Non-Noble-Metal-Based Electrocatalysts for Acidic Oxygen Evolution Reaction: Recent Progress, Challenges, and Perspectives.

The oxygen evolution reaction (OER) plays a pivotal role in diverse renewable energy storage and conversion technologies, including water electrolysis, electrochemical CO2 reduction, nitrogen fixation, and metal-air batteries. Among various water electrolysis techniques, proton exchange membrane (PEM)-based water electrolysis devices offer numerous advantages, including high current densities, exceptional chemical stability, excellent proton conductivity, and high-purity H2. Nevertheless, the prohibitive cost associated with Ir/Ru-based OER electrocatalysts poses a significant barrier to the broad-scale application of PEM-based water splitting. Consequently, it is crucial to advance the development of non-noble metal OER catalysis substance with high acid-activity and stability, thereby fostering their widespread integration into PEM water electrolyzers (PEMWEs). In this review, a comprehensive analysis of the acidic OER mechanism, encompassing the adsorbate evolution mechanism (AEM), lattice oxygen mechanism (LOM) and oxide path mechanism (OPM) is offered. Subsequently, a systematic summary of recently reported noble-metal-free catalysts including transition metal-based, carbon-based and other types of catalysts is provided. Additionally, a comprehensive compilation of in situ/operando characterization techniques is provided, serving as invaluable tools for furnishing experimental evidence to comprehend the catalytic mechanism. Finally, the present challenges and future research directions concerning precious-metal-free acidic OER are comprehensively summarized and discussed in this review.

Diversity-Oriented Synthesis of Indole-Fused Polycyclic Scaffolds via Rhodium-Catalyzed NH-Indole-Directed C-H Coupling of 2-Phenyl-1H-indoles with Propargylic Alcohol Derivatives.

Diversity-oriented synthesis strategy for the efficient assembly of indole-fused polycyclic scaffolds via rhodium-catalyzed NH-indole-directed C-H coupling with propargylic alcohol derivatives in a regioselective manner was developed. Five 2-phenyl-1H-indole-embedded core skeletons were synthesized. In particular, three different indole-fused exo-olefin-containing polycycles were realized, which may be manipulated for further chemistry.

Cascade Electrochemical Aerobic Oxygenation of 2-Substituted Indoles and Electrochemical [5 + 3] Annulation with Amidines: Access to Eight-Membered Benzo[1,3,5]triazocin-6(5H)-ones.

The cascade electrochemical C3-selective aerobic oxygenation of 2-substituted indoles and electrochemical [5 + 3] annulation with amidines through an undivided cell galvanostatic method employing molecular oxygen and "electricity" as green oxidants was developed. This protocol provides an efficient and direct approach to eight-membered benzo[1,3,5]triazocin-6(5H)-ones. Mechanistic studies suggested that two subsequent electrochemical processes both proceeded through radical pathways.

Blue-Light Driven Iron-Catalyzed Oxy-phosphinylation of Activated Alkenes for ß-Ketophosphine Oxide Synthesis.

We have developed an original blue-light mediated iron-catalyzed oxy-phosphinylation of activated alkenes by secondary phosphine oxides under air at room temperature. Various ß-ketophosphine oxides were then obtained in 43-97 % isolated yields. Control experiments revealed that radical process is involved in the mechanism.

Rhodaelectro-Catalyzed Decarboxylative Cross-Dehydrogenative Coupling of Indole-3-carboxylic Acids and Olefins via Weakly Coordinating Carboxyl Groups.

A rhodaelectro-catalyzed C2-H selectively decarboxylative alkenylation of 3-carboxy-1H-indoles employing electricity as the traceless terminal oxidant has been accomplished. The weakly coordinating carboxyl group serves as the traceless directing groups. External oxidant-free in an undivided cell with constant current in aqueous solution ensures the decarboxylative C-H alkenylation to be viable and sustainable.

Aplasia Cutis Congenita With Cutaneous Meningioma: A Rare Case.

