Blade Insertion Research Articles

Rice grown in nutrient solution with doses of manganese and silicon

Although silicon is not recognized as a nutrient, it may benefit rice plants and may alleviate the Mn toxicity in some plant species. The dry matter yield (root, leaf, sheaths and leaf blade) and plant architecture (angle of leaf insertion and leaf arc) were evaluated in rice plants grown in nutrient solutions with three Mn doses, with and without Si addition. The treatments were arranged in a 2 x 3 factorial [with and without (2 mmol L-1) Si; three Mn doses (0.5; 2.5 and 10 µmol L-1)], in a randomized block design with 4 replications. The experimental unit was a 4 L plastic vase with 4 rice (Metica-1 cultivar) plants. Thirty nine days after keeping the seedlings in the nutrient solution the plant dry matter yield was determined; the angle of leaf insertion in the sheath and the leaf arc were measured; and the Si and Mn concentrations in roots, sheaths and leaves were determined. The analysis of variance (F test at 5 and 1 % levels) and the regression analysis (for testing plant response to Mn with the Si treatments) were performed. The Si added to the nutrient solution increased the dry matter yield of roots, sheaths and leaf blades and also decreased the angle of leaf blade insertion into the sheath and the foliar arc in the rice plant. Additionally, it ameliorated the rice plant architecture which allowed an increase in the dry matter yield. Similarly, the addition of Mn to the solution improved the architecture of the rice plants with gain in dry matter yield. As Si was added to the nutrient solution, the concentration of Mn in leaves decreased and in roots increased thus alleviating the toxic effects of Mn on the plants.

Comparison of three videolaryngoscopes: Pentax Airway Scope, C‐MAC™, Glidescope® vs the Macintosh laryngoscope for tracheal intubation*

We compared the intubating characteristics of the Pentax Airway Scope, the C-MAC and the Glidescope with those of the Macintosh laryngoscope in 400 patients without predictors of difficult intubation. We found shorter intubation times with the Airway Scope (mean (SD) 20.6 (11.5) s) compared with the C-MAC (31.9 (17.6) s) and Glidescope (31.2 (15.0) s), p < 0.001. The median (IQR [range]) score for ease of intubation was significantly lower (better) with the Airway Scope (0 (0-8.75 [0-60])) than with the C-MAC (10 (0-20 [0-90])) or Glidescope (0 (0-20 [0-80])), p < 0.001. Ease of blade insertion in the C-MAC (0 (0-0 [0-30])) was superior to that of the Airway Scope (0 (0-0 [0-70])), Macintosh (0 (0-0 [0-80])) or Glidescope (0 (0-10 [0-60])), p = 0.006. More patients had a grade 1 laryngeal view with the Airway Scope (97%) compared with the C-MAC (87%), Glidescope (78%), or Macintosh (58%), p < 0.001. There were no grade 3 laryngeal views with the Airway Scope. The three videolaryngoscopes had comparable first attempt successful intubation rates: 95% for the Airway Scope, 93% for the C-MAC and 91% for the Glidescope.

Distinguish Various Types of Defects in Bonded Wafer Pairs with the Dynamic Blade Insertion Method

This paper reports a simple and systematic experiment to distinguish various types of defects in bonded wafer pairs with the dynamic blade insertion (DBI) method and real-time observation. In addition, a type of defect was observed in bonded wafer pairs after they were heated to 1273 K and unevenly cooled. It exhibits a fairly large size with coarse Newton-ring contours in IR observation. During DBI examination, these defects exhibit quite a different behavior from other types of defects (void, dust particle, etc.) with the significant intention of resisting the movement of the approaching blade. However, this defect demonstrates a very strong bonding strength in tensile testing.

