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Antibiotic resistance is currently a world health crisis that urges the development of new antibacterial substances. To this end, natural products, including flavonoids, alkaloids, terpenoids, steroids, peptides and organic acids play a vital role in the development of medicines and thus constitute a rich source in clinical practices, providing an important source of drugs directly or for the screen of lead compounds for new antibiotic development. Because membrane proteins, which comprise more than 60% of the current clinical drug targets, play crucial roles in signal transduction, transport, bacterial pathogenicity and drug resistance, as well as immunogenicity, it is our aim to summarize those natural products with different structures that target bacterial membrane proteins, such as efflux pumps and enzymes, to provide an overview for the development of new antibiotics to deal with antibiotic resistance.

BACKGROUND: Measles is a highly-contagious, serious diseases that can lead to potentially fatal illness, disability and death . We conducted an investigation to calculate the economic burden of measles cases from 2018 to 2019 and to analyze factors that influenced the total costs of measles cases in Fujian Province, China. METHODS: We investigated confirmed cases of measles by telephone interview, from 2018 to 2019, including demographic characteristics, therapeutic measures, self-treatment and nutritional supplement expenditure, transportation fees, and lost wages. Medical expenses in the hospitals were obtained from the hospital service charge system. RESULTS: A total of 131 measles cases were investigated, the average direct cost, indirect cost, and total cost were $518, $284, and $802, respectively. The total cost was 15.5% of Annual Per Capita Disposable Income of Households ($5 162) in Fujian. Hospitalization (OR = 98.6, 95%CI: 21.1 ~ 460.6) and complication (OR = 8.7, 95%CI: 1.3 ~ 58.0) significantly influenced the total cost according to binary logistic regression, and an outbreak of measles may pose a significant threat to household finances in a short term. CONCLUSIONS: The economic burden of measles was high when compared with Annual Per Capita Disposable Income of Households. The resurgence of measles and measles outbreaks increased economic burden of household finances.

Nanotube can be used as a mass sensor. To design a mass sensor for evaluating a high-speed nanoparticle, in this study, we investigated the impact vibration of a cantilever nanobeam being transversally collided by a high-speed C60 at the beam's free end with an incident velocity of vIn. The capped beam contains alternately two boron nitride zones and two carbon zones on its cross section. Hence, the relaxed beam has elliptic cross section. The vibration properties were demonstrated by molecular dynamics simulation results. Beat vibration of a slim beam can be found easily. The 1st and the 2nd order natural frequencies (f1 and f2) of the beam illustrate the vibration of beam along the short and the long axes of its elliptic cross section, respectively. f2 decreases with increasing temperature. A minimal value of vIn leads to the local buckling of the beam, and a different minimal vIn leading to damage of the beam. For the same system at a specified temperature, f2 varies with vIn. When the beam bends almost uniformly, f2 decreases linearly with vIn. If vIn becomes higher, the beam has a cross section which buckles locally, and the buckling position varies during vibration. If vIn approaches the damage velocity, a fixed contraflexture point may appear on the beam due to its strong buckling. Above the damage velocity, f2 decreases sharply. These results have a potential application in design of a mass sensor.

Here, we report the identification of Histoplasma causing an unexplained disease cluster in Matthews Ridge, Guyana. In March 2019, 14 employees of Chongqing Bosai Mining Company, China, working in a manganese mining of Guyana, had unexplained fever, and two of them died. We obtained lung and brain tissues as well as the blood samples from the two deceased cases (patient No. 1 and 2), and bronchoscopy lavages and cerebrospinal fluid samples from one severe case (patient No. 3), respectively. All samples were tested by pathological examination, high-throughput sequencing, and real-time PCR. Pathological detection showed the presence of spore-like structures in the lung tissue of patient No. 1, indicating a fungal infection in this patient. Nanopore sequencing identified the existing of H. capsulatum in the lung tissue sample within 13 h. Next-generation sequencing identified specific fragments of H. capsulatum in all of the samples tested (lung, brain and blood serum from the deceased cases, and plasma from the severe case). Real-time PCR assays did not reveal any viral infection related to transmission from bat feces. We conclude that H. capsulatum was the causative pathogen of this disease cluster based on epidemiologic, clinical, pathological and nucleic acid evidence., Highlights • Scientific question This study reported the identification of Histoplasma as the cause of an unexplained disease cluster in Matthews Ridge, Guyana. • Evidence before this study In March 2019, 14 Chinese employees from Chongqing Bosai Mining Company, China, were engaged in manganese mining in Guyana and presented with unexplained fever. Two of them died. After preliminary examination by the local hospital, some potential infectious pathogens were excluded, including Leptospira, HIV, influenza H1N1, Zika virus, Chikungunya virus, Dengue virus, and Influenza A and B viruses. Histoplasmosis is a fungal disease caused by members of the genus Histoplasma and is mainly prevalent in the American continents. Histoplasma is capable of survival in moist soils and can often be isolated from soils containing decaying feces of bats and birds. Human activities in the surface soil produce aerosols, which in turn are inhaled to cause infection. • New findings In response to the unexplained disease cluster, pathological examination, high through-put sequencing and real-time PCR were implemented. A TGS platform found Histoplasma within 13 hours. NGS was also successfully applied in response to this event. Compared with NGS, the main features of nanopore sequencing are long sequencing ability, simplicity of use, the fastest turn-around time, high portability and real-time analysis of sequencing data. Though NGS had a longer turnaround time (24 hours), it worked well with different sample types (lung tissue, brain tissue and serum from deceased cases and plasma from a severe case) and was more sensitive than nanopore sequencing. Real-time PCR assays did not reveal any infection by viruses related to bat feces transmission. Pathological detection results showed the presence of spore-like structures, indicating fungus infection in this patient. All the results were consistent with the NGS analysis, supporting the fungus infection. • Significance of the study We concluded that H. capsulatum is the causative pathogen for this disease cluster based on epidemiologic, clinical, pathological and nucleic acid supportive evidence.

