Unraveling Intracellular Protein Corona Components of Nanoplastics via Photocatalytic Protein Proximity Labeling.

Bioaccumulation of nanoplastic particles has drawn increasing attention regarding environmental sustainability and biosafety. How nanoplastic particles interact with the cellular milieu still remains elusive. Herein, we exemplify a general approach to profile the composition of a "protein corona" interacting with nanoparticles via the photocatalytic protein proximity labeling method. To enable photocatalytic proximity labeling of the proteome interacting with particles, iodine-substituted BODIPY (I-BODIPY) is selected as the photosensitizer and covalently conjugated onto amino-polystyrene nanoparticles as a model system. Next, selective proximity labeling of interacting proteins is demonstrated using I-BODIPY-labeled nanoplastic particles in both Escherichia coli lysate and live alpha mouse liver 12 cells. Mechanistic studies reveal that the covalent modifications of proteins by an aminoalkyne substrate are conducted via a reactive oxygen species photosensitization pathway. Further proteomic analysis uncovers that mitochondria-related proteins are intensively involved in the protein corona, indicating substantial interactions between nanoplastic particles and mitochondria. In addition, proteostasis network components are also identified, accompanied by consequent cellular proteome aggregation confirmed by fluorescence imaging. Together, this work exemplifies a general strategy to interrogate the composition of the protein corona of nanomaterials by endowing them with photooxidation properties to enable photocatalytic protein proximity labeling function.

Circular RNA EPHA3 suppresses progression and metastasis in prostate cancer through the miR-513a-3p/BMP2 axis.

BACKGROUND: Circular RNAs (circRNAs) may regulate the onset and progression of human malignancies by competitively binding to microRNA (miRNA) sponges, thus regulating the downstream genes. However, aberrant circRNA expression patterns and their biological functions in prostate cancer (PCa) warrant further studies. Our research sought to shed further light on the possible role and molecular mechanism of circEPHA3 action in controlling the growth and metastasis of PCa cells. MATERIALS AND METHODS: circEPHA3 (has_circ_0066596) was initially screened from a previous circRNA microarray and identified following Actinomycin D and RNase R assays. Fluorescence in situ hybridization, biotin-coupled probe RNA pulldown, and dual-luciferase reporter gene assays were performed to examine the relationship between circEPHA3 and miR-513a-3p. The biological role of circEPHA3 in PCa was assessed by CCK8, wound healing, Transwell assays, and animal experiments. RESULTS: We identified a novel circular RNA, circEPHA3 (has_circ_0066596), which was down-regulated in high-grade PCa tissues and cell lines. The outcomes of CCK8, wound healing, Transwell assays, and animal experiments revealed that circEPHA3 prohibited the progression and metastasis of PCa in vivo and in vitro. Mechanistically, circEPHA3 was directly bound to miR-513a-3p and regulated the downstream gene, BMP2, thereby serving as a tumor suppressor in PCa. CONCLUSIONS: As a tumor suppressor, circEPHA3 inhibited the proliferation and metastasis of PCa cells through the miR-513a-3p/BMP2 axis, suggesting that circEPHA3 might be a potential therapeutic target for PCa.

The R2R3-MYB transcription factor FaMYB63 participates in regulation of eugenol production in strawberry.

