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Ma Q, Wang X, Niu S, Zeng H, Ullah S. Analysis on congestion mechanism of CAVs around traffic accident zones. ACCIDENT; ANALYSIS AND PREVENTION 2024; 205:107663. [PMID: 38901162 DOI: 10.1016/j.aap.2024.107663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 05/18/2024] [Accepted: 05/28/2024] [Indexed: 06/22/2024]
Abstract
Unexpected traffic accidents cause traffic congestion and aggravate the unsafe situation on the roadways. Reducing the impact of such congestion by introducing Connected and Autonomous Vehicles (CAVs) into the traditional traffic flow is possible. It requires estimating the incident's duration and analyzing the incident's impact area to determine the appropriate strategy. To guide the driver in making efficient and accurate judgments and avoiding secondary traffic congestion, the Cooperative Adaptive Cruise Control (CACC) model with dynamic safety distance and the Intelligent Driver Model (IDM) based on the safety potential field theory are introduced to build the evolution model of accidental traffic congestion under diversion interference and non-interference. The Huatao Interchange section of the Inner Ring Highway in the Banan District of Chongqing, China, was selected as the test section for simulating mixed traffic flow under different CAVs permeability (Pc). The relationship between the evacuation time, evacuation traffic volume, and the accident impact degree index (including the farthest queue length and accident duration) under the diversion intervention scenario was analyzed, respectively. The results of the study indicate that the higher the penetration of CAVs, the more significant the improvement in traffic flow occupancy, flow, and speed. Diversion interventions reduce congestion, about 50 % of the duration without interventions, when Pc ≤ 80 %. The traffic volume of diversion interference is non-linearly positively correlated with the maximum queue length, and the earlier the interference time, the stronger the positive correlation. The negative correlation between the interference time and queue length is weak at low evacuation traffic volume. With the increase in evacuation traffic volume, the influence of evacuation time on queue length becomes stronger. The maximum queue length value interval under different conditions is [348 m, 3140 m], and the shortest evacuation time is [1649 s, 2834 s]. The traffic flow data obtained from the simulation are imported into the episodic traffic congestion evolution model. The congestion evaluation indexes are calculated under non-interference and interference measures and compared with the simulation results. The maximum relative error is within 5.38 %. The results can be of great significance in relieving congestion caused by traffic accidents and promptly restoring road capacity.
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Wang F, Ma Q, Liu X, Liang C, Yang H, Chen J, Shen Y. Managing ischemic and necrotic incarcerated femoral hernia contents and their risk factors. Hernia 2024; 28:1373-1379. [PMID: 38687408 DOI: 10.1007/s10029-024-03056-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 04/18/2024] [Indexed: 05/02/2024]
Abstract
PURPOSE Incarcerated femoral hernia patients had high risk of hernia contents necrosis. We provide our experience of management ischemia and necrosis of hernia contents in emergency incarcerated femoral hernia patients, and to investigate its risk factors. METHODS This is a case-control study. Eighty-nine incarcerated femoral patients who underwent emergency surgery from January 2015 to December 2021 were included, and divided into normal group (60 cases) and ischemia/necrosis group (29 cases) according to the intraoperative condition of hernia contents. The surgical methods, intraoperative and postoperative conditions were compared between the two groups. Multivariate logistic regression was used to analyze the risk factors of ischemia and necrosis of hernia contents. RESULTS Open preperitoneal tension-free repair was the most commonly used surgical methods (68.5%) for incarcerated femoral patients. The utilization rate of laparoscopic repair in the ischemia/necrosis group was lower than that in the normal group (13.8% vs. 20.0%, P = 0.475). The proportion of mesh placement in the normal group was significantly higher than that in the ischemia/necrosis group (98.3% vs 65.5%, P < 0.001). The hernia contents resection rate (55.2% vs 1.7%), operation time (90 vs 40 min), intraoperative bleeding (5 vs 2 ml), ICU admission rate (31.0% vs 1.7%), and hospital stay (7 vs 4 d) were significantly higher in the ischemia/necrosis group than those in normal group. Results of multivariate logistic regression showed that incarceration time more than 9 h (aOR = 19.3, 95%CI: 1.9-192.9) was an independent risk factor for ischemia and necrosis of hernia contents in emergency incarcerated femoral hernia patients. CONCLUSION Open tension-free repair was the most commonly used surgical methods for emergency incarcerated femoral hernia patients. Ischemia and necrosis of hernia contents will increase bowel resection rate and prolong operation and hospital stay. Long incarceration time is an independent risk factor for ischemia and necrosis of hernia contents.
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Diao H, Lu G, Zhang Y, Wang Z, Liu X, Ma Q, Yu H, Li Y. Risk factors for multidrug-resistant and extensively drug-resistant Acinetobacter baumannii infection of patients admitted in intensive care unit: a systematic review and meta-analysis. J Hosp Infect 2024; 149:77-87. [PMID: 38710306 DOI: 10.1016/j.jhin.2024.04.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 04/17/2024] [Accepted: 04/20/2024] [Indexed: 05/08/2024]
Abstract
BACKGROUND Multidrug-resistant (MDR) and extensively drug-resistant (XDR) Acinetobacter baumannii infections pose challenges for clinical treatment and cause high mortality, particularly in intensive care units (ICUs). AIM To systematically summarize and analyse the risk factors for MDR/XDR A. baumannii-infected patients admitted to ICUs. METHODS PubMed, Embase, Web of Science, and the Cochrane Library were searched for eligible original studies published in English before October 2023. Meta-analysis was conducted where appropriate, with mean differences (MDs) and odds ratios (ORs) calculated for continuous and nominal scaled data. The quality of included studies was assessed using the Newcastle-Ottawa Scale (NOS). FINDINGS Ten studies reporting 1199 ICU patients (604 from general ICUs, 435 from neonatal ICUs, and 160 from paediatric ICUs) from eight countries were included in our analysis. Risk factors associated with MDR A. baumannii infection among patients admitted to general ICUs included high Acute Physiology And Clinical Health II (APACHE Ⅱ) score (mean difference (MD): 7.52; 95% confidence interval (CI): 3.24-11.80; P = 0.0006), invasive procedures (odds ratio (OR): 3.47; 95% CI: 1.70-7.10; P = 0.0006), longer ICU stay (MD: 3.40; 95% CI: 2.94-3.86; P < 0.00001), and use of antibiotics (OR: 2.69; 95% CI: 1.22-5.94; P = 0.01). In the sub-group analysis, longer neonatal ICU stay (MD: 16.88; 95% CI: 9.79-23.97; P < 0.00001) was associated with XDR A. baumannii infection. CONCLUSION Close attention should be paid to patients with longer ICU stays, undergoing invasive procedures, using antibiotics, and with high APACHE Ⅱ scores to reduce the risk of MDR and XDR A. baumannii infections.
