海产品加工副产物中磷脂的研究进展

我国海洋生物资源丰富,海产品加工业发展较快,鱼、虾、贝类等加工过程中产生大量的副产物,造成资源的严重浪费以及环境的污染。许多海产品加工副产物中含有丰富的磷脂,海洋磷脂由于含有丰富的二十二碳六烯酸(DHA)和二十碳五烯酸(EPA)等多不饱和脂肪酸侧链而具有极高的营养价值,将这些磷脂成分进行高值化利用对减少资源浪费、降低企业成本、增加企业经济效益、改善生态环境等均具有非常重要的意义。综述了海产品加工副产物来源磷脂的提取制备、成分分析及生物活性等方面的研究进展,以期为海产品进一步的综合利用和精深加工提供一定的理论参考。

The journey of multifunctional bone scaffolds fabricated from traditional toward modern techniques

As a bone scaffold,meeting all basic requirements besides dealing with other bone-related issues-bone cancer and accelerated regeneration-is not expected from traditional scaffolds,but a newer class of scaffolds called multifunctional.From a clinical point of view,being a multifunctional scaffold means reducing in healing time,direct costs-medicine,surgery,and hospitalization-and indirect costs-loss of mobility,losing job,and pain.The main aim of the present review is following the multifunctional bone scaffolds trend to deal with both bone regeneration and cancer therapy.Special consideration is given to different fabrication techniques which have been applied to yield these materials spanning from traditional to modern ones.Moreover,the hierarchical structure of bone plus bone cancers and available medicines to them are introduced to familiarize the potential reader of review with the pluri-disciplinary essence of the field.Eventually,a brief discussion relating to the future trend of these materials is provided.

A simple method for inducing nonalcoholic steatohepatitis with fibrosis

Background: Nonalcoholic fatty liver disease(NAFLD) is increasingly occurring in sedentary people, and may progress to NASH and hepatocellular carcinoma. It is essential to design affordable animal models for the study of various diseases, including fatty liver, which was the aim of the study. In this study, a high-fat diet was devised that triggers NASH’s animal model quickly and easily. High-fat diet(HFD) was used both with intra-mouth oral gavage and in combination with animal pellets.Methods: Twenty-four male C57 BL/6 J mice were divided into HFD and ND groups, which received a high-fat diet and a normal diet, respectively. At the end of the experiment(fourth week of treatment), body and liver weights, biochemical parameters, PPAR-α gene expression and histopathologic characteristics of the liver were evaluated.Results: During 4 weeks, body weight of mice did not show a significant increase in the HFD group compared to the ND group, while weight gain of the liver was significant. Histological assessment of the HFD group’s liver confirmed NASH symptoms. In the HFD group, HDL-c, SOD, catalase, FRAP, adiponectin, and PPAR-α decreased significantly, and lipid profiles, hepatic enzymes, MDA, leptin, and TNF-α showed a significant increase compared to the ND group.Conclusion: Our high-fat diet has successfully induced all aspects of NASH with fibrosis in 4 weeks, and with low cost.

Gracilaria fisheri oligosaccharides ameliorate inflammation and colonic epithelial barrier dysfunction in mice with acetic acid-induced colitis

Objective:To investigate the effect of Gracilaria fisheri oligosaccharides(GFO)on inflammation and colonic epithelial barrier dysfunction in colitis mice.Methods:The animals were treated by oral gavage with distilled water,1000 mg/kg inulin,100,500,or 1000 mg/kg GFO for 14 d,or treated with 50 mg/kg mesalamine for 5 d after colitis induction(on day 10).Histopathology,inflammatory cytokines,colonic permeability,and tight junction proteins were investigated by hematoxylin and eosin staining,immunohistochemical staining,Ussing chamber technique,and Western blotting assays,respectively.Results:GFO ameliorated histological damage in colitis mice when compared to untreated colitis mice.Treatments with 100,500,and 1000 mg/kg GFO reduced TNF-αexpression,while IL-1βwas significantly reduced in colitis mice treated with 500 and 1000 mg/kg.Compared to untreated colitis mice,GFO increased transepithelial electrical resistance,reduced fluorescein isothiocyanate-dextran paracellular flux,and modulated tight junction proteins(occludin and claudin 2)in colitis mice.Conclusions:GFO has anti-inflammatory activity and could modulate colonic epithelial barrier dysfunction in acetic acid-induced colitis mice.Furthermore,GFO could modulate the expression of tight junction proteins that play important roles in colonic barrier function.

