Number Of Burrs Research Articles

An intensive study plot to investigate chestnut tree reproduction

Key messagePollination is a key step for fruit production. To provide a tool for future in-depth analysis of pollination in chestnut, we describe in detail a chestnut orchard (location, genotype, phenotype and seed-set of all trees).ContextChestnuts, which are insect-pollinated trees, have been massively planted around the world for nut production. Orchards are planted with clonal varieties selected from crosses between the European chestnuts (Castanea sativa) and Japanese chestnuts (C. crenata) or Chinese chestnuts (C. mollissima) because these two last species are tolerant to blight and ink diseases.AimsTo characterize chestnut genetic resources and accurately model male and female fitness as well as pollen exchanges in orchards, we characterized all chestnuts of the INRAE chestnut germplasm collection located near Bordeaux (France).MethodsAll chestnut trees were geolocated and genotyped using 79 SNP and 98 SSR loci. We scored their flowering phenology using chestnut BBCH scale and precisely described their phenotype (height, diameter a breast height (DBH), canopy diameter…), their capacity to produce pollen (flower type, catkins length…) and their fruit production (number of burrs, seed-set…).ResultsWe geolocated 275 trees and genotyped 273 of them. We identified 115 unique genotypes and assigned each genotype to species. To assess phenology, we evaluated 244 trees twice a week, for 6 weeks from early June to mid-July. We also described tree phenotypes with 11 variables, pollen production with 5 variables and fruit production with 3 variables. All measures were recorded in 2018 except seed set that was measured two consecutive years, in 2018 and 2019.ConclusionThe data collected is very detailed and allows modelling precisely pollen exchanges between trees. Parts of this data have been successfully published in scientific articles.Data are available at: https://data.inrae.fr/dataset.xhtml?persistentId=doi:10.15454/GSJSWWAssociated metadata are available at:https://metadata-afs.nancy.inra.fr/geonetwork/srv/fre/catalog.search#/metadata/02c5ca07-1536-4f89-9a0c-9e8d44a91287

The association of procedural variables and lipid parameters with coronary rotational atherectomy outcomes.

The aim of our study is to evaluate the association of rotational atherectomy (RA) operation procedural indices and baseline lipid parameters with the prognosis of the patients with severe coronary calcification who underwent RA. Our study population consists of 287 patients treated with RA in Fuwai Hospital from January 2013 to December 2019. We analyzed the patients' rotation procedural indices including the number of burrs, the size of burrs, approach site, the size of guiding catheter, along with the baseline level of lipoprotein(a) (Lp(a)), low-density lipoprotein-cholesterol (LDL-C) and high-sensitivity C-reactive protein (hs-CRP) to examine the association of these measurements with the prognosis of these patients using Cox regression analysis and Kaplan-Meier survival analysis. We find that during the follow-up period of 56.7 months with the median, the use of single burr in the patients who underwent RA was significantly associated with the occurrence of cumulative major adverse cardiac events (MACE) when compared with using non-single burrs [Hazard Ratio (HR) 0.43, 95% confidence interval (95% CI) 0.24-0.77, p = 0.004] from univariate Cox regression analysis; (HR 0.36, 95% CI 0.20-0.66, p = 0.001) from multivariate Cox regression analysis In addition, we find a higher event-free survival rate in the single-burr group after Kaplan-Meier survival analysis (Log rank p = 0.0033). However, there was no significant association of the size of burrs with the occurrence of MACE (HR 0.90, 95% CI 0.47-1.73, p = 0.76). Similarly, we find no significant associations between the approach site and the occurrence of MACE (HR 0.79, 95% CI 0.24-2.53, p = 0.69), the baseline Lp(a) (HR 1.07, 95% CI 0.76-1.49, p = 0.71), the level of LDL-C (HR 0.83, 95% CI 0.55-1.26, p = 0.38) or hs-CRP (HR 0.85, 95% CI 0.45-1.58, p = 0.60). We find that the patients who receive RA with a single burr have better outcomes than those who receive RA with non-single burrs. Moreover,we find that the number of burrs used in RA instead of the size of burrs, approach site, the size of guiding catheter, or baseline levels of Lp(a), LDL-C or hs-CRP had significant association with the prognosis of RA patients.

