Effects of Sodium Phosphate and Sodium Nitrite on the Pitting Corrosion Process of X70 Carbon Steel in Sodium Chloride Solution

In this paper, effects of sodium phosphate (Na₃PO₄) and sodium nitrite (NaNO₂) on the pitting corrosion of X70 carbon steel in 0.10 mol/L NaCl solution were investigated by potentiodynamic polarization technique, electrochemical impedance spectroscopy (EIS) method, scanning electron microscope (SEM) and scanning electrochemical microscope (SECM). The SECM equipment was used to observe the dynamic processes of the pitting corrosion in situ. Na₃PO₄ or NaNO₂ in the sodium chloride solution decreased the local anodic dissolution and increased the pitting resistance of the specimen. By analysis and comparison, it can be concluded that the inhibition effect of Na₃PO₄ is mainly due to the formation of a salt film, while the corrosion inhibition of NaNO₂ is principally attributed to a protective oxide film on the electrode surface.     

Time-Dependent Reliability Analysis of Reinforced Concrete Beams Subjected to Uniform and Pitting Corrosion and Brittle Fracture

Reinforced concrete (RC) beams are basic elements used in the construction of various structures and infrastructural systems. When exposed to harsh environmental conditions, the integrity of RC beams could be compromised as a result of various deterioration mechanisms. One of the most common deterioration mechanisms is the formation of different types of corrosion in the steel reinforcements of the beams, which could impact the overall reliability of the beam. Existing classical reliability analysis methods have shown unstable results when used for the assessment of highly nonlinear problems, such as corroded RC beams. To that end, the main purpose of this paper is to explore the use of a structural reliability method for the multi-state assessment of corroded RC beams. To do so, an improved reliability method, namely the three-term conjugate map (TCM) based on the first order reliability method (FORM), is used. The application of the TCM method to identify the multi-state failure of RC beams is validated against various well-known structural reliability-based FORM formulations. The limit state function (LSF) for corroded RC beams is formulated in accordance with two corrosion types, namely uniform and pitting corrosion, and with consideration of brittle fracture due to the pit-to-crack transition probability. The time-dependent reliability analyses conducted in this study are also used to assess the influence of various parameters on the resulting failure probability of the corroded beams. The results show that the nominal bar diameter, corrosion initiation rate, and the external loads have an important influence on the safety of these structures. In addition, the proposed method is shown to outperform other reliability-based FORM formulations in predicting the level of reliability in RC beams.     

A case of angioimmunoblastic T-cell lymphoma with high serum VEGF preceded by RS3PE syndrome

We report the case of a 76-year-old man diagnosed with angioimmunoblastic T-cell lymphoma (AITL) with high serum vascular endothelial growth factor (VEGF) preceded by Remitting seronegative symmetrical synovitis with pitting edema syndrome. He suffered respiratory discomfort caused by large amounts of pleural effusion. Interestingly, changes in serum VEGF measured over time were similar to changes in pleural effusion. Whether VEGF is related to the pathological condition of AITL is a very important question.     

Mechanistic immunological based classification of rheumatoid arthritis

The classical autoimmunity paradigm in rheumatoid arthritis (RA) is strongly supported by immunogenetics suggesting follicular helper T-cell responses driving high titre specific autoantibodies that pre-dates disease onset. Using the immunological disease continuum model of inflammation against self with “pure” adaptive and innate immune disease at opposite boundaries, we propose a novel immune mechanistic classification describing the heterogeneity within RA. Mutations or SNPs in autoinflammatory genes including MEFV and NOD2 are linked to seronegative RA phenotypes including some so called palindromic RA cases. However, just as innate and adaptive immunity are closely functionally integrated, some ACPA+ RA cases have superimposed “autoinflammatory” features including abrupt onset attacks, severe attacks, self-limiting attacks, relevant autoinflammatory mutations or SNPs and therapeutic responses to autoinflammatory pathway therapies including colchicine and IL-1 pathway blockade. An emergent feature from this classification that non-destructive RA phenotypes, both innate and adaptive, have disease epicentres situated in the extracapsular tissues. This mixed innate and adaptive immunopathogenesis may be the key to understanding severe disease flares, resistant disease subsets that are unresponsive to standard therapy and for therapies that target the autoinflammatory component of disease that are not currently considered by expert therapeutic recommendations.     