The biosynthetic pathway of volatile phenylpropanoids, including 4-allyl-2-methoxyphenol (eugenol), has been investigated in petunia (Petunia hybrida). However, the regulatory network for eugenol accumulation in strawberry (Fragaria × ananassa Duch.) fruit remains unclear. Here, an R2R3-type MYB transcription factor (TF; FaMYB63) was isolated from strawberry by yeast one-hybrid (Y1H) screening using the promoter of the FaEGS1 (eugenol synthase 1 [EGS 1]) gene, which encodes the enzyme responsible for the last step in eugenol biosynthesis. FaMYB63 is phylogenetically distinct from other R2R3-MYB TFs, including FaEOBІІ (EMISSION OF BENZENOID II [EOBII]), which also participates in regulating eugenol biosynthesis in strawberry receptacles. Reverse transcription quantitative PCR (RT-qPCR) assays showed that the expression of FaMYB63 was tissue-specific and consistent with eugenol content through strawberry fruit development, was repressed by abscisic acid, and was activated by auxins (indole-3-acetic acid). Overexpression and RNA interference-mediated silencing of FaMYB63 resulted in marked changes in the transcript levels of the biosynthetic genes FaEGS1, FaEGS2, and FaCAD1 (cinnamyl alcohol dehydrogenase 1 [CAD1]) and, thereby, the accumulation of eugenol. Electrophoretic mobility shift, Y1H, GUS activity, and dual-luciferase activity assays demonstrated that the transcript levels of FaEOBІІ and FaMYB10 were regulated by FaMYB63, but not the other way around. Together, these results demonstrate that FaMYB63 directly activates FaEGS1, FaEGS2, FaCAD1, FaEOBІІ, and FaMYB10 to induce eugenol biosynthesis during strawberry fruit development. These findings deepen the understanding of the regulatory network that influences eugenol metabolism in an edible fruit crop.

Exposure to bisphenols, parabens and phthalates during pregnancy and postpartum anxiety and depression symptoms: Evidence from women with twin pregnancies.

BACKGROUND: Women are vulnerable to suffer from the common mental disorders like anxiety and depression during the postpartum period. Exposure to bisphenols, parabens, and phthalates has been linked to anxiety and depression symptoms in the general population. However, little is known about their impacts on postpartum women. OBJECTIVE: To evaluate the effects of individual and joint exposure to 11 nonpersistent chemicals during pregnancy on postpartum anxiety and depression. METHODS: Among 278 mothers from the Wuhan Twin Birth Cohort (WTBC), bisphenols, parabens, and phthalate metabolites were measured in maternal urine samples from each trimester. Self-rating Anxiety Scale (SAS) and Edinburgh Postnatal Depression Scale (EPDS) were administrated at early pregnancy and 1 month and 6 months postpartum to determine anxiety and depression symptoms, respectively. Associations between urinary chemical biomarkers (individual or mixtures) and anxiety and depression symptoms were estimated using multiple informant model and quantile-based g-computation. RESULTS: With adjustment for confounders, one quartile increase in the overall chemical mixture (bisphenols, parabens and phthalate metabolites) during the second trimester was associated with 1.03-point (95% CI: 0.07, 1.99, P = 0.036) higher EPDS score at 1 month postpartum, in which bisphenol A (BPA) and bisphenol F (BPF) contributed the most to the positive association. Consistent effects were also observed in the multiple informant models. We found that second-trimester BPA and BPF exposure individually showed the strongest and significant associations with anxiety and depression symptoms, and some of associations differed across trimesters (Ptrimester-int < 0.05). CONCLUSIONS: Second-trimester nonpersistent chemical exposure was associated with increased postpartum anxiety and depression symptoms.

In situ self-assembling Au-DNA complexes for targeted cancer bioimaging and inhibition.

Cancer remains one of the most challenging diseases to treat. For accurate cancer diagnosis and targeted therapy, it is important to assess the localization of the affected area of cancers. The general approaches for cancer diagnostics include pathological assessments and imaging. However, these methods only generally assess the tumor area. In this study, by taking advantage of the unique microenvironment of cancers, we effectively utilize in situ self-assembled biosynthetic fluorescent gold nanocluster-DNA (GNC-DNA) complexes to facilitate safe and targeted cancer theranostics. In in vitro and in vivo tumor models, our self-assembling biosynthetic approach allowed for precise bioimaging and inhibited cancer growth after one injection of DNA and gold precursors. These results demonstrate that in situ bioresponsive self-assembling GNC-PTEN (phosphatase and tensin homolog) complexes could be an effective noninvasive technique for accurate cancer bioimaging and treatment, thus providing a safe and promising cancer theranostics platform for cancer therapy.

Insights from comparative transcriptome analysis in the responses of Pb-tolerant fungi Curvularia tsudae to Pb stress.