ABSTRACT: Cutaneous meningioma, characterized by ectopic meningothelial cells in the dermis or subcutis, is a rare neoplasm. Generally, the most common location for cutaneous meningioma is the scalp. We report a case of cutaneous meningioma presenting as soft, light red, atrophic, and smooth patches with central blue spots. On histological examination, the tumor consisted largely of epithelioid cells, whorls, nests, and syncytial sheets of meningothelial cells. HMB-45, Melan-A, and S100 were negative; epithelial membrane antigen and somatostatin receptor 2 were positive. Ultimately, histopathologic examination and immunohistochemistry results supported a diagnosis of cutaneous meningioma. In addition, dermal dysplasia was observed above the tumor, manifested by thinning of the dermis and loss of appendages. No abnormalities were found on brain magnetic resonance imaging. Cutaneous meningioma is an extremely rare tumor, and its manifestation as an atrophic patch is even rarer. There have been mainly clinical reports of cutaneous meningioma. This was a rare case of focal aplasia cutis congenita with cutaneous meningioma. For cutaneous meningioma to be diagnosed earlier, there needs to be greater public awareness about the condition.

Bowl-Assisted Ball Assembly for Solvent-Processing the C60 Electron Transport Layer of High-Performance Inverted Perovskite Solar Cell.

Pristine fullerene C60 is an excellent electron transport material for state-of-the-art inverted structure perovskite solar cells (PSCs), but its low solubility leaves thermal evaporation as the only method for depositing it into a high-quality electron transport layer (ETL). To address this problem, we herein introduce a highly soluble bowl-shaped additive, corannulene, to assist in C60 -assembly into a smooth and compact film through the favorable bowl-ball interaction. Our results show that not only corannulene can dramatically enhance the film formability of C60 , it also plays a critical role in forming C60 -corannulene (CC) supramolecular species and in boosting intermolecular electron transport dynamics in the ETL. This strategy has allowed CC devices to deliver high power conversion efficiencies up to 21.69 %, which is the highest value among the PSCs based on the solution-processed-C60 (SP-C60 ) ETL. Moreover, the stability of the CC device is far superior to that of the C60 -only device because corannulene can retard and curb the spontaneous aggregation of C60 . This work establishes the bowl-assisted ball assembly strategy for developing low-cost and efficient SP-C60 ETLs with high promise for fully-SP PSCs.

Chemodivergent Synthesis of Indeno[1,2-b]indoles and Isoindolo[2,1-a]indoles via Mn(III)-Mediated or Electrochemical Intramolecular Radical Cross-Dehydrogenative Coupling.

Chemodivergent synthesis of indeno[1,2-b]indoles and isoindolo[2,1-a]indoles from the same starting materials involving radical cross-dehydrogenative couplings have been developed. Mn(OAc)3·2H2O selectively promoted an intramolecular radical C-H/C-H dehydrogenative coupling reaction to provide indeno[1,2-b]indoles, while an intramolecular radical C-H/N-H dehydrogenative coupling reaction could proceed via electrochemistry to deliver isoindolo[2,1-a]indoles. Plausible mechanisms of the chemodivergent reactions were proposed.

Synthesis of Indole-Fused Six-, Seven-, or Eight-Membered N,O-Heterocycles via Rhodium-Catalyzed NH-Indole-Directed C-H Acetoxylation/Hydrolysis/Annulation.

We report herein the facile synthesis of indole-fused six-, seven-, or eight-membered N,O-heterocycles through rhodium-catalyzed C-H acetoxylation/hydrolysis/annulation. The notable features of this method include C-H acetoxylation using NH-indole as the intrinsic directing group, high functional group compatibility, and construction of indole-fused medium-sized rings.

Rhodium-Catalyzed Oxidative Annulation of 2- or 7-Arylindoles with Alkenes/Alkynes Using Molecular Oxygen as the Sole Oxidant Enabled by Quaternary Ammonium Salt.

Developing an efficient catalytic system using molecular oxygen as the oxidant for rhodium-catalyzed cross-dehydrogenative coupling remains highly desirable. Herein, rhodium-catalyzed oxidative annulation of 2- or 7-phenyl-1H-indoles with alkenes or alkynes to assemble valuable 6H-isoindolo[2,1-a]indoles, pyrrolo[3,2,1-de]phenanthridines, or indolo[2,1-a]isoquinolines using the atmospheric pressure of air as the sole oxidant enabled by quaternary ammonium salt has been accomplished. Mechanistic studies provided evidence for the fast intramolecular aza-Michael reaction and aerobic reoxidation of Rh(I)/Rh(III), facilitated by the addition of quaternary ammonium salt.

