Antiviral effect of baicalin phospholipid complex against duck hepatitis A virus type 1

Duck hepatitis A virus type 1 (DHAV-1) is one of the main pathogens of ducklings and causes a high mortality rate. Baicalin (BA) has potent antiviral effect, but the solubility is very poor. In order to increase the absorption, solubility, and pharmacological activity, the phospholipid complex was used to modify BA in present study. Therefore, BA phospholipid complex (BAPC) was prepared. The anti-DHAV-1 abilities of BA and BAPC in vitro was evaluated by cell counting kit-8 and reverse transcription quantitative PCR. The curative effects of BA and BAPC on ducklings which were infected by DHAV-1 in addition to the ALT and AST levels were also detected. The results indicated the anti-DHAV-1 ability of BAPC was stronger than that of BA both in vitro and in vivo. To explore the anti-DHAV-1 mechanism, the influence of BAPC on DHAV-1 adsorption, replication, and release was studied. Furthermore, the anti-oxidative and immuno-enhancing abilities of BAPC in the treatment of infected ducklings were also determined. The results showed BAPC inhibited DHAV-1 adsorption, replication and release. Furthermore, it played anti-oxidative and immno-enhancing roles in the treatment, and the immno-enhancing role was crucial to the treatment.

A free-standing wire scattering technique to monitor calibration variations of the DIII-D density profile reflectometer

Real-time phase calibration of the ITER profile reflectometer is essential due to the long plasma duration and expected waveguide path length changes during a discharge. Progress has been recently made in addressing this issue by employing a phase calibration technique on DIII-D that monitors calibration variations that occur during each plasma discharge. By installing a thin free-standing metallic wire (1 mm diameter) near the end of the overmoded waveguide transmission system (oriented perpendicular to the waveguide axis), the round-trip phase shift from the wire is detected simultaneously with the plasma phase shifts. Variations in the reflectometer round trip path length (∼26 m) are then calculated after each DIII-D plasma discharge, allowing the calibration phase to be accurately monitored and updated. The round-trip reflectometer path length is observed to vary by ∼3 mm (root mean square value) during a typical DIII-D discharge. Using the variations in calibration phase, the density profile measurement accuracy can be improved. Since the wire retro-reflected power is ∼0.01 of the plasma signal, minimal effect is observed on the reflected signal from the plasma. Importantly, through a suitable choice in wire diameter, the calibration signal can be made approximately independent of the V-band reflectometer launch polarization. This is particularly important on DIII-D since orthogonal X- and O-mode polarized beams are coupled into the same transmission waveguide and launch antenna.

Biology of Oral Streptococci

Bacteria belonging to the genus Streptococcus are the first inhabitants of the oral cavity, which can be acquired right after birth and thus play an important role in the assembly of the oral microbiota. In this article, we discuss the different oral environments inhabited by streptococci and the species that occupy each niche. Special attention is given to the taxonomy of Streptococcus, because this genus is now divided into eight distinct groups, and oral species are found in six of them. Oral streptococci produce an arsenal of adhesive molecules that allow them to efficiently colonize different tissues in the mouth. Also, they have a remarkable ability to metabolize carbohydrates via fermentation, thereby generating acids as byproducts. Excessive acidification of the oral environment by aciduric species such as Streptococcus mutans is directly associated with the development of dental caries. However, less acid-tolerant species such as Streptococcus salivarius and Streptococcus gordonii produce large amounts of alkali, displaying an important role in the acid-base physiology of the oral cavity. Another important characteristic of certain oral streptococci is their ability to generate hydrogen peroxide that can inhibit the growth of S. mutans. Thus, oral streptococci can also be beneficial to the host by producing molecules that are inhibitory to pathogenic species. Lastly, commensal and pathogenic streptococci residing in the oral cavity can eventually gain access to the bloodstream and cause systemic infections such as infective endocarditis.

