Number Of Cycles Research Articles

Worldwide fluctuations in carbon emissions: Characterization and synchronization

Coordinated and cooperative efforts among international actors are necessary for climate policy effectiveness. From a macroeconomic perspective, the greater the synchronization of business cycles, the greater the potential for policy coordination and joint decision making. In light of the procyclical behaviour between the business cycle and the carbon emission cycle, this work tries to shed light on carbon emission fluctuations of sixteen major developed and developing economies during 1946–2021. In analogy with “classical” business cycle research, the analysis dates expansionary and contractionary phases, determines their durations and amplitudes. It also inspects emission synchronization between pairs and groups of countries in order to assess their degree of carbon integration. Carbon emission fluctuations are mostly an expansionary phenomenon. Compared to developed countries, developing countries feature on average longer cycles (i.e., a lower number of full cycles), less time spent in contraction, longer expansionary phases, shorter contractionary phases and larger absolute amplitudes. Pairwise carbon emission fluctuations are synchronized in 34.2% cases. Developed economies have their own common emission cycle. As for developing economies, results are heterogeneous. Only part of them, in fact, shows evidence of a common carbon emission cycle despite a relatively recent history of cooperation, heterogeneous geographical locations and socio-cultural features.

Experimental study and numerical simulation verification of the macro- and micromechanical properties of the sandstone–concrete interface under freeze–thaw cycles

In cold-region tunnel engineering, the bonding surface between concrete and surrounding rock is highly susceptible to engineering disasters such as the cracking of support structures under the influence of freeze-thaw cycles, which severely affects the stability of tunnel engineering. This study investigates the macroscopic and microscopic mechanical properties of the sandstone–concrete interface under freeze–thaw cycles and reveals the microdamage and fracture evolutionary laws during the freeze–thaw loading process via the coupled expansion of water–ice particle phase changes via particle flow numerical simulation methods, aiming to provide theoretical support for the design and construction of rock–soil and tunnel engineering in high-altitude frozen soil areas. The results indicate that the interface strength characteristics of the sandstone–concrete specimens exhibit a stable decreasing trend with an increase in the number of freeze-thaw cycles and a decrease in roughness. Taking the most unfavorable condition as an example, the exacerbation of freeze-thaw deterioration resulted in shear strength reductions of 16.53%, 27.01%, and 37.17% for specimens (JRC=3.727), while an increase in roughness led to shear strength increases of 11.00% and 15.14% for specimens (NT=60 cycles). The acoustic emission characteristics during the loading process of the sandstone–concrete interface specimens reflect the microcracking evolutionary activity of the specimens quite well, and setting 1.0 as the recommended value for the precursor determination of the b-value and CV(k) index is most reasonable. Under freeze-thaw cycles, cracks first initiate partial microcracks at the interface and on the outer side of the specimen, primarily dominated by tensile cracks and evolving with a "slow–fast" trend toward both sides of the interface. Under shear stress, particles at the interface first undergo slip dislocation due to their lower bonding strength, generating cracks, subsequently inducing significant displacement of particles on both sides of the interface, resulting in crack propagation toward both sides of the interface, ultimately penetrating and forming shear bands leading to macroscopic failure.

The effect of retained austenite on rolling/sliding contact fatigue of high carbon steel

Rolling contact fatigue (RCF) is significantly influenced by retained austenite (RA). To study the impact of the RA on fatigue life and pit formation, a high carbon steel was tested with three different RA levels ranging from 5 % to 23 % (volume fraction). The variations of the RA with respect to the number of cycles and along the depth were inspected by X-ray diffraction (XRD) technique. The microstructures before and after RCF were characterized by scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). The majority of RA was transformed into martensite at an early stage (before 3×104 cycles) in both surface and subsurface. And the remaining small fraction of RA was transformed during the rest of the testing life, with a final content lower than 5 %. As the depth increased, the rate of RA transformation decreased. The specimen with the highest RA level of 23 % showed the shortest life. The longest RCF life was seen in the specimen with a medium RA level of 15 % due to the formation of the well-developed hardened layer, which helps resisting the pit formation. Based on these observations, it was suggested that a medium level of RA is beneficial for the improvement of the RCF life of the present high carbon steel. The combined effect of the hardness and the RA acts together on resistance to pit formation.