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Qiao J, Kang H, Ran Q, Tong H, Ma Q, Wang S, Zhang W, Wu H. Metabolic habitat imaging with hemodynamic heterogeneity predicts individual progression-free survival in high-grade glioma. Clin Radiol 2024; 79:e842-e853. [PMID: 38582632 DOI: 10.1016/j.crad.2024.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 12/07/2023] [Accepted: 02/10/2024] [Indexed: 04/08/2024]
Abstract
AIM We design a feasibility study to obtain a set of metabolic-hemodynamic habitats for tackling tumor spatial metabolic patterns with hemodynamic information. MATERIALS AND METHODS Preoperative data from 69 high-grade gliomas (HGG) patients with subsequent histologic confirmation of HGG were prospectively collected (January 2016 to March 2020) after concurrent chemoradiotherapy (CCRT). Four vascular habitats were automatically segmented by multiparametric magnetic resonance imaging (MRI). The metabolic information, either at enhancing or edema tumor regions, was obtained by two neuroradiologists. The relative habitat volumes were used for weight estimation procedures for computing the coefficients of a linear regression model using weighted least squares (WLS) for metabolite semiquantifications (i.e. the Cho/NAA ratio and the Cho/Cr ratio) at vascular habitats. Multivariate Cox proportional hazard regression analyses are used to obtain the odds ratio (OR) and develop a nomogram using weighted estimators corresponding to each covariate derived from Cox regression coefficients. RESULTS There was a strongly correlation between perfusion indexes and the Cho/Cr ratio (rCBV, r=0.71) or Cho/NAA ratio (rCBV, r=0.66) at high-angiogenic enhancing tumor habitats (HAT) habitat. Compared isocitrate dehydrogenase (IDH) mutation to their wild type, the IDH wild type had significantly decreased Cho/Cr ratio (IDH mutation: Cho/Cr ratio = 2.44 ± 0.33, IDH wildtype: Cho/Cr ratio = 2.66 ± 0.36, p=0.02) and Cho/NAA ratio (IDH mutation: Cho/Cr ratio = 4.59 ± 0.61, IDH wildtype: Cho/Cr ratio = 4.99 ± 0.66, p=0.022) at the HAT. The C-index for the median progression-free survival (PFS) prediction was 0.769 for the Cho/NAA nomogram and 0.747 for the Cho/Cr nomogram through 1000 bootstrapping validation. CONCLUSIONS Our findings suggest that spatial metabolism combined with hemodynamic heterogeneity is associated with individual PFS to HGG patients post-CCRT.
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Liu F, Yan WQ, Ma Q, Liu YB, Yang ZB. [Clinical effect of anterolateral thigh flow-through chimeric perforator free flap transplantation in the treatment of upper limb complex tissue defects with main artery injury]. ZHONGHUA SHAO SHANG YU CHUANG MIAN XIU FU ZA ZHI 2024; 40:172-179. [PMID: 38418179 DOI: 10.3760/cma.j.cn501225-20231103-00176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 03/01/2024]
Abstract
Objective: To investigate the clinical effect of anterolateral thigh flow-through chimeric perforator free flap transplantation in the treatment of upper limb complex tissue defects with main artery injury. Methods: The study was a retrospective observational study. From May 2019 to January 2022, 11 patients with upper limb complex tissue defects combined with main artery injury who met the inclusion criteria were admitted to the Department of Hand, Foot and Ankle Surgery of General Hospital of Ningxia Medical University, including 7 males and 4 females, aged from 18 to 56 years. After debridement, the area of skin and soft tissue defects was from 20 cm×6 cm to 32 cm×10 cm, and the exposed area of dead cavity or deep tissue was from 7 cm×4 cm to 10 cm×7 cm. Three patients had radial artery defects with a length of 4 to 7 cm; two patients had ulnar artery defects with a length of 5 to 8 cm; 4 patients had defects in both ulnar and radial arteries with a length of 3 to 7 cm; and in two patients, the ulnar, radial and brachial arteries were all defective with a length of 4 to 8 cm. The anterolateral thigh flow-through chimeric perforator flap was designed and cut. The skin flap area was from 22 cm×7 cm to 32 cm×11 cm, the chimeric muscle flap area was from 7 cm×4 cm to 10 cm×7 cm, and the length of the flow-through vessel in the "T" shaped vessel pedicle was from 4 to 8 cm. When transplanting the skin flap, the proximal end of the vascular pedicle was anastomosed with the proximal end of the recipient site, and the distal end of the vascular pedicle was anastomosed with the more normal blood vessel at the distal end of the forearm; the invalid cavity was filled with the muscle flap. The donor site wounds of tissue flap were closed directly or treated with skin grafting. After operation, the blood supply and survival of the flap, the survival of the distal limb, and the survival of the skin graft at the flap donor site were observed. Computed tomography angiography (CTA) was performed to observe the patency of the proximal and distal anastomotic arteries from 2 to 4 weeks after surgery. During follow-up, the texture of the flap, the survival of the grafted skin and the healing of the donor area were observed. Results: One patient (complete forearm disconnection) developed distal limb blood disorder on 5 days after surgery. CTA examination suggested embolization of the distal anastomosis of the flow-through artery. more muscle and skin and soft tissue necrosis of the distal limb showed in emergency exploration. So, amputation was performed ultimately. No vascular crisis occurred in the skin flaps of the remaining 10 patients, and all skin flaps, distal limbs and the skin grafts in flap donor sites survived well. Two to 4 weeks after surgery, the proximal and distal ends of the anastomosed arteries were good in the patency. Follow-up for 11-37 months, the flap texture was good, and all donor site wounds healed well. Conclusions: The use of anterolateral thigh flow-through chimeric perforator flap to repair upper limb complex tissue defects accompanied by main artery injury can improve the success rate of limb salvage, which can be promoted in clinical practice.
