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Our understanding of the protective immunity, particularly the long-term dynamics of neutralizing antibody (NAbs) response to SARS-CoV-2, is currently limited. We enrolled a cohort of 545 COVID-19 patients from Hubei, China, who were followed up up to 7 months, and determined the dynamics of NAbs to SARS-CoV-2 by using a surrogate virus neutralization test (sVNT). In our validation study, sVNT IC50 titers and the neutralization rate measured at a single dilution (1:20) were well correlated with FRNT titers (r = 0.85 and 0.84, respectively). The median time to seroconversion of NAbs was 5.5 days post onset of symptoms. The rate of positive sVNT was 52% in the first week, reached 100% in the third week, and remained above 97% till 6 months post onset. Quantitatively, NAbs peaked in the fourth week and only a quarter of patients had an estimated peak titer of >1000. NAbs declined with a half-time of 61 days (95% CI: 49–80 days) within the first two months, and the decay deaccelerated to a half-time of 104 days (95% CI: 86–130 days) afterward. The peak levels of NAbs were positively associated with severity of COVID-19 and age, while negatively associated with serum albumin levels. The observation that the low-moderate peak neutralizing activity and fast decay of NAbs in most naturally infected individuals called for caution in evaluating the feasibility of antibody-based therapy and vaccine durability. NAbs response positively correlated with disease severity, warning for the possibility of repeat infection in patients with mild COVID-19.

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) represents a major public health threat worldwide. Insight into protective and pathogenic aspects of SARS-CoV-2 immune responses is critical to work out effective therapeutics and develop vaccines for controlling the disease. Here, we review the present literature describing the innate and adaptive immune responses including innate immune cells, cytokine responses, antibody responses and T cell responses against SARS-CoV-2 in human infection, as well as in AEC2-humanized mouse infection. We also summarize the now known and unknown about the role of the SARS-CoV-2 immune responses. By better understanding the mechanisms that drive the immune responses, we can tailor treatment strategies at specific disease stages and improve our response to this worldwide public health threat., Graphical Abstract Image, graphical abstract

Understanding the immune response to Middle East respiratory syndrome coronavirus (MERS-CoV) is crucial for disease prevention and vaccine development. We studied the antibody responses in 48 human MERS-CoV infection survivors who had variable disease severity in Saudi Arabia. MERS-CoV-specific neutralizing antibodies were detected for 6 years postinfection.

Two outbreaks of severe respiratory infection caused by severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV) caused global pandemics and highlighted the importance of preparedness for respiratory CoVs Recently, a third highly pathogenic CoV, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first identified in Wuhan, Hubei, China and posed a public health crisis worldwide Here, we focus on the recent advances of the novel CoV, and discuss its genomic similarity with other CoVs, transmission, animal model and clinical treatment of coronavirus disease 2019 (COVID-19) induced by SARS-CoV-2, which help epidemic prevention and control, and guide treatment strategies © Journal of Thoracic Disease All rights reserved

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent for coronavirus 2019 (COVID-19) pneumonia. Little is known about the kinetics, tissue distribution, cross-reactivity, and neutralization antibody response in patients with COVID-19. Two groups of patients with RT-PCR–confirmed COVID-19 were enrolled in this study: 12 severely ill patients in intensive care units who needed mechanical ventilation and 11 mildly ill patients in isolation wards. Serial clinical samples were collected for laboratory detection. Results showed that most of the severely ill patients had viral shedding in a variety of tissues for 20–40 days after onset of disease (8/12, 66.7%), while the majority of mildly ill patients had viral shedding restricted to the respiratory tract and had no detectable virus RNA 10 days after onset (9/11, 81.8%). Mildly ill patients showed significantly lower IgM response compared with that of the severe group. IgG responses were detected in most patients in both the severe and mild groups at 9 days after onset, and remained at a high level throughout the study. Antibodies cross-reactive to SARS-CoV and SARS-CoV-2 were detected in patients with COVID-19 but not in patients with MERS. High levels of neutralizing antibodies were induced after about 10 days after onset in both severely and mildly ill patients which were higher in the severe group. SARS-CoV-2 pseudotype neutralization test and focus reduction neutralization test with authentic virus showed consistent results. Sera from patients with COVID-19 inhibited SARS-CoV-2 entry. Sera from convalescent patients with SARS or Middle East respiratory syndrome (MERS) did not. Anti–SARS-CoV-2 S and N IgG levels exhibited a moderate correlation with neutralization titers in patients’ plasma. This study improves our understanding of immune response in humans after SARS-CoV-2 infection.