BackgroundMore than ten novel COVID-19 vaccines have been approved with protections against SARS-CoV-2 infections ranges between 52-95%. It is of great interest to the vaccinees who have received the COVID-19 vaccines, vaccine developers and authorities to identify the non-responders in a timely manner so intervention can take place by either giving additional boosts of the same vaccine or switching to a different vaccine to improve the protection against the SARS-CoV-2 infections. A robust correlation was seen between binding antibody titer and efficacy (p=0.93) in the clinic studies of 7 COVID-19 vaccines, so it is of urgency to develop a simple POCT for vaccinees to self-assess their immune response at home.MethodsUsing CHO cell-expressed full length SARS-CoV2 S1 protein as coating antigen on colloidal gold particles, a SARS-CoV-2 S1 IgG-IgM antibody lateral flow test kit (POCT) was developed. The test was validated with negative human sera collected prior to the COVID-19 outbreaks, and blood samples from human subjects prior, during, and post-immunization of COVID-19 vaccines.ResultsThe specificity of the POCT was 99.0%, as examined against 947 normal human sera and 20 whole blood samples collected pre-immunization. The limit of detection was 50 IU/mL of pseudovirus neutralizing titer (PVNT) using human anti-SARS-2 neutralizing standards from convalescent sera. The sensitivity of POCT for SARS-CoV-2 S1 protein antibody IgG-IgM was compared with SARS-CoV-2 RBD antibody ELISA and determined to be 100% using 23 blood samples from vaccinated human subjects and 10 samples from non-vaccinated ones. Whole blood samples were collected from 119 human subjects (ages between 22-61 years) prior to, during, and post-vaccination of five different COVID-19 vaccines. Among them, 115 people tested positive for SARS-CoV-2 S1 antibodies (showing positive at least once) and 4 people tested negative (tested negative at least twice on different days), demonstrating 96.64% of seroconversion after full-vaccination. 92.3% (36/39) of the human subjects who were younger than 45 achieved seroconversion within 2 weeks while only 57.1% (4/7) of subjects older than 45 tested positive for S1 antibodies, suggesting that younger people develop protection much faster than older ones. Even though the S1 antibody level in 88% of human subjects vaccinated with inactivated virus dropped below 50 IU/mL two months later, one boost could quickly raise the S1 antibody titer above 50 IU/mL of PVNT, indicates that the initial vaccination was successful and immunization memory was developed.ConclusionUsing the lateral flow tests of SARS-CoV2 S1 IgG+IgM, vaccinated human subjects can easily self-assess the efficacy of their vaccination at home. The vaccine developer could quickly identify those non-responders and give them an additional boost to improve the efficacy of their vaccines. Vaccinees who failed in response could switch to different types of COVID-19 vaccines since there are more than 10 COVID-19 vaccines approved using three different platform technologies.HighlightsMore than ten novel COVID-19 vaccines have been approved with protections against SARS-CoV-2 infections ranges between 52-95%. It is of great interest to the vaccinees who have received the COVID-19 vaccines, vaccine developers and authorities to identify the non-responders in a timely manner.A highly specific and very simple lateral flow test kit for measurement of SARS-CoV-2 S1IgG+IgM antibodies post-immunization of COVID-19 vaccine using peripheral blood was developed as a home-test assay with a limit of detection (LOD) at 50 IU/mL of pseudovirus neutralizing titer (PVNT).After full vaccinations with COVID-19 vaccines, 96.6% of the volunteers successfully achieved the seroconversion of SARS-CoV-2 S1 IgG+IgM antibody.92.3% (36/39) of the human subjects who were younger than 45 achieved seroconversion within 2 weeks while only 57.1% (4/7) of subjects older than 45 tested positive for S1 antibodies, suggesting that younger people develop protection much faster than older ones.Even though the S1 antibody level in 88% of human subjects vaccinated with inactivated virus dropped below the detection 2-6 months later, one boost could quickly raise the S1 antibody titer above 50 IU/mL of PVNT, indicating that the initial vaccination was successful and immunization memory was developed.

Most COVID-19 patients can build effective humoral immunity against SARS-CoV-2 after recovery(1, 2). However, it remains unknown how long the protection can maintain and how efficiently it can protect people from the reinfection of the emerging SARS-CoV-2 variants. Here we evaluated the sera from 248 COVID-19 convalescents around one year post-infection in Wuhan, the earliest epicenter of SARS-CoV-2. We demonstrated that the SARS-CoV-2 immunoglobulin G (IgG) maintains at a high level and potently neutralizes the infection of the original strain (WT) and the B.1.1.7 variant in most patients. However, they showed varying degrees of efficacy reduction against the other variants of concern (P.1, B.1.525, and especially B.1.351) in a patient-specific manner. Mutations in RBD including K417N, E484K, and E484Q/L452R (B.1.617) remarkably impair the neutralizing activity of the convalescents’ sera. Encouragingly, we found that a small fraction of patients’ sera showed broad neutralization potency to multiple variants and mutants, suggesting the existence of broadly neutralizing antibodies recognizing the epitopes beyond the mutation sites. Our results suggest that the SARS-CoV-2 vaccination effectiveness relies more on the timely re-administration of the epitope-updated vaccine than the durability of the neutralizing antibodies.

Parents raising children with autism spectrum disorder (ASD) usually carry on their daily life under tremendous stress, but limited empirical research has been devoted to this population. It is known that parents' health status directly impacts therapeutic outcome of ASD children. As an important regulator in cardiovascular, nervous and immune systems, nitric oxide (NO) levels haven't been reported in parents of ASD children yet. In this study, we measured urine nitrite and nitrate from 43 ASD parents (ASD-P), and 43 healthy adults in the same range of age (Control) who didn't have any ASD descendants. Comparison between the ASD-P and Control groups showed that NO2-, NO3-, and NO2-/NO3- were all significantly lower in the ASD-P group. Analysis on the interaction effect of sex and group indicated that urine NO3- of mothers in ASD-P was lower than that in females of the Control group, but no significant difference was observed between males in both groups. It is for the first time that urine nitric oxide metabolites (nitrite, nitrate) levels were precisely reported to differentiate parents of autistic children from other adults without ASD descendants. This phenomenon suggests that parents (especially mothers) of autistic children might have experienced more mental and physical stressors, which led to decreased NO levels during metabolism. Further investigations are necessary to uncover the etiology of low urine NO among parents of autistic children.

