Aims
The aim of this study was to evaluate the antagonistic activity of halotolerant bacteria against rice brown stripe pathogen Acidovorax oryzae.
Methods and Results
Fifteen of 136 isolates of ...halotolerant bacteria exhibited strong in vitro and in vivo antagonistic activity against both strains of A. oryzae. The 15 antagonistic isolates were identified as ‘operational group Bacillus amyloliquefaciens’ based on physiological and biochemical features, fatty acid profiles as well as sequence analysis of 16S rRNA, gyrA and rpoB genes. Furthermore, this result indicated that the most effective antagonistic isolates K5‐3 and PPB6 could produce siderophore in iron‐limiting medium, and four kinds of secondary metabolites based on MALDI‐TOF analysis. In addition, the culture filtrates of isolates K5‐3 and PPB6 caused the damage of cell membrane evidenced by the TEM images, and resulted in 73–80% reduction in cell numbers, 55–65% reduction in biofilm formation, and 42–50% reduction in swimming ability of both strains of A. oryzae.
Conclusions
These isolates in particular K5‐3 and PPB6 of halotolerant bacteria markedly inhibited the growth of A. oryzae.
Significance and Impact of the Study
To our knowledge, this is the first report on biological control of halotolerant bacteria against bacterial brown stripe of rice.
A highly pathogenic pig disease emerged in China in 2006, which was characterized by prolonged high fever, red discoloration of the body, and blue ears associated with high mortality. Porcine ...reproductive and respiratory syndrome virus (PRRSV) was isolated as the single most prominent virus in the samples collected from affected pigs. The full-length genomic sequence of the virus revealed two distinct deletions in the non-structural protein 2 (NSP2) in comparison to all previously reported North American genotype PRRSV. Through extensive surveys in 14 different provinces, 56 additional PRRSV isolates were obtained from affected farms. All of the isolates were found to contain identical deletions in NSP2. To confirm the etiology, eight 60-day-old PRRSV-free pigs were divided into two groups and the test group was intranasally infected at a titer of 2 x 10⁵.⁰ tissue culture infectious dose 50 per pig. The inoculated pigs all died at 7, 8, 12, 16, or 21 days post-inoculation with their clinical and pathological findings similar to those in the field. The viruses recovered from dead pigs were identical to the inoculated virus in NSP2 and GP5 genes. Our study shows that the recently emerged PRRSV in China is characterized by two discontiguous deletions in NSP2 and is the cause for the current epizootics in China.
Knowledge of the in-situ stress field in the rock mass at depth is important to provide stress boundary conditions for underground excavation design, stability evaluation, and the optimization of ...ground support systems. In the present study, in-situ stress measurement using hydraulic fracturing method is conducted in the Beishan area in Gansu Province, China, a preferred candidate site for China's high-level radioactive waste repository. Information on the stress magnitudes and orientations in three sub-areas is obtained from 136 measurement points in nine sub-vertical boreholes at depths ranging from 30 to 700m, and the distribution characteristics of the in-situ stress field is analyzed. The pressure–time records obtained from the test intervals with pre-existing fractures are discussed according to the acoustic borehole televiewer (BHTV) images. The measurement results indicate that the regional stress field is dominated by horizontal stress within most of the measurement depth ranges. A piecewise distribution of the principal stresses reveals approximately three stress domains with increasing depth. At shallow and medium depths, the stress fields are characterized by σH>σh>σv and σH>σv>σh, respectively, where σH, σh, and σv are maximum horizontal, minimum horizontal, and vertical stresses, respectively. With further increase of depth, the maximum principal stress changes from horizontal to vertical (i.e. σv>σH>σh). Fracture impression results reveal that the maximum horizontal stress is dominantly oriented in the NNE–NEE direction, which is in agreement with the orientation of regional tectonic stress field generated from movement of the Earth's tectonic plates. In addition, it is found that the orientations of σH are affected by the geological structures significantly.
•Geological features of the Beishan area are described.•The results of the hydro-fracturing in-situ stress measurements are presented.•The distribution characteristics of the in-situ stress filed are analyzed.•The regional stress field associated with the geological evolution is discussed.
