BACKGROUND Leiomyomas(LMs)are mesenchymal tumors that arise from smooth muscle cells.LMs most commonly arise in organs with an abundance of smooth muscle such as the uterus and gastrointestinal tract.Conversely,LMs ar...BACKGROUND Leiomyomas(LMs)are mesenchymal tumors that arise from smooth muscle cells.LMs most commonly arise in organs with an abundance of smooth muscle such as the uterus and gastrointestinal tract.Conversely,LMs are rarely detected in the head and neck region.In this study,we report a rare case of laryngeal LM(LLM)and summarized the clinical characteristics of reported LLMs to help clinicians better understand this rare disease and improve its diagnosis,treatment,and postoperative course.CASE SUMMARY A 49-year-old man was admitted to our ENT outpatient clinic with a chief complaint of pharynx discomfort for 2 months.Laryngoscopy performed under topical anesthesia revealed a solitary,pink mass at the tubercle of epiglottis.Surgery via laryngeal endoscopy was performed under general anesthesia,and the lesion was excised easily.Positive immunohistochemical staining for desmin and smooth-muscle actin indicated a smooth muscle origin and the diagnosis was laryngeal leiomyoma.After surgery,the patient’s condition was stable,and he was discharged 2 d after surgery.During the 1-year postoperative period,the patient’s condition remained stable without evidence of recurrence.CONCLUSION Surgical resection is the preferred treatment for LLMs,its early diagnosis and differential diagnosis have important clinical significance.展开更多
In view of engineering application, it is practicable to decompose the aerodynamics into three components: the static aerodynamics, the aerodynamic increment due to steady rotations, and the aerodynamic increment due...In view of engineering application, it is practicable to decompose the aerodynamics into three components: the static aerodynamics, the aerodynamic increment due to steady rotations, and the aerodynamic increment due to unsteady separated and vortical flow. The first and the second components can be presented in conventional forms, while the third is described using a one-order differential equation and a radial-basis-function (RBF) network. For an aircraft configuration, the mathematical models of 6- component aerodynamic coefficients are set up from the wind tunnel test data of pitch, yaw, roll, and coupled yawroll large-amplitude oscillations. The flight dynamics of an aircraft is studied by the bifurcation analysis technique in the case of quasi-steady aerodynamics and unsteady aerodynam- ics, respectively. The results show that: (1) unsteady aerodynamics has no effect upon the existence of trim points, but affects their stability; (2) unsteady aerodynamics has great effects upon the existence, stability, and amplitudes of periodic solutions; and (3) unsteady aerodynamics changes the stable regions of trim points obviously. Furthermore, the dynamic responses of the aircraft to elevator deflections are inspected. It is shown that the unsteady aerodynamics is beneficial to dynamic stability for the present aircraft. Finally, the effects of unsteady aerodynamics on the post-stall maneuverability展开更多
Measuring the dust explosion characteristics of aluminum-based activated fuels was a prerequisite for developing effective prevention and control measures.In this paper,ignition sensitivity,flame propagation behaviors...Measuring the dust explosion characteristics of aluminum-based activated fuels was a prerequisite for developing effective prevention and control measures.In this paper,ignition sensitivity,flame propagation behaviors and explosion severity of aluminum/polytetrafluoroethylene(Al/PTFE)compositions including 2 PT(2.80 wt.%F),4 PT(7.18 wt.%F)and 8 PT(11.90 wt.%F)were studied.When the content of F increased from 2.80 wt.%to 11.90 wt.%,the minimum explosive concentration MEC decreased from380 g/m^(3)to 140 g/m^(3),due to the dual effects of increased internal active aluminum and enhanced reactivity.The average flame propagation velocities increased as the percentage of F increased.The maximum explosion pressure Pmof 500 g/m3aluminum-based activated fuels increased from 247 k Pa to299 kPa.Scanning electron microscopy demonstrated that with the increase of PTFE content,the reaction was more complete.On this basis,the explosion mechanism of aluminum-based activated fuels was revealed.展开更多
