Formation of Supernarrow Borophene Nanoribbons.

Borophenes have sparked considerable interest owing to their fascinating physical characteristics and diverse polymorphism. However, borophene nanoribbons (BNRs) with widths less than 2 nm have not been achieved. Herein, we report the experimental realization of supernarrow BNRs. Combining scanning tunneling microscopy imaging with density functional theory modeling and ab initio molecular dynamics simulations, we demonstrate that, under the applied growth conditions, boron atoms can penetrate the outermost layer of Au(111) and form BNRs composed of a pair of zigzag (2,2) boron rows. The BNRs have a width self-contained to ∼1 nm and dipoles at the edges to keep them separated. They are embedded in the outermost Au layer and shielded on top by the evacuated Au atoms, free of the need for post-passivation. Scanning tunneling spectroscopy reveals distinct edge states, primarily attributed to the localized spin at the BNRs' zigzag edges. This work adds a new member to the boron material family and introduces a new physical feature to borophenes.

Using Fuzzy C-Means Clustering to Determine First Arrival of Microseismic Recordings.

Accurate and automatic first-arrival picking is one of the most crucial steps in microseismic monitoring. We propose a method based on fuzzy c-means clustering (FCC) to accurately divide microseismic data into useful waveform and noise sections. The microseismic recordings' polarization linearity, variance, and energy are employed as inputs for the fuzzy clustering algorithm. The FCC produces a membership degree matrix that calculates the membership degree of each feature belonging to each cluster. The data section with the higher membership degree is identified as the useful waveform section, whose first point is determined as the first arrival. The extracted polarization linearity improves the classification performance of the fuzzy clustering algorithm, thereby enhancing the accuracy of first-arrival picking. Comparison tests using synthetic data with different signal-to-noise ratios (SNRs) demonstrate that the proposed method ensures that 94.3% of the first arrivals picked have an error within 2 ms when SNR = -5 dB, surpassing the residual U-Net, Akaike information criterion, and short/long time average ratio approaches. In addition, the proposed method achieves a picking accuracy of over 95% in the real dataset tests without requiring labelled data.

I2C: Invertible Continuous Codec for High-Fidelity Variable-Rate Image Compression.

Lossy image compression is a fundamental technology in media transmission and storage. Variable-rate approaches have recently gained much attention to avoid the usage of a set of different models for compressing images at different rates. During the media sharing, multiple re-encodings with different rates would be inevitably executed. However, existing Variational Autoencoder (VAE)-based approaches would be readily corrupted in such circumstances, resulting in the occurrence of strong artifacts and the destruction of image fidelity. Based on the theoretical findings of preserving image fidelity via invertible transformation, we aim to tackle the issue of high-fidelity fine variable-rate image compression and thus propose the Invertible Continuous Codec (I2C). We implement the I2C in a mathematical invertible manner with the core Invertible Activation Transformation (IAT) module. I2C is constructed upon a single-rate Invertible Neural Network (INN) based model and the quality level (QLevel) would be fed into the IAT to generate scaling and bias tensors. Extensive experiments demonstrate that the proposed I2C method outperforms state-of-the-art variable-rate image compression methods by a large margin, especially after multiple continuous re-encodings with different rates, while having the ability to obtain a very fine variable-rate control without any performance compromise.

Paeoniflorin Alleviates Cisplatin-Induced Diminished Ovarian Reserve by Restoring the Function of Ovarian Granulosa Cells via Activating FSHR/cAMP/PKA/CREB Signaling Pathway.

Paeoniflorin (PAE) is the main active compound of Radix Paeoniae Rubra (a valuable traditional Chinese medicine and a dietary supplement) and exerts beneficial effects on female reproductive function. However, the actions of PAE on diminished ovarian reserve (DOR, a very common ovarian function disorder) are still unclear. Herein, our study investigated the effect and potential mechanism of PAE on DOR by using cisplatin-induced DOR mice and functional impairment of estradiol (E2) synthesis of ovarian granulosa-like KGN cells. Our data show that PAE improved the estrous cycle, ovarian index, and serum hormones levels, including E2, and the number of antral follicles and corpora lutea in DOR mice. Further mechanism results reveal that PAE promoted aromatase expression (the key rate-limiting enzyme for E2 synthesis) and upregulated the FSHR/cAMP/PKA/CREB signaling pathway in the ovaries. Subsequently, PAE improved the levels of E2 and aromatase and activated the FSHR/cAMP/PKA/CREB signaling pathway in KGN cells, while these improving actions were inhibited by the siRNA-FSHR and FSHR antagonist treatments. In sum, PAE restored the function of E2 synthesis in ovarian granulosa cells to improve DOR by activating the FSHR/cAMP/PKA/CREB signaling pathway, which exhibited a new clue for the development of effective therapeutic agents for the treatment of DOR.

