Approximately 30%-40% of epilepsy patients do not respond well to adequate anti-seizure medications(ASMs),a condition known as pharmacoresistant epilepsy.The management of pharmacoresistant epilepsy remains an intract...Approximately 30%-40% of epilepsy patients do not respond well to adequate anti-seizure medications(ASMs),a condition known as pharmacoresistant epilepsy.The management of pharmacoresistant epilepsy remains an intractable issue in the clinic.Its early prediction is important for prevention and diagnosis.However,it still lacks effective predictors and approaches.Here,a classical model of pharmacoresistant temporal lobe epilepsy(TLE)was established to screen pharmacoresistant and pharmaco-responsive individuals by applying phenytoin to amygdaloid-kindled rats.Ictal electroencephalograms(EEGs)recorded before phenytoin treatment were analyzed.Based on ictal EEGs from pharmacoresistant and pharmaco-responsive rats,a convolutional neural network predictive model was constructed to predict pharmacoresistance,and achieved 78% prediction accuracy.We further found the ictal EEGs from pharmacoresistant rats have a lower gamma-band power,which was verified in seizure EEGs from pharmacoresistant TLE patients.Prospectively,therapies targeting the subiculum in those predicted as“pharmacoresistant”individual rats significantly reduced the subsequent occurrence of pharmacoresistance.These results demonstrate a new methodology to predict whether TLE individuals become resistant to ASMs in a classic pharmacoresistant TLE model.This may be of translational importance for the precise management of pharmacoresistant TLE.展开更多
Thinning of antenna arrays has been a popular topic for the last several decades.With increasing computational power,this optimization task acquired a new hue.This paper suggests a genetic algorithm as an instrument f...Thinning of antenna arrays has been a popular topic for the last several decades.With increasing computational power,this optimization task acquired a new hue.This paper suggests a genetic algorithm as an instrument for antenna array thinning.The algorithm with a deliberately chosen fitness function allows synthesizing thinned linear antenna arrays with low peak sidelobe level(SLL)while maintaining the half-power beamwidth(HPBW)of a full linear antenna array.Based on results from existing papers in the field and known approaches to antenna array thinning,a classification of thinning types is introduced.The optimal thinning type for a linear thinned antenna array is determined on the basis of a maximum attainable SLL.The effect of thinning coefficient on main directional pattern characteristics,such as peak SLL and HPBW,is discussed for a number of amplitude distributions.展开更多
To the Editor:Theoretically,autologous liver transplantation is posited as a treatment for patients experiencing traumatic liver rupture.How-ever,the procedural complexity and its infrequent application by the medical...To the Editor:Theoretically,autologous liver transplantation is posited as a treatment for patients experiencing traumatic liver rupture.How-ever,the procedural complexity and its infrequent application by the medical community have resulted in a lack of documented suc-cesses.This report presented the efficacious intervention in a pa-tient presenting with polytraumatic injuries involving the thoracic and abdominal regions,namely right-sided hemothorax,contusion and hematoma of the right lung,splenic rupture,lateral damage to the common bile duct,disruption of the left portal vein branch and left hepatic duct,incisions in the hepatic segments IV,V,VI,VII,and VIII,laceration of the right adrenal gland,rupture of the right hepatic venous trunk and retro-hepatic inferior vena cava(RHIVC),and pancreatic hematoma.展开更多
In insects,the number and specificity of antennal lobe glomeruli often reflect the number and diversity of expressed chemosensory genes,which are linked to its ecological niche and specific olfactory needs.The orienta...In insects,the number and specificity of antennal lobe glomeruli often reflect the number and diversity of expressed chemosensory genes,which are linked to its ecological niche and specific olfactory needs.The oriental armyworm,Mythimna separata,is an important and common lepidopteran pest of cereal crops.Given its reliance on the olfactory system for crucial behaviors,understanding the evolutionary potential of this system requires a thorough characterization of the anatomical structure of the primary olfactory center.Here,we systematically identified all antennal lobe glomeruli of M.separata based on synaptic antibody immunostaining and mass staining of the olfactory sensory neurons.A total of 69 glomeruli were identified in females and 65 in males,and an intuitive nomenclature based on glomerular positions was applied.Our findings uncovered some sex-specific glomeruli in this species.There were ten female-specific glomeruli and three male-specific glomeruli,except for the macroglomerular complex(MGC)units,with a notable observation that the female labial pit organ glomerulus was larger than its male counterpart.Additionally,we identified four antennal-lobe tracts(ALTs)and retrograde labeling from the calyx revealed that all glomeruli were innervated by the medial ALT projection neurons.The comparison of the olfactory system structures between M.separata and sympatric moths supports their evolutionary convergence in noctuid moths.These results collectively lay the foundation for future studies on olfactory processing in M.separata.展开更多
Neuroinflammation mediated by microglia and oxidative stress play pivotal roles in the development of chronic temporal lobe epilepsy(TLE).We postulated that kainic acid(KA)-Induced status epilepticus triggers microgli...Neuroinflammation mediated by microglia and oxidative stress play pivotal roles in the development of chronic temporal lobe epilepsy(TLE).We postulated that kainic acid(KA)-Induced status epilepticus triggers microglia-dependent inflammation,leading to neuronal damage,a lowered seizure threshold,and the emergence of spontaneous recurrent seizures(SRS).Extensive evidence from our laboratory suggests that dextromethorphan(DM),even in ultra-low doses,has anti-inflammatory and neuroprotective effects in many animal models of neurodegenerative disease.Our results showed that administration of DM(10 ng/kg per day;subcutaneously via osmotic minipump for 4 weeks)significantly mitigated the residual effects of KA,including the frequency of SRS and seizure susceptibility.In addition,DM-treated rats showed improved cognitive function and reduced hippocampal neuronal loss.We found suppressed microglial activation-mediated neuroinflammation and decreased expression of hippocampal gp91^(phox) and p47^(phox) proteins in KA-induced chronic TLE rats.Notably,even after discontinuation of DM treatment,ultra-low doses of DM continued to confer long-term anti-seizure and neuroprotective effects,which were attributed to the inhibition of microglial NADPH oxidase 2 as revealed by mechanistic studies.展开更多
