Branch Feeders Research Articles

Custom shaping of distal access catheter for navigation of microcatheter into inferolateral and meningohypophyseal trunk feeders.

Navigating a microcatheter to tiny feeding arteries such as the inferolateral trunk (ILT) and meningohypophyseal trunk (MHT) of the internal carotid artery (ICA) is technically challenging because of the anatomical features of steep angulation, small diameter, and significant caliber difference from the ICA. To guide the microcatheter to these ICA side branch feeders, the authors thought that a custom shaping of the intermediate catheter would be helpful to determine the direction of the microcatheter and strongly back it up. The aim of this study was to report the detailed methodology and clinical outcomes of patients who had undergone the embolization of ILT and MHT feeders using this method. This was a retrospective study of consecutive patients with intracranial tumors and dural arteriovenous fistulas (DAVFs) who had undergone endovascular embolization. The details of the embolization procedures were examined, especially the technique of guiding a low-profile microcatheter supported by the thermoformed intermediate catheter. The authors assessed the patient background, procedural outcomes, and postoperative complications. Between October 2013 and June 2022, 43 patients with intracranial tumors and 45 with DAVFs underwent embolization at the authors' institutions. Among these cases, embolization of the ICA side branch feeder was attempted in 10 intracranial tumors and 2 DAVFs. Of these 12 patients, the microcatheter was guided deep enough for successful embolization in 11 cases (92%). Two asymptomatic arteriovenous fistulas were complicated during guidewire manipulation deep in the feeder. Yet, both disappeared completely after glue injection into the feeding artery. No spasm or dissection of the parent artery occurred during the procedure. Postoperative radiological evaluation showed no intracranial hematoma or symptomatic cerebral infarction. One patient (9%) developed permanent postoperative cranial neuropathy that gradually improved after embolization. This study revealed that custom shaping of distal access catheters is an effective technique that enabled the embolization of ILT and MHT feeders with a success rate of more than 90%.

Green Tattoo Pre-Operative Renal Embolization for Robotic-Assisted and Laparoscopic Partial Nephrectomy: A Practical Proof of a New Technique.

(1) Background: Our aim is to describe a new mixed indocyanine-non-adhesive liquid embolic agent (Onyx-18) pre-operative renal embolization technique for assisted-robotic and laparoscopic partial nephrectomy with near-infra-red fluorescence imaging. (2) Methods: Thirteen patients with biopsy-proven renal tumors underwent pre-operative mixed indocyanine-ethylene vinyl alcohol (EVOH) embolization (Green-embo) between June 2021 and August 2022. All pre-operative embolizations were performed with a super selective stop-flow technique using a balloon microcatheter to deliver an indocyanine-EVOH mixture into tertiary order arterial branch feeders and the intra-lesional vascular supply. Efficacy (evaluated as complete embolization, correct tumor mapping on infra-red fluorescence imaging and clamp-off surgery) and safety (evaluated as complication rate and functional outcomes) were primary goals. Clinical and pathological data were also collected. (3) Results: Two male and eleven female patients (mean age 72 years) received pre-operative Green-embo. The median tumor size was 29 mm (range 15-50 mm). Histopathology identified renal cell carcinoma (RCC) in 9 of the 13 (69%) patients, oncocytoma in 3 of the 13 (23%) patients and sarcomatoid RCC in 1 of the 13 (8%) patients. Lesions were equally distributed between polar, meso-renal, endo- and exophytic locations. Complete embolization was achieved in all the procedures. A correct green mapping was identified during all infra-red fluorescence imaging. All patients were discharged on the second day after the surgery. The median blood loss was 145 cc (10-300 cc). No significant differences were observed in serum creatinine levels before and after the embolization procedures. (4) Conclusions: The Green-tattoo technique based on a mixed indocyanine-non-adhesive liquid embolic agent (Onyx-18) is a safe and effective pre-operative embolization technique. The main advantages are the excellent lesion mapping for fluorescence imaging, reduction in surgical time, and definitive, complete and immediate tumor devascularization based on the deep Onyx-18 penetration, leading to a very low intra-operative blood loss.

