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Asymmetric Os(ii)/Ru(ii) dinuclear complexes exhibit photo-induced intramolecular energy transfer from the Ru-based higher-energy 3MLCT state to that of the Os-based unit at lower energy.

Pathogen virulence is largely driven by the evolution and adaptation of the genome. LasR is a master regulator of quorum-sensing (QS) system. The QS-inactive LasR-null mutant regains QS activation in a laboratory evolution experiment through obtaining mutations inmexT, a gene encoding transcriptional regulator. How the QS-active LasR-MexT mutant continuously evolves is still unknown. Here we passaged the LasR-MexT mutant in casein broth and monitored its evolutionary trajectory. By examining the proteolytic phenotype of isolated single colonies, we found a protease-negative subpopulation arising from the parental population. The whole genome sequencing analysis revealed that these protease-negativ colonies bear mutations inpilDgene. In accordance with its role as a prepilin peptidase of type IV system, PilD mutants are defective in twitching motility. In conclusion, we identified a new PilD mutant cheater that evolved from the parental LasR-MexT mutant population. Our work demonstrates that population evolution is highly dynamics, with arising of distinct subpopulations containing different social behaviors.

LasR is a master regulator of quorum-sensing (QS) inPseudomonas aeruginosa. LasR-null mutants commonly appear in lung isolates from chronically infected cystic fibrosis (CF) patients. However, numerous such CF isolates have a QS-active phenotype, but factors underlying QS-reprogramming in LasR-null mutants remain largely unknown. Mutations in the transcriptional regulator genemexTare well known to be responsible for QS-reprogramming in a laboratory LasR-null mutant strain, however, simultaneous occurrence oflasRandmexTmutations is rare in CF isolates. To identify QS-reprogramming determinants, we developed an experimental evolution approach, for which a QS-inactive LasR null mutant with an extra copy ofmexTwas engineered. In such a strain, spontaneous singlemextTmutations are expected to have no or little phenotypic consequences. This novel method, named “targeted gene duplication followed by mutant screening” (TGD-MS), resulted in identification of QS-active revertants with mutations in genes other thanmexT. We characterized a QS-active revertant with a point mutation inrpoA, a gene encoding the α-subunit of RNA polymerase. QS activation in this mutant was found to be associated with down-regulated expression ofmexEF-oprNefflux pump genes. In an iterative TGD-MS experiment, we discovered mutations inmexE, a gene encoding a membrane fusion protein of the MexEF-OprN efflux pump. Our results implicate that a regulatory circuit controlling the expression of themexEF-oprNoperon is critical for QS-reprogramming. In conclusion, our study reports on identification of non-MexT proteins associated with QS-reprogramming in a laboratory strain, shedding light on possible QS activation mechanisms in clinicalP. aeruginosaisolates. More generally, we describe a novel experimental evolution approach, in which the populations contain extra copies of previously identified genes. The TGD-MS method facilitates the identification of mutations in unknown genes and opens the perspective of iterative application. We suggest that this method can be employed to uncover untapped pathways in any transformable haploid organism.

The revised Provisions for Drug Registration was promulgated by the State Administration for Market Regulation of China in March 2020 and came into force on July 1, 2020. This article describes the history of the drug registration management system in China, explains the background of the revision of the Provisions for Drug Registration in 2020, and introduces the main modifications of the Provisions for Drug Registration in 2020 in the aspects of registration classification, application for clinical trial on drug, application for drug marketing authorization, accelerated procedure for drug registration, working timeline, and supervision and administration. This article is intended to give a brief overview for those who wish to submit a drug registration application in China or for those who would like to get more acquainted with drug registration in China.

We develop a biotin-based tandem labeling approach to improve detection sensitivity of DNA probe. Through DNA polymerase-mediated overhand filling, the 3'end of DNA probe was tandemly labeled with biotin molecules. The intensity of biotin signals could be flexibly manipulated by controlling the introduced length of poly(A) in the 5' overhang.

