Phase Transformation in 316L Austenitic Steel Induced by Fracture at Cryogenic Temperatures: Experiment and Modelling

Investigations by electron backscatter diffraction (EBSD) and X-ray diffraction with the use of synchrotron radiation, as well as parallel extended finite element (XFEM) simulations, reveal the evolution of the 316L stainless steel microstructure in the vicinity of a macro-crack developing at the temperature of liquid helium (4.2 K). The fracture propagation induces a dynamic, highly localized phase transformation of face-centred cubic austenite into α’ martensite with a body-centred cubic structure. Synchrotron studies show that the texture of the primary phase controls the transition process. The austenite grains, tending to the stable Brass orientation, generate three mechanisms of the phase transformation. EBSD studies reveal that the secondary phase particles match the ordered austenitic matrix. Hence, interphase boundaries with the Pitsch disorientation are most often formed and α’ martensite undergoes intensive twinning. The XFEM simulations, based on the experimentally determined kinetics of the phase transformation and on the relevant constitutive relationships, reveal that the macro-crack propagates mainly in the martensitic phase. Synchrotron and EBSD studies confirm the almost 100% content of the secondary phase at the fracture surface. Moreover, they indicate that the boundaries formed then are largely random. As a result, the primary beneficial role of martensite as reinforcing particles is eliminated.     

Structure-function analysis of the extracellular domains of the Duffy antigen/receptor for chemokines: characterization of antibody and chemokine binding sites

The Duffy antigen/receptor for chemokines (DARC), a seven-transmembrane glycoprotein carrying the Duffy (Fy) blood group, acts as a widely expressed promiscuous chemokine receptor. In a structure-function study, we analysed the binding of chemokines and anti-Fy monoclonal antibodies (mAbs) to K562 cells expressing 39 mutant forms of DARC with alanine substitutions spread out on the four extracellular domains (ECDs). Using synthetic peptides, we defined previously the Fy6 epitope (22-FEDVW-26), and we characterized the Fya epitope as the linear sequence 41-YGANLE-46. In agreement with these results, mutations of F22-E23, V25 and Y41, G42, N44, L45 on ECD1 abolished the binding of anti-Fy6 and anti-Fya mAbs to K562 cells respectively, Anti-Fy3 binding was abolished by D58-D59 (ECD1), R124 (ECD2), D263 and D283 (ECD4) substitutions. Mutations of C51 (ECD1), C129 (ECD2), C195 (ECD3) and C276 (ECD4 severely reduced anti-Fy3 and CXC-chemokine ligand 8 (CXCL-8) binding. CXCL-8 binding was also abrogated by mutations of F22-E23, P50 (ECD1) and D263, R267, D283 (ECD4). These results defined the Fya epitope and suggested that (1) two disulphide bridges are involved in the creation of an active chemokine binding pocket; (2) a limited number of amino acids in ECDs 1-4 participate in CXCL-8 binding; and (3) Fy3 is a conformation-dependent epitope involving all ECDs. We also showed that N-glycosylation of DARC occurred on N16SS and did not influence antibody and chemokine binding.     

Hyaline matrix in hyalinizing trabecular tumor

Hyalinizing trabecular tumor (HTT) is a rare neoplasm which usually follows an indolent clinical course. The cytologic diagnosis of HTT can be challenging as these neoplasms share cytomorphological features with other thyroid neoplasms and paraganglioma. In fine‐needle aspiration (FNA) smears a diagnosis of papillary thyroid carcinoma (PTC) or suspicion of PTC is often made. Herein we report cytologic findings in two patients with HTT examined by FNA. The key to a correct diagnosis is the recognition of a hyaline and colloid/amyloid‐like material in the background of the smears. Immunocytochemical examination showing aberrant membranous and peripheral cytoplasmic staining for MIB‐1 can help in rendering a correct diagnosis. Diagn. Cytopathol. 2015;43:710–713. © 2014 Wiley Periodicals, Inc.     