The fabrication of all-silicon micro gas chromatography columns using gold diffusion eutectic bonding

Temperature programming of gas chromatography (GC) separation columns accelerates the elution rate of chemical species through the column, increasing the speed of analysis, and hence making it a favorable technique to speedup separations in microfabricated GCs (micro-GC). Temperature-programmed separations would be preferred in an all-silicon micro-column compared to a silicon-Pyrex® micro-column given that the thermal conductivity and diffusivity of silicon is 2 orders of magnitude higher than Pyrex®. This paper demonstrates how to fabricate all-silicon micro-columns that can withstand the temperature cycling required for temperature-programmed separations. The columns were sealed using a novel bonding process where they were first bonded using a gold eutectic bond, then annealed at 1100 °C to allow gold diffusion into silicon and form what we call a gold diffusion eutectic bond. The gold diffusion eutectic-bonded micro-columns when examined using scanning electron microscopy (SEM), scanning acoustic microscopy (SAM) and blade insertion techniques showed bonding strength comparable to the previously reported anodic-bonded columns. Gas chromatography-based methane injections were also used as a novel way to investigate proper sealing between channels. A unique methane elution peak at various carrier gas inlet pressures demonstrated the suitability of gold diffusion eutectic-bonded channels as micro-GC columns. The application of gold diffusion eutectic-bonded all-silicon micro-columns to temperature-programmed separations (120 °C min−1) was demonstrated with the near-baseline separation of n-C6 to n-C12 alkanes in 35 s.

Quantification of cancellous bone-compaction due to DHS ® Blade insertion and influence upon cut-out resistance

Background Compaction of cancellous bone is believed to prevent cut-out. This in vitro study quantified the compaction in the femoral head due to insertion of a dynamic hip screw-blade with and without predrilling and investigated the resulting implant anchorage under cyclic loading. Methods Eight pairs of human cadaveric femoral heads were instrumented with a dynamic hip screw-blade made of Polyetheretherketon. Pairwise instrumentation was performed either with or without predrilling the specimens. CT scanning was performed before and after implantation, to measure bone-compaction. Subsequently the implant was removed and a third scan was performed to analyze the relaxation of the bone structure. Commercial implants were reinserted and the specimens were cyclically loaded until onset of cut-out occurred. The bone-implant interface was monitored by means of fluoroscopic imaging throughout the experiment. Paired t-tests were performed to identify differences regarding compaction, relaxation and cycles to failure. Findings Bone density in the surrounding of the implant increased about 30% for the non-predrilled and 20% for the predrilled group when inserting the implant. After implant removal the predrilled specimens fully relaxed; the non-predrilled group showed about 10% plastic deformation. No differences were found regarding cycles to failure ( P = 0.32). Interpretation Significant bone-compaction due to blade insertion was verified. Even though compaction was lower when predrilling the specimens, mainly elastic deformation was present, which is believed to primarily enhance the implant anchorage. Cyclic loading tests confirmed this thesis. The importance of the implantation technique with regard to predrilling is therefore decreased.

Cricoid pressure: should we lay off the pressure?

We read with great interest the editorial by Calder and Yentis questioning what is in essence ‘safe practice’ [1]. We feel this could also bring into question the use of cricoid pressure. Although being described as far back as the 18th century it was Sellick who reintroduced it in 1961 as a means of preventing aspiration during the induction of anaesthesia [2]. Despite the introduction of cricoid pressure, aspiration still occurs and there is little evidence that it has improved patient outcome [2, 3]. In Sellick’s description of its correct application, patients were in a tonsillectomy position with their head and neck fully extended thus increasing the anterior convexity of the cervical spine, stretching the oesophagus and preventing its lateral displacement [4]. CT and MRI studies on non anaesthetised volunteers have shown that in up to 50% of the subjects the oesophagus was viewed lateral to the cricoid ring and that cricoid pressure displaced it more laterally [5, 6]. This questions the view that in its current day practise, direct pressure on the cricoid ring, fully compresses the oesophagus. It is often performed ineffectively and may cause a degree of airway obstruction. Even when performed correctly, it may interfere with laryngeal mask airway insertion, laryngoscopy and success in intubation [7]. This interference with routine airway manoeuvres and therefore the potential failure to optimally manage the airway is often the cause of the morbidity and mortality rather than any aspiration itself [2]. It is not unusual for the anaesthetist to ask for the pressure to be eased off to improve laryngoscopic view, negating the so-called benefits of cricoid pressure. Is there a reasonable alternative? A 1959 study by Snow and Nun in which 606 high risk cases were induced with a 40° head up tilt (reverse Trendelenburg) without any cricoid pressure applied revealed only one case of regurgitation which was attributed to the under dosing of the muscle relaxant. The 40° head up tilt raises the larynx approximately 19 cm higher than the lower oesophageal sphincter, preventing passive reflux into the pharynx. The significance of this height was based on observations by O’Mullane who found that even with distension of the abdomen, the intragastric pressure did not rise above 18 cmH2O unless there was contraction of the abdominal wall [8]. Similarly, there were no cases of aspiration when using a similar approach for inducing 600 obstetric patients with a head up tilt [9]. There are some other benefits of this position. Compared to lying supine, the functional residual capacity and oxygen reservoir may be greater after preoxygenation. In more obese patients, it is easier to ventilate patient in head up tilt as there is less of an effect on lung compliance in this position. The effect of gravity on pregnant patients and those with large breast causes less obstruction to the blade insertion during laryngoscopy compared to lying supine. This is also a well recognised approach to the intubating morbidly obese. Perhaps there is some merit to this technique which was superseded by cricoid pressure back in the 1960s. Is it time we turned back the clock?

