Objective To design a search and rescue UAV that is portable and user-friendly in order to meet the needs of rescue personnel on the battlefield.Methods Three-dimensional design software CATIA was used to complete the structural design of the UAV body.In order to make full use of the internal space of the UAV body,folding wings were adopted to reduce the volume of the UAV.By using ABAQUS,the finite elements of the key parts of the UAV were analyzed before the modal analysis of the whole vehicle was conducted to verify the reliability of the structure.The robot simulation software Webots was used for motion simulation of the UAV.Results Simulation analysis and test verification suggested that the structural design of the UAV was well-grounded.It could be quickly and properly deployed by means of hand launch or barrels,which made it easier for rescuers to use the UAV.Conclusion The design and simulation research of UAVs with portable folding wings for search and rescue is of great significance for the research and development of physical prototypes.This study is expected to stimulate new ideas for the development of rescue equipment in the PLA,and contribute to miniaturization of UAVs.

Objective:To investigate the status quo and influencing factors of knowledge,attitude and behavior of hospice care among medical staff in medical and nursing institutions in Liaoning Province,so as to provide a theoretical reference for further proposing the promotion strategy of hospice care services in medical and nursing institutions in Liaoning Province.Methods:The knowledge,attitude and behavior questionnaire of hospice care designed by Pan Qini et al.was used to investigate the knowledge,attitude and behavior status quo of 153 medical staff in the medical and nursing institutions in Liaoning Province by convenient sampling method.Multiple linear regression analysis was used to analyze the influencing factors of knowledge,attitude and behavior of hospice care among medical staff.Results:The total score of knowledge,attitude and behavior of hospice care of medical staff in medical and nursing institutions was(78.93±15.45),the score of knowledge dimension was(0.42±1.58),the score of attitude dimension was(33.67±8.10),and the score of behavior dimension was(44.84±10.25).There were differences in the scores of knowledge,attitude and behavior in the different nature of medical and nursing institutions,whether they had religious beliefs,the experience of caring for seriously ill relatives,the number of end-stage patients treated/cared for in the past year,the satisfaction with the intensity of work,the support of family members for hospice care,the emotional impact of engaging in hospice care,whether they were willing to stay and continue to engage in hospice care.Whether they had religious beliefs and the number of end-stage patients treated/cared for in the past year were the main influencing factors of the knowledge,attitude and behavior level of hospice care among medical staff(P＜0.05).Conclusions:The knowledge,attitude and behavior of hospice care among medical staff in medical and nursing institutions in Liaoning Province are at a medium level,and the levels of knowledge,attitude,and behavior need to be further improved.The management personnel of medical and nursing institutions should actively supervise and urge the development of targeted professional training,and strengthen the concept of hospice care of medical staff,so as to comprehensively improve the service level of hospice care of medical staff.

This study aimed to investigate the influence of anti-cross-reactive carbohydrate determinant IgE antibodies (anti-CCD IgE) on the detection of allergen-specific IgE (sIgE) antibodies, as well as the application value of anti-CCD IgE adsorbents in detecting allergen sIgE. In this cross-sectional study, a total of 2 636 test samples from patients who received treatment in West China Hospital of Sichuan University and tested allergen sIgE using the western blot method from October 2020 to May 2021 were analyzed. In these samples, 709 samples tested postive of allergen sIgE. 46 stochastic venous serum samples that tested positive in both sIgE and anti-CCD IgE and 1 serum sample that tested positive in sIgE but negative in anti-CCD IgE were collected. These samples were processed by anti-CCD IgE adsorbents, followed by allergen sIgE detection. The difference between the two detection results before and after adsorption was analyzed. The allergen test results showed that the positive rate of anti-CCD IgE in samples was 2.6% (69/2 636) during the period of sample collection. After treatment with anti-CCD IgE adsorbents, the top three allergen-sIgE of the positive rate changed from tree combination 2 (willow/poplar/elm), common ragweed and peanut to dust mite combination, cockroach and crab. The positive anti-CCD IgE results of 46 samples all turned negative and the total positive sIgE antibody dropped by 62.8%; the positive rate of sIgE antibodies with the class result ≥2 significantly decreased after treatment with anti-CCD IgE adsorbents, especially the positive rate of common ragweed dropped by 96.2%. The results of positive samples showed that multiple sIgE antibodies declined by different ranges, involving up to 11 antibodies with a maximum decline of 4 classes. Strongly positive sIgE antibodies (the class result ≥4) also had a high conversion rate of negative (25.0%-100%). The positive sIgE antibodies in about 60% of the samples decreased by more than 2, and the sIgE antibodies in 17.4% of the samples turned completely negative. There was no change in the allergen sIgE detection results of the sample with negative anti-CCD IgE after treatment. In conclusion, sIgE antibodies including targeting common ragweed, humulus, tree combination 2 (willow/poplar/elm), etc. are susceptible to false positives caused by anti-CCD IgE. Treatment of samples with anti-CCD IgE adsorbents can significantly reduce the risk of false positives caused by anti-CCD IgE. It is necessary to pretreat samples that were anti-CCD IgE positive with anti-CCD IgE adsorbents, which can make laboratory results more accurate and provide a reference for diagnosis and prevention of allergic diseases.

