BACKGROUND A 56-year-old female presented with acute abdominal pain due to a ruptured pseudoaneurysm associated with median arcuate ligament syndrome(MALS),a rare condition caused by the compression of the celiac arte...BACKGROUND A 56-year-old female presented with acute abdominal pain due to a ruptured pseudoaneurysm associated with median arcuate ligament syndrome(MALS),a rare condition caused by the compression of the celiac artery by the median arcuate ligament(MAL),potentially leading to ischemia,aneurysm formation,and rupture.CASE SUMMARY Computed tomography revealed a retroperitoneal hematoma,celiac artery stenosis,and two aneurysms in the inferior pancreaticoduodenal artery.Hemo-stasis was achieved using transcatheter arterial embolization.However,15 days after embolization,the patient developed duodenal stenosis,manifesting as gastric distension and nausea without abdominal pain.Endoscopy revealed mucosal edema and luminal narrowing of the duodenum.Conservative treatment was ineffective,and the patient underwent MAL transection and gastrojejun-ostomy.She recovered uneventfully,and follow-up at 4 months showed complete resolution of duodenal stenosis and no recurrence.CONCLUSION This case highlights the importance of the early diagnosis and multidisciplinary management of MALS.展开更多
AIM： To explore the mechanism for interactions of leptin with ghrelin and orexin in the arcuate nucleus （ARC） activating neuropeptide Y （NPY） neurons during physiological regulation of feeding, METHODS： Single n...AIM： To explore the mechanism for interactions of leptin with ghrelin and orexin in the arcuate nucleus （ARC） activating neuropeptide Y （NPY） neurons during physiological regulation of feeding, METHODS： Single neurons from ARC of adult rats with matured feeding function were isolated. [Ca2＋]i was measured to monitore their activities. The time course of leptin effects on ghrelin-induced versus orexin-induced [Ca2＋]i increases in NPY neurons was studied. RESULTS： Administration of ghrelin or orexin-A at 101~ mol/L increased cytosolic Ca2~ concentration （[Ca2＋]~） in NPY neurons isolated from the ARC of adult rats. Upon administration of leptin at 10^-14-10^-12 mol/L, ghrelin-induced [Ca2＋]i increases were initially （〈 10 min） inhibited but later restored, exhibiting a transient pattern of inhibition. In contrast, orexin-induced [Ca2＋]i increases were inhibited by leptin in a long- lasting manner. Furthermore, a prior administration of leptin inhibited orexin action but not ghrelin action to increase ICa 2＋li, CONCLUSION： Leptin counteracted ghrelin effects transiently and orexin effects long-lastingly in NPY neurons. The transient property with which leptin counteracts ghrelin action in NPY neurons may allow the fasting-associated increase in ghrelin levels to activate NPY neurons in the presence of physiological leptin and to stimulate feeding.展开更多
Purpose: The purpose of this study was to compare the deterministic and probabilistic tracking methods of diffusion tensor white matter fiber tractography in patients with brain tumors. Materials and Methods: We ident...Purpose: The purpose of this study was to compare the deterministic and probabilistic tracking methods of diffusion tensor white matter fiber tractography in patients with brain tumors. Materials and Methods: We identified 29 patients with left brain tumors ciculus was reconstructed using a deterministic Fiber Assignment by Continuous Tracking (FACT) algorithm and a probabilistic method based on an extended Monte Carlo Random Walk algorithm. Tracking was controlled using two ROIs corresponding to Broca’s and Wernicke’s areas. Tracts in tumoraffected hemispheres were examined for extension between Broca’s and Wernicke’s areas, anterior-posterior length and volume, and compared with the normal contralateral tracts. Results: Probabilistic tracts displayed more complete anterior extension to Broca’s area than did FACT tracts on the tumor-affected and normal sides (p rs.展开更多
In patients undergoing pancreaticoduodenectomy(PD),unrecognized hemodynamically significant celiac axis(CA) stenosis impairs hepatic arterial flow by suppressing the collateral pathways supplying arterial flow from th...In patients undergoing pancreaticoduodenectomy(PD),unrecognized hemodynamically significant celiac axis(CA) stenosis impairs hepatic arterial flow by suppressing the collateral pathways supplying arterial flow from the superior mesenteric artery and leads to serious hepatobiliary complications due to liver and biliary ischemia, with a high rate of mortality. CA stenosis is usually due to an extrinsic compression by a previously asymptomatic median arcuate ligament(MAL). MAL is diagnosed by computerized tomography in about 10% of the candidates for PD, but only half are found to be hemodynamically significant during the gastroduodenal artery clamping test with Doppler assessment, which is mandatory before any resection. MAL release is usually efficient to restore an adequate liver blood inflow and prevent ischemic complications. In cases of failure in MAL release, postponed PD with secondary stenting of the CA and reoperation for PD should be considered as an alternative to immediate hepatic artery re-construction, which involves the risk of postoperative thrombosis of the arterial reconstruction. We recently used this two-stage strategy in a patient undergoing surgery for pancreatic adenocarcinoma.展开更多
AIM:To evaluate corneal astigmatic outcomes of femtosecond laser-assisted arcuate keratotomies(FAKs)combined with femtosecond-laser assisted cataract surgery(FLACS)over 12mo follow-up.METHODS:Totally 145 patients with...AIM:To evaluate corneal astigmatic outcomes of femtosecond laser-assisted arcuate keratotomies(FAKs)combined with femtosecond-laser assisted cataract surgery(FLACS)over 12mo follow-up.METHODS:Totally 145 patients with bilateral cataracts and no ocular co-morbidities were recruited to a singlecentre,single-masked,prospective randomized controlled trial(RCT)comparing two monofocal hydrophobic acrylic intraocular lenses.Eyes with corneal astigmatism(CA)of>0.8 dioptres(D)received unpaired,unopened,surface penetrating FAKs at the time of FLACS.Visual acuity,subjective refraction and Scheimpflug tomography were recorded at 1,6,and 12mo.Alpins vectoral analyses were performed.RESULTS:Fifty-one patients(61 eyes),mean age 68.2±9.6y[standard deviation(SD)],received FAKs.Sixty eyes were available for analysis,except at 12mo when 59 attended.There were no complications due to FAKs.Mean pre-operative CA was 1.13±0.20 D.There was a reduction of astigmatism at all post-operative visits(residual CA 1mo:0.85±0.42 D,P=0.0001;6mo:0.86±0.35 D,P=0001;and 12mo:0.90±0.39,P=0.0001).Alpins indices remained stable over 12mo.Overall,the cohort was under-corrected at all time points.At 12mo,61%of eyes were within±15 degrees of pre-operative astigmatic meridian.CONCLUSION:Unpaired unopened penetrating FAKs combined with on-axis phacoemulsification are safe but minimally effective.CA is largely under-corrected in this cohort using an existing unmodified nomogram.The effect of arcuate keratotomies on CA remained stable over 12mo.展开更多
