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Background Postoperative thrombocytopenia has been reported to be correlated with adverse events, but the prognostic value of baseline thrombocytopenia is unclear. This study was undertaken to evaluate the relationship between preoperative thrombocytopenia and adverse outcomes in patients with type B aortic dissection who underwent thoracic endovascular aortic repair (TEVAR). Methods A total of 825 patients with acute and sub-acute type B aortic dissection undergoing were TEVAR at a multidisciplinary aortic center were enrolled between January 2010 and December 2017. Patients were stratified on the basis of presence (n=149) or absence (n=676) of thrombocytopenia (platelet count, Results In the enrolled cohort, thrombocytopenia occurred in 149 (18.1%) patients. Patients with thrombocytopenia were older, were more commonly acute stage of TBAD, higher D-dimer level and had higher rates of abdominal vessel involvement and pericardial effusion. During the hospitalization period, 26 patients (3.2%) died, which was significantly higher in the thrombocytopenic group (8.1% versus 2.1%; P=0.001) Multivariate analyses revealed that thrombocytopenia was independently associated with in-hospital mortality (Table). During long-term follow-up (median duration 44.2 months), A total of 62 deaths were reported after discharge, including 40 (64.5%) aortic-related and unknown deaths, of which 12 and 50 patients for thrombocytopenia and non-thrombocytopenia group, respectively. Kaplan-Meier estimated rates of long-term all-cause mortality were higher for thrombocytopenia (log-rank test, P=0.014). Similar results were observed in a subset of aortic-related death (P=0.004) as well as aortic-related and unknown death (P=0.006), not non-aortic related death (P=0.878) (Figure 1). Conclusion Platelet counts, as simple and inexpensive indexes, were reliable to be used as a preoperative risk assessment tool for patients with type B aortic dissection undergoing thoracic endovascular aortic repair. Figure 1. Long-term Mortality Funding Acknowledgement Type of funding source: Public hospital(s). Main funding source(s): This research was supported by grant DFJH201807 from High-level Hospital Construction Project of Guangdong Provincial People's Hospital.

Background This study aimed to analyze the impact of the timing of intervention from presentation of symptoms to TEVAR and its relation to major complications for uncomplicated TBAD. Methods We retrospectively analyzed the data of 390 patients who underwent TEVAR for acute, subacute and chronic uncomplicated type B aortic dissection from January, 2010 to December 2017. Standard univariate and survival methods were used. The primary outcome of interest was in-hospital mortality. The Secondary outcomes of interest was long-term death and in-hospital adverse events, including postoperative coma, postoperative endoleak, postoperative stroke, postoperative spinal cord ischemia, postoperative limb ischemia, postoperative mesenteric ischemia/infraction. Results Of the 390 TEVARs for uncomplicated TBAD, 145 were performed within 14 days of presentation of symptoms (acute), 172 between 14 hours and 90 days (sub-acute), and 73 were beyond 90 days (chronic). Demographic characteristics were similar among groups (Table 1). A slight increase of in-hospital death, post-operative endoleak and limb ischemia, were observed in the acute intervention group compared with the sub-acute group (4.8% vs 2.3%, 11.7% vs 9.3%, 2.8% vs 2.3%, respectively). The chronic group patients had a highest rates of post-operative endoleak. However, there are no significantly differences between the three groups (Table 2). During long-term follow-up (median duration 36.9 months, interquartile range, 22.5–67.7 months), overall survival was similar among groups (log-rank test, P=0.280) (Figure). Conclusion TEVER performed for uncomplicated TBAD within 14 days to the presentation of symptoms, as compared with TEVAR between 14 hours and 90 days or beyond 90 days, neither appear to increase the risk of in-hospital complications nor long-term mortality. Long-term All-cause Mortality Funding Acknowledgement Type of funding source: Public hospital(s). Main funding source(s): This research was supported by grant DFJH201807 from High-level Hospital Construction Project of Guangdong Provincial People's Hospital.