Tailoring particle size of PbI2 towards efficient perovskite solar cells under ambient air conditions.

PbI2 films as templates are essential to the quality of perovskite (PVK) film in a two-step sequential deposition process. Herein, we demonstrate that PbI2 microcrystal powder (P-PbI2) of micrometer size is beneficial for preparing higher-quality PbI2 films in contrast to millimeter-sized PbI2 crystals (C-PbI2) under low relative humidity (RH) conditions. Surprisingly, C-PbI2 allowed the growth of denser films than P-PbI2 under heavy RH conditions. Ultimately, P-PbI2 gave PVK solar cells (PSCs) a best power conversion efficiency (PCE) of 23.30% under a low RH of 30 ± 5%, and C-PbI2 derived an impressive PCE of 21.09% when fabricated under conditions with RH = 50 ± 5%. This work provides ideas for the selection of lead iodide for the fabrication of PSCs under air conditions.

METTL16-mediated translation of CIDEA promotes non-alcoholic fatty liver disease progression via m6A-dependent manner.

Background: As the most prevalent chemical modifications on eukaryotic mRNAs, N6-methyladenosine (m6A) methylation was reported to participate in the regulation of various metabolic diseases. This study aimed to investigate the roles of m6A methylation and methyltransferase-like16 (METTL16) in non-alcoholic fatty liver disease (NAFLD). Methods: In this study, we used a model of diet-induced NAFLD, maintaining six male C57BL/6J mice on high-fat diet (HFD) to generate hepatic steatosis. The high-throughput sequencing and RNA sequencing were performed to identify the m6A methylation patterns and differentially expressed mRNAs in HFD mice livers. Furthermore, we detected the expression levels of m6A modify enzymes by qRT-PCR in liver tissues, and further investigated the potential role of METTL16 in NAFLD through constructing overexpression and a knockdown model of METTL16 in HepG2 cells. Results: In total, we confirmed 15,999 m6A recurrent peaks in HFD mice and 12,322 in the control. Genes with differentially methylated m6A peaks were significantly associated with the dysregulated glucolipid metabolism and aggravated hepatic inflammatory response. In addition, we identified five genes (CIDEA, THRSP, OSBPL3, GDF15 and LGALS1) that played important roles in NAFLD progression after analyzing the differentially expressed genes containing differentially methylated m6A peaks. Intriguingly, we found that the expression levels of METTL16 were substantially increased in the NAFLD model in vivo and in vitro, and further confirmed that METTL16 upregulated the expression level of lipogenic genes CIDEA in HepG2 cells. Conclusions: These results indicate the critical roles of m6A methylation and METTL16 in HFD-induced mice and cell NAFLD models, which broaden people's perspectives on potential m6A-related treatments and biomarkers for NAFLD.

CircPTK2 inhibits the tumorigenesis and metastasis of gastric cancer by sponging miR-134-5p and activating CELF2/PTEN signaling.

BACKGROUND: CircRNAs are a new subset of noncoding RNAs formed by covalent closed loops and play crucial roles in the regulation of cancer gene expression. However, the roles and underlying mechanisms of circRNAs in gastric cancer (GC) remain indistinct. This study aimed to explore the role and mechanism of hsa_circ_0006421 (circPTK2) in GC. METHODS: The differential expression of circRNAs between GC tissues and adjacent normal tissues were identified by a circRNA expression profiling. Associations of circPTK2 or miR-134-5p expression with clinicopathological characteristics and prognosis of GC patients were analyzed by chi-square of Fisher's exact tests and Kaplan-Meier analysis. CCK8, colony formation, EdU assays and animal models were performed to assess the effects of circPTK2 on proliferation and invasion of GC cells. CircPTK2-specific probes were used to purify the RNA pulled down from the circPTK2, and enrichment of circPTK2 and miR-134-5p was detected by qRT-PCR. The effects of circPTK2 on miR-134-5p expression and CELF2/PTEN signaling were examined by qRT-PCR and Western blotting analysis. RESULTS: Low expression of circPTK2 and high expression of miR-134-5p were related to the poor survival, and high expression of miR-134-5p was related to the tumor recurrence in GC patients. Overexpressing circPTK2 suppressed the proliferation, colony formation, DNA synthesis and cell invasion as well as xenograft tumor growth and lung metastasis in vitro and in vivo, whereas silencing circPTK2 had the opposite effects. Moreover, circPTK2 was negatively correlated and co-localized with miR-134-5p in the cytoplasm of GC tissue cells. circPTK2 bound to and sponged miR-134-5p in GC cells, and miR-134-5p facilitated cell growth and invasion but attenuated circPTK2 induced tumor suppressive effects and CELF2/PTEN signaling activation in GC cells. CONCLUSIONS: circPTK2 functions as a tumor suppressor in GC by sponging miR-134-5p and activating the CELF2/PTEN axis.

