The influence of spinal flexion in the lateral decubitus position on the unilaterality of spinal anesthesia

BACKGROUND

For unilateral spinal block, local anesthetics should affect the spinal nerves of 1 side. With full flexion of the spine, the sunken cauda equina becomes tightened and is suspended in the middle of the subarachnoid space. We performed this study to assess whether spinal flexion facilitates unilateral spinal anesthesia.

METHODS

Hyperbaric bupivacaine (8 mg) was administered at the L3-4 interspace through a 25-gauge Quincke needle at a rate of 0.02 mL/s. Patients were randomly allocated to group F (with full spinal flexion) or group N (the hips and back straightened). After maintaining the lateral position for 15 minutes with or without spinal flexion, patients were gently returned to the supine position. Spinal blockade was assessed by loss of pinprick sensation and the modified Bromage motor scale.

RESULTS

While the lateral position was maintained, sensory block was noted on the nondependent side in 14 of 16 patients in group N (87.5%) but only in 1 of 16 patients in group F (6.3%) (P < 0.001). The median level of sensory block in group N was L5 on the nondependent side just before turning to the supine position. When patients were returned to the supine position, sensory blockade on the nondependent side was noted in all group N patients (100%) and 15 group F patients (93.7%). The sensory level on the nondependent side between group N and group F were similar after turning supine.

CONCLUSIONS

Strict unilateral sensory block was not achieved even after lateral decubitus positioning with spinal flexion, when 8 mg hyperbaric bupivacaine was administered manually at a conventionally slow rate through a beveled spinal needle. However, maintaining flexion of the spinal column during lateral decubitus positioning altered the initial onset of sensory block with respect to laterality.

Comparison of the efficacy of ramosetron and ondansetron in the prophylaxis of postoperative vomiting in children receiving fentanyl by patient-controlled analgesia after orthopedic surgery: a randomized controlled trial

BACKGROUND

This study was designed to compare the efficacy of prophylactic ramosetron and ondansetron in preventing postoperative vomiting in children who received fentanyl by patient-controlled analgesia after orthopedic surgery.

METHODS

Two hundred and eighteen children, 2-15 years old, ASA physical status 1 or 2, scheduled for elective orthopedic surgeries, were randomly divided into the ramosetron group (n = 109) or ondansetron group (n = 109). Patients in ondansetron group received ondansetron 100 μg·kg(-1) and patients in ramosetron group received ramosetron 6 μg·kg(-1) after surgery. Intravenous patient-controlled analgesia with fentanyl was used in both groups. The incidence of postoperative vomiting and side effects were assessed during the 48 h after surgery.

RESULTS

There was significantly less vomiting during the first 24-h and 6-24-h period after surgery in ramosetron group than in ondansetron group (P < 0.01). There were no significant differences in side effect of 5-HT(3) antagonist between the two groups.

CONCLUSION

Ramosetron was more effective during the first 24-h period after surgery than ondansetron in children using fentanyl patient-controlled analgesia after general anesthesia.

The effects of an insulin-glucose-potassium (IGK) pretreatment on the bupivacaine cardiotoxicity

BACKGROUND

The purpose of this study is to evaluate the effect of an IGK pretreatment on the cardiotoxicity of bupivacaine.

METHODS

Twenty-one anesthetized mongrel dogs were randomly divided into the following three groups: the control group (CG, n = 7), the treatment group (TG, n = 7) and the pretreatment group (PTG, n = 7). For the 30 min of pretreatment period, CG and TG received normal saline, while PTG received an IV bolus of insulin 2 U/kg, followed by an IGK infusion (2 U/kg/hr of insulin, 0.5-1.5 g/kg/hr of glucose, 1-2 mEq/kg/hr of KCl). The bupivacaine infusion was started at the rate of 0.5 mg/kg/min in all groups after the pretreatment period. CG received normal saline only. In TG, insulin (2 U/kg) was injected simultaneously with bupivacaine infusion, followed by the IGK infusion as with PTG. The hemodynamic variables and the time duration to reach the mean arterial pressure (MAP) of 60 mmHg were compared.

RESULTS

The bupivacaine infusion decreased the cardiac index, MAP, and heart rate in all three groups. Although insulin concentration was higher in TG than in PTG during bupivacaine infusion, the hemodynamic variables in PTG decreased at the slowest rate. The time taken to reach MAP of 60 mmHg in PTG, TG, and CG was 51.4 ± 8.5, 36.4 ± 9.6, and 27.1 ± 8.7 min, respectively (P < 0.05).

CONCLUSIONS

IGK delays the bupivacaine-induced cardiac depression. However, a pretreatment with IGK is more effective in delaying the bupivacaine-induced hypotension than simultaneous administration, regardless of insulin concentration.

