Azobenzene-based colorimetric and fluorometric chemosensor for nitroxyl releasing.

The precise release and characterization of nitroxyl (HNO) gas signaling molecule remain a challenge due to its short lifetime to date. To solve this issue, an azobenzene-based HNO donor (Azo-D1) was proposed as a colorimetric and fluorometric chemosensor for HNO releasing, to release both HNO and an azobenzene fluorescent reporter together. Specifically, the Azo-D1 has an HNO release half-life of ∼68 min under physiological conditions. The characteristic color change from the original orange to the yellow color indicated the decomposition of the donor molecule. In addition, the stoichiometry release of HNO was qualitatively and quantitatively verified through the classical phosphine compound trap. As compared with the donor molecule by itself, the decomposed product demonstrates a maximum fluorescence emission at 424 nm, where the increase of fluorescence intensity by 6.8 times can be applied to infer the real-time concentration of HNO. Moreover, cellular imaging can also be achieved using this Azo-D1 HNO donor through photoexcitation at 405 and 488 nm, where the real-time monitoring of HNO release was achieved without consuming the HNO source. Finally, the Azo-D1 HNO donor would open a new platform in the exploration of the biochemistry and the biology of HNO.

Tissue damage, antioxidant capacity, transcriptional and metabolic regulation of red drum Sciaenops ocellatus in response to nanoplastics exposure and subsequent recovery.

Nanoplastics are recognized as emerging contaminants that can cause severe toxicity to marine fishes. However, limited researches were focusing on the toxic effects of nanoplastics on marine fish, especially the post-exposure resilience. In this study, red drum (Sciaenops ocellatus) were exposed to 5 mg/L polystyrene nanoplastics (100 nm, PS-NPs) for a 7-day exposure experiment, and a 14-day recovery experiment that followed. The aim was to evaluate the dynamic alterations in hepatic and branchial tissue damage, hepatic antioxidant capacity, as well as hepatic transcriptional and metabolic regulation in the red drum during exposure and post-exposure to PS-NPs. Histopathological observation found that PS-NPs primarily triggered hepatic lipid droplets and branchial epithelial liftings, a phenomenon persistently discernible up to the 14 days of recovery. Although antioxidant capacity partially recovered during recovery periods, PS-NPs resulted in a sustained reduction in hepatic antioxidant activity, causing oxidative damage throughout the entire exposure and recovery phases, as evidenced by decreased total superoxide dismutase activities and increased malondialdehyde content. At the transcriptional and metabolic level, PS-NPs primarily induced lipid metabolism disorders, DNA damage, biofilm disruption, and mitochondrial dysfunction. In the gene-metabolite correlation interaction network, numerous CcO (cytochrome c oxidase) family genes and lipid metabolites were identified as key regulatory genes and metabolites in detoxification processes. Among them, the red drum possesses one additional CcO6B in comparison to human and zebrafish, which potentially contributes to its enhanced capacity for maintaining a stable and positive regulatory function in detoxification. This study revealed that nanoplastics cause severe biotoxicity to red drum, which may be detrimental to the survival of wild populations and affect the economics of farmed populations.

PF127/bleomycin hydrogel promotes subcutaneous extracellular matrix remodeling and fibrosis to construct personalized flaps through the TGFß-Col signaling pathway.

BACKGROUND: Skin flap transplantation is used to effectively reconstruct defects of the hand and foot skin and soft tissues. We here investigated the effect of the PF127/bleomycin (BLM) hydrogel on the extracellular matrix (ECM) remodeling of skin flaps and the underlying mechanism, thereby providing a new reference point for personalized flap modification and overcoming abrasion resistance- and stability-associated difficulties. METHODS: The appropriate PF127/BLM concentration was selected based on the gelation time and drug release curve. Migration assays, scratch assays, and live/dead staining were conducted to verify the effect of PF127/BLM on human skin fibroblasts (HSFs). The effects of PF127/BLM on the ECM were assessed through hematoxylin and eosin and Masson staining. Additionally, we examined the expression of ECM remodeling-related genes and proteins involved in their associated signaling pathway. Finally, the effects of PF127/BLM on organ fibrosis and toxicity to liver and kidney functions were assessed in mice. RESULTS: A 25% PF127/BLM hydrogel was selected as the study concentration. PF127/BLM augmented HSF chemotaxis and proliferation. Furthermore, PF127/BLM promoted subcutaneous ECM remodeling and fibrosis, increased the flap dermis thickness, and reduced the toxic side effects of BLM on liver/lung fibrosis and liver/kidney function. Additional studies confirmed that the PF127/BLM-mediated regulation of ECM remodeling in skin flaps was associated with TGFß-Col signaling pathway activation. CONCLUSION: The PF127/BLM hydrogel promoted subcutaneous ECM remodeling and fibrosis, which aided the construction of personalized flaps through the TGFß-Col signaling pathway, with decreased hepatic, pulmonary, and renal toxicities.