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Liang C, Zheng R, Liu X, Ma Q, Chen J, Shen Y. Predictive value of hematological parameters in cirrhotic patients with open umbilical hernia repair. Hernia 2024; 28:119-126. [PMID: 37848581 DOI: 10.1007/s10029-023-02908-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 10/01/2023] [Indexed: 10/19/2023]
Abstract
PURPOSE Patients with liver cirrhosis sometimes suffer from high recurrence rates and postoperative complications. We previously reported that platelet-related hematological parameters are associated with the outcomes after incisional herniorrhaphy, and aim to evaluate the predictive value of these criteria in cirrhotic patients undergoing open umbilical herniorrhaphy. METHODS This is a retrospective study. The data of 95 cirrhotic patients undergoing open umbilical herniorrhaphy were analyzed. Patients were grouped based on the recurrence and defined hematological values. Platelet-multiple-lymphocyte index (PLM), neutrophil-leukocyte ratio, lymphocyte-monocyte ratio, platelet-neutrophil ratio, systemic immune-inflammation index, and aspartate aminotransferase-leukocyte ratio values were calculated based on preoperative blood analyses. The outcomes were obtained from hospital records and follow-up calls to patients. RESULTS Using cutoff values acquired by the Youden Index, we found a PLM value < 27.9, and the history of inguinal herniorrhaphy were revealed to be statistically significant in the recurrence based on univariant and multivariant analyses (p < 0.05). We further divided patients into two groups based on the cutoff value of PLM and found that a PLM value < 27.9 was significantly associated with the recurrence of incisional hernias (p = 0.018) and the occurrence of postoperative foreign sensation (p = 0.044), and tended to result in other postoperative complications such as cardiopathy, respiratory infection, hypoproteinemia, and hepatic diseases (p = 0.089). CONCLUSION The preoperative hematological values, especially PLM, may indicate the outcomes in cirrhotic patients after open umbilical herniorrhaphy. Accurate identification of risks may alert the intraoperative and postoperative care for patients.
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Ma Q, Chen Z, Fang Y, Wei X, Wang N, Zhou X, Li S, Ying C. Development and validation of survival nomograms for patients with differentiated thyroid cancer with distant metastases: a SEER Program-based study. J Endocrinol Invest 2024; 47:115-129. [PMID: 37294407 DOI: 10.1007/s40618-023-02129-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 05/31/2023] [Indexed: 06/10/2023]
Abstract
BACKGROUND We aimed to develop a nomogram model of overall survival (OS) and cancer-specific survival (CSS) in patients with differentiated thyroid cancer with distant metastases, and to evaluate and validate the nomogram. Also, its prognostic value was compared with that of the 8th edition of the American Joint Committee on Cancer tumor-node-metastasis staging system (AJCC8SS). METHODS Patients with distant metastatic differentiated thyroid cancer (DMDTC) from 2004 to 2015 were selected from the Surveillance, Epidemiology, and End Results (SEER) Program to extract the clinical variables used for analysis. A total of 906 patients were divided into a training set (n = 634) and validation set (n = 272). OS and CSS were selected as the primary end point and secondary end point. LASSO regression analysis and multivariate Cox regression analysis were applied to screen variables for constructing OS and CSS nomograms for survival probability at 3, 5, and 10 years. Nomograms were evaluated and validated using the consistency index (C-index), time-dependent receiver operator characteristic (ROC) curves, area under the ROC curve, calibration curves, and decision curve analysis (DCA). The predictive survival of the nomogram was compared with that of AJCC8SS. Kaplan-Meier curves and log-rank tests were used to evaluate the risk-stratification ability OS and CSS nomograms. RESULTS CS and CSS nomograms included six independent predictors: age, marital status, type of surgical procedure, lymphadenectomy, radiotherapy, and T stage. The C-index for the OS nomogram was 0.7474 (95% CI = 0.7199-0.775), and that for the CSS nomogram was 0.7572 (0.7281-0.7862). The nomogram showed good agreement with the "ideal" calibration curve in the training set and validation sets. DCA confirmed that the survival probability predicted by the nomogram had high clinical predictive value. The nomogram could stratify patients more accurately, and showed more robust accuracy and predictive power, than AJCC8SS. CONCLUSIONS We established and validated prognostic nomograms for patients with DMDTC, which had significant clinical value compared with AJCC8SS.
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Chen M, Zhong Y, Harris E, Li J, Zheng Z, Chen H, Wu JS, Jarillo-Herrero P, Ma Q, Edgar JH, Lin X, Dai S. Van der Waals isotope heterostructures for engineering phonon polariton dispersions. Nat Commun 2023; 14:4782. [PMID: 37553366 PMCID: PMC10409777 DOI: 10.1038/s41467-023-40449-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 07/26/2023] [Indexed: 08/10/2023] Open
Abstract
Element isotopes are characterized by distinct atomic masses and nuclear spins, which can significantly influence material properties. Notably, however, isotopes in natural materials are homogenously distributed in space. Here, we propose a method to configure material properties by repositioning isotopes in engineered van der Waals (vdW) isotopic heterostructures. We showcase the properties of hexagonal boron nitride (hBN) isotopic heterostructures in engineering confined photon-lattice waves-hyperbolic phonon polaritons. By varying the composition, stacking order, and thicknesses of h10BN and h11BN building blocks, hyperbolic phonon polaritons can be engineered into a variety of energy-momentum dispersions. These confined and tailored polaritons are promising for various nanophotonic and thermal functionalities. Due to the universality and importance of isotopes, our vdW isotope heterostructuring method can be applied to engineer the properties of a broad range of materials.