Secondary epileptogenesis is characterized by increased epileptic susceptibility and a tendency to generate epileptiform activities outside the primary focus.It is one of the major resultants of pharmacoresistance and...Secondary epileptogenesis is characterized by increased epileptic susceptibility and a tendency to generate epileptiform activities outside the primary focus.It is one of the major resultants of pharmacoresistance and failure of surgical outcomes in epilepsy,but still lacks effective treatments.Here,we aimed to test the effects of low-frequency stimulation(LFS)at the subiculum for secondary epileptogenesis in a mouse model.Here,secondary epileptogenesis was simulated at regions both contralateral and ipsilateral to the primary focus by applying successive kindling stimuli.Mice kindled at the right CA3 showed higher seizure susceptibilities at both the contralateral CA3 and the ipsilateral entorhinal cortex and had accelerated kindling processes compared with naive mice.LFS at the ipsilateral subiculum during the primary kindling progress at the right CA3 effectively prevented secondary epileptogenesis at both the contralateral CA3 and the ipsilateral entorhinal cortex,characterized by decreased seizure susceptibilities and a retarded kindling process at those secondary foci.Only application along with the primary epileptogenesis was effective.Notably,the effects of LFS on secondary epileptogenesis were associated with its inhibitory effect at the secondary focus through interfering with the enhancement of synaptic connections between the primary and secondary foci.These results imply that LFS at the subiculum is an effective preventive strategy for extensive secondary epileptogenesis in temporal lobe epilepsy and present the subiculum as a target with potential translational importance.展开更多
Temporal lobe epilepsy is a multifactorial neurological dysfunction syndrome that is refractory,resistant to antiepileptic drugs,and has a high recurrence rate.The pathogenesis of temporal lobe epilepsy is complex and...Temporal lobe epilepsy is a multifactorial neurological dysfunction syndrome that is refractory,resistant to antiepileptic drugs,and has a high recurrence rate.The pathogenesis of temporal lobe epilepsy is complex and is not fully understood.Intracellular calcium dynamics have been implicated in temporal lobe epilepsy.However,the effect of fluctuating calcium activity in CA1 pyramidal neurons on temporal lobe epilepsy is unknown,and no longitudinal studies have investigated calcium activity in pyramidal neurons in the hippocampal CA1 and primary motor cortex M1 of freely moving mice.In this study,we used a multichannel fiber photometry system to continuously record calcium signals in CA1 and M1 during the temporal lobe epilepsy process.We found that calcium signals varied according to the grade of temporal lobe epilepsy episodes.In particular,cortical spreading depression,which has recently been frequently used to represent the continuously and substantially increased calcium signals,was found to correspond to complex and severe behavioral characteristics of temporal lobe epilepsy ranging from gradeⅡto gradeⅤ.However,vigorous calcium oscillations and highly synchronized calcium signals in CA1 and M1 were strongly related to convulsive motor seizures.Chemogenetic inhibition of pyramidal neurons in CA1 significantly attenuated the amplitudes of the calcium signals corresponding to gradeⅠepisodes.In addition,the latency of cortical spreading depression was prolonged,and the above-mentioned abnormal calcium signals in CA1 and M1 were also significantly reduced.Intriguingly,it was possible to rescue the altered intracellular calcium dynamics.Via simultaneous analysis of calcium signals and epileptic behaviors,we found that the progression of temporal lobe epilepsy was alleviated when specific calcium signals were reduced,and that the end-point behaviors of temporal lobe epilepsy were improved.Our results indicate that the calcium dynamic between CA1 and M1 may reflect specific epileptic behaviors corresponding to different grades.Furthermore,the selective regulation of abnormal calcium signals in CA1 pyramidal neurons appears to effectively alleviate temporal lobe epilepsy,thereby providing a potential molecular mechanism for a new temporal lobe epilepsy diagnosis and treatment strategy.展开更多
BACKGROUND In laparoscopic proximal gastrectomy(LPG),the prolapse of the hepatic left lateral lobe near the lesser curvature and esophageal hiatus can obstruct the field of vision and operation.Therefore,it is necessa...BACKGROUND In laparoscopic proximal gastrectomy(LPG),the prolapse of the hepatic left lateral lobe near the lesser curvature and esophageal hiatus can obstruct the field of vision and operation.Therefore,it is necessary to retract or obstruct the hepatic left lateral lobe to ensure a clear field of vision.AIM To investigate the safety and clinical efficacy of the modified hepatic left lateral lobe inversion technique for LPG.METHODS A retrospective analysis was conducted on the clinical data of 13 consecutive patients with early-stage upper gastric adenocarcinoma or adenocarcinoma of the esophagogastric junction treated with LPG from January to December 2023 at the Department of Gastrointestinal Surgery,Second Affiliated Hospital of Fujian Medical University.The modified hepatic left lateral lobe inversion technique was used to expose the surgical field in all patients,and short-term outcomes were observed.RESULTS In all 13 patients,the modified hepatic left lateral lobe inversion technique was successful during surgery without the need for re-retraction or alteration of the liver traction method.There were no instances of esophageal hiatus occlusion,eliminating the need for forceps to assist in exposure.There was no occurrence of intraoperative hepatic hemorrhage,hepatic vein injury,or hepatic congestion.No postoperative digestive complications of Clavien-Dindo grade≥II occurred wi-thin 30 days after surgery,except for a single case of pulmonary infection.Some patients experienced increases in alanine aminotransferase and aspartate aminotransferase levels on the first day after surgery,which significantly decreased by the third day and returned to normal by the seventh day after surgery.CONCLUSION The modified hepatic left lateral lobe inversion technique has demonstrated satisfactory results,offering ad-vantages in terms of facilitating surgical procedures,reducing surgical trauma,and protecting the liver.展开更多
BACKGROUND Gelastic seizure(GS)is a rare type of epilepsy that most commonly appears in patients with hypothalamic hamartoma.It is rarely associated with other types of brain damage.This particular type of epilepsy is...BACKGROUND Gelastic seizure(GS)is a rare type of epilepsy that most commonly appears in patients with hypothalamic hamartoma.It is rarely associated with other types of brain damage.This particular type of epilepsy is relatively rare and has few links to other brain lesions.Temporal lobe malacia is mostly caused by cerebral infarction or cerebral hemorrhage,which can lead to seizures.We report a case of GS in a woman with temporal lobe malacia which was reported for the first time in the literature.CASE SUMMARY A 73-year-old female,diagnosed case of GS,presented with repetitive stereotyped laughter a month prior to presentation,happening multiple times daily and with each time lasting for 5-15s.Electroencephalogram displayed a focal seizure seen in the right temporal region.Magnetic resonance imaging head with contrast showed a right temporal lobe malacia.The patient was started on levetiracetam daily.The patient indicated that they had fully recovered and were not experiencing any recurrent or stereotyped laughter during their daily routines.These results remained consistent even after a one-year follow-up period.CONCLUSION GS can be caused by temporal lobe malacia,which is an uncommon but potentially grave condition.The outcome of this present case exhibited the importance of the temporal lobe in the genesis of GS.展开更多
