An Engineering Model of Magnetic Flux Density and Electromagnetic Force Density at the Structural Discontinuity within Transformer Cores

The structural discontinuities in the form of air gaps in transformer cores cause the concentration of electromagnetic force, which is an important source of transformer vibration and noise. In this paper, an engineering model of magnetic flux density and electromagnetic force density on transformer core discontinuities is analytically developed. Based on a reasonable structural simplification and assumptions, magnetic flux density and electromagnetic force density are deduced as explicit functions of the geometric, material, and electrical excitation characteristics of the gap region and the transformer core. The accuracy of the established model is validated by the finite element method (FEM) combined with a magnetic measurement experiment. According to this engineering model, the electromagnetic force density can be reduced by decreasing the gap ratio and increasing the gap thickness to a reasonable level. The outcome of this paper can help to understand the physical mechanism of the electromagnetic force generated by core air gap discontinuities, which is meaningful for noise control and the condition monitoring of transformers

Aminoalkyldisiloxane as effective electrolyte additive for improving high temperature cycle life of nickel-rich LiNi0.6Co0.2Mn0.2O2/graphite batteries

A novel aminoakyldisiloxane compound, (3-(N,N-dimethylamino)diethoxypropyl) pentamethyldisiloxane (DSON), is reported as an effective electrolyte additive for improving the electrochemical performances of high energy density power batteries of nickel-rich LiNi0.6Co0.2Mn0.2O2 (NCM622)/graphite. The NCM622/graphite cells using DSON addition in the carbonate-based reference electrolyte exhibit enhanced electrochemical performances, especially high temperature performances including long cycle life and high temperature storage. The pouch cell (1 Ah) with 0.2 wt% DSON retained a capacity of 88% as compared with 84% for that without DSON in electrolyte after 200 cycles at 45 degrees C. The mechanism investigation reveals that DSON acts as a film-forming additive for constructing uniform conductive cathode electrolyte interphase (CEI) layer upon NCM622 particles, which suppresses the internal cracks and prohibits the irreversible phase transformation of NCM622. DSON also serves as an effective water/acid scavenger and inhibits the hydrolysis of LiPF6, thus effectively blocking the occurrence of side reactions and the dissolution of transition metal ions from cathode. Therefore, NCM622 cathode sheet maintains a better integrity surface morphology after 100 cycles. This work demonstrates that aminoakyldisiloxane is promising for practical use as effective electrolyte additive for high energy density power batteries of nickel-rich NCM/graphite

The Spatio-Temporal Pattern and Transition Mode of Recessive Cultivated Land Use Morphology in the Huaibei Region of the Jiangsu Province

Examining land use transition is a new way of building on the comprehensive research on Land Use/Cover Change (LUCC). Research on transition law and characteristics is important for improving the theory of land use transition and the practice of land resource management, and for being able to provide a basis and reference for promoting socio-economic transformation. Based on the relevant statistical data concerning cultivated land use in the Huaibei area of the Jiangsu Province from 1995 to 2020, and by understanding the county as a unit to be measured, this paper constructed a multi-dimensional (economic–social–ecological) functional index system of recessive morphology, analyzed the spatio-temporal pattern of the transition of cultivated land use, identified transition point mutations, and established the transition mode by adopting multi-dimensional time series point mutation detection and the piecewise linear regression method. The findings suggest that the index of recessive cultivated land use morphology in the Huaibei region of the Jiangsu Province presents a trend of “slow decline to significant growth to stable growth”. Moreover, the index presented evolutionary characteristics such as “high in the middle and east while low in the west”, as well as “the relatively balanced distribution between counties”, thus indicating that the degree of transition deepened, it showed a homogeneous development trend, and the transition process presented obvious “ladder” stage characteristics; therefore, the authors suggest making scientific use of cultivated land resources, in accordance with local conditions, in order to make the land use transition of cultivated land efficient, green, and sustainable

Distributed Magnetic Flux Density on the Cross-Section of a Transformer Core

In this paper, the magnetic flux density distribution on the cross-sections of a transformer core is studied. The core for this study consists of two identical U-shaped cores joint at their open surfaces with known air gaps. The magnetic flux density at one of their joint boundary surfaces was measured for different air gaps. A finite element model (FEM) was built to simulate the magnetic flux density and compared with experiment data. Using the validated FEM, the distributed magnetic flux density on the cross-section of the core structure can be obtained when the air gap approaches zero. An engineering model of the density based on the Ampere’s circuit law was also developed and used to explain the relationship between air gap and mean magnetic flux density on the cross-section. The magnetic flux density on the cross-section was found to have a convex-shaped distribution and could be described by an empirical formula. Using this approach, the magnetic flux density distribution in cores with different interlayer insulation was obtained and discussed. This method could also examine the leakage of magnetic flux density in the air gap region when the distance is non-zero, and the relationship between the leakage field and the field in the core structure. The proposed method and model can provide a more detailed understanding for the magnetic field of transformer cores and potential application in designing quiet transformers and condition monitoring