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Angelopoulos V, Zhang XJ, Artemyev AV, Mourenas D, Tsai E, Wilkins C, Runov A, Liu J, Turner DL, Li W, Khurana K, Wirz RE, Sergeev VA, Meng X, Wu J, Hartinger MD, Raita T, Shen Y, An X, Shi X, Bashir MF, Shen X, Gan L, Qin M, Capannolo L, Ma Q, Russell CL, Masongsong EV, Caron R, He I, Iglesias L, Jha S, King J, Kumar S, Le K, Mao J, McDermott A, Nguyen K, Norris A, Palla A, Roosnovo A, Tam J, Xie E, Yap RC, Ye S, Young C, Adair LA, Shaffer C, Chung M, Cruce P, Lawson M, Leneman D, Allen M, Anderson M, Arreola-Zamora M, Artinger J, Asher J, Branchevsky D, Cliffe M, Colton K, Costello C, Depe D, Domae BW, Eldin S, Fitzgibbon L, Flemming A, Frederick DM, Gilbert A, Hesford B, Krieger R, Lian K, McKinney E, Miller JP, Pedersen C, Qu Z, Rozario R, Rubly M, Seaton R, Subramanian A, Sundin SR, Tan A, Thomlinson D, Turner W, Wing G, Wong C, Zarifian A. Energetic Electron Precipitation Driven by Electromagnetic Ion Cyclotron Waves from ELFIN's Low Altitude Perspective. SPACE SCIENCE REVIEWS 2023; 219:37. [PMID: 37448777 PMCID: PMC10335998 DOI: 10.1007/s11214-023-00984-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 06/28/2023] [Indexed: 07/15/2023]
Abstract
We review comprehensive observations of electromagnetic ion cyclotron (EMIC) wave-driven energetic electron precipitation using data collected by the energetic electron detector on the Electron Losses and Fields InvestigatioN (ELFIN) mission, two polar-orbiting low-altitude spinning CubeSats, measuring 50-5000 keV electrons with good pitch-angle and energy resolution. EMIC wave-driven precipitation exhibits a distinct signature in energy-spectrograms of the precipitating-to-trapped flux ratio: peaks at >0.5 MeV which are abrupt (bursty) (lasting ∼17 s, or Δ L ∼ 0.56 ) with significant substructure (occasionally down to sub-second timescale). We attribute the bursty nature of the precipitation to the spatial extent and structuredness of the wave field at the equator. Multiple ELFIN passes over the same MLT sector allow us to study the spatial and temporal evolution of the EMIC wave - electron interaction region. Case studies employing conjugate ground-based or equatorial observations of the EMIC waves reveal that the energy of moderate and strong precipitation at ELFIN approximately agrees with theoretical expectations for cyclotron resonant interactions in a cold plasma. Using multiple years of ELFIN data uniformly distributed in local time, we assemble a statistical database of ∼50 events of strong EMIC wave-driven precipitation. Most reside at L ∼ 5 - 7 at dusk, while a smaller subset exists at L ∼ 8 - 12 at post-midnight. The energies of the peak-precipitation ratio and of the half-peak precipitation ratio (our proxy for the minimum resonance energy) exhibit an L -shell dependence in good agreement with theoretical estimates based on prior statistical observations of EMIC wave power spectra. The precipitation ratio's spectral shape for the most intense events has an exponential falloff away from the peak (i.e., on either side of ∼ 1.45 MeV). It too agrees well with quasi-linear diffusion theory based on prior statistics of wave spectra. It should be noted though that this diffusive treatment likely includes effects from nonlinear resonant interactions (especially at high energies) and nonresonant effects from sharp wave packet edges (at low energies). Sub-MeV electron precipitation observed concurrently with strong EMIC wave-driven >1 MeV precipitation has a spectral shape that is consistent with efficient pitch-angle scattering down to ∼ 200-300 keV by much less intense higher frequency EMIC waves at dusk (where such waves are most frequent). At ∼100 keV, whistler-mode chorus may be implicated in concurrent precipitation. These results confirm the critical role of EMIC waves in driving relativistic electron losses. Nonlinear effects may abound and require further investigation.
