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Salicylic acid (SA) plays a pivotal role in delaying fruit ripening and senescence. However, little is known about its underlying mechanism of action. In this study, RNA sequencing was conducted to analyze and compare the transcriptome profiles of SA-treated and control pear fruits. We found a total of 159 and 419 genes differentially expressed between the SA-treated and control pear fruits after 12 and 24 h of treatment, respectively. Among these differentially expressed genes (DEGs), 125 genes were continuously differentially expressed at both treatment times, and they were identified as candidate genes that might be associated with SA-regulated fruit ripening and senescence. Bioinformatics analysis results showed that 125 DEGs were mainly associated with plant hormone biosynthesis and metabolism, cell wall metabolism and modification, antioxidant systems, and senescence-associated transcription factors. Additionally, the expression of several candidate DEGs in ripening and senescent pear fruits after SA treatments were further validated by quantitative real-time PCR (qRT-PCR). This study provides valuable information and enhances the understanding of the comprehensive mechanisms of SA-meditated pear fruit ripening and senescence.

Objective: To report a rare case of endometrial yolk sac tumor (YST) and review published cases of YST of the endometrium. Case report: A 68-year-old female presented with intermittent vaginal spotting for nine months. An endometrial biopsy showed adenocarcinoma. Complete surgical staging operation was performed and the final pathology revealed stage II endometrial yolk sac tumor. The post-operative α-fetoprotein (AFP) level was 133.4 ng/mL. Post-operative adjuvant chemotherapy with bleomycin, etoposide, and cisplatin (BEP) regimen was prescribed for 6 cycles. AFP levels were normal before the fourth cycle of chemotherapy. She is disease free 6 months after completion of therapy. Conclusion: Primary YSTs arising in the endometrium is an extremely rare disease especially in postmenopausal women. Complete surgical staging operation with adjuvant chemotherapy will lead to good outcome in this disease. Keywords: Yolk sac tumor, Endometrial cancer, Adjuvant chemotherapy

Well placement optimization is usually complex, nonlinear and multimodal in oil field development. Well placement is usually optimized by coupling reservoir numerical simulator with population-based algorithms. This method is computationally expensive, as they require many fitness function calls during the optimization process which limits its optimization efficiency. In this work, the direct mapping of productivity potential (DMPP) technique is applied for well placement optimization problems. Threshold value of productivity potential (TVPP) coupled with particle swarm optimization (PSO) is first proposed as a screening process to reduce the number of objective function evaluation based on DMPP. PUNQ-S3 model is applied to analyze the adaptability of DMPP and feasibility of TVPP for well placement optimization. Results demonstrate TVPP management strategy can significantly reduce the optimization time (OT) and keep the optimization effect at the same time. Taken it total, the proposed management strategy is simple but very efficient.

Summary Background The outbreak of COVID-19 has led to international concern. We aimed to establish an effective screening strategy in Shanghai, China, to aid early identification of patients with COVID-19. Methods We did a multicentre, observational cohort study in fever clinics of 25 hospitals in 16 districts of Shanghai. All patients visiting the clinics within the study period were included. A strategy for COVID-19 screening was presented and then suspected cases were monitored and analysed until they were confirmed as cases or excluded. Logistic regression was used to determine the risk factors of COVID-19. Findings We enrolled patients visiting fever clinics from Jan 17 to Feb 16, 2020. Among 53 617 patients visiting fever clinics, 1004 (1·9%) were considered as suspected cases, with 188 (0·4% of all patients, 18·7% of suspected cases) eventually diagnosed as confirmed cases. 154 patients with missing data were excluded from the analysis. Exposure history (odds ratio [OR] 4·16, 95% CI 2·74–6·33; p

Background: Systematic assessment of the impact of age on the clinical characteristics and outcomes of coronavirus disease 2019 (COVID -19) is crucial for clini