This study aimed to investigate the influence of anti-cross-reactive carbohydrate determinant IgE antibodies (anti-CCD IgE) on the detection of allergen-specific IgE (sIgE) antibodies, as well as the application value of anti-CCD IgE adsorbents in detecting allergen sIgE. In this cross-sectional study, a total of 2 636 test samples from patients who received treatment in West China Hospital of Sichuan University and tested allergen sIgE using the western blot method from October 2020 to May 2021 were analyzed. In these samples, 709 samples tested postive of allergen sIgE. 46 stochastic venous serum samples that tested positive in both sIgE and anti-CCD IgE and 1 serum sample that tested positive in sIgE but negative in anti-CCD IgE were collected. These samples were processed by anti-CCD IgE adsorbents, followed by allergen sIgE detection. The difference between the two detection results before and after adsorption was analyzed. The allergen test results showed that the positive rate of anti-CCD IgE in samples was 2.6% (69/2 636) during the period of sample collection. After treatment with anti-CCD IgE adsorbents, the top three allergen-sIgE of the positive rate changed from tree combination 2 (willow/poplar/elm), common ragweed and peanut to dust mite combination, cockroach and crab. The positive anti-CCD IgE results of 46 samples all turned negative and the total positive sIgE antibody dropped by 62.8%; the positive rate of sIgE antibodies with the class result ≥2 significantly decreased after treatment with anti-CCD IgE adsorbents, especially the positive rate of common ragweed dropped by 96.2%. The results of positive samples showed that multiple sIgE antibodies declined by different ranges, involving up to 11 antibodies with a maximum decline of 4 classes. Strongly positive sIgE antibodies (the class result ≥4) also had a high conversion rate of negative (25.0%-100%). The positive sIgE antibodies in about 60% of the samples decreased by more than 2, and the sIgE antibodies in 17.4% of the samples turned completely negative. There was no change in the allergen sIgE detection results of the sample with negative anti-CCD IgE after treatment. In conclusion, sIgE antibodies including targeting common ragweed, humulus, tree combination 2 (willow/poplar/elm), etc. are susceptible to false positives caused by anti-CCD IgE. Treatment of samples with anti-CCD IgE adsorbents can significantly reduce the risk of false positives caused by anti-CCD IgE. It is necessary to pretreat samples that were anti-CCD IgE positive with anti-CCD IgE adsorbents, which can make laboratory results more accurate and provide a reference for diagnosis and prevention of allergic diseases.

新冠病毒感染疫情严重威胁着世界各国人民的生命健康。目前，对病毒感染的防治研究主要集中在抑制病毒与分子受体的结合上。AXL作为新发现的严重急性呼吸综合征冠状病毒2型（SARS-CoV-2）受体，在协助病毒感染人体呼吸系统中发挥着重要作用，是未来临床干预的潜在靶点。本研究对已发表的单细胞测序数据进行整理和分析，发现AXL在年轻人肺细胞中的表达水平明显高于老年人。人胚肺二倍体成纤维细胞（2BS）是衰老研究的公认细胞株。本文采用2BS细胞构建复制性细胞衰老模型，发现年轻细胞中AXL的蛋白水平明显高于衰老细胞，据此推测年轻人感染的风险可能更高，需要注意防护。我们发现一种羊栖菜褐藻多糖硫酸酯组分（SFW-3）可显著下调年轻2BS细胞中AXL的表达水平，表明SFW-3具有一定的抗SARS-CoV-2感染的研究价值，同时表明2BS细胞株也可作为潜在的SARS-CoV-2体外感染模型。
Humans ; SARS-CoV-2 ; Sargassum/metabolism* ; Diploidy ; Sulfates/metabolism* ; COVID-19 ; Polysaccharides/pharmacology* ; Lung