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Yuan W, Zhang Y, Chen L, Jiang JN, Chen MM, Liu JY, Ma T, Ma Q, Cui MJ, Guo TJ, Wang XX, Dong YH, Ma J. [Association of body fat distribution with depression and social anxiety in children and adolescents: A cross-sectional study based on dual-energy X-ray detection]. BEIJING DA XUE XUE BAO. YI XUE BAN = JOURNAL OF PEKING UNIVERSITY. HEALTH SCIENCES 2023; 55:429-435. [PMID: 37291917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
OBJECTIVE To investigate the status of depression and social anxiety in children and adolescents, and to analyze the association between body fat distribution and depression, social anxiety in children and adolescents. METHODS A total of 1 412 children aged 7 to 18 years in Beijing were included by stratified cluster random sampling method. Body fat distribution, including total body fat percentage (total BF%), Android BF%, Gynoid BF% and Android-to-Gynoid fat ratio (AOI), were obtained by dual-energy X-ray absorption method. Depression and social anxiety were evaluated by Children Depression Inventory and Social Anxiety Scale for Children. Multivariate linear regression and restricted cubic spline analysis were used to estimate the linear and non-linear correlation between body fat distribution and depression and social anxiety. RESULTS 13.1% and 31.1% of the children and adolescents had depressive symptoms and social anxiety symptoms respectively, and the detection rate of depression and social anxiety in the boys and young groups was significantly lower than those in the girls and old groups. There was no significant linear correlation between total BF%, Android BF%, Gynoid BF%, AOI and depression and social anxiety in the children and adolescents. However, total BF% and Gynoid BF% had significant nonlinear correlation with depression, showing an inverted U-shaped curve relationship with the tangent points of 26.8% and 30.9%, respectively. In terms of the nonlinear association of total BF%, Android BF%, Gynoid BF% and AOI with depression and social anxiety, the change trends of the boys and girls, low age group and high age group were consistent. The overall anxiety risk HR of body fat distribution in the boys was significantly higher than that in the girls, and the risk HR of depression and social anxiety were significantly higher in the high age group than those in the low age group. CONCLUSION There was no significant linear correlation between body fat distribution and depression and social anxiety in children and adolescents. Total BF% and depression showed an inverted U-shaped curve, mainly manifested in Gynoid BF%, and this trend was consistent in different genders and different age groups. Maintaining children and adolescents' body fat distribution at an appropriate level is the future direction of the prevention and control of depression and social anxiety in children and adolescents.
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Wang HY, Qiu L, Ou CY, Lin ZQ, Huang ZD, Chen P, Ma Q, Lu YR, Ran H, Liu WB. An observational study on the safety of COVID-19 vaccination in patients with myasthenia gravis. Neurol Sci 2023:10.1007/s10072-023-06811-y. [PMID: 37160544 PMCID: PMC10166684 DOI: 10.1007/s10072-023-06811-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 04/10/2023] [Indexed: 05/11/2023]
Abstract
OBJECTIVE There is concern that the coronavirus disease (COVID-19) vaccine may trigger or worsen autoimmune diseases. The objective of this study was to determine the impacts of COVID-19 vaccination on symptom severity in patients with myasthenia gravis (MG). METHODS A total of 106 enrolled patients with MG who were vaccinated against COVID-19 were followed up, and a questionnaire was used to document in detail the exacerbation of muscle weakness after vaccination and all other uncomfortable reactions after vaccination. Demographic, clinical characteristics, medication, and vaccination data were collected by follow-up interview. The main observation outcome was whether the MG symptoms of patients were exacerbated. The definition of exacerbation is according to the subjective feeling of the patient or a 2-point increase in daily life myasthenia gravis activity score relative to before vaccination, within 30 days after vaccination. RESULTS Of 106 enrolled patients [median age (SD) 41.0 years, 38 (35.8%) men, 53 (50.0%) with generalized MG, 74 (69.8%) positive for acetylcholine receptor antibody, and 21 (19.8%) with accompanying thymoma], muscle weakness symptoms were stable in 102 (96.2%) patients before vaccine inoculation. Muscle weakness worsened in 10 (9.4%) people after vaccination, of which 8 patients reported slight symptom worsening that resolved quickly (within a few days). Two (1.9%) of patients showed serious symptom aggravation that required hospitalization. CONCLUSION Our results suggest that inactivated virus vaccines against COVID-19 may be safe for patients with MG whose condition is stable. Patients with generalized MG may be more likely to develop increased muscle weakness after vaccination.
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Shen J, Sun W, Wu K, Zhuang T, Lei J, Ma Q, Xiao L, Ge C. Loss- and gain-of-function analyses reveal the essential role of Cyp19a1 in ovarian determination of the red-eared slider turtle. Genetics 2023; 224:7083853. [PMID: 36947451 DOI: 10.1093/genetics/iyad041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 12/08/2022] [Accepted: 03/03/2023] [Indexed: 03/23/2023] Open
Abstract
Estrogen signaling exerts a decisive role in female sex determination and differentiation in chicken and fish. Aromatase encoded by Cyp19a1 is the key enzyme that catalyzes the conversion of androgen to estrogen. Correlative analyses implicate the potential involvement of aromatase in reptilian sexual development, however, the direct genetic evidence is lacking. Herein, we found that Cyp19a1 exhibited temperature-dependent sexually dimorphic expression, and located in the medullary somatic cells in early female embryos of the red-eared slider turtle (Trachemys scripta elegans), before the gonad is distinct. To determine the functional role of Cyp19a1 in turtle ovarian determination, we established loss- and gain-of function models through in ovo lentivirus-mediated genetic manipulation. At female producing temperature, inhibition of aromatase or knockdown of Cyp19a1 in turtle embryos resulted in female-to-male sex reversal, with the formation of a testis-like structure and a male distribution pattern of germ cells, as well as ectopic expression of male-specific markers (SOX9 and AMH) and disappearance of ovarian regulator FOXL2. On the contrary, overexpression of Cyp19a1 at male producing temperature led to male-to-female sex reversal. In conclusion, our results suggest that Cyp19a1 is both necessary and sufficient for ovarian determination in the red-eared slider turtle, establishing causality and a direct genetic link between aromatase and reptilian sex determination and differentiation.
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Boote C, Ma Q, Goh KL. Age-dependent mechanical properties of tail tendons in wild-type and mimecan gene-knockout mice - A preliminary study. J Mech Behav Biomed Mater 2023; 139:105672. [PMID: 36657194 DOI: 10.1016/j.jmbbm.2023.105672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 01/03/2023] [Accepted: 01/07/2023] [Indexed: 01/11/2023]
Abstract
Mimecan, or osteoglycin, belongs to the family of small leucine-rich proteoglycans. In connective tissues mimecan is implicated in the development and maintenance of normal collagen fibrillar organization. Since collagen fibrils are responsible for tissue reinforcement, the absence of mimecan could lead to abnormal tissue mechanical properties. Here, we carried out a preliminary investigation of possible changes in the mechanical properties of tendons in mice lacking a functional mimecan gene, as a function of age. Tail tendons were dissected from mimecan gene knockout (KO) and wild type (WT) mice at ages 1, 4 and 8 months and mechanical properties evaluated using a microtensile testing equipment. Mimecan gene knockout resulted in changes in tendon elasticity- and fracture-related properties. While tendons of WT mice exhibited enhanced mechanical properties with increasing age, this trend was notably attenuated in mimecan KO tendons, with the exception of fracture strain. When genotype and age were considered as cross factors, the diminution in the mechanical properties of mimecan KO tendons was significant for yield strength, modulus and fracture strength. This effect appeared to affect the mice at 4 month old. These preliminary results suggest that mimecan may have a role in regulating age-dependent mechanical function in mouse tail tendon.