Flooding is becoming a prominent issue in coastal cities, flood forecasting is the key to solving this problem. However, the lack and imbalance of research data and the insufficient performance of the model have led to the complexity and uncontrollability of flood forecasting. To forecast coastal floods accurately and reliably, the Internet of Things technology is used to collect data on floods and flood factors in smart cities. An ensemble learning method based on Bayesian model combination (BMC-EL) is designed to predict flood depth. First, flood intensity classification and K-fold cross-validation are introduced to generate multiple training subsets from the training set to realize uniform sampling and increase the diversity of subsets. Second, the backpropagation neural network (BPNN) and random forest (RF) are used as the base learners to build the prediction model and then import it into training subsets for training purposes. Finally, based on the prediction performance of the base learner in the validation sets, the Bayesian model combination strategy is formulated to integrate and output predicted values. We describe experiments conducted to forecast flood depth 1 h in advance that several machine learning models were trained and tested using real flood data taken from Macao, China. The models include linear regression, support vector machine, BPNN, RF and BMC-EL models. Results prove the accuracy and reliability of the BMC-EL method in flood forecasting for coastal cities.

Quorum sensing (QS) is a microbial cell–cell communication mechanism and plays an important role in bacterial infections. QS-mediated bacterial infections can be blocked through quorum quenching (QQ), which hampers signal accumulation, recognition, and communication. The pathogenicity of numerous bacteria, including Xanthomonas campestris pv. campestris (Xcc), is regulated by diffusible signal factor (DSF), a well-known fatty acid signaling molecule of QS. Cupriavidus pinatubonensis HN-2 could substantially attenuate the infection of XCC through QQ by degrading DSF. The QQ mechanism in strain HN-2, on the other hand, is yet to be known. To understand the molecular mechanism of QQ in strain HN-2, we used whole-genome sequencing and comparative genomics studies. We discovered that the fadT gene encodes acyl-CoA dehydrogenase as a novel QQ enzyme. The results of site-directed mutagenesis demonstrated the requirement of fadT gene for DSF degradation in strain HN-2. Purified FadT exhibited high enzymatic activity and outstanding stability over a broad pH and temperature range with maximal activity at pH 7.0 and 35 °C. No cofactors were required for FadT enzyme activity. The enzyme showed a strong ability to degrade DSF. Furthermore, the expression of fadT in Xcc results in a significant reduction in the pathogenicity in host plants, such as Chinese cabbage, radish, and pakchoi. Taken together, our results identified a novel DSF-degrading enzyme, FadT, in C. pinatubonensis HN-2, which suggests its potential use in the biological control of DSF-mediated pathogens.

Bradyrhizobium diazoefficiens USDA110 is one of the most effective nitrogen-fixing symbionts of soybeans. Here we carried out a large-scale transposon insertion sequencing (Tn-seq) analysis of strain Bd110spc4, which is derived from USDA110, with the goal of increasing available resources for identifying genes crucial for the survival of this plant symbiont under diverse conditions. We prepared two transposon (Tn) insertion libraries of Bd110spc4 with 155,042 unique Tn insertions when the libraries were combined, which is an average of one insertion every 58.7 bp of the reference USDA110 genome. Application of bioinformatic filtering steps to remove genes too small to be expected to have Tn insertions, resulted in a list of genes that were classified as putatively essential. Comparison of this gene set with genes putatively essential for the growth of the closely related alpha-proteobacterium, Rhodopseudomonas palustris, revealed a small set of five genes that may be collectively essential for closely related members of the family Bradyrhizobiaceae. This group includes bacteria with diverse lifestyles ranging from plant symbionts to animal-associated species to free-living species.

