[Epidemiological characteristics of COVID-19 in Wuchang district of Wuhan]

Objective: To analyzes epidemiological characteristics of COVID-19 and provide evidence for adjustment for COVID-19 prevention and control strategies. Methods: The data of COVID-19 cases in Wuchang district reported as of 19 March, 2020 were obtained from National Notifiable Disease Report System of Chinese Disease Prevention and Control Information System. The software's of Excel 2010, SPSSS 22.0, Arc GIS10.2 and Joinpoint regression program 4.8.0.0 were used for statistical analysis. Results: A total of 7547 COVID-19 cases had been reported as of 19 March, 2020 in Wuchang district, including 5 448 confirmed cases (72.19%), 2009 clinical diagnosed cases (26.62%) and 90 asymptomatic cases case (1.19%). The age of the cases was (56.65±16.25) years and age ranged from 2 days to 105 years among confirmed cases, 2634 were males (48.35%) and 2814 were females (51.65%), 2 492 were retirees (45.74%). A total of 545 health workers were infected with SARS-CoV-2 (7.22% of all cases) including 365 confirmed cases and 5 cases have died. A total of 430 cases of death were reported with case fatality rate of 7.89% (430/5 448), case fatality rate of males (10.9%, 266/2 634) was higher than that of females (5.82%, 164/2 814). The first phase of epidemic peak was from January 24 to January 26, the second phase of epidemic peak was from February 1 to February 5 and there was no one of new confirmed case in one day for the first time on March 18. The first four Streets with the highest incidence rates of confirmed cases were Huanghelou Street (1 043.77/100 000), Ziyang Street (627.97/100 000), Yangyuan Street (503.67/100 000) and Shuiguohu Street (486.02/100 000). Compared with females, aged ≤50 years and mild cases of clinical classification respectively, males (RR=0.690, 95%CI: 0.322-1.478), aged >50 years (RR=11.745, 95%CI: 6.878-20.058), severe cases (RR=2.317, 95%CI: 1.789-3.000) and critical cases of clinical classification (RR=10.794, 95%CI: 7.997-14.569), and gender time-dependent covariate (RR=1.392, 95%CI: 1.053-1.840) were major influencing factors of prognosis of COVID-19 confirmed cases. Conclusions: The gender, ages and occupation of distribution were wide among COVID-19 cases in Wuchang district. Males, aged >50 years, severe cases and critical cases of clinical classification were influencing factors of prognosis of COVID-19 confirmed cases. The standardized management of discharged cases, asymptomatic infected cases and close contact persons were main measures to reduce incidence rates of COVID-19 cases.

Nomogram predicting early neurological improvement in ischaemic stroke patients treated with endovascular thrombectomy

BACKGROUND AND PURPOSE

Early neurological improvement (ENI) after endovascular thrombectomy (EVT) has been associated with favorable outcomes. This study aimed to identify the optimal definition of ENI and develop a nomogram for predicting ENI after EVT in acute ischaemic stroke.

METHODS

Patients with EVT were enrolled from a multicenter registry as the training cohort. The receiver operating characteristic curve was used to estimate the optimal threshold for ENI at 24 h of EVT. Logistic regression analysis was utilized to generate the best-fit nomogram for predicting ENI. The discrimination of the nomogram was assessed using the area under the receiver operating characteristic curve (AUC). An additional 447 patients from two stroke centers were prospectively recruited as the test cohort for validating the nomogram.

RESULTS

A total of 612 patients with EVT were included in the training cohort. The optimal threshold for predicting 3-month favorable outcome (modified Rankin Scale 0-2) was an improvement of the National Institutes of Health Stroke Scale (NIHSS) score by ≥6 points (AUC 0.875; sensitivity 79.5%; specificity 90.7%). Age, blood glucose, recanalization, symptomatic intracranial hemorrhage (sICH) and baseline Alberta Stroke Program Early Computed Tomography Score (ASPECTS) were independently associated with ENI, and were incorporated in the nomogram. The AUC of the nomogram was 0.795 in the training cohort and 0.752 in the test cohort.

