[Prokaryotic Expression and Bioinformatic Analysis of Rv3432c From Mycobacterium tuberculosis]. / ç»“æ ¸åˆ†æžæ†èŒRv3432cè›‹ç™½çš„åŽŸæ ¸è¡¨è¾¾ä¸Žç”Ÿç‰©ä¿¡æ¯å­¦åˆ†æž.

Objective: To express the protein enconded by the Rv3432c gene of Mycobacterium tuberculosis (M.tb) in vitro by prokaryotic expression, to analyze the structure of the Rv3432c protein by using bioinformatics software, and to explore for new drug targets against M.tb. Methods: The Rv3432c gene was amplified by PCR using the genomic DNA of the inactivated M.tb strain H37Rv as the template and a recombinant plasmid was constructed with the expression vector pET-28a. The expression products were analyzed by SDS-PAGE and purified using affinity chromatography. The biological properties of Rv3432c were analyzed with Protparam, the Pfam online tool, SOMPA, Protscale, TMHMM Signalp 6.0, NetPhos3.1, SUMOsp 2.0, and SWISS-MODEL. Results: pET-28a-Rv3432c recombinant plasmid sequencing results were fully consistent with those of the target gene. SDS-PAGE analysis showed that the fusion protein existed in the form of a soluble protein with a relative molecular mass of about 55×103, which matched the expected size. ProtParam analysis showed that the Rv3432c protein was hydrophilic (showing a GRAVY value of －0.079). Rv3432c was a protein with no transmembrane structural domains or signal peptide. The secondary structure of Rv3432c mainly consisted of random coils (39.78%) and α-helix (39.57%) and was relatively loosely structured. Conclusion: We successfully constructed a prokaryotic expression plasmid of the Rv3432c protein and analyzed its structure using bioinformatics, laying the foundation for further research on the role of Rv3432c in the pathogenesis and progression of tuberculosis as well as the identification of new drug targets against M.tb.

A new model to accurately measure the radon exhalation rate from soil using AlphaGUARD.

Radon exhalation rate from soil is a critical factor in evaluating environmental radon levels. However, AlphaGUARD PQ2000PRO may have some sensitivity towards thoron, which can have a significant impact on radon measurement. The traditional radon exhalation models generally ignore the presence of thoron, leading to an overestimation of the radon exhalation rate from soil. To handle this issue, a new model was proposed based on an analysis of several previous studies on radon exhalation theories. To prove the feasibility of the model, the radon exhalation rate measurements were performed by two different types of detectors-AlphaGUARD PQ2000PRO and RAD7. The radon exhalation rate obtained by using the new model is in good agreement with that obtained by using the theoretical model of radon exhalation of RAD7 within one standard error. This new model can be applied to accurately measure radon exhalation rate from soil by the PIC detector (PQ2000PRO).

Design of intermittent continuous measurement of radon concentration in water.

The U.S. Environmental Protection Agency established the maximum contaminant level limit for radon concentration in drinking water as 11.1 Bq L-1. A new device based on the bubbling method with a 290 mL sample bottle was designed for intermittent continuous measurement of water radon concentration. A STM32 is used to control the switch of the water pump and the valves. The Water-Radon-Measurement software written in C# is to connect RAD7 and calculate the water radon concentration automatically.

Type I Photosensitizer Targeting G-Quadruplex RNA Elicits Augmented Immunity for Cancer Ablation.

Type I photodynamic therapy (PDT) represents a promising treatment modality for tumors with intrinsic hypoxia. However, type I photosensitizers (PSs), especially ones with near infrared (NIR) absorption, are limited and their efficacy needs improvement via new targeting tactics. We develop a NIR type I PS by engineering acridinium derived donor-π-acceptor systems. The PS exhibits an exclusive type I PDT mechanism due to effective intersystem crossing and disfavored energy transfer to O2 , and shows selective binding to G-quadruplexes (G4s) via hydrogen bonds identified by a molecular docking study. Moreover, it enables fluorogenic detection of G4s and efficient O2 ⋅- production in hypoxic conditions, leading to immunogenic cell death and substantial variations of gene expression in RNA sequencing. Our strategy demonstrates augmented antitumor immunity for effective ablation of immunogenic cold tumor, highlighting its potential of RNA-targeted type I PDT in precision cancer therapy.

COMPARISON OF RADON EXHALATION RATE MEASUREMENTS ON REFERENCE DEVICE IN OPEN AND CLOSED LOOP BY ALPHAGUARD IN FLOW-THROUGH MODE.