The fungus Curvularia tsudae can survive in environments that are extremely contaminated by heavy metals; however, the underlying molecular mechanisms of heavy metal tolerance are not clear. In this study, we determined the effects of lead (Pb) stress on the growth of C. tsudae and used RNA-Seq to identify significant genes and biological processes involved. The present study showed that C. tsudae had an outstanding resistant capacity to Pb stress and could survive at a concentration of 1600 mg L-1 Pb. Although an obvious inhibition on the growth was observed, the fungus exhibited tolerance as it continued to grow at a Pb concentration of 1600 mg L-1 for seven days. A total of 9997 (9020 up and 977 down) differentially expressed genes (DEGs) were detected in the mycelium of C. tsudae at Pb free (0 mg L-1) and Pb stressed samples. Pathway enrichment analysis identified several biological processes for managing Pb stress. Genes involved in carbohydrate metabolism tended to be modulated in response to Pb stress, while amino acids and the lipid metabolism would also be induced by Pb stress, and up-regulated genes involved in antioxidant substances and ABC transporters may be committed to high Pb tolerance. Our study contributes to the current literature on C. tsudae response to Pb stress and provides a useful reference for fungi as bioremediators in heavy metal-contaminated environments.

Enabling Photo-Crosslinking and Photo-Sensitizing Properties for Synthetic Fluorescent Protein Chromophores.

Synthetic fluorescent protein chromophores have been reported for their singlet state fluorescence properties and applications in bioimaging, but rarely for the triplet state chemistries. Herein, we enabled their photo-sensitizing and photo-crosslinking properties through rational modulations. Extension of molecular conjugation and introduction of heavy atoms promoted the generation of reactive oxygen species. Unlike other photosensitizers, these chromophores selectively photo-crosslinked aggregated proteins and uncovered the interactome profiles. We also exemplified their general applications in chromophore-assisted light inactivation, photodynamic therapy and photo induced polymerization. Theoretical calculation, pathway analysis and transient absorption spectroscopy provided mechanistic insights for this triplet state chemistry. Overall, this work expands the function and application of synthetic fluorescent protein chromophores by enabling their triplet excited state properties.

Increased transient receptor potential canonical 3 activity is involved in the pathogenesis of detrusor overactivity by dynamic interaction with Na+/Ca2+ exchanger 1.

Transient receptor potential canonical 3 (TRPC3) is a nonselective cation channel, and its dysfunction is the basis of many clinical diseases. However, little is known about its possible role in the bladder. The purpose of this study was to explore the function and mechanism of TRPC3 in partial bladder outlet obstruction (PBOO)-induced detrusor overactivity (DO). We studied 31 adult female rats with DO induced by PBOO (the DO group) and 40 sham-operated rats (the control group). Here we report that the expression of TRPC3 in the bladder of DO rats increased significantly. Furthermore, PYR10, which can selectively inhibit the TRPC3 channel, significantly reduced bladder excitability in DO and control rats, but the decrease of the bladder excitability of DO rats was more obvious. PYR10 significantly reduced the intracellular calcium concentration in smooth muscle cells (SMCs) in DO and control rats. Finally, Na+/Ca2+ exchanger 1 (NCX1) colocalizes with TRPC3 and affects its expression and function. Collectively, these results indicate that TRPC3 plays an important role in the pathogenesis of DO through a synergistic effect with NCX1. TRPC3 and NCX1 may be new therapeutic targets for DO.

Covalent Solvatochromic Proteome Stress Sensor Based on the Schiff Base Reaction.

Covalent-type probes or sensors have been seldom reported for aggregated proteins. Herein, we reported a series of covalent solvatochromic probes to selectively modify and detect aggregated proteomes through the Schiff base reaction. Such covalent modification was discovered by serendipity using the P1 probe with an aldehyde functional group, exhibiting enhanced fluorescence intensity and unusually large blue shift upon protein aggregation. Supported by the biochemical and mass spectrometry results, we identified that this probe can modify the lysine residue of aggregated proteins selectively over folded ones via the Schiff base reaction. The generality of designing such a covalent-type probe was demonstrated in multiple probe scaffolds using different model proteins. Finally, we exploited the distinct solvatochromism of P1 after Schiff base linkage with aggregated proteins to visualize the distinct morphology of aggregated proteomes, as well as to quantify the polarity heterogeneity inside it. This work may intrigue the exploration of other chemical reaction types to covalently functionalize aggregated proteins that were difficult to analyze.