A nonischemic forearm exercise test for McArdle disease

Ischemic forearm exercise invariably causes muscle cramps and pain in patients with glycolytic defects. We investigated an alternative diagnostic exercise test that may be better tolerated. Nine patients with McArdle disease, one with the partial glycolytic defect phosphoglycerate mutase deficiency, and nine matched, healthy subjects performed the classic ischemic forearm protocol and an identical protocol without ischemia. Blood was sampled in the median cubital vein of the exercised arm. Plasma lactate level increased similarly in healthy subjects during ischemic (Delta5.1 +/- 0.7mmol L(-1)) and non-ischemic (Delta4.4 +/- 0.3) tests and decreased similarly in McArdle patients (Delta-0.10 +/- 0.02 vs Delta-0.40 +/- 0.10mmol L(-1)). Postexercise peak lactate to ammonia ratios clearly separated patients and healthy controls in ischemic (McArdle, 4 +/- 2 [range, 1-12]; partial glycolytic defect phosphoglycerate mutase deficiency, 6; healthy, 33 +/- 4 [range, 17-56]) and non-ischemic (McArdle, 5 +/- 1 [range, 1-10]; partial glycolytic defect phosphoglycerate mutase deficiency, 5; healthy, 42 +/- 3 [range, 35-56]) protocols. Similar differences in lactate to ammonia ratio between patients and healthy subjects were observed in two other work protocols using intermittent handgrip contraction at 50% and static handgrip exercise at 30% of maximal voluntary contraction force. All patients developed pain and cramps during the ischemic test, and four had to abort the test prematurely. No patient experienced cramps in the non-ischemic test, and all completed the test. The findings indicate that the diagnostic ischemic forearm test for glycolytic disorders should be replaced by an aerobic forearm test.     

Quality of Life of Cancer Patients Receiving Enteral Nutrition: A Systematic Review of Randomized Controlled Trials

Most studies confirm the beneficial effects of enteral nutrition on the quality of life, but some studies indicate an inverse association and its detrimental impacts. However, there are insufficient data on the effects of enteral nutrition on the quality of life of cancer patients. This systematic review aimed to describe the influence of applied enteral nutrition on the quality of life of cancer patients, based on the results of randomized controlled trials. It was registered in the PROSPERO database (CRD42021261226) and conducted based on the PRISMA guidelines. The searching procedure was conducted using the PubMed and Web of Science databases, as well as Cochrane Library, and it included studies published until June 2021. It was conducted to select randomized controlled trials assessing the influence of enteral nutrition (compared with the other model of nutrition) on the quality of life of cancer patients. A general number of 761 records were screened and a final number of 16 studies were included in the systematic review. The studies were included and assessed by two independent researchers, while the risk of bias was analyzed using the Newcastle–Ottawa Scale (NOS). Studies compared patients treated with and without enteral nutrition, patients treated with various methods of enteral nutrition or with enteral diets of various content, as well as patients treated with enteral and parenteral nutrition. Within the included studies, the majority were conducted in patients with cancers located in various parts of the body, or diverse areas within the gastrointestinal system, while some studies were conducted in specific populations of patients with a defined cancer location—esophagus, stomach, or ovary. The duration of applied enteral nutrition within the included studies was diversified—from two weeks or less to half a year or even more. The vast majority of studies used well-known and validated tools to assess the quality of life, either developed for a specific group of head/neck, esophagus/stomach, and ovary cancer patients or developed for more general patient populations. Most studies concerning patients treated with and without enteral nutrition supported applying enteral nutrition, which was concluded in seven studies out of ten (including four studies with a low risk of bias). The other important observations to be emphasized—formulated based on the studies with a low risk of bias—presented the role of oral supportive nutrition guided by a dietitian, as well as the beneficial role of enteral and parenteral nutrition, combined. In spite of a relatively low number of randomized controlled trials assessing the influence of enteral nutrition on the quality of life of cancer patients, which should be considered as a limitation, the results were promising. Most studies supported the positive influence of enteral nutrition on the quality of life, either assessed based on the psychological measures of the quality of life or by considering the other potential determinants (e.g., malnutrition, complications, etc.). Taking this into account, enteral nutrition should be applied whenever possible, both to prevent and treat malnutrition in cancer patients. However, considering the limited number of studies conducted so far, further research conducted in homogenic populations of patients is necessary.