Radon-222 (Rn-222) exhalation rate is vital for estimating radiation risk from many kinds of materials. AlphaGUARD measures the radon concentration based on the ionization chamber principle, which is currently recognized as a reference instrument to measure radon. In China, measurements of radon exhalation rate are performed by AlphaGUARD operated in flow-through mode on a reference device to verify measurement accuracy. These measurements are performed in both open and closed loop. AlphaGUARD can fast rapidly the variation of the radon concentration in the chamber, which is tightly pressed against the surface of the medium to accumulate the exhaled radon. When the model is used to obtain the radon exhalation rate, the radon exhalation rates obtained by nonlinear data fitting on the measured radon concentrations are similar to the reference value of the device. The difference of radon exhalation rate values of six measurements is small.

Atmospheric electrostatic induction on carrier transfer in volumetric photoelectrochemical system with MXene-modified electrodes.

With WO3/BiVO4/MXene ternary composite layers as a working electrode, a smart volumetric photoelectrochemical system using electrostatic bias voltage inducted by atmospheric electric field was developed. Under single sun illumination and 0.8 V hardwired bias, the current response of the ternary electrode is 1.15 mA cm-2, which is 1.31 times higher than that of the WO3/BiVO4 electrode, mainly due to the higher charge transfer rate between the MXene layer and the BiVO4 structure. Further, the response of the ternary electrode increases to 1.39 mA cm-2 at an extra atmospheric electric field of 1100 V m-1. It can be demonstrated that the effect of the atmospheric electric field can be regarded as an extra hardwired bias of 0.101 V in the system. The experimental results reveal that the native carriers, including inducted electron/holes in MXene and BiVO4, and carriers in the electrolyte, are all effectively excited by the electrostatic induction of atmospheric electric field.

Investigation of 3-year inpatient TB cases in Zunyi, China: Increased TB burden but improved bacteriological diagnosis.

Background: As one of the top three high tuberculosis (TB) burden countries, China is a country where the overall TB incidence continues to decline. However, due to its large population and area, the increased TB burden exists in regional areas. Methods: This retrospective study analyzed local inpatient pulmonary TB cases in the Affiliated Hospital of Zunyi Medical University (AHZMU) from January 2016 to December 2018 in a high TB incidence and economically-less-developed area of China. Four methods, acid-fast bacilli stain, culture, Xpert and LAMP, were used to detect Mycobacterium tuberculosis (M.tb), while proportional method and Xpert were used to identify rifampicin-resistant TB (RR-TB). Case number, treatment history, M.tb confirmed TB and rifampicin resistant proportion were analyzed to investigate the local TB epidemic. Results: Total 3,910 local inpatient cases with pulmonary TB were admitted to AHZMU during this study period. The annual numbers of total TB cases increased 26.4% (from 1,173 to 1,483), while new cases increased 29.6% (from 936 to 1,213) and RR-TB cases increased 2.7 times (from 31 to 84). Meanwhile, the percentage of previously treated cases declined from 20.2 to 18.2% and the M.tb confirmed TB proportion increased from 34.7 to 49.7%. Conclusion: The elevated M.tb confirmed TB proportion and the declined percentage of previously treated cases indicated the improved TB diagnosis and treatment of AHZMU. However, the increasing number of total TB cases, new and RR-TB cases showed an upward trend and increased TB burden in a relatively underdeveloped area of China.

Jiella sonneratiae sp. nov., a novel endophytic bacterium isolated from bark of Sonneratia apetala.

A new endophytic bacterium, designated strain MQZ13P-4T was isolated from Sonneratia apetala collected from Maowei sea Mangrove Nature Reserve in Guangxi Zhuang Autonomous Region, PR China. The 16S rRNA gene sequence similarity between strain MQZ13P-4T and its closest phylogenetic neighbour Jiella endophytica CBS5Q-3T was 97.9 %. Phylogenetic analyses using 16S rRNA gene sequences and whole-genome sequences showed that strain MQZ13P-4T formed a distinct lineage with Jiella endophytica CBS5Q-3T, Jiella pacifica 40Bstr34T and Jiella aquimaris JCM 30119T. The draft genome of strain MQZ13P-4T was 5 153 243 bp in size and its DNA G+C content was 68.1 mol%. Comparative genome analysis revealed that the average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values among strain MQZ13P-4T and other related species were below the cut-off levels of 95, 70 and 95.5 %, respectively. The cell-wall peptidoglycan of strain MQZ13P-4T contained meso-diaminopimelic acid as the diagnostic diamino acid. The respiratory quinone was Q-10. The major cellular fatty acid was C18 : 1 ω7c. The polar lipids comprised phosphatidylcholine, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, two unidentified aminolipids and two unidentified lipids. Strain MQZ13P-4T had a typical chemical compositions of fatty acids, lipids, quinones and diagnostic diamino acid for Jiella species, but could be distinguished from known species of the genus Jiella. Based on polyphasic evidence, strain MQZ13P-4T represents novel species of the genus Jiella, for which the name Jiella sonneratiae sp. nov. is proposed. The type strain is MQZ13P-4T (=CGMCC 1.18727T=JCM 34333T).