The performance of a newly designed tri-lobe industrial lobe pump of high capacity is simulated by using commercial CFD solver Ansys Fluent. A combination of user-defined-functions and meshing strategies is employed t...The performance of a newly designed tri-lobe industrial lobe pump of high capacity is simulated by using commercial CFD solver Ansys Fluent. A combination of user-defined-functions and meshing strategies is employed to capture the rotation of the lobes. The numerical model is validated by comparing the simulated results with the literature values. The processes of suction, displacement, compression and exhaust are accurately captured in the transient simulation. The fluid pressure value remains in the range of inlet pressure value till the processes of suction and displacement are over. The instantaneous process of compression is accurately captured in the simulation. The movement of a particular working chamber is traced along the gradual degree of lobe’s rotation. At five different degrees of lobe’s rotation, pressure contour plots are reported which clearly shows the pressure values inside the working chamber. Each pressure value inside the working chamber conforms to the particular process in which the working chamber is operating. Finally, the power requirement at the shaft of rotation is estimated from the simulated values. The estimated value of power requirement is 3.61 BHP FHP whereas the same calculated theoretically is 3 BHP FHP. The discrepancy is attributed to the assumption of symmetry of blower along the thickness.展开更多
Partial epilepsies, originating in a specific brain region, affect about 60% of adults with epilepsy. Temporal lobe epilepsy (TLE) is the most prevalent subtype within this category, often necessitating surgical inter...Partial epilepsies, originating in a specific brain region, affect about 60% of adults with epilepsy. Temporal lobe epilepsy (TLE) is the most prevalent subtype within this category, often necessitating surgical intervention due to its refractoriness to antiepileptic drugs (AEDs). Hippocampal sclerosis, a common underlying pathology, often exacerbates the severity by introducing cognitive and emotional challenges. This review delves deeper into the cognitive profile of TLE, along with the risk factors for cognitive disorders, depression, and anxiety in this population.展开更多
The flow field and aerodynamic performances for the scarfed lobed forced mixer are studied based on a computational fluid dynamics（CFD） technique. A series of computations are conducted to obtain the effects of the ...The flow field and aerodynamic performances for the scarfed lobed forced mixer are studied based on a computational fluid dynamics（CFD） technique. A series of computations are conducted to obtain the effects of the bypass ratio and the scarf angle on the mixing performance for the scarfed lobed mixer. Results show that the scarfed lobed mixer is reduced in the system weight. Meanwhile, aerodynamic performances are slightly improved compared with the normal lobed mixer. Two reasons for causing the mixing enhancement between the core and the bypass flow are as follows： （1） The stream-wise vortices shed from the training edge of the half/full scarfed lobed mixer earlier is enhanced by about 25%. （2） The mixing augmentation is also associated with the increase of the interface length caused by scarfing. The thermal mixing efficiency is enhanced with the increase of the bypass ratio and the scarfing angle. The scarfed lobed mixer design has no negative effects on the pressure loss. The total pressure recovery coefficient reaches above 0. 935 in various bypass ratios and scarfed angles. As the bypass ratio increases, the total pressure recovery coefficient also increases for the scarfed lobed mixer.展开更多
[Objective] We aimed to investigate the preventive and therapeutical effect of compound of traditional Chinese drugs （Japanese raisintree fruit, lobed kudzuvine flower bud and lightyel ow sophora root） on acute alc...[Objective] We aimed to investigate the preventive and therapeutical effect of compound of traditional Chinese drugs （Japanese raisintree fruit, lobed kudzuvine flower bud and lightyel ow sophora root） on acute alcohol intoxication in mice. [Method] Acute alcohol intoxication was induced by administering alcohol to mice. Three different doses （low, middle and high） of compound of traditional Chinese drugs were administered to mice before and after administering alcohol respectively to investigate the preventive and therapeutical effect of drugs on acute alcohol intox-ication through doing statistical analysis about drunk mice and their sleeping time. The concentration of malondialdehyde （MDA）, reduced glutathione （GSH） and triglyc-erides （TG） in liver was also determined to investigate the protective effect of drugs on liver. [Result] The efficacy of compound of traditional Chinese drugs on acute al-cohol intoxication was dose-dependent. High-dose administration decreased the number of drunk mice significantly compared with control group; middle- and high-dose administration reduced the sleeping time of drunk mice and the concentration of MDA and TG in liver tissue; three doses al increased the concentration of GSH. [Conclusion] The compound of Japanese raisintree fruit, lobed kudzuvine flower bud and lightyel ow sophora root had preventive and therapeutical effect on hangover, and it also had certain preventive and therapeutical effect on liver damage caused by alcohol.展开更多
Temporal lobe epilepsy is the most common form of focal epilepsy in adults,accounting for one third of all diagnosed epileptic patients,with seizures originating from or involving mesial temporal structures such as th...Temporal lobe epilepsy is the most common form of focal epilepsy in adults,accounting for one third of all diagnosed epileptic patients,with seizures originating from or involving mesial temporal structures such as the hippocampus,and many of these patients being refractory to treatment with anti-epileptic drugs.Temporal lobe epilepsy is the most common childhood neurological disorder and,compared with adults,the symptoms are greatly affected by age and brain development.Diagnosis of temporal lobe epilepsy relies on clinical examination,patient history,electroencephalographic recordings,and brain imaging.Misdiagnosis or delay in diagnosis is common.A molecular biomarker that could distinguish epilepsy from healthy subjects and other neurological conditions would allow for an earlier and more accurate diagnosis and appropriate treatment to be initiated.Among possible biomarkers of pathological changes as well as potential therapeutic targets in the epileptic brain are micro RNAs.Most of the recent studies had performed micro RNA profiling in body fluids such as blood plasma and blood serum and brain tissues such as temporal cortex tissue and hippocampal tissue.A large number of micro RNAs were dysregulated when compared to healthy controls and with some overlap between individual studies that could serve as potential biomarkers.For example,in adults with temporal lobe epilepsy,possible biomarkers are miR-199a-3p in blood plasma and miR-142-5p in blood plasma and blood serum.In adults with mesial temporal lobe epilepsy,possible biomarkers are miR-153 in blood plasma and miR-145-3p in blood serum.However,in many of the studies involving patients who receive one or several anti-epileptic drugs,the influence of these on micro RNA expression in body fluids and brain tissues is largely unknown.Further studies are warranted with children with temporal lobe epilepsy and consideration should be given to utilizing mouse or rat and non-human primate models of temporal lobe epilepsy.The animal models could be used to confirm micro RNA findings in human patients and to test the effects of targeting specific micro RNAs on disease progression and behavior.展开更多