Rheumatoid arthritis (RA) is associated with increased localized and generalized bone loss, but the complex genetic mechanism between them is still unknown. By leveraging large-scale genome-wide association studies summary statistics and individual-level datasets (i.e. UK Biobank), a series of genetic approaches were conducted. Linkage disequilibrium score regression reveals a shared genetic correlation between RA and estimated bone mineral density (eBMD) (rg = −0.059, P = 0.005). The PLACO analysis has identified 74 lead (8 novel) pleiotropic loci that could be mapped to 99 genes, the genetic functions of which reveal the possible mechanism underlying RA and osteoporosis. In European, genetic risk score (GRS) and comprehensive Mendelian randomization (MR) were utilized to evaluate the causal association between RA and osteoporosis in European and Asian. The increase in GRS of RA could lead to a decrease of eBMD (beta = −0.008, P = 3.77E-6) and a higher risk of facture [odds ratio (OR) = 1.012, P = 0.044]. MR analysis identified that genetically determined RA was causally associated with eBMD (beta = −0.021, P = 4.14E-05) and fracture risk (OR = 1.036, P = 0.004). Similar results were also observed in Asian that osteoporosis risk could be causally increased by RA (OR = 1.130, P = 1.04E-03) as well as antibodies against citrullinated proteins-positive RA (OR = 1.083, P = 0.015). Overall, our study reveals complex genetic mechanism between RA and osteoporosis and provides strong evidence for crucial role of RA in pathogenesis of osteoporosis.

Epigenetic alterations play an important role in tumor progression of diffuse large B-cell lymphoma (DLBCL). However, the biological relevance of epigenetic gene mutations on tumor microenvironment remains to be determined. The core set of genes relating to histone methylation (KMT2D, KMT2C, EZH2), histone acetylation (CREBBP, EP300), DNA methylation (TET2), and chromatin remodeling (ARID1A) were detected in the training cohort of 316 patients by whole-genome/exome sequencing (WGS/WES) and in the validation cohort of 303 patients with newly diagnosed DLBCL by targeted sequencing. Their correlation with peripheral blood immune cells and clinical outcomes were assessed. Underlying mechanisms on tumor microenvironment were investigated both in vitro and in vivo. Among all 619 DLBCL patients, somatic mutations in KMT2D (19.5%) were most frequently observed, followed by mutations in ARID1A (8.7%), CREBBP (8.4%), KMT2C (8.2%), TET2 (7.8%), EP300 (6.8%), and EZH2 (2.9%). Among them, CREBBP/EP300 mutations were significantly associated with decreased peripheral blood absolute lymphocyte-to-monocyte ratios, as well as inferior progression-free and overall survival. In B-lymphoma cells, the mutation or knockdown of CREBBP or EP300 inhibited H3K27 acetylation, downregulated FBXW7 expression, activated the NOTCH pathway, and downstream CCL2/CSF1 expression, resulting in tumor-associated macrophage polarization to M2 phenotype and tumor cell proliferation. In B-lymphoma murine models, xenografted tumors bearing CREBBP/EP300 mutation presented lower H3K27 acetylation, higher M2 macrophage recruitment, and more rapid tumor growth than those with CREBBP/EP300 wild-type control via FBXW7-NOTCH-CCL2/CSF1 axis. Our work thus contributed to the understanding of aberrant histone acetylation regulation on tumor microenvironment as an alternative mechanism of tumor progression in DLBCL.

Excessive free fatty acid- (FFA-) induced endothelial lipotoxicity is involved in the pathogenesis of atherosclerosis. Endoplasmic reticulum (ER) stress is mechanistically related to endothelial lipotoxicity. Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is the major oxidatively modified low-density lipoprotein (OxLDL) receptor in endothelial cells and is highly abundant in atherosclerotic lesions. Curcumin reduces the LOX-1 expression; however, the mechanism underlying this effect remains unknown. In the current study, we explored whether curcumin ameliorates palmitic acid- (PA-) induced endothelial lipotoxicity and LOX-1 upregulation by reducing ER stress in human umbilical vein endothelial cells (HUVECs). We built endothelial lipotoxicity in vitro and found that LOX-1 was upregulated after PA stimulation, during which ER stress played an important role. Next, we observed that curcumin substantially alleviated PA-induced lipotoxicity by restoring cell viability, increasing angiogenesis, and decreasing lipid deposition. Furthermore, LOX-1 upregulation in HUVECs was blocked by curcumin, possibly via ER stress suppression. Overall, our findings demonstrated that curcumin alleviates endothelial lipotoxicity and LOX-1 upregulation, and ER stress inhibition may play a critical role in this effect.

Nitric oxide (NO) plays an important role in cardiovascular and immune systems. Quantification of blood nitrite and nitrate, two relatively stable metabolites of NO (generally as NOx), has been acknowledged representing NO bioactivity partially. Dysregulation of NOx had been reported in SARS-CoV-2 infected populations, but whether patients recovered from COVID-19 disease present with restored NOx is unknown. In this study, serum NO2− and NO3− were quantified and analyzed among 109 recovered adults in comparison to a control group of 166 uninfected adults. Nitrite or nitrate levels were not significantly different among mild-, common-, severe- and critical-type patients. However, these recovered patients had dramatically lower NO2− and NO2−/NO3− than the uninfected group (p, Graphical abstract Image 1

Aim: The aims of the study were to evaluate the non-inferiority of the safety and immunogenicity of a new trial purified vero cell-cultured rabies vaccine (trial vaccine) in healthy subjects comparing with the control purified vero cell-cultured rabies vaccine (control vaccine) following Essen regimen and to evaluate the non-inferiority of the safety and immunogenicity of the trial vaccine following two intramuscular regimens, between Zagreb and Essen regimen. Methods: Serum samples were collected before vaccination and on d 7, 14, 35/42 post vaccination. Adverse events (AEs) were recorded for 30 d following each vaccination. This study was registered in the Chinese Clinical Trial Registry (ChiCTR-PPR-15007057). Results: There was no significant difference in the incidence of AEs, local and systemic reactions, among Zagreb group, Essen group, and control group. But the incidence of solicited AEs was a significant difference among the three groups (p = 0.0498). The incidence of solicited AEs was higher in Essen group than that in control group and Zagreb group (p = 0.0278, p = 0.0248). In the subjects whose antibodies were seronegative before vaccination, the seroconversion rates of antibodies among three groups were all 100.0% on d 14 and d 35/42. The Essen group was not inferior to the control group, and the Zagreb group was not inferior to the Essen group on d 14. On d 14 and d 35/42, the geometric mean concentration of the three groups was much higher than the immune protection level of 0.5 IU/ml. Conclusions: The trial vaccine had good safety and immunogenicity, and the trial vaccine is not inferior to the control vaccine. Abbreviations: PVRV: purified vero cell-cultured rabies vaccine; AE: adverse event; CI: confidence interval; GMC: geometric mean concentration; IM: intramuscular; NIFDC: National Institutes for Food and Drug Control; PPS: per-protocol set; SS: safety set; REFIT: Rapid Fluorescent Focus Inhibition Test; RVNA: rabies virus neutralizing antibody; WHO: World Health Organization.

