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With the development of Internet of Things and intelligence, cleaning mobile robots have gradually replaced the traditional manual cleaning work, and intelligence has become the main research direction of sweeping robots. As a new product in the field of service robot, mopping robot has made some achievements, but there are still many key technical problems to be solved or improved. In order to improve the safety of products in public places such as shopping malls, a robot with multiple cleaning functions such as vacuuming, mopping and drying is proposed. The mechanical mechanisms mainly include a frame, a three wheel walking mechanism, a sweeping mechanism, a mopping mechanism, a drying mechanism, etc. It can realize wifi control and mobile phone APP control, and solve the problems of the existing mopping robot such as single function, low cleaning efficiency, and the danger of slippery ground.

With the increasing application of PVC water supply pipe in production and life, this paper aims at the problem that there is no single sealing ring connected large diameter PVC pipe interface sealing detection equipment in the construction site of agricultural water supply. According to the sealing test method of negative pressure test, a set of large diameter PVC pipe interface sealing test device is designed, and the corresponding test procedures and standards are put forward. The field sealing test of large diameter PVC pipe interface is carried out, and the portable aviation aluminum box with universal wheel is designed and customized. The device has the advantages of simple structure, easy installation and disassembly, easy carrying, and is suitable for field operation. It provides important equipment support for the better promotion and use of large PVC pipes.

In the production process of baking food processing enterprises, cakes, biscuits and other products made by steaming are generally installed in the baking tray and baked in the oven. The temperature of the baking tray is above 100 degrees Celsius when leaving the oven. The high temperature environment is not conducive to the protection of workers. It needs to be left to cool and then be transported, so the production efficiency is low. In order to solve this problem, a method of replacing the manual handling of the baking tray and removing the baked cake product with a turning robot is proposed. At the same time, two methods for improving the design of the cake production line are given, and the structure and use of the two products of the single-column turning manipulator and the articulated turning manipulator are introduced. The single-column turning manipulator consists of a base, a single-column rotating mechanism, a lifting mechanism, a swing arm, a pneumatic gripping mechanism, etc. A frame-type pneumatic gripping mechanism is adopted, and driven by the turning motor, and can realize the turning of the baking tray. The articulated turning manipulator consists of a base, a waist, a big arm, a small arm, a wrist, and a hand actuator. The hand adopts a rotatable square shaft end structure with an electromagnetic device, transforming the cake baking tray to increase the square groove meshed with it, so as to realize the flipping action of the cake baking tray.

The glass curtain wall has good heat preservation and moisture-proof performance and beautiful appearance. It is used as exterior wall decoration in high-rise buildings, its cleaning work is difficult and dangerous. In this paper, the design research of the glass curtain wall cleaning robot is carried out, and a rail-type glass curtain wall cleaning robot is designed, which is mainly composed of a detachable rail and a robot, and is controlled by a 51 microcomputer. The three-dimensional design of the cleaning robot was performed using NX software, and a model prototype was produced. This robot is light in weight and flexible in control. It is suitable for cleaning operations of large glass curtain walls and can reduce the risk factor and labor intensity of cleaning operations.

The booming information technology has brought non-negligible and irreversible great influence on our production and life styles, including the education sector. At present, although the teaching mode of culture pedagogy guarantees students’ overall grasp of culture pedagogy, students’ learning for culture pedagogy is not deep enough, and they can neither internalize relevant knowledge nor form the cure quality of culture pedagogy. Besides, the teaching effect is not entirely satisfactory. Thus, the teaching mode which is based on CASH curriculum idea and supported by information technology combines network learning space and utilizes the patent A Method to Achieve Auxiliary Operation in PPT Courseware Playing Process, and the classroom teaching quality evaluation method based on distance comparison were proposed in this study. In addition, the modeling process of network learning space was introduced. The patent A Method to Achieve Auxiliary Operation in PPT Courseware Playing Process, standardized method of distance grade evaluation model, modeling and computer operating system, and teaching case design process of CASH curriculum idea were applied. It was found through the experiment that, students are satisfied with the teaching mode of network learning space based on CASH curriculum idea, and consider that it plays a great role in the learning process, and both the teaching efficiency and teaching quality improve obviously.

A seven-degrees-of-freedom (DOF) dynamic model was established based on the Lagrange equation to analyse the lateral stability and instability mechanism of an articulated wheel loader. A scale wheel loader was designed and manufactured to validate the dynamic model in two conditions, namely turning on slopes and passing over obstacles. Experimental data and simulated data fitted well on the whole, so the developed dynamic model was proved to be useful and could serve as an important tool to analyse the stability of wheel loaders. At last, the lateral stability of one ZL50 wheel loader was analysed by using this dynamic model. The results showed that there is a phenomenon of sudden stability losing during the wheel loader cornering due to the relative rotation between the subframe and the rear axle. The subframe can enhance the stability when the wheel loader is passing over obstacles but reduces the stability when it is turning.