Augmenting sixth graders’ science process skills and learning outcomes on plant breeding materials using the outdoor learning method at SDN 23 Pulubala Gorontalo district

This class action research explores how to augment sixth graders’ science process skills and learning outcomes on plant breeding materials using the outdoor learning method at SDN 23 Pulubala Gorontalo District. It was class action research. 15 students, eight males and seven females, acted as subjects. Data analysis results and discussion led us to conclusions that (1) students who demonstrated science process skills with a Good category after using the outdoor learning method in Cycle I increased by number in Cycle II, from eight (48%) to 14 (93%). In other words, the increase involved six students (40%), (2) students who achieved learning outcomes with a completeness category after using the outdoor learning method in Cycle I also increased by number in Cycle II, from seven (48%) to 13 (88%). The increase hence involved six students (40%), and (3) the number of students attained a good category after using the outdoor learning method in Cycle I increased by number in Cycle II, from 7 (47%) to 13 (88%). The increase thus involved six students (72%).

Parental conflict driven regulation of endosperm cellularization by a family of Auxin Response Factors.

The endosperm is a reproductive tissue supporting embryo development. In most flowering plants, the initial divisions of endosperm nuclei are not succeeded by cellularization; this process occurs only after a specific number of mitotic cycles have taken place. The timing of cellularization significantly influences seed viability and size. Previous research implicated auxin as a key factor in initiating nuclear divisions and determining the timing of cellularization. Here we uncover the involvement of a family of clustered auxin response factors (cARFs) as dosage-sensitive regulators of endosperm cellularization. cARFs, maternally expressed and paternally silenced, are shown to induce cellularization, thereby restricting seed growth. Our findings align with the predictions of the parental conflict theory, suggesting that cARFs represent major molecular targets in this conflict. We further demonstrate a recurring amplification of cARFs in the Brassicaceae, suggesting an evolutionary response to parental conflict by reinforcing maternal control over endosperm cellularization. Our study highlights that antagonistic parental control on endosperm cellularization converges on auxin biosynthesis and signalling.

The High Temperature Strength of Single Crystal Ni‐base Superalloys – Re‐visiting Constant Strain Rate, Creep, and Thermomechanical Fatigue Testing

The present work takes a new look at the high temperature strength of single crystal (SX) Ni‐base superalloys. It compares high temperature constant strain rate (CSR) testing, creep testing, and out‐of‐phase thermomechanical fatigue (OP TMF) testing, which represent key characterization methods supporting alloy development and component design in SX material science and technology. The three types of tests are compared using the same SX alloy, working with precisely oriented <001>‐specimens and considering the same temperature range between 1023 and 1223 K, where climb controlled micro‐creep processes need to be considered. Nevertheless, the three types of tests provide different types of information. CSR testing at imposed strain rates of 3.3 × 10−4 s−1 shows a yield stress anomaly (YSA) with a YSA stress peak at a temperature of 1073 K. This increase of strength with increasing temperature is not observed during constant load creep testing at much lower deformation rates around 10−7 s−1. Creep rates show a usual behavior and increase with increasing temperatures. During OP‐TMF loading, the temperature continuously increases/decreases in the compression/tension part of the mechanical strain‐controlled cycle (±0.5%). At the temperature, where the YSA peak stress temperature is observed, no peculiarities are observed. It is shown that OP‐TMF life is sensitive to surface quality, which is not the case in creep. A smaller number of cycles to failure is observed when reducing the heating rate in the compression/heating part of the mechanical strain‐controlled OP‐TMF cycle. The results are discussed on a microstructural basis, using results from scanning and transmission electron microscopy, and in light of previous work published in the literature.

Effect of the cycle number of multistep sintering on the properties of FeSe0.4Te0.6 superconductors

AbstractFeSe0.4Te0.6 polycrystal bulks were synthesized using the solid‐state sintering method. We developed a novel multistep sintering process and studied the impact of the sintering cycle number. Different cycles of multistep sintering, ranging from one to four cycles were systematically arranged. It was found that the superconducting properties of the FeSe0.4Te0.6 polycrystal bulk using three cycles of sintering surpassed those of other samples, reaching a maximum of = 13.4 K, = 14.7 K, and a minimum of ∆ = 1.3 K. And the superconducting current density at 4 K reached 1.77 × 104 A/cm2, exhibiting a weak fishtail effect. At 9 K, a composite pinning effect emerged, consisting of normal point pinning and ∆κ surface pinning. The enhancement in superconductivity is attributed to improve uniformity in grain arrangement and more effective element diffusion. After multiple sintering cycles, the stacked grains exhibited increased thickness and the grain arrangement became dense.

