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tRNA^(Glu)-derived fragments from embryonic extracellular vesicles modulate bovine embryo hatching
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作者 Yuan Fan Krishna Chaitanya Pavani +2 位作者 Katrien Smits Ann Van Soom Luc Peelman 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第4期1559-1566,共8页
Transfer RNA-derived small RNAs(tsRNAs)have been shown to be involved in early embryo development and repression of endogenous retroelements in embryos and stem cells.However,it is unknown whether tsRNAs also regulate... Transfer RNA-derived small RNAs(tsRNAs)have been shown to be involved in early embryo development and repression of endogenous retroelements in embryos and stem cells.However,it is unknown whether tsRNAs also regulate embryo hatching.In this study,we mined the sequencing data of a previous experiment in which we demonstrated that the microRNA(miRNA)cargo of preimplantation embryonic extracellular vesicles(EVs)influences embryo development.We thus profiled the tsRNA cargo of EVs secreted by blastocysts and non-blastocysts.The majority of tsRNAs was identified as tRNA halves originating from the 5'ends of tRNAs.Among the 148 differentially expressed tsRNAs,the 19 nt tRNA fragment(tRF)tDR-14:32-Glu-CTC-1 was found to be significantly up-regulated in EVs derived from non-blastocysts.RT-qPCR assays confirmed its significant up-regulation in non-blastocyst embryos and their conditioned medium compared to the blastocyst group(P<0.05).Inhibition of tDR-14:32-Glu-CTC-1 by supplementing antagomirs to the conditioned medium improved embryo hatching(P<0.05).Transcriptomic analysis of embryos treated with tDR-14:32-Glu-CTC-1 antagomirs further showed differential expression of genes that are associated with embryo hatching and implantation.In summary,tDR-14:32-Glu-CTC-1 is up-regulated in non-blastocyst embryos and their secretions,and inhibition of tDR-14:32-Glu-CTC-1 promotes embryo hatching,while influencing embryo implantation-related genes and pathways.These results indicate that embryonic EVs containing specific tRFs may regulate preimplantation embryo development. 展开更多
关键词 EMBRYO Extracellular vesicles HATCHING tRNA fragments ts RNAs
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Double casing warhead with sandwiched charge:The axial distribution of fragments velocities
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作者 Ping Ye Yongxiang Dong +5 位作者 Qitian Sun Peizhuo Shi Wang Yao Yongnan Li Yujing Li Mingze Li 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第4期201-216,共16页
The double casing warhead with sandwiched charge is a novel fragmentation warhead that can produce two groups of fragments with different velocity,and the previous work has presented a calculation formula to determine... The double casing warhead with sandwiched charge is a novel fragmentation warhead that can produce two groups of fragments with different velocity,and the previous work has presented a calculation formula to determine the maximum fragment velocity.The current work builds on the published formula to further develop a formula for calculating the axial distribution characteristics of the fragment velocity.For this type of warhead,the simulation of the dispersion characteristics of the detonation products at different positions shows that the detonation products at the ends have a much larger axial velocity than those in the middle,and the detonation products have a greater axial dispersion velocity when they are closer to the central axis.The loading process and the fragment velocity vary with the axial position for both casing layers,and the total velocity of the fragments is the vector sum of the radial velocity and the axial velocity.At the same axial position,the acceleration time of the inner casing is greater than that of the outer casing.For the same casing,the fragments generated at the ends have a longer acceleration time than the fragments from the middle.The proposed formula is validated with the X-ray radiography results of the four warheads previously tested experimentally and the 3D smoothedparticle hydrodynamics numerical simulation results of several series of new warheads with different configurations.The formula can accurately and reliably calculate the fragment velocity when the lengthto-diameter ratio of the charge is greater than 1.5 and the thickness of the casing is less than 20%its inner radius.This work thus provides a key reference for the theoretical analysis and the design of warheads with multiple casings. 展开更多
关键词 Double casing warhead Sandwiched charge Fragment velocity Rarefaction wave Gurney formula Explosive loading
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Exploring the regulatory mechanism of tRNA-derived fragments 36 in acute pancreatitis based on small RNA sequencing and experiments 被引量:1