Cannot ventilate, difficult to intubate

Editor: A 57-yr-old (90 kg) male was scheduled to undergo a left orbit osseointegration procedure for attachment of a facial prosthesis. He had previously undergone a craniofacial resection for squamous cell carcinoma of the left ethmoid sinus with exenteration of the left orbit followed by a course of radiotherapy. The pre-anaesthetic evaluation of this patient was unremarkable apart from some limitation of mouth opening. He had a grommet insertion under general anaesthesia 3 months before but no records were available. Since his previous surgeries were apparently uneventful, it was decided to anaesthetize this patient using total intravenous anaesthesia with muscle relaxant. Because of the anticipated duration of surgery (>3 h) endotracheal intubation was planned. The patient was routinely asked to give consent for the use of his photographs for teaching and research purposes as well as for publications. In the theatre after monitoring was instituted, the patient was pre-oxygenated, given 3 mg of midazolam as a premedicant and target-controlled infusions of propofol and remifentanil infusions were commenced. It became apparent that we were unable to ventilate this patient with a face mask because of the facial defect and the removal of the orbital floor. A size-5 laryngeal mask was inserted through which ventilation was easy. Atracurium 45 mg was then given. On direct laryngoscopy we could not visualize the epiglottis. Attempts with a McCoy blade and blind bougie insertion also failed, although oxygenation and ventilation with the laryngeal mask was well maintained when reinserted. The patient's airway was secured by asleep fibre-optic nasal intubation with a 7.0 reinforced tracheal tube that was clearly visible through the orbital defect (Fig. 1). The surgery proceeded smoothly and the patient was extubated uneventfully.Figure 1.: Tracheal tube seen through the open orbit.Discussion Anaesthetists may find it difficult or impossible to face-mask ventilate such patients where the orbital floor has been removed. Endotracheal intubation may also be difficult because of altered anatomy as a result of previous surgery and the effects of radiotherapy. Awake trans-orbital intubation, fibre-optic trans-orbital intubation [1,2], the use of lighted stylets and tracheotomy have all been reported in the airway management of similar cases, especially in patients with scarring of the face and limited mouth opening. However, in our case a trans-orbital tube would have made the surgery difficult. In this case, awake fibre-optic intubation would have been the safest method of airway management.

Recovery of Blade-Insertion-Tested Si Wafer Pairs by Thermal Healing

A new method of thermal healing treatment to study the recovery of the bonding energy of a previously opened bonded surface between oxidized silicon wafers was presented in this report. The wafers, partially deboned by blade insertion, were subjected to various annealing temperatures for thermal healing purposes. The annealed wafer pairs were re-examined by a second cycle of blade-insertion testing. During each cycle of blade insertion, the length of the propagated crack due to the inserting blade was continuously monitored by using an infrared light and a charge-coupled device camera. Comparing the crack lengths in front of the inserted blades from those IR transmission images, the healing quality of the annealed wafers is observed. It is found that a healing treatment provides good bonding quality.