Objective:To investigate the diagnostic accuracy of serological indicators and evaluate the diagnostic value of a new established combined serological model on identifying the minimal hepatic encephalopathy (MHE) in patients with compensated cirrhosis.Methods:This prospective multicenter study enrolled 263 compensated cirrhotic patients from 23 hospitals in 15 provinces, autonomous regions and municipalities of China between October 2021 and August 2022. Clinical data and laboratory test results were collected, and the model for end-stage liver disease (MELD) score was calculated. Ammonia level was corrected to the upper limit of normal (AMM-ULN) by the baseline blood ammonia measurements/upper limit of the normal reference value. MHE was diagnosed by combined abnormal number connection test-A and abnormal digit symbol test as suggested by Guidelines on the management of hepatic encephalopathy in cirrhosis. The patients were randomly divided (7∶3) into training set ( n=185) and validation set ( n=78) based on caret package of R language. Logistic regression was used to establish a combined model of MHE diagnosis. The diagnostic performance was evaluated by the area under the curve (AUC) of receiver operating characteristic curve, Hosmer-Lemeshow test and calibration curve. The internal verification was carried out by the Bootstrap method ( n=200). AUC comparisons were achieved using the Delong test. Results:In the training set, prevalence of MHE was 37.8% (70/185). There were statistically significant differences in AMM-ULN, albumin, platelet, alkaline phosphatase, international normalized ratio, MELD score and education between non-MHE group and MHE group (all P<0.05). Multivariate Logistic regression analysis showed that AMM-ULN [odds ratio ( OR)=1.78, 95% confidence interval ( CI) 1.05-3.14, P=0.038] and MELD score ( OR=1.11, 95% CI 1.04-1.20, P=0.002) were independent risk factors for MHE, and the AUC for predicting MHE were 0.663, 0.625, respectively. Compared with the use of blood AMM-ULN and MELD score alone, the AUC of the combined model of AMM-ULN, MELD score and education exhibited better predictive performance in determining the presence of MHE was 0.755, the specificity and sensitivity was 85.2% and 55.7%, respectively. Hosmer-Lemeshow test and calibration curve showed that the model had good calibration ( P=0.733). The AUC for internal validation of the combined model for diagnosing MHE was 0.752. In the validation set, the AUC of the combined model for diagnosing MHE was 0.794, and Hosmer-Lemeshow test showed good calibration ( P=0.841). Conclusion:Use of the combined model including AMM-ULN, MELD score and education could improve the predictive efficiency of MHE among patients with compensated cirrhosis.

Objective To compare the principles and performance of three Hough transform algorithms(standard Hough transform,gradient based Hough transform,and random Hough transform)in order to establish a suitable control basis for precise and rapid recognition of targets and acquisition of target center coordinates for craniocerebral puncture robots.Methods A simulation environment in MATLAB software was built to study and analyze image feature recognition,filtering,edge detection,cumulative voting and other processing engineering.Contour recognition and fitting of target circles were achieved in multiple scenarios before their center coordinates were obtained.The recognition and fitting performance of these algorithms was quantitatively compared.Finally,a better detection algorithm based on the actual environment of the craniocerebral puncture robot was determined.Results The standard Hough transform algorithm had the largest error between the mark circle and the target circle,and the running time of this algorithm was the longest due to large computation.The detection speed of the random Hough transform algorithm was lower than that of the gradient-based Hough transform algorithm,but the fitting accuracy was slightly better than that of the standard Hough transform algorithm.The speed and accuracy of circle fitting based on the gradient Hough transform algorithm had significant advantages over the other two.Conclusion The gradient based Hough transform algorithm is more suitable for obtaining the target center coordinates of the craniocerebral puncture robot system.