Background Acute type B aortic intramural hematoma (IMH) with ulcer-like projections (ULP) is associated with various adverse aortic-related events (AAE) and recommended for preventive endovascular repair as alternative. However, we have no therapeutic criterion on which to decide preventive treatment. Objectives The purpose of this study was to determine the prognostic value and risk stratification of ULP in patients with acute type B IMH for proper treatment. Methods A retrospective study was conducted on 61 consecutive patients with acute type B IMH and with present of ULP from January 2015 to December 2018 in our center. All patients were treated medically initially and CT scans were performed on admission and during follow-up period. Results During a median follow-up of 4.5 months (range, 0.3 to 49.8 months) from onset, 36 patients (59.0%) had composites of adverse aortic events, including 1 patient died for aortic rupture, 6 patients converted to endovascular repair, 6 progressed into aortic dissection, and 28 developed to aortic enlargement. A cutoff value to estimate risk is 6.0 mm for maximal ULP width (72.2% sensitivity and 84.0% specificity) and 4.0 mm for maximal ULP depth (94.4% sensitivity and 52.0% specificity). Patients with widest (P=0.005) or deepest ULP (P=0.019) in aortic arch and proximal descending thoracic aorta had significant poorer aorta-related event-free survival rates. On multivariate analysis, maximal ULP width ≥6.0 mm [hazard ratio (HR) = 2.569, 95% confidence interval (CI):1.157 to 5.705, P=0.020], maximal ULP depth ≥4.0 mm (HR=5.198, 95% CI: 1.154 to 23.420, P=0.032) and widest ULP in aortic arch and proximal descending thoracic aorta (HR=2.363, 95% CI: 1.012 to 5.517, P=0.047) were independently associated with AAE. ULP with both risk location (widest ULP in aortic arch and proximal descending thoracic aorta) and size (maximal ULP width ≥6.0 mm) were significantly associated with a poorer aortic-related event-free survival rate than others (both P Conclusions Maximal ULP width ≥6.0 mm, maximal ULP depth ≥4.0 mm and widest ULP in aortic arch and proximal descending thoracic aorta are predictive for progression of acute type B aortic intramural hematoma. For patients with ULP in both risk location and size, preventive endovascular treatment should be considered. Figure 1 Funding Acknowledgement Type of funding source: Public hospital(s). Main funding source(s): This research was supported by grant DFJH201807 from High-level Hospital Construction Project of Guangdong Provincial People's Hospital.

Considering the side effects of etomidate, it requires additional anesthetics to reduce the side effects and improve efficacy. Ketamine is often used as an adjunct anesthetic. We hypothesized that etomidate combined with fentanyl was more effective than etomidate combined with ketamine in the anesthesia of pediatric strabotomy. To prove our hypothesis, a prospective randomized controlled clinical study was performed, in which 35 children with strabotomy received etomidate plus ketamine (group A) for anesthesia induction and maintenance and 35 children with strabotomy received etomidate combined with fentanyl (group B). Mean arterial pressure (MAP), heart rate (HR), bispectral index (BIS), anesthesia effect, and emergence agitation and pain were observed before anesthesia induction (T1), after anesthesia induction (T2), at the beginning of the operation (T3), after 10-min operation (T4), and at the end of the operation (T5). Children in group B had significantly lower MAP and HR from T3 to T5, decreased BIS from T2 to T4, better anesthesia effect, and smaller emergence agitation and pain scores at 10 min after entering into postanesthesia care unit (PACU) compared with group A (p 0.05). The mean emergence agitation score in group B was significantly lower than that in group A when the maximum emergence in group B was at 20 min after entering into PACU (p 0.05). In conclusion, etomidate combined with fentanyl plays a good efficacy in anesthesia of pediatric strabotomy compared with etomidate plus ketamine.

Accurately extracting the boundaries of urban built-up area (UBA) borders is vital for scientific urban planning and construction. Based on the land surface emissivity (LSE) and land surface temperature calculation difference between the linear spectral mixing model and Qin normalised difference vegetation index threshold improvement algorithm (ΔLST), a new method for extracting UBA is proposed. The performance of this method is assessed using Landsat images of six typical Chinese cities. The ΔLST threshold method based on the LSE difference demonstrates that the UBA boundary range is accurately extracted, and the overall average accuracy is 86.42%, which has a sufficient universality and application value. Compared with the traditional remote sensing method for extracting UBA, the method proposed in this study avoids the interference of the cloud layer, effectively solving the problem arising due to an easily extracted cloud layer, and the UBA can be accurately identified and extracted under partial cloud coverage. The proposed ΔLST threshold method that is based on the LSE difference makes up for the over-reliance on the urban heat island effect in the UBA method based on the LST inversion results.

Introduction: In China, the perspective of residents and care staff towards the climate of the nursing homes are unknown due to lack of studies in this area.

With the development of manufacturing automation and intelligent increasing speed, the construction in plant management information has been important tasks to promote business innovation ability, improve competitiveness and manufacturing execution. In this paper, UML (Unified Modeling Language) and object-oriented modeling technology were applied to model the static structure and dynamic behavior of the plant management information from requirement analysis to system implementation, including functional requirement model, static structural model, asset management time sequence chart, system physical model and so on. The visualized system analysis method and technology better planned the system design and improved the efficiency of the system development. It will play a guiding role in the object-oriented software development.

