RESUMEN
Porcine deltacoronavirus (PDCoV) is a novel coronavirus that causes diarrhea in pigs of various ages, especially in suckling piglets, and there are no effective measures to prevent and control PDCoV currently. In this study, two adjuvants Al(OH)3 and ODN2395 working through different mechanisms were used to prepare inactivated PDCoV vaccines, and the immune effects of PDCoV inactivated vaccines were assessed in mice. From the results, we found that both PDCoV/Al(OH)3 vaccine and PDCoV/2395 vaccine could induce IgG and neutralizing antibodies with high levels in mice. At the same time, cytokines of IFN-γ, IL-4 and chemokine ligand of CXCL13 in serum were significantly increased after immunization, and reached the highest levels in PDCoV/2395 vaccine group, which suggested that PDCoV/2395 could promote the production of both Th1 and Th2 polarized cytokines. In addition, histopathological observations showed that vaccination helped mice resist PDCoV infection. These results indicated that both the two inactivated vaccines have good immune effects. Moreover, the PDCoV/2395 vaccine worked better than the PDCoV/Al(OH)3 vaccine for PDCoV/2395 having the good ability to induce both humoral and cellular immunogenicity. The PDCoV/2395 inactivated vaccine developed in this study might be an effective tool for the prevention of PDCoV infection.
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COVID-19 , Enfermedades de los Porcinos , Animales , Citocinas , Deltacoronavirus , Ratones , Porcinos , Vacunas de Productos InactivadosRESUMEN
Antibodies produced in animals vaccinated using live attenuated vaccines against Brucella spp. are indistinguishable using current conventional serological tests from those produced in infected animals. One potential approach is to develop marker vaccines in which specific genes have been deleted from parental vaccine strains that show good immunogenicity and vaccine efficacy. Corresponding methods of detection for antibodies raised by the marker vaccine should also be developed. A specific fragment of the bp26 gene of Brucella melitensis M5-90 was cloned into vector pQE32 to construct the recombinant plasmid (pQE32-rΔbp26). It was used to transform Escherichia coli M15 (pREP4) host cells, which expressed the rΔbp26 protein. Subsequently, the recombinant protein was purified by immobilized metal affinity chromatography and size-exclusion chromatography. The results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the purified rΔbp26 protein was represented by only one band, with a molecular weight of 14 kDa, and it showed good antigenic specificity on western blot and enzyme-linked immunosorbent assay (ELISA). The purified rΔbp26 protein was intended to be used as an antigen to develop a novel ELISA to differentiate animals vaccinated with bp26 mutants of Brucella spp. from those infected naturally and those vaccinated with the parental vaccine strains.
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Brucella melitensis/metabolismo , Epítopos , Regulación Bacteriana de la Expresión Génica , Proteínas de la Membrana , Proteínas Recombinantes , Pruebas Serológicas/métodos , Animales , Vacuna contra la Brucelosis/genética , Brucella melitensis/genética , Brucelosis/diagnóstico , Brucelosis/inmunología , Brucelosis/veterinaria , Ensayo de Inmunoadsorción Enzimática , Epítopos/inmunología , Enfermedades de las Cabras/sangre , Enfermedades de las Cabras/diagnóstico , Enfermedades de las Cabras/inmunología , Cabras , Proteínas de la Membrana/inmunología , Proteínas de la Membrana/aislamiento & purificación , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/aislamiento & purificación , Ovinos , Enfermedades de las Ovejas/diagnóstico , Enfermedades de las Ovejas/inmunologíaRESUMEN
Secret image sharing (SIS) is an important research direction in information hiding and data security transmission. Since the generated shadow images (shares) are always noise-like, it is difficult to distinguish the fake share from the unauthorized participant before recovery. Even more serious is that an attacker with a fake share can easily collect shares of other honest participants. As a result, it is significant to verify the shares, before being taken out for recovery. Based on two mainstream methods of SIS, such as polynomial-based SIS and visual secret sharing(VSS), this paper proposed a novel compressed SIS with the ability of shadow image verification. Considering that the randomness of the sharing phase of polynomial-based SIS can be utilized, one out of shares of (2, 2)-threshold random-grid VSS is embedded into all shares of polynomial-based SIS by a XOR operation as the verification information, while the other binary share is private for verification. Before recovery, each participant must extract the binary share from the grayscale share to perform XOR operation with the private share, and the original binary image can be recovered only with the true share. The proposed scheme also has the characteristics of shadow image verification, pixel compression, loss tolerance and lossless recovery. Through experiments and comparative analysis of related research results, the effectiveness and advantages of the method are verified.