Real-world practice of conversion surgery for unresectable hepatocellular carcinoma - a single center data of 26 consecutive patients.

AIM: To understand the proportion of uHCC (unresectable hepatocellular carcinoma) patients who achieve successful conversion resection in a high-volume setting with state of the art treatment options. METHODS: We retrospectively reviewed all HCC patients hospitalized to our center from June 1st, 2019 to June 1st, 2022. Conversion rate, clinicopathological features, response to systemic and/or loco-regional therapy and surgical outcomes were analyzed. RESULTS: A total of 1,904 HCC patients were identified, with 1672 patients receiving anti-HCC treatment. 328 patients were considered up-front resectable. Of the remaining 1344 uHCC patients, 311 received loco-regional treatment, 224 received systemic treatment, and the remainder (809) received combination systemic plus loco-regional treatment. Following treatment, one patient from the systemic group and 25 patients from the combination group were considered to have resectable disease. A high objective response rate (ORR) was observed in these converted patients (42.3% under RECIST v1.1 and 76.9% under mRECIST criteria). The disease control rate (DCR) reached 100%. 23 patients underwent curative hepatectomy. Major post-operative morbidity was equivalent in the both groups (P=0.76). Pathologic complete response (pCR) was 39.1%. During conversion treatment, grade 3 or higher treatment-related adverse events (TRAEs) were observed in 50% of patients. The median follow-up time was 12.9 months (range, 3.9~40.6) from index diagnosis and 11.4 months (range, 0.9~26.9) from resection. Three patients experienced disease recurrence following conversion surgery. CONCLUSIONS: By intensive treatment, a small sub-group of uHCC patients (2%) may potentially be converted to curative resection. Loco-regional combined with systemic modality was relative safe and effective in the conversion therapy. Short-term outcomes are encouraging, but long-term follow-up in a larger patient population are required to fully understand the utility of this approach.

Synthesis and nitroxyl (HNO) donating properties of benzoxadiazole-based Piloty's acids.

Developing functional nitroxyl (HNO) donors play a significant role in the further exploration of endogenous HNO in biochemistry and pharmacology. In this work, two novel Piloty's acids (SBD-D1 and SBD-D2) were proposed by incorporating benzoxadiazole-based fluorophores, in order to achieve the dual-function of releasing both HNO and a fluorophore in situ. Under physiological conditions, both SBD-D1 and SBD-D2 efficiently donated HNO (t1/2 = 10.96 and 8.18 min, respectively). The stoichiometric generation of HNO was determined by both Vitamin B12 and phosphine compound trap. Interestingly, due to the different substitution groups on the aromatic ring, SBD-D1 with the chlorine showed no fluorescence emission, but SBD-D2 was strongly fluorescent due to the presence of the dimethylamine group. Specifically, the fluorescent signal would decrease during the release process of HNO. Moreover, theoretical calculations were performed to understand the emission difference. A strong radiation derived from benzoxadiazole with dimethylamine group due to the large transition dipole moment (∼4.3 Debye), while the presence of intramolecular charge transfer process in the donor with chlorine group caused a small transition dipole moment (<0.1 Debye). Finally, these studies would contribute to the future design and application of novel functional HNO donors for the exploration of HNO biochemistry and pharmacology.

Mechanisms of polydatin against spinal cord ischemia-reperfusion injury based on network pharmacology, molecular docking and molecular dynamics simulation.