CONCLUSIONS

A reduction of NIHSS score ≥6 appeared to be the optimal definition of ENI. The nomogram composed of age, blood glucose, recanalization, sICH and baseline ASPECTS may predict the probability of ENI in ischaemic stroke patients treated with EVT.

Combination of pegylated interferon-alpha and nucleos(t)ide analogue treatment enhances the activity of natural killer cells in nucleos(t)ide analogue experienced chronic hepatitis B patients

A combination of pegylated interferon-alpha (peg-IFN-α) and nucleos(t)ides analogue (NA) therapy can effectively reduce hepatitis B surface antigen (HBsAg), especially in NA-experienced chronic hepatitis B (CHB) patients. However, the immune mechanism of this therapy is unclear. Forty NA-experienced CHB patients were enrolled into this study. The frequencies of peripheral blood natural killer (NK) cells, dendritic cells (DCs), CD4⁺ T cells, CD8⁺ T cells, T helper (Th) cells, regulatory T cells (T_reg ), B cells and follicular T helper (Tfh) cells were evaluated by flow cytometry. Seven of the 40 patients converted to peg-IFN-α combined with NA treatment, while the other 33 continued to NA therapy. The decrease in HBsAg was more pronounced in the combination treatment group, and only patients receiving combination treatment achieved HBsAg loss. The frequency and absolute number of CD56^bright NK cells in the combination treatment group increased significantly compared with the NA treatment group, whereas the CD56^dim NK cells were decreased. In the NA treatment group, the proportions of CD4⁺ T_N , CD8⁺ T_N , CD19⁺ B and cytotoxic T lymphocyte antigen-4 (CTLA-4)⁺ CD4⁺ T cells were increased, while the proportions of CD4⁺ T_EM , CD8⁺ T_EM , CD25⁺ CD4⁺ T_reg , CD25^high CD4⁺ T_reg , CD127^low CD25⁺ T_reg , programmed cell death 1 (PD-1)⁺ CD4⁺ T, PD-1⁺ CD8⁺ T, CTLA-4⁺ CD8⁺ T, CCR4⁺ CD25⁺ T_reg and CCR4⁺ CD25^high T_reg cells were decreased after therapy. For NA-experienced CHB patients who achieved low HBsAg levels, combination treatment is more likely to result in HBsAg decline and HBsAg clearance by increasing the activity of CD56^bright NK cells.

Long non-coding RNA HOTAIR regulates the development of non-small cell lung cancer through miR-217/DACH1 signaling pathway

OBJECTIVE

Long non-coding RNA HOX transcript antisense RNA (HOTAIR) is reported to make chromatin state, cell growth and cancer metastasis. However, the role of HOTAIR in non-small cell lung cancer (NSCLC) remains unknown. The aim of this study was to explore the regulatory mechanism of HOTAIR in NSCLC in relation to miR-217/Dachshund homolog 1 (DACH1) signaling pathway.

MATERIALS AND METHODS

The expression levels of HOTAIR and miR-217 were measured by quantitative Polymerase Chain Reaction (qPCR) in NSCLC cell lines and human bronchial epithelial cell line HBE. The direct target of HOTAIR and miR-217 in NSCLC was confirmed by a Luciferase reporter assay. The expression of DACH1 protein was examined by Western blot (WB) assay. Cell migration and invasion were examined with transwell assays, and cell proliferation was measured by Cell Counting Kit-8 (CCK8) assay.

RESULTS

HOTAIR was up-regulated and miR-217 was down-regulated in NSCLC cell lines. Silencing of HOTAIR significantly repressed cell proliferation and inhibited cell migration and invasion in H1299 and A549 cells by facilitating miR-217 expression. Moreover, bioinformatics analysis and Luciferase reporter assay confirmed that DACH1 was a target of miR-217. Furthermore, the overexpression of miR-217 markedly repressed cell proliferation and inhibited cell migration and invasion in H1299 and A549 cells. DACH1 reverses the effects of miR-217 overexpression in NSCLC cells.