Simulation of Boiling Water Reactor One-Pump Trip Transient by TRAC/BF1-ENTRÉE

The three-dimensional plant simulator TRAC/BF1-ENTRÉE was validated based on a one-pump trip test. Trends in major plant process parameters and three-dimensional power distributions were studied with regard to in-core flow reduction, insertion of control blades, and neutron spectrum mismatch. An improved moderator direct heating model was proposed by separately modeling the neutron slowing down and the gamma-ray absorption mechanism. The delayed heat conduction caused by the gamma heating in metallic regions was implemented. Sensitivities of water level and three-dimensional power were studied by varying the core power history, the dryer loss coefficient, and the neutron kinetics solution approach.

Improved Low-Temperature Si ­ Si Hydrophilic Wafer Bonding

Low-temperature processing is important for bond and exfoliation and materials integration techniques. Of particular importance for hydrophilic wafer bonding is the reduction and removal of thermally generated voids at the bond interface, i.e., voids not caused by particulates. Possible causes of thermally generated voids are excess water and hydrocarbon contamination, both at the bond interface. Several bonding preparation techniques were explored, and the effects on interfacial void density and bond strength were recorded. After bonding, all wafer pairs were annealed to 250°C. Infrared imaging was used to monitor void formation, and bond strength was measured using the blade insertion method. Microvoids with lateral dimensions greater than 30 μm were imaged using acoustic microscopy. The highest bond strength was 1260 for plasma-cleaned wafers followed closely by 1150 for an HF oxide strip before hydrophilization. In addition to these techniques, bonding in a vacuum or the use of a prebond anneal were able to eliminate interfacial voids up to the anneal temperature. © 2003 The Electrochemical Society. All rights reserved.

Metodologia para avaliação de impacto ambiental de macrófitas em mesocosmos

Este trabalho teve como objetivo analisar a metodologia para avaliação do impacto ambiental causado pelo uso de herbicidas no controle de macrófitas. O desenho e a construção dos mesocosmos são descritos em detalhes, como também a forma como foram inseridos lâminas para coleta e medida da comunidade perifítica e sedimento para avaliação da comunidade bentônica. O método utilizado foi o de fluxo contínuo, e vários parâmetros de qualidade de água foram medidos, além da determinação de resíduos na coluna d'água e no sedimento. A intenção de se utilizar um método de fluxo contínuo foi buscar uma situação mais próxima da realidade, a fim de que os resultados obtidos possam espelhar com maior exatidão os possíveis riscos provenientes do uso de substâncias químicas no controle das macrófitas. Alguns ajustes devem ser feitos nessa metodologia para melhor caracterização dos efluentes e calibração do sistema.

Pin Power Reconstruction Methods of the Few-Group BWR Core Simulator NEREUS

An improved pin power reconstruction method has been incorporated in the few-group nodal BWR core simulator NEREUS, which is based on the analytic polynomial nodal method. With the analytic polynomial nodal method, accurate node surface fluxes are available, which are used later to reconstruct pin powers. The intranodal homogeneous thermal flux is corrected using a semi-empirical proportional relation between surface transition components of the homogeneous and heterogeneous fluxes. This correction method is effective for BWR calculations, especially for controlled assemblies or mixed loading of off-set assemblies. A unified model accounting for effects of spectral histories, caused by spectral interactions between fuel assemblies and the control blade insertion, was also developed for intranodal burnup correction. The change in pin powers due to the control blade history can be predicted well, without laborious assembly depletion calculations with control blade insertion. R-factors used in critical power ratio calculations are also reconstructed from the pin powers. The NEREUS pin power reconstruction method was verified against heterogeneous multi-assembly depletion calculations.

