To detect
Salmonella
more efficiently and isolate strains more easily, a novel and simple detection method that uses an enrichment assay and two chromogenic reactions on a chromatography membrane was ...developed. Grade 3 chromatography paper is used as functionalized solid phase support (SPS), which contains specially optimized medium. One reaction for screening is based on the sulfate-reducing capacity of
Salmonella
. Hydrogen sulfide (H
2
S) generated by
Salmonella
reacts with ammonium ferric citrate to produce black colored ferrous sulfide. Another reaction is based on
Salmonella
C8 esterase that is unique for
Enterobacteriaceae
except
Serratia
and interacts with 4-methylumbelliferyl caprylate (MUCAP) to produce fluorescent umbelliferone, which is visible under ultraviolet light. A very low detection limit (10
1
CFU ml
−1
) for
Salmonella
was achieved on the background of 10
5
CFU ml
−1
Escherichia coli
. More importantly, testing with more than 1,000 anal samples indicated that our method has a high positive detection rate and is relatively low cost, compared with the traditional culture-based method. It took only 1 day for the preliminary screening and 2 days to efficiently isolate the
Salmonella
cells, indicating that the new assay is specific, rapid, and simple for
Salmonella
detection. In contrast to the traditional culture-based method, this method can be easily used to screen and isolate targeted strains with the naked eye. The results of quantitative and comparative experiments showed that the visual detection technique is an efficient alternative method for the screening of
Salmonella spp.
in many applications of large-sized samples related to public health surveillance.
The focal plane camera is the core component of the Wide Field-of-view Cherenkov/fluorescence Telescope Array (WFCTA) of the Large High-Altitude Air Shower Observatory (LHAASO). Because of the ...capability of working under moonlight without aging, silicon photomultipliers (SiPM) have been proven to be not only an alternative but also an improvement to conventional photomultiplier tubes (PMT) in this application. Eighteen SiPM-based cameras with square light funnels have been built for WFCTA. The telescopes have collected more than 100 million cosmic ray events and preliminary results indicate that these cameras are capable of working under moonlight. The characteristics of the light funnels and SiPMs pose challenges (e.g. dynamic range, dark count rate, assembly techniques). In this paper, we present the design features, manufacturing techniques and performances of these cameras. Finally, the test facilities, the test methods and results of SiPMs in the cameras are reported here.
Previous studies have emphasized that the decrease in
photolysis rate at the surface induced by the light extinction of aerosols
could weaken ozone photochemistry and then reduce surface ozone. ...However,
quantitative studies have shown that weakened photochemistry leads to a much
greater reduction in the net chemical production of ozone, which does not
match the reduction in surface ozone. This suggests that in addition to
photochemistry, some other physical processes related to the variation of
ozone should also be considered. In this study, the Weather Research and
Forecasting with Chemistry (WRF-Chem) model coupled with the ozone source
apportionment method was applied to determine the mechanism of ozone
reduction induced by aerosols over central East China (CEC). Our results
showed that weakened ozone photochemistry led to a significant reduction in
ozone net chemical production, which occurred not only at the surface but
also within the lowest several hundred meters in the planetary boundary
layer (PBL). Meanwhile, a larger ozone gradient was formed in the vertical
direction, which led to the high concentrations of ozone aloft being
entrained by turbulence from the top of the PBL to the surface and partly
counteracting the reduction in surface ozone. In addition, contribution from
dry deposition was weakened due to the decrease in surface ozone
concentration. The reduction in the ozone's sink also slowed down the
rate of the decrease in surface ozone. Ozone in the upper layer of the
PBL was also reduced, which was induced by much ozone aloft being entrained
downward. Therefore, by affecting the photolysis rate, the impact of
aerosols was a reduction in ozone not only at the surface but also
throughout the entire PBL during the daytime over CEC in this study. The
ozone source apportionment results showed that 41.4 %–66.3 % of the
reduction in surface ozone came from local and adjacent source regions,
which suggested that the impact of aerosols on ozone from local and adjacent
regions was more significant than that from long-distance regions. The
results also suggested that while controlling the concentration of aerosols,
simultaneously controlling ozone precursors from local and adjacent source
regions is an effective way to suppress the increase in surface ozone over
CEC at present.
•A speeding prediction model is established based on quantifying the visual road environment to improve pre-waring systems.•A visual road environment model consists of two parts, including the visual ...road geometry and visual roadside environment.•Random Forests were then applied to build the speeding prediction model and variable importance was calculated.•Under both levels of the speeding criterion, the speeding prediction model performed well with high out-of-bag accuracy.•This model could predict drivers’ speeding behavior at the future position located a sighting distance away.