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Wang R, Deng X, Ma Q, Ma F. Association between acrylamide exposure and sex hormones among premenopausal and postmenopausal women: NHANES, 2013-2016. J Endocrinol Invest 2023:10.1007/s40618-022-01976-3. [PMID: 36602706 DOI: 10.1007/s40618-022-01976-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 11/29/2022] [Indexed: 01/06/2023]
Abstract
PURPOSE Acrylamide (AA) is a potential carcinogen that mainly comes from fried, baked and roasted foods, and Hb adducts of AA (HbAA) and its metabolite glycidamide (HbGA) are the biomarkers of its exposure. Increasing evidence suggests that AA is associated with various hormone-related cancers. This study aims to explore the association of HbAA and HbGA with female serum sex hormone concentrations. METHODS 942 women from the National Health and Nutrition Examination Survey cycles (2013-2016) were included in this cross-sectional study. The associations between HbAA or HbGA or HbGA/HbAA and sex hormones were assessed by the multiple linear regression. Further stratified analyses were conducted to figure out the effects of menopausal status, BMI and smoking status on sex hormone levels. RESULTS Among all participants, 597 were premenopausal and 345 were postmenopausal. HbAA was positively associated with both two androgen indicators. Specifically, a ln-unit increase in HbAA was associated with 0.41 ng/dL higher ln(total testosterone, TT) (95% CI 0.00, 0.27) and 0.14 ng/dL higher ln(free testosterone) (95%CI 0.00, 0.28), respectively. However, HbGA concentrations had no association with sex hormones in the overall population. Additionally, HbGA/HbAA was negatively associated with TT and SHBG in the overall population as well as postmenopausal women. In stratified analysis, higher HbAA was associated with rising TT in postmenopausal women (β = 0.29, 95%CI 0.04, 0.53) and underweight/normal-weight women (β = 0.18, 95%CI 0.03, 0.33). Other indicators had no significant association detected in estradiol and sex hormone-binding globulin. CONCLUSION Our results revealed that HbAA was positively associated with androgen concentrations, especially in postmenopausal and BMI < 25 women.
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Chen L, Zhang Y, Chen MM, Ma T, Ma Q, Liu JY, Dong YH, Song Y, Ma J. [Prevalence of unhealthy lifestyle among children and adolescents of Han nationality in China]. ZHONGHUA XIN XUE GUAN BING ZA ZHI 2022; 50:1177-1185. [PMID: 36517438 DOI: 10.3760/cma.j.cn112148-20220826-00648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Objective: To explore the epidemiological characteristics and geographical distribution of unhealthy lifestyle among children and adolescents of Han nationality in China and obtain evidence for proposing the related strategies to improve the well-being of this population. Methods: Students aged 6-22 years old were selected from the Chinese National Survey on Students Constitution and Health in 2019. The prevalence of unhealthy lifestyles (physical inactivity, lack of outdoor activity, sedentary behavior, excessive screen time, sleep insufficiency, unhealthy eating behavior) between sex, residence, and age groups was calculated and compared. Multilevel logistic regression was used to explore the influencing factors of unhealthy lifestyle. Results: The prevalence of moderate-to-vigorous physical activity less than 1 h/d or 30 min/d were 82.06% and 54.69%, respectively. The prevalence of less than 2 h/d or 3 h/d of outdoor activities were 95.20% and 83.26%, respectively. The prevalence of more than 2 h/d or 3 h/d of sitting time were 50.64% and 31.92%, respectively. The prevalence of more than 2 h/d or 3 h/d of screen time were 42.02% and 27.79%, respectively. The prevalence of sleep insufficiency, excessive sugary beverages consumption (≥ 1 time/d), and insufficient consumption of eggs, milk, and breakfast (<7 d/week) were 66.49%, 20.97%, 83.36%, 70.71%, and 34.34%, respectively. The prevalence of severe sleep insufficiency, excessive sugary beverages consumption (≥ 3 times/d), and insufficient consumption of eggs, milk, and breakfast (≤2 d/week) were 27.77%, 8.21%, 47.21%, 32.36% and 9.73%, respectively. Conclusion: In 2019, unhealthy lifestyle is common among Han students aged 6-22 years in China. It is of importance to propose policies to strengthen the health education and initiatives to support healthy behaviors in Han children and adolescents. Jointly promotion on the creation of a healthy environment for Han children and adolescents, and formulation of targeted improvement measures in accordance with the epidemic characteristics in various regions are essential to improve the healthy lifestyle of this population.
