bluuebunny/crossref_metadata_2025 huggingface dataset:
AERODYNAMIC AND STRENGTH IMPROVEMENT OF THE AXIAL TURBINE OF A HELICOPTER GTE
Authors:   Samara National Research University, Popov G.М. , Goriachkin Evgenii S. ,   Samara National Research University, Baturin Oleg V. ,   Samara National Research University, Korneeva A.I. ,   Samara National Research University, Egorov Igor ,   Moscow Aviation Institute National Research University
Published: October 2022

The paper presents the results of solving the complex problem of improving strength and efficiency of a single-stage axial turbine of a small-sized helicopter GTE using multidisciplinary optimization methods. An analysis of the initial turbine showed that the strength reserve of the working blade was significantly lower than that required by the strength standards. In order to eliminate the problem at the first stage the task of rotor wheel adjustment only according to strength requirements without taking into account aerodynamic processes was solved. As a result, the turbine rotor wheel variants that met the strength limitations were obtained. These results were the starting point for aerodynamic optimization. The optimisation has resulted in a compressor turbine variant that meets the strength standards with an efficiency close to the initial compressor turbine variant.
CALCULATING THE PARAMETERS OF A GAS TURBINE ENGINE TAKING INTO ACCOUNT THE UNCERTAINTY OF THE INITIAL DATA
Authors:   Samara National Research University, Baturin Oleg V. , Nicolalde Paúl , Popov Grigorii M. , Matveev Valery. N. , Novikova Yulia. D.
Published: October 2022

The paper describes a method developed by the authors that allows the stochastic distribution of output parameters to be determined from known probability distributions of uncertain initial data by means of a mathematical model of the engine. It was found that the number of calls to the mathematical model is such that the calculation taking 7-8 uncertain variables into account, even with simple mathematical models, takes a huge amount of time. For this reason, a method was developed to obtain reliable stochastic results with a reduced number of uncertain initial data taken into account, based on sensitivity analysis. The calculated stochastic results were compared with experimental data. It was shown that the difference between the stochastic results of the calculation and the experiment represents a scattering bell (bivariate distribution) and can be described by 4 numerical criteria.
Conjugate Flow and Heat Transfer Mechanism between the Rib Cooling and Film Cooling
Authors:   State Key Laboratory for Strength and Vibration of Mechanical Structures Shaanxi Key Laboratory of Environment and Control for Flight Vehicle School of Aerospace, Xi'an Jiaotong University, Wei Jin Wei Jin , Shaoen Peng Shaoen Peng ,   State Key Laboratory for Strength and Vibration of Mechanical Structures Shaanxi Key Laboratory of Environment and Control for Flight Vehicle School of Aerospace, Xi'an Jiaotong University, Junmei Wu Junmei Wu ,   State Key Laboratory for Strength and Vibration of Mechanical Structures Shaanxi Key Laboratory of Environment and Control for Flight Vehicle School of Aerospace, Xi'an Jiaotong University, Jiang Lei Jiang Lei ,   State Key Laboratory for Strength and Vibration of Mechanical Structures Shaanxi Key Laboratory of Environment and Control for Flight Vehicle School of Aerospace, Xi'an Jiaotong University, Wentao Ji Wentao Ji ,   Key Laboratory of Thermo- Fluid Science and Engineering of MOE School of Energy and Power Engieering, Xi'an Jiaotong University
Published: October 2022

Rib cooling and film cooling are the effective cooling schemes to meet the increasing demands of rising turbine inlet temperatures in modern gas turbine engines. Most studies have been carried out to find the flow and heat transfer characteristic of rib cooling or film cooling individually. While the conjugate heat transfer between these two cooling methods is rarely studied in the literature. In order to evaluate the interplay between the rib cooling and film cooling, the conjugate flow and heat transfer mechanism in two perpendicular flat plate channels connected by a conductive solid wall with a compound film hole through it is studied numerically. Ribs are arranged in the internal cooling channel and the heat conduction in the connecting wall and ribs are considered. The blowing ratios vary from 0.75 to 1.5. SST κ-ω and large-eddy simulation (LES) turbulence model are checked to find the applicability of the turbulence models in this simulation by comparing the numerically predicted results with the experimental results from literature. The results indicate that LES is better at capturing the fine structure of the flow field and has higher accuracy. The arrangement of film hole strengthens the heat transfer capacity of the internal cooling channel. However, the arrangement of ribs reduces the overall cooling efficiency of the mainstream cooling channel.
Effects of Partial Suction Side Rim on the Aerodynamics and Heat Transfer Cooling Performance of the Turbine Blade Squealer Tip
Authors:   Institute of Turbomachinery, Xi’an Jiaotong University, XU Chengtian , LI Zhigang ,   Institute of Turbomachinery, Xi’an Jiaotong University, LI Jun ,   Institute of Turbomachinery, Xi’an Jiaotong University, SONG Liming ,   Institute of Turbomachinery, Xi’an Jiaotong University
Published: October 2022