Objective To investigate the efficacy and safety of bivalirudin versus unfractionated heparin during perioperative primary percutaneous coronary intervention(PCI)in elderly patients with acute ST-segment elevation myocardial infarction(STEMI).Methods A total of 423 elderly patients with acute STEMI who underwent primary PCI in our hospital were consecutively en-rolled in this study.According to different perioperative anticoagulant regimens,they were divided into bivalirudin group(187 cases)and unfractionated heparin group(236 cases).Baseline data,characteristics of interventional procedures and complications during hospitalization were ana-lyzed.Primary endpoint was major adverse cardiac or cerebral events(MACCE).Secondary end-points were net adverse clinical events.Other observational indicators included stent thrombosis,acquired thrombocytopenia,BARC types 1-2 bleeding and total bleeding events.Results In-hospital MACCE and all-cause mortality were significantly lower in the bivalirudin group than unfractionated heparin group(3.7％vs 9.7％,P=0.021;3.7％vs 8.9％,P=0.039).Univariate logistic regression analysis showed that perioperative application of bivalirudin significantly reduced all-cause mortality in the patients with Killip grade Ⅰ and creatinine clearance ≥60 ml/min when compared with unfractionated heparin(P＜0.05).Conclusion In elderly patients with acute STEMI,perioperative use of bivalirudin significantly reduces the incidences of MACCE and all-cause death during hospitalization,especially in the patients with Killip grade Ⅰ and creatinine clearance ≥60 ml/min.

Objectives:To investigate the clinical and genetic features of young Chinese patients with myeloproliferative neoplasms (MPN) .Methods:In this cross-sectional study, anonymous questionnaires were distributed to patients with MPN patients nationwide. The respondents were divided into 3 groups based on their age at diagnosis: young (≤40 years) , middle-aged (41-60 years) , and elderly (>60 years) . We compared the clinical and genetic characteristics of three groups of MPN patients.Results:1727 assessable questionnaires were collected. There were 453 (26.2%) young respondents with MPNs, including 274 with essential thrombocythemia (ET) , 80 with polycythemia vera (PV) , and 99 with myelofibrosis. Among the young group, 178 (39.3%) were male, and the median age was 31 (18-40) years. In comparison to middle-aged and elderly respondents, young respondents with MPN were more likely to present with a higher proportion of unmarried status (all P<0.001) , a higher education level (all P<0.001) , less comorbidity (ies) , fewer medications (all P<0.001) , and low-risk stratification (all P<0.001) . Younger respondents experienced headache (ET, P<0.001; PV, P=0.007; MF, P=0.001) at diagnosis, had splenomegaly at diagnosis (PV, P<0.001) , and survey (ET, P=0.052; PV, P=0.063) . Younger respondents had fewer thrombotic events at diagnosis (ET, P<0.001; PV, P=0.011) and during the survey (ET, P<0.001; PV, P=0.003) . JAK2 mutations were found in fewer young people (ET, P<0.001; PV, P<0.001; MF, P=0.013) ; however, CALR mutations were found in more young people (ET, P<0.001; MF, P=0.015) . Furthermore, mutations in non-driver genes (ET, P=0.042; PV, P=0.043; MF, P=0.004) and high-molecular risk mutations (ET, P=0.024; PV, P=0.023; MF, P=0.001) were found in fewer young respondents. Conclusion:Compared with middle-aged and elderly patients, young patients with MPN had unique clinical and genetic characteristics.

Objective:To evaluate the immunogenicity of recombinant factor H binding protein(fHBP) by detecting serum antibody titer and serum bactericidal antibody test (SBA).Methods:fHBP sequence was selected and synthesized, connected to plasmid pET43.1a, transformed to Escherichia coli BL21(DE3), and expressed two recombinant fHBP proteins, included two subfamilies, fHBPA and fHBPB. After purification, the recombinant fHBP proteins were immunized to rabbits and mice. The immune antiserum titer and the bactericidal titer to epidemic strains of meningococcal bacteria group B were measured by ELISA and SBA respectively. Results:The antiserum titer of fHBP immunized rabbits was greater than 2.0×10 6, and that of immunized mice was not less than 1.0×10 6. fHBP immunized rabbit serum had bactericidal titer more than 1∶128 to 41 strains A subfamily and 20 strains B subfamily in the SBA against 69 endemic strains, and there was no cross-protection between the subfamily bacteria. The bactericidal titers of mouse serum immunized fHBPA to strains A subfamily such as Nm210902 Nm211009、Nm450522 were 1∶1 024, 1∶608、1∶861, to Nm510703、Nm311304、Nm431002 were 1∶234、1∶861、1∶430 respectively, and mouse serum immunized fHBP B to strains B subfamily Nm311302、Nm311304、Nm431002 were 1∶876、1∶274、1∶1858, all of three strains were positive in bactericidal titers. Conclusions:the titer of fHBP antiserum was higher than 1.0×10 6, the bactericidal titer was no less than 1∶128 to 61 epidemic strains, and it has a 94.2% protective effect on 69 meningococcal epidemic strains group B.