AIM To analyze the outcomes of living-donor liver transplantation(LDLT) using left-lobe(LL) or right-lobe(RL) small-for-size(SFS) grafts.METHODS Prospectively collected data of adult patients who underwent LDLT at our...AIM To analyze the outcomes of living-donor liver transplantation(LDLT) using left-lobe(LL) or right-lobe(RL) small-for-size(SFS) grafts.METHODS Prospectively collected data of adult patients who underwent LDLT at our hospital in the period from January 2003 to December 2013 were reviewed. The patients were divided into the RL-LDLT group and the LL-LDLT group. The two groups were compared in terms of short-and long-term outcomes, including incidence of postoperative complication, graft function, graft survival, and patient survival. A SFS graft was defined as a graft with a ratio of graft weight(GW) to recipient standard liver volume(RSLV)(GW/RSLV) of < 50%. The Urata formula was used to estimate RSLV.RESULTS Totally 218 patients were included for analysis, with 199 patients in the RL-LDLT group and 19 patients in the LL-LDLT group. The two groups were similar in terms of age(median, 53 years in the RL-LDLT group and 52 years in the LL-LDLT group, P = 0.997) but had significantly different ratios of men to women(165:34 in the RL-LDLT group and 8:11 in the LL-LDLT group, P < 0.0001). The two groups were also significantly different in GW(P < 0.0001), GW/RSLV(P < 0.0001), and graft cold ischemic time(P = 0.007). When it comes to postoperative complication, the groups were comparable(P = 0.105). Five patients died in hospital,4(2%) in the RL-LDLT group and 1(5.3%) in the LLLDLT group(P = 0.918). There were 38 graft losses, 33(16.6%) in the RL-LDLT group and 5(26.3%) in the LL-LDLT group(P = 0.452). The 5-year graft survival rate was significantly better in the RL-LDLT group(95.2% vs 89.5%, P = 0.049). The two groups had similar 5-year patient survival rates(RL-LDLT: 86.8%, LL-LDLT: 89.5%, P = 0.476).CONCLUSION The use of SFS graft in LDLT requires careful tailormade surgical planning and meticulous operation. LLLDLT can be a good alternative to RL-LDLT with similar recipient outcomes but a lower donor risk. Further research into different patient conditions is needed in order to validate the use of LL graft.展开更多
Background:Current reports on robotic hepatic caudate lobectomy are limited to Spiegel lobectomy.This study aimed to compare the safety and feasibility of robotic isolated partial and complete hepatic caudate lobectom...Background:Current reports on robotic hepatic caudate lobectomy are limited to Spiegel lobectomy.This study aimed to compare the safety and feasibility of robotic isolated partial and complete hepatic caudate lobectomy.Methods:Clinical data of 32 patients who underwent robotic resection of the hepatic caudate lobe in our department from May 2016 to January 2020 were retrospectively analyzed.The patients were divided into three groups according to the lobectomy location:left dorsal segment lobectomy(Spiegel lobectomy),right dorsal segment lobectomy(caudate process or paracaval portion lobectomy),and complete caudate lobectomy.General information and perioperative results of the three groups were compared and analyzed.Results:Among the 32 patients,none had conversion to laparotomy,three received intraoperative blood transfusion(9.38%),and none had complications of Clavien-Dindo gradeⅢor higher or died in the perioperative period.Among them,17 patients(53.13%)underwent Spiegel lobectomy,7(21.88%)underwent caudate process or paracaval portion lobectomy,and 8(25.00%)underwent complete caudate lobectomy.The operative time and blood loss in the left dorsal segment lobectomy group were significantly better than those in the right dorsal segment lobectomy and complete caudate lobectomy groups(operative time:P=0.010 and P=0.005;blood loss:P=0.005 and P=0.017,respectively).The postoperative hospital stay in the left dorsal segment lobectomy group was significantly shorter than that in the complete caudate lobectomy group(P=0.003);however,there was no difference in the postoperative hospital stay between the left dorsal segment lobectomy group and right dorsal segment lobectomy group(P=0.240).Conclusions:Robotic isolated partial and complete caudate lobectomy is safe and feasible.Spiegel lobectomy is relatively straightforward and suitable for beginners.展开更多
BACKGROUND Caudate lobe hemangioma of the liver is relatively rare.Due to the unique anatomical location of the caudate lobe,the caudate lobectomy accounts for only 0.5%to 4%of hepatic resection,which is difficult to ...BACKGROUND Caudate lobe hemangioma of the liver is relatively rare.Due to the unique anatomical location of the caudate lobe,the caudate lobectomy accounts for only 0.5%to 4%of hepatic resection,which is difficult to operate and takes a long time,and even has many postoperative complications.CASE SUMMARY A 34-year-old female presented with a 1 year history of intermittent pain in the right side of the waist without obvious inducement.All laboratory blood tests were within normal limits.Indocyanine green 15 min retention was rated 2.9%,and Child-Pugh was rated A.Computed tomography and magnetic resonance imaging diagnosed giant hemangioma of the caudate lobe with hemangioma of left lobe of liver.After discussion,surgical treatment was performed,which lasted 410 min,with intraoperative bleeding of about 600 mL and postoperative pathological findings of cavernous hemangioma.There were no obvious postoperative complications,and the patient was discharged 10 d after surgery.CONCLUSION Caudate lobectomy is difficult due to its special anatomical location.Under the condition of fully exposing the anatomy of the first porta hepatis,the second porta hepatis,the third porta hepatis,the fourth porta hepatis and middle hepatic vein and combining with the Pringle maneuver,caudate lobectomy can be performed in a precise and safe process.展开更多
在机床各种形式的振动中,再生颤振具有最小的稳定极限切削宽度,换言之,机床抵抗再生颤振的能力最差。品质系数(Coefficient of Merit,COM)是切削力和切削表面法向相对位移之间的交叉频响函数最小负实部的函数,其大小直接反映机床抵抗再...在机床各种形式的振动中,再生颤振具有最小的稳定极限切削宽度,换言之,机床抵抗再生颤振的能力最差。品质系数(Coefficient of Merit,COM)是切削力和切削表面法向相对位移之间的交叉频响函数最小负实部的函数,其大小直接反映机床抵抗再生颤振的能力。此外,在机床的连续使用过程中,品质系数COM会逐渐减小,进而影响机床再生颤振抗振能力。基于相对激振方法和四自由度立铣加工过程动力学模型,重点分析了机床相对动柔度劣化过程中品质系数COM的变化趋势,以及对加工过程稳定性Lobe图的影响。研究表明:随着机床相对动柔度的劣化,轴向极限切深ap逐渐减小,并有加速递减的趋势,这和机床品质系数的劣化趋势一致。因此,考虑机床相对动柔度对稳定性Lobe图的影响,才能确定更合适的工艺参数,保证切削过程的稳定性,提高加工效率。展开更多
基金supported by grants from the National Key R&D Program of China(2020YFA0803900)the National Natural Science Foundation of China(82173796 and U21A20418)+1 种基金the Natural Science Foundation of Zhejiang Province(LD22H310003)the Key R&D Plan of Zhejiang Province(2021C03116).