Li+ Selectivity of Carboxylate Graphene Nanopores Inspired by Electric Field and Nanoconfinement.

The regulation of the ion selectivity by electric field and ion association on the Li+ selectivity of carboxyl functionalized graphene nanopores are investigated by molecular dynamics simulation. Carboxylate graphene nanopores of sub-2 nm exhibit excellent Li+ selectivity under the electric field of 1.0 V nm-1 . The results show that ion association inspired by electric field may be a key factor affecting ion selectivity of sub-2 nm nanopores. The ion association of Mg2+ and Cl- can be promoted obviously near the nanopores under the electric field of 1.0 V nm-1 . The migrating of Mg2+ can be retarded by stable clusters of Mg2+ and Cl- formed near nanopores. The degree of association of Li+ with Cl- is relatively low and the disassociation of the Li+ cluster is easier so that Li+ can more easily pass through the nanopores. These results gain insight into the effect of ion association inspired by electric field and nanoconfinement of graphene nanopore on Mg2+ /Li+ separation, and provide helpful information for the application of nanoporous materials in extraction of Li+ ion from salt-lake brine.

A four-electron Zn-I2 aqueous battery enabled by reversible I-/I2/I+ conversion.

Electrochemically reversible redox couples that embrace more electron transfer at a higher potential are the eternal target for energy storage batteries. Here, we report a four-electron aqueous zinc-iodine battery by activating the highly reversible I2/I+ couple (1.83 V vs. Zn/Zn2+) in addition to the typical I-/I2 couple (1.29 V). This is achieved by intensive solvation of the aqueous electrolyte to yield ICl inter-halogens and to suspend its hydrolysis. Experimental characterization and modelling reveal that limited water activity and sufficient free chloride ions in the electrolyte are crucial for the four-electron process. The merits of the electrolyte also afford to stabilize Zn anode, leading to a reliable Zn-I2 aqueous battery of 6000 cycles. Owing to high operational voltage and capacity, energy density up to 750 Wh kg-1 based on iodine mass was achieved (15-20 wt% iodine in electrode). It pushes the Zn-I2 battery to a superior level among these available aqueous batteries.

[Effects of Enterovirus 71 on Mitochondrial Dynamics in Human Glioma U251 Cells].

OBJECTIVE: To investigate the effects of enterovirus 71 (EV71) on mitochondrial dynamics in human Glioma U251 cells. METHODS: The EV71 was replicated in Vero cells and the 50% tissue culture infective dose (TCID 50) was calculated based on the Reed-Muench formula. After the U251 cells were infected with EV71, the cellular morphology was assessed through the light microscope. The mitochondrial morphology was detected by MitoTracker Deep Red staining under laser confocal microscopy and the mitochondrial ultrastructure was visualized by transmission electron microscopy. The expressions of mitochondrial fission proteins Drp1, p-Drp1 and fusion protein Opa1 were examined by Western blot. The level of ATP was measured by a commercial ATP assay kit. The generation of mitochondrial superoxide was detected by MitoSOX staining. RESULTS: The TCID 50 of EV71 was 10 －5.4/0.1 mL. Twenty-four or 48 h after EV71 infection, the U251 cells appeared shrunken, round and dead. The laser confocal microscopy and transmission electron microscopy images showed that the EV71 infection induced mitochondrial elongation and cristae damage. Moreover, Western blot analysis demonstrated that the protein expressions of Drp1 and Opa1 were downregulated at both 24 and 48 h after EV71 infection in U251 cells, companied with a significant increase in Drp1 phosphorylation at 48 h after infection ( P<0.05). In addition, a decreased ATP level and elevated mitochondrial superoxide generation were observed in the EV71 infected group, as compared to the control group. CONCLUSION: Our study demonstrated that infection with EV71 led to changes of mitochondrial morphology and dynamics in U251 cells, which may impair mitochondrial function and contribute to nervous system dysfunction.

A Rainbow-Based Authentical Scheme for Securing Smart Connected Health Systems.

