Review of Methods Used for Microalgal Lipid-Content Analysis

AbstractThis paper provides a brief overview of most recent strategies that used to analyze microalgal lipid content, including NIR spectroscopy and TD-NMR methods etc. Common methods like gravimetric quantification and staining quantification are also introduced in this report. The physiology background of microalgal lipid accumulation is stated in order to clarify the purpose of each individual analytical method. After all, online lipid content measurement method that has good accuracy has the best chance to be generalized for all the lipid analyzing researches

Effect of task type on the use of discourse markers in L2 Portuguese by L1 Chinese learners

In an attempt to analyze the effect of different oral tasks on the use of discourse markers (DMs) in second language (L2) Portuguese by first language (L1) Chinese speakers at different L2 proficiency levels, the current study is oriented by two research questions: (1) in what way does L2 proficiency of L1 Chinese speakers influence the use of DMs in Portuguese across tasks in terms of the frequency and variety of different DM classes? (2) how does oral task type affect the use of DMs by L1 Chinese speakers of L2 Portuguese in terms of the frequency and variety of different DM classes? Data for the present study were collected by using two oral tasks, conversation task and narrative task, conducted by 12 Chinese speakers of Portuguese at a lower and higher L2 proficiency levels. Results showed that the Chinese speakers tended to use the DMs in L2 Portuguese at a higher rate and wider variety when they were asked to perform the conversation task and the use of some DM categories seems not to stay correlated with the L2 proficiency levels across tasks.Tendo como objetivo analisar o efeito das diferentes tarefas orais sobre o uso de Marcadores Discursivos (MDs) em Português como Língua Segunda (L2) por aprendentes chineses em diferentes níveis de proficiência, o presente estudo é orientado por duas questões de pesquisa: (1) de que maneira é que o nível de proficiência dos aprendentes chineses influencia o uso dos MDs em L2 português perante diferentes tarefas orais relativamente à frequência e à variedade? (2) como é que o tipo de tarefa influencia o uso dos MDs por aprendentes chineses no que diz respeito à frequência e à variedade dos MDs pertencentes às diferentes categorias? Os dados usados neste estudo foram recolhidos a partir de duas tarefas orais, conversa e narrativa, cumpridas por 12 aprendentes chineses com L2 português em diferentes níveis de proficiência. Os resultados mostraram que os aprendentes chineses tenderam a usar os MDs em L2 português com uma maior frequência e variedade na tarefa de conversa e parece que não há uma correlação entre o uso de algumas categorias de MD e o nível de proficiência em L2

Inverse Kinematic Analysis and Evaluation of a Robot for Nondestructive Testing Application

The robot system has been utilized in the nondestructive testing field in recent years. However, only a few studies have focused on the application of ultrasonic testing for complex work pieces with the robot system. The inverse kinematics problem of the 6-DOF robot should be resolved before the ultrasonic testing task. A new effective solution for curved-surface scanning with a 6-DOF robot system is proposed in this study. A new arm-wrist separateness method is adopted to solve the inverse problem of the robot system. Eight solutions of the joint angles can be acquired with the proposed inverse kinematics method. The shortest distance rule is adopted to optimize the inverse kinematics solutions. The best joint-angle solution is identified. Furthermore, a 3D-application software is developed to simulate ultrasonic trajectory planning for complex-shape work pieces with a 6-DOF robot. Finally, the validity of the scanning method is verified based on the C-scan results of a work piece with a curved surface. The developed robot ultrasonic testing system is validated. The proposed method provides an effective solution to this problem and would greatly benefit the development of industrial nondestructive testing

Characteristic Evaluation on Bolt Stress by Ultrasonic Nondestructive Methods

Based on the acoustoelasticity theory, a certain relationship exists between ultrasonic velocity and stress. By combining shear and longitudinal waves, this paper provides a nondestructive method of evaluating axial stress in a tightened bolt. For measuring the bolt axial stress in different situations, such as under low or high loads, this paper provides guidelines for calculating the stress for a given load factor. Experimental and calculated results were compared for three bolt test samples: an austenitic stainless steel bolt (A2-70) and low-carbon steel 4.8 and 8.8 bolts. On average, the experimental results were in good agreement with those obtained through calculations, thus providing a nondestructive method for bolt stress measurements