Background: The outbreak of novel coronavirus disease 2019 (COVID-19) has led to increasing international concern. Effective screening strategy and early recognition of the disease are crucial to limiting spread of this worldwide challenge. Methods: Fever clinics of 25 hospitals evenly distributed in 16 Districts of Shanghai were selected. All patients visiting the fever clinics from the begin of the outbreak of Shanghai (17 January 2020) to 16 February were enrolled. A standardized procedure for COVID-19 screening was presented and all the suspected cases were monitored and analyzed till they were confirmed or excluded. Findings: Among 53617 patients who visiting fever clinics, 1004 (1·87%) were considered as suspected cases, with 188 (0·35% of all patients, 18·73% of suspected cases) diagnosed as confirmed cases finally. Compared with the excluded cases, confirmed cases were older and the highest temperatures were relatively lower (p

Microgrid provides an effective approach to utilize distributed renewable energies (DREs). Given the ongoing transformation of distribution system with high penetration of DREs, coordinating and consuming a large amount of distributed generators (DGs) within one single microgrid has become increasingly infeasible. Interconnecting multiple microgrids as a microgrid cluster is an effective way to improve the operation quality of large-scale DG integration. As the keys to the microgrid clusters, the flexible configurations and coordinated operation among multiple microgrids have not been adequately addressed. In order to solve this problem, a novel architecture for multiple microgrids and its coordinated control schemes are designed. Firstly, the advanced microgrid interface named hybrid unit of common coupling (HUCC) is designed and utilized in replacement of the conventional point of common coupling (PCC). The HUCC employs modular multilevel converter (MMC) as its core component and provides both AC and DC interfaces. Then, this paper puts forward a HUCC-based architecture for multiple microgrids where microgrids are grid-connected via the AC interfaces and interconnected via the DC interfaces. Based on the proposed architecture, coordinated control schemes under different operation scenarios are came up with at last. A case study of the HUCC-based multiple microgrids is performed in PSCAD/EMTDC on the basis of the demonstration project in Guangxi, China. The simulation results show that the interconnected microgrids with the proposed architecture and control schemes operates effectively and efficiently under different operation scenarios. The proposed architecture and control schemes not only enhance the large-scale integration of DREs, but realize the optimal use of DGs as well.

Coastal eutrophication has resulted in the rapid loss and deterioration of seagrass beds worldwide. The high concentration of ammonium in eutrophic aquatic environments has been invoked as the main cause. In this study, leaves and roots of the seagrass Zostera marina were treated with simulated eutrophic seawater with elevated ammonium concentrations. The tolerance to ammonium stress and mechanism of nitrogen metabolism detoxification in different tissues were investigated. The results showed that high ammonium stress significantly affected the growth of leaves and had a negative effect on photosynthesis. The root activity of Z. marina was not inhibited at ammonium concentrations of ≤100 mg/L, indicating that the roots exhibited tolerance to ammonium stress. Increasing ammonium concentrations led to a higher increase of ammonium and free amino acid (FAA) contents in leaves than in roots. However, nitrogen storage decreased in Z. marina leaves after high ammonium treatments. The enzyme activity and gene expression of glutamine synthetase (GS) in roots were significantly higher than in the leaves even under ammonium stress. Meanwhile, ammonium stress increased the enzyme activities and gene expression of glutamate synthase (GOGAT) and glutamate dehydrogenase (GDH) in roots, which suggested that the roots had a strong ability to assimilate ammonium under ammonium stress. In contrast, although the GOGAT and GDH activity and gene expression in the leaves were initially increased, they significantly decreased when the ammonium concentration exceeded 100 mg/L. These results indicated that the concentration of 100 mg/L might be a threshold marking a transition from tolerance to toxicity for the leaves. Our study demonstrates that Z. marina leaves could be prone to higher damage than roots because the mechanism of ammonium assimilation in leaves is more susceptible to ammonium toxicity.