Analysis of sequential chemotherapy efficacy in ovarian epithelial carcinoma, fallopian tube carcinoma and primary peritoneal carcinoma

Objective: To explore the sequential chemotherapy efficacy of different chemotherapeutic regimens in ovarian epithelial carcinoma, fallopian tube carcinoma, and primary peritoneal carcinoma. Methods: A retrospective analysis was conducted on clinical and pathological data of 100 patients with platinum-sensitive ovarian epithelial carcinoma, fallopian tube carcinoma, and primary peritoneal carcinoma treated at Peking University Peopel's Hospital from January 1992 to January 2019. All patients underwent staging surgery or cytoreductive surgery followed by adjuvant chemotherapy. Based on different postoperative adjuvant chemotherapy regimens, patients were divided into the sequential chemotherapy group (70 cases) and the conventional chemotherapy group (30 cases). Clinical and pathological characteristics, chemotherapy efficacy, adverse reactions, and prognosis were compared between the two groups. Results: (1) Clinical and pathological characteristics: the age, tumor types (including ovarian epithelial carcinoma, fallopian tube carcinoma, and primary peritoneal carcinoma), pathological types, International Federation of Gynecology and Obstetrics (FIGO) stage, postoperative residual disease size, presence of neoadjuvant chemotherapy, and total number of chemotherapy cycles were compared between the sequential chemotherapy group and the conventional chemotherapy group. There were no statistically significant differences observed in these characteristics between the two groups (all P>0.05). (2) Chemotherapy efficacy: the median sum of complete response (CR)+partial response (PR) duration in the sequential chemotherapy group was 80.0 months (range: 39 to 369 months), whereas in the conventional chemotherapy group, it was 28.0 months (range: 13 to 52 months). A statistically significant difference was observed between the two groups (Z=-7.82, P<0.001). (3) Chemotherapy adverse reactions: in the sequential chemotherapy group, 55 cases (79%, 55/70) experienced bone marrow suppression and 20 cases (29%, 20/70) had neurological symptoms. In the conventional chemotherapy group, these adverse reactions occurred in 11 cases (37%, 11/30) and 2 cases (7%, 2/30), respectively. Statistically significant differences were observed between the two groups for both bone marrow suppression and neurological symptoms (all P<0.05). For the other chemotherapy adverse reactions compared between the two groups, no statistically significant differences were observed (all P>0.05). (4) Prognosis: during the follow-up period, the recurrence rate in the sequential chemotherapy group was 73% (51/70) and in the conventional chemotherapy group was 100% (30/30). The median sum of recurrence-free interval was 70.5 months (range: 19 to 330 months) in the sequential chemotherapy group and 15.0 months (range: 6 to 40 months) in the conventional chemotherapy group. Statistically significant differences were observed between the two groups for both recurrence rate and median recurrence-free interval (all P<0.01).In the sequential chemotherapy group, the median progression-free survival (PFS) time was 84.0 months (range: 34 to 373 months), and the median overall survival (OS) time was 87.0 months (range: 45 to 377 months). In contrast, in the conventional chemotherapy group, the median PFS time was 30.5 months (range: 14 to 60 months), and the median OS time was 37.5 months (range: 18 to 67 months). Statistically significant differences were observed between the two groups for both PFS and OS (all P<0.001). In the sequential chemotherapy group, the 3-year, 5-year, and 10-year OS rates were 100% (70/70), 93% (65/70), and 21% (15/70), respectively. In contrast, in the conventional chemotherapy group, the OS rates were 50% (15/30) at 3 years, 3% (1/30) at 5 years, and 0 at 10 years, respectively. The two groups were compared respectively, and the differences were statistically significant (all P<0.05). Conclusions: Sequential chemotherapy significantly prolongs PFS and OS in patients with ovarian epithelial carcinoma, fallopian tube carcinoma, and primary peritoneal carcinoma. The efficacy is superior to that of the conventional chemotherapy, with manageable adverse reactions. The use of sequential chemotherapy as first-line treatment for patients with ovarian epithelial carcinoma, fallopian tube carcinoma, and primary peritoneal carcinoma is recommended.