Background: Measuring total serum calcium is important for the diagnosis of diseases. Currently, results from commercial kits for calcium measurement are variable. Generally, the performance of serum calcium measurem...Background: Measuring total serum calcium is important for the diagnosis of diseases. Currently, results from commercial kits for calcium measurement are variable. Generally, the performance of serum calcium measurements is monitored by external quality assessment (EQA) or proficiency testing schemes. However, the commutability of the EQA samples and calibrators is often unknown, which limits the effectiveness of EQA schemes. The aim of this study was to evaluate the bias of serum calcium measurements and the commutability of processed materials. Methods: Inductively coupled plasma mass spectrometry was applied as a comparative method, and 14 routine methods were chosen as test methods. Forty-eight serum samples from individual patients and 25 processed materials were quantified. A scatter plot was generated from patient samples, and 95% prediction intervals were calculated to evaluate the commutability of the processed materials and measurement bias at three concentration levels was used to determine the accuracy of routine assays. Results: All assays showed high precision (total coefficient of variation [CV] 〈2.26%) and correlation coefficients (r 〉 0.99). For all assays, the mean bias for the 48 patient samples ranged from 0.13 mmol/L to 0.00 mmol/L (-5.61 0.01%), and the ranges for the three concentrations were 0.10-0.04 mmoUL (-5.71-2.35%), -0.14-0.01 mmol/L (-5.80-0.30%), and -0.19-0.04 mmol/L (-6.24-1.22%). The EQA samples, calibrators, and animal sera exhibited matrix effects in some assays; human serum pools were commutable in all assays; certificate reference materials were commutable in most assays, and only GBW09152 exhibited a matrix effect in one assay: and aqueous reference materials exhibited matrix effects in most assays. Conclusions: Biases for most assays were within the acceptable range, although the accuracy of some assays needs improvement. Human serum pools prepared from patient samples were commutable, and the other tested materials exhibited a matrix effect.展开更多
Background: Hemoglobin A 1 c (HbA1 c) measurement is of great value for the diagnosis and monitoring of diabetes. Many manufacturers have developed various experiments to determine the HbAlc concentration. However,...Background: Hemoglobin A 1 c (HbA1 c) measurement is of great value for the diagnosis and monitoring of diabetes. Many manufacturers have developed various experiments to determine the HbAlc concentration. However, the longitudinal use of these tests requires strict quality management. This study aimed to analyze the quality of HbAlc measurement systems in China using six sigma techniques to help improve their performances. Methods: A total of 135 laboratories were involved in this investigation in 2015. Bias values and coefficients of variation were collected from an HbA 1 c trueness verification external quality assessment program and an internal quality control program organized by the National Center of Clinical Laboratories in China. The sigma (σ) values and the quality goal index (QGI) were used to evaluate the performances of different groups, which were divided according to principles and instruments. Results: The majority of participants (88, 65.2%) were scored as "improvement needed (σ 〈 3)", suggesting that the laboratories needed to improve their measurement performance. Only 8.2% (11/135) of the laboratories were scored as "world class (σ≥ 6)". Among all the 88 laboratories whose σ values were below 3, 52 (59.1%) and 23 (26.1%) laboratories needed to improve measurement precision (QGI 〈8.0) and trueness (QGI 〉 1.2), respectively; the remaining laboratories (13, 14.8%) needed to improve both measurement precision and trueness. In addition, 16.1% (5/31) and 15.0% (3/20) of the laboratories in "TO SOH" and "ARKRAY" groups, respectively, were scored as "world class", whereas none of the laboratories in "BIO-RAD" group were scored as "world class". Conclusions: This study indicated that, although participating laboratories were laboratories with better performance in China, the performances were still unsatisfactory. Actions should be taken to improve HbAlc measurement performance before we can include HbAlc assays in diabetes diagnosis in China.展开更多