Background Persistent cough and large amounts of purulent sputum affects many bronchiectasis patients. No studies have evaluated the efficacy and safety of bronchoscopic airway clearance therapy and bronchoalveolar lavage (B-ACT) for non-cystic fibrosis bronchiectasis patients with acute exacerbation. Methods A randomised controlled trial was conducted to explore the efficacy and safety of B-ACT among 189 bronchiectasis inpatients from February 1, 2018 to February 28, 2019. The primary outcome was the time to first acute exacerbation. Secondary outcomes included changes of health-related scores, length of hospital stay, hospitalization expenses and incidences of adverse events. Findings B-ACT therapy significantly prolonged the median days to first acute exacerbation when compared with control group (198 vs 168 days, HR 0·555 (0·322-0·958), p=0·012; effect size(r)= 0·94). Further analysis showed that B-ACT therapy was more beneficial for these patients with severe disease and greater symptoms. COPD Assessment Test (CAT) scores improved significantly on the third day (5·45 vs 4·85, 0·60 (0·09-1·11), p=0·023), and Leicester Cough Questionnaire (LCQ) scores improved obviously on the third and seventh days (1·53 vs 1·23, 0·30 (0·05-0·55), p=0·044; 1·66 vs 1·32, 0·34 (0·08-0·60), p=0·022; respectively) after B-ACT therapy. Adverse events associated with B-ACT were mostly transient and mild. Differences of the lengths of hospital stay and hospitalization expenses in both group was not significant. Interpretation B-ACT therapy significantly prolonged the time to first acute exacerbation after discharge, highlighting the importance of B-ACT therapy focused on symptom improvements in preventing exacerbation. Funding National Natural Science Foundation of China. Trial registry ClinicalTrials.gov; No.:NCT03643302; URL: www.clinicaltrials.gov .

The thermal stability of triple helical structure plays a critical role in collagen biosynthesis, function and degradation. CD technique was utilized to characterize the thermal stability of synthetic collagen mimic peptides. Fluorescence spectroscopy is widely used with easy access all around the world because of its inexpensive instrumentation, low operation cost, easy operation, and high sensitivity. Here we have developed an alternative fluorescence method to detect the thermal stability of collagen mimic peptides. We have demonstrated that fluorescence spectroscopy could measure the thermal stability of collagen mimic peptides with low concentrations under different circumstances. This highly sensitive fluorescence self-quenching assay will greatly expedite the studies of sequence-dependent properties of collagen mimic peptides, and it has great potential in the application of determining the thermal stability of triple helix systems such as collagens, collectins, adiponectin, macrophage scavenger and C1q.

The natural Leymus chinensis grassland in western Jilin Province of NE China has been extensively degraded, thereby restricting the development of animal husbandry. Using theory of ecological stoichiometry homeostasis, this study investigated the homeostasis of L. chinensis at different degradation stages in the research area using a homeostasis model. Results showed that the degraded grassland generally had lower soil carbon (C), nitrogen (N) and phosphorus (P) compared with normal L. chinensis grassland. In particular, the degraded grassland exhibited severe shortage of P, but L. chinensis showed strong homeostasis. Except for C in the roots and leaves and P in stems, the N, P and corresponding ratios had higher homeostasis than 1, between 1.53 and 15.92. The homeostasis of N in L. chinensis was higher than that of P, and the homeostasis of C/P was higher than that of C/N and N/P. L. chinensis absorbs and uses nutritive elements in a conservative manner, which enables it to remain productive during changes in the external environment. Therefore, grassland degradation control should prioritize the protection of dominant species. Appropriate use of N and P fertilizers is suggested for the recovery of the seriously degraded L. chinensis grassland ecosystem.

An experimental study was taken to investigate the cumulative seismic damage of reinforced concrete columns with or without steel corrosion and to evaluate the effect of using CFRP wraps on the seismic behavior of the columns. Eleven identical rectangular reinforced concrete columns were constructed and tested under standard cyclic loads with variable drift amplitudes or low-cycle fatigue loads at different constant drift amplitudes. The column models included five un-corroded columns and six columns corroded using an external current method. Test results indicate that steel corrosion reduces the strength, ductility, low-cycle fatigue life, and cumulative energy dissipation capacity of reinforced concrete columns under cyclic loads, whereas the use of CFRP wraps greatly improves the above-mentioned behavior except the strength of un-corroded and corroded columns. The corroded column with a steel corrosion level of about 10% and retrofitted using CFRP wraps exhibited lower loading capacity but much better ductility and cumulative energy dissipation capacity than un-corroded columns. The seismic damage indexes of the columns with or without steel corrosion were also estimated based on the Park–Ang damage model and the relationships between damage indexes and experimental observations were discussed.