Human coronavirus NL63 (HCoV-NL63) is primarily associated with common cold in children, elderly and immunocompromised individuals. Outbreaks caused by HCoV-NL63 are rare. Here we report a cluster of HCoV-NL63 cases with severe lower respiratory tract infection that arose in Guangzhou, China, in 2018. Twenty-three hospitalized children were confirmed to be HCoV-NL63 positive, and most of whom were hospitalized with severe pneumonia or acute bronchitis. Whole genomes of HCoV-NL63 were obtained using next-generation sequencing. Phylogenetic and single amino acid polymorphism analyses showed that this outbreak was associated with two subgenotypes (C3 and B) of HCoV-NL63. Half of patients were identified to be related to a new subgenotype C3. One unique amino acid mutation at I507 L in spike protein receptor binding domain (RBD) was detected, which segregated this subgenotype C3 from other known subgenotypes. Pseudotyped virus bearing the I507 L mutation in RBD showed enhanced entry into host cells as compared to the prototype virus. This study proved that HCoV-NL63 was undergoing continuous mutation and has the potential to cause severe lower respiratory disease in humans.

Fully reconfigurable optical filters are indispensable building blocks to realize reconfigurable photonic networks/systems. This paper proposes a reconfigurable and dual-polarization optical filter based on a subwavelength grating waveguide operating in the Bragg reflection mechanism and combined with a low-loss phase change material G e 2 S b 2 S e 4 T e 1 . Numerical simulations indicate that, for TE(TM) polarization, the presented Bragg grating filter offers up to 20 nm (17 nm) redshift with amplitude modulation of 6 dB (0.15 dB) at 1550 nm. Using the effective medium theory, we obtained the six-level crystallization performance of the optical filter. The proposed optical filter has potential applications in wavelength-division-multiplexing systems, optical signal processing, and optical communications.

Background: Human adenovirus type 21 (HAdV-21) is an important member of HAdV species B, but our understanding of this type is limited. Methods: We screened HAdV and 17 other common respiratory pathogens for 1,704 pediatric patients (≤14 years old) hospitalized with acute respiratory illness in Guangzhou, China in 2019. HAdV-21 infections were further confirmed by molecular typing from HAdV-positive patients, and their clinical manifestations, genomes, infectivity and pathogenicity in vitro were analyzed.Results: 151 of 1,704 cases (8.9%) were positive for HAdV, making it the third most frequently detected pathogen. Two sporadic HAdV-21 infections were identified in June and September. Both HAdV-21-positive patients presented with severe lower respiratory illness and had similar initial symptoms at onset of illness. The genome structure of HAdV-21 was found to be similar to that of other members of HAdV species B. The phylogenetic analysis showed that it was closely related to HAdV-B21 strain BB/201903 (MN686206) isolated in Bengbu, China in 2019, suggesting the possibility of the same source, and attention need to be paid to its prevention and control. In vitro, the infectivity and pathogenicity of HAdV-21 were lower than the main epidemic types 7 and 3. Plaques formed by HAdV-21, -7, and -3 were significantly different in shape and size (p < 0.05), with plaques formed by HAdV-21 being the smallest and with poorly defined edges. There was no significant difference between the plaques of the HAdV-21 isolates (p > 0.05). Conclusions: This study provides an important reference for the in-depth understanding of the epidemiology and pathogenicity of HAdV-21, and suggests the necessity of HAdV-21 research, prevention and control.

The current COVID-19 pandemic, caused by SARS-CoV-2, poses a serious public health threat. Effective therapeutic and prophylactic treatments are urgently needed. Angiotensin-converting enzyme 2 (ACE2) is a functional receptor for SARS-CoV-2, which binds to the receptor binding domain (RBD) of SARS-CoV-2 spike protein. Here, we developed recombinant human ACE2-Fc fusion protein (hACE2-Fc) and a hACE2-Fc mutant with reduced catalytic activity. hACE2-Fc and the hACE2-Fc mutant both efficiently blocked entry of SARS-CoV-2, SARS-CoV, and HCoV-NL63 into hACE2-expressing cells and inhibited SARS-CoV-2 S protein-mediated cell–cell fusion. hACE2-Fc also neutralized various SARS-CoV-2 strains with enhanced infectivity including D614G and V367F mutations, as well as the emerging SARS-CoV-2 variants, B.1.1.7 (Alpha), B.1.351 (Beta), B.1.617.1 (Kappa), and B.1.617.2 (Delta), demonstrating its potent and broad-spectrum antiviral effects. In addition, hACE2-Fc proteins protected HBE from SARS-CoV-2 infection. Unlike RBD-targeting neutralizing antibodies, hACE2-Fc treatment did not induce the development of escape mutants. Furthermore, both prophylactic and therapeutic hACE2-Fc treatments effectively protected mice from SARS-CoV-2 infection, as determined by reduced viral replication, weight loss, histological changes, and inflammation in the lungs. The protection provided by hACE2 showed obvious dose-dependent efficacy in vivo. Pharmacokinetic data indicated that hACE2-Fc has a relative long half-life in vivo compared to soluble ACE2, which makes it an excellent candidate for prophylaxis and therapy for COVID-19 as well as for SARS-CoV and HCoV-NL63 infections.