Optimal Dispatching Strategy of Active Distribution Network for Promoting Local Consumption of Renewable Energy

Large-scale renewable energy sources (RESs) have been integrated into the active distribution network (ADN). For promoting the local consumption of RESs within ADN, an optimal dispatching strategy was proposed with two-stage hierarchical energy management framework. On the spatial boundary, a two-layer energy management framework was designed with the local optimization layer and the global optimization layer. The local optimization layer was for optimal power flow in the branch feeder with the objective functions of minimizing operation costs and maximizing the consumption of RESs. The global optimization layer was for optimal power flow in the main feeder with the objective functions of minimizing power loss and the voltage deviation of nodes. On the time scale, two-stage optimal dispatching models were established, including the day-ahead optimal models and intra-day optimal models. The day-ahead optimal models identified the operation status of the controllable units, and then the intra-day optimal models were updated with the ultra-short-term forecast results. A risk indicator was introduced to quantify the uncertainty of RES, and a non-dominated sorting genetic algorithm with elite strategy was adopted to solve the multi-objective nonlinear programming problem. An actual project in northern China was used as the testing system. The results of case studies verify that the proposed strategy can effectively realize the maximum local consumption of RESs and support the economic operation of ADN.

581 Renal Arteriovenous Fistula Percutaneous Embolization Using the Amplatzer Vascular Plug II

Abstract Introduction Renal arteriovenous fistula (AVF) is not considered a common condition; however, it can occasionally complicate with renal impairment and heart failure secondary to high cardiac output. Recently, percutaneous embolization has overcome traditional surgery as the first line of its management, because of better success rates as well as less morbidity and mortality. Case report A 68-year-old male who presented with a renal AVF post left partial nephrectomy associated with a large pseudoaneurysm. This was found on a computed tomography angiography (CTA) scan, a routine follows up for his endovascular aortic aneurysm repair. Due to the patient’s co-morbidities and to avoid the potentially fatal pseudoaneurysm rupture, a minimal invasive approach was agreed in the multidisciplinary meeting. He was treated by percutaneous transcatheter embolization using the Amplatzer Vascular Plug II (AVP-II) through a right femoral arterial access. The patient recovery was uneventful, following an overnight stay he was discharged home. CTA done four and ten months later showed the AVP-II device inside the left renal artery branch feeder with no artifacts seen. There was absence of recanalization of the AVF. In the literature, adopting the transarterial route for the renal AVF treatment with AVP-II device as a single embolotherapy device has not been reported before. Conclusions Our report display the feasibleness of AVP-II in renal AVF treatment by arterial feeder embolization, specifically in fistulas with high flow and short communication as our case in which it showed offered multiple advantages over coils and is more cost effective.

Hallucal grasping behavior in Caluromys (Didelphimorphia: Didelphidae): Implications for primate pedal grasping

A key feature in primate evolution is a foot with a divergent opposable hallucal metatarsal bearing a large peroneal process. Extant primates are characterized by a powerful hallucal grasp—an either “euprimate” or “plesiadapoid-euprimate” ancestor acquisition—that facilitates the exploitation of fine branches, an ability that increased the fitness of ancestral euprimates. In this context, the didelphid marsupial Caluromys has been used as the extant analog to this primate morphotype stage due to some morphological, ecological, and behavioral features. However, the extent to which and the positional and support contexts in which Caluromys uses powerful hallucal grasping are not known. This renders analogies to any mode of “euprimate” or “stem primate” grasping poorly substantiated. The present paper quantifies locomotor and postural behavior, support use, and associated frequencies of hallucal grasping in captive Caluromys philander via analysis of video recordings. During locomotion, Caluromys primarily used diagonal sequence walk, clamber, and climb, whereas stand, foot-hang, and bipedal stand were the dominant postures. Small, fine, horizontal, and moderately inclined branches were frequently used. Overall rates of “apparently powerful hallucal grasps” were high, but were exceptionally high during clamber, climb, foot-hang, and bipedal stand. Additionally, an “apparently powerful hallucal grasp” was very common upon fine, small, steep, and vertical branches. The extensive use of such powerful hallucal grasping provided stability and safety that enabled Caluromys to proficiently utilize fine branches of various orientations. The ability to negotiate such unstable supports, further reflected in foot anatomy, provides evidence that the morphobehavioral complex of Caluromys can serve as an extant analog to the plesiadapoid-euprimate ancestor, represented as a terminal branch feeder with effective hallucal grasping.