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作者 Xi-Rui Fan Yun Huang +4 位作者 Yu Su Si-Jin Chen Yu-Lu Zhang Wei-Kang Huang Hui Wang 《World Journal of Gastroenterology》 SCIE CAS 2023年第30期4642-4656,共15页
BACKGROUND Acute pancreatitis(AP)is a disease featuring acute inflammation of the pancreas and histological destruction of acinar cells.Approximately 20%of AP patients progress to moderately severe or severe pancreati... BACKGROUND Acute pancreatitis(AP)is a disease featuring acute inflammation of the pancreas and histological destruction of acinar cells.Approximately 20%of AP patients progress to moderately severe or severe pancreatitis,with a case fatality rate of up to 30%.However,a single indicator that can serve as the gold standard for prognostic prediction has not been discovered.Therefore,gaining deeper insights into the underlying mechanism of AP progression and the evolution of the disease and exploring effective biomarkers are important for early diagnosis,progression evaluation,and precise treatment of AP.AIM To determine the regulatory mechanisms of tRNA-derived fragments(tRFs)in AP based on small RNA sequencing and experiments.METHODS Small RNA sequencing and functional enrichment analyses were performed to identify key tRFs and the potential mechanisms in AP.Reverse transcription quantitative polymerase chain reaction(RT-qPCR)was conducted to determine tRF expression.AP cell and mouse models were created to investigate the role of tRF36 in AP progression.Lipase,amylase,and cytokine levels were assayed to examine AP progression.Ferritin expression,reactive oxygen species,malondialdehyde,and ferric ion levels were assayed to evaluate cellular ferroptosis.RNA pull down assays and methylated RNA immunoprecipitation were performed to explore the molecular mechanisms.RESULTS RT-qPCR results showed that tRF36 was significantly upregulated in the serum of AP patients,compared to healthy controls.Functional enrichment analysis indicated that target genes of tRF36 were involved in ferroptosisrelated pathways,including the Hippo signaling pathway and ion transport.Moreover,the occurrence of pancreatic cell ferroptosis was detected in AP cells and mouse models.The results of interference experiments and AP cell models suggested that tRF-36 could promote AP progression through the regulation of ferroptosis.Furthermore,ferroptosis gene microarray,database prediction,and immunoprecipitation suggested that tRF-36 accelerated the progression of AP by recruiting insulin-like growth factor 2 mRNA binding protein 3(IGF2BP3)to the p53 mRNA m6A modification site by binding to IGF2BP3,which enhanced p53 mRNA stability and promoted the ferroptosis of pancreatic follicle cells.CONCLUSION In conclusion,regulation of nuclear pre-mRNA domain-containing protein 1B promoted AP development by regulating the ferroptosis of pancreatic cells,thereby acting as a prospective therapeutic target for AP.In addition,this study provided a basis for understanding the regulatory mechanisms of tRFs in AP. 展开更多
关键词 Acute pancreatitis tRNA-derived fragments tRNA-derived fragments 36 Mouse models Ferroptosis Reverse transcription quantitative polymerase chain reaction
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Debris cloud structure and hazardous fragments distribution under hypervelocity yaw impact
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作者 Chenyang Wu Qi-Guang He +2 位作者 Xiaowei Chen Chunbo Zhang Zebin Shen 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第9期169-183,共15页
This study investigates how the debris cloud structure and hazardous fragment distribution vary with attack angle by simulating a circular cylinder projectile hypervelocity impinging on a thin plate using the finite e... This study investigates how the debris cloud structure and hazardous fragment distribution vary with attack angle by simulating a circular cylinder projectile hypervelocity impinging on a thin plate using the finite element-smoothed particle hydrodynamics(FE-SPH)adaptive method.Based on the comparison and analysis of the experimental and simulation results,the FE-SPH adaptive method was applied to address the hypervelocity yaw impact problem,and the variation law of the debris cloud structure with the attack angle was obtained.The screening criterion of the hazardous fragment at yaw impact is given by analyzing the debris formation obtained by the FE-SPH adaptive method,and the distribution characteristics of hazardous fragments and their relationship with the attack angle are given.Moreover,the velocity space was used to evaluate the distribution range and damage capability of asymmetric hazardous fragments.The maximum velocity angle was extended from fully symmetrical working conditions to asymmetrical cases to describe the asymmetrical debris cloud distribution range.In this range,the energy density was calculated to quantitatively analyze how much damage hazardous fragments inflict on the rear plate.The results showed that the number of hazardous fragments generated by the case near the 35°attack angle was the largest,the distribution range was the smallest,and the energy density was the largest.These results suggest that in this case,debris cloud generated by the impact had the strongest damage to the rear plate. 展开更多