Objective To evaluate the performance of an ultrafast single-tube nucleic acid isothermal amplification detection assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA using clinical samples from multiple centres. Methods A reverse transcription recombinase–aided amplification (RT-RAA) assay for SARS-CoV-2 was conducted within 15 minutes at 39°C with portable instruments after addition of extracted RNA. The clinical performance of RT-RAA assay was evaluated using 947 clinical samples from five institutions in four regions of China; approved commercial fluorescence quantitative real-time PCR (qRT-PCR) kits were used for parallel detection. The sensitivity and specificity of RT-RAA were compared and analysed. Results The RT-RAA test results of 926 samples were consistent with those of qRT-PCR (330 were positive, 596 negative); 21 results were inconsistent. The sensitivity and specificity of RT-RAA was 97.63% (330/338, 95% confidence interval (CI) 95.21 to 98.90) and 97.87% (596/609, 95% CI 96.28 to 98.81) respectively. The positive and negative predictive values were 96.21% (330/343, 95% CI 93.45 to 97.88) and 98.68% (596/604, 95% CI 97.30 to 99.38) respectively. The total coincidence rate was 97.78% (926/947, 95% CI 96.80 to 98.70), and the kappa was 0.952 (p Conclusions With comparable sensitivity and specificity to the commercial qRT-PCR kits, RT-RAA assay for SARS-CoV-2 exhibited the distinctive advantages of simplicity and rapidity in terms of operation and turnaround time.

The chitooligosaccharide (COS) and chlorella polysaccharide (CPS) have been used as feed supplements in the poultry industry for improving growth performance and immunity. However, the benefits of these prebiotics on the gut health of chickens when used in early nutrition are unknown. This study evaluated the effects of in ovo feeding of COS and CPS on the cecal microbiome, metabolic pathways, and fermentation metabolites of chickens. A total of 240 fertile eggs were divided into 6 groups (n = 4; 10 eggs/replicate): 1) no-injection control, 2) normal saline control, 3) COS 5 mg, 4) COS 20 mg, 5) CPS 5 mg, and 6) CPS 20 mg injection. On day 12.5 of egg incubation, test substrate was injected into the amniotic sac of eggs in respective treatments. The hatched chicks were raised for 21 D under standard husbandry practices. On day 3 and 21, cecal digesta were collected to determine microbiota by shotgun metagenomic sequencing and short-chain fatty acids by gas chromatography. The cecal microbial composition was not different (P > 0.05) among the treatment groups on day 3 but was different (P

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by the SFTS virus (SFTSV). Hubei Province is a major epidemic area for SFTS in China. In this study, quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and serological testing (IgM) were used simultaneously for laboratory detection of SFTS; however, testing results showed poor consistency between these two methods. Further analysis revealed that time post-onset was the main factor leading to inconsistent results. Thus, qRT-PCR is unable to detect all SFTS cases, and serological testing is essential. Here, 15 strains of SFTSV were successfully isolated from serum samples of acute SFTSV infection and their complete genomes were sequenced and submitted to GenBank. Phylogenetic analysis showed that the 15 SFTS virus strains clustered into four independent genotypes (A, B, D, and E), demonstrating that at least four genotypes of SFTSV have been co-circulating in Hubei Province. Furthermore, four strains of our isolates (HB2014-31, HB2014-35, HB2014-36, and HB2014-37) clustered in genotype E, which was the predominant genotype in Japan and South Korea. In this study, we identified multiple co-prevalent genotypes and confirmed the existence of genotype E viruses circulating in the Dabie Mountains of Hubei, central China. We concluded that SFTSV strains from Hubei exhibit most of the genetic diversity found in China.

Norovirus (NoV) is a major pathogenic agent of human acute viral gastroenteritis that occurs worldwide. In March 2017, a series of acute NoV-associated gastroenteritis outbreaks occurred in Hubei Province in central China. Here, we sought to better understand the main genotypes and potential evolutionary advantages of circulating NoV strains underlying these outbreaks. During the outbreak, 111 fecal swabs and stool samples were collected from outpatients with acute NoV-associated gastroenteritis in Hubei Province. RNA was extracted from the samples and used as a template for real-time RT-PCR. Sequencing of a portion of the capsid gene and the ORF1/ORF2 overlap was used to assess DNA sequence homology, phylogeny, and recombination using pairwise alignments, MEGA, and Simplot, respectively. Bayesian evolutionary inference analysis was performed using the BEAST software platform to assess the genetic relationships, evolution rate, and evolutionary history of norovirus. GII NoV was determined to be the major pathogen of the acute gastroenteritis outbreaks in Hubei Province, with a 57.7% positive rate. Homology and phylogenic analysis of a portion of the capsid region for GII NoV isolates collected during outbreaks in Hubei showed that the isolates had a very high sequence identity and belonged to GII.2 genotype. Phylogenetic analysis of recombination using the ORF1/ORF2 overlap region revealed a recombinant strain, GII.P16_GII.2, in samples isolated from Hubei Province. The partial polymerase region and capsid gene of the recombinant strain had very high identity (98.7-98.8%) with the NoV strains isolated in Germany in 2016. The evolutionary rate of VP1 gene of GII.2 was distinctly higher than that of the partial polymerase region of GII.16. A phylogenetic tree generated using MCMC showed that the recombinant NoV GII.16_GII.2 was significantly divergent from other GII.16_GII.2 strains observed in China and Japan. Continued circulation of this GII.16_GII.2 recombinant could overtake the predominant GII.4 NoV strain with geographic expansion. Further analysis of the evolutionary dynamics of norovirus is necessary to develop more effective prevention and control strategies.