COVID-19 is a huge threat to global health. Due to the lack of definitive etiological therapeutics currently, effective disease monitoring is of high clinical value for better healthcare and management of the large number of COVID-19 patients. In this study, we recruited 37 COVID-19 patients, collected 176 blood samples upon diagnosis and during treatment, and analyzed cell-free DNA (cfDNA) in these samples. We report gross abnormalities in cfDNA of COVID-19 patients, including elevated GC content, altered molecule size and end motif patterns. More importantly, such cfDNA characteristics reflect patient-specific physiological conditions during treatment. Further analysis on tissue origin tracing of cfDNA reveals frequent tissue injuries in COVID-19 patients, which is supported by clinical diagnoses. Hence, we demonstrate the translational merit of cfDNA as valuable analyte for effective disease monitoring, as well as tissue injury assessment in COVID-19 patients.

Disease progression prediction and therapeutic drug target discovery for Coronavirus disease 2019 (COVID-19) are particularly important, as there is still no effective strategy for severe COVID-19 patient treatment. Herein, we performed multi-platform omics analysis of serial plasma and urine samples collected from patients during the course of COVID-19. Integrative analyses of these omics data revealed several potential therapeutic targets, such as ANXA1 and CLEC3B. Molecular changes in plasma indicated dysregulation of macrophage and suppression of T cell functions in severe patients compared to those in non-severe patients. Further, we chose 25 important molecular signatures as potential biomarkers for the prediction of disease severity. The prediction power was validated using corresponding urine samples and plasma samples from new COVID-19 patient cohort, with AUC reached to 0.904 and 0.988, respectively. In conclusion, our omics data proposed not only potential therapeutic targets, but also biomarkers for understanding the pathogenesis of severe COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic of Coronavirus disease 2019 (COVID-19). However, the microbial composition of the respiratory tract and other infected tissues as well as their possible pathogenic contributions to varying degrees of disease severity in COVID-19 patients remain unclear. Between 27 January and 26 February 2020, serial clinical specimens (sputum, nasal and throat swab, anal swab and feces) were collected from a cohort of hospitalized COVID-19 patients, including 8 mildly and 15 severely ill patients in Guangdong province, China. Total RNA was extracted and ultra-deep metatranscriptomic sequencing was performed in combination with laboratory diagnostic assays. We identified distinct signatures of microbial dysbiosis among severely ill COVID-19 patients on broad spectrum antimicrobial therapy. Co-detection of other human respiratory viruses (including human alphaherpesvirus 1, rhinovirus B, and human orthopneumovirus) was demonstrated in 30.8% (4/13) of the severely ill patients, but not in any of the mildly affected patients. Notably, the predominant respiratory microbial taxa of severely ill patients were Burkholderia cepacia complex (BCC), Staphylococcus epidermidis, or Mycoplasma spp. (including M. hominis and M. orale). The presence of the former two bacterial taxa was also confirmed by clinical cultures of respiratory specimens (expectorated sputum or nasal secretions) in 23.1% (3/13) of the severe cases. Finally, a time-dependent, secondary infection of B. cenocepacia with expressions of multiple virulence genes was demonstrated in one severely ill patient, which might accelerate his disease deterioration and death occurring one month after ICU admission. Our findings point to SARS-CoV-2-related microbial dysbiosis and various antibiotic-resistant respiratory microbes/pathogens in hospitalized COVID-19 patients in relation to disease severity. Detection and tracking strategies are needed to prevent the spread of antimicrobial resistance, improve the treatment regimen and clinical outcomes of hospitalized, severely ill COVID-19 patients.

BACKGROUND: Middle East respiratory syndrome (MERS) remains of global public health concern. Dromedary camels are the source of zoonotic infection. Over 70% of MERS coronavirus (MERS-CoV)-infected dromedaries are found in Africa but no zoonotic disease has been reported in Africa. We aimed to understand whether individuals with exposure to dromedaries in Africa had been infected by MERS-CoV. METHODS: Workers slaughtering dromedaries in an abattoir in Kano, Nigeria, were compared with abattoir workers without direct dromedary contact, non-abattoir workers from Kano, and controls from Guangzhou, China. Exposure to dromedaries was ascertained using a questionnaire. Serum and peripheral blood mononuclear cells (PBMCs) were tested for MERS-CoV specific neutralising antibody and T-cell responses. FINDINGS: None of the participants from Nigeria or Guangdong were MERS-CoV seropositive. 18 (30%) of 61 abattoir workers with exposure to dromedaries, but none of 20 abattoir workers without exposure (p=0·0042), ten non-abattoir workers or 24 controls from Guangzhou (p=0·0002) had evidence of MERS-CoV-specific CD4+ or CD8+ T cells in PBMC. T-cell responses to other endemic human coronaviruses (229E, OC43, HKU-1, and NL-63) were observed in all groups with no association with dromedary exposure. Drinking both unpasteurised camel milk and camel urine was significantly and negatively associated with T-cell positivity (odds ratio 0·07, 95% CI 0·01-0·54). INTERPRETATION: Zoonotic infection of dromedary-exposed individuals is taking place in Nigeria and suggests that the extent of MERS-CoV infections in Africa is underestimated. MERS-CoV could therefore adapt to human transmission in Africa rather than the Arabian Peninsula, where attention is currently focused. FUNDING: The National Science and Technology Major Project, National Institutes of Health.