The 10th edition of the Global Trajectory Optimization Competition considered the problem of the galaxy settlement wherein competitors from all over the world were expected to design the trajectories of different sett...The 10th edition of the Global Trajectory Optimization Competition considered the problem of the galaxy settlement wherein competitors from all over the world were expected to design the trajectories of different settler vessels to maximize the given multi-faceted merit function.The synthesis methods used by the winning team,led jointly by the National University of Defense Technology(NUDT)and Xi’an Satellite Control Center(XSCC),are described along with a greedy search method and the improved solution obtained by University of Jena.Specifically,we presented a layout-first topology-second approach that allows an efficient settlement tree search guided by the pre-specified ideal spatial distribution.We also explained how the problem of constructing settlement trees can be modeled as the widely studied minimum spanning tree problem.Furthermore,University of Jena explored the possibility that a greedy search can generate even better settlement trees,based on the same initial conditions,when compared to that of the winning solution.展开更多
基金Supported by National Natural Science Foundation of China,No.82071031。
文摘BACKGROUND Leiomyomas(LMs)are mesenchymal tumors that arise from smooth muscle cells.LMs most commonly arise in organs with an abundance of smooth muscle such as the uterus and gastrointestinal tract.Conversely,LMs are rarely detected in the head and neck region.In this study,we report a rare case of laryngeal LM(LLM)and summarized the clinical characteristics of reported LLMs to help clinicians better understand this rare disease and improve its diagnosis,treatment,and postoperative course.CASE SUMMARY A 49-year-old man was admitted to our ENT outpatient clinic with a chief complaint of pharynx discomfort for 2 months.Laryngoscopy performed under topical anesthesia revealed a solitary,pink mass at the tubercle of epiglottis.Surgery via laryngeal endoscopy was performed under general anesthesia,and the lesion was excised easily.Positive immunohistochemical staining for desmin and smooth-muscle actin indicated a smooth muscle origin and the diagnosis was laryngeal leiomyoma.After surgery,the patient’s condition was stable,and he was discharged 2 d after surgery.During the 1-year postoperative period,the patient’s condition remained stable without evidence of recurrence.CONCLUSION Surgical resection is the preferred treatment for LLMs,its early diagnosis and differential diagnosis have important clinical significance.
文摘In view of engineering application, it is practicable to decompose the aerodynamics into three components: the static aerodynamics, the aerodynamic increment due to steady rotations, and the aerodynamic increment due to unsteady separated and vortical flow. The first and the second components can be presented in conventional forms, while the third is described using a one-order differential equation and a radial-basis-function (RBF) network. For an aircraft configuration, the mathematical models of 6- component aerodynamic coefficients are set up from the wind tunnel test data of pitch, yaw, roll, and coupled yawroll large-amplitude oscillations. The flight dynamics of an aircraft is studied by the bifurcation analysis technique in the case of quasi-steady aerodynamics and unsteady aerodynam- ics, respectively. The results show that: (1) unsteady aerodynamics has no effect upon the existence of trim points, but affects their stability; (2) unsteady aerodynamics has great effects upon the existence, stability, and amplitudes of periodic solutions; and (3) unsteady aerodynamics changes the stable regions of trim points obviously. Furthermore, the dynamic responses of the aircraft to elevator deflections are inspected. It is shown that the unsteady aerodynamics is beneficial to dynamic stability for the present aircraft. Finally, the effects of unsteady aerodynamics on the post-stall maneuverability
基金financially supported by National Natural Science Foundation of China(No.51922025 and No.51874066)China Postdoctoral Science Foundation(No.2020M670759)the Fundamental Research Funds for the Central Universities(No.DUT20GJ201)。
文摘Measuring the dust explosion characteristics of aluminum-based activated fuels was a prerequisite for developing effective prevention and control measures.In this paper,ignition sensitivity,flame propagation behaviors and explosion severity of aluminum/polytetrafluoroethylene(Al/PTFE)compositions including 2 PT(2.80 wt.%F),4 PT(7.18 wt.%F)and 8 PT(11.90 wt.%F)were studied.When the content of F increased from 2.80 wt.%to 11.90 wt.%,the minimum explosive concentration MEC decreased from380 g/m^(3)to 140 g/m^(3),due to the dual effects of increased internal active aluminum and enhanced reactivity.The average flame propagation velocities increased as the percentage of F increased.The maximum explosion pressure Pmof 500 g/m3aluminum-based activated fuels increased from 247 k Pa to299 kPa.Scanning electron microscopy demonstrated that with the increase of PTFE content,the reaction was more complete.On this basis,the explosion mechanism of aluminum-based activated fuels was revealed.