Smart Connected Health Systems (SCHSs) belong to health systems that provide services of health care remotely. They provide the doctors with access to electronic medical records with the aid of medical sensors, smart wearable devices and smart medical instruments. Although SCHSs have many applications in the area of health care, securing massive amount of valuable and sensitive data of the patients and preserving the privacy are challenging. User authentication based on public key cryptographic techniques is playing a crucial role in SCHSs for protecting the privacy of patients. However, quantum computers will break such techniques. Rainbow signature is one of the candidates of the next generation of cryptographic algorithms which can resist attacks on quantum computers. However, it is vulnerable to Differential Power Analysis (DPA) attacks, which is based on information gained from the cryptographic implementations. We present techniques to exploit the countermeasures to protect Rainbow against DPA attacks. We propose a variant of Rainbow with resistance to DPA attacks. First, we take a random vector to randomize the power consumption of private keys during computing the first affine transformation; Second, random variables are adopted during computing central map transformation; Third, we take two random vectors during computing the second affine transformation to randomize the power consumption of private keys. We analyze the efficiency and implement the scheme on hardware. Compared with the related implementations, our scheme is efficient and suitable for signature generations on hardware. Besides, we propose a secure authentical scheme based on the implementation for protecting record of patients in SCHSs.

Interaction-Transferable Graphene-Isolated Superstable AuCo Nanocrystal-Enabled Direct Cyanide Capture.

Noble metals with strong plasmons have been widely used as enhancement substrates for molecule identification. However, cyanide, a toxic and important signaling molecule with a corrosive nature to noble metals, makes direct recognition challenging. Herein a novel superstable magnetic graphene-isolated AuCo nanocrystal (MACG) has been designed. Such graphene isolation enables superior stability without corrosion. Moreover, unexpectedly, although graphene isolated direct contact between Au and cyanide, their interaction was transferable and remained, which gifted MACGs direct cyanide capture capability with no specific ligands needed. Density functional theory calculations and natural bond orbital analysis indicated that the graphene isolation only slightly affected the charge transfer and that a relatively strong interaction was maintained between Au and cyanide. MACGs were utilized for efficient cyanide capture and clearance in various hydrologic environments and sensitive in vivo cyanide capture in C. elegans infected with P. aeruginosa, a pathogen with cyanide as the biomarker, indicating promise for various applications.

Design, synthesis and fungicidal activity evaluation of novel pyrimidinamine derivatives containing phenyl-thiazole/oxazole moiety.

Diflumetorim is a member of pyrimidinamine fungicides that possess excellent antifungal activities. Nevertheless, as reported that the activity of diflumetorim to corn rust (Puccinia sorghi) was not ideal (EC50 = 53.26 mg/L). Herein, a series of novel pyrimidinamine derivatives containing phenyl-thiazole/oxazole moiety were designed based on our previous study and the structural characteristics of diflumetorim, synthesized and bioassayed to discover novel fungicides with excellent antifungal activities. Among these compounds, T18 gave the optimal fungicidal activity, which respectively offers control effects with EC50 values of 0.93 mg/L against P. sorghi and 1.24 mg/L against E. graminis, significantly superior to commercial fungicides diflumetorim, tebuconazole, and flusilazole. Cell cytotoxicity results suggested that compound T18 has lower toxicities than diflumetorim. Furthermore, DFT calculation indicated that the phenyl-thiazole/oxazole moiety plays an unarguable role in the improvement of activity, which will contribute to designing and developing more potent compounds in the future.

Lighting up the Native Viral RNA Genome with a Fluorogenic Probe for the Live-Cell Visualization of Virus Infection.

RNA viruses represent a major global health threat, and the visualization of their RNA genome in infected cells is essential for virological research and clinical diagnosis. Due to the lack of chemical toolkits for the live-cell imaging of viral RNA genomes, especially native viral genomes without labeling and genetic modification, studies on native virus infection at the single-live-cell level are challenging. Herein, taking hepatitis C virus (HCV) as a representative RNA virus, we propose that the innate noncanonical G-quadruplex (G4) structure of viral RNA can serve as a specific imaging target and report a new benzothiazole-based G4-targeted fluorescence light-up probe, ThT-NE, for the direct visualization of the native RNA genome of HCV in living host cells. We demonstrate the use of the ThT-NE probe for several previously intractable applications, including the sensitive detection of individual virus-infected cells by small-molecule staining, real-time monitoring of the subcellular distribution of the viral RNA genome in live cells, and continuous live-cell tracking of the infection and propagation of clinically isolated native HCV. The fluorogenic-probe-based viral RNA light-up system opens up a promising chemical strategy for cutting-edge live-cell viral analysis, providing a potentially powerful tool for viral biology, medical diagnosis, and drug development.