Genetic contribution of suppressor of cytokine signalling polymorphisms to the susceptibility to infection after traumatic injury

Suppressor of cytokine signalling (SOCS) proteins are crucial negative regulators in many signalling pathways and are implicated in the pathogenesis of infectious diseases. The purpose of this study was to uncover possible associations of common polymorphisms within SOCS genes with infectious outcomes after traumatic injury. A total of 1087 trauma patients (Chongqing cohort 806 and Yunnan cohort 281) were recruited and followed-up for the development of infectious outcomes, such as sepsis and multiple organ dysfunction syndrome (MODS). Twelve selected single nucleotide polymorphisms (SNPs) were screened by pyrosequencing to determine their genotypes and associations with infectious complications. Among the 12 selected SNPs, only the cytokine-inducible Src homology (SH2) domain protein (CISH) promoter rs414171 polymorphism was found consistently to be associated statistically with the incidence of sepsis and MOD score in the two cohorts, despite analysing the SNPs independently or in combination. Further, patients with a T allele had significantly lower CISH expression and lower production of tumour necrosis factor (TNF)-α, but higher production of interleukin (IL)-10. Luciferase assay confirmed that the A→T variant in the rs414171 polymorphism inhibited the transcriptional activities of the CISH gene significantly. The CISH rs414171 polymorphism is associated significantly with susceptibility to sepsis and MODS in traumatic patients, which might prove to be a novel biomarker for indicating risk of infectious outcomes in critically injured patients.

A colorimetric assay for vanillin detection by determination of the luminescence of o-toluidine condensates

Vanillin (4-hydroxy-3-methoxybenzaldehyde), a food additive with rich milk flavor, is commonly used in the food, beverage and cosmetic industries. However, excessive consumption of vanillin may cause liver and kidney damage. Therefore, methods for detecting and controlling the level of vanillin in food, especially in infant powder, have important practical significance. In this study, we established a colorimetric assay for vanillin detection. The detection was performed under high-temperature and acidic conditions, which can induce the reaction of the aldehyde group of vanillin with the amino group of o-toluidine. The resulting product had a maximum absorption at 363 nm, which was quantified by a UV spectrophotometer. This assay had a limit of detection (LOD) of 1 pg mL⁻¹ and a linear range between 1 μg mL⁻¹ and 100 μg mL⁻¹. The average recoveries at three spiked levels were in the range from 91.1% to 101.6% with a relative standard deviation (RSD) of 4.62% ~ 7.27%.

[Relevant factors of tinnitus in the elderly: an analysis of 150 volunteers]

Objective:To evaluate and characterize tinnitus in elderly volunteers，try to find out the relevant factors that can affect the incidence of tinnitus.Method:The study included 150 elderly volunteers. All volunteers had taken the otology examination and pure tone audiometry. They were interviewed by the investigators who were trained together, using the same questionnaire. The characteristics of tinnitus and the relationship between all relevant factors and tinnitus were analyzed.Result:Average age was 71.4 years. There are now 77 patients with tinnitus(51.3%), of which 31 cases have sustained tinnitus for more than 3 months, accounting for 40.3% of existing tinnitus volunteers. There was negative correlation between tinnitus and age. There was positive correlation between tinnitus and hearing loss. Tinnitus and headache had no correlation(P>0.05).Conclusion:After reach a certain age(70 years old), the incidence of tinnitus decreased. Hearing loss might be the most dangerous factor.If the hearing loss was more serious, the incidence of the tinnitus became higher. Tinnitus in the elderly may be the result of a combination of factors.

Quasistationary Plasma Predator-Prey System of Coupled Turbulence, Drive, and Sheared E×B Flow During High Performance DIII-D Tokamak Discharges

A new, long-lived limit cycle oscillation (LCO) regime has been observed in the edge of near zero torque high performance DIII-D tokamak plasma discharges. These LCOs are localized and composed of density turbulence, gradient drives, and E×B velocity shear damping (E and B are the local radial electric and total magnetic fields). Density turbulence sequentially acts as a predator (via turbulence transport) of profile gradients and a prey (via shear suppression) to the E×B velocity shear. Reported here for the first time is a unique spatiotemporal variation of the local E×B velocity, which is found to be essential for the existence of this system. The LCO system is quasistationary, existing from 3 to 12 plasma energy confinement times (∼30-900 LCO cycles) limited by hardware constraints. This plasma system appears to contribute strongly to the edge transport in these high performance and transient-free plasmas, as evident from oscillations in transport relevant edge parameters at LCO time scale.

[Application of gold nanoparticles-based lateral flow strip for dengue virus detection based on strand-displacement amplification]

OBJECTIVE

To investigate the rapid and accurate method for the detection of dengue virus (DENV) by using nicking enzyme assisted strand-displacement amplification (SDA) combined with gold nanoparticles-based lateral flow strip.