Prolonged viral RNA shedding and recurrence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in coronavirus disease 2019 (COVID-19) patients have been reported. However, the clinical outcome and pathogenesis remain unclear. In this study, we recruited 43 laboratory-confirmed COVID-19 patients. We found that prolonged viral RNA shedding or recurrence mainly occurred in severe/critical patients (P

AIM To compare and assess T1rho values of the femorotibial cartilage compartments and subregional menisci in patients with hyperuricaemia at 3 T. MATERIALS AND METHODS Thirty-two patients were enrolled in the study and were subdivided into two subgroups: 15 healthy controls (three women, 12 men; mean age = 45.3 ± 10.9 years, age range 25–72 years) and 17 patients with asymptomatic hyperuricaemia (two women, 15 men; mean age = 44.4 ± 12.7 years, age range 26–77 years). All patients were evaluated using 3 T magnetic resonance imaging (MRI) using an eight-channel phased-array knee coil (transmit–receive). Wilcoxon's rank sum test and analysis of covariance (ANCOVA) were conducted to determine whether there were any statistically significant differences in the T1rho values of the femorotibial cartilage compartments and subregional menisci between the two subgroups. RESULTS Lateral tibial cartilage (45.8 ± 2.9 ms) in the healthy subgroup had significantly lower (p

We propose a nanogap-enhanced phase-change waveguide with silicon PIN heaters. Thanks to the enhanced light-matter interaction in the nanogap, the proposed structure exhibits strong attenuation (Δα = ∼35 dB/µm) and optical phase (Δneff = ∼1.2) modulation at λ = 1550 nm when achieving complete phase transitions. We further investigate two active optical devices based on the proposed waveguide, including an electro-absorption modulator and a 1 × 2 directional-coupler optical switch. Finite-difference time-domain simulation of the proposed modulator shows a high extinction ratio of ∼17 dB at 1550 nm with an active segment of volume only ∼0.004λ3. By exploiting a directional coupler design, we present a 1 × 2 optical switch with an insertion loss of < 4 dB and a compact coupling length of ∼ 15 µm while maintaining small crosstalk less than −7.2 dB over an optical bandwidth of 50 nm. Thermal analysis shows that a 10 V pulse of 30 ns (1×1 modulator) and 55 ns (1×2 switch) in duration is required to raise the GST temperature of the phase-change waveguide above the melting temperature to induce the amorphization; however, the complete crystallization occurs by applying a 5 V pulse of 180 ns (1×1 modulator) and a 6 V pulse of 200 ns (1×2 switch), respectively.

The outbreak of the novel coronavirus disease (COVID‐19) quickly spread all over China and to more than 20 other countries. Although the virus (severe acute respiratory syndrome coronavirus [SARS‐Cov‐2]) nucleic acid real‐time polymerase chain reaction (PCR) test has become the standard method for diagnosis of SARS‐CoV‐2 infection, these real‐time PCR test kits have many limitations. In addition, high false‐negative rates were reported. There is an urgent need for an accurate and rapid test method to quickly identify a large number of infected patients and asymptomatic carriers to prevent virus transmission and assure timely treatment of patients. We have developed a rapid and simple point‐of‐care lateral flow immunoassay that can detect immunoglobulin M (IgM) and IgG antibodies simultaneously against SARS‐CoV‐2 virus in human blood within 15 minutes which can detect patients at different infection stages. With this test kit, we carried out clinical studies to validate its clinical efficacy uses. The clinical detection sensitivity and specificity of this test were measured using blood samples collected from 397 PCR confirmed COVID‐19 patients and 128 negative patients at eight different clinical sites. The overall testing sensitivity was 88.66% and specificity was 90.63%. In addition, we evaluated clinical diagnosis results obtained from different types of venous and fingerstick blood samples. The results indicated great detection consistency among samples from fingerstick blood, serum and plasma of venous blood. The IgM‐IgG combined assay has better utility and sensitivity compared with a single IgM or IgG test. It can be used for the rapid screening of SARS‐CoV‐2 carriers, symptomatic or asymptomatic, in hospitals, clinics, and test laboratories.

SARS-CoV-2 caused a major outbreak of severe pneumonia (COVID-19) in humans. Viral RNA was detected in multiple organs in COVID-19 patients. However, infectious SARS-CoV-2 was only isolated from respiratory specimens. Here, infectious SARS-CoV-2 was successfully isolated from urine of a COVID-19 patient. The virus isolated could infect new susceptible cells and was recognized by its’ own patient sera. Appropriate precautions should be taken to avoid transmission from urine.

