The Absence of Abdominal Pigmentation in Livestock Associated Culicoides following Artificial Blood Feeding and the Epidemiological Implication for Arbovirus Surveillance

Culicoides midges (Diptera: Ceratopogonidae), the vectors of economically important arboviruses such as bluetongue virus and African horse sickness virus, are of global importance. In the absence of transovarial transmission, the parity rate of a Culicoides population provides imperative information regarding the risk of virus dispersal. Abdominal pigmentation, which develops after blood feeding and ovipositioning, is used as an indicator of parity in Culicoides. During oral susceptibility trials over the last three decades, a persistent proportion of blood engorged females did not develop pigment after incubation. The present study, combining a number of feeding trials and different artificial feeding methods, reports on this phenomenon, as observed in various South African and Italian Culicoides species and populations. The absence of pigmentation in artificial blood-fed females was found in at least 23 Culicoides species, including important vectors such as C. imicola, C. bolitinos, C. obsoletus, and C. scoticus. Viruses were repeatedly detected in these unpigmented females after incubation. Blood meal size seems to play a role and this phenomenon could be present in the field and requires consideration, especially regarding the detection of virus in apparent “nulliparous” females and the identification of overwintering mechanisms and seasonally free vector zones.

Development and study on mechanical properties of small diameter artificial blood vessel by using electrospinning and 3d printing

The small diameter artificial blood vessel is synthesized with a diameter less than or equal to 6 millimetres. This technique has been used in coronary artery bypass grafting to treat coronary artery disease. Currently, the problem of coronary artery disease is still common, in addition to aortic aneurysm caused by the incompatibility of mechanical properties between the artificial blood vessel and the local blood vessel in the patient’s body. This research aims to solve the aforementioned problems using electrospinning and 3D printing technologies, as many types of materials are supported, all parameters are easy to change, and the cost is low. In this report, we describe a design for a small diameter polylactic acid (PLA) vascular graft fabricated by electrospinning with solutions of PLA in AC/DMF (1:1) 10, 12 and 15% w/v at 4 mm. The electrospun PLA nanofibers are tested for their morphology, contact angle, and seam strength. As the results, the fibres are still no same direction alignment due to insufficient rotation speed. The filament holding force is in the range of 1.90-2.71 N and the contact angles are greater than 90° because the samples are not wettable and have hydrophobic property. Further on, we will investigate other required properties, such as cell culture and other mechanical properties. Furthermore, we will compare the results with 3D printed artificial blood vessels with small diameter.

Preparation of Electrospun Polyvinyl Alcohol/Nanocellulose Composite Film and Evaluation of Its Biomedical Performance

Using polyvinyl alcohol (PVA) and nanocellulose (NC) as raw materials, PVA/NC nanofiber membranes were prepared by electrospinning. The hydrogen bonding, crystalline properties and microscopic appearance of PVA/NC membranes with different NC contents were characterized. The mechanical properties, liquid absorption and cytotoxicity of the nanofiber membrane were evaluated. The results show that the free hydroxyl group of the PVA/NC nanofiber membranes have a maximum value of 9% at a mass fraction of 6% NC. The crystallinity of the PVA/NC nanofiber membranes and the average diameter of the nanofibers decreased and then increased as the NC content increased, with a minimum value of 38.23% and 272.03 nm, respectively, at 6% NC content. At this time, the contact angle was the smallest. The maximum strength of the PVA/NC nanofiber membranes is 75.8% higher than that of the PVA membrane at 2% NC content. With increasing NC content, the absorption of water, PBS sustained-release suspensions and artificial blood by PVA/NC nanofiber membranes increases. Cytotoxicity tests have shown that PVA/NC nanofiber membranes are non-toxic, have good cytocompatibility and are expected to be used in the field of medical dressings.

ARTIFICIAL BLOOD: AN ACCOUNT OF HBOC AND PFC APPROACHES

In the field of medicine, artificial blood is an innovative concept, where specially designed compounds are developed to perform the task of transport and delivery of oxygen. Hence, it can potentially replace the function of allogenic human blood transfusion. Several molecules have been developed using several approaches. However, with continuous refinements in the past few decades, the ideal blood substitute would likely be Hemoglobin Based Oxygen Carrier. The benefits of HBOCs are tremendous, as they do not require compatibility testing or tissue matching, are non-pathogenic, have a long shelf life, and can even be stored at room temperature. The advent of artificial blood is projected to have a remarkable impact on medical care in the future. While it will complement blood transfusion safely, it will also create a stable supply of effective products. It is likely to reduce the requirements of blood transfusions drastically in settings of surgery, trauma, or warfare.