文摘Approximately 30%-40% of epilepsy patients do not respond well to adequate anti-seizure medications(ASMs),a condition known as pharmacoresistant epilepsy.The management of pharmacoresistant epilepsy remains an intractable issue in the clinic.Its early prediction is important for prevention and diagnosis.However,it still lacks effective predictors and approaches.Here,a classical model of pharmacoresistant temporal lobe epilepsy(TLE)was established to screen pharmacoresistant and pharmaco-responsive individuals by applying phenytoin to amygdaloid-kindled rats.Ictal electroencephalograms(EEGs)recorded before phenytoin treatment were analyzed.Based on ictal EEGs from pharmacoresistant and pharmaco-responsive rats,a convolutional neural network predictive model was constructed to predict pharmacoresistance,and achieved 78% prediction accuracy.We further found the ictal EEGs from pharmacoresistant rats have a lower gamma-band power,which was verified in seizure EEGs from pharmacoresistant TLE patients.Prospectively,therapies targeting the subiculum in those predicted as“pharmacoresistant”individual rats significantly reduced the subsequent occurrence of pharmacoresistance.These results demonstrate a new methodology to predict whether TLE individuals become resistant to ASMs in a classic pharmacoresistant TLE model.This may be of translational importance for the precise management of pharmacoresistant TLE.
文摘Thinning of antenna arrays has been a popular topic for the last several decades.With increasing computational power,this optimization task acquired a new hue.This paper suggests a genetic algorithm as an instrument for antenna array thinning.The algorithm with a deliberately chosen fitness function allows synthesizing thinned linear antenna arrays with low peak sidelobe level(SLL)while maintaining the half-power beamwidth(HPBW)of a full linear antenna array.Based on results from existing papers in the field and known approaches to antenna array thinning,a classification of thinning types is introduced.The optimal thinning type for a linear thinned antenna array is determined on the basis of a maximum attainable SLL.The effect of thinning coefficient on main directional pattern characteristics,such as peak SLL and HPBW,is discussed for a number of amplitude distributions.
基金supported by a grant from the Climbing Project for Medical Talent of Zhongnan Hospital,Wuhan University(PDJH202215).
文摘To the Editor:Theoretically,autologous liver transplantation is posited as a treatment for patients experiencing traumatic liver rupture.How-ever,the procedural complexity and its infrequent application by the medical community have resulted in a lack of documented suc-cesses.This report presented the efficacious intervention in a pa-tient presenting with polytraumatic injuries involving the thoracic and abdominal regions,namely right-sided hemothorax,contusion and hematoma of the right lung,splenic rupture,lateral damage to the common bile duct,disruption of the left portal vein branch and left hepatic duct,incisions in the hepatic segments IV,V,VI,VII,and VIII,laceration of the right adrenal gland,rupture of the right hepatic venous trunk and retro-hepatic inferior vena cava(RHIVC),and pancreatic hematoma.
基金supported by the National Natural Science Foundation of China(32130089)the Norwegian Research Council(324379)。
文摘In insects,the number and specificity of antennal lobe glomeruli often reflect the number and diversity of expressed chemosensory genes,which are linked to its ecological niche and specific olfactory needs.The oriental armyworm,Mythimna separata,is an important and common lepidopteran pest of cereal crops.Given its reliance on the olfactory system for crucial behaviors,understanding the evolutionary potential of this system requires a thorough characterization of the anatomical structure of the primary olfactory center.Here,we systematically identified all antennal lobe glomeruli of M.separata based on synaptic antibody immunostaining and mass staining of the olfactory sensory neurons.A total of 69 glomeruli were identified in females and 65 in males,and an intuitive nomenclature based on glomerular positions was applied.Our findings uncovered some sex-specific glomeruli in this species.There were ten female-specific glomeruli and three male-specific glomeruli,except for the macroglomerular complex(MGC)units,with a notable observation that the female labial pit organ glomerulus was larger than its male counterpart.Additionally,we identified four antennal-lobe tracts(ALTs)and retrograde labeling from the calyx revealed that all glomeruli were innervated by the medial ALT projection neurons.The comparison of the olfactory system structures between M.separata and sympatric moths supports their evolutionary convergence in noctuid moths.These results collectively lay the foundation for future studies on olfactory processing in M.separata.
基金supported by the National Major Scientific and Technological Special Project for Significant New Drugs Development(2019zx09301102)the Project of Liaoning Provincial Department of Education(LJKZ0826)the Open Project of National and Local Joint Engineering Research Center for Drug Research and Development of Neurodegenerative Diseases(2022GCYJZX-YB02).
文摘Neuroinflammation mediated by microglia and oxidative stress play pivotal roles in the development of chronic temporal lobe epilepsy(TLE).We postulated that kainic acid(KA)-Induced status epilepticus triggers microglia-dependent inflammation,leading to neuronal damage,a lowered seizure threshold,and the emergence of spontaneous recurrent seizures(SRS).Extensive evidence from our laboratory suggests that dextromethorphan(DM),even in ultra-low doses,has anti-inflammatory and neuroprotective effects in many animal models of neurodegenerative disease.Our results showed that administration of DM(10 ng/kg per day;subcutaneously via osmotic minipump for 4 weeks)significantly mitigated the residual effects of KA,including the frequency of SRS and seizure susceptibility.In addition,DM-treated rats showed improved cognitive function and reduced hippocampal neuronal loss.We found suppressed microglial activation-mediated neuroinflammation and decreased expression of hippocampal gp91^(phox) and p47^(phox) proteins in KA-induced chronic TLE rats.Notably,even after discontinuation of DM treatment,ultra-low doses of DM continued to confer long-term anti-seizure and neuroprotective effects,which were attributed to the inhibition of microglial NADPH oxidase 2 as revealed by mechanistic studies.
