induced chilling tolerance by upregulating the expression of COR genes in cucumber plants under chilling stress.

Crystal Orientation Modulation and Defect Passivation for Efficient and Stable Methylammonium-Free Dion-Jacobson Quasi-2D Perovskite Solar Cells.

Dion-Jacobson (DJ) quasi-2D perovskite solar cells (PSCs) have received increasing attention due to their greater potentials in realizing efficient and stable quasi-2D PSCs relative to their Ruddlesden-Popper counterpart. The substitution of methylammonium (MA+) with formamidinium is expected to be able to further increase the stability and power conversion efficiency (PCE) of DJ quasi-2D PSCs. Herein, we report a multifunctional additive strategy for preparing high-quality MA-free DJ quasi-2D perovskite films, where 1,1'-carbonyldi(1,2,4-triazole) (CDTA) molecules are incorporated into the perovskite precursor solution. CDTA modification can control phase distribution, enlarge grain size, modulate crystallinity and crystal orientation, and passivate defects. After CDTA modification, more favorable gradient phase distribution and accordingly gradient band alignment are formed, which is conducive to carrier transport and extraction. The improved crystal orientation can facilitate carrier transport and collection. The enlarged grain size and effective defect passivation contribute to reduced defect density. As a result, the CDTA-modified device delivers a PCE of 16.07%, which is one of the highest PCEs ever reported for MA-free DJ quasi-2D PSCs. The unencapsulated device with CDTA maintains 92% of its initial PCE after aging under one sun illumination for 360 h and 86% after aging at 60 °C for 360 h.

Detecting urine metabolites of bladder cancer by surface-enhanced Raman spectroscopy.

AIM: Metabolites present in urine reflect the current phenotype of the cancer state. Surface-enhanced Raman spectroscopy (SERS) can be used in urine supernatant or sediment to largely reflect the metabolic status of the body. MATERIALS & METHODS: SERS was performed to detect bladder cancer (BCa) and predict tumour grade from urine supernatant, which contains various system metabolites, as well as from urine sediment, which contains exfoliated tumour cells. RESULTS & DISCUSSION: Upon combining the urinary supernatant and sediment results, the total diagnostic sensitivity and specificity of SERS were 100% and 98.85%, respectively, for high-grade tumours and 97.53% and 90.80%, respectively, for low-grade tumours. CONCLUSION: The present results suggest high potential for SERS to detect BCa from urine, especially when combining both urinary supernatant and sediment results.

[Hydrogen sulfide acted as a downstream signal was involved in the regulation of salicylic acid on photosynthesis of cucumber seedlings under low temperature and low light intensity]. / H2S作为下游信号参与SAå¯¹ä½Žæ¸©å¼±å ‰ä¸‹é»„ç“œå¹¼è‹—å ‰åˆä½œç”¨çš„è°ƒæŽ§.

Both salicylic acid (SA) and hydrogen sulfide (H2S) play an important role in regulating plant growth and development and physiological metabolism under abiotic stresses. As signal molecules, the interaction between them in regulating cucumber photosynthesis under low temperature and low light is still unclear. Here, we examined the regulation and interaction of SA and H2S on photosynthesis in cucumber seedlings under low temperature (8 ℃/5 ℃, day/night) and low light (100 µmol·m-2·s-1). Seedlings were foliar-sprayed with SA, sodium sulfide (NaHS, H2S donor), and their scavenger or biosynthesis inhibitors, respectively. Seedlings treated with deionized water at suitable temperature and light condition were used as the control. The results showed that SA increased the L-/D-cysteine desulfhydrase (LCD, DCD) activities and relative mRNA expression, and consequently promoted the endogenous H2S production. However, NaHS did not affect the activities and gene expressions of phenylalnine ammonialyase and isochorismate and endogenous SA level. Compared with the H2O-treated seedlings under low temperature and low light, SA- and NaHS-treated seedlings showed an increase in the photosynthetic rate, stomatal conductance and transpiration rate, while a decrease in intercellular CO2 concentration. SA and NaHS increased the CO2 assimilation, which mainly attributed to the increases in the activities of the ribulose-1, 5-bisphosphate carboxylase, rubisco activase, sedoheptulose-1, 7-bisphosphatase and fructose-1, 6-bisphosphatase, as well as their mRNA expression. Meanwhile, SA and NaHS improved the actual photochemical efficiency and maximal photochemical efficiency of PSII, and therefore alleviated the damage in photosynthetic apparatus and negative effect on growth from low temperature and low light stress. The SA-induced higher photosynthesis and growth in stressed seedlings were suppressed by addition of H2S scavenger hypotaurine. However, the H2S-induced tolerance of photosynthetic apparatus to low temperature and low light was not affected by SA biosynthesis inhibitor paclobutrazol and 2-aminoindan-2-phosphonic acid. Our results suggested that H2S, as a downstream signal of SA, was involved in regulating photosynthesis in cucumber seedlings under low temperature and low light.