CONCLUSIONS

HOTAIR was up-regulated in NSCLC cell and regulates the proliferation, migration, invasion through the miR-217/DACH1 signaling pathway. It provides a novel potential treatment strategy for NSCLC.

[The differential diagnosis for novel coronavirus pneumonia and similar lung diseases in general hospitals]

Novel coronavirus pneumonia was a novel coronavirus infection that has dominated pulmonary infection since December 2019. The main manifestations were fever, dry cough, shortness of breath, normal or leukopenia in peripheral blood and changes in chest CT and in severe cases, multiple organ failure might occur. The National Health Commission, PRC has revised the consensus on diagnosis and treatment seven times in a short period of time, indicating the growing understanding of the disease. Patients with novel coronavirus pneumonia usually had history of travelling or living in the epidemic area including Wuhan within 14 days before onset, or have been exposed to patients who had fever or respiratory symptoms from the epidemic area, or had clustering diseases. However, novel coronavirus pneumonia was becoming more and more blurred after vanishing epidemic. The diagnosis and differential diagnosis of novel coronavirus pneumonia were challenges not only because of large number of tourists increasing dramatically after the relieving of epidemic, but also patients with other diseases from different areas to search for medical care. In this article, the clinical and chest imaging features of the novel coronavirus pneumonia were reviewed and compared with other infections and non-infectious diffuse pulmonary diseases. We try to find the similarities and differences among them, and to identify clues to the diagnosis of novel coronavirus pneumonia, so as to ensure accurate diagnosis and treatment.

[The clinical features and prognosis of interstitial lung disease patients with positive anti-neutrophil cytoplasmic antibody]

Objective: To investigate the clinical features and prognosis of interstitial lung disease patients with positive anti-neutrophil cytoplasmic antibody. Methods: The patients with interstitial lung disease who visited Peking Union Medical College Hospital from March 2006 to March 2016 were divided into three groups: interstitial lung disease with ANCA-positive(ANCA-ILD), connective tissue disease associated interstitial lung disease and interstitial pneumonia with autoimmune features (CTD-ILD/IPAF) and idiopathic interstitial pneumonia (IIP). The three groups were analyzed in terms of clinical manifestations, serology, lung function, imaging, survival and recurrence. Results: Two hundred and seventy four patients were enrolled and 38 (14%) were ANCA-positive of whom 16 were male and 22 were female. The age of 38 ANCA-positive patients was (59±10) years and the follow-up time was (52±31) months. Seven among the 38 ANCA-positive patients died and the death rate is 18.42%. The ANCA-positive patients with interstitial lung disease have higher onset age (ANCA-ILD:59±10,CTD-ILD/IPAF:52±10,IIP:53±11,H=19.29, P<0.001), lower hemoglobin (ANCA-ILD: 129±21, CTD-ILD/IPAF: 138±15, IIP: 140±19, H=8.17, P=0.017), higher erythrocyte sedimentation rate (ANCA-ILD:45±35, CTD-ILD/IPAF:26±24,IIP:19±22,H=19.73, P<0.001), lower lung function improvement rate after treatment (ANCA-ILD:31%,CTD-ILD/IPAF:59%,IIP: 39%,χ(2)=11.74,P=0.003), lower absorption rate of CT lesion (ANCA-ILD:61%,CTD-ILD/IPAF:82%,IIP:67%, χ(2)=9.23,P=0.010) and higher death rate(ANCA-ILD:18%,CTD-ILD/IPAF:6%,IIP:12%, χ(2)=7.16,P=0.028). Conclusions: There are significant differences in clinical characteristics between ANCA-positive patients and other types of pulmonary interstitial disease. And both the treatment effect and the prognosis is poor for the ANCA-positive patients.