Advanced Nodal Methods of the Few-Group BWR Core Simulator NEREUS

A few-group nodal BWR core simulator NEREUS, which is based on the analytic polynomial nodal method, has been developed. The analytic polynomial nodal method is applicable to multigroups and has good accuracy for analysis of cores having large spectral mismatch between fuel assemblies, since the intranodal thermal flux can be correctly represented. In NEREUS, the following advanced methods are adopted to overcome the shortcomings of the conventional analytic polynomial nodal method. The flux solution iteration matrix is cast into the form of finite difference, by using the flux discontinuity factors which correct the finite difference error as well as the homogenization error. The intranodal burnup and spectral history distributions are considered in the method, and source moments are obtained by orthogonal expansions. Burnup calculations are made by looking-up exposure dependent tables for macroscopic cross sections, which are prepared by single assembly spectrum and depletion calculations. A unified model accounting for effects of spectral histories, caused by the spectral interaction between fuel assemblies and the control blade insertion, was incorporated. The NEREUS code was verified against benchmark problems and core tracking calculations.

Advanced Nodal Methods of the Few-Group BWR Core Simulator NEREUS.

A few-group nodal BWR core simulator NEREUS, which is based on the analytic polynomial nodal method, has been developed. The analytic polynomial nodal method is applicable to multigroups and has good accuracy for analysis of cores having large spectral mismatch between fuel assemblies, since the intranodal thermal flux can be correctly represented. In NEREUS, the following advanced methods are adopted to overcome the shortcomings of the conventional analytic polynomial nodal method. The flux solution iteration matrix is cast into the form of finite difference, by using the flux discontinuity factors which correct the finite difference error as well as the homogenization error. The intranodal burnup and spectral history distributions are considered in the method, and source moments are obtained by orthogonal expansions. Burnup calculations are made by looking-up exposure dependent tables for macroscopic cross sections, which are prepared by single assembly spectrum and depletion calculations. A unified model accounting for effects of spectral histories, caused by the spectral interaction between fuel assemblies and the control blade insertion, was incorporated. The NEREUS code was verified against benchmark problems and core tracking calculations.

Cervical spine motion with direct laryngoscopy and orotracheal intubation. An in vivo cinefluoroscopic study of subjects without cervical abnormality.

Cervical spine kinetics during airway manipulation are poorly understood. This study was undertaken to quantify the extent and distribution of segmental cervical motion produced by direct laryngoscopy and orotracheal intubation in human subjects without cervical abnormality. Ten patients without clinical or radiographic evidence of cervical spine abnormality underwent laryngoscopy using a #3 Macintosh blade while under general anesthesia and neuromuscular blockade. Cervical motion was recorded with continuous lateral fluoroscopy. The intubation sequence was divided into distinct stages and the corresponding fluoroscopic images were digitized. Segmental motion, occiput through C5, was calculated for each stage using the digitized data. During exposure and laryngoscope blade insertion, minimal displacement of the skull base and rostral cervical vertebral bodies was observed. Visualization of the larynx created superior rotation of the occiput and C1 in the sagittal plane, and mild inferior rotation of C3-C5. C2 maintained nearneutral posture. This pattern of displacement resulted in extension at each motion segment, with the most significant motion produced at the occipitoatlantal and atlantoaxial joints (mean = 6.8 degrees and 4.7 degrees, respectively). Intubation created slight additional superior rotation at the occiput and C1, without substantial alteration in the posture of C2-C5. After laryngoscope removal, position trended toward baseline at all levels, although exact neutral posture was not regained. This investigation quantifies the behavior of the normal cervical spine during direct laryngoscopy with a Macintosh blade. With this maneuver, the vast majority of cervical motion is produced at the occipitoatlantal and atlantoaxial joints. The subaxial cervical segments (C2-C5) are displaced only minimally. This study establishes a highly reliable and reproducible method for analyzing cervical motion in real time.