基金supported by grants from the National Natural Science Foundation of China(U21A20418 and 82173796)the Natural Science Foundation of Zhejiang Province(LD22H310003)the Research Project of Zhejiang Chinese Medical University(2023JKZDZC04).
文摘Secondary epileptogenesis is characterized by increased epileptic susceptibility and a tendency to generate epileptiform activities outside the primary focus.It is one of the major resultants of pharmacoresistance and failure of surgical outcomes in epilepsy,but still lacks effective treatments.Here,we aimed to test the effects of low-frequency stimulation(LFS)at the subiculum for secondary epileptogenesis in a mouse model.Here,secondary epileptogenesis was simulated at regions both contralateral and ipsilateral to the primary focus by applying successive kindling stimuli.Mice kindled at the right CA3 showed higher seizure susceptibilities at both the contralateral CA3 and the ipsilateral entorhinal cortex and had accelerated kindling processes compared with naive mice.LFS at the ipsilateral subiculum during the primary kindling progress at the right CA3 effectively prevented secondary epileptogenesis at both the contralateral CA3 and the ipsilateral entorhinal cortex,characterized by decreased seizure susceptibilities and a retarded kindling process at those secondary foci.Only application along with the primary epileptogenesis was effective.Notably,the effects of LFS on secondary epileptogenesis were associated with its inhibitory effect at the secondary focus through interfering with the enhancement of synaptic connections between the primary and secondary foci.These results imply that LFS at the subiculum is an effective preventive strategy for extensive secondary epileptogenesis in temporal lobe epilepsy and present the subiculum as a target with potential translational importance.
基金supported by the National Natural Science Foundation of China,Nos.62027812(to HS),81771470(to HS),and 82101608(to YL)Tianjin Postgraduate Research and Innovation Project,No.2020YJSS122(to XD)。
文摘Temporal lobe epilepsy is a multifactorial neurological dysfunction syndrome that is refractory,resistant to antiepileptic drugs,and has a high recurrence rate.The pathogenesis of temporal lobe epilepsy is complex and is not fully understood.Intracellular calcium dynamics have been implicated in temporal lobe epilepsy.However,the effect of fluctuating calcium activity in CA1 pyramidal neurons on temporal lobe epilepsy is unknown,and no longitudinal studies have investigated calcium activity in pyramidal neurons in the hippocampal CA1 and primary motor cortex M1 of freely moving mice.In this study,we used a multichannel fiber photometry system to continuously record calcium signals in CA1 and M1 during the temporal lobe epilepsy process.We found that calcium signals varied according to the grade of temporal lobe epilepsy episodes.In particular,cortical spreading depression,which has recently been frequently used to represent the continuously and substantially increased calcium signals,was found to correspond to complex and severe behavioral characteristics of temporal lobe epilepsy ranging from gradeⅡto gradeⅤ.However,vigorous calcium oscillations and highly synchronized calcium signals in CA1 and M1 were strongly related to convulsive motor seizures.Chemogenetic inhibition of pyramidal neurons in CA1 significantly attenuated the amplitudes of the calcium signals corresponding to gradeⅠepisodes.In addition,the latency of cortical spreading depression was prolonged,and the above-mentioned abnormal calcium signals in CA1 and M1 were also significantly reduced.Intriguingly,it was possible to rescue the altered intracellular calcium dynamics.Via simultaneous analysis of calcium signals and epileptic behaviors,we found that the progression of temporal lobe epilepsy was alleviated when specific calcium signals were reduced,and that the end-point behaviors of temporal lobe epilepsy were improved.Our results indicate that the calcium dynamic between CA1 and M1 may reflect specific epileptic behaviors corresponding to different grades.Furthermore,the selective regulation of abnormal calcium signals in CA1 pyramidal neurons appears to effectively alleviate temporal lobe epilepsy,thereby providing a potential molecular mechanism for a new temporal lobe epilepsy diagnosis and treatment strategy.
基金Key Clinical Specialty Discipline Construction Program of Fujian,Fujian Health Medicine and Politics,No.[2022]884.
文摘BACKGROUND In laparoscopic proximal gastrectomy(LPG),the prolapse of the hepatic left lateral lobe near the lesser curvature and esophageal hiatus can obstruct the field of vision and operation.Therefore,it is necessary to retract or obstruct the hepatic left lateral lobe to ensure a clear field of vision.AIM To investigate the safety and clinical efficacy of the modified hepatic left lateral lobe inversion technique for LPG.METHODS A retrospective analysis was conducted on the clinical data of 13 consecutive patients with early-stage upper gastric adenocarcinoma or adenocarcinoma of the esophagogastric junction treated with LPG from January to December 2023 at the Department of Gastrointestinal Surgery,Second Affiliated Hospital of Fujian Medical University.The modified hepatic left lateral lobe inversion technique was used to expose the surgical field in all patients,and short-term outcomes were observed.RESULTS In all 13 patients,the modified hepatic left lateral lobe inversion technique was successful during surgery without the need for re-retraction or alteration of the liver traction method.There were no instances of esophageal hiatus occlusion,eliminating the need for forceps to assist in exposure.There was no occurrence of intraoperative hepatic hemorrhage,hepatic vein injury,or hepatic congestion.No postoperative digestive complications of Clavien-Dindo grade≥II occurred wi-thin 30 days after surgery,except for a single case of pulmonary infection.Some patients experienced increases in alanine aminotransferase and aspartate aminotransferase levels on the first day after surgery,which significantly decreased by the third day and returned to normal by the seventh day after surgery.CONCLUSION The modified hepatic left lateral lobe inversion technique has demonstrated satisfactory results,offering ad-vantages in terms of facilitating surgical procedures,reducing surgical trauma,and protecting the liver.
基金the Natural Science Foundation of the Fujian Province,No.2021J01876.