Predicting distribution of aeolian vibration amplitude of undamped overhead transmission lines

The most widely accepted estimation procedure of the severity of aeolian vibration is by calculating the maximum oscillation amplitudes of the conductor using Energy Balance Principle (EBP). However, the EBP is based on wind tunnel results where only one frequency is excited, while observations and experimental results show that multiple resonant modes are excited simultaneously. Furthermore, the required number of cycles of each amplitude level is not provided by current EBP-based methods. In this paper, vibration data from an experimental undamped ACSR Bersfort test line in Quebec, Canada, is recorded and analyzed. For each record of aeolian vibrations, amplitudes are fitted to a Rayleigh distribution based on the narrow-band assumption. The number of cycles and Rayleigh parameter are then related to wind conditions through a modified Strouhal frequency and EBP methodology. A statistical model is proposed to relate vibration profiles and wind input while considering wind turbulence intensity. The proposed method performs well and gives accurate estimates of both vibration amplitudes and number of cycles for ACSR Bersfort conductor. Physical and statistical theory is provided for each step of the method in order to extend the application of the method to other types of conductors or different line configurations.

The effects of 3D printing designs on PLA polymer flexural and fatigue strength

This study assessed the comprehensive assessment of flexural and fatigue strength of the three-dimensional (3D)-printed polylactic acid (PLA) samples across diverse printing designs and parameters. The experiment framework included a diverse array of printing parameters: layer heights, first layer thicknesses, infill densities, top/bottom infill patterns, extruder temperatures, perimeters, and types of solid layer top and bottom. Our findings suggest that there is an interplay between these parameters and the mechanical properties of PLA specimens. Notably, the fatigue strength of PLA printing specimens is more significantly influenced (0.44%) by an increase in the thickness of the first layer compared to flexural strength (87%). The rate of increase in bending strength is lower in cases of layer height (3.55%) and initial layer height (0.44%) in contrast with other factors. Specimens with an initial layer thickness of 0.4 mm reached the highest number of cycles until failure, recording 21 022 cycles. Furthermore, the study identifies the infill pattern’s impact on strength, highlighting that the line infill pattern type case has the highest bending strength of 75.97 MPa and surpasses the honeycomb pattern in bending strength. Compared to the Honeycomb pattern, the rectilinear design has 2.1% higher bending strength. The number of cycles to failure of the rectilinear pattern is greater than those of the honeycomb pattern. In comparison to other patterns, the Rectilinear Top/Bottom infill pattern has a higher interest rate of 27.5% for bending strength and 200.83% for fatigue strength. Additionally, greater bending and flexural strength are obtained by raising the solid layer top, bottom, and perimeter values, respectively. In comparison to the other temperatures, the bending strength and fatigue strength are highest at 200 °C. Therefore, the first layer height of 0.4 mm, the top/bottom rectilinear infill pattern, the extruder temperature of 200 °C, the perimeter value of 3, the solid layer/top value of 3, and the solid layer/bottom value of 3 are the optimal values for the part subjected to at the same time bending strength combined with fatigue strength. This comprehensive study may provide a broader and deeper understanding of individual and combined effects on an overview of the bending and fatigue strength in connection to printing design and printing parameters, as well as the ideal optimal parameters for 3D printing with the PLA material. Manufacturers and designers can use the recommended parameters to optimize the strength of their printed parts, considering both bending and fatigue performance.

Studies on the Evolution of Fatigue Strength of Aluminium Wires for Overhead Line Conductors

Traditional ACSR overhead wires, which consist of a high-strength steel core and several layers of aluminium wires, are currently the most popular overhead line conductor (OHL) design globally. Operating conditions, particularly operating under varying stresses from Karman vortices, lead to the fatigue cracking of wires of the outer layer, followed by wires of the inner layers. Karman vortices are formed by the detachment of a laminar wind stream flowing around the conductor, which causes vibrations in the conductor called wind or aeolian oscillations. Aluminium wires are manufactured using standard batch material drawing technology. Although the fatigue strength of such wires is not standardised, there are various criteria for evaluating this characteristic, as well as established limits on the number of cycles needed to break the first wires of the outer layer. Fatigue strength also strongly depends on the geometric structure of the wire and its operating conditions. The article analyses the influence of the mechanical condition of aluminium wires used in ACSR cables on their fatigue strength. We then present results from aluminium wire fatigue tests conducted on a specially constructed test rig. In addition, fatigue cracks were interpreted using scanning microscopy.