Uniform Tissue Sections Cut with a Double-Bladed Scalpel

A double-bladed scalpel for cutting tissue sections of uniform thickness is described. A scalpel handle was modified to permit the insertion of adjacent parallel blades separated by a 3 mm gap. This instrument enhances the ability to cut tissue sections of a constant thickness before the samples are submitted for embedding. (The J Histotechnol 16:363, 1993)

Endoscopic carpal tunnel release: A cadaveric study

Endoscopic carpal tunnel release was performed on 13 fresh-frozen cadavers using the Agee 3-M "Inside Job" Endoscopic Carpal Tunnel Release System, by a surgeon specifically trained in the technique and with a large clinical experience. Independent dissections showed no inadvertent lacerations to nerves, vessels, or tendons. The superficial palmar arch, the communicating branch between the ulnar and median nerves at the palm, and the common digital nerves to the third and fourth web spaces were the structures most at risk. Measurements of the distances between external landmarks were not helpful in accurately predicting the depth of blade insertion. In five of 13 cases there was complete release of the transverse carpal ligament. In four of the remaining eight cases fine fibers of the transverse carpal ligament or fascia connecting the thenar and hypothenar muscles were left over. In the other four cases there was an incomplete release of the transverse carpal ligament. The palmar fascia and more volar structures were preserved in the majority of cases.

An analysis of laryngoscope blade shape and design: new criteria for laryngoscope evaluation.

Laryngoscope blade design has tended to be relatively arbitrary and so far scientific analysis has not allowed useful comparisons between blade shapes. A new theoretical method of analysing laryngoscope blades is introduced and uses the depth of insertion profiles of two angular measurements. One represents eyeline displacement and the other the forward space that the blade occupies at the level of the mandible. Photographs of straight and curved blades were studied on Cartesian graphs with the tip T, at the origin and handle fittings parallel to the x-axis of the graph. Then, IT is any line from the origin to the incisor surface and represents a point of contact with the upper incisors for a given depth of blade insertion. Angle EIT (eyeline displacement) is to a tangent from I along the lower lingual surface of the blade. Point M is on the upper lingual surface of the blade, at right angles to IT, 1/3 of the distance from I along IT. Angle MIT (forward space) may be positive or negative depending on whether M is in front of or behind IT. The angles EIT, MIT and their additive combination are used in blade analysis. Negative MIT compensates for eyeline displacement as Macintosh size 3 and 4 blades have better combination scores than Miller size 3. All three are superior to the straight Soper size 3 blade. The Macintosh size 1 and 2 blades are quite different from the larger Macintosh blades. This theoretical basis for blade analysis is consistent with commonly expressed clinical opinions and may influence blade design in the future.

The Treatment of Status Epilepticus

Status epilepticus, though declining in frequency in recent years, is a medical emergency as well as a persistently difficult problem in balanced therapy. By its very nature it is likely to require the direct involvement of the family physician be he a pediatrician or a general practitioner. It may be useful to begin by defining and considering special aspects in relation to causes and age. Most convulsive seizures are self-limiting events terminating on their own accord before specific medical treatment need or can be rendered. For these, positioning to prevent aspiration of excessive secretions and vomitus and prevention of self-injuries is generally sufficient. Prying open clenched teeth for the insertion of time-honored tongue blades, pencils, or fingers has no place in modern medicine. These maneuvers are useless in the prevention of tongue biting (that will have occurred at the onset of the initial tonic phase), but may actually be harmful by dislodging loose teeth, and by initiating nociceptive stimuli that reflexly can prolong the tonic phase. Likewise excessive restraining of convulsing patients may faciitate bone injuries. The administration of drugs postictally is unnecessary in the majority of isolated seizures. Exceptions of course are prolonged or serial convulsions, or status epilepticus as discussed below, and those instances in which the convulsion has occurred because of failure in taking prescribed antiepileptic medication. The recent availability for quick appraisal of serum levels of antiepileptic drugs is a useful guide in this respect. Turning now to the definition of status epilepticus: official formulations such as "an attack which is so prolonged or so frequently repeated as to constitute a definite lasting condition" is open to some confusion.

An oral surgeon's experience with the intraosseous blade implant

Experience with the endosseous blade implant is evaluated from the point of view of the oral surgeon. General considerations, including anatomic, prosthetic, and periodontic are covered, as are complications and sequelae of this modality. The technique of endosseous blade insertion is described.