Analysis of electromagnetic field transient on branch feeders by numerical electromagnetic field computation

AbstractThis paper presents the fundamental surge phenomenon when a step voltage is applied to a horizontal line above the ground which has branch feeders. We study line current and voltage at joint with the method of moments that calculates electromagnetic field in frequency domain. It is widely noted that the current reflection factor changes to a third at the junction of the same three lines in conventional transmission line theory based on TEM wave, and the stepwise current reflected appears overlapping to the incident current. On the other hand, the reflected current from the joint shows the inductive characteristic or the capacitive one depending on the angle between lines, which varies gradually and not stepwise in our numerical analysis considering TM wave. The time characteristic of the voltage at joint depends on the angles also, and the peak voltage slightly exceeds the voltage by the transmission line theory. These phenomena are caused by the electromagnetic coupling between the main line and branch lines. In addition to the computer simulations, we measured the currents in the reduced‐scale model lines and the results show the validity of our analysis regarding changes of the reflected current depending on the angles. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 144(2): 1–8, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10176

線路分岐部の過渡電磁界解析

This paper presents the fundamental surge phenomenon when a step voltage is applied to a horizontal line above the ground which has branch feeders. We study line current and voltage at joint with the moment method that calculates electromagnetic field in frequency domain. It is widely noted that the current reflection factor changes to a third at the junction of same three lines in conventional transmission line theory based on TEM wave, and the stepwise current reflected appears overlapping to the incident current. On the other hand, the reflected current from the joint shows the inductive characteristic or the capacitive one depending on the angle between lines, which varies gradually and not stepwise in our numerical analysis considering TM wave. The time characteristic of the voltage at joint depends on the angles also, and the peak voltage is slightly large compared with the voltage by the transmission line theory. These phenomena are caused by the electromagnetic coupling between the main line and branch lines. In addition to the computer simulations, we measured the currents in the miniaturized model lines and the results make the validity of our analysis clear about changes of the reflected current depending on the angles.

Musculoskeletal neoplasms: preoperative evaluation with MR angiography.

To assess the ability of magnetic resonance (MR) angiography to depict vascularity of musculoskeletal neoplasms. Two-dimensional (2D) time-of-flight (TOF) MR angiography was compared with conventional arteriography during staging of musculoskeletal tumors in 23 prospective examinations. Phase-contrast (PC) MR angiography was also performed in 19 cases and evaluated as a possible supplement to 2D TOF imaging. Of named vessels, 92% in proximity to tumor were noted by blinded readers. The PC technique provided supplemental data in 47% of cases, usually related to better delineation of in-plane feeder vessels and areas with pulsatile blood flow. Of the 28 branch feeder vessels, 23 were noted on both conventional arteriograms and MR angiograms in a nonblinded review, but 16 were difficult to distinguish as feeders because of lack of associated tumor blush. MR angiography has promise to replace conventional arteriography for orthopedic preoperative planning.

Unruptured intracranial aneurysms and arteriovenous malformations: frequency of intracranial hemorrhage and relationship of lesions

Among 91 patients with unruptured intracranial arteriovenous malformations (AVM's), 16 patients had 26 unruptured intracranial saccular aneurysms. An actuarial analysis showed the risk of intracranial hemorrhage among patients with coexisting aneurysm and AVM to be 7% per year at 5 years following diagnosis compared to 1.7% for patients with AVM alone. The difference in length of survival free of hemorrhage was significant (log-rank, p less than 0.0007). Several angiographic and clinical parameters were investigated to better understand the relationship of these lesions. The aneurysms occurred in similar percentages in patients with small, medium, and large AVM's. Twenty-five aneurysms were on arteries feeding the malformation system, almost equally distributed proximally and distally. Eleven aneurysms were atypical in location, and all arose from primary or secondary branch feeders to the malformation; 24 were on enlarged feeding arteries. Eleven (16%) of the 67 patients with high-flow AVM's had associated aneurysms, compared with five (21%) of the 24 patients with low-flow AVM's. Four (16%) of 25 low-shunt malformations and 12 (18%) of 65 high-shunt malformations had associated aneurysms. All five aneurysms associated with low-shunt malformations were on a direct arterial feeder of the malformation. These data suggest that the intracranial AVM's predispose to aneurysm formation within AVM feeding systems and that the mechanism is not simply based upon the high blood flow or high arteriovenous shunt in these systems.

