ABSTRACT
Aortoenteric fistula is one of the uncommon emergencies and is challenging to navigate for diagnostic testing. Here, we present a clinical case of an aortoduodenal fistula with primary etiology. A 73-year-old female patient with a history of hypertension was admitted to the hospital because of a 1-day history of melena. Ultrasound showed an abdominal aortic aneurysm sized (33 × 46) mm and a hematoma on the wall of the aorta. The patient underwent a gastrointestinal endoscopy with no bleeding point detected. However, the patient suddenly fell into a hemorrhagic shock on day 3 of admission. We rapidly performed fluid resuscitation, blood transfusion, a second gastrointestinal endoscopy, and a computed tomography scan of the abdomen with contrast injection that revealed a fistula from the abdominal aorta into the second segment of the duodenum. The patient was indicated for urgent endovascular aortic repair. Although this technique was successful with 3 abdominal aortic stents, the patient died due to multiorgan failure. Delayed diagnosis is the root cause of primary aortoduodenal fistula treatment failure, so it is important for clinicians to keep aortoduodenal fistula in mind as a possible cause of gastrointestinal bleeding in any patient.
ABSTRACT
Zeolites are three-dimensional aluminosilicates having unique properties from the size and connectivity of their sub-nanometer pores, the Si/Al ratio of the anionic framework, and the charge-balancing cations. The inhomogeneous distribution of the cations affects their catalytic performances because it influences the intra-crystalline diffusion rates of the reactants and products. However, the structural deformation regarding inhomogeneous active regions during the catalysis is not yet observed by conventional analytical tools. Here we employ in situ X-ray free electron laser-based time-resolved coherent X-ray diffraction imaging to investigate the internal deformations originating from the inhomogeneous Cu ion distributions in Cu-exchanged ZSM-5 zeolite crystals during the deoxygenation of nitrogen oxides with propene. We show that the interactions between the reactants and the active sites lead to an unusual strain distribution, confirmed by density functional theory simulations. These observations provide insights into the role of structural inhomogeneity in zeolites during catalysis and will assist the future design of zeolites for their applications.
ABSTRACT
Data centers play an important role in our daily activities. The increasing demand on data centers in both scale and size has led to huge energy consumption that rises the cost of data centers. Besides, environmental impacts also increase considerably due to a large amount of carbon emissions. In this paper, we present a design aimed at green networking by reducing the power consumption for routers and switches. Firstly, we design the Balance Switch on the NetFPGA platform to save consumed energy based on Queue Engineering. Secondly, we design the test-bed system to precisely measure the consumed energy of our switches. Experimental results show that energy saving of our switches is about 30% - 35% of power consumption according to variation of input traffic compared with normal Openflow Switch. Finally, we describe performance evaluations.