A decision-making method based on Bayesian optimization algorithm for small modular reactor

Small modular reactors (SMRs) are suitable for deployment in isolated underdeveloped areas to support highly localized microgrids. In order to achieve almost autonomous operation for reducing the cost of operating personnel, an autonomous control system with decision-making capability is needed. In this paper, a decision-making method based on Bayesian optimization algorithm (BOA) is proposed to explore the optimal operation scheme under fault conditions. BOA is used to adjust exploration strategy of operation scheme according to observations (operation schemes previously explored). To measure the feasibility of each operation scheme, an objective function that considers security and economy is established. BOA attempts to obtain the optimal operation scheme with maximum of the objective function in as few iterations as possible. To verify the proposed method, all main pump powered off fault is simulated by RELAP5 code. The optimal operation scheme of the fault is applied, the transient result shows that all key parameters are within safe limits and SMR is maintained at relatively high power, which means that BOA has the decision-making capability to get an optimal operation scheme on fault conditions.

Dietary Inflammatory Index and Leukoaraiosis in Patients with Ischemic Stroke

OBJECTIVES

Diet may change the chronic levels of systemic inflammation, which in turn influence the development of leukoaraiosis (LA). This study aimed to examine the association between dietary inflammatory index (DII) and LA in patients with ischemic stroke.

METHODS

Patients with first-ever ischemic stroke were enrolled from two centers. A semi-quantitative food frequency questionnaire (FFQ) was used to evaluate diet contents. The DII score of each patient was calculated based on the reported diet contents. Presence and degree of LA were evaluated with a magnetic resonance imaging (MRI) scan. LA was graded according to Fazekas scale.

RESULTS

Of the 497 enrolled patients, 337 (67.8%) were detected with LA. Patients with LA had a higher DII score (0.23 vs -0.88, P < 0.001). Logistic regression analysis detected that patients with highest quartile of DII score had an OR of 3.61 (95% CI: 2.05-6.36, P < 0.001) for LA compared with those with lowest quartile of DII. After adjusting for major confounders, the highest DII quartile remained as an independent predictor for LA (OR = 2.66, 95% CI: 1.41-5.00, P = 0.008).

CONCLUSIONS

A pro-inflammatory diet pattern, as indicated by higher DII values, appears to be associated with a higher risk of LA. This result suggested that dietary-mediated inflammation may involved in the pathogenesis of LA, which warrant further study.

Evolutionary adaptation of Aspergillus niger for increased ferulic acid tolerance

AIMS

To create an Aspergillus niger mutant with increased tolerance against ferulic acid using evolutionary adaptation.

METHODS AND RESULTS

Evolutionary adaptation of A. niger N402 was performed by consecutive growth on increasing concentrations of ferulic acid in the presence of 25 mmol l^-1 d-fructose, starting from 0·5 mmol l^-1 and ending with 5 mmol l^-1 ferulic acid. The A. niger mutant obtained after six months, named Fa6, showed increased ferulic acid tolerance compared to the parent. In addition, Fa6 has increased ferulic acid consumption and a higher conversion rate, suggesting that the mutation affects aromatic metabolism of this species. Transcriptome analysis of the evolutionary mutant on ferulic acid revealed a distinct gene expression profile compared to the wild type. Further analysis of this mutant and the parent strain provided the first experimental confirmation that A. niger converts coniferyl alcohol to ferulic acid.

CONCLUSIONS

The evolutionary adaptive A. niger mutant Fa6 has beneficial mutations that increase the tolerance, conversion rate and uptake of ferulic acid.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrates that evolutionary adaptation is a powerful tool to modify micro-organisms towards increased tolerance to harsh conditions, which is beneficial for various industrial applications.