Ti6Al4V matrix composites reinforced with needle-like Ti5Si3 particles distributed in the secondary-scale network and TiB whiskers in the first-scale network were in-situ synthesized using reaction ...hot pressing. In order to adjust Ti5Si3 characteristics and improve the mechanical properties of the composites, effects of sintering parameters on microstructure and tensile properties were systematically investigated. The size, distribution and morphology of the Ti5Si3 precipitation can be adjusted by controlling the sintering parameters. The quantity of the Ti5Si3 precipitation in the secondary-scale network (β-Ti phase) increased significantly with increasing temperatures. Moreover, compared with the sintering time, the sintering temperature plays a more dominant role in controlling the microstructure and tensile properties of the composites. The composites fabricated at 1300°C for 1.5h exhibited enhanced tensile properties at both room and elevated temperatures with more and finer Ti5Si3 distributed in the secondary-scale network.
Abstract
Background
This study was the first human validation of the gram-positive bacterial DNA polymerase IIIC target in patients with Clostridioides difficile infection. The primary objectives ...were to assess clinical cure rates and adverse events (AEs). Secondary objectives were to evaluate plasma/fecal pharmacokinetics, microbiologic eradication, microbiome and bile acid effects, and sustained clinical cure (SCC) with ibezapolstat.
Methods
This single-arm, open-label, phase 2a study enrolled adults with C. difficile infection at 4 US centers. Patients received ibezapolstat 450 mg orally every 12 hours for 10 days and followed for an additional 28 days to assess study objectives.
Results
Ten patients with a mean (standard deviation SD) age of 49 15 years were enrolled. Seven AEs were reported classified as mild-moderate. Plasma levels of ibezapolstat ranged from 233 to 578 ng/mL while mean (SD) fecal levels were 416 (494) µg/g stool by treatment day 3 and >1000 µg/g stool by days 8–10. A rapid increase in alpha diversity in the fecal microbiome was noted after starting ibezapolstat therapy, which was maintained after completion of therapy. A proportional decrease in Bacteroidetes phylum was observed (mean change SD, −10.0% 4.8%; P = .04) with a concomitantly increased proportion of Firmicutes phylum (+14.7% 5.4%; P = .009). Compared with baseline, total primary bile acids decreased by a mean (SD) of 40.1 (9.6) ng/mg stool during therapy (P < .001) and 40.5 (14.1) ng/mg stool after completion of therapy (P = .007). Rates of both initial clinical cure and SCC at 28 days were 100% (10 of 10 patients).
Conclusions
In this phase 2a study, 10 of 10 patients achieved SCC, demonstrated favorable pharmacokinetics, minimal AEs, and beneficial microbiome and bile acids results. These results support continued clinical development.
This single-arm, phase 2a study was the first validation of ibezapolstat in adult patients with Clostridioides difficileinfection. Ten of 10 patients achieved sustained clinical cure and demonstrated favorable pharmacokinetics, minimal adverse events, and beneficial microbiome and bile acids results.
This paper investigated the microstructure and mechanical properties of Q235/304 stainless steel clad plate welding seam produced by hybrid welding of tungsten inert gas welding (TIG) and metal ...active gas arc welding (MAG). The results showed that the dual phases containing ferrite and austenite appeared in the stainless steel covering welding (SSCW), while the partial martensite phases appeared in the carbon steel backing welding (CSBW), which is attributed to the dilution behavior of Ni and Cr elements from stainless steel to the Q235 steel results into the movement of the CCT curve to the right side and the decrease of critical martensite formation cooling rate. The CSBW possesses the highest microhardness value in the weld metal due to the existence of the martensite zone. The impact tests were carried out and the results showed that the Charpy absorbed energy of weldments (81 J) is almost equal to that of base clad plate (83 J). The SSCW layer possesses the ductile fracture characteristics accompanying many dimples. However, in the CSBW layer, some cleavage fracture characteristics are presented in the radiation zone while many dimples are located in the fibrous zone, revealing a complex combination of brittle and ductile fracture behavior, which is due to the existence of martensite zone, different stress states and crack propagation velocity.
Highlights
Hybrid (TIG, MAG) welding is suitable for welding stainless steel clad plate;
The martensite formation in CSBW is related to dilution and diffusion of Cr and Ni;
Partial martensite transformation can strengthen and toughen the welding seam.