文摘Background: Measuring total serum calcium is important for the diagnosis of diseases. Currently, results from commercial kits for calcium measurement are variable. Generally, the performance of serum calcium measurements is monitored by external quality assessment (EQA) or proficiency testing schemes. However, the commutability of the EQA samples and calibrators is often unknown, which limits the effectiveness of EQA schemes. The aim of this study was to evaluate the bias of serum calcium measurements and the commutability of processed materials. Methods: Inductively coupled plasma mass spectrometry was applied as a comparative method, and 14 routine methods were chosen as test methods. Forty-eight serum samples from individual patients and 25 processed materials were quantified. A scatter plot was generated from patient samples, and 95% prediction intervals were calculated to evaluate the commutability of the processed materials and measurement bias at three concentration levels was used to determine the accuracy of routine assays. Results: All assays showed high precision (total coefficient of variation [CV] 〈2.26%) and correlation coefficients (r 〉 0.99). For all assays, the mean bias for the 48 patient samples ranged from 0.13 mmol/L to 0.00 mmol/L (-5.61 0.01%), and the ranges for the three concentrations were 0.10-0.04 mmoUL (-5.71-2.35%), -0.14-0.01 mmol/L (-5.80-0.30%), and -0.19-0.04 mmol/L (-6.24-1.22%). The EQA samples, calibrators, and animal sera exhibited matrix effects in some assays; human serum pools were commutable in all assays; certificate reference materials were commutable in most assays, and only GBW09152 exhibited a matrix effect in one assay: and aqueous reference materials exhibited matrix effects in most assays. Conclusions: Biases for most assays were within the acceptable range, although the accuracy of some assays needs improvement. Human serum pools prepared from patient samples were commutable, and the other tested materials exhibited a matrix effect.
文摘Background: Hemoglobin A 1 c (HbA1 c) measurement is of great value for the diagnosis and monitoring of diabetes. Many manufacturers have developed various experiments to determine the HbAlc concentration. However, the longitudinal use of these tests requires strict quality management. This study aimed to analyze the quality of HbAlc measurement systems in China using six sigma techniques to help improve their performances. Methods: A total of 135 laboratories were involved in this investigation in 2015. Bias values and coefficients of variation were collected from an HbA 1 c trueness verification external quality assessment program and an internal quality control program organized by the National Center of Clinical Laboratories in China. The sigma (σ) values and the quality goal index (QGI) were used to evaluate the performances of different groups, which were divided according to principles and instruments. Results: The majority of participants (88, 65.2%) were scored as "improvement needed (σ 〈 3)", suggesting that the laboratories needed to improve their measurement performance. Only 8.2% (11/135) of the laboratories were scored as "world class (σ≥ 6)". Among all the 88 laboratories whose σ values were below 3, 52 (59.1%) and 23 (26.1%) laboratories needed to improve measurement precision (QGI 〈8.0) and trueness (QGI 〉 1.2), respectively; the remaining laboratories (13, 14.8%) needed to improve both measurement precision and trueness. In addition, 16.1% (5/31) and 15.0% (3/20) of the laboratories in "TO SOH" and "ARKRAY" groups, respectively, were scored as "world class", whereas none of the laboratories in "BIO-RAD" group were scored as "world class". Conclusions: This study indicated that, although participating laboratories were laboratories with better performance in China, the performances were still unsatisfactory. Actions should be taken to improve HbAlc measurement performance before we can include HbAlc assays in diabetes diagnosis in China.
基金This study is supported by the National Natural Science Foundation of China(No.11702330)the National Science and Technology Innovation Special Zone Project.
文摘The 10th edition of the Global Trajectory Optimization Competition considered the problem of the galaxy settlement wherein competitors from all over the world were expected to design the trajectories of different settler vessels to maximize the given multi-faceted merit function.The synthesis methods used by the winning team,led jointly by the National University of Defense Technology(NUDT)and Xi’an Satellite Control Center(XSCC),are described along with a greedy search method and the improved solution obtained by University of Jena.Specifically,we presented a layout-first topology-second approach that allows an efficient settlement tree search guided by the pre-specified ideal spatial distribution.We also explained how the problem of constructing settlement trees can be modeled as the widely studied minimum spanning tree problem.Furthermore,University of Jena explored the possibility that a greedy search can generate even better settlement trees,based on the same initial conditions,when compared to that of the winning solution.