Insect pests of coffee with special emphasis on antestia, Antestiopsis intricata, in Ethiopa

Several Arthropod pests have been collected and identified on coffee, Coffea arabica. L. in Ethiopia, but only a few are economically important. Based on the plant part the pests feed on, they can be categorized as flower and flower bud feeders, leaf feeders, berry (fruit) feeders, twig and branch feeders borers and stem (trunk) borers.

FUNGI ASSOCIATED WITH NEMATODE AND NON-NEMATODE LESIONS ON BANANA ROOTS

Fusarium solani and a binucleate Rhizoctonia were the predominant fungi in nematode and non-nematode lesions on banana roots in Honduras and Panama. In deep lesions of the main root caused by Radopholus similis, F. solani predominated followed closely in prevalence by Rhizoctonia, whereas in shallow lesions of Helicotylenchus multicinctus, Rhizoctonia predominated and F. solani was next in frequency. On necrotic small branch feeder roots Rhizoctonia predominated. In root tip dieback F. solani was the most common, then Cephalosporium and Rhizoctonia. Other fungi obtained in from 5 to 20% of the lesions included F. roseum, Cephalosporium (if tissue was macerated or fragmented before plating), Curvularia, Trichoderma, Penicillium, Nigrospora oryzae, Cunninghamella echinulata, and Botryodiplodia theobromae. Representatives of 14 other genera were inconsistently isolated as well as several nonsporing fungi. Pythium was isolated only once and Phytophthora not at all, even when selective media were used, nor was F. oxysporum encountered. Rhizoctonia and F. solani were also common inhabitants of the surface of healthy banana roots. From 40 to 60% of the Rhizoctonia isolates invaded and often killed seedlings of Musa acuminata and some isolates stunted growth of bananas in pots of methyl bromide fumigated soil. These isolates also produced brown lesions when applied to wounded banana roots growing in a mist chamber. Their contribution to root necrosis and yield decline in banana plantations remains to be determined.

Protection of low-voltage circuits by air circuit breakers in cascade arrangement

This paper deals with and outlines a new solution to the problem of providing adequate short circuit protection for low-voltage distribution systems and circuits operating at 600 volts or less. Recent tests and field experience have dispelled the illusion that protective devices of very limited interrupting ability will satisfactorily protect any low-voltage circuit. A recently published calculating procedure makes possible the accurate determination of the short circuit currents obtainable in low voltage circuits or systems. Modern types of low-voltage air circuit breakers in a wide range of interrupting ratings are now available. While the best short circuit protection is obtained by selecting those of interrupting ratings at least equal to the calculated short circuit current, such a procedure is not always justifiable. In many instances a relatively large number of main feeder circuits, emanating from a bus fed through one or more main breakers or incoming line breakers, supply an even larger number of branch feeders. The short circuit currents obtainable at the branch-feeder breaker locations may not be materially less than those obtainable at the main bus. Yet the selection of branch feeder breakers, or possibly even main feeder breakers, with interrupting ratings high enough to match these obtainable currents, may prove completely impractical when viewed with any reasonable regard for space requirements or cost. Air circuit breakers of varying interrupting ratings, properly coordinated in design may be used in a “cascade” or series connection in such manner that in event of a severe fault, the main breakers “back-up” the smaller main feeder breakers, and these, in turn, “back-up” the branch feeder breakers. Only the main breakers need have interrupting ratings equal to the obtainable short-circuit current, yet the system is adequately protected, within the limits set forth in the paper. Cascading also makes possible a simple means of selecting air circuit breakers to provide economical yet adequate protection for relatively small installations, where a complete short-circuit study might be difficult to justify and where a poor selection of protective devices would result in either an unnecessarily expensive installation or a serious hazard — generally the latter. An application table for such installations, based upon the principle of cascade operation is included.