关键词 Debris cloud Hypervelocity yaw impact FE-SPH adaptive method Velocity space Hazardous fragments distribution
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Relationships between distribution characteristics of ceramic fragments and anti-penetration performance of ceramic composite bulletproof insert plates 被引量:1
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作者 Wen-hao Yu Wei-ping Li +3 位作者 Yi-fan Shangguan Xin-yang Ji Tian Ma Guo-qing Wu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第1期103-110,共8页
Through quantitative statistics and morphological characterization of ceramic fragments for ceramic composite bulletproof insert plates(CCBIPs),distribution characteristics of ceramic fragments within a specific size ... Through quantitative statistics and morphological characterization of ceramic fragments for ceramic composite bulletproof insert plates(CCBIPs),distribution characteristics of ceramic fragments within a specific size range were analyzed for different Armor Piercing Incendiary(API)and shot times.To quantitatively evaluate the effect of energy absorption for ceramic plates,a model of energy absorption during penetration for CCBIPs was established based on statistics of the size distribution of ceramic fragments(SDCF).Variation in the SDCF and its influence on energy absorption for CCBIPs were investigated.The results indicate that the distribution feature of ceramic fragments in the range of 0.25-2.25 mm is Gaussian distribution.Compared with Type 56 of API(56-API),ceramic fragments formed by 53-API with higher kinetic energy possess more quantity and more concentrated distribution,whose average equivalence size decreases by 6.5%,corresponding to increasing by 83.9%of estimated energy absorption.Besides,the ability of CCBIPs to resist the third shot is significantly weakened,whose estimated energy absorption decreases by 58.8%compared with the first shot.More concentrated distribution and fewer fragments are formed after the third shot,the average equivalence size of ceramic fragments increases by 6.9%,which may attribute to the micro-cracks induced by the previous two shots. 展开更多
关键词 Bulletproof insert plate Ceramic fragment Statistic Energy absorption Anti-penetration performance
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SPAGINS:semiempirical parameterization for fragments in gamma-induced nuclear spallation
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作者 Hui‑Ling Wei Meng‑Die Zhou +8 位作者 Pu Jiao Yu‑Ting Wang Jie Pu Kai‑Xuan Cheng Ya‑Fei Guo Chun‑Yuan Qiao Gong‑Tao Fan Hong‑Wei Wang Chun‑Wang Ma 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第12期112-122,共11页
From the empirical phenomena of fragment distributions in nuclear spallation reactions,semiempirical formulas named SPAGINS were constructed to predict fragment cross-sections in high-energyγ-induced nuclear spallati... From the empirical phenomena of fragment distributions in nuclear spallation reactions,semiempirical formulas named SPAGINS were constructed to predict fragment cross-sections in high-energyγ-induced nuclear spallation reactions(PNSR).In constructing the SPAGINS formulas,theoretical models,including the TALYS toolkit,SPACS,and Rudstam formulas,were employed to study the general phenomenon of fragment distributions in PNSR with incident energies ranging from 100 to 1000 MeV.Considering the primary characteristics of PNSR,the SPAGINS formulas modify the EPAX and SPACS formulas and efficiently reproduce the measured data.The SPAGINS formulas provide a new and effective tool for predicting fragment production in PNSR. 展开更多
关键词 High-energy gamma-rays Spallation reaction Fragment cross-section Empirical formula EPAX SPACS TALYS
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Lead spall velocity of fragments of ultra-high-performance concrete slabs under partially embedded cylindrical charge-induced explosion
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作者 Yi Fan Li Chen +2 位作者 Heng-bo Xiang Qin Fang Fang-yu Han 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第5期50-59,共10页