The effects of the partial suction side rim on the aerodynamics and heat transfer cooling performance of the turbine blade squealer tip using three-dimensional Reynold-Average Navier-Stokes (RANS) equations and standard k   turbulence model were investigated. The numerical heat transfer coefficient of the turbine blade with the flat tip was well agreed with the experimental data. The accuracy of the employed numerical method was validated. The leakage flow pattern, heat transfer coefficient and film cooling effectiveness of the intact rim tip with 1% of blade height tip clearance and 2% of blade height cavity depth for two tip film cooling layouts, at the blow ratio of 0.95, were compared and analysed. The results show that the total pressure loss of Layout 2 with film holes assigned near the cavity pressure side is larger than Layout 1 with film holes arranged along the cavity bottom camber line, but Layout 2 has a better tip cooling effect and validly reduce the tip thermal load. Five partial suction side rim tips were designed based on the full rim tip; it is found that Case 7, 10% of suction side rim is removed, has the best comprehensive aerodynamics and heat transfer cooling performance, compared to Case 2, the averaged total pressure loss coefficient drops by 6.6%, the averaged heat transfer coefficient only increases by 0.85% and the averaged film cooling effectiveness increases by 2.9%. The present work provides a reference to the high efficiency film cooling layout and rim structure design for the turbine blade squealer tip.
AN AERODYNAMIC PERFORMANCE OPTIMIZATION METHOD APPLIED TO THE INTAKE GRILLE OF ACTIVE CLEARANCE CONTROL SYSTEM
Authors:   School of Mechanical Engineering, Shanghai Jiaotong University, Zhang Shuyi , Yang Bo ,   School of Mechanical Engineering, Shanghai Jiaotong University, Xie Hong ,   School of Mechanical Engineering, Shanghai Jiaotong University, Zhu Guoming ,   School of Mechanical Engineering, Shanghai Jiaotong University, Song Moru ,   School of Mechanical Engineering, Shanghai Jiaotong University
Published: October 2022

The active clearance control system (ACC) of turbine is one of the core components,which can reduce the fuel consumption of civil aero-engine. And the tip-clearance change is greatly affected by the aerodynmaic performance of intake grille. To improve the performance, in this work, an aerodynamic optimization method of intake grille is proposed. This method is divided into three parts, such as the parameterization, the fitness evaluation and the optimization algorithm. Based on the commercial software NX 12.0, the grille is parameterized according to seven key geometric parameters. In order to evaluate the aerodynamic performance of grille accurately, a special fitness function is presented and figured out with the help of an adaptive back-propagation multi-layer feedforward artificial neural network (BP-MLANN). Lastly, utilizing the continuous swarm particle optimization-modified very fast simulated annealing algorithm (CPSO-MVFSA), the optimal aerodynamic performance of intake grille is achieved. Through analyzing the aerodynamic experiments and the computational fluid dynamic (CFD) simulation of intake grille, it is found that the aerodynamic performance of the optimized grille is better than that of the original. Therefore, this aerodynamic optimization method is feasible to improve the aerodynamic performance of intake grille.
SURROGATE-BASED AERODYNAMIC SHAPE OPTIMIZATION OF CONTRA ROTATING OPEN ROTOR
Authors:   Northwestern Polytechnical University, Wang Qihang , Zhou Li ,   Northwestern Polytechnical University, Wang Zhanxue ,   Northwestern Polytechnical University
Published: October 2022

In this paper, the study on aerodynamic shape optimization of contra rotating open rotor is presented. Computational fluid dynamics simulations combined with Neural networks (radial basis function) surrogate model is applied to solve the problem. The difficulty is associated with both time-consuming computational fluid dynamics simulations and the large number of design variables involved. The contra rotating open rotor optimization problem is to find the variables that produces the maximum propulsive efficiency for a limited range of thrust requirement. The DOE (deign of experiment) process is completed by uniform design and computational fluid dynamics simulations. The non-linear programming by quadratic lagrangian (NLPQL) is used to tackle the optimization problem. Infill sampling criteria is used in this process to reduce demand on the number of initial samples while keep the accuracy of surrogate model. After building the initial surrogate from DOE sampling, the update point is selected according to the infill sampling criteria. It shows that the infill sampling criteria is helpful in surrogate model building process and surrogate-based optimization method is valid for aerodynamic shape optimization of contra rotating open rotor.
A critical exposition of Bergson's process philosophy
Authors: Asuquo Godwin Okon , Umotong Iniobong D. , Dennis Otto
Published: October 2022

This paper is a critical and expository study of the basic ideas in the process thought of Henri Bergson. Process philosophy is one of the oldest traditions in metaphysics, traceable to the doctrine of Heraclitus, an ancient Greek thinker. It is opposed to the idea of the Milesian thinkers like Thales and Anaximenes, who believed that reality consists of an unchanging substance that persists. Overtime, the view that reality is a novelty and, as such creative became a discourse of interest, either implicitly or explicitly, for many philosophers in the different epochs of western philosophy. As a result, different ideas emerged in an attempt to explain processes. However, these ideas have been discovered to point toward two directions – mechanism and finalism. As against this stance which pointed toward an end to the creative and novel posture of reality, Henri Bergson came up with his philosophy of multiple virtualities. However, how successful was his project? In this paper, therefore, we critically assess some strengths and weaknesses of the basic ideas in his thought process. However, though we have noted some inherent problems in his thought, Bergson’s idea of reality as multiple virtualities gives room to reality as continually processual, overcoming the mechanistic or finalistic you of other thinkers.
Teachers' perceptions of online challenges in Junior Secondary Schools teachers in South Sulawesi, Indonesia
Authors: Asfah Indrawaty , Rahman Muhammad Asfah , Fitriyani Fitriyani
Published: October 2022

Since the suspension of all types of face-to-face activities during the pandemic, colleges, secondary schools, and elementary schools have adopted the strategy of online education. As a result, teachers and students have used online teaching and learning on an unprecedented scale. Online learning or e-learning has been assumed to be a significant tool for effectively continuing the teaching-learning process during the lockdown. Teachers and students have had to quickly alter their teaching and learning strategies, regardless of whether they were experienced in and prepared for online education, an environment with electronic devices and online applications. Despite the innumerable potentials and benefits of online learning, such as cost-effectiveness, promoting self-paced learning, better retention, and catering to learners' needs, teachers may not readily make the most and get the full benefits of online learning. Some studies have shown that learning achievement in online learning is lower than in traditional face-to-face learning. The present study explores the teachers' perception of the use of digital technology in their online instruction and challenges or problems they face when implementing online learning instruction. Besides, this study will discuss the teachers' measures to respond to and cope with the problems.
PENGEMBANGAN MEDIA PEMBELAJARAN MATEMATIKA BERBASIS MOBILE GAME APLIKASI CONSTRUCT 2 MATERI ARITMETIKA SOSIAL
Authors: Wiyanto Agus , Khabibah Siti
Published: October 2022