Background: This network meta-analysis aimed at comparing anti-programmed death 1 (anti-PD-1) with anti-programmed death ligand 1(anti-PD-L1) immunotherapy in patients with metastatic, previously treated non-small cell lung cancer (NSCLC) who failed first-line treatment. Methods: We searched electronic databases to identify all eligible clinical trials. End-points included overall survival (OS), progression-free survival (PFS) and objective response. Hazard ratios (HRs) or odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were extracted. Network meta-analysis was performed using the frequentist approach for multiple treatment comparisons. Results: In total, 3024 patients were randomly assigned: 1117 received anti-PD-1 therapy (nivolumab + pembrolizumab), 569 received anti-PD-L1 (atezolizumab) and 1338 received docetaxel. Anti-PD-1 (HR, 0.56; 95% CI, 0.48-0.66) and anti-PD-L1 (HR, 0.64; 95% CI, 0.51-0.79) achieved better OS than docetaxel, and anti-PD-1 was superior to docetaxel in terms of PFS (HR, 0.75; 95% CI, 0.62-0.89). Moreover, anti-PD-1 achieved the highest effect on OS and PFS, with a P-score of 91.2% and 95.5%, respectively. With regard to tumor response, anti-PD-1 group had a higher rate of responders than that in anti-PD-L1 (HR, 0.35; 95% CI, 0.19-0.65) and docetaxel (HR, 0.36; 95% CI, 0.25-0.52) groups. Undoubtedly, anti-PD-1 and anti-PD-L1 obtained less toxicity profile than docetaxel, and no significant difference was observed between anti-PD-1 and anti-PD-L1 groups. Conclusions: Anti-PD-1 may be a better choice for patients with metastatic and previously treated NSCLC who failed first-line treatment in terms of the treatment ranking.

The Central Plains Economic Region (CPER) is located in central eastern China and has experienced tremendous economic growth in the last decade. Like many areas in China, the rapid economic development of the CPER has led to serious air pollution problems, including extremely high concentrations of nitrogen dioxide (NO2) and particulate matter with an aerodynamic diameter less than 2.5 µm (PM2.5). However, the current air pollution monitoring system lacks good spatial and temporal coverage. Therefore, we used high-resolution satellite remote sensing techniques to analyze the variation in NO2 and PM2.5 in the CPER from 2005 through 2015. The Ozone Monitoring Instrument (OMI) and the Moderate Resolution Imaging Spectroradiometer (MODIS) were used to retrieve the tropospheric NO2 columns and ground-level PM2.5 concentrations, respectively. High NO2 and PM2.5 concentrations were mainly located in the central and northern areas of the CPER. The highest 11-year average concentrations were found in the city of Jiaozuo for NO2 (19.54 × 1015 molecules cm–2) and in the city of Hebi for PM2.5 (107.8 µg m–3). The western and southern mountainous areas had lower NO2 and PM2.5 concentrations. The average seasonal NO2 and PM2.5 concentrations were both highest in winter and lowest in summer. The average monthly concentrations of NO2 and PM2.5 were as high as 24.60 × 1015 molecules cm–2 and 152.2 µg m–3, respectively, in January 2013 and as low as 43.86 × 1015 molecules cm–2 and 40.2 µg m–3, respectively, in July 2006. During the 11-year study period (2005–2015), the CPER concentrations of both NO2 and PM2.5 decreased from 2011 to 2015 by 31.5% and 36.8%, respectively. This study successfully applies satellite remote sensing data to quantitatively analyze the spatial-temporal distributions of tropospheric NO2 and ground-level PM2.5. This approach can support air pollution monitoring in the CPER, and the estimated concentrations can provide references for environmental policymaking.

Litchis are tasty fruit with economic importance. However, the extreme susceptibility of harvested litchis to litchi downy blight caused by Peronophythora litchii leads to compromised quality. This study aimed to study the effects of melatonin on postharvest resistance to P. litchii in 'Feizixiao' litchis. Results showed that melatonin restricted lesion expansion in litchis after P. litchi inoculation. Melatonin enhanced the activities of phenylalanine ammonia-lyase, cinnamate-4-hydroxylase and 4-hydroxycinnamate CoA ligase while promoting the accumulations of phenolics and flavonoids. Nicotinamide adenine dinucleotide phosphate content and glucose-6-phosphate dehydrogenase and 6-phosphogluconic acid dehydrogenase activities were higher in treated fruit than control fruit. Higher energy status along with elevated H+-ATPase, Ca2+-ATPase, succinate dehydrogenase and cytochrome C oxidase activities were observed in treated fruit. Ultrastructural observation showed reduced damage in mitochondria in treated fruit. The results suggest that melatonin induced resistance in litchis by modulating the phenylpropanoid and pentose phosphate pathways as well as energy metabolism. .

In a short nanobearing system made from carbon nanotubes, the rotor with high rotational frequency may escape from the stator, which may cause a stability problem to the system of a nanodevice with such a nanobearing. In the present work, nanobearings with tri-walled nanotubes are investigated to reveal the conditions for the moving away of the free inner tube from the high-speed rotating middle tube. Experimental results show that the escape happens when the radii difference between the two rotors is larger than 0.34 nm and the rotational frequency of the middle tube is higher than a critical value. And before the escape occurs, the rotational frequency of the inner tube is lower than this critical value. Due to the radii difference being larger than 0.34 nm, the two rotors are non-coaxial, and the centrifugal force of the inner tube results in strong radial and axial interactions between the edges of the two rotors. When the relative sliding speed is relatively high, an edge of the inner rotor will pass through the potential barrier at the adjacent edge of the middle rotor, and further escape from the middle rotor occurs. The selection of a longer middle rotor with smaller radius can increase the critical rotational frequency of the middle rotor.

Background/Aims. Nucleotide diversity may affect the immune regulation of tuberculosis (TB) patients, leading to the individual susceptibility to TB. In recent years, there are a lot of researches on the association of host genetic factors and TB susceptibility which has attracted increasing attention, and the in-depth study of its mechanism is gradually clear.Materials. We made a minireview on the association of many candidate genes with TB based on recent research studies systematically, such as the human leukocyte antigen (HLA) gene, the solute carrier family 11 member 1 (SLC11A1) gene system, the vitamin D receptor (VDR) gene, the mannan-binding lectin (MBL) gene, the nitric oxide synthase 2A (NOS2A) gene, the speckled 110 (SP110) gene, and the P2X7 receptor (P2X7) gene. The discovery of these candidate genes could reveal the pathogenesis of TB comprehensively and is crucial to provide scientific evidence for formulating the related measures of prevention and cure.Discussion. The host genes play important roles in the development of TB, and the host genes may become new targets for the prevention and treatment of TB. Effective regulation of host genes may help prevent or even treat TB.Conclusion. This minireview focuses on the association of host genes with the development of TB, which may supply some clues for future therapies and novel drug targets for TB.