When an explosion occurs close to or partially within the face of a concrete structure, fragments are rapidly launched from the opposite face of the structure owing to concrete spalling, posing a significant risk to n... When an explosion occurs close to or partially within the face of a concrete structure, fragments are rapidly launched from the opposite face of the structure owing to concrete spalling, posing a significant risk to nearby personnel and equipment. To study the lead fragment velocity of ultra-high-performance concrete(UHPC), partially embedded explosion experiments were performed on UHPC slabs of limited thickness using a cylindrical trinitrotoluene charge. The launch angles and velocities of the resulting fragments were the determined using images collected by high-speed camera to document the concrete spalling and fragment launching process. The results showed that UHPC slabs without fiber reinforcement had a fragment velocity distribution of 0-118.3 m/s, which are largely identical to that for a normal-strength concrete(NSC) slab. In addition, the fragment velocity was negatively correlated to the angle between the velocity vector and vertical direction. An empirical Eq. for the lead spall velocity of UHPC and NSC slabs was then proposed based on a large volume of existing experimental data. 展开更多
关键词 Ultra-high-performance concrete Reinforced concrete slabs Explosion Fragment velocity Blast resistance
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Isolating the Mutator Transposable Element Insertional Mutant Gene mio16 of Maize Using Double SelectedAmplification of Insertion Flanking Fragments (DSAIFF)
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作者 ZHONG Wen-juan ZHANGMei-dong +4 位作者 YANG Liu-qi WANG Ming-chun ZHENG Yong-lian YANG Wen-peng GAO You-jun 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第10期1592-1600,共9页
Mutator transposable element (Mu) has been used as an effective tool to clone maize (Zea mays L.) genes. One opaque endosperm mutant (miol6) was identified in a pool of Mu inserted mutants. A modified method, te... Mutator transposable element (Mu) has been used as an effective tool to clone maize (Zea mays L.) genes. One opaque endosperm mutant (miol6) was identified in a pool of Mu inserted mutants. A modified method, termed the double selected amplification of insertion flanking fragments (DSAIFF), was employed to isolate the Mu flanking fragments (MFFs) of miol6. The target site duplications (TSDs) isolated from the Msp I and Mse I digested MFFs had a same 9-bp sequence and were confirmed to be the flanking sequence of one identically inserted gene. Co-segregation analysis suggested that the MFFs were associated with the mutant opaque endosperm, and miol6 was mapped in silico onto the physical position ranged from 229 965 021 to 229 965 409 bp of the maize chromosome 4.09 bin. The full-length cDNA of the wild-type gene was obtained by an RT-PCR primer-scanning technique, and Mio16 was found to putatively encode a homolog of the Arabidopsis MAP3K delta-1 protein kinase. RT-PCR result the mRNA expression of miol6 region anchored by primers Mu20 and af276 was not interrupted by Mu insertion. Further researches will be done to elucidate how the expression of miol6 is alternated by Mu insertion. 展开更多
关键词 maize (Zea mays L.) Mutator (Mu) transposable element Mu flanking fragments (MFFs) double selected amplification of insertion flanking fragments (DSAIFF) miol6
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Projected area and drag coefficient of high velocity irregular fragments that rotate or tumble 被引量:4
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作者 John F. Moxnes 0yvind Fr0 yland +4 位作者 Ivar J. 0ye Tom I. Brate Eva Friis Gard 0degardstuen Tallak H. Risdal 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2017年第4期269-280,共12页
3 degrees of freedom(DOF)exterior ballistic computer models are used in fragment studies to calculate individual trajectories of each fragment based on drag coefficient and the projected(presented)area in the directio... 3 degrees of freedom(DOF)exterior ballistic computer models are used in fragment studies to calculate individual trajectories of each fragment based on drag coefficient and the projected(presented)area in the direction of velocity of center of mass.The expectation of a randomly distributed projected area is commonly used for fragments that tumble(random rotation)during flight.We forecast a model where the expected drag coefficient is dependent of shape and Mach number.Rotation or tumbling only affects the expected projected area.Models of projected areas during tumbling and rotation are presented.An examination of the data by Mc Cleskey(1988)indicates that the volume of the fragment to the power of2/3 is a better parameter to characterize the drag coefficient of the fragments than the maximum projected area.Hydrocode simulations are used to verify results and to study projected area and drag coefficient of fragments. 展开更多