The arcuate fasciculus is a critical component of the neural substrate of human language function.Surgical resection of glioma adjacent to the arcuate fasciculus likely damages this region.In this study,we evaluated t...The arcuate fasciculus is a critical component of the neural substrate of human language function.Surgical resection of glioma adjacent to the arcuate fasciculus likely damages this region.In this study,we evaluated the outcome of surgical resection of glioma adjacent to the arcuate fasciculus under the guidance of magnetic resonance imaging and diffusion tensor imaging,and we aimed to identify the risk factors for postoperative linguistic deficit.In total,54 patients with primary glioma adjacent to the arcuate fasciculus were included in this observational study.These patients comprised 38 men and 16 women(aged 43±11 years).All patients underwent surgical resenction of glioma under the guidance of magnetic resonance imaging and diffusion tensor imaging.Intraoperative images were updated when necessary for further resection.The gross total resection rate of the 54 patients increased from 38.9%to 70.4%by intraoperative magnetic resonance imaging.Preoperative language function and glioma-to-arcuate fasciculus distance were associated with poor language outcome.Multivariable logistic regression analyses showed that glioma-to-arcuate fasciculus distance was the major independent risk factor for poor outcome.The cutoff point of glioma-to-arcuate fasciculus distance for poor outcome was 3.2 mm.These findings suggest that intraoperative magnetic resonance imaging combined with diffusion tensor imaging of the arcuate fasciculus can help optimize tumor resection and result in the least damage to the arcuate fasciculus.Notably,glioma-to-arcuate fasciculus distance is a key independent risk factor for poor postoperative language outcome.This study was approved by the Ethics Committee of the Chinese PLA General Hospital,China(approval No.S2014-096-01)on October 11,2014.展开更多
BACKGROUND: Hepatic artery thrombosis (HAT) is a frequent complication following liver transplantation, but it is rarely caused by arcuate ligament compression of the celiac artery. This article mainly describes our e...BACKGROUND: Hepatic artery thrombosis (HAT) is a frequent complication following liver transplantation, but it is rarely caused by arcuate ligament compression of the celiac artery. This article mainly describes our experience in managing a patient with celiac artery stenosis and HAT after liver transplantation. METHODS: A 44-year-old man with a 15-year history of hepatitis B was admitted to our hospital for hepatocellular carcinoma. Before the operatiori, he received transarterial chemoembolization once, and pretransplant MR angiography indicated a suspected stenosis at the initiation of the celiac artery, while color Doppler showed normal blood flow in the arterial system. In this case, orthotopic liver transplantation was performed for radical cure of hepatocellular carcinoma. However, B-ultrasonography detected poor blood flow in the intra- and extra-hepatic artery on the first posttransplant day, and during exploratory laparotomy a thrombus was found in the hepatic artery. Thus, re-transplantation was conducted with a bypass between the graft hepatic artery and the recipient abdominal aorta with the donor's splenic artery. RESULTS: The patient made an uneventful recovery and color Doppler showed good blood flow in the artery and portal system. Histology confirmed extensive thrombosis in the left and right hepatic artery of the explanted graft, indicating HAT. CONCLUSIONS: Although HAT caused by celiac trunk compression is rarely reported in liver transplantation, the diagnosis should be considered in patients with pretransplant hepatic artery stenosis on angiography and abnormal blood flow on B-ultrasonography. Once HAT is formed, treatment such as thrombectomy or retransplantation should be performed as early as possible.展开更多
Despite its clinical importance, the underlying central mechanisms of pruritic behaviors are poorly understood. To investigate the role of nociceptive arcuate nucleus neurons in chloro-quine-induced pruritic behaviors...Despite its clinical importance, the underlying central mechanisms of pruritic behaviors are poorly understood. To investigate the role of nociceptive arcuate nucleus neurons in chloro-quine-induced pruritic behaviors in mice, we tested the effect of arcuate nucleus neurons and interscapular brown adipose tissue (IBAT) on itch produced by intradermal injection of chloroquine in the nape of the neck. Our results provide several lines of evidence for an important role of nociceptive arcuate nucleus neurons in chloroquine-induced pruritic behavior: (1) Intradermal microinjection of chloro-quine resulted in a dramatic increase in itch behaviors accompanied by the activation of c-Fos positive neurons in arcuate nucleus; (2) Microinjection of chloroquine significantly increased IBAT temperature in the mice. These findings suggested that chloroquine-induced pruritic behaviors were associated with the activity of nociceptive arcuate nucleus neurons.展开更多
The northeast Tibetan plateau contains important inlbrmation on the northeastward growth of the Tibetan plateau. It is bounded by the Ordos Block to the east, the Alxa Block to the north, and the Tibetan Plateau to th...The northeast Tibetan plateau contains important inlbrmation on the northeastward growth of the Tibetan plateau. It is bounded by the Ordos Block to the east, the Alxa Block to the north, and the Tibetan Plateau to the south （inset in Fig. 1; Tapponnier et al., 2001）, and has undergone complex intracontinental deformation during the Cenozoic. In this region, the northeast-convex arcuate structures developed northeastward, and are composed of a series of Cenozoic NW-SE-trending basin-and-range terrain, i.e., the Haiyuan-Xingrenbu basin, Tongxin basin and Hongsipu basin, the Yueliang Shan-Nanhua Shan- Huangjiawa Shan, Xiang Shan-Xiangjing Shan, Yantong Shan and Luo Shan-Niushou Shah, which is geometrically similar with the American basin-range tectonics.展开更多
AIM To investigate whether the arcuate nucleus (ARC) could modulate gastric motility, and if so, what are the mechanisms or pathways.METHODS Wistar rats, anaesthetized with urethan, parameters of stimulation and elect...AIM To investigate whether the arcuate nucleus (ARC) could modulate gastric motility, and if so, what are the mechanisms or pathways.METHODS Wistar rats, anaesthetized with urethan, parameters of stimulation and electrolytic lesion sites were determined according to the Paxinos and Watson 'ATLAS of rat brain in steriotaxic coordinate'. Intragastric pressure (IGP) and gastric motility were measured by Reybould′s method.RESULTS Electrical stimulation of ARC could obviously decrease the IGP by 42.2%±5.4%, n=15, P＜0.01, and the phasic gastric contractions disappeared. The analysis showed that the locus coeruleus (LC) and dorsal raphe (DR) nuclei may be involved in central, but without the invovement of β-endorphinergic neurons rich in the ARC, while in periphery, the peripheral neural pathways are both vagus and sympathetic nerves. The fibers in vagus may be non-cholinergic. Humoral factors may also be involved. At the receptor level, Tonic action of adrenergic nerve in the stomach is mainly inhibitory; β-receptors, which may be present on the stomach wall and mediate inhibition; and α-receptors, which come into play through vagus, mediate inhibition, but those present on the smooth muscle mediate sympathetic excitation. Microinjection of TRH into ARC could significantly increase the IGP by 183.02% (0.53kPa±0.08kPa vs 1.5kPa±0.6kPa, n=10, P＜0.001), the rate and amplitude of phasic gastric contraction were also increased (3cpm vs 6cpm-8cpm). The peripheral pathway of such excitatory effects were transmitted with cholinergic vagus nerve mediated by M-receptor.CONCLUSION ARC could modulate gastric motility biphasically, inhibitory and excitatory, depending on the nature of stimuli.展开更多