Background and Objective: Both induction chemotherapy (IC) followed by concurrent chemoradiotherapy (CCRT; IC+CCRT) and CCRT plus adjuvant chemotherapy (AC; CCRT+AC) are standard treatments for advanced nasopharyngeal carcinoma (NPC). However, no prospective randomized trials comparing these two approaches have been published yet. We conducted this network meta-analysis to address this clinical question. Method: We recruited randomized clinical trials involving patients with advanced NPC randomly allocated to IC+CCRT, CCRT+AC, CCRT, or radiotherapy (RT) alone. Pairwise meta-analysis was first conducted, then network meta-analysis was performed using the frequentist approach. Effect size was expressed as hazard ratio (HR) and 95% confidence interval (CI). Results: Overall, 12 trials involving 3,248 patients were recruited for this study, with 555 receiving IC+CCRT, 840 receiving CCRT+AC, 1,039 receiving CCRT, and 814 receiving radiotherapy (RT) alone. IC+CCRT achieved significantly better overall survival ([HR], 0.69; 95% [CI], 0.51-0.92), distant metastasis-free survival (HR, 0.58; 95% CI, 0.44-0.78), and locoregional recurrence-free survival (HR, 0.67; 95% CI, 0.47-0.98) than CCRT. However, survival outcomes did not significantly differ between IC+CCRT and CCRT+AC, or between CCRT+AC and CCRT arms for all the endpoints. As expected, RT alone is the poorest treatment. In terms of P-score, IC+CCRT ranked best for overall survival (96.1%), distant metastasis-free survival (99.0%) and locoregional recurrence-free survival (87.1%). Conclusions: IC+CCRT may be a better and more promising treatment strategy for advanced NPC; however, head-to-head randomized trials comparing IC-CCRT with CCRT-AC are warranted.

Ten marine species, including different crabs, bivalve molluscs, and fish intestines were selected to screen the natural antimicrobial protein or peptide as they are enriched with various microorganisms. The crude extract from Varuna litterata, a marine crab which is used as a raw material in the preparation of pickled crabs in Chaoshan area of China, was proved to have a potent bacteriostatic effect against gram-negative bacterium (Escherichia coli) and gram-positive bacterium(Staphylococcus aureus) compared with other marine species. The crude proteins of Varunalitterata were salted-out for preliminary purification and further purified by gel filtration (Sephadex G-150) or anion exchange (DEAE-cellulose 52) chromatographic column. An increase in the antimicrobial activity was noted with the increase in the purity level of the protein. A relatively pure protein was eventually obtained, which was determined to be belonging to the hemocyanin family based on the mass spectrometric data analysis. The purified proteins solution (1 mg/ml) from Varuna litterata exhibited similar antimicrobial activity to that of gentamycin sulfate (0.2 mg/ml), which were relatively stable in a certain pH or temperature range. A structure-activity relationship of the purified hemocyanin was determined based on the interaction of hemocyanin and different chromatographic medium, which revealed that the integrated hexamers played a remarkable role in its bacteriostatic activity. Moreover, the phenoloxidase activity of hemocyanin from Varuna litterata was found as the underlying cause of its antimicrobial potential.

In this paper, the finite element method (FEM) is employed for analyzing the strength of a bonded sandwich beam with corrugated core. The adhesive layer (AL) is discretized and modeled with beam elements. A strength criterion and stiffness degeneration law of an AL is proposed. Effects of the configuration of the corrugated core on structural strength are investigated using a representative beam model containing three panels bonded with two corrugated layers. Two major geometrical parameters are considered: the angle between the oblique side and the horizontal bonding side of the corrugated layer and the overlap length of the two corrugated layers on both sides of the central panel. Numerical results obtained from 3-point bending tests show that the beam structure possesses maximum strength when the angle equals 90° and the overlap length of two corrugated layers is equal to the length of the horizontal bonding side of the corrugated layer. The crack expansion in ALs is also analyzed. It is found that the possibility crack expansion in the ALs near the upper and lower boundary is obviously greater than that in ALs near the neutral layer of beam structure. Furthermore, the flexibility of a bonded structure can be improved by enhancing the strength of the AL boundary. Keywords: Bonded composite, Sandwich beam, Damage analysis, Finite element method

The present study explored the inhibitory effect of hyperthermic CO2 pneumoperitoneum on the proliferation and migration of colon cancer cells, and its mechanism. Colon cancer cell line SW-480 was sealed into a urine collection bag to simulate pneumoperitoneum with 100% CO2 under a pressure of 14 mmHg. The growth and morphology of cells were observed under a microscope, the inhibition on cell proliferation was measured using WST-8 test, cell apoptosis and the cell cycle were monitored using fluorescence-activated cell sorting analysis, the migration of cells was tested using the scratch assay, and the expression of HSP-70, caspase-3, hypoxia-inducible factor-1α (HIF-1α) and matrix metalloproteinase-9 (MMP-9) proteins and genes was investigated using western blotting and reverse transcription polymerase chain reaction. Compared with the control group, there was no significant difference in the CO2 group (P>0.05), while the apoptosis and necrosis rates in the hyperthermo-CO2 group was significantly increased (P

A modified solid isotropic material with penalization (SIMP) method is proposed for solving layout optimization problems of multiple bi-modulus materials in a continuum. In the present algorithm, each bi-modulus material is replaced by two distinct isotropic materials to avoid structural reanalysis for each update of the design domains. To reduce the error in local stiffness due to the material replacement, the modification factor of each finite element is calculated according to the local stress state and the moduli used in the previous structural analysis. Three numerical examples are considered to demonstrate the validity and applicability of the present approach. Numerical results show that the final layout of materials is determined by factors that include the moduli difference of each bi-modulus material and the difference among material moduli.

Recently, NASA's Multiangle Imaging SpectroRadiometer (MISR) team released the Version 23 (V23) 4.4-km Aerosol Optical Depth (AOD) product, which has better spatial resolution than V22 at 17.6 km. However, its quality has not been validated in China. Here, V23 products for different spatiotemporal domains are obtained for validation against Aerosol Robotic NETwork (AERONET) AOD measurements for 29 sites from 2008 to 2017. Based on the national daily mean, V23 AOD yields a correlation coefficient (R) of 0.902 with AERONET; 59.45% of retrievals fall within the expected error (=EE; ± 0.05 or ± 0.2 × AOD ). A mean error (ME) of −0.0605 with 24.11% of retrievals falling below the EE indicates that MISR data are still underestimated at high AODs. The sample numbers and accuracies of spatially averaged 17.6-km and 50-km data are greatly improved relative to V22. The seasonal mean of V23 retrievals = EE in fall and winter are highest, followed by those in summer and spring; the validation results at 17.6 km are generally better than those at 50 km. By region, V23 retrievals = EE in the Beijing–Tianjin–Hebei (BTH), Yangtze River Delta (YRD) and Pearl River Delta (PRD) regions are 68.87%, 61.43%, and 73.13% respectively, while that of Taiwan is below 60% (55.75%). No V22 records exist in PRD, and V23 products over other regions in all seasons perform well; V22 retrievals in summer are also recommended. Compared with Terra/MODIS 3-km AOD in 2016, the V23 product has a slightly higher R value (0.925) with AERONET than MODIS (0.909). The MISR AOD bias is lower, and MODIS AOD is overestimated relative to the ground truth; both present consistent seasonality characteristics (spring > winter > summer > autumn), with the maximum in March and minimum in August. To investigate the spatiotemporal characteristics over long-term AOD, MISR V23 4.4-km AOD can be used in combination with other observation data.