Pendidikan merupakan kebutuhan pokok manusia. Hal ini dikarenakan dalam pendidikan setiap individu akan melakukan proses pembelajaran untuk memperkaya pengetahuan, membentuk kepribadian serta pengembangan keterampilan baik jasmani maupun rohani. Penelitian ini diawali dengan melakukan wawancara kepada salah satu guru mata pelajaran matematika di MTs Darul Ulum Sumber Penganten Jogoroto. Wawancara bertujuan untuk mencari informasi tentang masalah yang berkaitan dengan pembelajaran matematika. Tujuan penelitian ini adalah untuk mendeskripsikan hasil pengembangan media pembelajaran ular tangga matematika pada materi bangun ruang sisi lengkung kelas IX yang meliputi aspek kevalidan, kepraktisan, dan keefektifan. Jenis penelitian ini adalah Research and Development model Borg and Gall yang terdiri dari tujuh tahapan. Subjek uji coba yang digunakan adalah kelas IX – C yang berjumlah 17 siswa. Penelitian yang dikembangkan dinyatakan memiliki kualitas baik dengan hasil berikut: 1) Valid dengan skor 3,43; 2) Praktis dengan rata-rata skor 3,68; dan 3) Efektif dengan ketuntasan klasikal sebesar 82,35%.
PENGARUH KECERDASAN EMOSIONAL TERHADAP KEMAMPUAN PEMAHAMAN KONSEP MATEMATIKA KELAS VII MTS FISABILILLAH
Authors: Farah Sadidah Achmad  , Fauzi Mulyatna
Published: October 2022

The purpose of this study was to determine how much influence emotional intelligence had on the ability to understand mathematical concepts of grade VII A and VII B students at MTs Fisabilillah School. The instrument in this study used an essay test of five questions and an emotional intelligence questionnaire of 40 statements. Based on the data that has been obtained from the calculation of the effect of emotional intelligence on the ability to understand mathematical concepts of MTs Fisabilillah School students, the researchers can conclude several things including, there is a significant influence on the influence of emotional intelligence on the ability to understand mathematical concepts of MTs Fisabilillah School students of 0.8359 or 69,87%. The rest is influenced by other factors, such as students' thinking ability, and other aspects not examined by this study. This is also reinforced by the results of hypothesis testing which shows that thitung > ttabel is thitung 11.1778 > ttabel= 2.00488 which states that there is a significant influence between emotional intelligence and the ability to understand mathematical concepts.
The Unconscious with Bond and Lacan: Definition by Deviation
Authors: Holmberg Rafael
Published: October 2022

This article argues that the paradox of James Bond's character (that he accords with the idea he represents precisely by deviating from it) is central to a Lacanian understanding of the unconscious (which is considered as a form of disjunctive synthesis - a logical operation which allows conflicting realities to coexist) This requires a review both of various Bond-moments as well as the role of the Real and Symbolic in the Lacanian unconscious.
Coexistence of Papillary Microcarcinoma and Hurthle Cell Adenoma: a Case of Thyroid Collision Tumor
Authors: TAŞCI Halil İbrahim , ERİNANC Hilal , TURK Emin , KARAGÜLLE Erdal
Published: October 2022

While thyroid cancers are usually present one type of cancer in the thyroid gland, rarely different thyroid cancers may found in one or two different lobes of the thyroid gland at the same time. A 70-years-old female patient presented with a long-standing neck swelling, especially on the left side, which was more prominent, recently increasing in size and causing shortness of breath. Due to tracheal compression and diagnosis of multi-nodular goiter, total thyroidectomy was performed. Histopathological examination revealed a thyroid collision tumor with papillary microcarcinoma on the right and hurtle cell adenoma on the left side. Due to its rarity, clinicians encountered difficulties in the diagnosis and treatment of thyroid collision tumors. We believe that to be aware of these rare entities by encouraging clinicians to report such cases enable to more solid conclusions to diagnosis and management of collision tumors.
Mini-review of interesting properties in Mn2CoAl bulk and films
Authors: Yang Ying
Published: October 2022

Heusler compounds exhibit many interesting properties, such as high thermopower, magnetocaloric properties, and even topological insulator states. Heusler Mn2CoAl alloy has been experimentally and theoretically proposed as a promising spin-gapless semiconductor with novel electronic, magnetic, spintronic, transport, and topological properties. Furthermore, the spin-gapless semiconducting-like behaviors are also predicted in Mn2CoAl films by measuring the transport and magnetic properties. This mini-review systematically summarizes the interesting properties of Mn2CoAl bulk and Mn2CoAl-based films. This mini-review is hoped to guide further experimental investigations and applications in the particular scientific community.
Development of multiplex cross displacement amplification combined with lateral flow biosensor assay for detection of virulent shigella sonnei
Authors: Wang Yonglu , He Ziqiang , Ablimit Patigul , Ji Shunshi , Jin Dong
Published: October 2022