Characteristic Evaluation on Bolt Stress by Ultrasonic Nondestructive Methods

Based on the acoustoelasticity theory, a certain relationship exists between ultrasonic velocity and stress. By combining shear and longitudinal waves, this paper provides a nondestructive method of evaluating axial stress in a tightened bolt. For measuring the bolt axial stress in different situations, such as under low or high loads, this paper provides guidelines for calculating the stress for a given load factor. Experimental and calculated results were compared for three bolt test samples: an austenitic stainless steel bolt (A2-70) and low-carbon steel 4.8 and 8.8 bolts. On average, the experimental results were in good agreement with those obtained through calculations, thus providing a nondestructive method for bolt stress measurements

Human Norovirus NTPase Antagonizes Interferon-β Production by Interacting With IkB Kinase ε.

Human norovirus (HuNoV) is the leading cause of epidemic acute gastroenteritis worldwide. Type I interferons (IFN)-α/β are highly potent cytokines that are initially identified for their essential roles in antiviral defense. It was reported that HuNoV infection did not induce IFN-β expression but was controlled in the presence of IFN-β in human intestinal enteroids and a gnotobiotic pig model, suggesting that HuNoV has likely developed evasion countermeasures. In this study, we found that a cDNA clone of GII.4 HuNoV, the predominantly circulating genotype worldwide, inhibits the production of IFN-β and identified the viral NTPase as a key component responsible for such inhibition. HuNoV NTPase not only inhibits the activity of IFN-β promoter but also the mRNA and protein production of IFN-β. Additional studies indicate that NTPase inhibits the phosphorylation and nuclear translocation of interferon-regulatory factor-3 (IRF-3), leading to the suppression of IFN-β promoter activation. Mechanistically, NTPase interacts with IkB kinase ε (IKKε), an important factor for IRF-3 phosphorylation, and such interaction blocks the association of IKKε with unanchored K48-linked polyubiquitin chains, resulting in the inhibition of IKKε phosphorylation. Further studies demonstrated that the 1-179 aa domain of NTPase which interacts with IKKε is critical for the suppression of IFN-β production. Our findings highlight the role of HuNoV NTPase in the inhibition of IFN-β production, providing insights into a novel mechanism underlying how HuNoV evades the host innate immunity

Herpes Simplex Virus Type 2 Infection-Induced Expression of CXCR3 Ligands Promotes CD4(+) T Cell Migration and Is Regulated by the Viral Immediate-Early Protein ICP4

HSV-2 infection-induced CXCR3 ligands are important for the recruitment of virus-specific CD8+ T cells, but their impact on CD4+ T cell trafficking remains to be further determined. Given that recruitment of CD4+ T cells to infection areas may be one of the mechanisms that account for HSV-2 infection-mediated enhancement of HIV-1 sexual transmission, here we investigated the functionality of HSV-2 infection-induced CXCR3 ligands CXCL9, CXCL10, and CXCL11 in vivo and in vitro, and determined the viral components responsive for such induction and the underlying mechanisms. We first found that the expression of CXCR3 ligands CXCL9, CXCL10, and CXCL11 was increased in mice following vaginal challenge with HSV-2, while CXCL9 played a predominant role in the recruitment of CD4+ T cells to the vaginal foci of infected mice. HSV-2 infection also induced the production of CXCL9, CXCL10, and CXCL11 in human cervical epithelial cells. Of note, although HSV-2 induced the expression of all the three CXCR3 ligands, the induced CXCL9 appeared to play a predominant role in promoting CD4+ T cell migration, reflecting that the concentrations of CXCL10 and CXCL11 required for CD4+ T cell migration are higher than that of CXCL9. We further revealed that, ICP4, an immediate-early protein of HSV-2, is crucial in promoting CXCR3 ligand expression through the activation of p38 MAPK pathway. Mechanistically, ICP4 binds to corresponding promoters of CXCR3 ligands via interacting with the TATA binding protein (TBP), resulting in the transcriptional activation of the corresponding promoters. Taken together, our study highlights HSV-2 ICP4 as a vital viral protein in promoting CXCR3 ligand expression and CXCL9 as the key induced chemokine in mediating CD4+ T cell migration. Findings in this study have shed light on HSV-2 induced leukocyte recruitment which may be important for understanding HSV-2 infection-enhanced HIV-1 sexual transmission and the development of intervention strategies