BACKGROUND: Polydatin has shown considerable pharmacological activities in ischemia-reperfusion injuries of various organs. However, its effects and mechanisms in spinal cord ischemia-reperfusion injury have not been fully established. In this study, the mechanisms of polydatin against spinal cord ischemia-reperfusion injury were investigated via network pharmacology, molecular docking and molecular dynamics simulation. METHODS: Spinal cord ischemia-reperfusion injury-related targets were obtained from the GeneCards database, while polydatin-related action targets were obtained from the CTD and SwissTarget databases. A protein-protein interaction network of potential targets was constructed using the String platform. After selecting the potential key targets, GO functional enrichment and KEGG pathway enrichment analyses were performed via the Metascape database, and a network map of "drug-target-pathway-disease" constructed. The relationships between polydatin and various key targets were assessed via molecular docking. Molecular dynamics simulation was conducted for optimal core protein-compound complexes obtained by molecular docking. RESULTS: Topological analysis of the PPI network revealed 14 core targets. GO functional enrichment analysis revealed that 435 biological processes, 12 cell components and 29 molecular functions were enriched while KEGG pathway enrichment analysis revealed 91 enriched signaling pathways. Molecular docking showed that polydatin had the highest binding affinity for MAPK3, suggesting that MAPK3 is a key target of polydatin against spinal cord ischemia-reperfusion injury. Molecular dynamics simulations revealed good binding abilities between polydatin and MAPK3. CONCLUSIONS: Polydatin exerts its effects on spinal cord ischemia-reperfusion injury through multiple targets and pathways. MAPK3 may be a key target of polydatin in spinal cord ischemia-reperfusion injury.

Protective effects of polydatin against bone and joint disorders: the in vitro and in vivo evidence so far.

Polydatin is an active polyphenol displaying multifaceted benefits. Recently, growing studies have noticed its potential therapeutic effects on bone and joint disorders (BJDs). Therefore, this article reviews recent in vivo and in vitro progress on the protective role of polydatin against BJDs. An insight into the underlying mechanisms is also presented. It was found that polydatin could promote osteogenesis in vitro, and symptom improvements have been disclosed with animal models of osteoporosis, osteosarcoma, osteoarthritis and rheumatic arthritis. These beneficial effects obtained in laboratory could be mainly attributed to the bone metabolism-regulating, anti-inflammatory, antioxidative, apoptosis-regulating and autophagy-regulating functions of polydatin. However, studies on human subjects with BJDs that can lead to early identification of the clinical efficacy and adverse effects of polydatin have not been reported yet. Accordingly, this review serves as a starting point for pursuing clinical trials. Additionally, future emphasis should also be devoted to the low bioavailability and prompt metabolism nature of polydatin. In summary, well-designed clinical trials of polydatin in patients with BJD are in demand, and its pharmacokinetic nature must be taken into account.

AHY-SLAM: Toward Faster and More Accurate Visual SLAM in Dynamic Scenes Using Homogenized Feature Extraction and Object Detection Method.

At present, SLAM is widely used in all kinds of dynamic scenes. It is difficult to distinguish dynamic targets in scenes using traditional visual SLAM. In the matching process, dynamic points are incorrectly added to the pose calculation with the camera, resulting in low precision and poor robustness in the pose estimation. This paper proposes a new dynamic scene visual SLAM algorithm based on adaptive threshold homogenized feature extraction and YOLOv5 object detection, named AHY-SLAM. This new method adds three new modules based on ORB-SLAM2: a keyframe selection module, a threshold calculation module, and an object detection module. The optical flow method is used to screen keyframes for each frame input in AHY-SLAM. An adaptive threshold is used to extract feature points for keyframes, and dynamic points are eliminated with YOLOv5. Compared with ORB-SLAM2, AHY-SLAM has significantly improved pose estimation accuracy over multiple dynamic scene sequences in the TUM open dataset, and the absolute pose estimation accuracy can be increased by up to 97%. Compared with other dynamic scene SLAM algorithms, the speed of AHY-SLAM is also significantly improved under a guarantee of acceptable accuracy.

Extracellular vesicles from human umbilical cord mesenchymal stem cells reduce lipopolysaccharide-induced spinal cord injury neuronal apoptosis by mediating miR-29b-3p/PTEN.