The Xuhuai fold thrust belt(XHTB)is a curved structure in the southeastern margin of the North China Craton(NCC)that has attracted great attentions due to its tectonic and petrological characteristics.However,few geop...The Xuhuai fold thrust belt(XHTB)is a curved structure in the southeastern margin of the North China Craton(NCC)that has attracted great attentions due to its tectonic and petrological characteristics.However,few geophysical studies have focused on the deep structure of this belt.In this study,we carry out a systematic demonstration of the main geophysical features that characterize the XHTB and surrounding areas.The results reveal small negative gravity and magnetic anomalies,thin crust and lithosphere,lower shear velocity and shallower earthquake epicenters relative to other areas of the NCC,collectively indicating a lithospheric-scale rheological anomaly at this belt.The magnetic alignments show a trend similar to that of geological units in southeastern NCC and adjacent areas,although they differ from the SKS-splitting fast polarization directions,except in the Qinling-Dabie orogen where a vertical coherent deformation of the crust and mantle may be involved there.Based on the geophysical data,we propose a detachment-controlled model,which was caused by the different detachment depth/strength,for the formation of XHTB to explain its arcuate shape as well as the magnetic alignments,thus providing new insight into the deep processes of southeastern NCC.展开更多
The median arcuate ligament syndrome(MALS)is recognized as a rare clinical entity,characterized by chronic post-prandial abdominal pain,nausea,vomiting,and unintentional weight loss.Due to its vague symptomatology,it ...The median arcuate ligament syndrome(MALS)is recognized as a rare clinical entity,characterized by chronic post-prandial abdominal pain,nausea,vomiting,and unintentional weight loss.Due to its vague symptomatology,it is mainly regarded as a diagnosis of exclusion.Patients can often be misdiagnosed for several years before a correct diagnosis is established,also due to a medical team’s clinical suspicion.We present a case series of two patients who suffered from MALS and were treated successfully.The first patient is a 32-year-old woman,presenting with post-prandial abdominal pain and weight loss that have lasted for the past ten years.The second patient,a 50-year-old woman,presented with similar symptomatology,with the symptoms lasting for the last five years.Both cases were treated by laparoscopic division of the median arcuate ligament fibers,which alleviated extrinsic pressure from the celiac artery.Previous cases of MALS were retrieved from PubMed,to assemble a better diagnostic algorithm and propose a treatment method of choice.The literature review suggests an angiography with a respiratory variation protocol as the diagnostic modality of choice,along with the laparoscopic division of the median arcuate ligament fibers as the proposed treatment of choice.展开更多
Through the analysis and 2-D inversion for the 5 profiles in Haiyuan arcuate tectonic region (105°-107°E, 36°-37.5°N) in the northeastern margin of Qinghai-Xizang Plateau, we have obtained the elec...Through the analysis and 2-D inversion for the 5 profiles in Haiyuan arcuate tectonic region (105°-107°E, 36°-37.5°N) in the northeastern margin of Qinghai-Xizang Plateau, we have obtained the electric structure within a range of 160 km in width (east-west) and 60 km in depth in the studied area. The results show that the crustal electric structure can be divided into 6 sections, corresponding respectively to Xiji basin (I), Xihuashan-Nanhuashan uplift (II), Xingrenbu-Haiyuan basin (III), Zhongwei-Qingshuihe basin (IV), Zhongning-Hongsibu basin (V) and west-margin zone of Ordos (VI) from the southwest to the northeast. The crustal electric structure is characterized by a broom-shaped pattern, which scatters to the northwest and shrinks to the southeast. The structures in the top part of Haiyuan arcuate tectonic region are complete and large, however, they diminish from the arc top to the northwest and southeast ends. In the depth from 0 km to 10 km, the resistivity is high in the sections II and VI, but relatively low in the other four sections, showing a similar pattern of basin depression. The electrical basement in the section III is the deepest, displaying a dustpan shape that is deep in the southwest and shallow in the northeast. A series of discontinuous zones with high conductivity exist in the middle-lower crust in Haiyuan arcuate tectonic region, which is possibly related to the moderate and strong earthquakes in the region. The resistivity distribution in the focal area of the 1920 Haiyuan earthquake is significantly heterogeneous with an obviously high conductivity zone near the hypocenter regime.展开更多
Essential language sites and the arcuate fasciculus（AF） have been extensively researched. However, the relationship between them remains insufficiently studied,especially in healthy people. Navigated transcranial ma...Essential language sites and the arcuate fasciculus（AF） have been extensively researched. However, the relationship between them remains insufficiently studied,especially in healthy people. Navigated transcranial magnetic stimulation（n TMS） is increasingly used in language mapping. While enjoying the advantage of non-invasiveness, it is also capable of inducing a virtual lesion in the brain. Thus, it offers the possibility of using the virtuallesion method to study the healthy brain. This study combined n TMS and diffusion tensor imaging（DTI）tractography to investigate the relationship between essential language sites and the AF in 30 healthy right-handedvolunteers. A total of 143 essential language sites were identified using n TMS, and a total of 175 AF terminations were identified using DTI tractography. Sixty-six sites had a direct correlation with the AF, accounting for 46% of the total essential language sites. Forty-seven AF terminations harbored essential language sites, accounting for 27% of the total AF terminations. Upon data rendering to the cortical parcellation system, a region-related heterogeneity of the correlation rate was found. This study provides the first data on the relationship between essential language sites and the AF in healthy adults.展开更多
BACKGROUND： The arcuate nucleus, when damaged in young rats, can lead to pathological changes in adults, such as osteoporosis. Ovariectomized rats suffer from osteoporosis at eight weeks following surgery and the num...BACKGROUND： The arcuate nucleus, when damaged in young rats, can lead to pathological changes in adults, such as osteoporosis. Ovariectomized rats suffer from osteoporosis at eight weeks following surgery and the number of β -endorphin immunoreactive neurons in the arcuate nucleus of the hypothalamus is significantly decreased. OBJECTIVE： To establish a rat model of osteoporosis using ovariectomy and to explore changes in the number of β-endorphin neurons and to correlate any such change with serum hormone levels in response to exercise or rest. DESIGN, TIME AND SETTING： The completely randomized block design, neural morphology study was performed at the Key Laboratory of Physiology, Guangdong Medical College, China between March 2004 and January 2005. MATERIALS： Sixteen healthy female rats were selected for ovariectomy. METHODS： Following model establishment, rats were assigned to either rest or exercise groups and each rat was housed individually. Rats in the exercise group underwent an