A case of intracranial molluscum contagiosum virus infection diagnosed by metagenomic sequencing of cerebrospinal fluid

Molluscum contagiosum is a common, self-limiting infectious disease of the skin caused by molluscum contagiosum virus (MCV). The disease primarily affects children, sexually active adults, and immunocompromised individuals. Transmission of the virus occurs by direct skin contact. Therefore, the virus is usually detected in the skin and genitals of patients. However, the diagnosis of intracranial infection by the virus is difficult if the skin/mucosa lessons are atypical or absent, and the presence of the virus in the cerebrospinal fluid has not been reported. We report a very rare case of intracranial infection by molluscum contagiosum virus. A 25-year-old girl was admitted to our hospital due to severe headache but no fever or other symptoms. Upon examination, some small flesh-colored flattened papules on both arms were noticed. Blood tests showed slightly reduced levels of CD3 and CD4 T lymphocytes. Three-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) and head magnetic resonance (MR) were both normal. Lumbar puncture was performed, and metagenomic sequencing was applied to the spinal fluid. The unique sequences of the molluscum contagiosum virus were identified in the fluid. The patient was then diagnosed with intracranial molluscum contagiosum virus infection. No special treatment was given. The headache gradually disappeared, and the patient was discharged. During our quarterly follow-up, the girl appeared normal, and her skin lesions disappeared. However, her CD3 and CD4 T lymphocyte counts were still slightly lower than the normal level. Our case shows that the application of metagenomic sequencing to cerebrospinal fluid is a sensitive and powerful means to detect pathogens causing intracranial infection. Keywords: Molluscum contagiosum; intracranial infection; metagenomics sequencing.

Coupling simulation of neutron kinetics core model with CFD of IPWR steam line break accident

In this paper, development of coupled codes using two-group neutron diffusion kinetics code and computational fluid dynamics (CFD) solver Fluent has been introduced. Way of coupling, time step control algorithm and spatial mesh overlays have been summarized in detail which are basic components and challenges of the coupling methodologies. The implement and verification of coupled code have been modeled on integral pressurized water reactor (IPWR) IP200 with hexagonal fuel assembly in the core and once-through steam generators. The steam line break core transient was analyzed in coupled code simulation of a core boundary conditions derived from system code simulation results. The results presented transient three-dimensional distribution of the key operation parameters such as reactor power and coolant temperature, also demonstrated the inherent safety features of IP200. The current work will bring about the ability to explore multi-scale and multi-dimensional safety transient evaluations and give more precise neutronics/thermal-hydraulics mapping.

Analysis of operating characteristics of IPWR under natural circulation

Many integrated pressurized water reactor (IPWR) designs using natural circulation operation mainly to enhance their inherent safety. The operating characteristics of primary coolant are completely different without mechanical pumps. The designs and safety analysis of forced circulation reactors are widely researched, but the natural circulation characteristics of IPWR have not been well studied by literatures. The present work discussed the thermal-hydraulic characteristics of IPWR under natural circulation conditions by using the best estimate codes RELAP5. And the effect of system parameters on natural circulation characteristics of IPWR is also studied. The results show that, the primary coolant average temperature and steam pressure are two key parameters that affect the natural circulation stable operating load. The set value of primary coolant average temperature effects the core outlet temperature and the steam temperature, but the primary coolant flow is basically the same under different primary coolant average temperature but same load conditions. The smaller steam pressure is more conducive to produce superheated steam, but there is risk of two phase flow instability in OTSG secondary side. The rapid load change process under natural circulation indicating that the reactor has a good load tracking characteristics under natural circulation, but the rapid change of primary coolant temperature will cause oscillations in system parameters.

Genomic and exoproteomic diversity in plant biomass degradation approaches among Aspergilli

