Background: Chronic lung allograft dysfunction (CLAD) is the major cause of death beyond 2 years after lung transplantation and develops in 50% of all patients by 5 years post-transplant. CLAD is diagnosed on the basis of a sustained drop of 20% for at least 3 months in the forced expiratory volume (FEV1), compared to the best baseline value achieved post-transplant. CLAD presents as two main phenotypes: bronchiolitis obliterans syndrome (BOS) is more common and has better prognosis than restrictive allograft syndrome (RAS). Respiratory oscillometry is a different modality of lung function testing that is highly sensitive to lung mechanics. The current study investigated whether spectral and intrabreath oscillometry can differentiate between CLAD-free, BOS- and RAS-CLAD at CLAD onset, i.e., at the time of the initial 20% drop in the FEV1.Methods: A retrospective, cross-sectional analysis of 263 double lung transplant recipients who underwent paired testing with oscillometry and spirometry at the Toronto General Pulmonary Function Laboratory from 2017 to 2022 was conducted. All pulmonary function testing and CLAD diagnostics were performed following international guidelines. Statistical analysis was conducted using multiple comparisons.Findings: The RAS (n = 6) spectral oscillometry pattern differs from CLAD-free (n = 225) by right-ward shift of reactance curve similar to idiopathic pulmonary fibrosis whereas BOS (n = 32) has a pattern similar to obstructive lung disease. Significant differences were found in most spectral and intrabreath parameters between BOS, RAS, and time-matched CLAD-free patients. Post-hoc analysis revealed these differences were primarily driven by BOS instead of RAS. While no differences were found between CLAD-free and RAS patients with regards to spectral oscillometry, the intrabreath metric of reactance at end-inspiration (XeI) was significantly different (p < 0.05). BOS and RAS were differentiated by spectral oscillometry measure R5, and intrabreath resistance at end expiration, ReE (p < 0.05 for both).Conclusion: Both spectral and intrabreath oscillometry can differentiate BOS-CLAD from CLAD-free states while intrabreath oscillometry, specifically XeI, can uniquely distinguish RAS-CLAD from CLAD-free. Spectral and intrabreath oscillometry offer complementary information regarding lung mechanics in CLAD patients to help distinguish the two phenotypes and could prove useful in prognostication.

The article considers a method for centerless grinding of spherical blanks. The scheme is implemented due to the presence of a trapezoidal helical groove on the driving wheel. The schematic diagram of the proposed method largely corresponds to the traditional centerless grinding scheme, which allows the use of machine tools available in production. It is shown that in the case of centerless grinding of balls, there is an error of basing on the operational size, namely, the diameter of the spherical surface. The adjustment size is mathematically determined when performing the technological operation of centerless grinding of balls, as well as the error of the adjustment size.

This article describes the problem of ensuring effective correction of errors in the form of the spherical surface of the ball during its centerless grinding. The process of embedding ball roughness in the surface of the driving wheel is nonlinear due to the complex form of the roughness and abrasive grains. The mechanism of interaction of the ball with the driving wheel as a process of contacting elastic bodies is analyzed. The value of embedding the abrasive grain size of the driving wheel into the workpiece surface is mathematically determined. It is shown that an increase in the grain of the driving wheel leads to correction of the ball form error during its centerless grinding. At the same time, with increasing wheel abrasive grain, the number of grains per unit surface area of the driving wheel decreases. Based on this, it is concluded that the influence of the characteristic of the driving wheel on the process of correcting errors in the form of the sphere is prevailing.

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Аннотация. Предложено оценивать параметры механических свойств поверхностного слоя рабочих элементов из поликристаллических сверхтвердых композитов на основе кубического нитрида бора режущих инструмент по результатам анализа сканограмм, полученных методом склерометрирования. Представлено теоретическое обоснование метода и рассмотрены термодинамические показатели механических свойств поверхностного слоя-величину активационного барьера запуска процесса производства энтропии и способность к производству энтропии при приложении дозированного воздействия. Приведены результаты экспериментальных исследований работоспособности режущих инструментов из сверхтвердых композитов, полученные при точении закаленных сталей, подтверждающие теоретические выкладки. Ключевые слова: поликристаллические сверхтвердые композиты, кубический нитрид бора, механические свойства, поверхностный слой, режущие инструменты.