Shigella sonnei is the most common Shigella spp. in developed areas and the second most common in undeveloped regions. In this study, a multiple cross displacement amplification (MCDA) assay was used in combination with a lateral flow biosensor (LFB) assay to detect virulent S. sonnei strains containing the ipaH and wbgX genes. The multiplex MCDA-LFB assay detected wbgX at ≥1 pg/μL and ipaH at ≥10 fg/μL within 30 min in pure cultures maintained at 63°C. This assay was sensitive for ~37 CFU of virulent S. sonnei and ~3.7 CFU of Shigella spp. and enteroinvasive E. coli in stimulated fecal samples and had 100% specificity among 59 reference strains. The MCDA-LFB assay was also able to differentiate between virulent S. sonnei and other Shigella spp. and enteroinvasive E. coli among 99 clinical isolates. In summary, a multiplex MCDA-LFB assay was developed for rapid, convenient, point-of-care, and accurate identification of virulent S. sonnei within 30 min and at a constant temperature without the need for expensive lab equipment.
A before-after-control-impact study of wildlife fencing along a highway in the Canadian Rocky Mountains
Authors: Ford Adam T. , Dorsey Benjamin , Lee Tracy S. , Clevenger Anthony P.
Published: October 2022

Wildlife exclusion fencing has become a standard component of highway mitigation systems designed to reduce collisions with large mammals. Past work on the effectiveness of exclusion fencing has relied heavily on control–impact (i.e., space-for-time substitutions) and before–after study designs. These designs limit inference and may confound the effectiveness of mitigation with co-occurring process that also changes the rate of collisions. We used a replicated (n = 2 sites monitored for over 1000 km years combined) before-after-control-impact study design to assess fencing effectiveness along the Trans-Canada Highway in the Rocky Mountains of Canada. We found that collisions declined for common ungulates species (elk, mule deer, and white-tailed deer) by up to 96% but not for large carnivores. The weak response of carnivores is likely due to the combination of fence intrusions and low sample sizes. We calculated realized fencing effectiveness by applying the same change in collision rates observed at control (unfenced) sites as the expected change for adjacent fenced sections. Compared with the apparent fencing effectiveness (i.e., the difference in WVCs rates before and after fencing was installed), the realized estimates of fencing effectiveness declined by 6% at one site and increased by 10% at another site. When factoring in the cost of ungulate collisions to society, fencing provided a net economic gain within 1 year of construction. Over a 10-year period, fencing would provide a net economic gain of > $500,000 per km in reduced collisions. Our study highlights the benefits of long-term monitoring of road mitigation projects and provides evidence of fencing effectiveness for reducing wildlife–vehicle collisions involving large mammals.
Cryoballoon catheter ablation or drug therapy to delay progression of atrial fibrillation: A single-center randomized trial
Authors: Ding Jun , Cheng Aijuan , Li Peng , Yan Yingchuan , Shi Yutian , Xue Zuochen , Sun Shan , Xu Jing
Published: October 2022

Background

Delaying atrial fibrillation (AF) progression is a key goal in cardiovascular treatment. However, numbers of previously published studies on delayed AF progression are relatively limited. The purpose of this study was to determine whether a cryoballoon catheter ablation (CA) strategy could delay AF progression compared to anti-arrhythmic drug (AAD) treatment in patients with paroxysmal AF.

Methods

A total of 204 subjects were enrolled in the trial, including 102 in the cryoballoon CA group and 102 in the AAD group. Participants were followed up with for 36 months. The primary study endpoint was the first occurrence of persistent atrial tachyarrhythmia, while secondary endpoints included the event rates of persistent atrial tachyarrhythmia at 1 and 2 years. The primary safety endpoint was serious adverse events.

Results

Overall, the 36-month follow-up was completed by 154 subjects (75.5%). At 3 years, documented progression from paroxysmal AF to persistent atrial tachyarrhythmia had occurred in 2 of the 102 patients assigned to undergo cryoballoon CA [2.203% (95% confidence interval (CI), 0.554–8.537)] and in 17 of the 102 patients assigned to receive AADs [20.223% (95% CI, 13.040–30.604)] [hazard ratio (HR), 0.107; 95% CI, 0.043–0.262; P < 0.001]. Lower rates of progression in the cryoballoon CA group compared to the AAD group were already obvious at 1 year [1.053% (95% CI, 0.149–7.238) vs. 5.284% (95% CI, 2.233–12.237)] [HR, 0.193; (95% CI, 0.039–0.956; P = 0.09)] and 2 years [2.203% (95% CI, 0.554–8.537) vs. 12.430% (95% CI, 7.066–21.371)] (HR, 0.169; 95% CI, 0.057–0.501, P < 0.001). Serious adverse events occurred in 7 of the 102 patients (6.9%) in the cryoballoon CA group and 9 of the 102 patients (8.8%) in the AAD group.

Conclusion

Cryoballoon CA was superior to AAD therapy in preventing the occurrence of persistent atrial tachyarrhythmia in patients with paroxysmal AF who had not received prior rhythm control therapy. Serious adverse events were rare.
Safety and efficacy of pulse-induced contour cardiac output monitoring in elderly patients with coronary artery disease and severe heart failure at coronary care units
Authors: Li-ping Qi , Hong-wei Liu , Chang-ming Hong , Yong-yi Bai , Ang Li
Published: October 2022

Background

The optimal treatment for elderly patients with severe heart failure depends on the accurate assessment of their hemodynamic status. Due to its less invasive nature, the safety and efficacy of invasive pulse-induced contour cardiac output (PiCCO)-based hemodynamic monitoring remains uncertain.

Methods

This was a prospective observational study. Between January 2016 and July 2020, 190 elderly patients with severe heart failure were consecutively enrolled. The PiCCO group (89 patients) and non-invasive hemodynamic monitoring group (101 patients) were observed. Hospital stays results were evaluated.