Whole-plant microbiome profiling reveals a novel geminivirus associated with soybean stay-green disease.

Microbiota colonize every accessible plant tissue and play fundamental roles in plant growth and health. Soybean stay-green syndrome (SGS), a condition that causes delayed leaf senescence (stay-green), flat pods and abnormal seeds of soybean, has become the most serious disease of soybean in China. However, the direct cause of SGS is highly debated, and little is known about how SGS affect soybean microbiome dynamics, particularly the seed microbiome. We studied the bacterial, fungal, and viral communities associated with different soybean tissues with and without SGS using a multi-omics approach, and investigated the possible pathogenic agents associated with SGS and how SGS affects the assembly and functions of plant-associated microbiomes. We obtained a comprehensive view of the composition, function, loads, diversity, and dynamics of soybean microbiomes in the rhizosphere, root, stem, leaf, pod, and seed compartments, and discovered that soybean SGS was associated with dramatically increased microbial loads and dysbiosis of the bacterial microbiota in seeds. Furthermore, we identified a novel geminivirus that was strongly associated with soybean SGS, regardless of plant cultivar, sampling location, or harvest year. This whole-plant microbiome profiling of soybean provides the first demonstration of geminivirus infection associated with microbiota dysbiosis, which might represent a general microbiological symptom of plant diseases.

Genome of Hippophae rhamnoides provides insights into a conserved molecular mechanism in actinorhizal and rhizobial symbioses.

Sea buckthorn (Hippophae rhamnoides), a horticulturally multipurpose species in the family Elaeagnaceae, can build associations with Frankia actinomycetes to enable symbiotic nitrogen-fixing. Currently, no high-quality reference genome is available for an actinorhizal plant, which greatly hinders the study of actinorhizal symbiotic nodulation. Here, by combining short-read, long-read and Hi-C sequencing technologies, we generated a chromosome-level reference genome of H. rhamnoides (scaffold N50: 65 Mb, and genome size: 730 Mb) and predicted 30 812 protein-coding genes mainly on 12 pseudochromosomes. Hippophae rhamnoides was found to share a high proportion of symbiotic nodulation genes with Medicago truncatula, implying a shared molecular mechanism between actinorhizal and rhizobial symbioses. Phylogenetic analysis clustered the three paralogous NODULE INCEPTION (NIN) genes of H. rhamnoides with those of other nodulating species, forming the NIN group that most likely evolved from the ancestral NLP group. The genome of H. rhamnoides will help us to decipher the underlying genetic programming of actinorhizal symbiosis, and our high-quality genome and transcriptomic resources will make H. rhamnoides a new excellent model plant for actinorhizal symbiosis research.

Late-Stage Dehydroxyazidation of Alcohols Promoted by Trifunctional Hypervalent Azido-Iodine(III) Reagents.

The development of convenient new methods for the synthesis of organic azides is highly desirable. Herein, we report a practical method for dehydroxyazidation of alcohols via an SN 2 pathway involving PPh3 and trifunctional benziodazolone-based hypervalent azido-iodine(III) reagents, which function as an electrophilic center, an azido source, and a base. This mild, chemoselective method was used for late-stage azidation of structurally complex alcohols, as well as for a new synthetic route to the antiepileptic drug rufinamide. The reaction mechanism was also investigated both experimentally and computationally.

An endorectal ultrasound-based radiomics signature for preoperative prediction of lymphovascular invasion of rectal cancer.