A Modified Perturbation Method for Global Dynamic analysis of Generalized Mixed Rayleigh–Liénard Oscillator with Cubic and Quintic Nonlinearities

Abstract Deriving analytical relationship between the system parameters and amplitude of the limit cycle is a meaningful and challenging task. Currently, numerous existing analytical approximate methods struggle to achieve this goal when expressions of restoring force or nonlinear damping is complicated. To overcome this shortcoming, this study proposes a modified generalized harmonic function perturbation method. Using the proposed method, a generalized mixed Rayleigh–Liénard oscillator with cubic and quintic nonlinearities was investigated. The analytical relationships between the system parameters and amplitude of the limit cycle, as well as the expression of its characteristic quantity, were derived. By employing these analytical relationships, the existence, stability, number, position, and amplitude of each limit cycle are quantitatively analysed. The homoclinic and heteroclinic bifurcations were also predicted using the above analytical relationships. Additionally, analytical approximate solutions for this oscillator were calculated using the proposed method. All results obtained in this study were subsequently confirmed numerically to demonstrate their feasibility and validity. Consequently, the proposed method can be considered an effective supplement to perturbation-based methods. This also implies that the work presented in this paper has a certain theoretical significance and application value in the research area of quantitative analysis methods for strongly nonlinear oscillators.

HeredERA Breast Cancer: a phase III, randomized, open-label study evaluating the efficacy and safety of giredestrant plus the fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injection in patients with previously untreated HER2-positive, estrogen receptor-positive locally advanced or metastatic breast cancer

BackgroundHER2-positive, estrogen receptor-positive breast cancer (HER2+, ER+ BC) is a distinct disease subtype associated with inferior response to chemotherapy plus HER2-targeted therapy compared with HER2+, ER-negative BC. Bi-directional crosstalk leads to cooperation of the HER2 and ER pathways that may drive treatment resistance; thus, simultaneous co-targeting may optimize treatment impact and survival outcomes in patients with HER2+, ER+ BC.First-line (1L) treatment for patients with HER2+ metastatic BC (mBC) is pertuzumab, trastuzumab, and taxane chemotherapy. In clinical practice, dual HER2 blockade plus a fixed number of chemotherapy cycles are given as induction therapy to maximize tumor response, with subsequent HER2-targeted maintenance treatment given as a more tolerable regimen for long-term disease control. For patients whose tumors co-express ER, maintenance endocrine therapy (ET) can be added, but uptake varies due to lack of data from randomized clinical trials investigating the superiority of maintenance ET plus dual HER2 blockade versus dual HER2 blockade alone. Giredestrant, a novel oral selective ER antagonist and degrader, shows promising clinical activity and manageable safety across phase I–II trials of patients with ER+, HER2-negative BC, with therapeutic potential in those with HER2 co-expression.MethodsThis phase III, randomized, open-label, two-arm study aims to recruit 812 patients with HER2+, ER+ locally advanced (LA)/mBC into the induction phase (fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injection [PH FDC SC] plus a taxane) to enable 730 patients to be randomized 1:1 to the maintenance phase (giredestrant plus PH FDC SC or PH FDC SC [plus optional ET]), stratified by disease site (visceral versus non-visceral), type of LA/metastatic presentation (de novo versus recurrent), best overall response to induction therapy (partial/complete response versus stable disease), and intent to give ET (yes versus no). The primary endpoint is investigator-assessed progression-free survival. Secondary endpoints include overall survival, objective response rate, clinical benefit rate, duration of response, safety, and patient-reported outcomes.DiscussionheredERA BC will address whether giredestrant plus dual HER2 blockade is superior to dual HER2 blockade alone, to inform the use of this combination in clinical practice for maintenance 1L treatment of patients with HER2+, ER+ LA/mBC.Trial registrationClinicalTrials.gov, NCT05296798; registered on March 25, 2022. Protocol version 3.0 (November 18, 2022). Sponsor: F. Hoffmann-La Roche Ltd, Grenzacherstrasse 124 4070, Basel, Switzerland.