Results

No significant difference in clinical data (P > 0.05) or the incidence of 1-month mortality (16.0 vs. 35.0%, P = 0.141) were observed between groups. The coronary care unit (CCU) stay was shorter in the PiCCO group than in the non-invasive group (40.0 vs. 43.0%, P = 0.049). Indicators such as low Extravascular Lung Water Index (EVLWI), high Body Mass Index (BMI), low Pulmonary Artery Pressure (PAP), and high Left Ventricular Ejection Time (LVET), were associated with favorable clinical results.

Conclusion

Early invasive PiCCO monitoring is safe in critically ill elderly patients with severe heart failure. The hospital stay was reduced using PiCCO monitoring. These encouraging PiCCO results favor its use in elderly patients with severe heart failure at CCUs.
Ethnicity affects the risk factors of acute myocardial infarction and should be considered in educational programs
Authors: Alharbe Umar Abdolah , Alatawi Hanad Hassan , Amirthalingam Palanisamy , Daghriri Sultan Mohammed , Alhwiti Alanoud Abduallah , Alenazi Tahani Saud , Al Ahmare Abdulelah Turki S. , Zaitone Sawsan A. , Aljabri Ahmed , Hamdan Ahmed Mohsen
Published: October 2022

Acute Myocardial infarction is a non-communicable disease representing the leading cause of death in Saudi Arabia. Studying the ethnicity in its risk factors has been poorly investigated.

Objectives

To compare risk factors among Saudi nationals and expatriates.

Methods

A retrospective cohort study for patients admitted to the Cardiac Care Unit of one of the largest tertiary care hospitals in Tabuk diagnosed with acute myocardial infarction from September 2018 to August 2019. Risk factors were compared among groups on the basis of their ethnicity.

Results

In total 18,746 patients were included. Gender and age were the predominant risk factors; Male (p < 0.05) and age >50 years (p < 0.05). There were significant differences between Saudis and expatriates in all measurable parameters indicating that a genetic factor contributes to the risk factors, which was proved by the significant differences between the Middle East North Africa and South Asia subgroups. Interestingly, the mean values of laboratory results were higher than Saudi populations.

Conclusions

The disparity in lipid profile among the studied groups addresses the patient ethnicity should be considered during education programs for the risk factors of cardiovascular disease.
Establishment and validation of a clinical model for predicting diabetic ketosis in patients with type 2 diabetes mellitus
Authors: Qi Mengmeng , Shao Xianfeng , Li Ding , Zhou Yue , Yang Lili , Chi Jingwei , Che Kui , Wang Yangang , Xiao Min , Zhao Yanyun , Kong Zili , Lv Wenshan
Published: October 2022

Background

Diabetic ketosis (DK) is one of the leading causes of hospitalization among patients with diabetes. Failure to recognize DK symptoms may lead to complications, such as diabetic ketoacidosis, severe neurological morbidity, and death.

Purpose

This study aimed to develop and validate a model to predict DK in patients with type 2 diabetes mellitus (T2DM) based on both clinical and biochemical characteristics.

Methods

A cross-sectional study was conducted by evaluating the records of 3,126 patients with T2DM, with or without DK, at The Affiliated Hospital of Qingdao University from January 2015 to May 2022. The patients were divided randomly into the model development (70%) or validation (30%) cohorts. A risk prediction model was constructed using a stepwise logistic regression analysis to assess the risk of DK in the model development cohort. This model was then validated using a second cohort of patients.

Results

The stepwise logistic regression analysis showed that the independent risk factors for DK in patients with T2DM were the 2-h postprandial C-peptide (2hCP) level, age, free fatty acids (FFA), and HbA1c. Based on these factors, we constructed a risk prediction model. The final risk prediction model was L= (0.472a - 0.202b - 0.078c + 0.005d – 4.299), where a = HbA1c level, b = 2hCP, c = age, and d = FFA. The area under the curve (AUC) was 0.917 (95% confidence interval [CI], 0.899–0.934; p<0.001). The discriminatory ability of the model was equivalent in the validation cohort (AUC, 0.922; 95% CI, 0.898–0.946; p<0.001).

Conclusion

This study identified independent risk factors for DK in patients with T2DM and constructed a prediction model based on these factors. The present findings provide an easy-to-use, easily interpretable, and accessible clinical tool for predicting DK in patients with T2DM.
The optimal diagnostic criteria of endogenous hyperinsulinemic hypoglycemia based on a large cohort of Chinese patients
Authors: Yu Jie , Liu Yiwen , Lyu Lu , Zhao Yuan , Qi Mengya , Ping Fan , Xu Lingling , Li Wei , Xu Qiang , Zhang Huabing , Wu Wenming , Li Yuxiu
Published: October 2022

Purpose

An end-of-fast insulin level ≥ 3 µIU/ml, C-peptide level ≥ 0.6 ng/ml, and proinsulin level ≥ 5 pmol/l with end-of-fast glucose level ≤ 3.0 mmol/l have been established as the criteria for endogenous hyperinsulinemic hypoglycemia. However, all these criteria have been proposed based on patients in Western populations. This study aimed to determine the optimal criteria using a large series of Chinese patients.

Methods

This retrospective study comprised 144 patients with surgically proven insulinoma and 40 controls who underwent a 72-h fasting test at the Peking Union Medical College Hospital(PUMCH) from 2000 to 2020. Receiver operating characteristic curves were used for analysis.

Results

In this series of patients, the optimal diagnostic criteria for endogenous hyperinsulinemic hypoglycemia were insulin  ≥ 5.5 μIU/ml, C-peptide ≥ 0.7 ng/ml, and proinsulin ≥ 12 pmol/l with end-of-fast glucose ≤ 2.8 mmol/l; the sensitivity and specificity were 99% and 100% for insulin, 100% and 100% for C-peptide, and 93% and 100% for proinsulin, respectively. The diagnostic efficacy of the criteria based on Western populations was then tested. The sensitivity and specificity of end-of-fast insulin ≥ 3 μIU/ml, C-peptide ≥ 0.6 ng/ml, and proinsulin ≥ 5 pmol/l with end-of-fast glucose ≤ 3.0 mmol/l were 100% and 83%, 100% and 80%, and 97% and 78%, respectively.