Protection of Low-Voltage Circuits by Air Circuit Breakers in Cascade Arrangement

This paper deals with and outlines a new solution to the problem of providing adequate short circuit protection for low-voltage distribution systems and circuits operating at 600 volts or less. Recent tests and field experience have dispelled the illusion that protective devices of very limited interrupting ability will satisfactorily protect any low-voltage circuit. A recently published calculating procedure makes possible the accurate determination of the short circuit currents obtainable in low voltage circuits or systems. Modern types of low-voltage air circuit breakers in a wide range of interrupting ratings are now available. While the best short circuit protection is obtained by selecting those of calculated short circuit current, such a procedure is not always justifiable. In many instances a relatively large number of main feeder circuits, emanating from a bus fed through one or more main breakers or incoming line breakers, supply an even larger number of branch feeders. The short circuit currents obtainable at the branch-feeder breaker locations may not be materially less than those obtainable at the main bus. Yet the selection of branch feeder breakers, or possibly even main feeder breakers, with interrupting ratings high enough to match these obtainable currents, may prove completely impractical when viewed with any reasonable regard for space requirements or cost.

Principles of audio-frequency wire broadcasting

The quantitative limitations of wireless broadcasting have stimulated an interest in alternative methods of distributing programmes to listeners. Wire broadcasting has certain basic technical and economic advantages over wireless broadcasting. Wire-broadcasting technique has been extensively applied in Holland, where 50 per cent of the Dutch listeners have their programme service laid on to the house by a wire connection. Relatively slight developments of the same nature have taken place in Great Britain.“Audio-frequency rediffusion” is the most common form of “ wire broadcasting ” existing to-day. In “audio-frequency rediffusion,” programmes originally transmitted by “wireless” are picked up by a receiver located where reception conditions are favourable, and the output of this receiver is connected, usually by landline, to the input of an amplifier which raises the level of the receiver output to a value sufficient to energize at once a thousand or more loud-speakers connected to the amplifier by a conducting network.In common practice this network is supported on house chimneys, but sometimes it is carried on poles. The consumers' branch feeders are wired in lead-covered cable.The paper analyses the effects set up by the interaction of the reactances and resistances composing the network and the loud-speakers; and it shows that the received level, particularly towards the ends of the lines, varies enormously both with loading at certain audio frequencies and with audio frequency for a given loading.Certain generalized rules are laid down to indicate how the distortions incidental to this form of wire broadcasting may be partly minimized or wholly eradicated.The analysis of the network performance allows the preparation of a specification for the amplifier necessary to supply power to the network.

Principles of audio-frequency wire broadcasting

The quantitative limitations of wireless broadcasting have stimulated an interest in alternative methods of distributing programmes to listeners. Wire broadcasting has certain basic technical and economic advantages over wireless broadcasting. Wire-broadcasting technique has been extensively applied in Holland, where 50 per cent of the Dutch listeners have their programme service laid on to the house by a wire connection. Relatively slight developments of the same nature have taken place in Great Britain.ldquo;Audio-frequency rediffusion” is the most common form of “wire broadcasting” existing to-day. In “audio-frequency rediffusion,” programmes originally transmitted by “wireless” are picked up by a receiver located where reception conditions are favourable, and the output of this receiver is connected, usually by landline, to the input of an amplifier which raises the level of the receiver output to a value sufficient to energize at once a thousand or more loud-speakers connected to the amplifier by a conducting network.In common practice this network is supported on house chimneys, but sometimes it is carried on poles. The consumersapos; branch feeders are wired in lead-covered cable.The paper analyses the effects set up by the interaction of the reactances and resistances composing the network and the loud-speakers, and it shows that the received level, particularly towards the ends of the lines, varies enormously both with loading at certain audio frequencies and with audio frequency for a given loading.Certain generalized rules are laid down to indicate how the distortions incidental to this form of wire broadcasting may be partly minimized or wholly eradicated.The analysis of the network performance allows the preparation of a specification for the amplifier necessary to supply power to the network.