Synthesis of Seven-Membered Azepino[3,2,1-hi]indoles via Rhodium-Catalyzed Regioselective C-H Activation/1,8-Diazabicyclo[5.4.0]undec-7-ene-Catalyzed Intramolecular Amidation of 7-Phenylindoles in One Pot.

An unprecedented rhodium-catalyzed regioselective C-H activation/1,8-diazabicyclo[5.4.0]undec-7-ene-catalyzed intramolecular amidation of 7-arylindoles with diazomalonates is described that provides a straightforward route to seven-membered azepino[3,2,1-hi]indoles in good to excellent yields in one pot. A wide range of functional groups, including F, OMe, NPh2, SiMe3, Cl, CN, CHO, COMe, CO2Me, CF3, and NO2, were all well-tolerated.

Identification of drought-responsive microRNAs in tomato using high-throughput sequencing.

Drought is a major abiotic stress affecting crop productivity and quality. As a class of noncoding RNA, microRNA (miRNA) plays important roles in plant growth, development, and stress response. However, their response and roles in tomato drought stress is largely unknown. Here, by using high-throughput sequencing, we compared the miRNA profiles before and after drought treatment in two tomato genotypes: M82, a drought-sensitive cultivated tomato (Solanum lycopersicum), and IL2-5, a drought-tolerant introgression line derived from M82 and the tomato wild species S. pennellii (LA0716). A total of 108 conserved and 208 novel miRNAs were identified, among them, 32 and 68 were significantly changed in expression after stress. Further, 1936 putative target genes were predicted for those differentially-expressed miRNAs. Gene ontology and pathway analysis showed that many of the target genes were involved in stress resistance, such as genes in GO terms including response to stress, defense response, response to stimulus, phosphorylation, and signal transduction. Our results suggested that miRNAs play an essential role in the drought response of tomato. This work will help to further characterize specific miRNAs functioning in drought tolerance.

Profiling of drought-responsive microRNA and mRNA in tomato using high-throughput sequencing.

BACKGROUND: Abiotic stresses cause severe loss of crop production. Among them, drought is one of the most frequent environmental stresses, which limits crop growth, development and productivity. Plant drought tolerance is fine-tuned by a complex gene regulatory network. Understanding the molecular regulation of this polygenic trait is crucial for the eventual success to improve plant yield and quality. Recent studies have demonstrated that microRNAs play critical roles in plant drought tolerance. However, little is known about the microRNA in drought response of the model plant tomato. Here, we described the profiling of drought-responsive microRNA and mRNA in tomato using high-throughput next-generation sequencing. RESULTS: Drought stress was applied on the seedlings of M82, a drought-sensitive cultivated tomato genotype, and IL9-1, a drought-tolerant introgression line derived from the stress-resistant wild species Solanum pennellii LA0716 and M82. Under drought, IL9-1 performed superior than M82 regarding survival rate, H2O2 elimination and leaf turgor maintenance. A total of four small RNA and eight mRNA libraries were constructed and sequenced using Illumina sequencing technology. 105 conserved and 179 novel microRNAs were identified, among them, 54 and 98 were differentially expressed upon drought stress, respectively. The majority of the differentially-expressed conserved microRNAs was up-regulated in IL9-1 whereas down-regulated in M82. Under drought stress, 2714 and 1161 genes were found to be differentially expressed in M82 and IL9-1, respectively, and many of their homologues are involved in plant stress, such as genes encoding transcription factor and protein kinase. Various pathways involved in abiotic stress were revealed by Gene Ontology and pathway analysis. The mRNA sequencing results indicated that most of the target genes were regulated by their corresponding microRNAs, which suggested that microRNAs may play essential roles in the drought tolerance of tomato. CONCLUSION: In this study, numerous microRNAs and mRNAs involved in the drought response of tomato were identified using high-throughput sequencing, which will provide new insights into the complex regulatory network of plant adaption to drought stress. This work will also help to exploit new players functioning in plant drought-stress tolerance.

Palladium-catalyzed C-H olefination of uracils and caffeines using molecular oxygen as the sole oxidant.

The palladium-catalyzed oxidative C-H olefination of uracils or caffeines with alkenes using an atmospheric pressure of molecular oxygen as the sole oxidant has been disclosed. This novel strategy offers an efficient and environmentally friendly method to biologically important C5-alkene uracil derivatives or C8-alkene caffeine derivatives.

Rhodium-Catalyzed NH-Indole-Directed C-H Carbonylation with Carbon Monoxide: Synthesis of 6H-Isoindolo[2,1-a]indol-6-ones.