Conclusions

New and optimized diagnostic criteria for endogenous hyperinsulinemic hypoglycemia in Chinese populations have been proposed, and these criteria yield satisfactory accuracy.
RPC-based frequency control strategy of LCC-HVDC sending end power system with renewable energy
Authors: Wei Peng , Chai Bin , Shi Lei , Shi Qiaoming , Liu Ruopeng , Wang Yongping , Liu Kai
Published: October 2022

Long-distance transmission of renewable energy via DC is currently a more economical transmission scheme. As the proportion of renewable energy at the generation end continues to rise, the inertia and damping level of the system is reduced, causing serious frequency-related issues. This paper first analyzes the working principle and control method of the LCC-HVDC system, summarizes the frequency control methods of the sending end power grid and their existing problems, and proposes a frequency control scheme for the LCC-HVDC sending end system based on the concept of rapid power compensation (RPC). Finally, the LCC-HVDC system model integrated with the large-capacity wind farm and thermal power plant is built in MATLAB/Simulink. Under conditions of load power fluctuation and sudden wind speed change, the proposed strategy fully utilizes the spare capacity of the system, effectively improves the frequency indexes of the system, and improves the frequency characteristics of the renewable energy sending end grid.
Genetic admixture history and forensic characteristics of Tibeto-Burman-speaking Qiang people explored via the newly developed Y-STR panel and genome-wide SNP data
Authors: He Guanglin , Adnan Atif , Al-Qahtani Wedad Saeed , Safhi Fatmah Ahmed , Yeh Hui-Yuan , Hadi Sibte , Wang Chuan-Chao , Wang Mengge , Liu Chao , Yao Jun
Published: October 2022

Fine-scale patterns of population genetic structure and diversity of ethnolinguistically diverse populations are important for biogeographical ancestry inference, kinship testing, and development and validation of new kits focused on forensic personal identification. Analyses focused on forensic markers and genome-wide single nucleotide polymorphism (SNP) data can provide new insights into the origin, admixture processes, and forensic characteristics of targeted populations. Qiang people had a large sample size among Tibeto-Burmanspeaking populations, which widely resided in the middle latitude of the Tibetan Plateau. However, their genetic structure and forensic features have remained uncharacterized because of the paucity of comprehensive genetic analyses. Here, we first developed and validated the forensic performance of the AGCU-Y30 Y-short tandem repeats (STR) panel, which contains slowly and moderately mutating Y-STRs, and then we conducted comprehensive population genetic analyses based on Y-STRs and genome-wide SNPs to explore the admixture history of Qiang people and their neighbors. The validated results of this panel showed that the new Y-STR kit was sensitive and robust enough for forensic applications. Haplotype diversity (HD) ranging from 0.9932 to 0.9996 and allelic frequencies ranging from 0.001946 to 0.8326 in 514 Qiang people demonstrated that all included markers were highly polymorphic in Tibeto-Burman people. Population genetic analyses based on Y-STRs [RST, FST, multidimensional scaling (MDS) analysis, neighboring-joining (NJ) tree, principal component analysis (PCA), and median-joining network (MJN)] revealed that the Qiang people harbored a paternally close relationship with lowland Tibetan-Yi corridor populations. Furthermore, we conducted a comprehensive population admixture analysis among modern and ancient Eurasian populations based on genome-wide shared SNPs. We found that the Qiang people were a genetically admixed population and showed closest relationship with Tibetan and Neolithic Yellow River farmers. Admixture modeling showed that Qiang people shared the primary ancestry related to Tibetan, supporting the hypothesis of common origin between Tibetan and Qiang people from North China.
Predicting protective gene biomarker of acute coronary syndrome by the circRNA-associated competitive endogenous RNA regulatory network
Authors: Zhang Hengliang , Merkus Daphne , Zhang Pei , Zhang Huifeng , Wang Yanyu , Du Laijing , Kottu Lakshme
Published: October 2022

Background: The mortality and disability rates of acute coronary syndrome (ACS) are quite high. Circular RNA (circRNA) is a competitive endogenous RNA (ceRNA) that plays an important role in the pathophysiology of ACS. Our goal is to screen circRNA-associated ceRNA networks for biomarker genes that are conducive to the diagnosis or exclusion of ACS, and better understand the pathology of the disease through the analysis of immune cells.

Materials and methods: RNA expression profiles for circRNAs (GSE197137), miRNAs (GSE31568), and mRNAs (GSE95368) were obtained from the GEO database, and differentially expressed RNAs (DEcircRNAs, DEmiRNAs, and DEmRNAs) were identified. The circRNA-miRNA and miRNA-mRNA regulatory links were retrieved from the CircInteractome database and TargetScan databases, respectively. As a final step, a regulatory network has been designed for ceRNA. On the basis of the ceRNA network, hub mRNAs were verified by quantitative RT-PCR. Hub genes were validated using a third independent mRNA database GSE60993, and ROC curves were used to evaluate their diagnostic values. The correlation between hub genes and immune cells associated with ACS was then analyzed using single sample gene set enrichment analysis (ssGSEA).