Coagulase gene polymorphism of Staphylococcus aureus isolates: A study on dairy food products and other foods in Tehran, Iran

Coagulase is considered as a major determinant factor for the identification of Staphylococcus aureus strains.The 3-end coding region of the coagulase(coa)gene contains a series of 81-bp tandem repeats,which differ in the number and location of enzymatic restriction sites among different isolates.coa PCR-RFLP has been used widely to type S.aureus isolates in epidemiological studies.The current study was conducted to investigate the coagulase gene polymorphisms in S.aureus isolated from various food samples using an in house PCR-RFLP method.A total of 100 strains of S.aureus were isolated from food samples.Isolates were typed by PCR-RFLP analysis using NdeI restriction digestion of the coagulase gene PCR products.Results showed that amplification of coagulase genes from S.aureus produced different PCR products.The isolates were grouped into 18 genotypes using RFLP analysis results of the genes.In this study,the S.aureus isolates have been shown to include more than one coagulase genotype,but only had a few coa genotypes predominated.

Production of a polyclonal antibody to the VP26 nucleocapsid protein of white spot syndrome virus （wssv） and its use as a biosensor

White spot syndrome virus （WSSV） is a major cause of high mortality in cultured shrimp all over the world. VP26 is one of the structural proteins of WSSV that is assumed to assist in recognizing its host and assists the viral nucleocapsid to move toward the nucleus of the host cell. The objective of this work was to produce a polyclonal antibody against VP26 and use it as a biosensor. The recombinant VP26 protein （rVP26） was produced in E. coli （BL21）, purified and used for immunizing rabbits to obtain a polyclonal antibody. Western blot analysis confirmed that the antiserum had a specific immunoreac- tivity to the VP26 of WSSV. This VP26 antiserum was immobilized onto a gold electrode for use as the sensing surface to detect WSSV under a flow injection system. The impedance change in the presence of VP26 was monitored in real time. The sensitivity linear range of 160 160000 of the biosensor was in the copies of WSSV, indicating that it is good and sensitive for analysis of WSSV. The specificity of the biosensor was supported by the observation that no impedance change was detected even at high concentrations when using Yellow Head Virus （YHV）. This biosensor may be applied to monitor the amount of WSSV in water during shrimp cultivation.

Particle agglomeration and interphase interactions affect Young’s modulus of nanobiocomposites:eyes at mathematical modeling

Computational modeling is a new approach to optimize Young’s modulus of scaffolds by performing a minimal number of experiments.However,presenting a modeling algorithm to predict Young’s modulus and characterize the governing parameters is a challenging task.Here,a novel modeling approach has been proposed to estimate Young’s modulus of scaffolds,considering particle agglomeration and interphase interactions.Employing the characteristic parameters of these two phenomena,we modified the Maxwell model using a simple three-step algorithm to determine the optimal value of these parameters and predict Young’s modulus.Interestingly,the model provides a precision of more than 95%for all the studied cases and presents a remarkably better performance compared to the two other models.For instance,the proposed model has reduced the average absolute relative error of Young’s modulus of poly(3-hydroxybutyrate)-keratin/hydroxyapatite nanorods from 25.1%to 0.08%,demonstrating the high efficiency of this model in predicting Young’s modulus of scaffolds.The results of this study could lighten the way of fabricating nanobiocomposites with optimal mechanical properties,spending lower cost and energy.

Proteomics techniques in protein biomarker discovery

Protein biomarkers represent specific biological activities and processes, so they have had a critical role in cancer diagnosis and medical care for more than 50 years. With the recent improvement in proteomics technologies, thousands of protein biomarker candidates have been developed for diverse disease states. Studies have used different types of samples for proteomics diagnosis. Samples were pretreated with appropriate techniques to increase the selectivity and sensitivity of the downstream analysis and purified to remove the contaminants. The purified samples were analyzed by several principal proteomics techniques to identify the specific protein. In this study, recent improvements in protein biomarker discovery, verification, and validation are investigated. Furthermore, the advantages, and disadvantages of conventional techniques, are discussed. Studies have used mass spectroscopy (MS) as a critical technique in the identification and quantification of candidate biomarkers. Nevertheless, after protein biomarker discovery, verification and validation have been required to reduce the false-positive rate where there have been higher number of samples. Multiple reaction monitoring (MRM), parallel reaction monitoring (PRM), and selected reaction monitoring (SRM), in combination with stable isotope-labeled internal standards, have been examined as options for biomarker verification, and enzyme-linked immunosorbent assay (ELISA) for validation.