Local Cu Component Engineering to Achieve Continuous Carrier Transport for Enhanced Kesterite Solar Cells.

Although the traditional Cu-poor architecture addresses many limitations for Cu2ZnSn(S,Se)4 solar cells, its further development still encounters a bottleneck in terms of efficiency, primarily arising from the inferior charge transport within the quasineutral region and enlarged recombination at back contact. On the contrary, the electrical benign kesterite compound with higher Cu content may compensate for these shortages, but it will degrade device performance more pronouncedly at front contact because of the Fermi level pinning and more electric shunts. Based on the electric disparities on their independent side, in this work, we propose a new status of Cu component by exploring a large grain/fine grain/large grain trilayer architecture with higher Cu content near back contact and lower Cu content near front contact. The benefits of this bottom Cu-higher strategy are that it imposes a concentration gradient to drive carrier diffusion toward front contact and decreases the valence band edge offset in the rear of the device to aid in hole extraction. Also, it maintains the Cu-poor architecture at the near surface to facilitate hole quasi-Fermi level splitting. In return, the local Cu component engineering-mediated electric advances contribute to the highest efficiency of 12.54% for kesterite solar cells using amine-thiol solution systems so far.

Total Synthesis of the Proposed Microcyclamides MZ602 and MZ568.

The first convergent total synthesis for the proposed structures of microcyclamides MZ602 (1) and MZ568 (2) has been accomplished in 11 linear steps with 12.5 and 16.8% overall yield, respectively. Key features of the syntheses include a one-pot cascade reaction to construct core Boc-l-Ile-Thz-OAllyl fragment 5, and a removable pseudoproline (ΨMe,Me pro) inducer assisted cyclization of thiazole-containing all-l linear peptides. The spectral data (1H NMR, 13C NMR, and HRMS) of synthetic MZ602 (1) were quite similar to those of the proposed natural microcyclamide MZ602, except to an opposite sign of the optical rotation value. Surprisingly, the synthetic MZ568 (2) presented large discrepancies in characteristic spectral data from those of the reported natural product, although the absolute configuration of key intermediate 36 was unambiguously determined by single-crystal X-ray analysis in our work. These findings revealed that the proposed structures of natural microcyclamides MZ602 and MZ568 required revision.

A selective N,N-dithenoyl-rhodamine based fluorescent probe for Fe3+ detection in aqueous and living cells.

A novel N,N-dithenoyl-rhodamine based fluorescent and colorimetric Fe3+ probe 1 was designed and synthesized by only one step from Rhodamine B hydrazide and 2-thiophenecarbonyl chloride. The structure of probe 1 was characterized by 1H NMR/13C NMR spectroscopy, IR spectroscopy, and HRMS spectrometry. Accompanying with significant changes in visual color and fluorescent spectrum, probe 1 displayed good sensitivity for Fe3+ with an abroad pH span. The detection limit (3.76 µmol/L, 0.2 mg/L) for Fe3+ was lower than WHO recommended value (0.3 mg/L) for drinking water. Using two thiophene carbonyl groups as coordinating functional recognition group, probe 1 showed excellent selectivity towards Fe3+ over diverse coexistent metal ions and anions. The sensing mechanism between dithenoyl-substituted probe 1 and Fe3+ was further confirmed by 1H NMR and IR titration experiments, binding constants study, and Job's plot analysis. Furthermore, probe 1 also exhibited good cell membrane permeability and could be used as an efficient Fe3+ probe in living human cells.

Selective Enrichment of Clenbuterol onto Molecularly Imprinted Polymer Microspheres with Tailor-made Structure and Oxygen Functionalities.