Middle East respiratory syndrome (MERS) is a highly lethal respiratory disease caused by a novel betacoronavirus (MERS coronavirus, MERS-CoV). Since its first emergence in 2012, multiple transmission events of MERS-CoV (dromedary to human and human to human) have been reported, indicating that MERS-CoV has the potential to cause widespread outbreak. However, the epidemiology of MERS as well as immune responses against the virus in animal models and patients are still not well understood, hindering the vaccine and therapeutic developments. In this review, we summarize recent genetic and epidemic findings of MERS-CoV and the progress in animal model development, immune response studies in both animals and humans. At last, we discussed the breakthrough on vaccine and therapeutic development which are important against potential future MERS outbreak.

Rapalogs, inhibitors of mTORC1 (mammalian target of rapamycin complex 1), increase life span and delay age-related phenotypes in many species. However, the molecular mechanisms have not been fully elucidated. We determined gene expression changes comparing 6- and 24-month-old rats in the kidney, liver, and skeletal muscle, and asked which of these changes were counter-regulated by a clinically-translatable (short-term and low-concentration) treatment, with a rapalog (RAD001). Surprisingly, RAD001 had a more pronounced effect on the kidney under this regimen in comparison to the liver or skeletal muscle. Histologic evaluation of kidneys revealed that the severity of chronic progressive nephropathy lesions was lower in kidneys from 24-month-old rats treated with RAD001 compared with vehicle. In addition to other gene expression changes, c-Myc, which has been shown to regulate aging, was induced by aging in the kidney and counter-regulated by RAD001. RAD001 caused a decrease in c-Myc protein, which could be rescued by a proteasome inhibitor. These findings point to settings for use of mTORC1 inhibitors to treat age-related disorders, and highlight c-Myc regulation as one of the potential mechanisms by which mTORC1 inhibition is perturbing age-related phenotypes.

Metasurfaces offer a unique platform to realize flat lenses, reducing the size and complexity of imaging systems and thus enabling new imaging modalities. In this paper, we designed a bilayer helicity-dependent continuous varifocal dielectric metalens in the near-infrared range. The first layer consists of silicon nanopillars and functions as a half-wave plate, providing the helicity-dependent metasurface by combining propagation phase and geometric phase. The second layer consists of phase-change material Sb2S3 nanopillars and provides tunable propagation phases. Upon excitation with the circularly polarized waves possessing different helicities, the metalens can generate helicity-dependent longitudinal focal spots. Under the excitation of linear polarized light, the helicity-dependent dual foci are generated. The focal lengths in this metalens can be continuously tuned by the crystallization fraction of Sb2S3. The zoom range is achieved from 32.5 µm to 37.2 µm for right circularly polarized waves and from 50.5 µm to 60.9 µm for left circularly polarized waves. The simulated focusing efficiencies are above 75% and 87% for the circularly and linearly polarized waves, respectively. The proposed metalens has potential applications in miniaturized devices, including compact optical communication systems, imaging, and medical devices.

Background: The gut microbiome represents a niche for biomarkers discovery to risk-stratify MAFLD patients. However, each population may have unique microbiome signatures and studies are needed in Latin America where MAFLD prevalence and severity are high. Aims: To identify gut metatranscriptome and metabolome signatures associated with MAFLD and steatohepatitis (SH) in Argentina. Methods: Stool samples, diet, demographic and clinical data were obtained from 33 biopsy-proven patients (12 simple steatosis -SS- and 21 SH) and 19 healthy volunteers (HV). PNPLA3 rs738409 SNP was genotyped. HPLC, flow injection analysis with MS/MS in tandem and MetaboAnalyst-v4.0 were used for metabolomics. RNA-seq was performed in NovaSeq6000®. bioBakery-v1.8 and Maaslin2-v1.2.0 were used for data analysis. Results: BMI was higher in MAFLD patients, particularly in SH (q=4.49e-06). After adjusting for BMI, 89 and 53 gene family clusters were differentially expressed between HV and MAFLD and between SS and SH, respectively (q

To design and implement a simulated blood flow velocity measurement system via very-high-frequency (VHF)ultrasound, which can be used to complete an experimental study that simulates the real-time detection of blood flow information from human superficial organs. We prepared a blood phantom that was composed of nylon particles, pure water, glycerol, dextran and non-ionic surfactant. The experimental platform of this system included a simulated blood circulation system consisting of a medical injection pump for controlling the flow velocity, a medical silicone tube, and a simulated blood phantom; a single pulse, mechanical, linear scanning probe with an operation frequency of 50 MHz; the ultrasound echo signal acquisition circuit of the slave computer; and the VHF ultrasound blood flow imaging system composed of the host computer modules. The transducer was placed approximately 9 mm above the simulated blood vessel, and the direction of blood flow was same to the scanning direction of the probe. The pushing speed of the injection pump was adjusted to obtain the simulated blood imaging near the focal area. The acoustic characteristics of the homemade blood phantom were nearly unchanged for 150 days, which met the requirements of experimental research. According to the imaging results of the simulated blood flow at various flow velocities, the red blood cell imaging particles are large and the number is small when the flow velocity is low, and the red blood cell imaging particles are small and the number is large when the flow velocity is high. The directly proportional relationship between the number of red blood cell imaging particles of the simulated blood and the blood flow velocity can preliminarily be obtained by the designed blood flow velocity measurement system via VHF ultrasound, and the blood flow velocity can be determined accordingly.