Speeding is one of the major contributors to traffic crashes. To solve this problem, speeding prediction is recognized as a critical step in a pre-warning system. While previous studies have shown that speeding is affected by road environmental design, research in predicting speeding behavior through road environment features has not yet been conducted. Furthermore, there is a large discrepancy between actual and perceived road environmental information given that a driver’s visual perception plays a crucial role as the dominant source of information in determining driver’s behavior. Thus, this paper aims to establish a speeding prediction model based on quantifying the visual road environment to improve the design of pre-waring systems, which can predict whether drivers are going to speed and provide them with visual or/and audio warnings about their current driving speed and the speed limit prior to the occurrence of speeding behavior. Twenty input variables derived from three categories including visual road environment parameters, vehicle kinematic features, and driver characteristics were considered in the proposed speeding prediction model. Especially, the road environmental design factors consisting of the visual road geometry and visual roadside environment as perceived by the driver’s eyes were quantified using a visual road environment model. Field experiments were conducted to collect naturalistic driving data concerning speeding behavior on the typical two-lane mountainous rural highways in five provinces of China. Random Forests, an ensemble learning method for regression and classification, were applied to build the speeding prediction model and variable importance was calculated. Additionally, logistic regression was used as a supplement to further investigate factors impacting on speeding behavior. A speeding criterion was defined with two levels in this study: a lower level (exceeding the posted speed limit) and a higher level (10% above the posted speed limit). Under both levels of the speeding criterion, the speeding prediction model performed well with high accuracy (over 85%). This model could use the value of the variables obtained from the current position to predict drivers’ speeding behavior at the future position located a sighting distance away. This interval was sufficient for a pre-warning system to give a speeding warning that a driver with normal perception-reaction time (around 2.5 s) could respond to. Findings in this study can be used to effectively predict speeding in advance and help to reduce speeding-related traffic accidents.
Tumor recurrence remains the main reason for breast cancer-associated mortality, and there are unmet clinical demands for the discovery of new biomarkers and development of treatment solutions to ...benefit patients with breast cancer at high risk of recurrence. Here we report the identification of chromosomal copy-number amplification at 1q21.3 that is enriched in subpopulations of breast cancer cells bearing characteristics of tumor-initiating cells (TICs) and that strongly associates with breast cancer recurrence. Amplification is present in ∼10-30% of primary tumors but in more than 70% of recurrent tumors, regardless of breast cancer subtype. Detection of amplification in cell-free DNA (cfDNA) from blood is strongly associated with early relapse in patients with breast cancer and could also be used to track the emergence of tumor resistance to chemotherapy. We further show that 1q21.3-encoded S100 calcium-binding protein (S100A) family members, mainly S100A7, S100A8, and S100A9 (S100A7/8/9), and IL-1 receptor-associated kinase 1 (IRAK1) establish a reciprocal feedback loop driving tumorsphere growth. Notably, this functional circuitry can be disrupted by the small-molecule kinase inhibitor pacritinib, leading to preferential impairment of the growth of 1q21.3-amplified breast tumors. Our study uncovers the 1q21.3-directed S100A7/8/9-IRAK1 feedback loop as a crucial component of breast cancer recurrence, serving as both a trackable biomarker and an actionable therapeutic target for breast cancer.
The structure genes spike (S), nucleocapsid (N), membrane (M), small membrane (sM) of a porcine epidemic diarrhea virus (PEDV) strain DX isolated in Gansu province, North-west of China, were cloned, ...sequenced and compared with published sequences of PEDV strains. The nucleotide sequences encoding the entire S, sM, M and N genes open reading frame (ORF) of DX were 4 152, 231, 681 and 1 326 bases long respectively. There were transcription regulatory sequences (TRSs) upstream of the initiator ATG of the S, N and M genes. The amino acids sequences of S, M and N contained 30, 3 and 7 potential asparagine (N)-linked glycosylation sites. Homologous analysis and phylogenetic trees showed that DX had the closest relationship with strains LJB/06, JS-2004-2Z and CH/HLJH/06 that were also isolated from China and indicated the prevalence of some PEDV isolates in China were widespread since the JS-2004-2Z strain originated from the south of the China, and LJB/06 and CH/HLJH/06 were isolated from northeast China. The N gene was cloned using two primers which contained
Nco
I and
Bam
H I restriction enzyme sites and subcloned into expression vector pET30a. The recombinant plasmid was then transformed into
E.coli
Rossta. SDS-PAGE showed there was a protein of about 55kDa as expected and Western blot indicated the N protein had biological activity.
Activated androgen receptor binds to androgen-responsive elements (AREs) in genome to regulate target gene transcription and, consequently, mediates physiological or tumorigenic processes of the ...prostate. Our aim was to determine whether genetic variants in AREs are associated with clinical outcomes after androgen-deprivation therapy (ADT) in prostate cancer patients.
We systematically investigated 55 common single-nucleotide polymorphisms (SNPs) in the genome-wide insilico-predicted AREs in a cohort of 601 men with advanced prostate cancer treated with ADT. The prognostic significance of these SNPs on disease progression, prostate cancer-specific mortality (PCSM) and all-cause mortality (ACM) after ADT was assessed by Kaplan-Meier analysis and Cox regression model.
In univariate analysis, two, five, and four SNPs were associated with disease progression, PCSM, and ACM, respectively. After adjusting for known prognostic factors, ARRDC3 rs2939244, FLT1 rs9508016, and SKAP1 rs6504145 remained as significant predictors for PCSM and FBXO32 rs7830622 and FLT1 rs9508016 remained as significant predictors for ACM in multivariate analysis. Moreover, strong combined genotype effects on PCSM and ACM were also observed (P
< 0.001).
Our results suggest that SNPs in AREs influence prostate cancer survival and may further advance our understanding of the disease progression.
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