Results: A total of 17 DEcircRNAs, 229 DEmiRNAs, and 27 DEmRNAs were found, as well as 52 circRNA-miRNA pairings and 10 miRNA-mRNA pairings predicted. The ceRNA regulatory network (circRNA-miRNA-mRNA) was constructed, which included 2 circRNA (hsa_circ_0082319 and hsa_circ_0005654), 4 miRNA (hsa-miR-583, hsa-miR-661, hsa-miR-671-5p, hsa-miR-578), and 5 mRNA (XPNPEP1, UCHL1, DBNL, GPC6, and RAD51). The qRT-PCR analysis result showed that the XPNPEP1, UCHL1, GPC6 and RAD51 genes had a significantly decreased expression in ACS patients. Based on ROC curve analysis, we found that XPNPEP1 has important significance in preventing ACS occurrence and excluding ACS diagnosis. ACS immune infiltration analysis revealed significant correlations between the other 3 hub genes (UCHL1, GPC6, RAD51) and the immune cells (Eosinophils, T folliculars, Type 2 T helper cells, and Imumature dendritic cells).

Conclusion: Our study constructed a circRNA-related ceRNA network in ACS. The XPNPEP1 gene could be a protective gene biomarker for ACS. The UCHL1, GPC6 and RAD51 genes were significantly correlated with immune cells in ACS.
Characterization of the SARS-CoV-2 co-receptor NRP1 expression profiles in healthy people and cancer patients: Implication for susceptibility to COVID-19 disease and potential therapeutic strategy
Authors: Huang Yongbiao , Wang Yuan , Xu Duo , Xiao Lingyan , Qin Wan , Liu Bo , Yuan Xianglin
Published: October 2022

Neuropilin-1 (NRP1) is a transmembrane protein involved in many physiological and pathological processes, and it functions as a co-receptor to facilitate the entry of SARS-CoV-2 into host cells. Therefore, it is critical to predict the susceptibility to SARS-CoV-2 and prognosis after infection among healthy people and cancer patients based on expression of NRP1. In the current study, we analyzed the conservation and isoform of NRP1 using public databases. NRP1 expression landscape in healthy people, COVID-19 patients, and cancer patients at both bulk and single-cell RNA-seq level was also depicted. We also analyzed the relationship between tissue-specific NRP1 expression and overall survival (OS), as well as tumor immune environment at a pan-cancer level, providing a comprehensive insight into the relationship between the vulnerability to SARS-CoV-2 infection and tumorigenesis. In conclusion, we identified NRP1 as a potential biomarker in predicting susceptibility to SARS-CoV-2 infection among healthy people and cancer patients.
Mettl14-mediated m6A modification enhances the function of Foxp3+ regulatory T cells and promotes allograft acceptance
Authors: Liu Yanzhuo , Yuan Yinglin , Zhou Zili , Cui Yuanyuan , Teng Yan , Huang Hao , Yuan Hao , Zhang Yanling , Yang Lu , Zhao Gaoping
Published: October 2022

N6-methyladenosine (m6A), the most prevalent form of internal mRNA modification, is extensively involved in Treg cells differentiation and function. However, the involvement of m6A in functional Treg cells for transplantation tolerance remains to be elucidated. By using an experimental transplantation mouse model, we found that m6A levels in Treg cells were altered during the induction of transplant tolerance by performing a dot blotting assay. Subsequently, we used the heterogenic Treg-specific Mettl14 knockout mice (Foxp3-Mettl14f/+ cKO) to reduce METTL14 expression and performed islets allograft transplantation. Our result revealed that reduced expression of METTL14 prevented Treg cells expansion and promoted the infiltration of CD4+ and CD8+ T cells around the allograft, which led to rapid allograft rejection in Foxp3-Mettl14f/+ cKO mice. The expression of regulatory cytokines including IL-10 and TGF-β was significantly decreased in Foxp3-Mettl14f/+ cKO mice, and the suppressive function of Treg cells was also abrogated. In addition, an analysis of RNA-seq data revealed that the SOCS family (SOCS1, SOCS2 and SOCS3) is the subsequent signaling pathway affected by the METTL14 mediated m6A modification in Treg cells to modulate the suppressive function after transplantation. Taken together, our study showed for the first time that the METTL14-mediated m6A modification is essential for the suppressive function of Treg cells in transplantation and may serve as a regulatory element of Treg cell-based therapy in transplant medicine.
Case report: Severe combined immunodeficiency with ligase 1 deficiency and Omenn-like manifestation
Authors: Dabrowska-Leonik Nel , Pastorczak Agata Karolina , Bąbol-Pokora Katarzyna , Bernat-Sitarz Katarzyna , Piątosa Barbara , Heropolitańska-Pliszka Edyta , Kacprzak Magdalena M. , Kalwak Krzysztof , Gul Katarzyna , Burg Mirjam van der , Ussowicz Marek , Pac Malgorzata
Published: October 2022

DNA ligase I deficiency is an extremely rare primary immunodeficiency with only 6 patients reported in the literature. Most common manifestations include radiosensitivity, macrocytic anemia, lymphopenia with an increased percentage of gamma-delta T cells, and hypogammaglobulinemia requiring replacement therapy. Two-month-old girl with delayed development, T-B-NK+ SCID, and macrocytic anemia presented features of Omenn syndrome. Whole exome sequencing revealed two novel, heterozygous variants (c.2312 G>A, p.Arg771Gly and c.776+5G>T, p.Pro260*) in the LIG1 gene (NM_000234.1). Hematopoietic stem cell transplantation from a fully matched unrelated donor was performed at the age of 4 months using GEFA03 protocol. Mixed donor-recipient chimerism was observed, with 60-70% chimerism in the mononucleated cell compartment and over 90% in T-lymphocyte compartment, but autologous myeloid recovery. Stable CD4+ and CD8+ T-cell counts above 200/µL were achieved after 2 months, but the patient remained transfusion-dependent. Despite satisfactory immunological reconstitution, the second transplantation due to constitutional hemolytic defect has been considered. In light of possible re-transplantation, an issue of optimal conditioning protocol with sufficient myeloid engraftment is important. For the first time Omenn syndrome is described in a compound heterozygote carrying two the novel variants p.Arg771Gly and p.Pro260* in the LIG1 gene. Patients diagnosed with SCID and Omenn syndrome showing macrocytic anemia, should be screened for DNA ligase I deficiency.
MiR-93-5p promotes granulosa cell apoptosis and ferroptosis by the NF-kB signaling pathway in polycystic ovary syndrome
Authors: Tan Wei , Dai Fangfang , Yang Dongyong , Deng Zhimin , Gu Ran , Zhao Xiaomiao , Cheng Yanxiang
Published: October 2022