OBJECTIVE: This study investigated the molecular mechanism of whether hUC-MSCs-EVs repressed PTEN expression and activated the PI3K/AKT pathway through miR-29b-3p, thus inhibiting LPS-induced neuronal injury. METHODS: hUC-MSCs were cultured and then identified. Cell morphology was observed. Alizarin red, oil red O, and alcian blue staining were used for inducing osteogenesis, adipogenesis, and chondrogenesis. EVs were extracted from hUC-MSCs and identified by transmission electron microscope observation and Western blot. SCI neuron model was established by 24h lipopolysaccharide (LPS) induction. After the cells were cultured with EVs without any treatment, uptake of EVs by SCI neurons, miR-29b-3p expression, cell viability, apoptosis, caspase-3, cleaved caspase-3, caspase 9, Bcl-2, PTEN, PI3K, AKT, and p-Akt protein levels, caspase 3 and caspase 9 activities, and inflammatory factors IL-6 and IL-1ß levels were detected by immunofluorescence labeling, RT-qPCR, MTT, flow cytometry, Western blot, caspase 3 and caspase 9 activity detection kits, and ELISA. The binding sites between PTEN and miR-29b-3p were predicted by the database and verified by dual-luciferase assay. RESULTS: LPS-induced SCI cell model was successfully established, and hUC-MSCs-EVs inhibited LPS-induced apoptosis of injured spinal cord neurons. EVs transferred miR-29b-3p into LPS-induced injured neurons. miR-29b-3p silencing reversed EV effects on reducing LPS-induced neuronal apoptosis. miR-29b-3p reduced LPS-induced neuronal apoptosis by targeting PTEN. After EVs-miR-inhi and si-PTEN treatment, inhibition of the PI3K/AKT pathway reversed hUC-MSCs-EVs effects on reducing LPS-induced neuronal apoptosis. CONCLUSION: hUC-MSCs-EVs activated the PI3K/AKT pathway by carrying miR-29b-3p into SCI neurons and silencing PTEN, thus reducing neuronal apoptosis.

Luminous Self-Assembled Fibers of Azopyridines and Quantum Dots Enabled by Synergy of Halogen Bond and Alkyl Chain Interactions.

Herein, a simple approach for the fabrication of luminous self-assembled fibers based on halogen-bonded azopyridine complexes and oleic acid-modified quantum dots (QDs) is reported. The QDs uniformly align on the edge of the self-assembled fibers through the formation of van der Waals force between the alkyl chain of oleic acid on the QD surface and the alkyl chain of the halogen-bonded complexes, 15Br or 15I. Furthermore, the intermolecular interaction mechanism was elucidated by using Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and density functional theory (DFT) calculations. This approach results in retention of the fluorescence properties of the QDs in the fibers. In addition, the bromine-bonded fibers can be assembled into tailored directional fibers upon evaporation of the solvent (tetrahydrofuran) when using capillaries via the capillary force. Interestingly, the mesogenic properties of the halogen-bonded complexes are preserved in the easily prepared halogen-bonded fluorescent fibers; this provides new insight into the design of functional self-assembly materials.

Early surgical intervention for active thoracic spinal tuberculosis patients with paraparesis and paraplegia.

BACKGROUND: To explore the therapeutic effect of early surgical intervention for active thoracic spinal tuberculosis (TB) patients with paraparesis and paraplegia. METHODS: Data on 118 active thoracic spinal TB patients with paraparesis and paraplegia who had undergone surgery at an early stage (within three weeks of paraparesis and paraplegia) from January 2008 to December 2014 were retrospectively analyzed. The operation duration, blood loss, perioperative complication rate, VAS score, ASIA grade and NASCIS score of neurological status rating, Erythrocyte Sedimentation Rate (ESR), C-reactive protein (CRP), kyphotic Cobb's angle, and duration of bone graft fusion were analyzed to evaluate the therapeutic effects of surgery. RESULTS: The mean operating time was 194.2 minutes, and the mean blood loss was 871.2 ml. The perioperative complication rate was 5.9 %. The mean preoperative VAS score was 5.3, which significantly decreased to 3.2 after the operation and continued decreasing to 1.1 at follow up (P<0.05). All cases achieved an increase of at least one ASIA grade after operation. The rate of full neurological recovery for paraplegia (ASIA grade A and B) was 18.0 % and was significantly lower than the rate (100 %) for paraparesis (ASIA grade C and D) (P<0.05). On the NASCIS scale, the difference in the neurological improvement rate between paraplegia (22.2 % ± 14.1 % in sensation and 52.2 % ± 25.8 % in movement) and paraparesis (26.7 % ± 7.5 % in sensation and 59.4 % ± 7.3 % in movement) was remarkable (P<0.05). Mean preoperative ESR and CRP were 73.1 mm /h and 82.4 mg/L, respectively, which showed a significant increase after operation (P>0.05), then gradually decreased to 11.5 ± 1.8 mm/h and 2.6 ± 0.82 mg/L, respectively, at final follow up (P<0.05). The mean preoperative kyphotic Cobb's angle was 21.9º, which significantly decreased to 6.5º after operation (P<0.05) while kyphotic correction was not lost during follow up (P>0.05). The mean duration of bone graft fusion was 8.6 ± 1.3 months. CONCLUSIONS: Early surgical intervention may be beneficial for active thoracic spinal TB patients with paraparesis and paraplegia, with surgical intervention being more beneficial for recovery from paraparesis than paraplegia.