Growing evidence has suggested that abnormally expressed long non-coding RNAs (lncRNAs) play critical regulatory roles in nasopharyngeal carcinoma (NPC) pathogenesis. Family with sequence similarity 225 member B (FAM225B) is a novel lncRNA that has been implicated in several human cancers, yet its role in the context of NPC remains largely unclear. The aim of this study was to determine the expression level of FAM225B and its clinical significance in NPC patients. We observed a remarkable increase of FAM225B in NPC tissues and cell lines compared with controls. Also, highly expressed FAM225B was closely correlated with advanced TNM stage, distant metastasis, and poor overall survival. Interestingly, loss-of-function analysis revealed that FAM225B knockdown significantly inhibited tumor growth in vitro and in vivo, and decreased the migratory and invasive capacity of NPC cells. Mechanically, FAM225B functioned as an endogenous sponge by competing for miR-613 binding to up-regulate CCND2 expression. More importantly, rescue experiments further demonstrated that the suppressive impacts of FAM225B knockdown on cell proliferation, migration and invasion were significantly reversed after CCND2 overexpression. Taken all together, these findings highlight FAM225B as an oncogene that promotes NPC proliferation and metastasis through miR-613/CCND2 axis.

Many Gram-negative bacteria communicate by using homoserine lactones (HSLs) as quorum sensing (QS) signals in a cell density-dependent manner. In addition to fatty acyl-HSL (acyl-HSL) signals, certain strains, most of them associated with plants, produce non-canonical aryl-HSLs such as cinnamoyl-HSL. However, the role of aryl-HSL in endophytic associations remained elusive. Bradyrhizobium sp. strain ORS278 possesses a LuxI-LuxR type QS system and produces cinnamoyl-HSL as a QS signal. Here, we report that strain ORS278 promotes growth of domesticated rice (Oryza sativa). QS mutants unable to produce cinnamoyl-HSL exhibited reduced plant-growth promoting activity in comparison to the parent strain ORS278. Likewise, the QS mutants were impaired in their ability to colonize rice roots. These findings suggest that genes controlled by cinnamoyl-HSL play an important role in the association between rice and ORS278. However, biofilm production was not visibly altered in these mutants. In conclusion, our study highlights the importance of aryl-HSLs in endophytic plant-bacteria interactions.

Background Nasopharyngeal carcinoma (NPC) is the most common type of head and neck cancers which is notable for its distinctive pattern of geographical distribution. HOTAIR has been reported to regulate nasopharyngeal carcinoma tumorigenesis and progression. However, the detailed mechanism underlying HOTAIR-promoted nasopharyngeal carcinoma remains not fully understood. Methods We used RT-qPCR approach to examine genes expression and mRNA level. MTT assay and soft agar assay were used to detect cell growth rate in culture and under suspended condition, respectively. Besides, we employed wound healing assay and transwell invasion assay to determine migration and invasion ability of nasopharyngeal carcinoma cells. We predicted direct downstream targets of miR-101 by bioinformatic analysis, which was confirmed by dual luciferase reporter assay. Results HOTAIR was upregulated in NPC tissues and cells. miR-101 inhibitor greatly enhanced HOTAIR knockdown-regulated cell proliferation, migration and invasion of CNE1 and CNE2 cells. miR-101 was shown to directly bind 3′-UTR of COX-2 and downregulate COX-2 expression. Finally, COX-2 overexpression was demonstrated to rescue the tumor phenotypes of nasopharyngeal carcinoma cells attenuated by HOTAIR knockdown or miR-101 mimic. Conclusions Here, we highlight the importance of HOTAIR/miR-101/COX-2 axis in progression of nasopharyngeal carcinoma cells. Our findings provide a novel mechanism for explaining HOTAIR-induced nasopharyngeal carcinoma and help developing the therapeutical strategies by targeting HOTAIR.