Method of synthesized phase objects for pattern recognition: matched filtering

To solve the pattern recognition problem, a method of synthesized phase objects is suggested. The essence of the suggested method is that synthesized phase objects are used instead of real amplitude objects. The former is object-dependent phase distributions calculated using the iterative Fourier-transform (IFT) algorithm. The method is experimentally studied with a Vander Lugt optical-digital 4F-correlator. We present the comparative analysis of recognition results using conventional and proposed methods, estimate the sensitivity of the latter to distortions of the structure of objects, and determine the applicability limits. It is demonstrated that the proposed method allows one: (а) to simplify the procedure of choice of recognition signs (criteria); (b) to obtain one-type δ-like recognition signals irrespective of the type of objects; (с) to improve signal-to-noise ratio (SNR) for correlation signals by 20 - 30 dB on average. The spatial separation of the Fourier-spectra of objects and optical noises of the correlator by means of the superposition of the phase grating on recognition objects at the recording of holographic filters and at the matched filtering has additionally improved SNR (>10 dB) for correlation signals. To introduce recognition objects in the correlator, we use a SLM LC-R 2500 device. Matched filters are recorded on a self-developing photopolymer.

Spectroscopic investigation of the A and 3 1Σ+ states of 39K85Rb

By using a combination of molecular beam (MB) excitation spectra and two distinct ultracold molecule excitation spectra (UM+ and UM-), we have assigned high vibrational levels of the A and 3 (1)Σ(+) states from absorption spectra of the mutually strongly perturbed A (1)Σ(+) - 3 (1)Σ(+) - 1 (1)Π - 2 (3)Σ(+) - b (3)Π states of ultracold (39)K(85)Rb molecules in the energy region between 15,116 and 16,225 cm(-1) above the minimum of the ground X (1)Σ(+) state. The ultracold molecules (UM+ and UM-) are formed by radiative decay following photoassociation (PA) to a specific level of the 3(0(+)) state (UM+) or to a specific level of the 3(0(-)) state (UM-). We observe that the A and 3 (1)Σ(+) states are observable in the UM+ spectra, but absent from the UM- spectra. This is explained by considering Hund's case (c) selection rules and transition dipole moments between the upper excited A (1)Σ(+) (2(0(+))) state and the three Ω components (0(+), 0(-), and 1) at the ground-state dissociation limit. We propose further investigations of the extended potential wells of the A and 3 (1)Σ(+) states by combining short-range MB excitation spectra in a narrow Franck-Condon (FC) window near R(e) of the X (1)Σ(+) state, and long-range UM (and PA) excitation spectra, which have much larger FC windows.

DoGeNetS: using optimisation to discriminate regulatory network topologies based on gene expression data

Gene regulatory networks (GRNs) determine the dynamics of gene expression. Interest often focuses on the topological structure of a GRN while numerical parameters (e.g. decay rates) are unknown and less important. For larger GRNs, inference of structure from gene expression data is prohibitively difficult. Models are often proposed based on integrative interpretation of multiple sources of information. We have developed DoGeNetS (Discrimination of Gene Network Structures), a method to directly assess candidate models of GRN structure against a target gene expression data set. The transsys language serves to model GRN structures. Numeric parameters are optimised to approximate the target data. Multiple restarts of optimisation yield score sets that provide a basis to statistically discriminate candidate models according to their potential to explain the target data. We demonstrate discrimination power of the DoGeNetS method by relating structural divergence to divergence between gene expression data sets. Known models are used to generate target expression data, and a set of candidate models with a defined structural divergence to the true model is produced. Structural divergence and divergence of expression profiles after optimisation are strongly correlated. We further show that discrimination is possible at noise levels exceeding those typical of contemporary microarray data. DoGeNetS is capable of discriminating the best GRN structure from among a small number of candidates. p values indicate whether differences in divergence of expression are significant. Although this study uses single gene knockouts, the DoGeNetS method can be adapted to simulate a virtually unlimited range of experimental conditions. [Includes supplementary material].

