The recombinant Erns and truncated E2-based indirect enzyme-linked immunosorbent assays to distinguishably test specific antibodies against classical swine fever virus and bovine viral diarrhea virus.

BACKGROUND: Classical swine fever (CSF) virus is the causative agent of an economically important, highly contagious disease of pigs. CSFV is genetically and serologically related to bovine viral diarrhea virus (BVDV). BVDV infection in pigs can mimic CSF clinical signs, which cause difficulty in differentiation. Serological test for detection of virus specific antibodies is a valuable tool for diagnosis and surveillance of CSFV and BVDV infections in animals. The aim of this study was to develop the CSFV Erns and BVDV tE2 -based ELISAs to distinguishably test specific antibodies against CSFV and BVDV. METHODS: The CSFV Erns and truncated E2 (tE2, residues 690-865) of BVDV were expressed in E. coli and purified by Ni-NTA affinity chromatography, respectively. Employing Erns or tE2 protein as diagnostic antigen, indirect ELISAs were developed to distinguishably test specific antibodies against CSFV and BVDV. The specificity and sensitivity of ELISAs were evaluated using a panel of virus specific sera of pigs, immunized rabbits and immunized mice. A total 150 clinical serum samples from farm pigs were measured by the developed ELISAs and compared with virus neutralizing test (VNT). RESULTS: Indirect ELISA was established based on recombinant CSFV Erns or BVDV tE2 protein, respectively. No serological cross-reaction between antibodies against CSFV and BVDV was observed in sera of immunized rabbits, immunized mice or farm pigs by detections of the Erns and tE2 -based ELISAs. Compared to VNT, the CSFV Erns -based ELISA displayed a high sensitivity (93.3%), specificity (92.0%) and agreement rate (92.7%), and the sensitivity, specificity and agreement rate of BVDV tE2 -based ELISA was 92.3%, 95.2% and 94.7%, respectively. CONCLUSION: The newly developed ELISAs are highly specific and sensitive and would be valuable tools for serological diagnosis for CSFV and BVDV infections.

Role of the conserved E2 residue G259 in classical swine fever virus production and replication.

The E2 glycoprotein of classical swine fever virus (CSFV) plays multiple roles in the viral life cycle. The chimeric live attenuated C strain with the E2 substitution of bovine viral diarrhea virus (BVDV) is a promising marker vaccine candidate. In this study, the recombinant chimeric CSFV/bE2 cDNA clone harboring heterologous E2 (bE2) of BVDV was constructed by genetic approaches. Recombinant infectious virus rCSFV/bE2 (P11) was recovered by 11 serial passages of transfected PK15 cells. Viral genome sequencing showed that a glutamic acid to glycine mutation (E260G) at position 260 of the bE2 was observed in rCSFV/bE2 P11. Alignment of amino acid sequences displayed that the glycine was one of three conserved residues in pestivirus E2. When the glutamic acid to glycine substitution (E260G) was introduced into chimeric CSFV/bE2 cDNA clone, the high-titer infectious rCSFV/bE2E260G was rescued. The glycine to glutamic acid substitution at corresponding position in CSFV E2 resulted in significantly decreased rCSFV/E2G259E production. We further identified that the conserved E2 residue G259 played a critical role in the release and binding activity of CSFV and that the E2 residues G259 and V111 modulated synergistically infectious virus production and replication.

Revealing the Synergistic Deactivation Mechanism of Hydrothermal Aging and SO2 Poisoning on Cu/SSZ-13 under SCR Condition.

In real-world application, Cu/SSZ-13 simultaneously suffers severe deactivation from hydrothermal aging and SO2 poisoning during the periodic regeneration of diesel particulate filter (DPF). Herein, we first investigated the synergistic deactivation mechanism of hydrothermal aging and SO2 poisoning on Cu/SSZ-13 under SCR condition. Hydrothermal aging alone induces more severe degradation of selective catalytic reduction (SCR) performance than SO2 poisoning alone, while the presence of SO2 during hydrothermal aging causes further worse SCR performance compared with hydrothermal aging alone. Hydrothermal aging not only damages Si-OH-Al sites, particularly in four-membered ring (4MR) of the CHA cage, but also brings the conversion of ZCuOH, leading to the formation of inactive CuO/CuAlOx species. By contrast, SO2 poisoning alone is more prone to promote the transformation of ZCuOH to Z2Cu. Synergistic deactivation of hydrothermal aging and SO2 poisoning would exacerbate the damage of Si-OH-Al sites and then the formation of CuO/CuAlOx species. These results are expected to assist the knowledge-based catalyst design for diesel aftertreatment applications.

Super-resolution of Pneumocystis carinii pneumonia CT via self-attention GAN.