The effect of laser scanning array structural on metal-plastic connection strength

The circular array structure is fabricated on the 304 stainless steel surface by fiber laser, and it is connected with the plastic under the condition of heating and pressurizing. The effects of heating temperature, connection pressure and coverage rate on the interfacial strength of the 304 stainless steel and plastics were studied, and the optimum process parameters of heating temperature and bonding pressure are obtained. The results show that the shear force of 304 stainless steel and plastic is the strongest when the heating temperature is 400 C. The strength of the connection joint is enhanced with the increase of the connection pressure, and the shear force of the 304 stainless steel and plastic connection joint is the strongest when the pressure is 70 kN. After laser treatment, the height and quantity of burr in the circular array structure have an important influence on the connection strength between stainless steel and plastic. The number of burrs in the height range of 10–20 μm is defined as Hm, which is main factor controlling the shear strength. When the Hm value corresponding to the burr height of 10–20 μm is less than 14.82%, the metal and plastic damage from the connection joint, and the connection strength increases with the increase of Hm. When the Hm is greater than 14.82%, the connection strength between stainless steel and plastic is more than that fracture strength of the plastic. And the shear force floats between 893N and 962 N, this is consistent with the average shear fracture force of plastics 946 N. The coverage rate of laser processing area has influences on the connection strength and machining efficiency. The results show that the corresponding minimum coverage rate is 38.5% when the stainless steel and plastic connection joint is damaged at the plastic, at which time the shear force is 901 ± 14.18 N.

Dural Injury During Placement of Burrholes- Single Center Study

Background and purpose: Dural tear is one of the unpleasant complications for the neurosurgeon during craniotomy. The injury might be outer dural injury or complete dural tear in nature. With the objective to see the frequency of dural injury and to analysis the association factor this study was performed prospectively.
 Material and method: This is a Prospective analytical study over the duration of 2 months. All the consecutive patients, who operated for neurosurgical pathologies where drill burr was necessary, were included in this study. Association between age, gender, diagnosis category and number of burrs and dural injury was done using Fischer’s exact test or correlation whenever necessary.
 Result: There were total of 19 patients enrolled in the study with mean age of patient in this study was 49.11 (S.D 17.13) years. Majority of them were male (79%) and head injury (47%) was the commonest pathology in the study. correlation between number of burr and dural tear was significant
 Conclusion: There was no significant correlation between age and dural injury. However, significant correlation was seen between number of burr holes made during the procedure with dural injury.

P975Safety and clinical outcomes of rotational atherectomy: an eleven-year centre experience

Abstract Introduction Rotational atherectomy (RA) is an adjunctive tool for the management of heavily calcified coronary lesions during percutaneous coronary intervention (PCI), but the clinical outcomes remain unclear. Access site choice is also poorly defined and there is growing evidence that transradial approach (TRA) is associated with lower complications and lower mortality. Objectives To assess the safety and long-term outcomes of RA for calcified coronary lesions and to investigate the influence of vascular access site in the efficacy and safety of the procedure. Methods Retrospective single-centre study that included consecutive PCI with RA performed from January 2006 to December 2017. Endpoint was a composite of major adverse cardiac events (MACE), defined as cardiovascular death, nonfatal myocardial infarction, nonfatal stroke and target vessel revascularization, at 1- and 5-year. Results 246 procedures were included in a total of 236 patients (pts): mean age 70.1±9.7 years, 73.6% male; 36.2% had previous PCI, 12.2% vascular peripheral disease (VPD), 24% reduced left ventricle ejection fraction (LVEF) and 6.9% were under hemodialysis. PCI with RA was mostly performed due to stable angina (48.9%) and via TRA (55.3%), with a total of 371 treated segments and a median number of 1 vessel treated per intervention. The left anterior descending artery was the most frequently treated artery (67.5%). Single burr was used in 76% of cases (mean number of burrs 1.23; mean burr size 1.5 mm). Procedural success rate was 94.7%. Complications were recorded in 9.3%, with no procedure related death. Clinical follow-up was complete in 98.8% of pts at 1-year and 81.3% at 5-year (mean time 62.3±41.8 months). Survival free of MACE at 1- and 5-year were 83.7% and 73.2%, respectively. Multivariate Cox regression identified 6 independent predictors (only 1 protector) for 1-year MACE (Fig. A) and 6 independent predictors (all of increased risk) for 5-year MACE (Fig. B). TRA was protector of 1-year MACE and Kaplan-Meier curves showed benefit for both 1- and 5-year MACE occurrence (Fig. C and D), without significant difference in procedural success (p=0.92) and complications (p=0.45) rate comparing to transfemoral approach. Conclusions RA followed by stenting was a safe procedure with a high immediate success rate but an increased number of long-term cardiovascular events. Some clinical conditions, such as previous PCI, VPD and reduced LVEF, seems to adversely influence the long-term outcome while TRA appears to be protective.