Joint optimization of efficiency and volume for an inductor‐based battery balancing circuit

SummaryIn recent years, with the increase in the number of electric vehicles, the number of retired power batteries, which predominantly include lithium‐ion batteries, has surged. Recycling these retired power batteries can reduce environmental pollution and resource waste. However, the voltage of a single lithium‐ion battery is low, and multiple single batteries need to be connected in series to satisfy application requirements. This use of multiple batteries results in inconsistencies in battery cell parameters. As the number of series connections increases, this inconsistency problem becomes more prominent, and it can even decrease the system's capable number of charge and discharge cycles. Due to the wide voltage performances of lithium‐ion batteries, inductive balancing circuits are more suitable for balancing a series of lithium‐ion battery cells. This paper considers a single inductor balancing circuit and proposes a joint optimization of efficiency and volume. By flexibly allocating the weight coefficients of efficiency and volume, the algorithm can optimize the overall efficiency and volume of the hardware circuit according to different circuit design requirements. Finally, the effectiveness of the proposed joint optimization method is verified by building a laboratory prototype.

Preliminary implantation experience in Europe with a novel insertable cardiac monitor

Abstract Background The LUX-Dx is a new insertable cardiac monitor (ICM) available in the European market since October 2022. Purpose To describe the initial experience of LUX-Dx implantation in Europe and report feedbacks from operators and patients. Methods The system includes an incision tool and a single-piece insertion tool that is pre-loaded with the small (1.2 cm3) ICM. The implantation procedure is straightforward and comprises the incision, the creation of the device pocket, the insertion of the ICM, the verification of sensing and the incision closure. Following implantation, patients are provided with a mobile device preloaded with the App which connects to their ICM and transmits data daily, or as needed, to the management system. We analyzed data and feedbacks collected at 20 European centers at the time of implantation and before patient discharge. Results A total of 175 implantation procedures were performed in 20 European centers. The most frequent indications for ICM implantation were syncope (n = 119, 68%) and cryptogenic stroke (n=15, 9%). Most procedures (157, 90%) were performed in electrophysiology laboratories by expert operators. The procedure was performed under local anesthesia in 169 (97%) patients, and systemic or local antibiotics were used before the procedure in 96 (55%) cases. A surface ECG mapping was performed before 65 (37%) insertions. All ICMs were implanted in the left parasternal region, with an orientation of 45° in 159 (91%) patients. Device repositioning was required after verification of sensing in 6 (3%) patients. The ICM was successfully implanted in all patients and no procedural complications were reported; the median time from skin incision to suture was 4 min (25th-75th percentiles 2-7). The mean R-wave amplitude was 0.38±0.34 mV at implantation and 0.42±0.38 mV before patient discharge (on average after 1 day). The P-wave visibility, i.e., the ratio between the number of clearly identifiable P-waves and the number of heart cycles during 10 sec ECG with a regular 1:1 conduction, was 92±21% at implantation and 93±18% before discharge. Survey questions on the overall operator experience with the implantation procedure are reported in Figure 1 and those on the patient experience are reported in Figure 2. Conclusions Implantation of the LUX-Dx seems fast and uncomplicated; operator and patient feedbacks are positive. Post-implantation sensing values, i.e. R-wave sensing and P-wave visibility, are good.Figure 1Figure 2

Vapor/Vapor‐Solid Interfacial Growth of Covalent Organic Framework Membranes on Alumina Hollow Fiber for Advanced Molecular Separation