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women of reproductive age. miR-93-5p has been reported to be elevated in granulosa cells of PCOS patients. However, the mechanism by which miR-93-5p drives granulosa cell (GC) progression remains unclear. Thus, this study focuses on the roles and mechanisms of miR-93-5p in the GCs of PCOS.

Methods

KGN cells have similar ovarian physiological characteristics and are used to study the function and regulatory mechanism of GCs. In this study, KGN cells were transfected with si-NC, si-miR93-5p, oe-NC and oe-miR93-5p. A cell counting kit-8 assay, flow cytometry and western blotting were performed to observe the proliferation and apoptosis of KGN in different groups. Subsequently, the levels of reactive oxygen species, malondialdehyde, GPX4, SLC7A11 and Nrf2, which are indicators of ferroptosis, were measured by a dihydroethidium fluorescent dye probe, biochemical kit, western blotting and reverse transcription quantitative polymerase chain reaction. Ultimately, bioinformatic analysis and experimental methods were used to examine the interaction between miR-93-5p and the NF-κB signaling pathway.

Results

miR-93-5p was upregulated in the GCs of PCOS patients. Overexpression of miR-93-5p promoted apoptosis and ferroptosis in KGN cells, while knockdown of miR-93-5p showed the reverse effect. Biological analysis and subsequent experiments demonstrated that miR-93-5p negatively regulates the NF- κB signaling pathway.

Conclusion

miR-93-5p promotes the apoptosis and ferroptosis in GC by regulating the NF-κB signaling pathway. Silencing of miR-93-5p protects against GC dysfunction. Our study identified miR-93-5p as a new molecular target for improving the function of GCs in PCOS patients.
GJB3 promotes pancreatic cancer liver metastasis by enhancing the polarization and survival of neutrophil
Authors: Huo Yanmiao , Zhou Yaoqi , Zheng Jiahao , Jin Guangxin , Tao Lingye , Yao Hongfei , Zhang Junfeng , Sun Yongwei , Liu Yingbin , Hu Li-Peng
Published: October 2022

Connexins are membrane expressed proteins, which could assemble into hexamers to transfer metabolites and secondary messengers. However, its roles in pancreatic cancer metastasis remains unknown. In this study, by comparing the gene expression patterns in primary pancreatic cancer patients primary and liver metastasis specimens, we found that Gap Junction Protein Beta 3 (GJB3) significantly increased in Pancreatic ductal adenocarcinoma (PDAC) liver metastasis. Animal experiments verified that GJB3 depletion suppressed the hepatic metastasis of PDAC cancer cells. Further, GJB3 over expression increased the neutrophil infiltration. Mechanistic study revealed that GJB3 form channels between PDAC tumor cells and accumulated neutrophil, which transfer cyclic adenosine monophosphate (cAMP) from cancer to neutrophil cells, which supports the survival and polarization. Taken together, our data suggesting that GJB3 could act as a potential therapeutic target of PDAC liver metastasis.
Distribution, spectral characteristics, and seasonal variation of dissolved organic matter in the northern Beibu Gulf, South China Sea
Authors: Zhu Zuhao , Wei Huihua , Guan Yao , Zhang Li , Jia Renming , Sun Pengfei , Yang Yang , Zhang Zhen , Zhang Qiufeng
Published: October 2022

Dissolved organic matter (DOM) in the land–ocean interface plays a critical role in the global carbon cycle, yet its dynamic is not well understood. Dissolved organic carbon (DOC) in the northern Beibu Gulf was measured seasonally from April 2020 to January 2021. Chromophoric and fluorescent DOM (CDOM and FDOM) were synchronously characterized by absorption and fluorescence spectroscopy. Three fluorescent components were identified from 597 samples using parallel factor analysis, including two humic-like and one protein-like component. DOC displays a significant seasonality with the average level being highest in summer (177 μmol/L) and lowest in winter (107 μmol/L). CDOM and FDOM levels in summer are also higher than those in winter. Although the variation ranges of DOC, CDOM, and FDOM in surface water are generally greater than in bottom water, the difference between the two layers is statistically insignificant. River discharge and anthropogenic input are important external sources of DOM in the low-salinity nearshore waters (i.e., estuaries and coast), whereas DOM in offshore waters is mainly produced by in situ biological activity. The mixing behavior of DOM in the northern Beibu Gulf varies spatially but minimally on a seasonal scale. Two distinct conservative mixing behaviors of DOC, CDOM, and humic-like FDOM occur in the nearshore waters from Tieshangang Bay and excluding Tieshangang Bay, respectively. The removal of protein-like FDOM along the salinity gradient and the negative correlation between protein-like FDOM intensity and apparent oxygen utilization are pronounced in the nearshore waters excluding Tieshangang Bay, jointly indicating that oxygen is consumed by microbial communities. In contrast, a net addition of DOC occurs in the high-salinity offshore waters, whereas the CDOM and humic-like FDOM undergoes quasi-conservative mixing. Overall, this study reveals notable spatial and seasonal variations in the concentration, source, and mixing of DOM at the land–ocean interface and highlights the importance of sources and processes in shaping the amount and composition of DOM exported to the ocean margin.