RS3PE综合征与肿瘤相关性的探讨(附八例报告)

目的 了解缓和性血清阴性对称性滑膜炎伴凹陷性水肿综合征(RS3PE)的临床特点及与肿瘤的关系。方法 回顾分析8例RS3PE患者的临床表现、实验室检查资料，并复习有关文献。结果 8例均表现为双手及双足的突发性肿胀，血清类风湿因子阴性。8例均有不同肿瘤标记物阳性，其中3例合并肿瘤。结论 8例RS3PE综合征与肿瘤有相关性。     

Nonepisodic angioedema with eosinophilia: a report of two cases and a review of the literature

We report two young female patients who developed sudden-onset nonpitting edema in both hands and lower legs in early autumn with no significant previous or family history. One of these patients showed arthralgia in both wrists and ankles. The clinical symptoms improved without treatment, and they were diagnosed as having nonepisodic angioedema with eosinophilia (NEAE) based on laboratory investigations and the lack of recurrence. The clinical picture of this disease is often similar to that of rheumatologic disorders with tenosynovitis with regard to edema and pain in the distal portion of the extremities. When edema is seen in the bilateral hands and lower legs, particularly in young women, NEAE should be actively considered as a possible diagnosis.     

Impedance of metastable pitting corrosion

A metastable pitting corrosion impedance investigation has been performed. The shape of the dc current is connected with the shape of the impedance diagram. The corrosion rate inside an active pit is charge transfer controlled. The active surface area expansion is proportional to the double layer capacity changes. Changes of the electrolyte resistance inside the pit have been detected.     

Improvement of Pitting-Corrosion Resistance of Ultrafine-Grained 7475 Al Alloy by Aging

The effect of aging on the resistance to pitting corrosion of ultrafine-grained 7475 aluminium (Al) alloy processed by hydrostatic extrusion (HE) is studied. Differences in the microstructure were investigated using secondary electron (SEM) and transmission electron microscopy (TEM). Corrosion tests were performed in 0.1 M NaCl, and characterization of corroded surface was performed. The results of this work show that the pitting susceptibility of ultra-fine grained 7475Al is related to the distribution of MgZn₂ precipitates. After HE, the formation of An ultrafine-grained microstructure at the grain boundaries of ultrafine grains is observed, while subsequent aging results in the formation of MgZn₂ precipitates in the grain interior. Grain refinement increases susceptibility to localized attack, while the subsequent aging improves the overall corrosion resistance and limits the propagation of corrosion attack.     

Enhancing the Corrosion Resistance of Austenitic Steel Using Active Screen Plasma Nitriding and Nitrocarburising

AISI 316L steel was subjected to active screen plasma nitriding and nitrocarburising. The processes were carried out at 440 °C for 6 h. The nitriding process employed an atmosphere of nitrogen and hydrogen, while nitrocarburising was carried out in nitrogen, hydrogen and methane. The processes yielded structures consisting of nitrogen and nitro-carbon expanded austenite, respectively. Microhardness was measured via the Vickers method, surface roughness using an optical profilometer, microstructure by means of light microscopy, while a scanning electron microscope (SEM) served to determine surface topography. Phase composition, lattice parameter and lattice deformation tests were carried out using the X-ray diffraction (XRD) method. Corrosion resistance measurements were performed in a 0.5 M NaCl solution using the potentiodynamic method. The produced layers showed very high resistance to pitting corrosion, while the pitting potential reached 1.5 V, a value that has not yet been recorded in a chloride environment. After the passive layer was broken down, there was a clear deceleration of pitting in the nitrocarburised layer. It was found that in the case of nitro-carbon expanded austenite, pits are formed much slower compared to the nitrogen austenite layer.     

Œdème intermittent, asymétrique et prenant le godet au cours du lupus érythémateux disséminé : deux cas étudiés par imagerie par résonance magnétique nucléaireRemitting asymmetrical pitting oedema in systemic lupus erythematosus: two cases studied with magnetic resonance imaging.

To our knowledge, only three cases of remitting symmetrical pitting oedema in systemic lupus erythematosus have been reported so far. This is the first report of two patients with asymmetrical pitting oedema and systemic lupus erythematosus. The first patient presented two consecutive episodes of unilateral oedema. The first episode involved the distal part of the right lower extremity and remitted spontaneously while the second involved the volar region of the left wrist and distal half of the forearm and promptly responded to steroids. Magnetic resonance imaging of the left wrist and forearm showed tenosynovitis of the flexor tendons and subcutaneous oedema. The second patient instead developed a single episode of pitting oedema of the distal part of the right lower extremity that resolved spontaneously. Magnetic resonance imaging of the right ankle and foot showed subcutaneous oedema without involvement of the tendon sheaths or osteoarticular and ligamental structures. These two cases suggest that pitting oedema in systemic lupus erythematosus may occasionally be asymmetric and associated or not with tenosynovitis.