BACKGROUND AND OBJECTIVE: Computed tomography (CT) examination plays an important role in screening suspected and confirmed patients in pneumocystis carinii pneumonia (PCP), and the efficient acquisition of high-quality medical CT images is essential for the clinical application of computer-aided diagnosis technology. Therefore, improving the resolution of CT images of pneumonia is a very important task. METHODS: Aiming at the problem of how to recover the texture details of the reconstructed PCP CT super-resolution image, we propose the image super-resolution reconstruction model based on self-attention generation adversarial network (SAGAN). In the SAGAN algorithm, a generator based on self-attention mechanism and residual module is used to transform a low-resolution image into a super-resolution image. A discriminator based on depth convolution network tries to distinguish the difference between the reconstructed super-resolution image and the real super-resolution image. In terms of loss function construction, on the one hand, the Charbonnier content loss function is used to improve the accuracy of image reconstruction, and on the other hand, the feature value before activation of the pre-trained VGGNet is used to calculate the perceptual loss to achieve accurate texture detail reconstruction of super-resolution images. RESULTS: Experimental results show that our SAGAN algorithm is superior to other state-of-the-art algorithms in both peak signal-to-noise ratio (PSNR) and structural similarity score (SSIM). Specifically, our SAGAN method can obtain 31.94 dB which is 1.53 dB better than SRGAN on Set5 dataset for 4 enlargements. CONCLUSION: Our SAGAN method can reconstruct more realistic PCP CT images with clear texture, which can help experts diagnose the condition of PCP.

A positively charged surface patch on the pestivirus NS3 protease module plays an important role in modulating NS3 helicase activity and virus production.

Pestivirus nonstructural protein 3 (NS3) is a multifunctional protein with protease and helicase activities that are essential for virus replication. In this study, we used a combination of biochemical and genetic approaches to investigate the relationship between a positively charged patch on the protease module and NS3 function. The surface patch is composed of four basic residues, R50, K74 and K94 in the NS3 protease domain and H24 in the structurally integrated cofactor NS4APCS. Single-residue or simultaneous four-residue substitutions in the patch to alanine or aspartic acid had little effect on ATPase activity. However, single substitutions of R50, K94 or H24 or a simultaneous four-residue substitution resulted in apparent changes in the helicase activity and RNA-binding ability of NS3. When these mutations were introduced into a classical swine fever virus (CSFV) cDNA clone, a single substitution at K94 or a simultaneous four-residue substitution (Qua_A or Qua_D) impaired the production of infectious virus. Furthermore, the replication efficiency of the CSFV variants was partially correlated with the helicase activity of NS3 in vitro. Our results suggest that the conserved positively charged patch on NS3 plays an important role in modulating the NS3 helicase activity in vitro and CSFV production.

Association of Ang-2, vWF, and EVLWI with risk of mortality in sepsis patients with concomitant ARDS: A retrospective study.

BACKGROUND/PURPOSE: This study aimed to determine the potential effects of angiopoietin-2 (Ang-2), von Willebrand factor (vWF), and extravascular lung water index (EVLWI) on the risk of mortality in sepsis patients with concomitant acute respiratory distress syndrome (ARDS). METHODS: This retrospective study recruited 41 sepsis patients with concomitant ARDS from January 2015 to June 2018. Data of Ang-2 and vWF levels, EVLWI, and sequential organ failure assessment scores were collected at 0, 24, and 48 h after admission to the hospital. RESULTS: The length of intensive care unit stay (P = 0.041) and Acute Physiology and Chronic Health Evaluation-2 (APACHE II) score (P = 0.003) were associated with the risk of mortality. Furthermore, increased Ang-2 levels and EVLWI at 24 h and 48 h were associated with an increased risk of mortality. Moreover, the APACHE II score at hospital admission significantly predicted the risk of mortality (area under the curve [AUC], 0.834; 95% confidence interval [CI], 0.665-0.983). Finally, the models containing a combination of Ang-2 level and EVLWI at 24 h (AUC, 0.908; 95% CI, 0.774-0.996) and Ang-2 level and EVLWI at 48 h (AUC, 0.981; 95% CI, 0.817-1.000) had high diagnostic values for predicting risk of mortality. CONCLUSION: The study findings indicate that Ang-2 levels and EVLWI at 24 h and 48 h after admission are significantly associated with the risk of mortality.

Efficacy and safety of individually tailored antiplatelet therapy in patients with acute coronary syndrome after coronary stenting: a single center, randomized, feasibility study.

BACKGROUND: Low responsiveness to clopidogrel (LRC) is associated with increased risk of ischemic events. This study was aimed to explore the feasibility of tailored antiplatelet therapy according to the responsiveness to clopidogrel. METHODS: A total of 305 clopidogrel naïve patients with acute coronary syndromes (ACS) undergoing coronary stenting were randomly assigned to receive standard (n = 151) or tailored (n = 154) antiplatelet therapy. The ADP-induced platelet aggregation tests by light transmission aggregometry were performed to identify LRC patients assigned to the tailored group. The standard antiplatelet regimen was dual antiplatelet therapy with aspirin and clopidogrel. The tailored antiplatelet therapy was standard regimen for non-LRC patients and an additional 6-month cilostazol treatment for LRC patients. The primary efficacy outcome was the composite of cardiovascular death, myocardial infarction or stroke at one year. RESULTS: LCR was present in 26.6% (41/154) of patients in the tailored group. The percentage platelet aggregation for LCR patients was significantly decreased at three days after adjunctive cilostazol treatment (77.5% ± 12.1% vs. 64.5% ± 12.1%, P < 0.001). At one year follow-up, a non-significant 37% relative risk reduction of primary events were observed in the tailored group as compared to the standard group (5.8% vs. 9.3%, P = 0.257). There were no differences in the rates of stent thrombosis and hemorrhagic events between the two groups. CONCLUSIONS: Tailored antiplatelet therapy for ACS patients after coronary stenting according to responsiveness to clopidogrel is feasible. However, its efficacy and safety need further confirmation by clinical trials with larger sample sizes.