Pseudomonas aeruginosa is an opportunistic pathogen with high clinical relevance for hospital infections of patients. Accumulating DNA sequencing results of clinical P. aeruginosa isolates have revealed frequent mutations in lasR gene, which encodes the highest arches component of quorum-sensing system (QS). We analyzed the sequencing data of lasR gene from a large collection of cystic fibrosis (CF) P. aeruginosa isolates. Our systematical analyses revealed that single nucleotide polymorphisms (SNPs) selection in lasR gene were largely constrained by codon-usage frequency. As a whole, SNP-substituted codons encoding unconserved amino acid resulted in unfavored codons with relatively low codon-usage frequency, while those associating with conserved amino acid were not strictly regulated in such way. These SNPs substitutions gives rise to diverse functional LasR isoforms and contributes to the relative growth fitness of recombinant lasR variant strains. Our survey reveals a novel pattern of SNPs selections in lasR gene of CF isolates. Our findings could be served as a powerful resource for understanding adaptive mechanism of clinical isolates under environmental constrains and developing anti-bacteria drugs for CF patients.

An intelligent water regime detection system was designed for water detection. In the designed system, water level is detected by a pressure sensor and water pH is detected by a pH meter. After being processed by the AD chip TLC2543, the data are sent to the MCU via serial communication and the detection result is displayed on OLED screen or Bluetooth mobile phone. The software adopts time-sharing and power-down operation modes, and combines the relay to turn on/off the MCU peripheral circuit to reduce power consumption. The measurement deviations of water level, pH, and voltage were respectively less than 2 mm, 0.1, and 0.01 V and the minimum operating current was less than 6 mA. The low-power, high-precision and intelligent water regime detection is realized by the designed system.

Climate change causes extreme weather in Macao, especially typhoons and flooding. In this paper, some raw flood data is missing from the Macao Meteorological and Geophysical Bureau, due to some flood sensors that were damaged during Typhoon Hato in 2017 and Typhoon Mangkhut in 2018. So we use data interpolation to construct new datasets and curve fitting to simulate real inundation depth. Besides this, we explore Neural Network, Long Short-Term Memory, Random Forest, Adaptive Boosting, and Linear Regression for analyzing, comparing, and evaluating the best combinations of flood prediction models, datasets, and scenarios caused by typhoon presence in Macao. Furthermore, we apply Bayes Network to the aforementioned models to evaluate the accuracy of predicting flood situations because of typhoons. The experiment results show that the different models achieve a different performance in predicting specific scenarios.

Gcn5 is a histone acetyltransferase that was previously shown to regulate phototropic and starvation-induced autophagy in the rice blast fungus Magnaporthe oryzae, likely via modification on autophagy protein Atg7. In this study, we identified more potential substrates of Gcn5-mediated acetylation by quantitative and comparative acetylome analyses. By epifluorescence microscopy and biochemistry experiments, we verified that Gcn5 may regulate autophagy induction at both the epigenetic and posttranslational levels and regulate autophagic degradation of a critical metabolic enzyme pyruvate kinase (Pk) likely via acetylation. Overall, our findings reveal comprehensive posttranslational modification executed by Gcn5, in response to various external stimuli, to synergistically promote cellular differentiation in a fungal pathogen., The rice blast fungus Magnaporthe oryzae poses a great threat to global food security. During its conidiation (asexual spore formation) and appressorium (infecting structure) formation, autophagy is induced, serving glycogen breakdown or programmed cell death function, both essential for M. oryzae pathogenicity. Recently, we identified an M. oryzae histone acetyltransferase (HAT) Gcn5 as a key regulator in phototropic induction of autophagy and asexual spore formation while serving a cellular function other than autophagy induction during M. oryzae infection. To further understand the regulatory mechanism of Gcn5 on M. oryzae pathogenicity, we set out to identify more Gcn5 substrates by comparative acetylome between the wild-type (WT) and GCN5 overexpression (OX) mutant and between OX mutant and GCN5 deletion (knockout [KO]) mutant. Our results showed that Gcn5 regulates autophagy induction and other important aspects of fungal pathogenicity, including energy metabolism, stress response, cell toxicity and death, likely via both epigenetic regulation (histone acetylation) and posttranslational modification (nonhistone protein acetylation). IMPORTANCE Gcn5 is a histone acetyltransferase that was previously shown to regulate phototropic and starvation-induced autophagy in the rice blast fungus Magnaporthe oryzae, likely via modification on autophagy protein Atg7. In this study, we identified more potential substrates of Gcn5-mediated acetylation by quantitative and comparative acetylome analyses. By epifluorescence microscopy and biochemistry experiments, we verified that Gcn5 may regulate autophagy induction at both the epigenetic and posttranslational levels and regulate autophagic degradation of a critical metabolic enzyme pyruvate kinase (Pk) likely via acetylation. Overall, our findings reveal comprehensive posttranslational modification executed by Gcn5, in response to various external stimuli, to synergistically promote cellular differentiation in a fungal pathogen.