A laminar airflow study was performed in a standard operating theatre in Hong Kong, the design of which followed the requirements of the UK Health Technical Memorandum. The study of the ultra-clean ventilation system investigated the effectiveness of the laminar flow in: (i) preventing bioaerosols released by the surgical staff from causing postoperative infection of the patient; and (ii) protecting the surgical team against infection by bacteria from the wound site. Seven cases of computer simulation are presented and the sensitivity of individual cases is discussed. Air velocity at the supply diffuser has been identified as one of the most important factors in governing the dispersion of airborne infectious particles. Higher velocity within the laminar regime is advantageous in minimizing the heat-dissipation effect, and to ensure an adequate washing effect against particulate settlement. Inappropriate positioning of the medical lamps can be detrimental. Omission of a partial wall may increase the infection risk of the surgical team due to the ingression of room air at the supply diffuser periphery. This paper stresses that a successful outcome in preventing airborne infection depends as much on resolving human factors as on overcoming technical obstacles.

The compression of weak optical pulses in a normal group-velocity dispersion regime, by higher-order solitons in the anomalous group-velocity dispersion regime of single-mode fibres, is analysed, both qualitatively and quantitatively, by computer simulation. The results show that copropagating a weak pulse with an intense pump pulse can lead to the generation of a compressed pulse pair in an optical fibre, whose minimum-dispersion wavelength is chosen such that it falls between the pump and the signal wavelength. Numerical simulation also shows that the higher the initial relative peak power of the higher-order solitons, the higher the compression factor and the peak power of the compressed pulse pair. Finally, the physical mechanism based on this compression is analysed in detail.

In recent years, the Evolutionary Structural Optimization (ESO) method has been developed into an effective tool for engineering design. However, no attempts have been made to incorporate random dynamic response constraints. The optimum design of structures with dynamic response constraints is of great importance, particularly in the aeronautical and automotive industries. This paper considers the extension and modification of the ESO method to control the structural random dynamic responses. The random dynamic theory is applied to build an expression of random dynamic response constraints considering engineering requirements. Based on the modal truncation method of eigenderivatives and some approximate process, a set of formulations for sensitivity numbers of mean square random dynamic responses is derived. The algorithm is implemented in optimization software. Several examples are provided to demonstrate the validity and effectiveness of the proposed method.

Distributed video-on-demand servers (DVS) are proposed as a solution to the limited streaming capacity and null scalability of large-scale centralized systems. Server interconnection topology plays an important role in video-on-demand systems' performance. This paper presents an analysis of different topologies and their influence over storage management and distribution, delivery policies performance, refusing requests occurrence, network consumption and scalability. To accomplish the proposal study, we have designed a complete simulation framework for DVS systems. Experimental results obtained under different workload conditions allow us to draw two important conclusions: First, a better connectivity implies a lower mean request service distance and lesser network requirements, improving multicast policies efficiency. Second, topology regularity is essential, as it allows a greater traffic balancing and provides more alternative routing paths. The analysis of global results shows that hypercube presents the best trade-off among all the evaluated metrics, providing a gradual and unlimited scalability for the DVS system.

Surgical site infection risk due to airborne bacteria is a key area of consideration in developing operating theatre ventilation design and monitoring procedures. This paper reviews the recent extensive research into operating theatre ventilation development in relation to the design concepts in operating theatre layout, pressurization and ventilation, particularly the evolvement of ultra-clean ventilation. The findings that led to the current technical standards and the developments of microbial measurements and numerical techniques are discussed. Since the late 1980s, computational fluid dynamics has been a fast developing tool used in the prediction of room air distribution and contaminant dispersion. The basic principles and current practice applying to operating theatre ventilation studies are introduced.

This paper presents an analytical method for vibration eigenvalue sensitivity of cracked beam structures on the basis of variational principles. A physical model of massless rotational spring is adopted to describe the discontinuity of rotation caused by the crack. The discontinuity is further represented as a distributed loading along the beam in form of singular functions. The matrix characteristic equation and eigenvalue sensitivity equation are derived based on variational principles along with the orthogonal series for beams of arbitrary boundary conditions. Analogous analysis is performed on the axial vibrations of a beam. Meanwhile, an exact analytical solution of eigenparameters for a cracked simply supported beam is provided to qualitatively study the effect of crack height on the accuracy of the sensitivity equation. The significance of the proposed method is that it can be easily extended to the case where the beam has multiple cracks by superposition of loads. A simply supported beam is analysed by the proposed method and the exact method. The comparison of results is satisfactory and the factors affecting the accuracy are discussed.