[The role of preventive pancreatic duct stent placement in preventing acute pancreatitis after endoscopic retrograde cholangiopancreatography].

The aim of this study was to investigate the preventive effect of pancreatic duct stent on acute pancreatitis after endoscopic retrograde cholangiopancreatography. A retrospective analysis of the case data of patients who first underwent endoscopic retrograde cholangiopancreatography for choledocholithiasis in the Beijing Friendship Hospital from January 2015 to December 2019 for 5 years. According to whether the pancreatic duct stent was indwelled during the operation, they were divided into pancreatic duct stent group (147 cases) and non-indwelling pancreatic duct stent group (192 cases). The incidence of acute pancreatitis after endoscopic retrograde cholangiopancreatography was compared between the two groups according to COTTON criteria. Independent sample t test, Pearson Chi-square test (χ2) and Fisher's exact test were used to compare groups' differences. There were 2 cases of acute pancreatitis in the pancreatic duct stent group, all of which improved after 48 hours. There were 22 cases of acute pancreatitis in the non-indwelling pancreatic duct stent group, of which 20 cases improved within 48 hours, and the other 2 cases had severe pancreatitis, which improved and discharged after 30 days of treatment. There was significant difference in the incidence of acute pancreatitis between the pancreatic duct stenting group (1.4%) and the group without placement of pancreatic duct stents (11.5%) (χ²=12.905,P<0.001). In conclusion, Pancreatic duct stent may be an effective method to prevent PEP.

Plasmonic nanoparticles embedded in single crystals synthesized by gold ion implantation for enhanced optical nonlinearity and efficient Q-switched lasing.

We report on the synthesis of embedded gold (Au) nanoparticles (NPs) in Nd:YAG single crystals using ion implantation and subsequent thermal annealing. Both linear and nonlinear absorption of the Nd:YAG crystals have been enhanced significantly due to the embedded Au NPs, which is induced by the surface plasmon resonance (SPR) effect in the visible light wavelength band. Particularly, through a typical Z-scan system excited by a femtosecond laser at 515 nm within the SPR band, the nonlinear absorption coefficients of crystals with Au NPs have been observed to be nearly 5 orders of magnitude larger than that without Au NPs. This giant enhancement of nonlinear absorption properties is correlated with the saturable absorption (SA) effect, which is the basis of passive Q-switching or mode-locking for pulsed laser generation. In addition, the linear and nonlinear absorption enhancement could be tailored by varying the fluence of implanted Au+ ions, corresponding to the NP size and concentration modulation. Finally, the Nd:YAG wafer with embedded Au NPs has been applied as a saturable absorber in a Pr:LuLiF4 crystal laser cavity, and efficient pulsed laser generation at 639 nm has been realized, which presents superior performance to the MoS2 saturable absorber based system. This work opens an avenue to enhance and modulate the nonlinearities of dielectrics by embedding plasmonic Au NPs for efficient pulsed laser operation.

The measurement of DLNO and DLCO: A manufacturer's perspective.

The simultaneous measurement of the lung transfer factor for carbon monoxide (DLCO) and nitric oxide (DLNO) is now available as a powerful method for studying the alveolar-capillary gas exchange. However, application of the DLNO-CO technique in daily settings is still limited by some technical drawbacks. This paper provides a manufacturer's overview of the measuring principles, technical challenges and current available solutions for implementing the DLNO-CO measurement in to a marketed device. This includes the recent developments in technology for NO sensors, latest findings on NO uptake and new statistical methods.

[Pulmonary hypertension: from molecular pathophysiology to haemodynamic abnormalities]. / Hypertension pulmonaire: de la physiopathologie moléculaire aux anomalies hémodynamiques.

Pulmonary hypertension (PH) is a complex disorder resulting from many etiologies that cause disturbances of normal pulmonary haemodynamics. Recent breakthroughs have led to a better understanding of the pathophysiology of the disease. In PH, haemodynamic disturbances are closely linked to structural changes and excessive remodeling of pulmonary vessels, leading to progressive narrowing of the pulmonary vascular lumen. Imbalances between pulmonary vasoconstrictors and vasodilators on the one hand, and factors favoring cell proliferation and apoptosis on the other hand, probably account for most cases of PH. This review aims to update readers with the current knowledge on the molecular physiopathology of PH and how this can progress the therapeutic of this disorder.

Preoperative depletion of C3 improves the survival of guinea pig-to-rat cardiac xenograft recipients.

Rat strains with congenitally reduced total hemolytic complement activity do not reject cardiac xenografts hyperacutely. Prolongation of graft survival in the guinea pig-to-C6-deficient PVG rat donor/recipient combination has been observed. However, experience with this model has been complicated by a high postoperative mortality from respiratory distress. The authors hypothesized that placement of the xenograft resulted in local activation of complement, which contributed to remote pulmonary injury leading to respiratory dysfunction. To test this hypothesis, an attempt was made to reduce early complement component activation with the use of an antibody to rat C3 in C6-deficient PVG recipients. Six of eight untreated C6-deficient PVG recipients died in the immediate postoperative period with vigorously beating heart grafts, whereas only 2 of 14 C6-deficient recipients pretreated with anti-rat C3 antibody died within 24 h postoperatively. Although pretreatment with anti-C3 antibody improved survival of recipients, the duration of cardiac xenograft survival was similar whether the recipients were pretreated or not. The use of anti-C3 antibody in C6-deficient rats is a valid approach to studying xenotransplantation in the absence of hyperacute rejection and has an additional advantage in that it does not require the use of expensive reagents such as cobra venom factor.