exercise regimen using a treadmill. MAIN OUTCOME MEASURES： Eight weeks following exercise, radioimmunoassay was performed to detect serum growth hormone, estrogen and osteocalcin levels. Immunohistochemistry was used to measure changes in the number of β -endorphin neurons in the arcuate nucleus of the hypothalamus. Changes in bone metabolism were assessed using bone histomorphometry. RESULTS： In the exercise group, the β -endorphin immunoreactive neurons were high in number, darkly stained, and the nucleus was not obvious. In the rest group, the β -endorphin immunoreactive neurons were low in number and lightly stained. The number of β-endorphin immunoreactive neurons in the exercise group was higher compared with the rest group （t = 2.83, P 〈 0.05）. Estrogen levels were similar between the rest and exercise groups （P 〉 0.05）. Serum osteocalcin and growth hormone levels were significantly higher in the exercise group compared with the rest group （t = 2.78, 2.32, P 〈 0.05）. Compared with the rest group, the percentage of trabecular bone area, trabecular thickness, and trabecular number were significantly increased, but trabecular separation was significantly reduced （t=2.48, 2.57, 2.32, 3.06, P 〈 0.05） in the exercise group. In the exercise group, the trabeculae of the tibia were arranged regularly and were high in number. In the rest group, the trabeculae of the tibia were organized in a disorderly manner and were low in number, with many fat particles. CONCLUSION： Exercise promotes bone growth and delays osteoporosis by inducing an increase in the number of β-endorphin immunoreactive neurons in the arcuate nucleus of the hypothalamus and by increasing serum growth hormone and osteocalcin levels.展开更多
Stress is an inevitable interference factor that seriously affects health.Listening to music is an economical,noninvasive,and highly accepted tool for easing stress.However,physiological studies investigating the abil...Stress is an inevitable interference factor that seriously affects health.Listening to music is an economical,noninvasive,and highly accepted tool for easing stress.However,physiological studies investigating the ability of music to reduce stress in daily life are limited.We established rat models of chronic immobilization stress(CIS)to observe changes in the hypothalamic arcuate nucleus(ARC)neurons involved in the regulation of food intake and the effect of comfortable classical music exposure.Twenty-one days of stress resulted in decreased food intake and delayed body weight gain,up-regulation of leptin receptor(Ob-R),cocaine-and amphetamine-regulated transcript(CART),proopiomelanocortin(POMC),and alpha-melanocyte-stimulating hormone(α-MSH)expression,and downregulation of neuropeptide Y(NPY)and agouti-related protein(AgRP)expression in the ARC.Thus,peripheral leptin entered the ARC under chronic stress conditions,bound to Ob-R,and affected downstream nerve pathways related to appetite,such as the NPY/AgRP and CART/POMC pathways.Gentle classical music played at 65 dB reversed the abnormal expression of Ob-R and NPY induced by chronic stress.Thus,listening to comfortable music improves changes in ARC neurons related to the regulation of food intake in CIS rats,and these results provide a reference for basic research regarding how music therapy alleviates stress and stress-related health issues.展开更多
The arcuate nappe structure on the north edge of the Wuliang Mountains in westernYunnan Province is a complex nappe structural system with multiple superimposed structures.The autochthonous system is a WNW-trending ar...The arcuate nappe structure on the north edge of the Wuliang Mountains in westernYunnan Province is a complex nappe structural system with multiple superimposed structures.The autochthonous system is a WNW-trending arcuate fold belt consisting of the Jurassic andCretaceous and the allochthonous system is mainly composed of Upper Triassic rocks. Generally,the nappe structure moved from south to north, with the hanging wall thrusting in a WNW direc-tion for a distance of over 10km. The deep nappe structural system was formed at depths ofabout 5-10km in an environment not exceeding the greenschist facies. It occurred in theOligocene (about 40-20 Ma).展开更多
Alterations of proopiomelanocortin (POMC) rnRNA level in the hypothalamic arcuatenucleus were studied in rats grouped under 6h, 24h l 72h, 96h and 96h (EAX2 ) after elec-troacupuncture(EA) using rnolecular hybridizati...Alterations of proopiomelanocortin (POMC) rnRNA level in the hypothalamic arcuatenucleus were studied in rats grouped under 6h, 24h l 72h, 96h and 96h (EAX2 ) after elec-troacupuncture(EA) using rnolecular hybridization techniques. It was found that after EA, the levelof POMC mRNA rose significantly (P【0.001 ), a maximun being in the 72h group and declining inthe 96h group. In the 96h (EAX2 ) group, where EA was given at the beginning of the 72nd hour after the first one, instead of declining, the mRNA leve1 rose again. The findings may provide an expla-nation for the long postueffect of EA and its accumulation.展开更多
Objective To introduce a new generating method for the machining of a cylindrical gear with symmetric arcuate tooth trace. Methods Adopting this method, the key problems of mismatch control and manufacturing of symm...Objective To introduce a new generating method for the machining of a cylindrical gear with symmetric arcuate tooth trace. Methods Adopting this method, the key problems of mismatch control and manufacturing of symmetric arcuate tooth trace gears are solved by using suitable cutter tilt and a new generating method with double-edge gear-wheel cutter. The machining principle is analyzed and the mathematical model of generating motion is established. Then the tooth flank equation and differential geometrical parameters are discussed. Results The minim alteration of cutter tilt will make the contact flank area change so as to satisfy the special requirements. It is easy to realize the tip relief of gearing by altering coefficients of every moving axis. Because the tooth has the arc shape, the symmetrical arcuate cylindrical gears have higher overall strength and it is easy to perform the flank grinding for high precision. Conclusion This new generating method has higher productivity. It is easy to get a perfect contact zone and fully give play to the potential bearing capacity of the gears. The symmetrical arcuate cylindrical gears can be used in highly durable and heavy duty gearing applications.展开更多
文摘BACKGROUND A 56-year-old female presented with acute abdominal pain due to a ruptured pseudoaneurysm associated with median arcuate ligament syndrome(MALS),a rare condition caused by the compression of the celiac artery by the median arcuate ligament(MAL),potentially leading to ischemia,aneurysm formation,and rupture.CASE SUMMARY Computed tomography revealed a retroperitoneal hematoma,celiac artery stenosis,and two aneurysms in the inferior pancreaticoduodenal artery.Hemo-stasis was achieved using transcatheter arterial embolization.However,15 days after embolization,the patient developed duodenal stenosis,manifesting as gastric distension and nausea without abdominal pain.Endoscopy revealed mucosal edema and luminal narrowing of the duodenum.Conservative treatment was ineffective,and the patient underwent MAL transection and gastrojejun-ostomy.She recovered uneventfully,and follow-up at 4 months showed complete resolution of duodenal stenosis and no recurrence.CONCLUSION This case highlights the importance of the early diagnosis and multidisciplinary management of MALS.