We classified the genes encoding carbohydrate-active enzymes (CAZymes) in 17 sequenced genomes representing 16 evolutionarily diverse Aspergillus species. We performed a phylogenetic analysis of the encoding enzymes, along with experimentally characterized CAZymes, to assign molecular function to the Aspergilli CAZyme families and subfamilies. Genome content analysis revealed that the numbers of CAZy genes per CAZy family related to plant biomass degradation follow closely the taxonomic distance between the species. On the other hand, growth analysis showed almost no correlation between the number of CAZyme genes and the efficiency in polysaccharide utilization. The exception is A. clavatus where a reduced number of pectinolytic enzymes can be correlated with poor growth on pectin. To gain detailed information on the enzymes used by Aspergilli to breakdown complex biomass, we conducted exoproteome analysis by mass spectrometry. These results showed that Aspergilli produce many different enzymes mixtures in the presence of sugar beet pulp and wheat bran. Despite the diverse enzyme mixtures produced, species of section Nigri, A. aculeatus, A. nidulans and A. terreus, produce mixtures of enzymes with activities that are capable of digesting all the major polysaccharides in the available substrates, suggesting that they are capable of degrading all the polysaccharides present simultaneously. For the other Aspergilli, typically the enzymes produced are targeted to a subset of polysaccharides present, suggesting that they can digest only a subset of polysaccharides at a given time.

Multicentric Evaluation of a New PT Reagent Based on Recombinant Human Tissue Factor and Synthetic Phospholipids

A new PT reagent based on recombinant human tissue factor and synthetic phospholipids (phosphatidyl choline and phosphatidyl serine) with defined fatty acid side chains was calibrated against BCT/253 and CRM 149R. A small but consistent bias in the International Sensitivity Index (ISI) value was obtained using either the human or rabbit brain reference material. ISI values were around 1.0 or slightly lower depending on the respective instrument. Mixing studies with factor deficient plasmas showed a high factor sensitivity especially for factor VII as compared to commercial rabbit brain or human placenta thromboplastin. In an international field trial the reagent was tested using fully or semi automated Electra™ coagulometers in 4 different laboratories. Results with normal samples were in excellent agreement among the different laboratories. Mean values were 10.9, 10.9, 11.0, 11,7 s with a range of 9.5 to 12.5 s. Results of males and females were not different. In patients with liver disease very similar PT activities were found as compared to sensitive rabbit brain or human placental thromboplastins. In normals and patients with oral anticoagulation INR values correlated very well against BCT (r = 0.98, regression line y =-0.07 + 0.9 x). The distribution of samples was linear over the whole range. In the comparison against sensitive rabbit brain thromboplastin or human placental thromboplastin similar correlations were found. In a few cases higher INR values were observed for the recombinant reagent especially in patients with intensive treatment. Factor assays in those patients showed at least the strong reduction of one vitamin Independent coagulation factor. Over all the linearity was better against the rabbit brain reagent than against the human placental reagent which is slightly less factor VII sensitive as shown in mixing studies with normal and factor VII deficient plasma. Precision studies in the 4 laboratories showed excellent reproducibility of lyophilised controls or local patient plasma pools for all reagents with a better performance of the recombinant reagent. C. V. values from day to day ranged from 1.3% to 5% for normal and abnormal controls.

These results show that the recombinant PT reagent, especially in conjunction with a precise automated instrument, may improve the results of PT testing and thus may lead to better patient care.

Stable actively Q-switched single-frequency fiber laser at 1.5 μm based on self-injecting polarization modulation

A new technique for the realization of a stable Q-switched operation in a single-frequency fiber laser based on self-injecting polarization modulation is demonstrated, for the first time to the best of our knowledge. A piezoelectric fiber stretcher was utilized to introduce periodic stress-induced polarization changes. Then the modulation of polarization state transformed into Q switching by virtue of a designed distributed Bragg reflector (DBR) resonant cavity with polarizations loss anisotropy. Finally, a stable actively Q-switched single-frequency fiber laser at 1.5 μm with Gaussian-shape pulse output was achieved. We experimentally found that, the repetition frequency (several hundred kHz) coincided with the working frequency of the polarization modulation, and the pulse width (several hundred ns) reduced with the increasing of the modulating frequency, the modulating amplitude, as well as the pump power. This stable Q-switched single-frequency fiber laser is promising for applications in optical time-domain reflectometry, coherent Doppler wind radar, and optical coherent detection. More importantly, this novel Q-switched technology may be applicable to other DBR single-frequency fiber lasers.