OBJECTIVE: To investigate whether radiomics based on ultrasound images can predict lymphovascular invasion (LVI) of rectal cancer (RC) before surgery. METHODS: A total of 203 patients with RC were enrolled retrospectively, and they were divided into a training set (143 patients) and a validation set (60 patients). We extracted the radiomic features from the largest gray ultrasound image of the RC lesion. The intraclass correlation coefficient (ICC) was applied to test the repeatability of the radiomic features. The least absolute shrinkage and selection operator (LASSO) was used to reduce the data dimension and select significant features. Logistic regression (LR) analysis was applied to establish the radiomics model. The receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA) were used to evaluate the comprehensive performance of the model. RESULTS: Among the 203 patients, 33 (16.7%) were LVI positive and 170 (83.7%) were LVI negative. A total of 5350 (90.1%) radiomic features with ICC values of ≥ 0.75 were reported, which were subsequently subjected to hypothesis testing and LASSO regression dimension reduction analysis. Finally, 15 selected features were used to construct the radiomics model. The area under the curve (AUC) of the training set was 0.849, and the AUC of the validation set was 0.781. The calibration curve indicated that the radiomics model had good calibration, and DCA demonstrated that the model had clinical benefits. CONCLUSION: The proposed endorectal ultrasound-based radiomics model has the potential to predict LVI preoperatively in RC.

Clinical study of auricular point seed burying combined with fire dragon pot moxibustion in perimenopausal women with insomnia.

OBJECTIVE: To intervene the insomnia symptoms of perimenopausal women by auricular point seed burying combined with fire dragon pot moxibustion, in order to improve the quality of sleep and life of the participants. METHODS: Seventy female participants with perimenopausal insomnia who were treated with Chinese medicine techniques from January 2020 to October 2020 were randomly divided into a control group and an observation group, with 35 participants in each group. Participants in the control group were treated with the traditional Chinese medicine nursing intervention of burying seeds at auricular points. And participants in the observation group were additionally treated with fire dragon pot moxibustion. After 10 weeks of intervention, the Pittsburgh Sleepiness Index (PSQI), self-assessment scores of anxiety (SAS) and depression (SDS), and treatment efficacy of the two groups were compared, respectively. RESULTS: Before the intervention, there was no statistically significant difference in general information, sleep index scores, SAS, SDS scores between the two groups (p > 0.05). After the intervention, the SAS, SDS, and PSQI scores were significantly lower than the control group. Compared with the control group, the time to fall asleep was shorter and the duration of total sleep was longer in the observation group (p < 0.05). The treatment efficacy was better in the observation group (p < 0.05). CONCLUSION: Auricular point seed burying combined with fire dragon pot moxibustion therapy can be more effect than auricular point seed burying alone in treating perimenopausal women with insomnia.

Association of liver abnormalities with in-hospital mortality in patients with COVID-19.

BACKGROUND & AIMS: The evolution and clinical significance of abnormal liver chemistries and the impact of hepatitis B infection on outcome in patients with COVID-19 is not well characterized. This study aimed to explore these issues. METHODS: This large retrospective cohort study included 2,073 patients with coronavirus disease 2019 (COVID-19) and definite outcomes in Wuhan, China. Longitudinal liver function tests were conducted, with associated factors and risk of death determined by multivariate regression analyses. A prognostic nomogram was formulated to predict the survival of patients with COVID-19. The characteristics of liver abnormalities and outcomes of patients with COVID-19, with and without hepatitis B, were compared after 1:3 propensity score matching. RESULTS: Of the 2,073 patients, 1,282 (61.8%) had abnormal liver chemistries during hospitalization, and 297 (14.3%) had a liver injury. The mean levels of aspartate aminotransferase (AST) and direct bilirubin (D-Bil) increased early after symptom onset in deceased patients and showed disparity compared to levels in discharged patients throughout the clinical course of the disease. Abnormal AST (adjusted hazard ratio [HR] 1.39; 95% CI 1.04-1.86, p = 0.027) and D-Bil (adjusted HR 1.66; 95% CI 1.22-2.26; p = 0.001) levels at admission were independent risk factors for mortality due to COVID-19. A nomogram was established based on the results of multivariate analysis and showed sufficient discriminatory power and good consistency between the prediction and the observation. HBV infection in patients did not increase the risk of poor COVID-19-associated outcomes. CONCLUSIONS: Abnormal AST and D-Bil levels at admission were independent predictors of COVID-19-related mortality. Therefore, monitoring liver chemistries, especially AST and D-Bil levels, is necessary in hospitalized patients with COVID-19. LAY SUMMARY: Liver test abnormalities (in particular elevations in the levels of aspartate aminotransferase [AST] and direct bilirubin [D-Bil]) were observed after symptom onset in patients who went on to die of coronavirus disease 2019 (COVID-19). Abnormal levels of AST and D-Bil at admission were independent predictors of COVID-19-related mortality. HBV infection in patients did not increase the risk of poor COVID-19-associated outcomes.