基金Supported by Grant-in-Aid for Scientific Research (B) (18390065, 20390061) that on Priority Areas (15081101) from Japan Society for the Promotion of Science (JSPS)+2 种基金a grant from the 21st century Center of Excellence (COE) program, an Insulin Research Award from Novo Nordisk Pharma Ltd.a grant from Japan Diabetes Foundationa grant from the Smoking Research Foundation to TY
文摘AIM： To explore the mechanism for interactions of leptin with ghrelin and orexin in the arcuate nucleus （ARC） activating neuropeptide Y （NPY） neurons during physiological regulation of feeding, METHODS： Single neurons from ARC of adult rats with matured feeding function were isolated. [Ca2＋]i was measured to monitore their activities. The time course of leptin effects on ghrelin-induced versus orexin-induced [Ca2＋]i increases in NPY neurons was studied. RESULTS： Administration of ghrelin or orexin-A at 101~ mol/L increased cytosolic Ca2~ concentration （[Ca2＋]~） in NPY neurons isolated from the ARC of adult rats. Upon administration of leptin at 10^-14-10^-12 mol/L, ghrelin-induced [Ca2＋]i increases were initially （〈 10 min） inhibited but later restored, exhibiting a transient pattern of inhibition. In contrast, orexin-induced [Ca2＋]i increases were inhibited by leptin in a long- lasting manner. Furthermore, a prior administration of leptin inhibited orexin action but not ghrelin action to increase ICa 2＋li, CONCLUSION： Leptin counteracted ghrelin effects transiently and orexin effects long-lastingly in NPY neurons. The transient property with which leptin counteracts ghrelin action in NPY neurons may allow the fasting-associated increase in ghrelin levels to activate NPY neurons in the presence of physiological leptin and to stimulate feeding.
文摘Purpose: The purpose of this study was to compare the deterministic and probabilistic tracking methods of diffusion tensor white matter fiber tractography in patients with brain tumors. Materials and Methods: We identified 29 patients with left brain tumors ciculus was reconstructed using a deterministic Fiber Assignment by Continuous Tracking (FACT) algorithm and a probabilistic method based on an extended Monte Carlo Random Walk algorithm. Tracking was controlled using two ROIs corresponding to Broca’s and Wernicke’s areas. Tracts in tumoraffected hemispheres were examined for extension between Broca’s and Wernicke’s areas, anterior-posterior length and volume, and compared with the normal contralateral tracts. Results: Probabilistic tracts displayed more complete anterior extension to Broca’s area than did FACT tracts on the tumor-affected and normal sides (p rs.
文摘In patients undergoing pancreaticoduodenectomy(PD),unrecognized hemodynamically significant celiac axis(CA) stenosis impairs hepatic arterial flow by suppressing the collateral pathways supplying arterial flow from the superior mesenteric artery and leads to serious hepatobiliary complications due to liver and biliary ischemia, with a high rate of mortality. CA stenosis is usually due to an extrinsic compression by a previously asymptomatic median arcuate ligament(MAL). MAL is diagnosed by computerized tomography in about 10% of the candidates for PD, but only half are found to be hemodynamically significant during the gastroduodenal artery clamping test with Doppler assessment, which is mandatory before any resection. MAL release is usually efficient to restore an adequate liver blood inflow and prevent ischemic complications. In cases of failure in MAL release, postponed PD with secondary stenting of the CA and reoperation for PD should be considered as an alternative to immediate hepatic artery re-construction, which involves the risk of postoperative thrombosis of the arterial reconstruction. We recently used this two-stage strategy in a patient undergoing surgery for pancreatic adenocarcinoma.
基金Supported by independent research grant from Alcon(IIT#34114517)。
文摘AIM:To evaluate corneal astigmatic outcomes of femtosecond laser-assisted arcuate keratotomies(FAKs)combined with femtosecond-laser assisted cataract surgery(FLACS)over 12mo follow-up.METHODS:Totally 145 patients with bilateral cataracts and no ocular co-morbidities were recruited to a singlecentre,single-masked,prospective randomized controlled trial(RCT)comparing two monofocal hydrophobic acrylic intraocular lenses.Eyes with corneal astigmatism(CA)of>0.8 dioptres(D)received unpaired,unopened,surface penetrating FAKs at the time of FLACS.Visual acuity,subjective refraction and Scheimpflug tomography were recorded at 1,6,and 12mo.Alpins vectoral analyses were performed.RESULTS:Fifty-one patients(61 eyes),mean age 68.2±9.6y[standard deviation(SD)],received FAKs.Sixty eyes were available for analysis,except at 12mo when 59 attended.There were no complications due to FAKs.Mean pre-operative CA was 1.13±0.20 D.There was a reduction of astigmatism at all post-operative visits(residual CA 1mo:0.85±0.42 D,P=0.0001;6mo:0.86±0.35 D,P=0001;and 12mo:0.90±0.39,P=0.0001).Alpins indices remained stable over 12mo.Overall,the cohort was under-corrected at all time points.At 12mo,61%of eyes were within±15 degrees of pre-operative astigmatic meridian.CONCLUSION:Unpaired unopened penetrating FAKs combined with on-axis phacoemulsification are safe but minimally effective.CA is largely under-corrected in this cohort using an existing unmodified nomogram.The effect of arcuate keratotomies on CA remained stable over 12mo.