The mechanical properties of bonded graphene ribbon were evaluated via uniaxial tensile tests by molecular dynamics simulations. For an ideal/pristine few-layered graphene ribbon, the interlayer superlubrication leads to easily relative sliding between neighboring layers. When the layers in the ribbon are sewn by collision with high speed fullerenes from both sides, a new two-dimensional material is fabricated. A part of bonds in the original graphene layers are broken, and new bonds are generated to connect the neighboring layers at the impacted areas. The in-plane mechanical properties, e.g., Young’s modulus, maximal engineering strain (which demonstrates deformability), deformation energy (which illustrates structural stiffness) and the maximal stress (which describes strength), of the newly fabricated defective ribbon are different from the original ideal ribbon. By comparison with the ideal ribbon, the changes of the mechanical properties were demonstrated. Meanwhile, temperature effect on the changes of properties was also discussed for potential application of the new two-dimensional material. In brief, the maximal strain slightly depends on temperature and loading speed. The defective ribbon breaks in tension failure mode when stretched along x/zigzag direction, but in shear failure mode when stretched along y/armchair direction. The Young’s modulus reduces 10%–12%, but, the maximal strain reduces more than 50% when compared with the ideal ribbon.

The entire stx1 region from Escherichia coli O157:H7, containing two open reading frames (stx1a and stx1b), was cloned into pET-32a with a single promoter. This region was transformed into E. coli TransB (DE3), which is a trxB and gor mutation strain. After expression in the E. coli periplasm in a completely soluble form, the rStx1 was purified and verified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), ELISA, and Western blot analysis. Our rStx1 have Vero cell median cytotoxic dose (CD50 ) and median lethal dose (LD50 ) values of approximately 30 ng and 1.5 µg, respectively. The final yield of the purified rStx1 ranged from 2 to 3 mg/L by one-step nickel affinity gel column chromatography. This method is an easy approach to the large-scale preparation of Stx1 at a reasonable cost.

Apoptosis and the dysfunction of the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/cAMP-responsive element binding protein (CREB) signaling pathway have a key role in memory impairment in vascular dementia (VaD), a challenging clinical problem. Yifei Xuanfei Jiangzhuo formula (YXJF), a Chinese herbal decoction, has been used to treat VaD in clinical practice and has produced positive outcomes; however, convincing evidence is currently lacking. The present study aimed to investigate the effects of YXJF on memory impairment in rats with cerebral ischemia/reperfusion and to explore the underlying mechanism. YXJF ameliorated memory impairment in rats with cerebral ischemia/reperfusion, inhibited hippocampal apoptosis in a dose-dependent manner and attenuated increases in the protein expression of B-cell lymphoma 2 (Bcl-2)-associated X protein as well as c-Jun and a reduction in Bcl-2 protein expression in the hippocampal tissue of the rats. Furthermore, administration of YXJF significantly increased the protein expression of PKA C-α and CREB, and promoted CREB phosphorylation. The results indicated that YXJF improves memory impairment through inhibiting apoptosis and enhancing PKA/CREB signal transduction in rats with cerebral ischemia/reperfusion.

Vascular dementia (VD) has been one of the most serious public health problems worldwide. It is well known that cerebral hypoperfusion is the key pathophysiological basis of VD, but it remains unclear how global genes in hippocampus respond to cerebral ischemia-reperfusion. In this study, we aimed to reveal the global gene expression profile in the hippocampus of VD using a rat model. VD was induced by repeated occlusion of common carotid arteries followed by reperfusion. The rats with VD were characterized by deficit of memory and cognitive function and by the histopathological changes in the hippocampus, such as a reduction in the number and the size of neurons accompanied by an increase in intercellular space. Microarray analysis of global genes displayed up-regulation of 7 probesets with genes with fold change more than 1.5 (P < 0.05) and down-regulation of 13 probesets with genes with fold change less than 0.667 (P < 0.05) in the hippocampus. Gene Ontology (GO) and pathway analysis showed that the up-regulated genes are mainly involved in oxygen binding and transport, autoimmune response and inflammation, and that the down-regulated genes are related to glucose metabolism, autoimmune response and inflammation, and other biological process, related to memory and cognitive function. Thus, the abnormally expressed genes are closely related to oxygen transport, glucose metabolism, and autoimmune response. The current findings display global gene expression profile of the hippocampus in a rat model of VD, providing new insights into the molecular pathogenesis of VD.

A hydraulic steel radial gate (SRG) with two oblique arms is designed by using topology optimization and size optimization. Topology and size optimization are carried out by using CAD software, e.g., Hyperworks. In the current design, the SRG is initially considered to have three main components, i.e., the arms, the supporting frame of arms and a panel for water retaining. To give a better design of these components, e.g., arms and its supporting frame, topology optimization is adopted. By topology optimization method, the shape of arm and the supporting frame are obtained. As construction of the new SRG is reconstructed by the components obtained, the stiffness, strength and stability of the new SRG is checked and some sizes of components in SRG are readjusted by using size optimization. The final design of the SRG is around 24% lighter than the traditional design whilst the safety of the new design is much better.