文摘BACKGROUND Gelastic seizure(GS)is a rare type of epilepsy that most commonly appears in patients with hypothalamic hamartoma.It is rarely associated with other types of brain damage.This particular type of epilepsy is relatively rare and has few links to other brain lesions.Temporal lobe malacia is mostly caused by cerebral infarction or cerebral hemorrhage,which can lead to seizures.We report a case of GS in a woman with temporal lobe malacia which was reported for the first time in the literature.CASE SUMMARY A 73-year-old female,diagnosed case of GS,presented with repetitive stereotyped laughter a month prior to presentation,happening multiple times daily and with each time lasting for 5-15s.Electroencephalogram displayed a focal seizure seen in the right temporal region.Magnetic resonance imaging head with contrast showed a right temporal lobe malacia.The patient was started on levetiracetam daily.The patient indicated that they had fully recovered and were not experiencing any recurrent or stereotyped laughter during their daily routines.These results remained consistent even after a one-year follow-up period.CONCLUSION GS can be caused by temporal lobe malacia,which is an uncommon but potentially grave condition.The outcome of this present case exhibited the importance of the temporal lobe in the genesis of GS.
文摘The performance of a newly designed tri-lobe industrial lobe pump of high capacity is simulated by using commercial CFD solver Ansys Fluent. A combination of user-defined-functions and meshing strategies is employed to capture the rotation of the lobes. The numerical model is validated by comparing the simulated results with the literature values. The processes of suction, displacement, compression and exhaust are accurately captured in the transient simulation. The fluid pressure value remains in the range of inlet pressure value till the processes of suction and displacement are over. The instantaneous process of compression is accurately captured in the simulation. The movement of a particular working chamber is traced along the gradual degree of lobe’s rotation. At five different degrees of lobe’s rotation, pressure contour plots are reported which clearly shows the pressure values inside the working chamber. Each pressure value inside the working chamber conforms to the particular process in which the working chamber is operating. Finally, the power requirement at the shaft of rotation is estimated from the simulated values. The estimated value of power requirement is 3.61 BHP FHP whereas the same calculated theoretically is 3 BHP FHP. The discrepancy is attributed to the assumption of symmetry of blower along the thickness.
文摘Partial epilepsies, originating in a specific brain region, affect about 60% of adults with epilepsy. Temporal lobe epilepsy (TLE) is the most prevalent subtype within this category, often necessitating surgical intervention due to its refractoriness to antiepileptic drugs (AEDs). Hippocampal sclerosis, a common underlying pathology, often exacerbates the severity by introducing cognitive and emotional challenges. This review delves deeper into the cognitive profile of TLE, along with the risk factors for cognitive disorders, depression, and anxiety in this population.
基金Supported by the Civil Aviation Research Foundation of Nanjing University of Aeronautics and Astronautics~~
文摘The flow field and aerodynamic performances for the scarfed lobed forced mixer are studied based on a computational fluid dynamics（CFD） technique. A series of computations are conducted to obtain the effects of the bypass ratio and the scarf angle on the mixing performance for the scarfed lobed mixer. Results show that the scarfed lobed mixer is reduced in the system weight. Meanwhile, aerodynamic performances are slightly improved compared with the normal lobed mixer. Two reasons for causing the mixing enhancement between the core and the bypass flow are as follows： （1） The stream-wise vortices shed from the training edge of the half/full scarfed lobed mixer earlier is enhanced by about 25%. （2） The mixing augmentation is also associated with the increase of the interface length caused by scarfing. The thermal mixing efficiency is enhanced with the increase of the bypass ratio and the scarfing angle. The scarfed lobed mixer design has no negative effects on the pressure loss. The total pressure recovery coefficient reaches above 0. 935 in various bypass ratios and scarfed angles. As the bypass ratio increases, the total pressure recovery coefficient also increases for the scarfed lobed mixer.
基金Supported by National Natural Science Foundation of China(31100987)Project of Shandong University of Technology(4040-306018)Young Teacher Development Plan of Shandong University of Technology~~
文摘[Objective] We aimed to investigate the preventive and therapeutical effect of compound of traditional Chinese drugs （Japanese raisintree fruit, lobed kudzuvine flower bud and lightyel ow sophora root） on acute alcohol intoxication in mice. [Method] Acute alcohol intoxication was induced by administering alcohol to mice. Three different doses （low, middle and high） of compound of traditional Chinese drugs were administered to mice before and after administering alcohol respectively to investigate the preventive and therapeutical effect of drugs on acute alcohol intox-ication through doing statistical analysis about drunk mice and their sleeping time. The concentration of malondialdehyde （MDA）, reduced glutathione （GSH） and triglyc-erides （TG） in liver was also determined to investigate the protective effect of drugs on liver. [Result] The efficacy of compound of traditional Chinese drugs on acute al-cohol intoxication was dose-dependent. High-dose administration decreased the number of drunk mice significantly compared with control group; middle- and high-dose administration reduced the sleeping time of drunk mice and the concentration of MDA and TG in liver tissue; three doses al increased the concentration of GSH. [Conclusion] The compound of Japanese raisintree fruit, lobed kudzuvine flower bud and lightyel ow sophora root had preventive and therapeutical effect on hangover, and it also had certain preventive and therapeutical effect on liver damage caused by alcohol.
文摘Temporal lobe epilepsy is the most common form of focal epilepsy in adults,accounting for one third of all diagnosed epileptic patients,with seizures originating from or involving mesial temporal structures such as the hippocampus,and many of these patients being refractory to treatment with anti-epileptic drugs.Temporal lobe epilepsy is the most common childhood neurological disorder and,compared with adults,the symptoms are greatly affected by age and brain development.Diagnosis of temporal lobe epilepsy relies on clinical examination,patient history,electroencephalographic recordings,and brain imaging.Misdiagnosis or delay in diagnosis is common.A molecular biomarker that could distinguish epilepsy from healthy subjects and other neurological conditions would allow for an earlier and more accurate diagnosis and appropriate treatment to be initiated.Among possible biomarkers of pathological changes as well as potential therapeutic targets in the epileptic brain are micro RNAs.Most of the recent studies had performed micro RNA profiling in body fluids such as blood plasma and blood serum and brain tissues such as temporal cortex tissue and hippocampal tissue.A large number of micro RNAs were dysregulated when compared to healthy controls and with some overlap between individual studies that could serve as potential biomarkers.For example,in adults with temporal lobe epilepsy,possible biomarkers are miR-199a-3p in blood plasma and miR-142-5p in blood plasma and blood serum.In adults with mesial temporal lobe epilepsy,possible biomarkers are miR-153 in blood plasma and miR-145-3p in blood serum.However,in many of the studies involving patients who receive one or several anti-epileptic drugs,the influence of these on micro RNA expression in body fluids and brain tissues is largely unknown.Further studies are warranted with children with temporal lobe epilepsy and consideration should be given to utilizing mouse or rat and non-human primate models of temporal lobe epilepsy.The animal models could be used to confirm micro RNA findings in human patients and to test the effects of targeting specific micro RNAs on disease progression and behavior.
