Cross-phase modulation in two-dimensional spectroscopy.

Developing from transient absorption (TA) spectroscopy, two-dimensional (2D) spectroscopy with pump-probe geometry has emerged as a versatile approach for alleviating the difficulty in implementing 2D spectroscopy with other geometries. However, the presence of cross-phase modulation (XPM) in TA spectroscopy introduces significant spectral distortions, particularly when the pump and probe pulses overlap. We demonstrate that this phenomenon is extended to the 2D spectroscopy with pump-probe geometry and the XPM is induced by the interference of the two pump pulses. We present the oscillatory behavior of XPM in the 2D spectrum and its displacement with respect to the waiting time delay through both experimental measurements and numerical simulations. Additionally, we explore the influence of probe pulse chirp on XPM and discover that by compressing the chirp, the impact of XPM on the desired signal can be reduced.

Development of a reverse transcription recombinase-aided amplification assay for the detection of coxsackievirus A10 and coxsackievirus A6 RNA.

Hand, foot and mouth disease (HFMD) is a serious public health problem, and coxsackievirus A6 (CVA6) and coxsackievirus A10 (CVA10) are two of the major causative pathogens, in addition to enterovirus 71 (EV71) and coxsackievirus A16 (CVA16). A simple and rapid reverse transcription recombinase-aided amplification assay (RT-RAA) was developed for the detection of CVA10 and CVA6 in this study. The analytical sensitivity for detection of CVA10 and CVA6 at 95% probability by probit regression analysis was 35 copies per reaction and 38 copies per reaction, respectively, with 100% specificity. Compared with commercial RT-qPCR assays, when testing 455 fecal specimens, the kappa value of the RT-RAA assay for CVA10 and CVA6 was 0.920 (p < 0.001) and 0.952 (p < 0.001), respectively. Moreover, four samples that were positive for CVA10 and five that were positive for CVA6 by RT-RAA but negative by RT-qPCR were further determined to be true positives. These results demonstrate that the proposed RT-RAA assays are very valuable tools for the detection of CVA10 and CVA6 and have potential for use in resource-limited settings.

Adenovirus associated with acute diarrhea: a case-control study.

BACKGROUND: Diarrhea is a major source of morbidity and mortality among young children in low-income and middle-income countries. Human adenoviruses (HAdV), particular HAdV species F (40, 41) has been recognized as important causal pathogens, however limited data exist on molecular epidemiology of other HAdV associated with acute gastroenteritis. METHODS: In the present preliminary study, we performed a case-control study involving 273 children who presented diarrheal disease and 361 healthy children matched control in Children's hospital of Hebei Province (China) to investigate the relationship between non-enteric HAdV and diarrhea. HAdV were detected and quantified using quantitative real-time PCR (qPCR) and serotyped by sequencing and phylogenetic analysis. Odds ratio (OR) was used to assess the risk factor of HAdV. RESULTS: HAdV were detected in 79 (28.94%) of 273 children with diarrhea including 7 different serotypes (HAdV 40, 41, 3, 2,1,5 and 57) with serotypes 40, 41 and 3 being the most dominant and in 26 (7.20%) of 361 healthy children containing 9 serotypes (HAdV 40, 41, 3, 2,1,5,57,6 and 31). A majority (91.14%) of HAdV positives occurred in diarrhea children and 65.38% in controls< 3 years of age. No significant difference in the viral load was found between case and control groups or between Ad41-positive patients and healthy controls. In addition to HAdV 40 and 41, HAdV 3 was also associated with diarrhea (OR = 17.301, adjusted OR = 9.205, p < 0.001). CONCLUSIONS: Our results demonstrate a high diversity of HAdV present among diarrhea and healthy children and implicate that non-enteric HAdV3 may lead to diarrhea.

Impact of insulin resistance on IVF/ICSI outcomes in women with polycystic ovary syndrome: A systematic review and meta-analysis.

OBJECTIVE: To evaluate the effect of insulin resistance (IR) on in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) outcomes in patients with polycystic ovary syndrome (PCOS). STUDY DESIGN: PubMed, Google Scholar,Web of Science, Embase, Scopus and the Cochrane Library were searched to identify relevant studies. A total of 6,137 PCOS women undergoing IVF/ICSI with or without IR were included in the systematic review and meta-analysis. RESULTS: The systematic review and meta-analysis included twelve observational studies that were free from inherent bias. When comparing PCOS women undergoing IVF/ICSI, the IR and non-IR groups did not show significant differences in oocytes retrieved (WMD = -0.63, 95 % CI: -2.37 to 1.12, P = 0. 483), fertilization rate (WMD = 1.01, 95 % CI: -0.66 to 2.67, P = 0.236; OR = 0.97, 95 % CI: 0.79 to 1.19, P = 0.783), and live birth rate (OR = 1.02, 95 % CI: 0.78 to 1.33, P = 0.892). However, the group with IR had a lower number of MII oocytes (WMD = -1.07, 95 % CI: -1.54 to -0.59, P < 0.001), total embryos (WMD = -1.37, 95 % CI: -1. 78 to -0.95, P < 0.001), and clinical pregnancy rate (OR = 0.77, 95 % CI: 0.59 to 0.99, P = 0.042), as well as a higher miscarriage rate (OR = 1.11, 95 % CI: 1.02 to 1.22, P = 0.017) compared to the non-IR group. CONCLUSION: In women with PCOS, IR had a negative impact on IVF/ICSI outcomes. To obtain more favourable empirical support, larger studies are necessary.

Extracting double-quantum coherence in two-dimensional electronic spectroscopy under pump-probe geometry.

Two-dimensional electronic spectroscopy (2DES) can be implemented with different geometries, e.g., BOXCARS, collinear, and pump-probe geometries. The pump-probe geometry has the advantage of overlapping only two beams and reducing phase cycling steps. However, its applications are typically limited to observing the dynamics with single-quantum coherence and population, leaving the challenge to measure the dynamics of the double-quantum (2Q) coherence, which reflects the many-body interactions. We demonstrate an experimental technique in 2DES under pump-probe geometry with a designed pulse sequence and the signal processing method to extract 2Q coherence. In the designed pulse sequence, with the probe pulse arriving earlier than the pump pulses, our measured signal includes the 2Q signal as well as the zero-quantum signal. With phase cycling and data processing using causality enforcement, we extract the 2Q signal. The proposal is demonstrated with rubidium atoms. We observe the collective resonances of two-body dipole-dipole interactions in both the D1 and D2 lines.

Use of a rapid reverse-transcription recombinase aided amplification assay for respiratory syncytial virus detection.

In this study, a rapid reverse-transcription recombinase aided amplification (RT-RAA) assay was developed to detect respiratory syncytial virus (RSV) subgroups A and B, respectively. The reaction was performed at 39°C in less than 30min. The analytical sensitivities of RSVA and RSVB at 95% probability by probit regression analysis were 38copies per reaction and 35 copies per reaction, respectively, and no cross reactions with other related respiratory viruses were observed. The RT-RAA assay was further utilized to detect and subgroup 306 clinical specimens and the results showed that 79(25.82%, 79/306) samples were positive for RSV, of those 16(20.25%, 16/79) were identified as RSVA and 63(79.75%, 63/79) were RSVB, which is completely consistent with the results obtained by RSV RT-qPCR assay. In conclusion, the developed RAA assay will be of benefit as a faster, sensitive and specific alternative tool for detection of RSV.