27 Use of rotational atherectomy in primary pci for st-elevation myocardial infarction- a single centre 10-year experience

Introduction Rotational atherectomy (RA) during primary PCI (PPCI) for STEMI is relatively contraindicated because of the perceived increased risk of no-reflow. However, RA PPCI may sometimes be required to restore flow in heavily calcified coronary arteries. Previously only very limited observational data has described the use of RA in PPCI. Aim We report the clinical and procedural characteristics, and in hospital outcomes, of 21 patients who underwent RA PPCI at our centre between 2006 and 2016, Methods A retrospective review of the PCI database and medical records. Results 21 patients (age 78(10) years (mean (SD)), 12 men) underwent RA during PPCI (0.4% of all PPCI). 3 patients had cardiogenic shock at presentation and 2 had out of hospital cardiac arrest. Hypertension (n=19), smoking history (n=18), hypercholesterolemia (n=16), diabetes (n=6) and chronic kidney disease (n=6 with eGFR Radial access was used in 14 and femoral in 7. Initial TIMI flow grade was 0, 1, 2 and 3 in 11, 2, 1 and 7 patients respectively. The target vessel was the RCA in 14, Cx in 4, LMS in 2 and LAD in 1. All were severely calcified with visible thrombus in 13/21. The lesion length was 36(19) mm (range 12–72 mm). The vessel diameter was 2.5–2.99 mm in 5, 3–3.49 mm in 10 and 3.5–4.0 mm in 6. RA was used because of anticipated difficulty with conventional PCI in 7/21 and uncrossable/unexpandable lesions in 14/21. The number of burrs used was 1.33 (0.48) and the final burr was 1.25, 1.5, 1.75 and 2 mm in 4, 11, 4 and 1 patient respectively. The burr-to-artery ratio was The median(range) pain-to-PCI time was 180 min (114–544); door-to-PCI time 49 min (21–186, 14 patients 60 min in 5/7 patients while medical/logistic reasons contributed in the other 2. 1 patient underwent CT scanning prior to PCI; 1 underwent an urgent MDT discussion before PCI. Final flow was TIMI 3 in 19/21 and TIMI 2 in 2/21 cases. The procedure was complicated by 1 event of distal embolization. There was 1 event of peri-procedural cerebral infarction. 20/21 patients survived to hospital discharge. Conclusions Our study suggests that RA PPCI can be performed safely in a small group of predominantly elderly, complex patients in whom conventional techniques are inadequate or unsuccessful. It is associated with a relatively long procedure time but we did not experience a marked increase in no-reflow.

Research on Burrs Detection of Parts Surface Based on Threshold Segmentation

Mental cutting process, a widespread process in the machining, which can produce the maximum number of burrs. Burr detection and deburring are crucially important to safe reliability of parts. In order to avoid the effects of subjective factors effectively, and improve the production efficiency and production automation, we introduced the machine vision technique. According to the universal burrs produced in the cutting process, this paper principally studied the image segmentation, burrs feature extraction, the improvement of adaptability based on digital image processing. The authors conclude that the algorithm applied in this paper can detect the burrs information effectively, laid a solid foundation for automatic polishing, with the certain practical value.

Results of the study to determine rotablator and transluminal angioplasty strategy (STRATAS)

Rotational atherectomy is used to debulk calcified or complex coronary stenoses. Whether aggressive burr sizing with minimal balloon dilation (<1 atm) to limit deep wall arterial injury improves results is unknown. Patients being considered for elective rotational atherectomy were randomized to either an “aggressive” strategy (n = 249) (maximum burr/artery >0.70 alone, or with adjunctive balloon inflation ≤1 atm), or a “routine” strategy (n = 248) (maximum burr/artery ≤0.70 and routine balloon inflation ≥4 atm). Patient age was 62 ± 11 years. Fifty-nine percent routine and 60% aggressive strategy patients had class III to IV angina. Fifteen percent routine and 16% aggressive strategy patients had a restenotic lesion treated; lesion length was 13.6 versus 13.7 mm. Reference vessel diameter was 2.64 mm. Maximum burr size (1.8 vs 2.1 mm), burr/artery ratio (0.71 vs 0.82), and number of burrs used (1.9 vs 2.7) were greater for the aggressive strategy, p <0.0001. Final minimum lumen diameter and residual stenosis were 1.97 mm and 26% for the routine strategy versus 1.95 mm and 27% for the aggressive strategy. Clinical success was 93.5% for the routine strategy and 93.9% for the aggressive strategy. Creatine kinase-myocardial band (CK-MB) was >5 times normal in 7% of the routine versus 11% of the aggressive group. CK-MB elevation was associated with a decrease in rpm of >5,000 from baseline for a cumulative time >5 seconds, p = 0.002. At 6 months, 22% of the routine patients versus 31% of the aggressive strategy patients had target lesion revascularization. Angiographic follow-up (77%) showed minimum lumen diameter to be 1.26 mm in the routine group versus 1.16 mm in the aggressive group, and the loss index 0.54 versus 0.62. Dichotomous restenosis was 52% for the routine strategy versus 58% for the aggressive strategy. Multivariable analysis indicated that left anterior descending location (odds ratio 1.67, p = 0.02) and operator-reported excessive speed decrease >5,000 rpm (odds ratio 1.74, p = 0.01) were significantly associated with restenosis. Thus, the aggressive rotational atherectomy strategy offers no advantage over more routine burr sizing plus routine angioplasty. Operator technique reflected by an rpm decrease of >5,000 from baseline is associated with CK-MB elevation and restenosis.