Nervous system (NS) development relies on coherent upregulation of extensive sets of genes in a precise spatiotemporal manner. How such transcriptome-wide effects are orchestrated at the molecular level remains an open question. Here we show that 3′-untranslated regions (3′ UTRs) of multiple neural transcripts contain AU-rich cis-elements (AREs) recognized by tristetraprolin (TTP/Zfp36), an RNA-binding protein previously implicated in regulation of mRNA stability. We further demonstrate that the efficiency of ARE-dependent mRNA degradation declines in the neural lineage because of a decrease in the TTP protein expression mediated by the NS-enriched microRNA miR-9. Importantly, TTP downregulation in this context is essential for proper neuronal differentiation. On the other hand, inactivation of TTP in non-neuronal cells leads to dramatic upregulation of multiple NS-specific genes. We conclude that the newly identified miR-9/TTP circuitry limits unscheduled accumulation of neuronal mRNAs in non-neuronal cells and ensures coordinated upregulation of these transcripts in neurons., Nervous system development relies on coherent up-regulation of extensive genes in a precise spatiotemporal manner. Here, the authors show that miR-9/TTP circuitry ensures coordinated up-regulation of neuronal mRNAs in neurons and limits unscheduled accumulation of these transcripts in non-neuronal cells.

Vehicles' safety surveillances have been paid more attentions on by the governments with increasingly rampant terrorist activities like car bombing attacks and illegal immigrations. Lots of terrorists may hide the bombs under the vehicles to avoid the searches by the workers. Illegal immigrants usually adopt the same tricks. Hence, vehicles' bottom will be one of the most important searching places in the safety inspection. However, traditional bottom inspections are accomplished manually with hand-held security mirrors. This method has poor efficiency, limited searching areas, unbearable reliability and large consumption of human resources. So computer vision and intelligent transportation technologies are led into the safety inspections and surveillances according to these critical defects. Line scanned and area scanned CCD cameras are trigged by the vehicle detection apparatus to grab images of the vehicles' bottom and license plates respectively. These images will be processed by the industrial computers real-timely. Sounded alarms can remind the workers there are existing doubtable foreign goods under the bottom. The experimental results indicate preliminarily that the proposed method not only have good performances on detection rate and low false alarm rate, also can improve the reliability effectively.

RNA-binding protein HuR modulates the stability and translational efficiency of messenger RNAs (mRNAs) encoding essential components of the cellular proliferation, growth and survival pathways. Consistent with these functions, HuR levels are often elevated in cancer cells and reduced in senescent and quiescent cells. However, the molecular mechanisms that control HuR expression are poorly understood. Here we show that HuR protein autoregulates its abundance through a negative feedback loop that involves interaction of the nuclear HuR protein with a GU-rich element (GRE) overlapping with the HuR major polyadenylation signal (PAS2). An increase in the cellular HuR protein levels stimulates the expression of long HuR mRNA species containing an AU-rich element (ARE) that destabilizes the mRNAs and thus reduces the protein production output. The PAS2 read-through occurs due to a reduced recruitment of the CstF-64 subunit of the pre-mRNA cleavage stimulation factor in the presence of the GRE-bound HuR. We propose that this mechanism maintains HuR homeostasis in proliferating cells. Since only the nuclear HuR is expected to contribute to the auto-regulation, our model may explain the longstanding observation that the increase in the total HuR expression in cancer cells often correlates with the accumulation of its substantial fraction in the cytoplasm. Published version