Structural Design and Preliminary Tests of a Novel Patient Transfer Apparatus for Medical Scenarios

Patient transfer has always been a difficult problem, usually requiring multiple caregivers to work together, which is time consuming and can easily cause secondary injuries to the patient. In addition, with the crisis of COVID-19, the issue of patient transfer is even more critical, as caregivers are at a high risk of infection, causing significant damage to healthcare resources. In this paper, a patient transfer assist system named E-pat-plus (Easy Patient Transfer plus) has been proposed; it can assist caregivers in transferring patients, reduce direct contact between them, and avoid secondary injuries. In the mechanical structure of this apparatus, a novel five-gear assembly module and a synchronous belt pulley set are proposed; they are the key points to the basic functional realization of the device and can reduce the cost of the prototype. Furthermore, a fuzzy (proportion-integration-differentiation) PID-based cross-coupling control strategy is applied to the apparatus to ensure the stability and safety of the operation. Finally, some preliminary experiments, including current experiments and error experiments, are carried out to verify the reliability of the device and lay the foundation for clinical tests.

A bio-syringe mechanism and the pattern of genital correspondence in the weevil genus Sitona (Coleoptera: Curculionidae): an approach to the great interest of Sharp and Muir

The remarkable diversity in male and female genital morphology among the species of Sitona Germar might contribute to the understanding of the structural “lock-and-key” isolating mechanism. Recently, it has been found that in spite of the phallic sizes in male weevils of the genus Sitona, their internal sacs should precisely match with the vaginal infoldings of conspecific females. The present research also deals with the male transfer apparatus, which is a special organ for insemination procedure inside the female bursa copulatrix. A wedge-shaped structure with a fused ejaculatory pump was distinguished as the bio-syringe part of the transfer apparatus in the examined species. Two paired sclerites of the transfer apparatus support the bio-syringe, so that it would slide freely between them and lock precisely over the opening of the spermathecal duct inside the bursa copulatrix of the female. In this phenomenon, several new structures were also found, including a bursal sclerite (“bursal disc”) and a pair of miniature pouches (“bursal plugs”) which are embedded in the thickened wall of the female bursal lumen. These findings explain how the shapes of male and female copulatory organs are normally species-specific and provide an opportunity for understanding the role of the structural lock-and-key isolating mechanism.

Mobilization of IMEs Integrated in the oriT of ICEs Involves Their Own Relaxase Belonging to the Rep-Trans Family of Proteins

Integrative mobilizable elements (IMEs) are widespread but very poorly studied integrated elements that can excise and hijack the transfer apparatus of co-resident conjugative elements to promote their own spreading. Sixty-four putative IMEs, harboring closely related mobilization and recombination modules, were found in 14 Streptococcus species and in Staphylococcus aureus. Fifty-three are integrated into the origin of transfer (oriT) of a host integrative conjugative element (ICE), encoding a MobT relaxase and belonging to three distant families: ICESt3, Tn916, and ICE6013. The others are integrated into an unrelated IME or in chromosomal sites. After labeling by an antibiotic resistance gene, the conjugative transfer of one of these IMEs (named IME_oriTs) and its host ICE was measured. Although the IME is integrated in an ICE, it does not transfer as a part of the host ICE (no cis-mobilization). The IME excises and transfers separately from the ICE (without impacting its transfer rate) using its own relaxase, distantly related to all known MobT relaxases, and integrates in the oriT of the ICE after transfer. Overall, IME_oriTs use MobT-encoding ICEs both as hosts and as helpers for conjugative transfer. As half of them carry lsa(C), they actively participate in the dissemination of lincosamide–streptogramin A–pleuromutilin resistance among Firmicutes.