DC-SIGN as an attachment factor mediates Japanese encephalitis virus infection of human dendritic cells via interaction with a single high-mannose residue of viral E glycoprotein

AbstractThe skin-resident dendritic cells (DCs) are thought to be the first defender to encounter incoming viruses and likely play a role in Japanese encephalitis virus (JEV) early infection. In the current study, following the demonstration of JEV productive infection in DCs, we revealed that the interaction between JEV envelope glycoprotein (E glycoprotein) and DC-SIGN was important for such infection as evidenced by antibody neutralization and siRNA knockdown experiments. Moreover, the high-mannose N-linked glycan at N154 of E glycoprotein was shown to be crucial for JEV binding to DC-SIGN and subsequent internalization, while mutation of DC-SIGN internalization motif did not affect JEV uptake and internalization. These data together suggest that DC-SIGN functions as an attachment factor rather than an entry receptor for JEV. Our findings highlight the potential significance of DC-SIGN in JEV early infection, providing a basis for further understanding how JEV exploits DC-SIGN to gain access to dendritic cells

Identification of anthropogenic parameters for a regional nitrogen balance model via field investigation of six ecosystems in China

To evaluate the impact of human behavior (with regard food consumption, waste disposal and farming method) on nitrogen flow, a field investigation was conducted in six typical ecosystems in China. A number of parameters for regional nitrogen balance models were identified during the investigation. The results show that the average per-capita daily protein intake is 107 g. While there is an insignificant difference in total protein intake among the different ecosystems, protein intake from all food groups, except for eggs, is significantly different (P a parts per thousand currency sign 0.05). Differences in diet, along with those in socio-economic conditions, reflect differences in the characteristics of the ecosystems. Regarding per-capita annual potential nitrogen loading from human excrement, a considerable difference exists between the urban rich and the rural poor. In urban areas, approximately 1.02 kg N is returned to farmlands and 5.49 kg N is directly discharged into rivers. In rural regions, on the other hand, approximately 4.33 kg N is returned to farmlands and 1.60 kg N is directly discharged into rivers. Furthermore, urea and mixed fertilizers constitute the most common chemical fertilizers in the study area. Fertilizer diversification is practiced in a range of agricultural lands, paddy-fields and irrigated plains. In the oasis and paddy-field agricultural systems, many of the agricultural by-products (e.g., straw) are burned or mixed with base-fertilizers and plowed into the soil. In irrigated agricultural systems, over 70% of agricultural by-products are recycled as livestock feed. In most instances, livestock excrement is directly reduced in the pasturelands or reused in the fields as manure. Occasionally, as in the case of large-scale breeding, excrements are usually abandoned

DC-SIGN promotes Japanese encephalitis virus transmission from dendritic cells to T cells via virological synapses.

Skin-resident dendritic cells (DCs) likely encounter incoming viruses in the first place, and their migration to lymph nodes following virus capture may promote viral replication. However, the molecular mechanisms underlying these processes remain unclear. In the present study, we found that compared to cell-free viruses, DC-bound viruses showed enhanced capture of JEV by T cells. Additionally, JEV infection was increased by co-culturing DCs and T cells. Blocking the C-type lectin receptor DC-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) with neutralizing antibodies or antagonists blocked JEV transmission to T cells. Live-cell imaging revealed that DCs captured and transferred JEV viral particles to T cells via virological synapses formed at DC-T cell junctions. These findings indicate that DC-SIGN plays an important role in JEV transmission from DCs to T cells and provide insight into how JEV exploits the migratory and antigen-presenting capabilities of DCs to gain access to lymph nodes for dissemination and persistence in the host