Partnered Excited-State Intermolecular Proton Transfer Fluorescence (P-ESIPT) Signaling for Nitrate Sensing and High-Resolution Cell-Imaging

Nitrite (NO2−) is a common pollutant and is widely present in the environment and in human bodies. The development of a rapid and accurate method for NO2− detection is always a very important task. Herein, we synthesized a partnered excited-state intermolecular proton transfer (ESIPT) fluorophore using the “multi-component one pot” method, and used this as a probe (ESIPT-F) for sensing NO2−. ESIPT-F exhibited bimodal emission in different solvents because of the solvent-mediated ESIPT reaction. The addition of NO2− caused an obvious change in colors and tautomeric fluorescence due to the graft of NO2− into the ESIPT-F molecules. From this basis, highly sensitive and selective analysis of NO2− was developed using tautomeric emission signaling, achieving sensitive detection of NO2− in the concentration range of 0~45 mM with a detection limit of 12.5 nM. More importantly, ESIPT-F showed the ability to anchor proteins and resulted in a recognition-driven “on-off” ESIPT process, enabling it to become a powerful tool for fluorescence imaging of proteins or protein-based subcellular organelles. MTT experimental results revealed that ESIPT-F is low cytotoxic and has good membrane permeability to cells. Thus, ESIPT-F was further employed to image the tunneling nanotube in vitro HEC-1A cells, displaying high-resolution performance

A Solvent-Mediated Excited-State Intermolecular Proton Transfer Fluorescent Probe for Fe3+ Sensing and Cell Imaging

Constructing excited-state intermolecular proton transfer (ESIPT-e) fluorophores represents significant challenges due to the harsh requirement of bearing a proton donor-acceptor (D-A) system and their matching proton donating-accepting ability in the same molecule. Herein, we synthesized a new-type ESIPT-e fluorophor (2-APC) using the “four-component one-pot” reaction. By the installing of a cyano-group on pyridine scaffold, the proton donating ability of -NH2 was greatly enhanced, enabling 2-APC to undergo ESIPT-e process. Surprisingly, 2-APC exhibited dual-emissions in protic solvents ethanol and normal fluorescence in aprotic solvents, which is vastly different from that of conventional ESIPT-a dyes. The ESIPT emission can be obviously suppressed by Fe3+ due to the coordination reaction of Fe3+ with the A-D system in 2-APC. From this basis, a highly sensitive and selective method was established using 2-APC as a fluorescent probe, which offers the sensitive detection of Fe3+ ranging from 0 to 13 μM with the detection limit of 7.5 nM. The recovery study of spiked Fe3+ measured by the probe showed satisfactory results (97.2103.4%) with the reasonable RSD ranging from 3.1 to 3.8%. Moreover, 2-APC can also exhibit aggregation-induced effect in poor solvent or solid-state, eliciting strong red fluorescence. 2-APC was also applied to cell-imaging, exhibiting good cell-permeability, biocompatibility and color rendering. This multi-mode emission of 2-APC is significant departure from that of conventional extended p-conjugated systems and ESIPT dyes based on a flat and rigid molecular design. The “one-pot synthesis” strategy for the construction of ESIPT molecules pioneered a new route to achieve tricolor-emissive fluorophores

The skin prick test response after allergen immunotherapy in different levels of tIgE children with mite sensitive Asthma/Rhinitis in South China

Background: At present, the biomarkers which can predict the clinical efficacy of allergen immunotherapy (AIT) are still much debated. IgE levels are often related to allergic severity. Therefore, this study aimed at relating total IgE (tIgE) levels with the efficacy of AIT assessed by symptoms and drug score and skin prick test (SPT) response. Methods: We evaluated 81 allergic children who had received house-dust mite (HDM) subcutaneous immunotherapy for three years. According to the tIgE levels before treatment, all children were divided into high value, medium value and low value group. Each group according to sIgE/tIgE ratio was divided into subgroups. The efficacy of AIT is assessed by symptoms and drug score. By comparing changes in the grade of SPT in each group, the response of AIT are evaluated. Results: The SPT grade changes to determine efficacy had a high degree of consistency with symptoms and drug score judgment (sensitivity 89.7%, specificity 78.3%, Kappa = 0.670, P < 0.001). Compared to ineffective cases, the effective cases had lower tIgE (P < 0.001) and higher ratio of sIgE/tIgE (P < 0.001). The grades of SPT declined the most in the low value group (low value group vs. medium value group, P < 0.05; low value group vs. high value group, P < 0.001; medium value group vs. high value group, P < 0.05). Conclusions: The SPT grade change can be used for efficacy evaluation. Children with lower level of tIgE and higher ratio of sIgE/tIgE that obtain a more satisfactory effect