Nitrogen (N) is one of the macronutrients required for plant growth, and reasonable application of N fertilizers can increase crop yields and improve their quality. However, excessive application of N fertilizers will decrease N use efficiency and also lead to increases in N2O emissions from agricultural soils and many other environmental issues. Research on the effects of different N fertilizer management practices on wheat yields and N2O emissions will assist the selection of effective N management measures which enable achieving high wheat yields while reducing N2O emissions. To investigate the effects of different N management practices on wheat yields and soil N2O emissions, we conducted field trials with 5 treatments of no N fertilizer (CK), farmers common N rate (AN), optimal N rate (ON), 20% reduction in optimal rate+dicyandiamide (ON80%+DCD), 20% reduction in optimal rate+nano-carbon (ON80%+NC). The static closed chamber gas chromatography method was used to monitor N2O emissions during the wheat growing season. The results showed that there were obvious seasonal characteristics of N2O emissions under each treatment and N2O emissions were mainly concentrated in the sowing-greening stage, accounting for 54.6–68.2% of the overall emissions. Compared with AN, N2O emissions were decreased by 23.1, 45.4 and 33.7%, respectively, under ON, ON80%+DCD and ON80%+NC, and emission factors were declined by 22.2, 66.7 and 33.3%, respectively. Wheat yield was increased significantly under ON80%+DCD and ON80%+NC by 12.3 and 11.9%, respectively, relative to AN while there was no significant change in yield in the ON treatment. Compared with ON, overall N2O emissions were decreased by 29.1 and 13.9% while wheat yields improved by 18.3 and 17.9% under ON80%+DCD and ON80%+NC, respectively. We therefore recommend that ON80%+DCD and ON80%+NC be referred as effective N management practices increasing yields while mitigating emissions.

This paper introduces the concept of distributed generation resources and smart grid, and analyzes the impact of distributed generation parallel operation on three aspects of network loss, voltage and relay protection.

AIM To evaluate the role of MRI in preoperative assessments of patients with a persistent cloaca and compare magnetic resonance imaging (MRI) versus fluoroscopy contrast study in the accuracy of common canal measurement and classification prediction. MATERIALS AND METHODS Thirty-one patients with a persistent cloaca were diagnosed and treated at Guangzhou Women and Children's Medical Center between March 2011 and December 2017. The length of the common canal was measured using MRI and fluoroscopy contrast study. Classification results based on measurements were compared with cystoscopy and intraoperative findings. The accuracy in predicting the classification by measuring the common canal length was compared. RESULT Among 31 patients, 24 had MRI, 24 underwent fluoroscopy contrast study, and 25 underwent cystoscopy. In 20 patients, MRI-based categorisations were in accordance with cystoscopy or surgery findings, whereas in four patients there was discordance. In 17 patients, categorisations based on fluoroscopy contrast study were in accordance with cystoscopy or surgery findings, and in seven patients there was discordance; the difference was not statistically significant (p>0.05). CONCLUSION MRI may accurately demonstrate genitourinary anomalies and the length of the common canal in patients with persistent cloaca. Categorisation based on MRI measurements of the common canal was accordant with the results from cystoscopy and findings from surgery. The use of this method may help surgeons to develop appropriate reconstruction plans before sending their patients to the operating room.

The key parameters for structural characteristics of shield tunnel machine's cutter head were selected based upon some typical structures used in the design of cutter heads. Then a new parametric model generation program of finite elements numerical model in ANSYS' APDL language was developed for the further analysis. The program can automatically generate a parametric finite elements model of shield cutter head to use in the analysis of the strength and stiffness of shield cutter head.

Analysis, evaluation and interpretation of measured signals become important components in engineering research and practice, especially for material characteristic parameters which can not be obtained directly by experimental measurements. The present paper proposes a hybrid-inverse analysis method for the identification of the nonlinear material parameters of any individual component from the mechanical responses of a global composite. The method couples experimental approach, numerical simulation with inverse search method. The experimental approach is used to provide basic data. Then parameter identification and numerical simulation are utilized to identify elasto-plastic material properties by the experimental data obtained and inverse searching algorithm. A numerical example of a stainless steel clad copper sheet is considered to verify and show the applicability of the proposed hybrid-inverse method. In this example, a set of material parameters in an elasto-plastic constitutive model have been identified by using the obtained experimental data.