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Ma T, Li YH, Chen MM, Ma Y, Gao D, Chen L, Ma Q, Zhang Y, Liu JY, Wang XX, Dong YH, Ma J. [Associations between early onset of puberty and obesity types in children: Based on both the cross-sectional study and cohort study]. BEIJING DA XUE XUE BAO. YI XUE BAN = JOURNAL OF PEKING UNIVERSITY. HEALTH SCIENCES 2022; 54. [PMID: 36241240 PMCID: PMC9568395 DOI: 10.19723/j.issn.1671-167x.2022.05.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
OBJECTIVE To explore and analyze the relationship between early onset of puberty and different types of obesity in children, by combining large sample cross-sectional survey data with long-term longitudinal cohort data, so as to provide clues for further clarifying the health hazards of early onset of puberty and obesity prevention and control. METHODS The research data were from the cross-sectional survey data of seven provinces(autonomous regions, municipalities) in China and the cohort data of adolescent development in Xiamen. The study first found the association between early onset of puberty and obesity by Logistic regression on the cross-sectional data, and then used Poisson regression to analyze the association between early puberty initiation and various types of obesity risk. RESULTS In the study, 43 137 and 1 266 children were included in the cross-sectional survey and cohort survey respectively. The cross-sectional study found that among the girls aged 10-13 years, compared with the girls of the same age who did not start puberty, the body mass index (BMI)-Z score of the girls in the puberty start group was 0.5-0.8 higher, and the waist circumference Z score was 0.4-0.7 higher, and the risk of various types of obesity was higher. At the same time, the early onset of puberty was positively correlated with simple obesity, central obesity and compound obesity, the OR (95%CI) were 1.86 (1.42-2.44), 1.95 (1.65-2.32) and 1.86 (1.41-2.45), respectively. No significant association was found in boys. According to the cohort data, in girls, the risk of simple obesity was 6.00 times [RR (95%CI): 6.00 (1.07-33.60)], the risk of central obesity was 3.30 times [RR (95%CI): 3.30 (1.22-8.92)], and the risk of compound obesity was 5.76 times [RR (95%CI): 5.76 (1.03-32.30)], compared with the group without early puberty initiation, while no association between early puberty initiation and obesity was found in boys. CONCLUSION Based on the cross-sectional survey and longitudinal cohort survey, it is confirmed that the early onset of puberty in girls may increase the risk of simple obesity, central obesity and compound obesity, while there is no significant correlation between puberty onset and obesity in boys.
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Claudepierre SG, Ma Q, Bortnik J. Quantifying Radiation Belt Electron Loss Processes at L < 4. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2022; 127:e2022JA030756. [PMID: 37034821 PMCID: PMC10078220 DOI: 10.1029/2022ja030756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 09/13/2022] [Accepted: 09/28/2022] [Indexed: 06/19/2023]
Abstract
We present a comprehensive analysis of the processes that lead to quasilinear pitch-angle-scattering loss of electrons from the L < 4 region of the Earth's inner magnetosphere during geomagnetically quiet times. We consider scattering via Coulomb collisions, hiss waves, lightning-generated whistler (LGW) waves, waves from ground-based very-low-frequency (VLF) transmitters, and electromagnetic ion cyclotron (EMIC) waves. The amplitude, frequency, and wave normal angle spectra of these waves are parameterized with empirical wave models, which are then used to compute pitch-angle diffusion coefficients. From these coefficients, we estimate the decay timescales, or lifetimes, of 30 keV to 4 MeV electrons and compare the results with timescales obtained from in-situ observations. We demonstrate good quantitative agreement between the two over most of the L and energy range under investigation. Our analysis suggests that the electron decay timescales are very sensitive to the choice of plasmaspheric density model. At L < 2, where our theoretical lifetimes do not agree well with the observations, we show that including Coulomb energy drag (ionization energy loss) in our calculations significantly improves the quantitative agreement with the observed decay timescales. We also use an accurate model of the geomagnetic field to provide an estimate of the effect that the drift-loss cone has on the theoretically calculated electron lifetimes, which are usually obtained using an axisymmetric dipole field.
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Zhong D, Meng F, Zhang L, Ma Q, Liu X, Wang X, Yang X. EP08.02-169 Research of Aumolertinib Combined with Bevacizumab for Advanced NSCLC Lung Cancer with EGFR Sensitive Mutation. J Thorac Oncol 2022. [DOI: 10.1016/j.jtho.2022.07.852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Johnson P, Bailey A, Milloy N, Clayton E, Quek R, Ma Q. 634P Real-world (RW) health-related quality of life (QoL) in patients (pts) with follicular lymphoma (FL): Comparisons by line of therapy (LOT) and region (Europe vs United States (US)). Ann Oncol 2022. [DOI: 10.1016/j.annonc.2022.07.760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Zhang S, Ma Q, Wu X, Chen P. LncRNA HOTTIP PROMOTES OVARIAN CANCER CELL INVASION AND METASTASIS BY STABILIZING HIF-1α IN THE ANOXIC CELLULAR MICROENVIRONMENT. ACTA ENDOCRINOLOGICA (BUCHAREST, ROMANIA : 2005) 2022; 18:263-270. [PMID: 36699159 PMCID: PMC9867806 DOI: 10.4183/aeb.2022.263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Background The high recurrence rate and low survival rate of ovarian cancer (OC) patients are closely related to an anoxic environment. We aim to study the mechanism of long non-coding RNA (lncRNA) HOXA transcript at the distal tip (HOTTIP) on hypoxia ovarian cancer cells (OCC) and its mechanism was investigated. Methods Knockdown and overexpression of HOTTIP in human OCC (SKOV-3, OVCAR3) were performed. The expression levels of HOTTIP and HIF-1α were monitored by qRT-PCR and WB. Transwell was conducted to validate the cell migration and invasion. ELISA was performed to calculate VEGF concentration in cells. Cell viability was monitored by CCK-8. Cell apoptosis and cycle were tested by flow cytometry. RNA pull-down was used to analyze the interaction between HIF-1α and HOTTIP. Results HOTTIP was highly expressed in OCC. After HOTTIP knockdown, HIF-1α expression and VEGF concentration in OCC were decreased. Cell migration, invasion, and cell viability were decreased. Cell apoptosis rate and G0/G1 phase cells were increased. RNA pull-down indicated a direct interaction between HIF-1α and HOTTIP. Conclusions HOTTIP formed a positive feedback loop with HIF-1α to promote the development and metastasis of hypoxia ovarian cancer. This study provided theoretical support for the development of new OC treatment strategies.