文摘AIM To analyze the outcomes of living-donor liver transplantation(LDLT) using left-lobe(LL) or right-lobe(RL) small-for-size(SFS) grafts.METHODS Prospectively collected data of adult patients who underwent LDLT at our hospital in the period from January 2003 to December 2013 were reviewed. The patients were divided into the RL-LDLT group and the LL-LDLT group. The two groups were compared in terms of short-and long-term outcomes, including incidence of postoperative complication, graft function, graft survival, and patient survival. A SFS graft was defined as a graft with a ratio of graft weight(GW) to recipient standard liver volume(RSLV)(GW/RSLV) of < 50%. The Urata formula was used to estimate RSLV.RESULTS Totally 218 patients were included for analysis, with 199 patients in the RL-LDLT group and 19 patients in the LL-LDLT group. The two groups were similar in terms of age(median, 53 years in the RL-LDLT group and 52 years in the LL-LDLT group, P = 0.997) but had significantly different ratios of men to women(165:34 in the RL-LDLT group and 8:11 in the LL-LDLT group, P < 0.0001). The two groups were also significantly different in GW(P < 0.0001), GW/RSLV(P < 0.0001), and graft cold ischemic time(P = 0.007). When it comes to postoperative complication, the groups were comparable(P = 0.105). Five patients died in hospital,4(2%) in the RL-LDLT group and 1(5.3%) in the LLLDLT group(P = 0.918). There were 38 graft losses, 33(16.6%) in the RL-LDLT group and 5(26.3%) in the LL-LDLT group(P = 0.452). The 5-year graft survival rate was significantly better in the RL-LDLT group(95.2% vs 89.5%, P = 0.049). The two groups had similar 5-year patient survival rates(RL-LDLT: 86.8%, LL-LDLT: 89.5%, P = 0.476).CONCLUSION The use of SFS graft in LDLT requires careful tailormade surgical planning and meticulous operation. LLLDLT can be a good alternative to RL-LDLT with similar recipient outcomes but a lower donor risk. Further research into different patient conditions is needed in order to validate the use of LL graft.
文摘Background:Current reports on robotic hepatic caudate lobectomy are limited to Spiegel lobectomy.This study aimed to compare the safety and feasibility of robotic isolated partial and complete hepatic caudate lobectomy.Methods:Clinical data of 32 patients who underwent robotic resection of the hepatic caudate lobe in our department from May 2016 to January 2020 were retrospectively analyzed.The patients were divided into three groups according to the lobectomy location:left dorsal segment lobectomy(Spiegel lobectomy),right dorsal segment lobectomy(caudate process or paracaval portion lobectomy),and complete caudate lobectomy.General information and perioperative results of the three groups were compared and analyzed.Results:Among the 32 patients,none had conversion to laparotomy,three received intraoperative blood transfusion(9.38%),and none had complications of Clavien-Dindo gradeⅢor higher or died in the perioperative period.Among them,17 patients(53.13%)underwent Spiegel lobectomy,7(21.88%)underwent caudate process or paracaval portion lobectomy,and 8(25.00%)underwent complete caudate lobectomy.The operative time and blood loss in the left dorsal segment lobectomy group were significantly better than those in the right dorsal segment lobectomy and complete caudate lobectomy groups(operative time:P=0.010 and P=0.005;blood loss:P=0.005 and P=0.017,respectively).The postoperative hospital stay in the left dorsal segment lobectomy group was significantly shorter than that in the complete caudate lobectomy group(P=0.003);however,there was no difference in the postoperative hospital stay between the left dorsal segment lobectomy group and right dorsal segment lobectomy group(P=0.240).Conclusions:Robotic isolated partial and complete caudate lobectomy is safe and feasible.Spiegel lobectomy is relatively straightforward and suitable for beginners.
基金Supported by National Natural Science Foundation of China,No.81660398Hospital Key Program of National Scientific Research Cultivation Plan,No.19SYPYA-12.
文摘BACKGROUND Caudate lobe hemangioma of the liver is relatively rare.Due to the unique anatomical location of the caudate lobe,the caudate lobectomy accounts for only 0.5%to 4%of hepatic resection,which is difficult to operate and takes a long time,and even has many postoperative complications.CASE SUMMARY A 34-year-old female presented with a 1 year history of intermittent pain in the right side of the waist without obvious inducement.All laboratory blood tests were within normal limits.Indocyanine green 15 min retention was rated 2.9%,and Child-Pugh was rated A.Computed tomography and magnetic resonance imaging diagnosed giant hemangioma of the caudate lobe with hemangioma of left lobe of liver.After discussion,surgical treatment was performed,which lasted 410 min,with intraoperative bleeding of about 600 mL and postoperative pathological findings of cavernous hemangioma.There were no obvious postoperative complications,and the patient was discharged 10 d after surgery.CONCLUSION Caudate lobectomy is difficult due to its special anatomical location.Under the condition of fully exposing the anatomy of the first porta hepatis,the second porta hepatis,the third porta hepatis,the fourth porta hepatis and middle hepatic vein and combining with the Pringle maneuver,caudate lobectomy can be performed in a precise and safe process.
文摘在机床各种形式的振动中,再生颤振具有最小的稳定极限切削宽度,换言之,机床抵抗再生颤振的能力最差。品质系数(Coefficient of Merit,COM)是切削力和切削表面法向相对位移之间的交叉频响函数最小负实部的函数,其大小直接反映机床抵抗再生颤振的能力。此外,在机床的连续使用过程中,品质系数COM会逐渐减小,进而影响机床再生颤振抗振能力。基于相对激振方法和四自由度立铣加工过程动力学模型,重点分析了机床相对动柔度劣化过程中品质系数COM的变化趋势,以及对加工过程稳定性Lobe图的影响。研究表明:随着机床相对动柔度的劣化,轴向极限切深ap逐渐减小,并有加速递减的趋势,这和机床品质系数的劣化趋势一致。因此,考虑机床相对动柔度对稳定性Lobe图的影响,才能确定更合适的工艺参数,保证切削过程的稳定性,提高加工效率。
