In this article, the analyticity of triangle loop integral with complex masses of internal particles is discussed in a new perspective, based on which we obtain the explicit width dependence of the ...absorptive part of the triangle amplitude. We reanalyze the decay pattern of η(1405/1475) with the width effects included in the triangle singularity (TS) mechanism. Based on the present experimental information, we provide a self-consistent description of the KK¯π, ηππ, and 3π decay channels for η(1405/1475). Our results confirm the claim that the TS mechanism plays a decisive role in the understanding of the η(1405) and η(1475) puzzle. Namely, the observed differences of η resonances within the mass region of 1.40–1.48 GeV are originated from the same state. For the isospin violated process J/ψ→γη(1405/1475)→f0(980)π→3π, we identify an additional contribution to the a0(980)−f0(980) mixing via the TS mechanism.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
We show that the Pomeron exchanges play a unique role in vector charmonium scatterings. Such a mechanism can provide a natural explanation for the nontrivial structures in the di-J/ψ spectrum ...observed by the LHCb Collaboration. The narrow structure X(6900), as a dynamically generated resonance pole, can arise from the Pomeron exchanges and coupled-channel effects between the J/ψ-J/ψ, J/ψ-ψ(2S) scatterings. A pole structure near the di-J/ψ threshold is also found. Meanwhile, we predict that X(6900) can produce significant threshold enhancement in the J/ψ-ψ(2S) energy spectrum which can be searched for at LHCb.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We present a systematic study of the productions and decays of light axial vector mesons with JPC = 1+± in charmonium decays. In the quark-model scenario, the two axial vector nonets are connected to ...each other by the Gell-Mann–Okubo mass relation through the mixing between two K1 states i.e., K1(1270) and K1 (1400) with configurations of 3P1 and 1P1. The mixing angles between f1 and f′1 i.e., f1 (1285) and f1 (1420) and between h1 and h′1 i.e., h1 (1170) and h1 (1415) can be reliably constrained. We then introduce the intermediate K∗K+ c . c . meson loop transitions in the description of the productions and decays of these axial vector mesons. The presence of the nearby S -wave K∗K+ c.c., to which these axial vector mesons have strong coupling strengths, turns out to be crucial for understanding many puzzling questions related to their production and decay. This is because the S-wave K∗K+ c. c. rescatterings by the kaon exchange satisfy the triangle singularity (TS) condition in some of these cases and the TS mechanism can introduce special interference effects into the exclusive decays of these light axial vector mesons.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
Hepatitis B virus (HBV) infection is the major public health problem worldwide. In clinical practice, serological and molecular assays are the most commonly used diagnostic methods to detect HBV ...infection in clinical practices.
Here we present a rapid and sensitive recombinase aided amplification assay (RAA) to detect HBV at 39.0 °C for 30 min without DNA extraction from serum samples. The analytical sensitivity of RAA assay was 100 copies per reaction and showed no cross reaction with human immunodeficiency virus (HIV) and hepatitis C virus (HCV). The universality of RAA assay was validated by testing of 41 archived serum samples with predefined HBV genotypes (B, C and D).
A total of 130 archived suspected HBV infected serum samples were detected by commercial qPCR with DNA extraction and RAA assay without DNA extraction (heat-treatment). Compared with qPCR assay as a reference, the RAA assay obtained 95.7% sensitivity and 100% specificity and a kappa value of 0.818.
We developed a rapid, convenient, highly sensitive and specific method to detect HBV without DNA extraction in clinical samples. This RAA method of HBV detection is very suitable for clinical testing.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Multiplex real‐time quantitative polymerase chain reaction (mRT‐qPCR) assay is commonly used to detect respiratory viruses, however, the sensitivity is limited for most reports. A panel of locked ...nucleic acid based multiplex closed one‐tube nested real‐time PCR (mOTNRT‐PCR) assay consisting of five separate internally controlled RT‐qPCR assays was developed for detection of 14 respiratory viruses. The sensitivity and reproducibility of mOTNRT‐PCR panel were evaluated using plasmid standards and the specificity was evaluated using clinical samples. The clinical performance of mOTNRT‐PCR panel was further evaluated with 468 samples collected from patients with an acute respiratory infection and compared with individual real‐time PCR (RT‐qPCR) assay. The analytical sensitivities of mOTNRT‐PCR panel ranged from 2 to 20 copies/reaction, and no cross‐reaction with common respiratory viruses was observed. The coefficients of variation of intra‐assay and inter‐assay were between 0.35% and 8.29%. Totally 35 clinical samples detected by mOTNRT‐PCR assay panel were missed by RT‐qPCR and confirmed true positive by sequencing of nested PCR products. The mOTNRT‐PCR assay panel provides a more sensitive and high‐throughput method for the detection of 14 respiratory viruses.