关键词 fragments Form factor MACH number Drag coefficient CAUCHY area TUMBLING
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Concurrent removal of intravitreal lens fragments after phacoemulsification with pars plana vitrectomy prevents development of retinal detachment 被引量:4
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作者 Kakarla V Chalam Ravi K Murthy +2 位作者 Joshua C Priluck Vijay Khetpal Shailesh K Gupta 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2015年第1期89-93,共5页
AIM: To evaluate the outcomes of "concurrent vitrectomy" to retrieve dislocated lens fragment during phacoemulsification.METHODS: In a retrospective, observational case series, data of patients who underwent... AIM: To evaluate the outcomes of "concurrent vitrectomy" to retrieve dislocated lens fragment during phacoemulsification.METHODS: In a retrospective, observational case series, data of patients who underwent "concurrent" pars plana vitrectomy(PPV) for dislocated lens fragments between the period 2000 and 2008 were reviewed. Data collected included patient demographics, pre-operative visual acuity, intra-operative occurrence of retinal breaks, duration of follow up, post-operative intraocular pressure, final best-corrected visual acuity(BCVA),presence of cystoid macular edema(CME) and occurrence of rhegmatogenous retinal detachment(RRD).· RESULTS: A total of 58 eyes of 58 patients were included in the study. At 12 mo the mean postoperative BCVA was log MAR 0.17(20/30) with a range of log MAR0 to 0.69(20/20 to 20/100), with 96.6%(56/58) of patients showing post- operative improvement in visual acuity(P =0.005). None of the patients developed postoperative retinal detachment, endophthalmitis or non-resolving uveitis at 12 mo.CONCLUSION: Our study results suggest concurrent PPV for retained lens fragments after cataract surgery is beneficial and may decrease the risk of glaucoma and prevent development of RRD. 展开更多
关键词 PHACOEMULSIFICATION dislocated lens fragments VITRECTOMY GLAUCOMA cystoid macular edema retinal detachment
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Isospin effects on intermediate mass fragments at intermediate energy-heavy ion collisions 被引量:5
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作者 Li Li Fang-Yuan Wang Ying-Xun Zhang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2022年第5期68-77,共10页
In this study,we investigated the isospin properties of intermediate mass fragments(IMFs)for the central collisions of^(112,124)Sn+^(112,124)Sn at a beam energy of50 MeV per nucleon using an improved quantum molecular... In this study,we investigated the isospin properties of intermediate mass fragments(IMFs)for the central collisions of^(112,124)Sn+^(112,124)Sn at a beam energy of50 MeV per nucleon using an improved quantum molecular dynamics model(ImQMD)coupled with a sequential decay model(GEMINI).Three observables were analyzed:(1)the average center-of-mass kinetic energy per nucleon<Ec.m./A>of fragments as a function of their charge number Z;(2)the average neutron number to proton number ratio(<N>/Z)of fragments with a given charge number Z as a function of their center-of-mass kinetic energy per nucleon(Ec.m./A);and(3)the average total neutron number to total proton number ratio(ΣN/ΣZ)and double ratio(DR(N/Z))of IMFs with Z=3-8 as a function of their center-of-mass kinetic energy per nucleon Ec.m./A.Our calculations revealed that the sensitivity of the isospin properties of IMFs relative to the stiffness of the symmetry energy remains even after sequential decay.By comparing the calculations ofΣN/ΣZ and DR(N/Z)with the data,it was found that the soft symmetry energy,i.e.,γ=0.5,is favored. 展开更多
关键词 Symmetryenergy Intermediatemass fragments Isospin effects
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Use of chondral fragments for one stage cartilage repair: A systematic review 被引量:5
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作者 Davide Edoardo Bonasia Antongiulio Marmotti +2 位作者 Federica Rosso Gianluca Collo Roberto Rossi 《World Journal of Orthopedics》 2015年第11期1006-1011,共6页