Background After the earthquake on 14, April 2010 at Yushu in China, a plague epidemic hosted by Himalayan marmot (Marmota himalayana) became a major public health concern during the reconstruction period. A rapid assessment of the distribution of Himalayan marmot in the area was urgent. The aims of this study were to analyze the relationship between environmental factors and the distribution of burrow systems of the marmot and to predict the distribution of marmots. Methods Two types of marmot burrows (hibernation and temporary) in Yushu County were investigated from June to September in 2011. The location of every burrow was recorded with a global positioning system receiver. An ecological niche model was used to determine the relationship between the burrow occurrence data and environmental variables, such as land surface temperature (LST) in winter and summer, normalized difference vegetation index (NDVI) in winter and summer, elevation, and soil type. The predictive accuracies of the models were assessed by the area under the curve of the receiving operator curve. Results The models for hibernation and temporary burrows both performed well. The contribution orders of the variables were LST in winter and soil type, NDVI in winter and elevation for the hibernation burrow model, and LST in summer, NDVI in summer, soil type and elevation in the temporary burrow model. There were non-linear relationships between the probability of burrow presence and LST, NDVI and elevation. LST of 14 and 23 °C, NDVI of 0.22 and 0.60, and 4100 m were inflection points. A substantially higher probability of burrow presence was observed in swamp soil and dark felty soil than in other soil types. The potential area for hibernation burrows was 5696 km2 (37.7 % of Yushu County), and the area for temporary burrows was 7711 km2 (51.0 % of Yushu County). Conclusions The results suggested that marmots preferred warm areas with relatively low altitudes and good vegetation conditions in Yushu County. Based on these results, the present research is useful in understanding the niche selection and distribution pattern of marmots in this region.

Artificially passive immunization has been demonstrated to be effective againstYersinia pestisinfection in animals. However, maternal antibodies' protective efficacy against plague has not yet been demonstrated. Here, we evaluated the kinetics, protective efficacy, and transmission modes of maternal antibodies, using mice immunized with plague subunit vaccine SV1 (20 μg of F1 and 10 μg of rV270). The results showed that the rV270- and F1-specific antibodies could be detected in the sera of newborn mice (NM) until 10 and 14 weeks of age, respectively. There was no antibody titer difference between the parturient mice immunized with SV1 (PM-S) and the caesarean-section newborns (CSN) from the PM-S or between the lactating mice immunized by SV1 (LM-S) and the cross-fostered mice (CFM) during 3 weeks of lactation. The NM had a 72% protection against 4,800 CFUY. pestisstrain 141 challenge at 6 weeks of age, whereas at 14 weeks of age, NM all succumbed to 5,700 CFU ofY. pestischallenge. After 7 weeks of age, CFM had an 84% protection against 5,000 CFU ofY. pestischallenge. These results indicated that maternal antibodies induced by the plague subunit vaccine in mother mice can be transferred to NM by both placenta and lactation. Passive antibodies from the immunized mothers could persist for 3 months and provide early protection for NM. The degree of early protection is dependent on levels of the passively acquired antibody. The results indicate that passive immunization should be an effective countermeasure against plague during its epidemics.

Background. Primarypneumonicplague(PPP)causedbyYersiniapestisisthemostthreateningclinicalformofplague. An outbreak was reported in July 2009 in Qinghai Province, China.Methods. This outbreak was investigated by clinical, epidemiological, bacteriological, and immunologicalmethods. Multilocus variablenumber tandem repeat analysis (MLVA) was used to track the source of the outbreak.Results. The index case, a patient with PPP, contaminated 11 close contacts. All the 12 cases, including theindexpatient, experiencedsuddenonsetof fever, headache,and productivecoughingwithbloody sputum.Threeofthem died. Nevertheless, another 61 direct and 256 indirect contacts were not infected during the 2-weekquarantine. Antibodies to F1 antigen were detected in 9 survival cases, with a 4-fold increase in titers in serumsamples collected at different periods. Seven strains of Y. pestis were isolated from dogs and patients. Fieldinvestigation and MLVA of the isolated strains revealed that this outbreak was started by a deceased dog.Conclusion. Dogs are believed to be an indicator animal for plague surveillance, but their association with PPPis rare. Our results provide evidence for this possibility, which suggests the public health significance of dogs asa source of plague.Plague, caused by Yersinia pestis, was classified asa reemerging infectious disease by the World HealthOrganization (WHO) in the early 1980s, because thereported cases around the world were increasing atthat time. There are different forms of plague, in-cluding bubonic and pneumonic, and the latter is themost threatening clinical form. Primary and second-arypneumonicplagueshavebeenwell-documentedinhistory.Theprimarypneumonicplague(PPP)out-breaks in Oakland in 1919, Los Angeles in 1924 [1],Manchuria during 1910–1911 [2], and Madagascar in1957 are the most frequently cited ones. PPP was alsoreported recently in the United States, India, Uganda,Zambia, Ecuador, and Madagascar [3–11]. BecausePPP progresses so rapidly that the patients often re-ceived a diasgnosis or were suspected to have plagueonly in the late stage of the disease, most of the PPPcases were reported on the basis of retrospectiveepidemiological investigations with only some ofthem confirmed by bacterial isolation and antibodydetection.On29July2009,asuspectedPPPoutbreakinXinghaiCounty, Qinghai provinceof China,was reportedtotheQinghai Ministry of Health by China’s public healthemergency reporting system. The next day, a group ofplague experts, including epidemiologists, bacteriolo-gists, doctors, and management officers, were sentout for further investigation in the Xinghai CountyTibetan (XCT) hospital, where the suspected patientshad been admitted.