Efficacy and safety of canakinumab in systemic juvenile idiopathic arthritis, the first Chinese experience

Abstract Background Systemic juvenile idiopathic arthritis (sJIA) is a severe form of juvenile arthritis that is characterized by chronic joint inflammation and systemic symptoms such as fever, rash, and organ involvement. Anti-IL-6 receptor monoclonal antibody tocilizumab is an effective treatment. However, some patients still experience persisting or recurrent symptoms and the real-world effectiveness of canakinumab in Chinese patients with sJIA has never been reported. Therefore, this study aimed to assess the efficacy and safety of canakinumab in Chinese patients with sJIA using real-world data. Methods We conducted a retrospective study on children with active sJIA. Clinical features, laboratory data, corticosteroid dosage, and adverse events (AEs) were collected at baseline and at 4, 8, 12, and 24 weeks after initiating canakinumab treatment. Results Seven female and four male patients were included in the study. All patients had previously been treated with tocilizumab and were administered canakinumab for 12.4 ± 3.4 months. Notably, significant improvements were observed in both clinical signs and symptoms as well as laboratory indicators. Four children under corticosteroid treatment were able to successfully discontinue their corticosteroid therapy: one at week 4, two at week 12, and one at week 24. Notably, there was a significant reduction in the number of tender and swollen joints (P = 0.0059) as well as the systemic juvenile arthritis disease activity score (P < 0.0001). The most common AE was infection, but no patients experienced serious AEs. No cases of macrophage activation syndrome or death were reported during the follow-up period. Conclusions Canakinumab was found to be potentially efficacious and safe in Chinese patients with sJIA. No new AEs were observed with canakinumab treatment

Real-world safety profile of the 9-valent human papillomavirus vaccine: A study in Zhejiang, China from 2019 to 2021

The safety profile of the 9-valent human papillomavirus vaccine (9vHPV) was evaluated based on the reporting rate of adverse events following immunization (AEFI) obtained from the passive surveillance data in Zhejiang. The 9vHPV AEFI reports in Zhejiang were collected and reviewed from the National Adverse Event Following Immunization Surveillance System (NAEFISS) from 2019 to 2021. Reporting rates of AEFI were analyzed under multiple aspects, including age, city, number of vaccinations, AEFI categories, and diagnosis categories. This study used the reporting odds ratio (ROR) for anomalous signal assessment. The NAEFISS collected 331 AEFI reports after administering 1,064,851 doses of 9vHPV, with a crude AEFI rate of 3.12/10,000 doses. The third dose had the highest reporting rate of minor vaccine-related reaction (n = 80, 3.06 per 10,000), followed by the first dose (n = 134, 2.98 per 10,000), and second dose (n = 76, 2.15 per 10,000). Fever/redness/induration was the most common minor adverse event (281 records, 2.64/10,000 doses). Nine cases of urticaria, ten cases of allergic rash, and ten cases of syncope were recorded. This study found a positive signal association between 9vHPV immunization and adverse events such as syncope, encephalitis, sterile abscess, and urticaria. This study did not identify any new emerging safety concerns. In the future, more research is needed to validate and further explore adverse reactions associated with 9vHPV

Research progress on classical traditional Chinese medicine formula Baihe Zhimu (Lilium lancifolium bulb and Anemarrhena asphodeloides rhizome) decoction in the treatment of depression

Depression is considered to be an “emotional disease” in ancient books of traditional Chinese medicine. Its clinical features are similar to those of “Lily disease” in the ancient Chinese medicine book Synopsis of the Golden Chamber written by Zhang Zhongjing in the Han Dynasty. Baihe Zhimu (Lilium lancifolium bulb and Anemarrhena asphodeloides rhizome) decoction (LBRAD) is the first prescription of “Lily Disease” in this book. It is also a special remedy for “Lily disease” after sweating. The classic recipe LBRAD consists of two herbs, fresh lily bulbs and dried Rhizoma Anemarrhena slice. It has the effect of supplementing nutrition and clearing heat, nourishing Yin and moistening. After more than two thousand years of clinical practice, it has been currently widely used in clinical treatment of depression. In this paper, the relationship between LBRAD and depression was systematically reviewed from both clinical and experimental studies, as well as the preparation, the clinical application, the pharmacological mechanism and the effective material basis for the treating depression of LBRAD. The core targets and biological processes of the depression treatment were explored through network pharmacological analysis, so as to speculate its potential mechanism. Finally, the association between LBRAD and post-COVID-19 depression was discussed. We concluded with a summary and future prospects. This review may provide a theoretical basis for the expansion of the clinical application of LBRAD and the development of new drugs for the treatment of depression, as well as new ideas for the secondary development of classical prescriptions