AIM: To investigate the state of the art regarding Cartilage Autograft Implantation System(CAIS) or Particulated Juvenile Allograft Cartilage(PJAC).METHODS: The authors searched the English literature regarding CAIS a... AIM: To investigate the state of the art regarding Cartilage Autograft Implantation System(CAIS) or Particulated Juvenile Allograft Cartilage(PJAC).METHODS: The authors searched the English literature regarding CAIS and PJAC. The search strategy was:(particulated cartilage) OR autologous cartilage fragments. All basic science articles were included. Clinical articles with less than 10 patients treated and less than 6 mo of follow-up were excluded. With these criteria, a total of 17 articles were available for the present review. RESULTS: PJAC and CAIS are relatively novel techniques for cartilage repair. Good basic science evidence was described to support the concept. Although the preliminary clinical reports show encouraging results, clinical data are still limited, especially for CAIS. The indications for both techniques need to be precisely defined(age of the patients, size of the lesion, and involvement of the subchondral bone), together with other debated issues. CONCLUSION: In conclusion, the authors can state that encouraging preliminary results are available for both techniques. However, further studies are necessary to precisely determine the indications, surgical techniques, and long term outcomes for PJAC and CAIS. 展开更多
关键词 CARTILAGE JUVENILE CHONDRAL fragments ADULT Particulated CARTILAGE
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Probiotical Cell Fragments (PCFs) as “Novel Nutraceutical Ingredients” 被引量:6
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作者 Nditange Shigwedha Liubov Sichel +1 位作者 Li Jia Lanwei Zhang 《Journal of Biosciences and Medicines》 2014年第3期43-55,共13页
Probiotical cell fragments (PCFs) are structural components of the probiotic cell lysate(s) and exhibit similar beneficial effects on the host as live probiotic bacteria. With cell fragment technology (CFT?), the stru... Probiotical cell fragments (PCFs) are structural components of the probiotic cell lysate(s) and exhibit similar beneficial effects on the host as live probiotic bacteria. With cell fragment technology (CFT?), the structural fragments are isolated and purified from live probiotic cells. While observed to be strain-dependent as in the case of live probiotics, orally administered PCFs demonstrated a broad spectrum of immune modulation functions;anti-allergy;anti-inflammation;anti-bacterial and anti-viral properties;anti-mutagenic;and radioprotective and detoxification abilities in humans and animals. The PCFs mechanisms of action include events of motifs of cell wall peptidoglycans, DNA motifs, nucleotide containing components, lipoteichoic acids (LPAs), surface layer (S-layer) proteins, and cytoplasmic proteins. Different immunological in vivo-in vitro tests have shown that PCFs, essentially, have the ability to stimulate the macrophages, and induce cytokines such as interleukins, tumor necrosis factors (TNFs), interferons (IFNs), and natural killer (NK) cells. PCFs may be used as ingredients for foods and beverages or as nutritional supplements with long term stability and shelf-life up to 5 years. PCFs may also be used as health restorative ingredients in cosmetic products. The outcome of probiotics CFT? stands as an advantage to the food and pharmaceutical industries, regarding the formulation of novel products with unadulterated sensory characteristics of origin. Hence, PCFs are being characterized here as “novel nutraceutical ingredients” for health maintenance in both humans and animals. 展开更多
关键词 Probiotical CELL fragments (PCFs) Paraprobiotics Immunobiotics IMMUNOMODULATOR NUTRACEUTICAL INGREDIENTS LACTIC Acid Bacteria (LAB)
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Estimation of projected surface area of irregularly shaped fragments 被引量:2
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作者 Elvedin Kljuno Alan Catovic 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2019年第2期198-209,共12页
The essence and the main contribution of this paper are consisted of the suggested novel method for estimation of a projected surface area of an irregularly shaped fragment, which represents a significant step toward ... The essence and the main contribution of this paper are consisted of the suggested novel method for estimation of a projected surface area of an irregularly shaped fragment, which represents a significant step toward a new method of an aerodynamic force estimation of a fragment motion through a resistive medium. The suggested method is to use a tri-axial ellipsoid that has a continuous surface(given as a mathematical function) to approximate an irregularly shaped fragment so that the fragment trajectory can be estimated faster taking into consideration that the aerodynamic force is proportional to a projected surface area of the fragment.During their motion, fragments can take any orientation relative to the velocity vector and aerodynamic force is proportional to a projected surface area of fragment perpendicular to the velocity vector,so it is necessary to have a method for correct estimation of the projected area in an arbitrary direction relatively to the fragment.The model was validated with analytical and CAD techniques, and verified using 3D model of a real fragment. The comparison of the projected surface area values for the fragment, obtained using the CAD tools and using our model, are generally in good agreement, This method represents a step toward modeling that does not require a CFD result for estimation of the aerodynamic force of irregularly shaped bodies. 展开更多