Rotational atherectomy: technique, indications, results

Rotational atherectomy (Rotablation) represents one of the alternative devices to treat complex coronary artery stenoses. Rather than increasing luminal diameter by arterial stretching and plaque fracture as with balloon angioplasty, rotablation debulks atherosclerotic plaque with an abrasive diamond coated burr. The basic physical principle is differential cutting. It allows the advancing burr to selectively cut inelastic material while elastic tissue deflects away from the burr. 95% of the particles generated by the Rotablator are less than 5 microns. They are removed by the body's reticuloendothelial system. There are different strategies to perform a rotablation, regarding the number of burrs used and the final burr-to-artery ratio. An adjunctive PTCA is recommended without proof by randomized studies so far. The best indication for the Rotablator is the undilatable lesion. Lesion modification (debulking) as a method of improving vessel compliance seems to be also usefull in diffusely diseased and calcified vessels, as well as in aorto-ostial and angulated stenoses. The instent restenoses is a new indication. Randomized studies will have to proof if there is an advantage for rotablation compared to PTCA. Restenosis rates appear comparable to balloon angioplasty.

Seed and seedling studies of three Trifolium subterraneum var. brachycalycinum lines, in a predominantly summer rainfall environment

Field experiments were conducted in a predominantly summer rainfall environment to investigate burr burial, seed production, seed characteristics, seedling emergence and survival, and the effects of time of sowing on 3 Trifolium subterraneum var. brachycalycinum lines (cv. Clare and 2 local lines). Each line produced more surface than buried burrs; surface burrs were 59% (range 56-62%) of the total number of burrs recovered and produced 59% of the total seed number. Numbers of seeds per burr were similar for surface and buried burrs, however, buried seeds were 0.97 mg heavier (P&lt;0.05) than surface seeds. Storage for 5 months at 25/60�C decreased hardseed content of surface seed by 50% and buried seed by 70%. Surface and buried seeds stored at 25/25�C for 3 months prior to sowing in trays had a total emergence of &lt;10%, compared with 70% emergence for seeds stored at 25/60�C before sowing. These emergence differences reflected their levels of hardseededness. Numbers of seeds recovered from the soil were not significantly different among lines, declining from about 4200 seeds/m2 after initial seed set to 150 seeds/m2 by the following winter, a 97% decrease. Seed production in the second year increased seed reserves to about 8730 seeds/m2. With no further seed production, levels had declined by 93% in June 1990 and by 99% in May 1991. These data confirm the importance of annual seed production for persistence. Total seedling emergence in summer-autumn accounted for only 10% of the estimated seed production in each year. Seedling survival in summer-autumn 1988-89 was 92.7%, more than double the survival in 1989-90. The effect of sowing time on flowering was always significant, with time to first flower being highest (196 days) for the earliest sowing in March (P&lt;0.05), progressively decreasing (P&lt;0.05) to 108 days for the latest sowing in July. In March, April and May sowings, inflorescence numbers on the first day of flowering were similar at about 120/m2, but increased markedly (P&lt;0.05) for sowing in June or July. However, for the March and July sowings, number of inflorescences at the 9 November 1990 count, were lowest (P&lt;0.05). May or June sowings had the highest number of burrs and seeds (P&lt;0.05), indicating that these may be the best sowing times for maximum seed production in these Trifolium subterraneum var. brachycalycinum lines.

Copper nutrition of subterranean clover (Trifolium subterraneum L. cv. Seaton Park). I. Effects of copper supply on growth and development

Effects of severe and moderate copper deficiency on the development of leaves and lateral branches, on the distribution of dry weight within the plant, and on seed yield of Seaton Park subterranean clover were assessed as part of three glasshouse experiments. Copper deficiency markedly depressed top and root growth without producing any distinctive symptoms. It retarded phasic development by delaying development of leaves and lateral branches, senescence of plant parts, and flowering: it also depressed the proportion of stem plus petiole in plant tops and decreased internode elongation, pollen fertility and the number of burrs and seeds formed. As a result of its effect in delaying flowering, copper deficiency would depress seed production particularly strongly when low soil water supply shortens the growing season. The need for suitable procedures for diagnosing copper deficiency is emphasized by the lack of specific plant symptoms in this species.