Nature of Monomeric Molybdenum(VI) Cations in Acid Solutions Using Theoretical Calculations and Raman Spectroscopy.

The composition and structures of the two protonated species formed from uncharged molybdic acid, MoO2(OH)2(OH2)20, in strongly acidic solutions have been investigated using a combination of density functional theory calculations, first-principles molecular dynamics simulations, and Raman spectroscopy. The calculations show that both protonated species maintain the original octahedral structure of molybdic acid. Computed p Ka values indicated that the ═O moieties are the proton acceptor sites and, therefore, that MoO(OH)3(OH2)2+ and Mo(OH)4(OH2)22+ are the probable protonated forms of Mo(VI) in strong acid solutions, rather than the previously accepted MoO2(OH)2- x(OH2)2+ x x+ ( x = 1, 2) species. This finding is shown to be broadly consistent with the observed Raman spectra. Structural details of MoO(OH)3(OH2)2+ and Mo(OH)4(OH2)22+ are reported.

Engineering an NIR rhodol derivative with spirocyclic ring-opening activation for high-contrast photoacoustic imaging.

Molecular probes that enable high-contrast photoacoustic (PA) imaging of cellular processes are valuable tools for in vivo studies. Design of activatable PA probes with high contrast remains elusive. We develop a new NIR rhodol derivative, Rhodol-NIR, with a large extinction coefficient, low quantum yield and structural switching from a 'ring-open' form to a 'closed' spirolactone upon esterification. This structural transition, together with the ideal photophysical properties, enables the development of activatable probes for high-contrast PA imaging via a target-specific de-esterification reaction. This strategy is demonstrated using a PA probe designed for a tumor biomarker, human NAD(P)H: quinone oxidoreductase isozyme 1 (hNQO1), which affords high contrast and excellent sensitivity for PA detection and imaging of hNQO1 in living cells and animals. The strategy can provide a new paradigm for engineering activatable PA probes for high-contrast imaging.

Cas1 and Cas2 From the Type II-C CRISPR-Cas System of Riemerella anatipestifer Are Required for Spacer Acquisition.

Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins provide acquired genetic immunity against the entry of mobile genetic elements (MGEs). The immune defense provided by various subtypes of the CRISPR-Cas system has been confirmed and is closely associated with the formation of immunological memory in CRISPR arrays, called CRISPR adaptation or spacer acquisition. However, whether type II-C CRISPR-Cas systems are also involved in spacer acquisition remains largely unknown. This study explores and provides some definitive evidence regarding spacer acquisition of the type II-C CRISPR-Cas system from Riemerella anatipestifer (RA) CH-2 (RA-CH-2). Firstly, introducing an exogenous plasmid into RA-CH-2 triggered spacer acquisition of RA CRISPR-Cas system, and the acquisition of new spacers led to plasmid instability in RA-CH-2. Furthermore, deletion of cas1 or cas2 of RA-CH-2 abrogated spacer acquisition and subsequently stabilized the exogenous plasmid, suggesting that both Cas1 and Cas2 are required for spacer acquisition of RA-CH-2 CRISPR-Cas system, consistent with the reported role of Cas1 and Cas2 in type I-E and II-A systems. Finally, assays for studying Cas1 nuclease activity and the interaction of Cas1 with Cas2 contributed to a better understanding of the adaptation mechanism of RA CRISPR-Cas system. This is the first experimental identification of the naïve adaptation of type II-C CRISPR-Cas system.

ATPase activity of GroEL is dependent on GroES and it is response for environmental stress in Riemerella anatipestifer.

Riemerella anatipestifer (Ra) is a serious gram-negative pathogen of birds and can cause considerable economic losses. The survival mechanisms of R. anatipestifer in the host and environment remain largely unknown. Previous results have demonstrated that GroEL is a molecular chaperone and an important component of the response to various stresses in most bacteria. This study focused on whether GroEL is implicated in this process in R. anatipestifer. The 1629 bp groEL is highly conserved among other gram-negative bacteria (levels of sequence similarity > 60%). A structural analysis and ATPase activity assay revealed that RaGroEL had weak ATPase activity and that the enzyme activity was temperature and ion dependent. GroES partially enhanced the GroEL ATPase activity in the same temperature range. In addition, we studied the mRNA expression of groEL under abiotic stresses caused by heat shock, pH, salt and hydrogen peroxide. These stresses increased the transcription of groEL to varying degrees. In R. anatipestifer, the ATPase activity of GroEL is dependent on GroES and temperature. The expression of groEL was strongly induced by heat, pH, hydrogen peroxide and salt stress. This study is the first to show that GroEL in R. anatipestifer might play a major role in response to environmental stress.