Research Highlights
A panel of mOTNRT‐PCR consisted of five separate internally controlled RT‐qPCR assay.
Locked nucleic acid was used to develop the mOTNRT‐PCR assay panel.
The sensitivity of mOTNRT‐PCR panel ranged from 2‐20copies/reaction using plasmid.
mOTNRT‐PCR was more sensitive than reported individual RT‐qPCR assay.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The most prevalent viruses currently causing diarrhea are norovirus and rotavirus, and rapid and sensitive detection methods are essential for the early diagnosis of disease. The purpose of this ...study was to establish a sensitive single‐tube two‐stage nucleic acid amplification method—reverse transcription recombinase‐assisted PCR (RT‐RAP)—for simultaneous detection of norovirus GII and group A Rotavirus, with the first stage consisting of isothermal reverse transcription recombinase‐aided amplification (RT‐RAA) and the second stage consisting of qPCR (quantitative PCR). RT‐RAP is more sensitive than either RT‐RAA or qRT‐PCR (quantitative RT‐PCR) alone. And the addition of a barrier that can be disassembled after heating enabled the detection of samples within 1 h in a single closed tube. Sensitivity was 10 copies/reaction of norovirus (Novs) GII and group A rotavirus (RVA). In parallel, two hundred fecal specimens were used to evaluate the method and compare it with a commercial fluorescent quantitative RT‐PCR. The data showed kappa values of 0.957 and 0.98 (p < 0.05) for detecting Novs GII and RVA by the two methods, indicating the potential of the newly established assay to be applied to clinical and laboratory testing.
A sensitive single‐tube two‐stage nucleic acid amplification method—reverse transcription recombinase‐assisted PCR (RT‐RAP)—for simultaneous detection of norovirus GII and group A Rotavirus with the first stage consisting of isothermal reverse transcription recombinase‐aided amplification (RT‐RAA) and the second stage consisting of qPCR (quantitative PCR).
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Increasing number of hospitalized children with community acquired pneumonia (CAP) is co-detected with Mycoplasma pneumoniae (Mp). The clinical characteristics and impact of Mp co-detected with other ...bacterial and/or viral pathogens remain poorly understood. The purpose of this study was to evaluate the demographic and clinical features of CAP children with Mp mono-detection and Mp co-detection. A total of 4148 hospitalized children with CAP were recruited from January to December 2017 at the Children's Hospital of Hebei Province, affiliated to Hebei Medical University. A variety of respiratory viruses, bacteria and Mp were detected using multiple modalities. The demographic and clinical features of CAP children with Mp mono-detection and Mp co-detection were recorded and analyzed. Among the 110 CAP children with Mp positive, 42 (38.18%) of them were co-detected with at least one other pathogen. Co-detection was more common among children aged less than or equai to3 years. No significant differences were found in most clinical symptoms, complications, underlying conditions and disease severity parameters among various etiological groups, with the following exceptions. First, prolonged duration of fever, lack of appetite and runny nose were more prevalent among CAP children with Mp-virus co-detection. Second, Mp-virus (excluding HRV) co-detected patients were more likely to present with prolonged duration of fever. Third, patients co-detected with Mp-bacteria were more likely to have abnormal blood gases. Additionally, CAP children with Mp-HRV co-detection were significantly more likely to report severe runny nose compared to those with Mp mono-detection. Mp co-detection with viral and/or bacterial pathogens is common in clinical practice. However, there are no apparent differences between Mp mono-detection and Mp co-detections in terms of clinical features and disease severity.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
PDF