关键词 Projected area fragments TRAJECTORY
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A fast and accurate model for the creation of explosion fragments with improved fragment shape and dimensions 被引量:2
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作者 David Felix Ian Colwill Paul Harris 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2022年第2期159-169,共11页
Explosion models based on Finite Element Analysis(FEA)can be used to simulate how a warhead fragments.However their execution times are extensive.Active protection systems need to make very fast predictions,before a f... Explosion models based on Finite Element Analysis(FEA)can be used to simulate how a warhead fragments.However their execution times are extensive.Active protection systems need to make very fast predictions,before a fast attacking weapon hits the target.Fast execution times are also needed in real time simulations where the impact of many different computer models is being assessed.Hence,FEA explosion models are not appropriate for these real-time systems.The research presented in this paper delivers a fast simulation model based on Mott’s equation that calculates the number and weight of fragments created by an explosion.In addition,the size and shape of fragments,unavailable in Mott’s equation,are calculated using photographic evidence and a distribution of a fragment’s length to its width.The model also identifies the origin of fragments on the warhead’s casing.The results are verified against experimental data and a fast execution time is achieved using uncomplicated simulation steps.The developed model then can be made available for real-time simulation and fast computation. 展开更多
关键词 Distribution of fragments Fragment shape Real-time simulation Cylindrical explosion
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Definition, treatment and outcome of residual fragments in staghorn stones 被引量:2
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作者 Osman Ermis Bhaskar Somani +5 位作者 Thomas Reeves Selcuk Guven Pilar Laguna Pes Arun Chawla Padmaraj Hegde Jean de la Rosette 《Asian Journal of Urology》 CSCD 2020年第2期116-121,共6页
Technological advances in minimally invasive treatment of stone disease and its integration with concomitant clinical practice are amongst the most important achievements in urology.Despite the wealth of information a... Technological advances in minimally invasive treatment of stone disease and its integration with concomitant clinical practice are amongst the most important achievements in urology.Despite the wealth of information accumulated over the years and the richness of existing literature,the knowledge about the definition,treatment and outcomes of residual stone fragments after percutaneous nephrolithotomy(PNL)is still insufficient.Due to the high stone load a lot of patients with staghorn stones have residual fragments(RFs)after treatment with PNL,which depends on the size of tract,definition of stone free rate(SFR),timing of evaluation and the imaging used.No consensus exists on the imaging modality or their timing in the evaluation of possible RFs.The treatment of residual stones is apparently different depending on the facilities of the department and the preference of the surgeon,which includes active surveillance,shock wave lithotripsy(SWL),retrograde intrarenal surgery(RIRS)or a second look PNL. 展开更多
关键词 UROLITHIASIS Stone management Staghorn Percutaneous nephrolithotomy Residual fragments Staghorn stones
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Azimuthal distributions of final-state particles and fragments and transverse structure of emission source in high-energy nucleus-nucleus collisions 被引量:2
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作者 刘福虎 马引群 段麦英 《Chinese Physics B》 SCIE EI CAS CSCD 2005年第12期2458-2466,共9页
The azimuthal distributions of final-state particles and fragments produced in high-energy nucleus-nucleus collisions are described by a modified multisource ideal gas model which contains the expansions and movements... The azimuthal distributions of final-state particles and fragments produced in high-energy nucleus-nucleus collisions are described by a modified multisource ideal gas model which contains the expansions and movements of the emission sources. The transverse structures of the sources are given in the transverse plane by momentum components Px and Py, and described by parameters in the model. The results of the azimuthal distributions, calculated by the Monte Carlo method, are in good agreement with the experimental data in nucleus-nucleus collisions at high energies. 展开更多
