Press Conduction Welding for Secondary Bonding of Aircraft Skin/Stiffener Assemblies Using Carbon Fiber/PEKK Thermoplastic Composites and PEI Adhesive.

This study investigates the secondary bonding of aircraft skin/stiffener assemblies using press conduction welding with carbon fiber/polyetherketoneketone thermoplastic composites and polyetherimide adhesive. Recognizing the challenges posed by conventional welding methods in maintaining material integrity and uniformity, this research explores an alternative methodology that mitigates these issues while ensuring high-strength bonds. The press conduction welding parameters were selected based on single-lap shear tests and applied in the bonding of skin and omega stiffener components. The temperature range was determined using differential scanning calorimetry. The pressure was held at 1 MPa for 180 s. The welding temperature that produced a high-bonding strength was identified experimentally; these key variables were then used in the welding process of the skin and omega stiffener. By analyzing how the fibers tear and the effectiveness of interdiffusion between the plies, we were able to gain insights into the bonding strength and fractured surface. The findings suggest that press conduction welding provides a viable route for secondary bonding in thermoplastic composite structures, highlighting its advantages in terms of processing efficiency and integrity. This study contributes to the understanding of the mechanical behaviors of bonded joints and underscores the significance of temperature control in the welding process.

Laparoscopic duodenal segmental resection and duodenojejunostomy for symptomatic duodenal diverticula in three cases treated at a community hospital.

The duodenum is the second most common site of diverticula following the colon, but is associated with fewer complications than colonic diverticula. Diverticulitis, cholangitis, pancreatitis, perforation, hemorrhage, and blind loop syndrome may occur as complications of duodenal diverticula. Although nonoperative treatment is an option for patients in good condition without signs of sepsis, surgery is generally required for definitive treatment of complications. There are several surgical procedures for symptomatic duodenal diverticula. We performed laparoscopic duodenal segmental resection and duodenojejunostomy without open conversion in three cases. We believe that this procedure is ideal for cases of symptomatic duodenal diverticula when performed by an experienced surgeon with the goal of definitive treatment.

Risk factor, monitoring, and treatment for snakebite induced coagulopathy: a multicenter retrospective study.

BACKGROUND: Snakebite can cause various complications, including coagulopathy. The clinical features of snakebite-associated coagulopathy differ from those of disseminated intravascular coagulation (DIC) caused by other diseases and its treatment is controversial. METHODS: We retrospectively reviewed the medical records of patients hospitalized for snakebite between January 2006 and September 2018. RESULTS: A total of 226 patients were hospitalized due to snakebite. Their median hospital stay was 4.0 days (interquartile range, 2.0 to 7.0 days). Five patients arrived at hospital with shock and one patient died. Twenty-one patients had overt DIC according to the International Society of Thrombosis and Hemostasis scoring system. Two patients developed major bleeding complications. Initial lower cholesterol level at presentation was associated with the development of overt DIC. International normalization ratio (INR) exceeding the laboratory's measurement limit was recorded as late as 4 to 5 days after the bite. Higher antivenom doses (≥18,000 units) and transfusion of fresh frozen plasma (FFP) or cryoprecipitate did not affect prolonged INR duration or hospital stay in the overt DIC patients without bleeding. CONCLUSIONS: Initial lower cholesterol level may be a risk factor for overt DIC following snakebite. Although patients lack apparent symptoms, the risk of coagulopathy should be assessed for at least 4 to 5 days following snakebite. Higher antivenom doses and transfusion of FFP or cryoprecipitate may be unbeneficial for coagulopathic patients without bleeding.

Electrochemiluminescent chemodosimeter based on iridium(III) complex for point-of-care detection of homocysteine levels.

Elevated levels of plasma homocysteine (Hcy) are an independent risk factor for cardiovascular disease. Although a routine, rapid, and simple determination of Hcy levels is highly desired, the existing methods are practically limited because of complicated sample preparation and bulky instrumentation. Herein, we report a chemodosimetric approach for one-step analysis of Hcy levels based on the electrochemiluminescence (ECL). A rationally designed cyclometalated iridium(III) complex possessing a phenylisoquinoline main ligand underwent a selective ring-formation reaction with Hcy to generate a binding adduct, which enabled producing highly luminescent excited states, and yielded strong ECL signals on the surface of electrode without any use of enzymes or antibodies. The level of Hcy was successfully monitored by the ECL increment with a linear correlation between 0 and 40µM in 99.9% aqueous media. The approach required neither sample preparation nor bulky instrument, suggesting the point-of-care testing of Hcy levels, and is potentially useful for routine, cost-effective, and precautionary diagnosis of various cardiovascular diseases.