METHODS

Total RNA of the virus was extracted by using magnetic beads method and transcribed to cDNA for SDA detection system. Nicking enzyme-assisted method was used for detecting DENV, and agarose gel electrophoresis was used for analyzing the sensitivity of SDA amplification products. A gold nanoparticles-based lateral flow strip was developed based on the principle of nucleic acid base complementary pairing to design the test line and control line. The gold particles were prepared by using sodium citrate reduction method for gold nanoparticles-based lateral flow strip construction.

RESULTS

The sensitivity of the SDA method was 10 fmol/L, and the sensitivity of gold nanoparticles-based lateral flow strip based on SDA method was also 10 fmol/L. In a linear range from 10 fmol/L to 10¹² fmol/L, the corresponding linear correlation coefficient (R²) of DENV was 0.98. The specificity of nanoparticles-based lateral flow strip based on SDA for DENV detection was high, which was no crossing with other control groups.

CONCLUSIONS

A gold nanoparticles-based lateral flow strip based on SDA method for DENV detection has been established, which is convenient, fast, and the result is visible to naked eyes.

Four Hapten Spacer Sites Modulating Class Specificity: Nondirectional Multianalyte Immunoassay for 31 β-Agonists and Analogues

Immunoassay methods are important for monitoring β-agonists illegally used for reducing animal fat deposition in livestock. However, there is no simultaneous screening surveillance immunoassay for detecting various β-agonist chemicals that are possibly present in food. In this study, through the use of an R-(-)-salbutamol derivative as the immunizing hapten, an antibody recognizing 31 β-agonists and analogues was generated for the first time. Three-dimensional quantitative structure-activity relationship (3D QSAR) revealed that strong steric and hydrophobic fields around the hapten spacer near C-2, as well as a chirality at C-1', dominantly modulated the class specificity of the raised antibody. However, a hapten spacer linked at C-2' or C-1 would lead to a narrow specificity, and the spacer charge at C-6 could affect the raised antibody specificity spectrum. A class specificity competitive indirect enzyme-linked immunosorbent assay (ciELISA) was established with an ideal recovery ranging from 81.8 to 118.3% based on the obtained antibody. With a good agreement to the HPLC/MS method, the proposed ciELISA was confirmed to be reliable for the rapid surveillance screening assay of β-agonists in urine. This investigation will contribute to the rational design and control of the immunoassay specificity.

Antibacterial applications of graphene oxides: structure-activity relationships, molecular initiating events and biosafety

Bacterial infections may lead to diverse acute or chronic diseases (e.g., inflammation, sepsis and cancer). New antibiotics against bacteria are rarely discovered in recent years, which necessitates the exploration of new antibacterial agents. Engineered nanomaterials (ENMs) have been extensively studied for antibacterial use because of their long lasting killing effects in wide spectra of bacteria. Graphene oxide (GO) is one of the most widely studied ENMs and exhibit strong bactericidal effects. The physicochemical properties of GO play important roles in bacterial killing by triggering a cascade of toxic events. Many studies have explored the signaling pathways of GO in bacteria. Although molecular initiating events (MIEs) of GO in bacteria dominate its killing efficiency as well as toxicity mechanisms, they have been rarely reviewed. In this report, we discussed the structure-activity relationships (SARs) involved in GO-induced bacterial killing and the MIEs including redox reaction with biomolecules, mechanical destruction of membranes and catalysis of extracellular metabolites. Furthermore, we summarized the clinical or commercial applications of GO-based antibacterial products and discussed their biosafety in mammal. Finally, we reviewed the remaining challenges in GO for antibacterial applications, which may offer new insights for the development of nano antibacterial studies.

Effects of stray lights on Faraday rotation measurement for polarimeter-interferometer system on EAST

A double-pass radially view 11 chords polarimeter-interferometer system has been operated on the experimental advanced superconducting tokamak and provides important current profile information for plasma control. Stray light originating from spurious reflections along the optical path (unwanted reflections from various optical components/mounts and transmissive optical elements such as windows, waveplates, and lens as well as the detectors) and also direct feedback from the retro-reflector used to realize the double-pass configuration can both contribute to contamination of the Faraday rotation measurement accuracy. Modulation of the Faraday rotation signal due to the interference from multiple reflections is observable when the interferometer phase (plasma density) varies with time. Direct reflection from the detector itself can be suppressed by employing an optical isolator consisting of a λ/4-waveplate and polarizer positioned in front of the mixer. A Faraday angle oscillation during the density ramping up (or down) can be reduced from 5°-10° to 1°-2° by eliminating reflections from the detector. Residual modulation arising from misalignment and stray light from other sources must be minimized to achieve accurate measurements of Faraday rotation.