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In practice, most audio files such as MP3 and AAC are stored and transmitted in the form of compressed files, which can serve as the cover in audio steganography. Currently, the prevailing audio steganography methods are not ideal because of the drawbacks. Some are characterized by low capacity while others are irreversible. In this paper, we propose a method to embed secret messages in MP3 encoding. Our strategy is to hide the information by Huffman table transformation. We extract secret information by analyzing side information. Experimental results show that our method can greatly improve the steganographic capacity with low distortion and high security. Meanwhile, it featured with higher decoding rate and reversible over some state-of-the-art methods.
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Algoritmos , Seguridad Computacional , Compresión de Datos , Procesamiento de Imagen Asistido por Computador , Informática/métodos , Recursos Audiovisuales , Confidencialidad , Medidas de Seguridad , Procesamiento de Señales Asistido por Computador , Relación Señal-Ruido , Programas InformáticosRESUMEN
Secret image sharing (SIS) belongs to but differs from secret sharing. In general, conventional (k,n) threshold SIS has the shortcoming of "all-or-nothing". In this article, first we introduce ramp SIS definition. Then we propose a (k1,k2,n) ramp SIS based on the Chinese remainder theorem (CRT). In the proposed scheme, on the one hand, when we collect any k1 or more and less than k2 shadows, the secret image will be disclosed in a progressive way. On the other hand, when we collect any k2 or more shadows, the secret image will be disclosed losslessly. Furthermore, the disclosing method is only modular arithmetic, which can be used in some real-time applications. We give theoretical analyses and experiments to show the effectiveness of the proposed scheme.
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Venous thromboembolism (VTE), which is manifested as deep vein thrombosis (DVT) and pulmonary embolism (PE), represents a significant cause of death, disability, and discomfort. They are frequent complications of various surgical procedures. The aging population and the survival of more severely injured patients may suggest an increasing risk of thromboembolism in the trauma patients. Expanded understanding of the population at risk challenges physicians to carefully examine risk factors for VTE to identify high-risk patients who can benefit from prophylaxis. An accurate knowledge of evidence-based risk factors is important in predicting and preventing postoperative DVT, and can be incorporated into a decision support system for appropriate thromboprophylaxis use. Standard use of DVT prophylaxis in a high-risk trauma population leads to a low incidence of DVT. The incidence of VTE is common in Asia. The evaluation includes laboratory tests, Doppler test and phlebography. Screening Doppler sonography should be performed for surveillance on all critically injured patients to identify DVT. D-Dimer is a useful marker to monitor prophylaxis in trauma surgery patients. The optimal time to start prophylaxis is between 2 hours before and 10 hours after surgery, but the risk of PE continues for several weeks. Thromboprophylaxis includes graduated compression stockings and anticoagulants for prophylaxis. Anticoagulants include Warfarin, which belongs to Vitamin K antagonists, unfractionated heparin, low molecular weight heparins, factor Xa indirect inhibitor Fondaparinux, and the oral IIa inhibitor Melagatran and ximelagatran. Recombinant human soluble thrombomodulin is a new and highly effective antithrombotic agent. Prophylactic placement of vena caval filters in selected trauma patients may decrease the incidence of PE. The indications for prophylactic inferior vena cava filter insertion include prolonged immobilization with multiple injuries, closed head injury, pelvic fracture, spine fracture, multiple long bone fracture, and attending discretion. Multiple-trauma patients are at increased risk for DVT but are also at increased risk of bleeding, and the use of heparin may be contraindicated. Serial compression devices (SCDs) are an alternative for DVT prophylaxis. Compression devices provide adequate DVT prophylaxis with a low failure rate and no device-related complications. Immobilization is one of important reasons of VTE. The ambulant patient is far less likely to develop complications of inactivity, not only venous thrombosis, but also contractures, decubitus ulcers, or osteoporosis (with its associated fatigue fractures), as well as bowel or bladder complications.