Covalent organic frameworks (COFs), known for their chemical stability and porous crystalline structure, hold promises as advanced separation membranes. However, fabricating high‐quality COF membranes, particularly on industrial‐preferred hollow fiber substrates, remains challenging. This study introduces a novel vapor/vapor‐solid (V/V‐S) method for growing ultrathin crystalline TpPa‐1 COF membranes on the inner lumen surface of alumina hollow fibers (TpPa‐1/Alumina). Through vapor‐phase monomer introduction onto polydopamine‐modified alumina at 170 °C and 1 atm, efficient polymerization and crystallization occur at the confined V‐S interface. This enables one‐step growth within 8 h, producing 100 nm thick COF membranes with strong substrate adhesion. TpPa‐1/Alumina exhibits exceptional stability and performance over 80 h in continuous cross‐flow organic solvent nanofiltration (OSN), with methanol permeance of about 200 L m‐2 h‐1 bar‐1 and dye rejection with molecular weight cutoff (MWCO) of approximately 700 Da. Moreover, the versatile V/V‐S method synthesizes two additional COF membranes (TpPa2Cl/Alumina and TpHz/Alumina) with different pore sizes and chemical environments. Adjusting the COF membrane thickness between 100‐500 nm is achievable easily by varying the growth cycle numbers. Notably, TpPa2Cl/Alumina demonstrates excellent OSN performance in separating the model active pharmaceutical ingredient glycyrrhizic acid (GA) from dimethyl sulfoxide (DMSO), highlighting the method’s potential for large‐scale industrial applications.

Vapor/Vapor-Solid Interfacial Growth of Covalent Organic Framework Membranes on Alumina Hollow Fiber for Advanced Molecular Separation.

Covalent organic frameworks (COFs), known for their chemical stability and porous crystalline structure, hold promises as advanced separation membranes. However, fabricating high-quality COF membranes, particularly on industrial-preferred hollow fiber substrates, remains challenging. This study introduces a novel vapor/vapor-solid (V/V-S) method for growing ultrathin crystalline TpPa-1 COF membranes on the inner lumen surface of alumina hollow fibers (TpPa-1/Alumina). Through vapor-phase monomer introduction onto polydopamine-modified alumina at 170 °C and 1 atm, efficient polymerization and crystallization occur at the confined V-S interface. This enables one-step growth within 8 h, producing 100 nm thick COF membranes with strong substrate adhesion. TpPa-1/Alumina exhibits exceptional stability and performance over 80 h in continuous cross-flow organic solvent nanofiltration (OSN), with methanol permeance of about 200 L m-2 h-1 bar-1 and dye rejection with molecular weight cutoff (MWCO) of approximately 700 Da. Moreover, the versatile V/V-S method synthesizes two additional COF membranes (TpPa2Cl/Alumina and TpHz/Alumina) with different pore sizes and chemical environments. Adjusting the COF membrane thickness between 100-500 nm is achievable easily by varying the growth cycle numbers. Notably, TpPa2Cl/Alumina demonstrates excellent OSN performance in separating the model active pharmaceutical ingredient glycyrrhizic acid (GA) from dimethyl sulfoxide (DMSO), highlighting the method's potential for large-scale industrial applications.

#2136 Hyponatremia as a presenting symptom of secondary adrenal insufficiency induced by immune checkpoint inhibitors

Abstract Background and Aims Endocrinopathies are common complication of treatment with immune checkpoint inhibitors (ICI). Adrenal axis may be affected through either direct adrenal toxicity leading to primary hypoadrenalism or due to pituitary dysfunction resulting in secondary adrenal insufficiency. Patients with secondary insufficiency may have variable presentation and, in some cases, initially present with hyponatremia only. This abstract reports a cohort of patients who developed hyponatremia as initial symptom of secondary adrenal insufficiency. Method After obtaining approval from the institutional review board, medical records of the nephrology service at a large cancer center were reviewed. Patient is well included in the study if they developed moderate (plasma Na &amp;lt;130 mEq/L) and severe (plasma Na &amp;lt;120 mEq/L) hyponatremia during treatment with ICI and met a biochemical criterion for adrenal insufficiency (morning serum cortisol level &amp;lt;3.0 mcg/dL). Results Nine patients who met the criteria were identified (Table 1). There were 5 males and four females. Mean age was 67.6 year. Median number of ICI therapy cycles was 10 but treatment number ranged from 2-84. For patient's would treat with combination of CTLA-4 and PD 1 inhibitors and 5 patients were treated with PD 1 inhibitor alone. Four patients had severe hyponatremia and five presented with moderate hyponatremia. All patients were normotensive on presentation. All patients had low morning cortisol level but only two patients had low ACTH level. All patients had low normal ACTH levels. One patient underwent ACTH stimulation test which was negative. Additionally for patient has had normal thyroid function. Eight patients underwent an MRI and 4 of them had evidence of possible pituitary inflammation. All patients were started on physiologic corticosteroid replacement with prompt resolution of hyponatremia. All patients required ongoing corticosteroid replacement therapy. Conclusion Secondary adrenal insufficiency in the setting of ICI toxicity can present with initial diagnosis of hyponatremia. Patients in this cohort were normotensive on presentation despite adrenal insufficiency and therefore required high index of suspicion for the diagnosis. Most patients in the study also had low normal ACTH levels however responded clinically to treatment with corticosteroid replacement indicating that adrenal sufficiency was the cause of hyponatremia. ACTH test may be falsely negative in these patients if adrenal insufficiency developed less than six weeks prior and adrenal atrophy did not occur yet.