Classification of Cryptococcus neoformans and yeast-like fungus isolates from pigeon droppings by colony phenotyping and ITS genotyping and their seasonal variations in Korea

Cryptococcus neoformans (C neoformans) is a frequent cause of invasive fungal disease in immunocompromised human hosts. Ninety-eight samples of pigeon droppings were collected from the pigeon shelters in Seoul, and cultured on birdseed agar (BSA) and Sabouraud dextrose agar (SDA). One hundred yeast-like colonies were selected and identified via phenotype characteristics, such as colony morphology and biochemical characteristics. This was then followed with genotyping via sequencing of the internal transcribed spacer (ITS) region. The colonies were classified into four kinds of colony color types: brown type (BrT), beige type (BeT), pink type (PT), and white type (WT). Numbers of isolated BrT, BeT, PT, and WT colonies were 22 (22%), 30 (30%), 19 (19%), and 39 (39%), respectively. All BrT colonies were identified as C neoformans. BeT were identified as 19 isolates of Cryptococcus laurentii, 10 isolates of Malassezia furfur, and 1 isolate of Cryptococcus uniguttulatus. PT was divided into two colony color types: light-PT (l-PT) and deep-PT (d-PT). Eighteen of l-PT and one of d-PT were identified as Rhodotorula glutinis and Rhodotorula mucilaginosa, respectively. WT were identified as 34 isolates of Cryptococcus guilliermondii, 3 isolates of Cryptococcus zeylanoides, 1 isolate of Cryptococcus sake, and 1 isolate of Stephanoascus ciferrii. Most strains were classified identically with the use of either phenotype or genotyping techniques, but C uniguttulatus and C sake classified by phenotyping were Pseudozyma aphidis and Cryptococcus famata by genotyping. This rapid screening technique of pathogenic yeast-like fungi by only colony characteristics is also expected to be very useful for primary yeast screening. Additionally, we investigated the seasonal variations of C neoformans and other yeast-like fungi from 379 pigeon-dropping samples that were collected from February 2011 to March 2011. We isolated 685 yeast-like fungi from the samples. Almost all C neoformans and yeast-like fungi were isolated in the fall (298 strains, 43.5%) and spring (244 strains, 35.6%). A few yeast-like fungi were isolated in winter (98 strains, 14.3%) and summer (45 strains, 6%). These results would be used as an important indicator related to epidemiology and prevention of pathogenic yeast-like fungi infections transmitted through pigeon droppings.

The influence of DNA polymorphism of multidrug resistant 1 (MDR1) on the effect of midazolam pretreatment in children

Background

Patients showed a different response following intravenous midazolam injection. Some children showed irritability or were not sedated by midazolam. We hypothesized that there may be genetic variations of the MDR1 gene, based on the response to midazolam.

Methods

One hundred and ninety-three pediatric patients were recruited in this study. Midazolam (0.1 mg/kg) was injected intravenously before surgery. Anxiety score (activity, vocalizations, emotional expressivity, state of apparent arousal) was checked before and 5 minutes after midazolam injection. In addition, other manifestations after midazolam injection were recorded. After anesthesia, 2 ml of blood was sampled. Children were genotyped MDR1. Haplotype was analyzed using the software package PHASE, version 2.0.

Results

The observed frequencies of MDR1 haplotype of TTT, TGC, CAC, CGC were 0.334, 0.205, 0.182 and 0.225, respectively. There was no significant correlation between the response of midazolam and the MDR1 haplotype of TTT, TGC, CAC or CGC (P = 0.98).

Conclusions

Genotyping of MDR1 may not be related to the response of midazolam in children.

Robust and multifunctional nanosheath for chemical and biological nanodevices

The contribution of advanced nanoscale chemical and biological devices to life science has been limited to a small number of nanomaterials, due to the absence of effective surface modification routes. Herein, we demonstrate a polymer-like nanosheath synthesized by nonthermal plasma technology (NPT) that can protect the core nanomaterial from the solution environment and provide a multifunctional platform for chemical and biological nanosensors. For ZnO nanowires (NWs) which are unstable in solution, we demonstrate that this nanosheath makes it possible for ZnO NW field-effect transistors to act as a pH sensor for 24 h and a biosensor for the real-time, label-free detection of liver cancer markers.

Application of the continuous autotransfusion system (CATS) to prevent transfusion-related hyperkalemia following hyperkalemic cardiac arrest in an infant -A case report-

Transfusion-induced hyperkalemia can lead to cardiac arrest, especially when the patient rapidly receives a large amount of red blood cells (RBCs), previously stored for a long period of time, irradiated or both. We report on a case of application of the Continuous AutoTransfusion System (CATS) to wash RBCs, in order to lower the high potassium (K(+)) level in the packed RBCs unit, during massive transfusion following transfusion-induced hyperkalemic cardiac arrest. After the washing process using CATS, there was no more electrocardiographic abnormality or cardiac arrest due to hyperkalemia. This case emphasizes the potential risk to develop transfusion-related hyperkalemic cardiac arrest, during massive transfusion of irradiated, pre-stored RBCs. CATS can be effectively used to lower the K(+) concentration in the packed RBCs unit, especially when the risk of transfusion-induced hyperkalemia is high.

