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We developed a multiplex ligation-dependent probe amplification (MLPA) assay for the simultaneous detection of 6 clinically relevant viral pathogens causing porcine reproductive failure, that is porcine reproductive and respiratory syndrome virus (PRRSV), Japanese encephalitis virus (JEV), classical swine fever virus (CSFV), porcine circovirus type 2 (PCV2), pseudorabies virus (PRV) and porcine parvovirus (PPV). The limits of detection for the assay varied among the 6 target organisms from 1 to 8 copies per MLPA assay. The MLPA assay was evaluated with 346 heparinized porcine umbilical cord blood specimens, and the results of the assay were compared to those of real-time PCR. The MLPA assay showed specificities and sensitivities of 99.2% and 100%, respectively, for PRRSV; 100% and 100%, respectively, for CSFV, PCV2, PRV and PPV. No sample was found to be positive for JEV by either the MLPA assay or the real-time PCR. In conclusion, the MLPA assay has comparable clinical sensitivity to that of real-time PCR assay and provides a useful tool for fast screening porcine reproductive failure-associated viruses.

On-line measurement of oil well multi-phase flow split-phase content is of great significance to the analysis of oil well production dynamics. This paper proposes an online measurement model of oil-well multi-phase flow split-phase measurement based on multi-sensors of differential pressure device and radio frequency device, and conducts experiments. This paper explores the close relationship between the pressure fluctuation signal of the gas-liquid two-phase flow and the parameters of the two-phase flow, such as the flow pattern, gas phase content and other parameters, analyzes the characteristic values of the differential pressure fluctuation signal, and establishes a number of dimensionless parameters and gas phase The relationship model of the content rate; considering the influence of temperature, fluid state, salinity and other factors on the radio frequency moisture content measurement, an optimized support vector machine moisture content data fusion measurement model is established. A gas-liquid measurement sample is obtained through a laboratory multi-phase flow verification and calibration device, and multiple linear regression correction is performed on the differential pressure method flow test data to obtain a correlation with better measurement accuracy. Experimental research shows that the oil volume multi-phase flow split-phase metering model established in this paper has a liquid volume error of less than 5%, a water cut error of less than 2%, and a gas volume error of less than 10%, which improves the application range and measurement accuracy of oil well multi-phase flow measurement.

A novel microporous metal–organic framework (FJU-44), with abundant accessible nitrogen sites on its internal surface, was constructed from the tetrapodal tetrazole ligand tetrakis(4-tetrazolylphen...

A hollow core-shell nanosphere with sandwiched Pd nanoparticles between two-layered mesoporous silica was designed through layer-by-layer assembly. The nanocomposite exhibited outstanding catalytic activity and thermal stability in Suzuki coupling reactions of aryl bromides and arylboronic acids. The conversion of bromobenzene was up to 82.8% in 1 h and 68.2% in 5 min, and the sandwich structure was well-kept after running five cycles, with few Pd NPs mass loss.

To reduce the warping stress of the thin-walled steel box beam subjected to restrained torsion, transverse stiffening ribs are set. The warping stress is calculated by the finite element software ANSYS considering the influence of the stiffening ribs of the thin-walled box beam with different forms and different spacing intervals. There are four different stiffening rib's forms to be analyzed and compared. It can be concluded that the stiffening ribs with hollow rectangle section can significantly reduce warping stress in the thin-walled box beam and save the materials at the same time. The other conclusion is the warping stress in the thin-walled box beam will decrease remarkably only when the spacing interval of the stiffening ribs is less than one fifth of the beam length. These conclusions provide references for how to design and layout the stiffening ribs when designing thin-walled box beam in restrained torsion in the practical construction.

e15585 Background: With the unprecedented morbidity and mortality associated with the COVID-19 pandemic, vaccine against COVID-19 has been more and more popularized in general population. However, the safety of COVID-19 vaccine injection in patientswith malignant tumors, such as colorectal cancer (CRC), remains unclear. Methods: During January 2021 and January 2022, 148 CRC patients treated in the department of colorectal surgery in the Sixth Affiliated Hospital of Sun Yat-sen University were enrolled in this cohort. The clinical data and COVID-19 vaccine injection outcome data was collected and analyzed retrospectively. Patients who received at least one dose of COVID-19 vaccine injection were set as an observation group and those who did not get any vaccine injection were set as a control group. The median follow-up time was 8.0 months, vaccine-related adverse events (VRAEs) were collected by questionnaire. The disease progression status of CRC was also compared between the two groups. Results: Eighty-three CRC (male: female 44:39) patients enrolled in this study have got at least one dose of COVID-19 vaccine injection, with a median follow-up time of 8.0 (2.0–13.0) months and no VRAEs reported. Among the vaccinated patients, 51 patients were injected with inactivated vaccine (Sinovac Life Sciences Co., Ltd.), 10 patients were vaccinated with inactivated vaccine (Beijing Institute of Biological Products Co., Ltd.), others were injected another inactivated vaccine (Chengdu Institute of Biological Products Co., Ltd.). The reasons of the 65 patients (male: female 36:29) who did not injected COVID-19 vaccine including: 53 patients had a concern that vaccination will affect the progress of CRC, 8 patients had a concern of old age to get vaccinated and 4 patients did not give any reason. As for disease progression, 14 patients in the observation group had tumor recurrence or progression, while 8 patients in control group reported tumor recurrence or progression, with a median follow-up time of 8.0 (2.0–13.0) months. There was no significant difference in short-term disease progression between the observation group and the control group (P = 0.439). Conclusions: Under the background of COVID-19 pandemic and vaccination of general population, it might be necessary for the patients with malignant disease, such as CRC, to get vaccinated due to whose weaken immune system. COVID-19 vaccine injection is safe for CRC patients and COVID-19 vaccination would not affect the patients’ prognosis.