No abstract

No abstract

No abstract

Detection resolution is crucial for improvement of the measurement precision in the device and instrument. Because of the limited resolution, a fuzzy area with the truth-value as its center is found during the detection. The finding for improving the measurement precision by the border of fuzzy area is first introduced. The higher resolution can be captured by the higher resolution stability which makes the different detection results of the inner and outer fuzzy area on the border reflected more sensitively between the measure and the reference quantity. The system resolution obtained only depends on the stability of measurement resolution, which is much better than the measurement resolution itself. Based on the finding, the measurement precision can be improved two or three orders of magnitude. The finding can be used in various kinds of high precision measurement.

The etiology of hypertriglyceridemia (HTG) and acute pancreatitis (AP) is complex. Herein, we dissected the underlying etiology in a patient with HTG and AP. The patient had a 20-year history of heavy alcohol consumption and an 8-year history of mild HTG. He was hospitalized for alcohol-triggered AP, with a plasma triglyceride (TG) level up to 21.4 mmol/L. A temporary rise in post-heparin LPL concentration (1.5–2.5 times of controls) was noted during the early days of AP whilst LPL activity was consistently low (50∼70% of controls). His TG level rapidly decreased to normal in response to treatment, and remained normal to borderline high during a ∼3-year follow-up period during which he had abstained completely from alcohol. Sequencing of the five primary HTG genes (i.e., LPL, APOC2, APOA5, GPIHBP1 and LMF1) identified two heterozygous variants. One was the common APOA5 c.553G > T (p.Gly185Cys) variant, which has been previously associated with altered TG levels as well as HTG-induced acute pancreatitis (HTG-AP). The other was a rare variant in the LPL gene, c.756T > G (p.Ile252Met), which was predicted to be likely pathogenic and found experimentally to cause a 40% loss of LPL activity without affecting either protein synthesis or secretion. We provide evidence that both a gene-gene interaction (between the common APOA5 variant and the rare LPL variant) and a gene-environment interaction (between alcohol and digenic inheritance) might have contributed to the development of mild HTG and alcohol-triggered AP in the patient, thereby improving our understanding of the complex etiology of HTG and HTG-AP.

Background: Recent studies have shown that bile acids (BAs) are closely related to metabolic and inflammatory diseases. Our study aimed to investigate whether circulating total bile acid (TBA) levels were associated with the severity of acute pancreatitis (AP). Methods: We retrospectively collected data on patients diagnosed with AP in a tertiary center from 01 January 2014 to 31 December 2016. The highest TBA value during the first 1,2,3,5,7 days after admission was determined as D1, D2, D3, D5, D7 TBA max. Patients were divided into the high TBA (HTBA) group and the normal TBA (NTBA) group according to whether the TBA max was ≥10 μmol/L. The prognosis and complications, including death, organ failure (OF) and pancreatic necrosis, were compared between the two groups. Logistic regression analysis and receiving operating characteristic (ROC) curve were used to evaluate the relationship between circulating TBA and organ failure in AP patients. Results: Through stratified analysis of each time period, we found that the incidence of OF in the HTBA group was significantly higher than that in the NTBA group, and the AP severity classification in the HTBA group was more serious than that in the NTBA group. In addition, according to the D7 TBA max values, the pancreatic necrosis rate, percutaneous catheter drainage (PCD) rate and mortality in the HTBA group were higher than those in the NTBA group. Multivariate regression analysis showed that HTBA (odds ratio (OR), 4.894; P = 0.002) was an independent risk factor for AP complicated with OF, which was verified in the grouping based on D7 TBA max. ROC analysis revealed that a circulating D7 TBA max cutoff point of 6.450 umol/L had optimal predictive value for the development of OF in AP patients with an area under the curve of the ROC curve (AUCROC) of 0.777. Conclusions: The increase of circulating TBA in early stage of AP is independently related to organ failure, which indicates the adverse prognosis of AP patients.

To achieve high-precision fiber-optic time transfer, the method of two-way transmission is usually used. Therefore in this paper we propose to develop a high-precision long-haul fiber-optic time transfer between multi stations by simultaneously transferring the 1 pluse per second signal, time code signal and 10 MHz frequency signal over single fiber with the same wavelength, and adopting the time division multi address (TDMA) as well as the purification and regeneration method at individual station. In this proposal, the equipment at each remote station has its own address, and the equipment at the local station can establish the periodic two-way time transfer with any remote station by using the TDMA method, therefore each remote station is synchronized with the local station. To avoid the superimposed effect of optical noises during propagation in fiber, the optical-electro-optical relay amplifiers are utilized. In the meantime the propagation delay of the fiber link is compensated for at each remote station. With the self-developed engineering prototypes, the experimental verifications are subsequently conducted both in laboratory and real field. In the laboratory, the experimental setup is built by cascading 11 rolls of 50 km-long fiber coils, and locating three monitoring devices at different fiber distances of 50, 300, and 550 km from the local station. The stabilities of the time transfer at these three points are achieved to be 16.7, 16.8, and 18.4 ps in standard deviation, and the time deviations are 1.78, 2.09, and 2.92 ps at an averaging time of 1000 s respectively. In the real field test, a field fiber link of 871.6 km in length is utilized, along which 11 self-developed time-frequency transceivers are set at the cascaded fiber-optic stations. Since only the 11th remote station is co-located at the local station, the performance and the time transfer between the 11th remote station and the local station are measured accurately. The time transfer is experimentally demonstrated with the time standard deviation of 29.8 ps and the time deviations of 3.85 ps/1000 s. The timing uncertainty on the field fiber link is also checked and gives a value of 25.4 ps. To further improve the long-term stability of time transfer, the more accurate thermal control of the lasers used in the system should be adopted to reduce the optical wavelength drift. By compressing the bandwidth of the phase locked loop module in each remote device, the short-term stability of time synchronization can also be better. This proposal can also be extended to the fiber networks with star-shaped and chain-shaped connections. Therefore time synchronization in even larger areas and more stations can be realized.

In this research, we demonstrate an optical frequency comb (OFC) based on a turnkey mode-locked laser with a figure-9 structure and polarization-maintaining fibers for frequency comparison between optical clocks with wavelengths of 698 nm, 729 nm, 1068 nm and 1156 nm. We adopt a multi-branch approach in order to produce high power OFC signals at these specific wavelengths, enabling the signal-to-noise ratio of the beatnotes between the OFC and the clock lasers beyond 30 dB at a resolution bandwidth of 300 kHz. This approach makes the supercontinuum spectra generating process much easier in comparison to a single branch OFC; however, more out-of-loop fibers degrade the long term frequency instability due to thermal drift. To minimize the thermal drift effect, we set the fiber lengths of different branches to be similar, and we stabilize the temperature as well. The out-of-loop frequency instability of the OFC due to the incoherence of the multi-branch is about 5.5×10-19 @ 4000 s, while the in-loop frequency instability of f ceo and that of f beat are 7.5×10-18 @1 s and 8.5×10-18 @1 s, respectively. The turnkey OFC meets the requirement of frequency comparison between the best optical clocks.