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Anticoagulantes/uso terapéutico , Procedimientos Ortopédicos/efectos adversos , Embolia Pulmonar/prevención & control , Trombosis de la Vena/prevención & control , Inhibidores del Factor Xa , Heparina/uso terapéutico , Heparina de Bajo-Peso-Molecular/uso terapéutico , Humanos , Complicaciones Posoperatorias/epidemiología , Proteínas Recombinantes/uso terapéutico , Factores de Riesgo , Trombomodulina/uso terapéutico , Filtros de Vena Cava , Trombosis de la Vena/epidemiología , Vitamina K/antagonistas & inhibidores , Warfarina/uso terapéuticoRESUMEN
Prostate cancer presents high occurrence worldwide. Medicinal plants are a major source of novel and potentially therapeutic molecules; therefore, the aim of the present study was to investigate the possible anti-prostate cancer activity of afzelin, a flavonol glycoside that was previously isolated from Nymphaea odorata. The effect of afzelin on the proliferation of androgen-sensitive LNCaP and androgen-independent PC-3 cells was evaluated by performing a water soluble tetrazolium salt-1 assay. In addition, the effect of afzelin on the cell cycle of the LNCaP and PC-3 prostate cancer cell lines was evaluated. Western blot analysis was performed to evaluate the effect of afzelin on the kinases responsible for the regulation of actin organization. Afzelin was identified to inhibit the proliferation of LNCaP and PC3 cells, and block the cell cycle in the G0 phase. The anticancer activity of afzelin in these cells was determined to be due to inhibition of LIM domain kinase 1 expression. Thus, the in vitro efficacy of afzelin against prostate cancer is promising; however, additional studies on different animal models are required to substantiate its anticancer potential.
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The temperature variation, setting time, phase compositions and compressive strength of magnesium phosphate chemically bonded ceramics were important for its application in biomedical field. Different amounts of liquid were added into the premixed acid phosphate and oxide powders in order to study the effect of liquid-to-solid ratios on the properties of magnesium phosphate chemically bonded ceramics. The results indicated that the setting time increased and the maximum temperature decreased as the liquid-to-solid ratio increases. The hydrated product was mainly composed of magnesium potassium phosphate hexahydrate, which was not affected by the liquid-to-solid ratios. Besides, magnesia was also found because it was an obvious excess of the hydrated reaction. The compressive strength decreased as the liquid-to-solid ratios increase possibly because of the higher porosity caused by the superfluous liquid. According to the performed study, results indicated that the properties of MPCBC could be adjusted by changing the liquid-to-solid ratios.
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Cerámica , Compuestos de Magnesio/química , Fosfatos/química , Ensayo de Materiales , TemperaturaRESUMEN
The compressive strength of magnesium potassium phosphate chemically bonded ceramics is important in biomedical field. In this work, the compressive strength of magnesium potassium phosphate chemically bonded ceramics was investigated with different liquid-to-solid and MgO-to-KH2PO4 ratios. X-ray diffractometer was applied to characterize its phase composition. The microstructure was imaged using a scanning electron microscope. The results showed that the compressive strength of the chemically bonded ceramics increased with the decrease of liquid-to-solid ratio due to the change of the packing density and the crystallinity of hydrated product. However, with the increase of MgO-to-KH2PO4 weight ratio, its compressive strength increased firstly and then decreased. The low compressive strength in lower MgO-to-KH2PO4 ratio might be explained by the existence of the weak phase KH2PO4. However, the low value of compressive strength with the higher MgO-to-KH2PO4 ratio might be caused by lack of the joined phase in the hydrated product. Besides, it has been found that the microstructures were different in these two cases by the scanning electron microscope. Colloidal structure appeared for the samples with lower liquid-to-solid and higher MgO-to-KH2PO4 ratios possibly because of the existence of amorphous hydrated products. The optimization of both liquid-to-solid and MgO-to-KH2PO4 ratios was important to improve the compressive strength of magnesium potassium phosphate chemically bonded ceramics.