Transcriptome and co-expression network analyses reveal the regulatory pathways and key genes associated with temperature adaptability in the yellow drum (Nibea albiflora).

The yellow drum (Nibea albiflora) is an important marine economy fish, that is widely distributed in the coastal waters of the Northwest Pacific. To understand the molecular regulatory mechanism of the yellow drum under temperature stress, transcriptome analysis was performed under five temperature conditions (10 °C, 15 °C, 20 °C, 24 °C, 28 °C) in the present study. Compared with 20 °C, 163, 401, 276, and 372 differentially expressed genes (DEGs) were obtained at 10 °C, 15 °C, 24 °C and 28 °C, respectively. Gene Ontology (GO) analysis indicated that the DEGs were mainly involved in cellular processes, metabolic processes, catalytic activity, membrane and binding. Meanwhile, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that the temperature adaptive regulation of the yellow drum was mainly involved in signal transduction, metabolism, genetic information and protein processing. Weighted gene co-expression network analysis (WGCNA) showed that HMGB1, STAT4, Noct, C1q and CRT may be the key hub genes in the response of the yellow drum to temperature stress. In addition, 20 genes that may be associated with temperature stress were identified based on comparative analysis between the KEGG enrichment and the WGCNA results. Ten DEGs were selected for further validation using quantitative real-time PCR (qRT-PCR), and the results were consistent with the RNA-seq data. This study explored the transcriptional patterns of the yellow drum under temperature stress and provided fundamental information on the temperature adaptability of this species.

Deep-Learning Approach to Automatic Identification of Facial Anomalies in Endocrine Disorders.

BACKGROUND: Deep learning has the potential to assist the medical diagnostic process. We aimed to identify facial anomalies associated with endocrinal disorders using a deep-learning approach to facilitate the process of diagnosis and follow-up. METHODS: We collected facial images of patients with hypercortisolism and acromegaly, and we augmented these images with additional negative samples from public databases. A model with a pretrained deep-learning network was constructed to automatically identify these hypersecretion statuses based on characteristic facial changes. We compared its performance to that of endocrine experts and further investigated key factors upon which the best performing model focused. FINDINGS: The model achieved areas under the receiver operating characteristic curve of 0.9647 (Cushing's syndrome) and 0.9556 (acromegaly), accuracies of 0.9593 (Cushing's syndrome) and 0.9479 (acromegaly), and recalls of 0.7593 (Cushing's syndrome) and 0.8089 (acromegaly). It performed better than any level of our endocrine experts. Furthermore, the regions of interest on the part of the machine were primarily the same as those upon which the humans focused. INTERPRETATION: Our findings suggest that the deep-learning model learned the facial characters based merely on labeled data without learning prerequisite medical knowledge, and its performance was comparable with professional medical practitioners. The model has the potential to assist in the diagnosis and follow-up of these hypersecretion statuses.

Comparison of diagnostic efficacy of MRI and PET/CT in lung cancer of mouse with spinal metastasis.