Cervical spondylosis is a disease that is a cervical intervertebral joints (disc, facet joint hook, facet joints) degeneration, involving the nerve (nerve root, spinal cord, sympathetic), vascular (before spinal artery, vertebral artery) and a corresponding clinical manifestations (symptoms and signs) [1], more common in middle-aged crowd. With the increase of learning and work tasks, age of onset of cervical disease gradually tend to be younger. Young patients accounted for 12% of patients with cervical about, which than in previous years was significantly increased. With the main part of the cervical neck and shoulder exercises by surrounding the cervical muscles, ligaments vasomotor workout, which can improve muscle strength and joint mobility cervical spine. This study was to explore the impact of cervical exercises for the rehabilitation of patients with cervical college students, to explore a more simple and comprehensive, secure and reliable method for the prevention and treatment of cervical disease.

To provide theoretical basis for the fitness value of spinal exercise by studying the influence of the spine exercise on multifidus muscle of lumbosacral. Selected 30 exercisers randomly which those age between 45-70 years on the basis of the normal physical activity remains the same, for at least four times a week spine exercises practitioners 15 people as experimental group, and the rest of the control group. Practice before 6 months after lumbar flexion buckling and straight average recorded in the process of electricity (ASEMG) and the average ratio (FER) electrical values on flexion and extension. The experimental group’s ASEMG and FER of multifidus muscle of lumbosacral more significant differences before and after exercise. The spine exercise can increase the multifidus muscle function effectively. KEYWORD: spine exercise; Multifidus Muscle; function International Conference on Social Science, Education Management and Sports Education (SSEMSE 2015) © 2015. The authors Published by Atlantis Press 418

The requirements of acoustic output parameters in clinical instruments are very strict. This paper proposed a method that introducing the Golay complementary coded excitation and decoded compression to ophthalmological ultrasound biometer, instead of the traditional one using one pulse excitation. By adopting this method, the excitation voltage can be cut down from 60 V to ±15 V. Thus, the ultrasonic instantaneous excitation power was reduced greatly, and in the meantime the average excitation power was enhanced. A one reflection experiment, a resolution measurement experiment and in vivo experiment were designed in this paper. The results showed that when cutting down the excitation voltage but using Golay-coded pulse excitation can also maintain the same detective depth, signal intensity, resolution and measuring accuracy as the high excitation voltage.

To design a Fast Fourier Transform (FFT) processor to meet the needs for high-speed and real-time signal processing. A 1024-point, 32-bit, fixed, complex FFT processor is designed based on a field programmable gate array (FPGA) by using the radix-2 decimation in frequency (DIF) algorithm and the pipeline structure in the butterfly module and the ping-pone operation in data storage unit. When the primary clock is 100 MHz, the 1024-point FFT calculation takes about 62.95 us. The processor is fast enough for processing the high-speed and real time signals. The result provides reference values that theoretical study of the FFT algorithm can be applied into the adaptive dynamic filter of an ultrasonic diagnostic system and an ultrasonic Doppler flow measurement system.

For the estimation of block-motion vectors, common techniques use uniform pixel-decimation patterns to select pixels to evaluate block-matching criterion, while other techniques use adaptive pixel patterns and have achieved better efficiency. However, these adaptive techniques still require an initial division of a block into a set of uniform regions, and therefore, are locally adaptive in essence. Our proposed scheme, which does not fix any regions at the beginning and selects pixels only when they have the features important in determining a match, shows an improvement in performance over the existing adaptive schemes. Our results suggest the usefulness of this method in block-motion estimation for low-bit-rate video coding, particularly in video phone and video conferencing.

A new self-adaptive dynamic filter in ultrasound imaging system was proposed to match the center frequency of the dynamic filter and the real echo in real time. The fast Fourier transform (FFT) processor was used to analyze each small section of the echoes and the factors of the filters in the self-adaptive mechanism were decided by the frequency characteristic of the real echoes. The realization of the system was based on the field programmable gate array (FPGA). The timing simulation was analyzed and carried on by Modelsim which was dealing with sinusoidal signals doped with white noise. The simulation results showed that the self-adaptive dynamic could reduce the noise effectively as this method could match the center frequency of the near field and far field real echoes precisely. The new self-adaptive dynamic filter is fast enough for processing high-speed and real-time signals, providing one basis for designing the filters in ultrasonography.

The authors developed an efficient semiautomatic tissue classifier for X-ray computed tomography (CT) images which can be used to build patient- or animal-specific finite element (FE) models for bioelectric studies. The classifier uses a gray scale histogram for each tissue type and three-dimensional (3-D) neighborhood information. A total of 537 CT images from four animals (pigs) were classified with an average accuracy of 96.5% compared to manual classification by a radiologist. The use of 3-D, as opposed to 2-D, information reduced the error rate by 78%. Models generated using minimal or full manual editing yielded substantially identical voltage profiles. For the purpose of calculating voltage gradients or current densities in specific tissues, such as the myocardium, the appropriate slices need to be fully edited, however. The authors' classifier offers an approach to building FE models from image information with a level of manual effort that can be adjusted to the need of the application.