基金Clinical Research Fostering Fund of Chinese PLA General Hospital in China,No.2017FC-TSYS-2012(to FYL)Youth Program of the Natural Science Foundation of Hainan Province of China,No.819QN378(to FYL)+2 种基金the National Natural Science Foundation of China,No.81771481(to XLC)China National Key R&D Program,No.2018YFC1312602(to XLC)National Clinical Research Center for Geriatric Diseases of China,No.NCRCGPLAGH-2017007(to XLC)。
文摘The arcuate fasciculus is a critical component of the neural substrate of human language function.Surgical resection of glioma adjacent to the arcuate fasciculus likely damages this region.In this study,we evaluated the outcome of surgical resection of glioma adjacent to the arcuate fasciculus under the guidance of magnetic resonance imaging and diffusion tensor imaging,and we aimed to identify the risk factors for postoperative linguistic deficit.In total,54 patients with primary glioma adjacent to the arcuate fasciculus were included in this observational study.These patients comprised 38 men and 16 women(aged 43±11 years).All patients underwent surgical resenction of glioma under the guidance of magnetic resonance imaging and diffusion tensor imaging.Intraoperative images were updated when necessary for further resection.The gross total resection rate of the 54 patients increased from 38.9%to 70.4%by intraoperative magnetic resonance imaging.Preoperative language function and glioma-to-arcuate fasciculus distance were associated with poor language outcome.Multivariable logistic regression analyses showed that glioma-to-arcuate fasciculus distance was the major independent risk factor for poor outcome.The cutoff point of glioma-to-arcuate fasciculus distance for poor outcome was 3.2 mm.These findings suggest that intraoperative magnetic resonance imaging combined with diffusion tensor imaging of the arcuate fasciculus can help optimize tumor resection and result in the least damage to the arcuate fasciculus.Notably,glioma-to-arcuate fasciculus distance is a key independent risk factor for poor postoperative language outcome.This study was approved by the Ethics Committee of the Chinese PLA General Hospital,China(approval No.S2014-096-01)on October 11,2014.
文摘BACKGROUND: Hepatic artery thrombosis (HAT) is a frequent complication following liver transplantation, but it is rarely caused by arcuate ligament compression of the celiac artery. This article mainly describes our experience in managing a patient with celiac artery stenosis and HAT after liver transplantation. METHODS: A 44-year-old man with a 15-year history of hepatitis B was admitted to our hospital for hepatocellular carcinoma. Before the operatiori, he received transarterial chemoembolization once, and pretransplant MR angiography indicated a suspected stenosis at the initiation of the celiac artery, while color Doppler showed normal blood flow in the arterial system. In this case, orthotopic liver transplantation was performed for radical cure of hepatocellular carcinoma. However, B-ultrasonography detected poor blood flow in the intra- and extra-hepatic artery on the first posttransplant day, and during exploratory laparotomy a thrombus was found in the hepatic artery. Thus, re-transplantation was conducted with a bypass between the graft hepatic artery and the recipient abdominal aorta with the donor's splenic artery. RESULTS: The patient made an uneventful recovery and color Doppler showed good blood flow in the artery and portal system. Histology confirmed extensive thrombosis in the left and right hepatic artery of the explanted graft, indicating HAT. CONCLUSIONS: Although HAT caused by celiac trunk compression is rarely reported in liver transplantation, the diagnosis should be considered in patients with pretransplant hepatic artery stenosis on angiography and abnormal blood flow on B-ultrasonography. Once HAT is formed, treatment such as thrombectomy or retransplantation should be performed as early as possible.
基金supported by grants from the National Natural Science Foundation of China (No.81071307,No.81271766)
文摘Despite its clinical importance, the underlying central mechanisms of pruritic behaviors are poorly understood. To investigate the role of nociceptive arcuate nucleus neurons in chloro-quine-induced pruritic behaviors in mice, we tested the effect of arcuate nucleus neurons and interscapular brown adipose tissue (IBAT) on itch produced by intradermal injection of chloroquine in the nape of the neck. Our results provide several lines of evidence for an important role of nociceptive arcuate nucleus neurons in chloroquine-induced pruritic behavior: (1) Intradermal microinjection of chloro-quine resulted in a dramatic increase in itch behaviors accompanied by the activation of c-Fos positive neurons in arcuate nucleus; (2) Microinjection of chloroquine significantly increased IBAT temperature in the mice. These findings suggested that chloroquine-induced pruritic behaviors were associated with the activity of nociceptive arcuate nucleus neurons.
基金supported by research grants from China Geological Survey (CGS) (No.1212011120100,1212011120099 and 1212011220259)
文摘The northeast Tibetan plateau contains important inlbrmation on the northeastward growth of the Tibetan plateau. It is bounded by the Ordos Block to the east, the Alxa Block to the north, and the Tibetan Plateau to the south （inset in Fig. 1; Tapponnier et al., 2001）, and has undergone complex intracontinental deformation during the Cenozoic. In this region, the northeast-convex arcuate structures developed northeastward, and are composed of a series of Cenozoic NW-SE-trending basin-and-range terrain, i.e., the Haiyuan-Xingrenbu basin, Tongxin basin and Hongsipu basin, the Yueliang Shan-Nanhua Shan- Huangjiawa Shan, Xiang Shan-Xiangjing Shan, Yantong Shan and Luo Shan-Niushou Shah, which is geometrically similar with the American basin-range tectonics.