Correlation of quantitative parameters of magnetic resonance perfusion-weighted imaging with vascular endothelial growth factor, microvessel density and hypoxia-inducible factor-1α in nasopharyngeal carcinoma: Evaluation on radiosensitivity study

OBJECTIVES

To investigate the correlation of parameters of magnetic resonance perfusion-weighted imaging (MR-PWI) with the expression of vascular endothelial growth factor (VEGF), hypoxia-inducible factor-1α (HIF-1α) and microvessel density (MVD) in nasopharyngeal carcinoma (NPC) so as to explore the value of predicting radiosensitivity.

DESIGN

A prospective study.

SETTING

Department of Head-and-neck radiotherapy in Hunan Cancer Hospital.

PARTICIPANTS

Ninety-four patients of NPC were included between December 2013 and December 2014.

MAIN OUTCOME MEASURES

The expression of VEGF, MVD and HIF-1α was studied by immunohistochemistry, and magnetic resonance perfusion-weighted imaging (MR-PWI) was performed before and after undergoing radiotherapy (20 Gy dose). Parameters of MR-PWI, volume of primary tumour and rate of tumour remission were measured and calculated. Patients with primary local tumour were then divided into completely response group (CR group) and partially response group (non-CR group) according to tumour regression condition. Relevant parameters were analysed by Spearman, and diagnostic efficiency of radiosensitivity was analysed by receiver operating characteristic curve (ROC).

RESULTS

The expression of VEGF was positively correlated with MVD (r = .322,P < .05), but the expression of HIF-1α was no significant correlations with VEGF and MVD. The expression VEGF was in positive correlation with fractional plasma volume (fpv) (r = .339, P = .05) before radiotherapy. There was a significant difference in the quantitative parameters of MR-PWI between CR group and non-CR group during the course of radiotherapy and at the end of radiotherapy treatment. The change of blood reflux constant (Δkep20) and extravascular extracellular space volume fraction (ΔVe20) before and after treatment was positively correlated with primary local tumour remission condition after 3 month treatment; Δkep and ΔVe were negatively correlated with primary local tumour remission condition after 3 months. Tumour regression rate was only positively correlated with Ve and the average volume of primary tumour after 2 week treatment (V1). ROC curve showed that R20 ≥ 65.69%, and was considered as a threshold to predict primary local tumour remission, with a sensitivity of 0.84 and specificity of 0.69, and area under the curve was 0.819 (P = .000).

CONCLUSIONS

The parameters of MR-PWI with the expression of VEGF, HIF-1α and MVD could be guidance for predicting radiosensitivity in NPC.

Nine Novel PAX9 Mutations and a Distinct Tooth Agenesis Genotype-Phenotype

Tooth agenesis is one of the most common developmental anomalies affecting function and esthetics. The paired-domain transcription factor, Pax9, is critical for patterning and morphogenesis of tooth and taste buds. Mutations of PAX9 have been identified in patients with tooth agenesis. Despite significant progress in the genetics of tooth agenesis, many gaps in knowledge exist in refining the genotype-phenotype correlation between PAX9 and tooth agenesis. In the present study, we complete genetic and phenotypic characterization of multiplex Chinese families with nonsyndromic (NS) tooth agenesis. Direct sequencing of polymerase chain reaction products revealed 9 novel (c.140G>C, c.167T>A, c.332G>C, c.194C>A, c.271A>T, c.146delC, c.185_189dup, c.256_262dup, and c.592delG) and 2 known heterozygous mutations in the PAX9 gene among 120 probands. Subsequently, pedigrees were extended, and we confirmed that the mutations co-segregated with the tooth agenesis phenotype (with exception of families in which DNA analysis was not available). In 1 family ( n = 6), 2 individuals harbored both the PAX9 c.592delG mutation and a heterozygous missense mutation (c.739C>T) in the MSX1 gene. Clinical characterization of families segregating a PAX9 mutation reveal that all affected individuals were missing the mandibular second molar and their maxillary central incisors are most susceptible to microdontia. A significant reduction of bitter taste perception was documented in individuals harboring PAX9 mutations ( n = 3). Functional studies revealed that PAX9 haploinsufficiency or a loss of function of the PAX9 protein underlies tooth agenesis.