A Mid-to-Long Term Comprehensive Evaluation of Psychological Distress and Erectile Function in COVID-19 Recovered Patients.

BACKGROUND: The psychological and sexual health of different populations are negatively affected during the coronavirus disease 2019 (COVID-19) pandemic. However, little is known about psychological distress and erectile function of male recovered patients with COVID-19 in the long term. AIM: We aimed to evaluate psychological distress and erectile function of male recovered patients with COVID-19 in the mid-to-long terms. METHODS: We recruited 67 eligible male recovered patients with COVID-19 and followed them up twice within approximately 6 months of recovery time. The psychological distress and erectile function were assessed by validated Chinese version of paper questionnaires. OUTCOMES: The primary outcomes were Symptom Checklist 90 questionnaire for psychological distress and International Index of Erectile Function-5 for erectile function. RESULTS: In the first visit, COVID-19 patients with a median recovery time of 80 days mainly presented the following positive symptoms: Obsessive-Compulsive, additional items (ADD), Hostility, Interpersonal Sensitivity, Depression, and Somatization; while the dimension scores in Somatization, Anxiety, ADD, and Phobia were higher than Chinese male norms. Besides, the prevalence of erectile dysfunction (ED) in the first-visit patients was significantly higher than Chinese controls. In the second visit, the primary psychological symptoms of COVID-19 patients with a median recovery time of 174 days were Obsessive-Compulsive, ADD, Interpersonal Sensitivity, and Hostility, while all dimensions scores of Symptom Checklist 90 were lower than Chinese male norms. Moreover, second-visit patients had no significant difference with Chinese controls in ED prevalence. In addition, it suggested that GSI was the independent risk factor for ED in the regression analysis for the first-visit patients. CLINICAL IMPLICATIONS: The study showed the changes of psychological symptoms and erectile function in COVID-19 recovered patients, and provided reference on whether psychological and sexual supports are needed after a period of recovery. STRENGTHS AND LIMITATIONS: To our knowledge, it is the first study to comprehensively evaluate the psychological distress and erectile function of COVID-19 recovered patients in the mid-to-long terms. The main limitations were the low number of analyzed participants, and the psychological distress and erectile function of healthy Chinese men over the same period were not evaluated, and the psychological and sexual related data of participants prior to COVID-19 were not available. Additionally, there was a selection bias in comparing COVID-19 patients with healthy controls. CONCLUSION: With less impact of COVID-19 event, the impaired erectile function and psychological distress improved in COVID-19 recovered patients with a recovery time of nearly half a year. Hu B, Ruan Y, Liu K, et al. A Mid-to-Long Term Comprehensive Evaluation of Psychological Distress and Erectile Function in COVID-19 Recovered Patients. J Sex Med 2021;18:1863-1871.

Phosphorylation of MtRopGEF2 by LYK3 mediates MtROP activity to regulate rhizobial infection in Medicago truncatula.

The formation of nitrogen-fixing no dules on legume roots requires the coordination of infection by rhizobia at the root epidermis with the initiation of cell divisions in the root cortex. During infection, rhizobia attach to the tip of elongating root hairs which then curl to entrap the rhizobia. However, the mechanism of root hair deformation and curling in response to symbiotic signals is still elusive. Here, we found that small GTPases (MtRac1/MtROP9 and its homologs) are required for root hair development and rhizobial infection in Medicago truncatula. Our results show that the Nod factor receptor LYK3 phosphorylates the guanine nucleotide exchange factor MtRopGEF2 at S73 which is critical for the polar growth of root hairs. In turn, phosphorylated MtRopGEF2 can activate MtRac1. Activated MtRac1 was found to localize at the tips of root hairs and to strongly interact with LYK3 and NFP. Taken together, our results support the hypothesis that MtRac1, LYK3, and NFP form a polarly localized receptor complex that regulates root hair deformation during rhizobial infection.