Carbapenem-resistant Enterobacterales (CRE) pose a significant threat to global public health. The most important mechanism for carbapenem resistance is the production of carbapenemases. Klebsiella ...pneumoniae carbapenemase (KPC) represents one of the main carbapenemases worldwide. Complex mechanisms of blaKPC dissemination have been reported in Colombia, a country with a high endemicity of carbapenem resistance. Here, we characterized the dynamics of dissemination of blaKPC gene among CRE infecting and colonizing patients in three hospitals localized in a highly endemic area of Colombia (2013 and 2015). We identified the genomic characteristics of KPC-producing Enterobacterales recovered from patients infected/colonized and reconstructed the dynamics of dissemination of blaKPC-2 using both short and long read sequencing. We found that spread of blaKPC-2 among Enterobacterales in the participating hospitals was due to intra- and interspecies horizontal gene transfer (HGT) mediated by promiscuous plasmids associated with transposable elements that was originated from a multispecies outbreak of KPC-producing Enterobacterales in a neonatal intensive care unit. The plasmids were detected in isolates recovered in other units within the same hospital and nearby hospitals. The gene “epidemic” was driven by IncN-pST15-type plasmids carrying a novel Tn4401b structure and non-Tn4401 elements (NTEKPC) in Klebsiella spp., Escherichia coli, Enterobacter spp., and Citrobacter spp. Of note, mcr-9 was found to coexist with blaKPC-2 in species of the Enterobacter cloacae complex. Our findings suggest that the main mechanism for dissemination of blaKPC-2 is HGT mediated by highly transferable plasmids among species of Enterobacterales in infected/colonized patients, presenting a major challenge for public health interventions in developing countries such as Colombia.
We investigate forward‐looking commodity price volatility expectations (proxied by option‐implied volatilities or IVols) around scheduled US Department of Agriculture (USDA) reports. We show that ...corn and soybean IVols are significantly lower for several trading days after a report. The IVol response to a release depends on agricultural market experts' disagreement and sentiment before the USDA report, and on the extent to which the USDA information surprises the market. Whereas commodity IVols are generally positively related to financial‐market sentiment and macroeconomic uncertainty (jointly captured by the volatility index VIX), this comovement breaks down on report days—with the VIX and commodity IVols moving in opposite directions.
The back-streaming neutrons (back-n) is a white neutron experimental facility at the China spallation neutron source (CSNS). The time structure of the primary proton beam makes it fully applicable to ...use the time-of-flight (TOF) method for neutron energy measuring. We implemented the electronics of TOF measurement on the general-purpose readout electronics designed for all the seven detectors in back-n. The electronics are based on the peripheral component interconnect express eXtensions for instrumentation (PXIe) platform, which is composed of field digitizer modules (FDM), trigger and clock modules (TCM), and signal conditioning modules. The T0 signal synchronous to the CSNS accelerator represents the neutron emission from the target. It is the start of the time stamp. The TCM receives, synchronizes, and distributes the T0 signal to each FDM based on the PXIe backplane bus. Meanwhile, the detector signals, after being conditioned, are fed into FDMs for waveform digitizing. The first sample point of the signal waveform is the stop of the time stamp. According to the time stamp and the time of the signal over the threshold, the total TOF can be obtained. The time-to-digital converter (TDC) based on field-programmable gate array (FPGA) is implemented on the TCM to accurately acquire the time interval between the asynchronous T0 signal and the global synchronous clock phase. There is also an FPGA-based TDC on the FDM to accurately acquire the time interval between the T0 signal arriving at the FDM and the first sample point of the signal waveform. The over-threshold time of signal is obtained offline. This method for TOF measurement is efficient and not needed for additional modules. Test results showed that the accuracy of TOF is subnanosecond and can meet the requirement for back-n at the CSNS.
We report our clinical experience treating a critically ill patient with polymicrobial infections due to multidrug-resistant
,
, and
in a 56-year-old woman who received health care in India and was ...also colonized by
A precision medicine approach using whole-genome sequencing revealed a multiplicity of mobile elements associated with NDM-1, NDM-5, and OXA-181 and, supplemented with susceptibility testing, guided the selection of rational antimicrobial therapy.
PDF