Electrospun Aloe Vera Extract Loaded Polycaprolactone Scaffold for Biomedical Applications:A Promising Candidate for Corneal Stromal Regeneration

Corneal diseases,the second leading cause of global vision loss affecting over 10.5 million people,underscores the unmet demand for corneal tissue replacements.Given the scarcity of fresh donor corneas and the associated risks of immune rejection,corneal tissue engineering becomes imperative.Developing nanofibrous scaffolds that mimic the natural corneal structure is crucial for creating transparent and mechanically robust corneal equivalents in tissue engineering.Herein,Aloe Vera Extract(AVE)/Polycaprolactone(PCL)nanofibrous scaffolds were primed using electrospinning.The electrospun AVE/PCL fibers exhibit a smooth,bead-free morphology with a mean diameter of approximately 340±95 nm and appropriate light transparency.Mechanical measurements reveal Young’s modulus and ultimate tensile strength values of around 3.34 MPa and 4.58 MPa,respectively,within the range of stromal tissue.In addition,cell viability of AVE/PCL fibers was measured against Human Stromal Keratocyte Cells(HSKCs),and improved cell viability was observed.The cell-fiber interactions were investigated using scanning electron microscopy.In conclusion,the incorporation of Aloe Vera Extract enhances the mechanical,optical,hydrophilic,and biological properties of PCL fibers,positioning PCL/AVE fiber scaffolds as promising candidates for corneal stromal regeneration.

Fabrication of Porous Mg-Zn Scaffold through Modified Replica Method for Bone Tissue Engineering

Biodegradable scaffolds are essential parts in hard tissue engineering. A highly porous magnesium-zinc （Mg-Zn 4 wt.%） scaffold with different Mg-Zn powder to liquid media ratios （50 wt.%, 70 wt.% and 90 wt.%） and different concentrations of ethanol （0 vol.%, 10 vol.%, 20 vol.% and 40 vol.%） were prepared through modified replica method. The mechanical properties were assessed through compression test and the structures of scaffolds were examined by Scanning Electron Microscope （SEM）. Results show that, the increase in Mg-Zn powder to liquid media ratio （50 wt.% to 90 wt.%） in ethanol free slurry, increases the thickness of struts （37 lam to 74 lam） and the plateau stress （0.5 MPa to 1.4 MPa）. The results obtained from X-ray Diffractometry （XRD） and compression test indicate that consuming ethanol in liquid media of replica, results in higher plateau stress by 46% due to less Mg-water reaction and no formation of Mg（OH）2 in the scaffold. The results of porosity measurement indicate that water-ethanol mixture composition and different solid fractions have no significant effects on true and apparent porosities of the fabricated scaffolds.

Voltammetric determination of venlafaxine as an antidepressant drug employing Gd_2O_3 nanoparticles graphite screen printed electrode

Graphite screen printed electrode modified with Gd_2 O_3 nanoparticles(Gd_2 O_3/SPE) was developed for the determination of venlafaxine(VF). The Gd_2 O_3 nanoparticles were thoroughly characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM) and X-ray diffraction(XRD) analyses. To study the electrochemical behaviour of venlafaxine cyclic voltammetry(CV), chronoamperometry(CHA)and differential pulse voltammetry(DPV) were employed. These studies reveal that the oxidation of venlafaxine is facilitated at Gd_2 O_3/SPE. After optimization of analytical conditions, analysis of venlafaxine using the modified electrode in 0.1 mol/L PBS(pH 7.0) demonstrates that the peak currents corresponding to venlafaxine vary linearly with its concentration in the range of 5.0 ×10^(-6)-9.0 × 10^(-4) mol/L. The detection limit(S/N = 3) of 2.1 × 10^(-7) mol/L is obtained for venlafaxine using DPV. The prepared modified electrode benefits from advantages such as simple preparation method, high sensitivity and low detection limit.Moreover, the evaluation of practical applicability of this proposed method is successful in the identification of venlafaxine in pharmaceutical formulations, urine and water samples.

Application of graphite screen printed electrode modified with dysprosium tungstate nanoparticles in voltammetric determination of epinephrine in the presence of acetylcholine

The current work focuses on the development of a sensitive and selective electrochemical device based on a graphite screen printed electrode modified with Dy2（WO4）3 nanoparticles（DWO/SPE） for the analysis of epinephrine in samples also containing acetylcholine. The study proves that the sensor has excellent electron-mediating behavior in the oxidation of epinephrine in a 0.1 mol/L phosphate buffer solution（PBS）（pH 7.0）. The application of the DWO/SPE in differential pulse voltammetry（DPV） is found to lead to distinct response for the oxidation of epinephrine and acetylcholine, with the potentials of the epinephrine and acetylcholine peaks（△Ep） to be 550 mV apart. The detection limits of the method for epinephrine and acetylcholine are 0.5 and 0.7 μmol/L（S/N = 3） and the responses are found to be linear in the concentration ranges of 1.0-900.0 μmol/L and 1.0-1200.0 μmol/L in a PBS buffer（pH = 7.0）respectively. The modified electrode was used for the detection of epinephrine and acetylcholine in real samples and found to produce satisfactory results. These results can be a proof that Dy2（WO4）3 nanoparticles can find promising applications in electrochemical sensors to be used for the analysis of（bio）chemical species.