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Liu S, Liao L, Wei W, Liang Y, Xu J, Cao L, Li S, Li L, Meng L, Qian J, Zang Q, Wang L, Xu S, Cai J, Yan N, Ma Q, Zhao N, Chen R, Hu G, Liu J, Liu X, Ming T, Li L, Sun Y, Zeng L, Li G, Yao D, Xu G, Gong X, Gao X. Development and application of limiter Langmuir probe array in EAST. FUSION ENGINEERING AND DESIGN 2022. [DOI: 10.1016/j.fusengdes.2022.113162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Ma Q, Jia HY, Chang QL, Wang YD, Liang Y, Wang D, Zhang RR, Jiao YH. [Clinical characteristics and whole exome sequencing results of patients with Möbius syndrome]. [ZHONGHUA YAN KE ZA ZHI] CHINESE JOURNAL OF OPHTHALMOLOGY 2022; 58:441-447. [PMID: 35692026 DOI: 10.3760/cma.j.cn112142-20220314-00108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Objective: To analyze the clinical characteristics of patients with Möbius syndrome (MBS) and to explore likely pathogenic genes. Methods: Cross-sectional study. The study enrolled 18 sporadic MBS patients who visited the Eye Center of Beijing Tongren Hospital Affiliated to Capital Medical University from July 2018 to December 2021. All patients completed the general information questionnaire and underwent detailed ophthalmic examinations and general physical examinations. Seventeen patients received MRI examination of cranial nerves and the orbit. The peripheral venous blood of all patients and their nuclear family members was collected, the genomic DNA was extracted, and the pathogenic gene variations that may lead to MBS were identified by whole exome sequencing and bioinformatics analysis. Results: Among the 18 patients, there were 8 males and 10 females, and the age was (4.5±4.0) years (range, 8 months to 17 years). All patients showed congenital, bilateral or unilateral abduction deficit and facial weakness, which met the minimum diagnostic criteria of MBS. Among them, bilateral abduction deficit (16/18) and bilateral facial weakness (15/18) were more common. Nine patients were orthotopic in primary position, eight presented with esotropia, and one showed hypotropia. All patients had ametropia, of which 4 patients were diagnosed as amblyopia. Fifteen patients were also accompanied by other multiple congenital malformations, mainly characterized by abnormal development of glossopharynx (14/18) and limbs (5/18), and 7 patients were also accompanied by motor retardation. In addition, 9 patients had intrauterine exposure to adverse factors. Among the 17 patients who underwent MRI, 15 patients had bilateral hypoplasia of the abducens nerve, two had unilateral hypoplasia of the abducens nerve, 14 showed bilateral hypoplasia of the facial nerve, and three showed hypoplasia of the left facial nerve. Besides, some patients were also accompanied by hypoplasia of other cranial nerves, mainly the glossopharyngeal nerve and the hypoglossal nerve. No definite pathogenic variations were found by whole exome sequencing and bioinformatics analysis. Conclusions: The main clinical features of MBS were congenital abduction deficit and facial weakness, with complicated manifestations and variable severity. MRI showed absence or thinning of the abducens nerve and the facial nerve. The results of MRI can be used as a supplement to the diagnostic criteria of MBS. The mutation detection rate of MBS was low, and half of patients had exposure to adverse factors during pregnancy, suggesting that there was a multifactorial pathogenic mechanism in MBS.
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Eresen A, Sun C, Zhou K, Shangguan J, Wang B, Pan L, Hu S, Tran R, Ma Q, Yang J, Eresen A, Abi-Jaoudeh N, Zhang Z, Yaghmai V. Abstract No. 265 Differentiation of irreversible electroporation regions through interpretation of MRI texture. J Vasc Interv Radiol 2022. [DOI: 10.1016/j.jvir.2022.03.346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Bernhardt PA, Hua M, Bortnik J, Ma Q, Verronen PT, McCarthy MP, Hampton DL, Golkowski M, Cohen MB, Richardson DK, Howarth AD, James HG, Meredith NP. Active Precipitation of Radiation Belt Electrons Using Rocket Exhaust Driven Amplification (REDA) of Man-Made Whistlers. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2022; 127:e2022JA030358. [PMID: 35860435 PMCID: PMC9285445 DOI: 10.1029/2022ja030358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/27/2022] [Accepted: 05/16/2022] [Indexed: 06/15/2023]
Abstract
Ground-based very low frequency (VLF) transmitters located around the world generate signals that leak through the bottom side of the ionosphere in the form of whistler mode waves. Wave and particle measurements on satellites have observed that these man-made VLF waves can be strong enough to scatter trapped energetic electrons into low pitch angle orbits, causing loss by absorption in the lower atmosphere. This precipitation loss process is greatly enhanced by intentional amplification of the whistler waves using a newly discovered process called rocket exhaust driven amplification (REDA). Satellite measurements of REDA have shown between 30 and 50 dB intensification of VLF waves in space using a 60 s burn of the 150 g/s thruster on the Cygnus satellite that services the International Space Station. This controlled amplification process is adequate to deplete the energetic particle population on the affected field lines in a few minutes rather than the multi-day period it would take naturally. Numerical simulations of the pitch angle diffusion for radiation belt particles use the UCLA quasi-linear Fokker Planck model to assess the impact of REDA on radiation belt remediation of newly injected energetic electrons. The simulated precipitation fluxes of energetic electrons are applied to models of D-region electron density and bremsstrahlung X-rays for predictions of the modified environment that can be observed with satellite and ground-based sensors.
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Eresen A, Sun C, Zhou K, Shangguan J, Wang B, Pan L, Hu S, Tran R, Ma Q, Yang J, Nouizi F, Abi-Jaoudeh N, Zhang Z, Yaghmai V. Abstract No. 339 Correlation of histological tumor biomarkers with multivariable MRI texture model. J Vasc Interv Radiol 2022. [DOI: 10.1016/j.jvir.2022.03.420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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