This study aimed to compare the diagnostic efficacy of MRI and PET/CT in lung cancer of mouse with spinal metastasis. 40 healthy Balb/c nude mice were selected. 0.1 ml of human lung cancer cell A549 bacterial suspension was injected by the left ventricle injection method to establish a lung cancer spinal metastasis model, and the abnormal signs of the nude mice were closely observed. When the body weight was reduced by 20%, micro PET/CT imaging and small coil MRI imaging were applied after intraperitoneal injection of thiopental anesthesia in nude mice. After the imaging was completed, the nude mouse was dissected and the spinal tumor was removed. The nature of spinal metastases was diagnosed by the pathology department. 5 nude mice died of abdominal infection, 2 nude mice had no spinal tumors, and the remaining 33 nude mice were successfully modeled. 33 nude mice were confirmed by pathology to have 64 metastatic vertebral lesions, among them, there were 7 cervical vertebrae, 24 thoracic vertebrae, 16 lumbar vertebrae, 6 sacral vertebrae and 11 caudal vertebrae. The sensitivity of MRI in the diagnosis of spinal metastases was 78.13%, and specificity was 56.25%. The sensitivity of PET/CT for the diagnosis of spinal metastases was 92.19%, and specificity was 78.95%. The specificity and positive predictive value of PET/CT for the diagnosis of spinal metastases were not significantly different from those of MRI (P> 0.05). The sensitivity, accuracy and negative predictive values were significantly higher than those of MRI (P< 0.05). PET/CT is superior to MRI in the diagnosis of spinal metastases, and its sensitivity, accuracy and negative predictive values were significantly higher than those of MRI (P< 0.05). It is worthy to be further promoted in clinical practice.

Cyclic (alkyl)(amino)carbenes in organic and organometallic methane C-H activation: a DFT and MCSCF study.

Density functional theory (DFT) and multi-configurational self-consistent field (MCSCF) calculations are used to investigate the electronic and steric properties of cyclic (alkyl)(amino)carbenes (CAACs). Calculations show CAACs' diverse electronic characteristics in terms of its donor and acceptor capabilities. Reactions of CAACs in methane C-H bond activation via insertion and also as a supporting ligand (L) for L(Cp)M (M = Co, Rh, Ir) motifs via C-H oxidative addition are studied. The binding energies and buried volumes are calculated for selected CAACs as ancillary ligands to the L(Cp)Rh motif. Overall, CAACs show highly tunable electronic and steric properties by adjusting their substituents and backbones. Although CAAC may not be viable in activating inert small molecules with low polarity like methane, this class of ligand has great potential as ancillary ligands for transition metal complexes in catalysis. Calculation of C-H activation by L(Cp)Ir and L(Cp)Rh with CAACs as supporting ligands show CAACs can render the reaction more amenable to catalysis by destabilizing the oxidative addition products while keeping the reaction mildly exergonic, and the barriers reasonable.

Protective effects of polydatin on multiple organ ischemia-reperfusion injury.

Polydatin(PD), a natural active ingredient isolated from traditional Chinese herb Polygonum cuspidatum, is also found in daily foods such as grapes and red wine. It might play a potential therapeutic role in human health through its anti-inflammatory, anti-oxidant, anti-ischemia injury, anti-apoptosis, conditioning blood lipids and other effects, which makes it increasingly become a hotspot of research. Various studies have shown that PD has a protective effect in the ischemia-reperfusion injury of heart, lungs, kidneys, gastrointestinal tract, cerebra and other organs. However, the specific mechanism of action is less and not completely clear. In this study, we aim to review the protective mechanism of PD in the ischemia-reperfusion injury of various organs, and provide inspiration for future studies.

Quantitative analysis of multicomponents by single marker combined with HPLC fingerprint qualitative analyses for comprehensive evaluation of Aurantii Fructus.

The present study aimed to develop a strategy involving quantitative analysis of multicomponents by single marker in combination with high-performance liquid chromatography fingerprint qualitative analysis for performing the quality control of Aurantii Fructus. The content of 12 components (eriocitrin, neoeriocitrin, narirutin, naringin, hesperidin, neohesperidin, meranzin, poncirin, naringenin, nobiletin, tangeretin, and auraptene) in samples was determined using reliable relative correction factors that were obtained using naringin as an internal reference standard. The new method demonstrated good applicability, and no significant differences were observed between the external standard method and the new method as determined by calculating standard method difference. Qualitative evaluation of samples was conducted using similarity analysis, hierarchical cluster analysis, and quality fluctuation analysis. Chromatographic fingerprint data were divided into three groups by similarity and hierarchical cluster analyses, and seven components may have a more significant impact on the quality of Aurantii Fructus in quality fluctuation analysis. Overall, the study suggests that the qualitative and quantitative analyses of multicomponents using quantitative analysis of multicomponents by single marker combined with chromatographic fingerprinting can be considered good quality criteria for performing quality control and providing technical support for the further pharmacological and pharmaceutical research of Aurantii Fructus.

Intramolecular C-H Functionalization Followed by a [2σ + 2π] Addition via an Intermediate Nickel-Nitridyl Complex.