关键词 high-energy nucleus-nucleus collisions final-state particles and fragments azimuthal distributions transverse structure of emission source
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Dynamic Response of Stiffened Plates with Holes Subjected to Shock Waves and Fragments 被引量:1
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作者 刘彦 张庆明 黄风雷 《Journal of Beijing Institute of Technology》 EI CAS 2004年第3期295-298,共4页
The power field of shock waves and fragments is analyzed and set up, and the damage modes of stiffened plates are put forward. According to the structural characters of the stiffened plates investigated and the proper... The power field of shock waves and fragments is analyzed and set up, and the damage modes of stiffened plates are put forward. According to the structural characters of the stiffened plates investigated and the properties of the shock waves and fragments, the experiments on the shock waves acting on the stiffened plates (penetrated and non-penetrated by fragments) are mainly conducted. The dynamic response rules of stiffened plates with holes under shock waves and fragments loading are obtained. The results show that the penetration of fragments into stiffened plates hardly affects their deformation produced by shock waves.. 展开更多
关键词 shock waves fragments stiffened plates dynamic response
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Potential Correlations between Unexplained Experimental Observables and Hot Projectile-Like Fragments in Primary Interactions above <i>E</i><sub>CM/<i>u</i></sub>≈ 150 MeV 被引量:2
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作者 Eberhard Ganssauge Wolfram Westmeier Reinhard Brandt 《World Journal of Nuclear Science and Technology》 2013年第4期155-161,共7页
An enhanced neutron production and an enhanced nuclear destruction due to secondary fragments have been observed in very thick targets irradiated with high energy ions. This enhancement is beyond theoretical calculati... An enhanced neutron production and an enhanced nuclear destruction due to secondary fragments have been observed in very thick targets irradiated with high energy ions. This enhancement is beyond theoretical calculations and it is an unresolved problem. It is observed only when primary ion interactions exceed an energy threshold (ECM/u ≈ 150 MeV). Investigations using nuclear emulsions for very high-energy nuclear reactions suggest that two distinctly different classes of relativistic projectile-like fragments are emitted in primary interactions: a “cool” channel with a temperature of (T(p)cool ≈ 10 MeV), and a “hot” channel with (T(p)hot ≈ 40 MeV. This second reaction class may induce the above mentioned enhanced reactions of secondary fragments, thus being responsible for unresolved problems. This assumption should be studied in further experiments. Nuclear interactions of secondary particles in thick targets are of interest, in particular in view of radiation protection needs for high energy and high intensity heavy ion accelerators. Many basic ideas of this paper go back to the late Professor E. Schopper (Frankfurt). 展开更多
关键词 Very High Energy PROJECTILE HOT PROJECTILE fragments Cool Target fragments Unresolved Problems
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Comment on concurrent removal of intravitreal lens fragments after phacoemulsification with pars plana vitrectomy prevents development of retinal detachment 被引量:1
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作者 Yu Cheol Kim 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2016年第6期935-936,共2页
I read with interest the article entitled "Concurrent removal of intravitreal lens fragments afterphacoemulsification with pars plana vitrectomy prevents development of retinal detachment" by Chalam et al . In this ... I read with interest the article entitled "Concurrent removal of intravitreal lens fragments afterphacoemulsification with pars plana vitrectomy prevents development of retinal detachment" by Chalam et al . In this study, none of the patients developed retinal detachment (RD) during the one-year follow-up after concurrent removal lens fragments following phacoemulsification with pars plana vitrectomy (PPV). The authors suggested that concurrent PPV for retained lens fragments after cataract surgery might prevent development of rhegmatogenous retinal detachment (RRD), because early PPV prevents development of intraocular inflammation and inhibits vitreous contraction, a common cause of retinal tears and detachment. 展开更多
关键词 RRD PPV Comment on concurrent removal of intravitreal lens fragments after phacoemulsification with pars plana vitrectomy prevents development of retinal detachment
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