A rapid, sensitive and selective ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was developed and validated for the determination and pharmacokinetic investigation of cephalomannine in rat plasma. Sample preparation was accomplished through a simple one-step deproteinization procedure with 0.2 mL of perchloric acid-methanol (1:9, v/v) to a 0.1 mL plasma sample. Plasma samples were separated by UPLC on an Acquity UPLC BEH C18 column using a mobile phase consisting of acetonitrile-0.1% formic acid in water with gradient elution. The total run time was 2.0 min and the elution of cephalomannine was at 1.60 min. The detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction-monitoring (MRM) mode using the respective transitions m/z 832.8→264.1 for cephalomannine and m/z 812.6→286.0 for 10-DAT (internal standard), respectively. The calibration curve was linear over the range of 10-2,000 ng/mL with a lower limit of quantitation (LLOQ) of 10 ng/mL. Mean recovery of cephalomannine in plasma was in the range of 80.9-85.3%. Intra-day and inter-day precision were both

The total synthesis of emericellamides A and B is reported. A convergent, flexible strategy employing peptide chemistry, asymmetric alkylations, and culminating in macrolactamization is described. The previously reported structure of both compounds is confirmed.

While there are a number of structurally non-redundant datasets of protein monomers, there is none of protein-protein interfaces. Yet, the availability of such a dataset is expected to provide an added insight into a number of investigations. First and foremost among these is analyzing the interfaces to obtain their prevailing architectures, the forces that account for the protein-protein associations and their packing considerations. Their comparisons with those of the monomers are likely to shed additional light on protein-protein recognition on the one hand and on the folding of the polypeptide chain on the other. Docking simulations are also expected to benefit from the existence of such a dataset. A major stumbling block to the generation of a dataset of interfaces has been that the interface is composed of at least two chains. Furthermore, in the interfaces, each of the chains might be represented by non-contiguous pieces. Their order in the interfaces being compared might be different as well. This discontinuity stems from the definition of an interface. An interface consists of interacting residues between the chains, and those that are in their vicinity in the supporting scaffold, within a certain distance threshold. This necessarily yields unordered fragments, as well as isolated residues. Our novel, efficient, sequence-order-independent structural comparison technique is ideally suited to handle the task of the generation of a library of structurally non-redundant protein-protein interfaces. As it is computer-vision based, it views atoms as collections of points in space, disregarding their chain connectivity. In this work, 351 interface-families are created. Comparisons of the interfaces, and separately, of the chains which contribute to them, yield some interesting cases. In one of the cases, while two interfaces are similar, the structure of only one of the two chains is similar between the two complexes. The structure of the second chain of the first complex differs from that of the second chain of the second complex. Here the structure of the cleft in the first chain dictates the specific binding interactions. In another case, while the interfaces in the two complexes are similar, both chains composing them differ between the complexes. Lastly, the chains composing the complexes are similar, but the interfaces are dissimilar, providing a set of data for investigations of the favorable orientations of protein-protein associations.

Four-helix bundles are identified and characterized in the subunit interfaces of protein multimers. We find that this motif occurs as often in the interfaces as in the protein monomers. Common and different characteristics demonstrated by the bundles in the two environments suggest the possible stabilization mechanisms of the bundles via cooperative helical twist, dipole alignment and interhelical connections. Nucleation of parallel helix pairs may be a favourable pathway before the pairs couple into bundles during folding. Certain properties found chaotic in the interface four-helix bundles indicate that either the subunit association is far from the global minimum conformation, or that the footprints of the folding pathway are recorded in these properties.

Given a nascent protein sequence, how can one predict its signal peptide or “Zipcode” sequence? This is an important problem for scientists to use signal peptides as a vehicle to find new drugs or to reprogram cells for gene therapy (see, e.g. [7] K.C. Chou, Current Protein and Peptide Science 2002;3:615–22). In this paper, support vector machines (SVMs), a new machine learning method, is applied to approach this problem. The overall rate of correct prediction for 1939 secretary proteins and 1440 nonsecretary proteins was over 91%. It has not escaped our attention that the new method may also serve as a useful tool for further investigating many unclear details regarding the molecular mechanism of the ZIP code protein-sorting system in cells.