The noxious clenbuterol misapplied as the feed additive has posed an enormous threat to humans who actively rely on the food chains with high potential of contamination by clenbuterol, such as pork and beef. It is, therefore, highly desirable to develop novel materials and strategies for dealing with the clenbuterol. Herein, functional polymer microspheres prepared by Pickering emulsion polymerization were explored for the selective enrichment of the clenbuterol, and their structure and oxygen functionalities could be tailor-made by a molecular imprinting process. The clenbuterol imprinting was adequately demonstrated to not only increase the particle size (~52 nm vs. ~42 nm) and create cavities for the accommodation of the clenbuterol molecules, but also reduce the oxygen functionalities of the resulting molecularly imprinted polymer microspheres (MIPMs) by approximately 4 at.%, which is believed to correlate with the high specificity of the MIPMs. Various characterization methods were employed to evidence these findings, including scanning electron microscopy, BET measurements, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and elemental mapping examination. More importantly, the MIPMs showed a markedly superior enrichment capability towards clenbuterol to the counterpart, that is, non-molecularly imprinted polymer microspheres (NIPMs). Compared to the NIPMs without specificity for clenbuterol, the MIPMs exhibited an impressive selectivity to clenbuterol, with the relative selectivity coefficient (k') values largely exceeding 1, thus corroborating that the useful molecular imprinting led to the generation of the binding sites complementary to the clenbuterol molecule in the size and functionalities. The MIPMs were also employed as the stationary phase to fabricate molecularly imprinting solid-phase extraction column, and the spike recovery was demonstrated to be not significantly decreased even after nine cycles. Furthermore, the reliability of the method was also evidenced through the comparison of the MIPMs prepared from different batches.

Adsorption Features of Formaldehyde on TiO2(110) Surface Probed by High-Resolution Scanning Tunnelling Microscopy.

We report a real-space imaging of formaldehyde (HCHO) adsorption on a TiO2(110) surface probed by high-resolution scanning tunnelling microscopy (STM). Density functional theory calculations (DFT) were carried out to assign the observed features. The adsorptions occur exclusively on 5-fold coordinated Ti (Ti5c) sites and oxygen vacancies (OVs). The well-resolved configurations on the Ti5c sites feature the overlapping of the two "dumbbell" structures which are originated from the empty orbitals of HCHO. The STM images for the physical adsorption of HCHO on the OV sites appear fuzzy because of the rapid switching of HCHO among the three stable orientations, while those for the chemical adsorption are much clearer, revealing a distinctive difference between chemical and physical adsorptions. This work presents a systematic characterization of the topological features of HCHO/TiO2(110) and provides useful information for mechanical understanding of the reaction mechanism of HCHO on the surfaces.

CCR7 regulates ANO6 to promote migration of pancreatic ductal adenocarcinoma cells via the ERK signaling pathway.

The increase in migratory ability of pancreatic ductal adenocarcinoma cells is a key event in the development of metastasis to the lymph nodes and distant organs. Although the C-C motif chemokine receptor 7 (CCR7) and its ligand, C-C motif chemokine ligand 21 (CCL21), have been revealed to serve an important role in tumor migration, their precise roles and potential underlying mechanisms remain largely unknown. The present study revealed that overexpression of CCR7 significantly promoted BxPC-3 cell migration, accompanied by the induction of anoctamin 6 (ANO6) expression, indicating that ANO6 is a downstream target of CCR7 signaling. Furthermore, the level of phosphorylated extracellular signal-regulated kinase (ERK) was significantly increased in CCR7-overexpressing BxPC-3 cells, indicating that ERK may be a potential mediator of CCR7-regulated ANO6 expression in BxPC-3 cells. To characterize the receptor-mediated pathway, a specific ERK inhibitor, U0126, was used, which reduced BxPC-3 cell migration and the expression of ANO6. In summary, the results of the present study demonstrate that CCR7 promoted BxPC-3 cell migration by regulating ANO6 expression perhaps via activation of the ERK signaling pathway.

Early prediction of persistent organ failure by serum apolipoprotein A-I and high-density lipoprotein cholesterol in patients with acute pancreatitis.

BACKGROUND: Early identification of acute pancreatitis (AP) patients at high-risk of developing persistent organ failure (persistent OF) is a vital clinical goal. This research intends to assess the ability of apolipoprotein A-I (APO A-I) and high-density lipoprotein cholesterol (HDL-C) to predict persistent OF. METHODS: Between January 2011 and September 2016, a total of 102 adult AP patients with organ failure, local complications or deterioration of former comorbidities disease during hospitalization were included in this study retrospectively. Serum lipids were tested and computed the correlation with clinical outcomes or scoring systems. The AUCs to predict persistent OF were also calculated and compared with each other. RESULTS: Serum APO A-I and HDL-C levels were negatively associated with scoring systems. Meanwhile, serum lipids were negatively correlated with poor clinical outcomes. The AUCs of APO A-I, HDL-C, the combination of APO A-I and BISAP, or the combination of APO A-I and MCTSI to predict persistent OF among Moderately severe acute pancreatitis (MSAP) and Severe acute pancreatitis (SAP) patients were 0.886, 0.811, 0.912, and 0.900 or among those with organ failure were 0.915, 0.859, 0.933, and 0.933, respectively. CONCLUSIONS: The concentrations of APO A-I, HDL-C, and the combinations of APO A-I and scoring systems have high predictive value to predict persistent OF.

