The Effect of immunonutrition in patients undergoing pancreaticoduodenectomy: a systematic review and meta-analysis.

BACKGROUND: Pancreaticoduodenectomy (PD) is a complex and traumatic abdominal surgery with a high risk of postoperative complications. Nutritional support, including immunonutrition (IMN) with added glutamine, arginine, and ω-3 polyunsaturated fatty acids, can improve patients' prognosis by regulating postoperative inflammatory response. However, the effects of IMN on PD patients' outcomes require further investigation. METHODS: PMC, EMbase, web of science databases were used to search literatures related to IMN and PD. Data such as length of hospital stay, infectious complications, non-infectious complications, postoperative pancreatic fistula (POPF), delayed gastric emptying (DGE), mortality, systemic inflammatory response syndrome (SIRS) duration, IL-6, and C-reactive protein (CRP) were extracted, and meta-analyses were performed on these data to study their pooled results, heterogeneity, and publication bias. RESULTS: This meta-analysis involved 10 studies and a total of 572 patients. The results showed that the use of IMN significantly reduced the length of hospital stay for PD patients (MD = -2.31; 95% CI = -4.43, -0.18; P = 0.03) with low heterogeneity. Additionally, the incidence of infectious complications was significantly reduced (MD = 0.42; 95% CI = 0.18, 1.00, P = 0.05), with low heterogeneity after excluding one study. However, there was no significant impact on non-infectious complications, the incidence of POPF and DGE, mortality rates, duration of SIRS, levels of IL-6 and CRP. CONCLUSION: The use of IMN has been shown to significantly shorten hospital stays and decrease the frequency of infectious complications in PD patients. Early implementation of IMN is recommended for those undergoing PD. However, further research is needed to fully assess the impact of IMN on PD patients through larger and higher-quality studies.

Stress corrosion cracking of NiTi in artificial saliva.

OBJECTIVES: This paper aimed to study the mechanism of the cracking of orthodontic NiTi wire. METHODS: Two orthodontic NiTi wires were subjected: (1) optical and scanning electron microscopy (SEM) to observe the fracture surface; (2) energy dispersive X-ray spectroscopy to determine the composition of the surface product; (3) anodic polarization to remove the surface product. Samples of NiTi alloy were subjected to the constant loading test to study the stress corrosion cracking (SCC) behavior of NiTi shape memory alloy in artificial saliva. RESULTS: The results showed that there were three typical areas at the fracture surface of NiTi orthodontic wire. Area '1' was a tool-made notch. Crack initiated from the root of this notch and propagated to form Area '2', which was perpendicular to the wire axis and covered by surface film. This film consisted of Na, K, Cl, P, S and O except Ni and Ti. The cracking process of NiTi alloy under the constant loading test depended on the pH of saliva and applied stress. The crack length was about 262microm, the longest at 300MPa and pH 3.0. SIGNIFICANCE: A tool-made notch in orthodontic NiTi wires can cause SCC. At high stress and low pH, this NiTi alloy was most sensitive to cracking.

Effect of pH, temperature and Cl- concentration on electrochemical behavior of NiTi shape memory alloy in artificial saliva.

The cooperation of pH, temperature and Cl- concentration on electrochemical behavior of NiTi shape memory alloy in artificial saliva was studied using orthogonal test method. The results showed that the pitting potential for NiTi in artificial saliva decreased at low and high pH; at 25 degrees C, the pitting potential was the lowest compared to those at 10 degrees C, 37 degrees C and 50 degrees C; when the Cl- concentration was not less than 0.05 mol/L the pitting potential decreased with the increase of Cl- concentration. The free corrosion potential of austenitic NiTi was lower than that of mixture of austenite and martensite.