In our previous study, complete protection was observed in Chinese-origin rhesus macaques immunized with SV1 (20 µg F1 and 10 µg rV270) and SV2 (200 µg F1 and 100 µg rV270) subunit vaccines and with EV76 live attenuated vaccine against subcutaneous challenge with 6×10(6) CFU of Y. pestis. In the present study, we investigated whether the vaccines can effectively protect immunized animals from any pathologic changes using histological and immunohistochemical techniques. In addition, the glomerular basement membranes (GBMs) of the immunized animals and control animals were checked by electron microscopy. The results show no signs of histopathological lesions in the lungs, livers, kidneys, lymph nodes, spleens and hearts of the immunized animals at Day 14 after the challenge, whereas pathological alterations were seen in the corresponding tissues of the control animals. Giemsa staining, ultrastructural examination, and immunohistochemical staining revealed bacteria in some of the organs of the control animals, whereas no bacterium was observed among the immunized animals. Ultrastructural observation revealed that no glomerular immune deposits on the GBM. These observations suggest that the vaccines can effectively protect animals from any pathologic changes and eliminate Y. pestis from the immunized animals. The control animals died from multi-organ lesions specifically caused by the Y. pestis infection. We also found that subcutaneous infection of animals with Y. pestis results in bubonic plague, followed by pneumonic and septicemic plagues. The histopathologic features of plague in rhesus macaques closely resemble those of rodent and human plagues. Thus, Chinese-origin rhesus macaques serve as useful models in studying Y. pestis pathogenesis, host response and the efficacy of new medical countermeasures against plague.

Objective LcrV is an important component for the development of a subunit vaccine against plague. To reduce immunosuppressive activity of LcrV, a recombinant LcrV variant lacking amino acids 271 to 326 (rV270) was prepared by different methods in this study. Methods A new strategy that produced non-tagged or authentic rV270 protein was designed by insertion of rV270-thrombin-hexahistidine fusion gene into the vector pET24a, or by insertion of hexahistidine-enterokinase-rV270 or hexahistitine-factor Xa-rV270 fusion gene into the vector pET32a. After Co2+ affinity chromatography, a purification strategy was developed by cleavage of His tag on column, following Sephacryl S-200HR column filtration chromatography. Results Removal of His tag by thrombin, enterokinase and factor Xa displayed a yield of 99.5%, 32.4% and 15.3%, respectively. Following Sephacryl S-200HR column filtration chromatography, above 97% purity of rV270 protein was obtained. Purified rV270 that was adsorbed to 25% (v/v) Al(OH)3 adjuvant in phosphate-buffered saline (PBS) induced very high titers of antibody to rV270 in BALB/c mice and protected them (100% survival) against subcutaneous challenge with 106 CFU of Y. pestis virulent strain 141. Conclusion The completely authentic rV270 protein can be prepared by using enterokinase or factor Xa, but they exhibited extremely low cleavage activity to the corresponding recognition site. Thrombin cleavage is an efficient strategy to prepare non-tagged rV270 protein and can be easily operated in a large scale due to its relatively low cost and high cleavage efficacy. The recombinant rV270 can be used as a key component to develop a subunit vaccine of plague.

Long-term protection and antibody response for the subunit vaccine F1-rV270 were determined by using the mouse model. Antibodies to F1 and rV270 were still detectable over a period of 518 days. The complete protection against lethal challenge of Yersinia pestis could be achieved up to day 518 after primary immunization.