This study aimed to obtain the ultrasonic echo images with the best resolution in all detective depth. A dynamic filter was designed based on field programmable gate array (FPGA). The detective depth of the digital B mode ultrasonography was divided into 64 segments, and sixty four 32-step band-pass filters were adopted to complete the process of the dynamic filtering of human ultrasonic echo signals. Then the design was applied to the digital B mode ultrasonography with 128-elements and the center frequency of 3.5 MHz. With the experiments in tissue mimicking ultrasound phantom, the detective depth, the resolution in far field and the denoising ability were all obviously improved compared with the image created by using the constant filter.

This paper presents a mechanical model to predict the operational loads acting on the cutter head of shield tunnel machine during excavation based on contact mechanics theory, in which the cutter head is considered as a rigid cylinder punch and the soil to be excavated is simplified as an elastic half-space. Then the estimation formulae of the operational loads are obtained and the influence of some key factors including the geological parameters, the radius of the cutter head and especially the excavation penetration can be analyzed based on the proposed model. The results show that the operational loads increase linearly when the machine works with a deeper excavation penetration. The prediction presented in this paper agrees with experimental results given by other researcher. It also can be seen that the geological condition affects both the quantity and the changing rate of loads with the excavation penetration. The proposed model may be a possible and feasible way to predict loads of shield tunnel machine.

A dual smooth TCP congestion control algorithm based on AIMD (SAISD) is presented. SAISD uses a decreasing function as the incremental in the speed of sending, and when the congestion is detected, the current sending rate is changed smoothly refered the historical value of cwnd, thus the oscillatory of sending speed is improved. The simulation results show that when the UDP and TCP co-exist, SAISD provides a smooth services for UDP, and it has good fairness and stability, meanwhile it can improve the utilization of bandwidth.

Analysis, evaluation and interpretation of measured signals become important components in engineering research and practice, especially for those material characteristic parameters which can not be obtained directly by experimental measurements. The present paper proposes a hybrid-inverse analysis method to the identification of the nonlinear material parameters of any individual component from the mechanical responses of a global composite. The method couples experimental approach, numerical simulation with inverse search method. The experimental approach is used to provide basic data which parameter identification and numerical simulation is utilized to identify elasto-plastic material properties by means of experimental data obtained and inverse searching algorithm. A numerical example of a stainless steel clad copper sheet is considered to verify and show the applicability of the proposed hybrid-inverse method. In this example, a set of material parameters in an elasto-plastic constitutive model have been identified by using the obtained experimental data.

Eyes require a high resolution scan image. The authors have developed a series of 10 MHz ultrasonic A/B scanners for ophthalmology which can be used to diagnose diseases of the eye and measure axial length. Vertical resolution of B images is less than 0.5 mm. Lateral resolution is less than 1.0 mm. Precision of biometry measurement is 0.1 mm. These instruments have been getting a wide use in over 300 hospitals in China.

Background mRNA profiling has become an important tool for developing and validating prognostic assays predictive of disease treatment response and outcome. Archives of annotated formalin-fixed paraffin-embedded tissues (FFPET) are available as a potential source for retrospective studies. Methods are needed to profile these FFPET samples that are linked to clinical outcomes to generate hypotheses that could lead to classifiers for clinical applications. Methods We developed a two-color microarray-based profiling platform by optimizing target amplification, experimental design, quality control, and microarray content and applied it to the profiling of FFPET samples. We profiled a set of 50 fresh frozen (FF) breast cancer samples and assigned class labels according to the signature and method by van 't Veer et al [1] and then profiled 50 matched FFPET samples to test how well the FFPET data predicted the class labels. We also compared the sorting power of classifiers derived from FFPET sample data with classifiers derived from data from matched FF samples. Results When a classifier developed with matched FF samples was applied to FFPET data to assign samples to either "good" or "poor" outcome class labels, the classifier was able to assign the FFPET samples to the correct class label with an average error rate = 12% to 16%, respectively, with an Odds Ratio = 36.4 to 60.4, respectively. A classifier derived from FFPET data was able to predict the class label in FFPET samples (leave-one-out cross validation) with an error rate of ~14% (p-value = 3.7 × 10-7). When applied to the matched FF samples, the FFPET-derived classifier was able to assign FF samples to the correct class labels with 96% accuracy. The single misclassification was attributed to poor sample quality, as measured by qPCR on total RNA, which emphasizes the need for sample quality control before profiling. Conclusion We have optimized a platform for expression analyses and have shown that our profiling platform is able to accurately sort FFPET samples into class labels derived from FF classifiers. Furthermore, using this platform, a classifier derived from FFPET samples can reliably provide the same sorting power as a classifier derived from matched FF samples. We anticipate that these techniques could be used to generate hypotheses from archives of FFPET samples, and thus may lead to prognostic and predictive classifiers that could be used, for example, to segregate patients for clinical trial enrollment or to guide patient treatment.