文摘AIM To investigate whether the arcuate nucleus (ARC) could modulate gastric motility, and if so, what are the mechanisms or pathways.METHODS Wistar rats, anaesthetized with urethan, parameters of stimulation and electrolytic lesion sites were determined according to the Paxinos and Watson 'ATLAS of rat brain in steriotaxic coordinate'. Intragastric pressure (IGP) and gastric motility were measured by Reybould′s method.RESULTS Electrical stimulation of ARC could obviously decrease the IGP by 42.2%±5.4%, n=15, P＜0.01, and the phasic gastric contractions disappeared. The analysis showed that the locus coeruleus (LC) and dorsal raphe (DR) nuclei may be involved in central, but without the invovement of β-endorphinergic neurons rich in the ARC, while in periphery, the peripheral neural pathways are both vagus and sympathetic nerves. The fibers in vagus may be non-cholinergic. Humoral factors may also be involved. At the receptor level, Tonic action of adrenergic nerve in the stomach is mainly inhibitory; β-receptors, which may be present on the stomach wall and mediate inhibition; and α-receptors, which come into play through vagus, mediate inhibition, but those present on the smooth muscle mediate sympathetic excitation. Microinjection of TRH into ARC could significantly increase the IGP by 183.02% (0.53kPa±0.08kPa vs 1.5kPa±0.6kPa, n=10, P＜0.001), the rate and amplitude of phasic gastric contraction were also increased (3cpm vs 6cpm-8cpm). The peripheral pathway of such excitatory effects were transmitted with cholinergic vagus nerve mediated by M-receptor.CONCLUSION ARC could modulate gastric motility biphasically, inhibitory and excitatory, depending on the nature of stimuli.
基金supported by the National Key R&D Program of China(No.2016YFC0600402)the National Natural Science Foundation of China(Nos.41874106,42021002)+1 种基金the Youth Innovation Promotion Association of CAS(No.YIPA2018385)the project from Guangdong Province(No.2019QN01H101)。
文摘The Xuhuai fold thrust belt(XHTB)is a curved structure in the southeastern margin of the North China Craton(NCC)that has attracted great attentions due to its tectonic and petrological characteristics.However,few geophysical studies have focused on the deep structure of this belt.In this study,we carry out a systematic demonstration of the main geophysical features that characterize the XHTB and surrounding areas.The results reveal small negative gravity and magnetic anomalies,thin crust and lithosphere,lower shear velocity and shallower earthquake epicenters relative to other areas of the NCC,collectively indicating a lithospheric-scale rheological anomaly at this belt.The magnetic alignments show a trend similar to that of geological units in southeastern NCC and adjacent areas,although they differ from the SKS-splitting fast polarization directions,except in the Qinling-Dabie orogen where a vertical coherent deformation of the crust and mantle may be involved there.Based on the geophysical data,we propose a detachment-controlled model,which was caused by the different detachment depth/strength,for the formation of XHTB to explain its arcuate shape as well as the magnetic alignments,thus providing new insight into the deep processes of southeastern NCC.
文摘The median arcuate ligament syndrome(MALS)is recognized as a rare clinical entity,characterized by chronic post-prandial abdominal pain,nausea,vomiting,and unintentional weight loss.Due to its vague symptomatology,it is mainly regarded as a diagnosis of exclusion.Patients can often be misdiagnosed for several years before a correct diagnosis is established,also due to a medical team’s clinical suspicion.We present a case series of two patients who suffered from MALS and were treated successfully.The first patient is a 32-year-old woman,presenting with post-prandial abdominal pain and weight loss that have lasted for the past ten years.The second patient,a 50-year-old woman,presented with similar symptomatology,with the symptoms lasting for the last five years.Both cases were treated by laparoscopic division of the median arcuate ligament fibers,which alleviated extrinsic pressure from the celiac artery.Previous cases of MALS were retrieved from PubMed,to assemble a better diagnostic algorithm and propose a treatment method of choice.The literature review suggests an angiography with a respiratory variation protocol as the diagnostic modality of choice,along with the laparoscopic division of the median arcuate ligament fibers as the proposed treatment of choice.
基金National Natural Science Foundation of China (40374032), State Key Basic Research Development and Program-ming Project (95-13-02-02) and Joint Seismological Science Foundation of China (102088).
文摘Through the analysis and 2-D inversion for the 5 profiles in Haiyuan arcuate tectonic region (105°-107°E, 36°-37.5°N) in the northeastern margin of Qinghai-Xizang Plateau, we have obtained the electric structure within a range of 160 km in width (east-west) and 60 km in depth in the studied area. The results show that the crustal electric structure can be divided into 6 sections, corresponding respectively to Xiji basin (I), Xihuashan-Nanhuashan uplift (II), Xingrenbu-Haiyuan basin (III), Zhongwei-Qingshuihe basin (IV), Zhongning-Hongsibu basin (V) and west-margin zone of Ordos (VI) from the southwest to the northeast. The crustal electric structure is characterized by a broom-shaped pattern, which scatters to the northwest and shrinks to the southeast. The structures in the top part of Haiyuan arcuate tectonic region are complete and large, however, they diminish from the arc top to the northwest and southeast ends. In the depth from 0 km to 10 km, the resistivity is high in the sections II and VI, but relatively low in the other four sections, showing a similar pattern of basin depression. The electrical basement in the section III is the deepest, displaying a dustpan shape that is deep in the southwest and shallow in the northeast. A series of discontinuous zones with high conductivity exist in the middle-lower crust in Haiyuan arcuate tectonic region, which is possibly related to the moderate and strong earthquakes in the region. The resistivity distribution in the focal area of the 1920 Haiyuan earthquake is significantly heterogeneous with an obviously high conductivity zone near the hypocenter regime.
基金supported in part by grants from the National Natural Science Foundation of China(81272782 and 81472352)the Chinese Society of Neuro-oncology,Chinese AntiCancer Association(CSNO2014MSD01)Special Funds for Instruments of the National Natural Science Foundation of China(81127003)
文摘Essential language sites and the arcuate fasciculus（AF） have been extensively researched. However, the relationship between them remains insufficiently studied,especially in healthy people. Navigated transcranial magnetic stimulation（n TMS） is increasingly used in language mapping. While enjoying the advantage of non-invasiveness, it is also capable of inducing a virtual lesion in the brain. Thus, it offers the possibility of using the virtuallesion method to study the healthy brain. This study combined n TMS and diffusion tensor imaging（DTI）tractography to investigate the relationship between essential language sites and the AF in 30 healthy right-handedvolunteers. A total of 143 essential language sites were identified using n TMS, and a total of 175 AF terminations were identified using DTI tractography. Sixty-six sites had a direct correlation with the AF, accounting for 46% of the total essential language sites. Forty-seven AF terminations harbored essential language sites, accounting for 27% of the total AF terminations. Upon data rendering to the cortical parcellation system, a region-related heterogeneity of the correlation rate was found. This study provides the first data on the relationship between essential language sites and the AF in healthy adults.