Topology optimization of a continuum with bimodulus material under multiple load cases (MLC) is investigated by using material replacement method. Using traditional methods to solve such a problem will encounter two difficulties for the sake of the stress-dependent behavior of bimodulus material. One is the nonlinear behavior of bimodulus material. The other is the definition of local material property under MLC. The present method can overcome the difficulties easily. It contains three major aspects. Firstly, the bimodulus material is replaced with two isotropic materials in optimization. Secondly, the local stiffness is modified according to the stress states because of material replacement. Meanwhile, which one of the isotropic materials to be adopted for each element in the next structural analysis in optimization is determined by the replacement criterion under MLC, i.e., comparing the local CSED (strain energy density (SED) caused by compression stresses) and the TSED (SED caused by tension stresses), the isotropic material which modulus equal to the compression modulus of bimodulus material is used as the material properties of the element if the CSED is greater than the TSED, or vice versa. Finally, the relative densities of elements as the design variables are updated using a gradient-based method. As the reanalysis with respect to material properties for obtaining the accurate deformation is merged into the global iterations of optimization, the efficiency of optimization is highly improved. Numerical examples are given to express the validity and high efficiency of the present method. Results also show that the difference between tension modulus and compression modulus influences the optimal topology of a structure with bimodulus material under MLC, obviously.

Shiga toxin 2 (Stx2) is a major virulence factor in infections with Stx-producing Escherichia coli (STEC), which can cause serious clinical complications in humans, such as hemolytic uremic syndrome (HUS). Recently, we screened and identified two peptide-based Stx2 neutralizers, TF-1 and WA-8, which specifically and directly bind to Stx2. Computer simulations suggested that the majority of TF-1 or WA-8 binds tightly at the receptor-binding site 3 of Stx2. The two peptides also effectively inhibited the cytotoxic activity of Stx2 by blocking the binding of Stx2 to target cells. TF-1 exhibits remarkable therapeutic potency in both mice and rat toxicity models. In mice toxicity models, TF-1 provided full protection when mice were injected with 5 LD50 of Stx2. In rat toxicity models, TF-1 reduced fatal tissue damage and completely protected rats from the lethal challenges of Stx2. In these rats, TF-1 significantly decreased the concentration of Stx2 in blood and diminished tissue distribution levels of Stx2. Furthermore, TF-1 effectively protected rats from the pathological effects caused by Stx2, especially in the kidney, thymus, adrenal gland, and lung. Taken together, these results indicate that TF-1 is a promising therapeutic agent against the pathogenicity of Stx2.

Localized surface plasmons mediated photon energy conversion in ZnO/Ag/ZnO nanostructures has been investigated. Ag nano islands immersed in ZnO cause a great enhancement of visible light emission where silicon solar cells have maximum response, compared to that of ZnO single layer or Ag/ZnO bilayer structures. It is found that the visible light emission enhancement ratio increases with the thickness of the ZnO capping layer and an enhancement ratio of tenfold for 100 nm ZnO is realized. Furthermore, the intensity and peak wavelength of visible light emission are also influenced by the sizes of Ag islands. The observation of photoluminescence from ZnO/Ag/ZnO nanostructures is interpreted with theoretical calculation of localized surface plasmon resonance. The observed large enhancement of visible light emission may have potential applications in high efficiency solar cells by conversion of ultraviolet to visible light.

Infection with Escherichia coli O157:H7 may develop into hemorrhagic colitis, or hemolytic uremic syndrome (HUS), which usually causes kidney failure or even death. The adhesion and toxins are the important virulent factors. In this study, a novel vaccine candidate rSOBGs was constructed based on the bacterial ghost (BG). rSOBGs maintained the integrity of cellular morphology and displayed the linear Stx2Am-Stx1B antigen on the surface of outer membrane. rSOBGs induced Stxs-specific IgA/IgG antibodies and stronger intimin-specific IgA/IgG antibodies effectively in sera in this study. In vivo, the rSOBGs provided the higher protection rate (52%) than native bacterial ghost-OBGs (12%) when challenged intragastricly with high dose (500 LD50) viable E. coli O157:H7. Meanwhile, the rSOBGs provided higher protection rate (73.33%) than OBGs when challenged with 2 LD50 even to 5 LD50 lysed E. coli O157:H7. In vitro, the rSOBGs-immunized sera possessed neutralizing activity to lysed pathogenic bacteria. Furthermore, the results of histopathology also displayed that the administration of rSOBGs have the ability to reduce or inhibit the adhesion lesions and toxins damages of organs. The novel vaccine candidate rSOBGs induced both anti-toxin and anti-adhesion immune protection, suggesting the possibility to prevent the infectious diseases caused by Escherichia coli O157:H7.

A new design scheme of an emersed hydropower arch gate is presented based on topology optimization method. Three main components of the gate, i.e., two arms, a water-retaining face plate and its supporting frame, are considered in the present design method. Both of the layouts of the arms and the supporting frame are obtained by using topology optimization method instead of traditional experiments. In design process, firstly, the location, topology and shape of the arms of gate are obtained. Secondly, the layout of ribs in the support frame is found. Finally, the integrated structure is formed by using the components obtained above and the new gate satisfies such constraints as strength, stiffness and stability. The new gate is about 30% lighter than the one obtained by using traditional method, which means much material is saved and the new gate can be easier for operating.

The genomic DNA of Clostridium botulinum F str. 230613 includes a chromosome (3 993 083 bp, 3502 coding sequences (CDs)) and a plasmid (17 531 bp, 25 CDs). The arrangement of the botulinum neurotoxin serotype F (BoNT/F) gene cluster, a 15-kb (or longer) fragment including the bont gene and other relevant genes, and its different insertion sites in C. botulinum A2 and C. botulinum F were formulated. Mobile elements and virulence factors were analysed. We also found a cell adhesion and pectin lyase domain–containing protein, which may function in attaching to the host and as a pectin lyase. The nine BoNT gene clusters of group I C. botulinum strains were located at three sites in the chromosome of C. botulinum F str. 230613. This study showed the inserting inclination of BoNT/A1 tend to have gene clusters inserted at site 3, BoNT/F at site 2, and BoNT/A2 at site 1. Additionally, we found the recombination event between the BoNT gene clusters of sites 2 and 3, a mechanism that contributed to the diversity of the BoNT gene cluster arrangement.

For a continuum structure filled with many solid phases with different stiffness, the layout of the materials should be optimized to perform an excellent structural mechanical behaviour. The differences between the materials’ moduli affect the final layout of materials in structure. To investigate the effects, a numerical approach is adopted to find the optimal topology of a continuum with multiple materials. In the method, the layout of the material is determined by the local strain energy density (SED). Briefly, in design domain, a material point with higher SED should have higher modulus. To show the effects obviously, a continuum with three phases is used for experiment. In the structure, the modulus of the stiffest material and the volumes of materials are fixed. The other materials’ moduli change alternately. Numerical results demonstrate the layout of materials in structure depends on the differences between the moduli greatly, and the topology of the stiffest material is clear if its modulus is far more than the others.