Endogenous hydrogen sulfide is associated with angiotensin II type 1 receptor in a rat model of carbon tetrachloride-induced hepatic fibrosis.

The present study aimed to investigate the effects of endogenous hydrogen sulfide (H2S) on the expression levels of angiotensin II type 1 receptor (AGTR1) in a rat model of carbon tetrachloride (CCl4)­induced hepatic fibrosis. A total of 56 Wistar rats were randomly divided into four groups: Normal control group, model group, sodium hydrosulfide (NaHS) group, and DL­propargylglycine (PAG) group. Hepatic fibrosis was induced by CCl4. The rats in the PAG group were intraperitoneally injected with PAG, an inhibitor of cystathionine­Î³­lyase (CSE). The rats in the NaHS group were intraperitoneally injected with NaHS. An equal volume of saline solution was intraperitoneally injected into both the control and model groups. All rats were sacrificed at week three or four following treatment. The serum levels of hyaluronidase (HA), laminin protein (LN), procollagen III (PcIII), and collagen IV (cIV) were detected using ELISA. The serum levels of alanine transaminase (ALT), aspartate transaminase (AST), and albumin (ALB) were detected using an automatic biochemical analyzer. The liver mRNA expression levels of CSE were detected by reverse transcription­quantitative polymerase chain reaction. The liver expression levels of AGTR1 and the plasma expression levels of H2S were detected using western blot analyses. The results indicated that the severity of hepatic fibrosis, the serum expression levels of HA, LN, PcIII, cIV, ALT, and AST, the liver expression levels of CSE and AGTR1, and the plasma expression levels of H2S were significantly higher in the PAG group, as compared with the model group (P<0.05). Conversely, the expression levels of ALB were significantly lower in the PAG group, as compared with the model group. In addition, the severity of hepatic fibrosis, the serum expression levels of HA, LN, PcIII, cIV, ALT, and AST, the liver expression levels of CSE and AGTR1, and the plasma expression levels of H2S were significantly lower in the NaHS group, as compared with the model group (P<0.05). These results suggest that endogenous H2S is associated with CCl4­induced hepatic fibrosis in rats, and may exhibit anti­fibrotic effects. Furthermore, H2S reduced the liver expression levels of AGTR1, which may be associated with the delayed progression of hepatic fibrosis.

Synthesis of quinolinones with palladium-catalyzed oxidative annulation between acrylamides and arynes.

An unprecedented palladium-catalyzed oxidative annulation of acrylamides with benzyne precursors has been successfully developed. By using this mild "N-H activation/Heck reaction" method, a wide variety of quinolinones were conveniently prepared in one step with high efficiency.

Mullite-supported Rh catalyst: a promising catalyst for the decomposition of N2O propellant.

A mullite-supported Rh catalyst with an unusual crystalline structure in favour of high-temperature reactions was applied for the first time to the catalytic decomposition of N(2)O propellants, and has shown a promising initial activity and thermal stability.

Isolation and functional analysis of LiYAB1, a YABBY family gene, from lily (Lilium longiflorum).

YABBY family proteins are plant-specific transcriptional factors. YABBY genes can be divided into three subfamilies. Within the CRC/DL subfamily, the Arabidopsis CRC (CRABS CLAW) and the rice DL (DROOPING LEAF) have functionally diverged in the control of leaf development. CRC has no function in leaf development, while DL plays an important role in the formation of leaf midribs. In this study LiYAB1, an ortholog of CRC/DL genes from lily (Lilium longiflorum), was isolated by screening a cDNA library derived from young lily flower buds. Subcellular localization analysis indicated that LiYAB1 is nuclear localized. LiYAB1 is expressed strongly in the carpels of the lily flower and weakly in the leaves, which is similar to DL in rice. Ectopic expression of LiYAB1 in the rice dl mutant could rescue the drooping leaf phenotype of dl in some of the transgenic rice plants and cause abnormal leaves in the other transgenic plants. The overexpression of LiYAB1 in the wild-type Arabidopsis caused leaf abnormality. The results suggest that LiYAB1, a member of the CRC/DL subfamily genes, might have an important function in regulating the leaf development in lilies, as DL does in rice.