Effect of simulated clinical use and sterilization on the cyclic fatigue resistance of nickel titanium files.

Assess the effect of simulated clinical use and sterilization on the cyclic fatigue resistance of Race Evo and Tia Tornado Blue nickel titanium (NiTi) files. For this study, a total of sixty-four NiTi files were selected, with thirty-two files each from two different manufacturers. Files from each manufacturer were subdivided into four subgroups (n=8) based on the test parameters. The control groups included files that were neither used nor sterilized. Files from the test groups were used to prepare the root canals of extracted mandibular premolars and then sterilized. This procedure was repeated once, twice, or thrice, depending on the test group. All files were then subjected to a cyclic fatigue test. Data was statistically analyzed using the Kruskal-Wallis and Mann-Whitney U tests. No significant difference was observed in the number of cycles to failure (NCF) among the subgroups for both types of files (P=0.869 for Tia Tornado Blue, P=0.626 for Race Evo). Tia Tornado Blue files displayed significantly higher NCF values in the control (P=0.021), once (P=0.027), and thrice (P=0.031) usage groups when compared to Race Evo files. Repeated clinical use and sterilization for up to three cycles did not affect the cyclic fatigue resistance of Race Evo and Tia Tornado Blue files.

Identification of structural defects and their impact on the magnetic memory, static and cyclic strength of VNS9-SH thin sheet trip-steel

Identification of microstructure defects, which are stress concentrators (SC) during the operation of mechanical engineering products, is an important scientific and practical task relevant for manufacturing enterprises. This problem becomes especially urgent and difficult for critical helicopter parts made of sheet TRIP steel VNS9-Sh (23Kh15N5AM3-Sh) and operating under cyclic loads due to the complex microstructure of the steel and small thickness of strips and sheets. To assess the impact of structural defects on the cyclic strength of products made of the steel under study, the specimens were preliminary sorted proceeding from the results of their testing using the method of metal magnetic memory (MMM) and metallographic studies. The MMM method is a structure-sensitive procedure which provides information about the presence of structural defects that arise during the manufacture. Magnetic anomalies in the form of sharp local changes in the intrinsic stray magnetic field (SSMF) (H) and its gradient |ΔH| along the length of the controlled section Δx, were identified on the surface of sheets cut from five different batches. A conventional classification of the identified anomalies was made according to the magnitude of the magnetic field gradient. The specimens of two types were cut in zones of magnetic anomalies and outside them: type 1 — for cyclic tests and type 2 — for metallographic studies. The geometric parameters and field gradient values of magnetic anomalies on specimens of type 1 and type 2 were the same. Metallographic studies in zones of maximum magnetic field gradient on type 2 specimens revealed defects in the form of a strip at the boundary of different structures, which is a structural stress concentrator (SSC) and a source of the inhomogeneity and changes in the magnetic properties. Type 1 specimens with similar magnetic anomalies and Type 1 specimens cut from sheets outside zones of magnetic anomalies were then selected for cyclic testing. Comparative tests for cyclic strength of the specimens with and without specified SSC were carried out. It is shown that the presence of SSC zones in the specimens reduces the number of cycles to failure during cyclic tests by 1 – 2 orders of magnitude compared to the specimens free of SSC. Based on cyclic tensile tests of specimens, a limiting value of the magnetic field gradient was determined that corresponds to the acceptable level of stress concentration on structural defects. This value is recommended for use as a rejection criterion when examining a new tape by the MMM method.