文摘BACKGROUND： The arcuate nucleus, when damaged in young rats, can lead to pathological changes in adults, such as osteoporosis. Ovariectomized rats suffer from osteoporosis at eight weeks following surgery and the number of β -endorphin immunoreactive neurons in the arcuate nucleus of the hypothalamus is significantly decreased. OBJECTIVE： To establish a rat model of osteoporosis using ovariectomy and to explore changes in the number of β-endorphin neurons and to correlate any such change with serum hormone levels in response to exercise or rest. DESIGN, TIME AND SETTING： The completely randomized block design, neural morphology study was performed at the Key Laboratory of Physiology, Guangdong Medical College, China between March 2004 and January 2005. MATERIALS： Sixteen healthy female rats were selected for ovariectomy. METHODS： Following model establishment, rats were assigned to either rest or exercise groups and each rat was housed individually. Rats in the exercise group underwent an exercise regimen using a treadmill. MAIN OUTCOME MEASURES： Eight weeks following exercise, radioimmunoassay was performed to detect serum growth hormone, estrogen and osteocalcin levels. Immunohistochemistry was used to measure changes in the number of β -endorphin neurons in the arcuate nucleus of the hypothalamus. Changes in bone metabolism were assessed using bone histomorphometry. RESULTS： In the exercise group, the β -endorphin immunoreactive neurons were high in number, darkly stained, and the nucleus was not obvious. In the rest group, the β -endorphin immunoreactive neurons were low in number and lightly stained. The number of β-endorphin immunoreactive neurons in the exercise group was higher compared with the rest group （t = 2.83, P 〈 0.05）. Estrogen levels were similar between the rest and exercise groups （P 〉 0.05）. Serum osteocalcin and growth hormone levels were significantly higher in the exercise group compared with the rest group （t = 2.78, 2.32, P 〈 0.05）. Compared with the rest group, the percentage of trabecular bone area, trabecular thickness, and trabecular number were significantly increased, but trabecular separation was significantly reduced （t=2.48, 2.57, 2.32, 3.06, P 〈 0.05） in the exercise group. In the exercise group, the trabeculae of the tibia were arranged regularly and were high in number. In the rest group, the trabeculae of the tibia were organized in a disorderly manner and were low in number, with many fat particles. CONCLUSION： Exercise promotes bone growth and delays osteoporosis by inducing an increase in the number of β-endorphin immunoreactive neurons in the arcuate nucleus of the hypothalamus and by increasing serum growth hormone and osteocalcin levels.
基金the National Natural Science Foundation of China(No.81673881 and No.81202644)the Natural Science Foundation of Hebei Province(No.H2016423049)the Scientific Research Project of Hebei Administration of Traditional Chinese Medicine(No.2020045).
文摘Stress is an inevitable interference factor that seriously affects health.Listening to music is an economical,noninvasive,and highly accepted tool for easing stress.However,physiological studies investigating the ability of music to reduce stress in daily life are limited.We established rat models of chronic immobilization stress(CIS)to observe changes in the hypothalamic arcuate nucleus(ARC)neurons involved in the regulation of food intake and the effect of comfortable classical music exposure.Twenty-one days of stress resulted in decreased food intake and delayed body weight gain,up-regulation of leptin receptor(Ob-R),cocaine-and amphetamine-regulated transcript(CART),proopiomelanocortin(POMC),and alpha-melanocyte-stimulating hormone(α-MSH)expression,and downregulation of neuropeptide Y(NPY)and agouti-related protein(AgRP)expression in the ARC.Thus,peripheral leptin entered the ARC under chronic stress conditions,bound to Ob-R,and affected downstream nerve pathways related to appetite,such as the NPY/AgRP and CART/POMC pathways.Gentle classical music played at 65 dB reversed the abnormal expression of Ob-R and NPY induced by chronic stress.Thus,listening to comfortable music improves changes in ARC neurons related to the regulation of food intake in CIS rats,and these results provide a reference for basic research regarding how music therapy alleviates stress and stress-related health issues.
文摘The arcuate nappe structure on the north edge of the Wuliang Mountains in westernYunnan Province is a complex nappe structural system with multiple superimposed structures.The autochthonous system is a WNW-trending arcuate fold belt consisting of the Jurassic andCretaceous and the allochthonous system is mainly composed of Upper Triassic rocks. Generally,the nappe structure moved from south to north, with the hanging wall thrusting in a WNW direc-tion for a distance of over 10km. The deep nappe structural system was formed at depths ofabout 5-10km in an environment not exceeding the greenschist facies. It occurred in theOligocene (about 40-20 Ma).
文摘Alterations of proopiomelanocortin (POMC) rnRNA level in the hypothalamic arcuatenucleus were studied in rats grouped under 6h, 24h l 72h, 96h and 96h (EAX2 ) after elec-troacupuncture(EA) using rnolecular hybridization techniques. It was found that after EA, the levelof POMC mRNA rose significantly (P【0.001 ), a maximun being in the 72h group and declining inthe 96h group. In the 96h (EAX2 ) group, where EA was given at the beginning of the 72nd hour after the first one, instead of declining, the mRNA leve1 rose again. The findings may provide an expla-nation for the long postueffect of EA and its accumulation.
文摘Objective To introduce a new generating method for the machining of a cylindrical gear with symmetric arcuate tooth trace. Methods Adopting this method, the key problems of mismatch control and manufacturing of symmetric arcuate tooth trace gears are solved by using suitable cutter tilt and a new generating method with double-edge gear-wheel cutter. The machining principle is analyzed and the mathematical model of generating motion is established. Then the tooth flank equation and differential geometrical parameters are discussed. Results The minim alteration of cutter tilt will make the contact flank area change so as to satisfy the special requirements. It is easy to realize the tip relief of gearing by altering coefficients of every moving axis. Because the tooth has the arc shape, the symmetrical arcuate cylindrical gears have higher overall strength and it is easy to perform the flank grinding for high precision. Conclusion This new generating method has higher productivity. It is easy to get a perfect contact zone and fully give play to the potential bearing capacity of the gears. The symmetrical arcuate cylindrical gears can be used in highly durable and heavy duty gearing applications.