Structured H∞ Control for Spacecraft with Flexible Appendages.

Spacecraft with large flexible appendages are characterized by multiple system modes. They suffer from inherent low-frequency disturbances in the operating environment that consequently result in considerable interference in the operational performance of the system. It is required that the control design ensures the system's high pointing precision, and it is also necessary to suppress low-frequency resonant interference as well as take into account multiple performance criteria such as attitude stability and bandwidth constraints. Aiming at the comprehensive control problem of this kind of flexible spacecraft, we propose a control strategy using a structured H-infinity controller with low complexity that was designed to meet the multiple performance requirements, so as to reduce the project cost and implementation difficulty. According to the specific resonant mode of the system, the design strategy of adding an internal mode controller, a trap filter, and a series PID controller to the structured controller is proposed, so as to achieve the comprehensive control goals through cooperative control of multiple control modules. A spacecraft with flexible appendages (solar array) is presented as an illustrative example in which a weighted function was designed for each performance requirement of the system (namely robustness, stability, bandwidth limit, etc.), and a structured comprehensive performance matrix with multiple performance weights and decoupled outputs was constructed. A structured H-infinity controller meeting the comprehensive performance requirements is given, which provides a structured integrated control method with low complexity for large flexible systems that is convenient for engineering practice, and provides a theoretical basis and reference examples for structured H-infinity control. The simulation results show that the proposed controller gives better control performance compared with the traditional H-infinity one, and can successfully suppress the vibration of large flexible appendages at 0.12 Hz and 0.66 Hz.

Extraction and bioinformatics analysis of Chlamydia trachomatis LpxA.

OBJECTIVE: The aim of this study is to clone the LpxA gene of Chlamydia trachomatis and analyze its biological characteristics. METHODS: Specific primers were designed according to the sequence of Ct LpxA gene. LpxA gene was amplified by PCR and connected to pMD18-T vectors. Positive clones were selected for PCR and DNA sequencing. Finally, bioinformatics software was used to analyze the biological properties of LpxA protein. RESULTS: The total length of LpxA gene was 840 bp, encoding 280 amino acids. LpxA protein has no signal peptide and was located in bacterial cytoplasm. The prediction of secondary structure showed that the α-helix, extended strand, ß-turn and random coil accounted for 19.6%, 32.8%, 11.4% and 36%, respectively. According to the prediction of tertiary structure, three identical LpxA molecules constituted homologous trimers. It was predicted that there were 11 B cell epitopes in LpxA. CONCLUSION: Ct Lpxa gene was cloned, and LpxA protein structure and function were predicted.

Ring Expansion Fluorination of Unactivated Cyclopropanes Mediated by a New Monofluoroiodane(III) Reagent.

Herein, we report a new strategy for carbon-carbon bond scission and intramolecular ring expansion fluorination of unactivated cyclopropanes, which was accomplished with a new hypervalent fluoroiodane(III) reagent 1. This novel method delivers medicinally relevant 4-fully substituted fluoropiperidines in moderate to high yields with excellent regio- and diastereoselectivity. Reagent 1, which has an N-acetylbenziodazole framework, was readily synthesized via three steps in 76 % overall yield and was characterized by NMR spectroscopy and X-ray crystallography. Owing to the presence of a secondary I⋅⋅⋅O bonding interaction between the λ3 -iodane atom and the carbonyl oxygen of the acetyl group of the N-acetylbenziodazole framework, 1 has excellent stability and can be stored at ambient temperature for 6 months without any detectable decomposition. Density functional theory calculations and experimental studies showed that the reaction proceeds via a carbocation intermediate that readily combines with a fluoride ion to generate the product.