Irradiation of a disphenoidal Ni(II) azido complex, [Cz tBu(Pyr iPr)2NiN3] (1), revealed an unprecedented nickel complex, [Cz tBu(Pyr iPr)(NH2-Pyr iPr)] (2), in >90% isolated yield. As evidenced by single-crystal X-ray diffraction, 2 is produced by double intramolecular C-H activation of a putative nickel-nitridyl intermediate, [Cz tBu(Pyr iPr)2Ni-⃛N•]. Calculations support the generation of an intermediate with significant nitridyl radical character after the loss of N2, which, in turn, undergoes tandem C-H activations, leading to functionalized intermediates and products. This is an unprecedented example of transient Ni-⃛N•-promoted intramolecular C-H functionalization, followed by a [2σ + 2π] addition, yielding bis-metallacyclic product 2. Complex 2 is also observed from the reaction of Ni(I) precursor Cz tBu(Pyr iPr)2Ni (3) and Me3SiN3, suggesting a unique thermal route toward a masked nickel-nitridyl intermediate.

Computational Study of Methane C-H Activation by Diiminopyridine Nitride/Nitridyl Complexes of 3d Transition Metals and Main-Group Elements.

The C-H bond activation of methane using Ph,MePDI-M≡N [Ph,MePDI = 2,6-(PhN═CMe)2C5H3N] (M = V, Mn, Fe, Co, Ni, Al, or P) has been studied via three reaction pathways: [2σ + 2π] addition, hydrogen atom abstraction (HAA), and direct insertion. The activating ligand is a nitride/nitridyl (N), with diiminopyridine (PDI) as the supporting ligand. Calculations show reasonable C-H activation barriers for Co, Ni, Al, and P Ph,MePDI nitrides, complexes that favor an HAA pathway. Electrophilic Ph,MePDI nitride complexes of the earlier metals with a nucleophilic actor ligand-V, Mn, Fe-follow a [2σ + 2π] addition pathway for methane activation. Free energy barriers for methyl migration, Ph,MePDI-M(CH3)═NH → Ph,MePDI-M-N(H)CH3, are also interesting in the context of alkane functionalization; discriminating factors in this mechanistic step include the strengths of the σ-bond and metal-actor ligand π-bond that are broken and the electrophilicity of the actor ligand to which methyl migrates.

Ctenopharyngodon idella IRF2 and ATF4 down-regulate the transcriptional level of PRKRA.

PRKRA (interferon-inducible double-stranded RNA-dependent protein kinase activator A) is a protective protein which regulates the adaptation of cells to ER stress and virus-stimulated signaling pathways by activating PKR. In the present study, a grass carp (Ctenopharyngodon idella) PRKRA full-length cDNA (named CiPRKRA, KT891991) was cloned and identified. The full-length cDNA is comprised of a 5' UTR (36 bp), a 3' UTR (350 bp) and the longest ORF (882 bp) encoding a polypeptide of 293 amino acids. The deduced amino acid sequence of CiPRKRA contains three typical dsRNA binding motifs (dsRBM). Phylogenetic tree analysis revealed a closer evolutionary relationship of CiPRKRA with other fish PRKRA, especially with Danio rerio PRKRA. qRT-PCR showed that CiPRKRA was significantly up-regulated after stimulation with tunicamycin (Tm) and Poly I:C in C. idella kidney (CIK) cells. To further study its transcriptional regulation, the partial promoter sequence of CiPRKRA (1463 bp) containing one ISRE and one CARE was cloned by Tail-PCR. Subsequently, grass carp IRF2 (CiIRF2) and ATF4 (CiATF4) were expressed in Escherichia coli BL21 and purified by affinity chromatography with the Ni-NTA His-Bind Resin. In vitro, both CiIRF2 and CiATF4 bound to CiPRKRA promoter with high affinity by gel mobility shift assays, revealing that IRF2 and ATF4 might be potential transcriptional regulatory factors for CiPRKRA. Dual-luciferase reporter assays were applied to further investigate the transcriptional regulation of CiPRKRA in vivo. Recombinant plasmid of pGL3-PRKRAPro was constructed and transiently co-transfected into CIK cells with pcDNA3.1-CiIRF2 and pcDNA3.1-CiATF4, respectively. The results showed that both CiIRF2 and CiATF4 significantly decreased the luciferase activity of pGL3-PRKRAPro, suggesting that they play a negative role in CiPRKRA transcription.