An efficient synthesis of 6H-isoindolo[2,1-a]indol-6-ones through rhodium-catalyzed NH-indole-directed C-H carbonylation of 2-arylindoles with carbon monoxide has been developed. Preliminary mechanistic studies revealed that this reaction proceeds via N-H bond cleavage and subsequent C-H bond cleavage. Reaction monitoring via ESI-MS was used to support the formation of five-membered rhodacycle species in the catalytic cycle.

Diode-pumped tape casting planar waveguide YAG/Nd:YAG/YAG ceramic laser.

We demonstrated the efficient guided laser action in a diode-pumped YAG/Nd:YAG/YAG ceramic planar waveguide produced by tape casting and vacuum sintering technology for the first time to the best of our knowledge. In the regime of continuous wave operation, a maximum output power of 840 mW corresponding to the slope efficiency of 65% was achieved. During passively Q-switched operation, by replacing the dichroic mirror with graphene-oxide based output coupler, we obtained the stable pulse trains with the shortest pulse duration of 179 ns at a pulse repetition rate of 930 kHz which resulted in the single pulse energy of 221 nJ.

Discovery of Loureirin analogues with colorectal cancer suppressive activity via regulating cell cycle and Fas death receptor.

Chalcones and dihydrochalcones (DHCs) are important bioactive natural products (BNPs) isolated from traditional Chinese medicine. In this study, 13 chalcones were designed with the inspiration of Loureirin, a DHC extracted from Resina Draconis, and synthesized by classical Claisen-Schmidt reactions. Afterwards the reduction reactions were carried out to obtain the corresponding DHCs. Cytotoxicity assay indicated chalcones and DHCs possessed selective cytotoxicity against colorectal cancer (CRC) cells. The preliminary structure-activity relationships (SAR) of these compounds suggested the α, ß-unsaturated ketone of the chalcones were crucial for the anticancer activity. Interestingly, compounds 3d and 4c exhibited selective anticancer activity against CRC cell line HCT116 with IC50s of 8.4 and 17.9 µM but not normal cell. Moreover, 4c could also inhibit the migration and invasion of CRC cells. Mechanism investigations showed 4c could induce cell cycle G2/M arrest by regulating cell cycle-associated proteins and could also up-regulate Fas cell surface death receptor. The virtual docking further pointed out that compounds 3d and 4c could nicely bind to the Fas/FADD death domain complex (ID: 3EZQ). Furthermore, silencing of Fas significantly enhanced the proliferation of CRC cells and attenuated the cytotoxicity induced by 4c. These results suggested 4c exerted its anticancer activity possibly regulating cell cycle and Fas death receptor. In summary, this study investigated the anticancer activity and mechanism of Loureirin analogues in CRC, suggesting these compounds may warrant further investigation as promising anticancer drug candidates for the treatment of CRC.

Primary versus secondary cutaneous endometriosis: Literature review and case study.

Cutaneous endometriosis, characterized by the presence of endometrium or endometrial-like tissue outside of the uterine cavity, is an uncommon and chronic disease. Depending on a patient's history, cutaneous endometriosis is classified as either primary cutaneous endometriosis (PCE) or secondary cutaneous endometriosis (SCE). We report a case of SCE presenting with the classic triad of previous caesarean section, subcutaneous nodules at the site of the scar, and pain associated with menstruation. Considering histopathology as the standard, we confirmed a diagnosis of cutaneous endometriosis by ultrasound and histopathology. Furthermore, we compared and analyzed the clinical characteristics of PCE and SCE, the study included 20 and 14 patients with cutaneous endometriosis diagnosed with PCE and SCE respectively. In the PCE group, the mean age of patients at the onset was 33.7 years, while it was 40.6 years in the SCE group. The mean disease-duration time of PCE was shorter than that of SCE (1.3 vs. 2.8 years, P > 0.05). The most common clinical presentation of PCE and SCE was a nodule (90% vs. 86%). The PCE was mainly bleeding with pain (45%), whereas the SCE of only pain and bleeding with pain accounted for the same proportion (45%). The most common sites of PCE and SCE were in the umbilical region (90% vs. 57%, P < 0.05). In our study, some statistically significant difference was found between different types of CE and it may contribute to improve clinicians' understanding of the disease, and perform early diagnosis and treatment.