Spectroscopic analysis of the coupled 1(1)Π, 2(3)Σ+ (Ω = 0-, 1), and b(3)Π (Ω = 0±, 1, 2) states of the KRb molecule using both ultracold molecules and molecular beam experiments

We report the spectroscopic characterization of excited electronic states of KRb by combining spectra from molecular beam (MB) experiments with those from ultracold molecules (UM) formed by photoassociation (PA) of ultracold atoms. Spectra involving the 1(1)Π, 2(3)Σ(+), and b(3)Π states in a strongly perturbed region have been identified. This approach provides a powerful method to identify the vibrational levels of the excited electronic states perturbed globally by neighboring electronic states. This is because the two sets of spectra from the UM and the MB experiments probe the same energy region from very different initial electronic states. The UM experiments utilize high v'' levels of the a(3)Σ(+) state with large internuclear separations, while the MB experiments utilize low v'' levels of the ground X(1)Σ(+) state with near-equilibrium internuclear separations. Only the Ω = 1 levels of the 2(3)Σ(+) and b(3)Π states are observed in the MB spectra, while the Ω = 0(-), 1 levels of the 2(3)Σ(+) state and the Ω = 0(±), 1, 2 levels of the b(3)Π state are observed in the UM spectra.

Modal loss mechanism of micro-structured VCSELs studied using full vector FDTD method

Modal properties of vertical cavity surface-emitting lasers (VCSELs) with holey structures are studied using a finite difference time domain (FDTD) method. We investigate loss behavior with respect to the variation of structural parameters, and explain the loss mechanism of VCSELs. We also propose an effective method to estimate the modal loss based on mode profiles obtained using FDTD simulation. Our results could provide an important guideline for optimization of the microstructures of high-power single-mode VCSELs.

Unravelling complex spectra of a simple molecule: REMPI study of the 420 nm band system of KRb

Complex spectra of the KRb 420 nm system are analyzed by mass-resolved resonance enhanced two-photon ionization in a cold molecular beam. Vibronic structures of three singlet-singlet (4(1)Π, 7(1)Σ(+), and 5(1)Π←X(1)Σ(+)) transitions were identified for the first time. By comparing with highly accurate ab initio calculations, we assigned the singlet excited electronic states, and determined their electronic term values and vibrational constants. Weak singlet-triplet transitions were observed and identified as the 5(3)Π(0(+))←X(1)Σ(+) transitions by the homogeneous perturbation selection rule.

Colloid coalescence with focused x rays

We show direct evidence that focused x rays enable us to merge polymer colloidal particles at room temperature. This phenomenon is ascribed to the photochemical scission of colloids with x rays, reducing the molecular weight, glass transition temperature, surface tension, and viscosity of colloids. The observation of the neck bridge growth with time shows that the x-ray-induced colloid coalescence is analogous to viscoelastic coalescence. This finding suggests a feasible protocol of photonic nanofabrication by sintering or welding of polymers, without thermal damage, using x-ray photonics.

The effect of cardioplegic solution-induced sodium concentration fluctuation on postoperative seizure in pediatric cardiac patients

BACKGROUND

Despite potential benefits of histidine-tryptophan-ketoglutarate (HTK) solution as a cardioplegic solution, it can cause hyponatremia, especially in pediatric patients. Fluctuations in the sodium concentration during cardiopulmonary bypass (CPB) can adversely affect the central nervous system. We evaluated the relationship between the cardioplegic solution, the fluctuation of sodium concentration, and the incidence of postoperative seizure in pediatric cardiac patients.

METHODS

The medical records of 628 patients were reviewed for the occurrence of a postoperative seizure, type of cardioplegic solution (HTK or del Nido solution), and intraoperative data. A change of sodium concentration exceeding 15 mmol/L (ΔNa>15) during CPB was defined as a significant fluctuation of sodium concentration.

RESULTS

Postoperative seizures were detected in 18 patients (2.9%). The ΔNa>15 was detected in 63 of 189 patients (33.3%) who received the HTK solution and in 14 of 439 patients (3.2%) who received the del Nido solution (p<0.001). The incidence of ΔNa>15 was strongly associated with postoperative seizure (odds ratio, 6.3; 95% confidence interval, 2.4 to 16.4, p=0.001). After adjusting for potential confounders, the ΔNa>15 remained significantly associated with postoperative seizure (odds ratio, 3.9; 95% confidence interval, 1.3 to 12.3, p=0.018).

CONCLUSIONS

Histidine-tryptophan-ketoglutarate solution during CPB frequently causes fluctuations of sodium concentration, usually combined with hyponatremia, which is associated with postoperative seizure. Special attention to sodium concentration is required, particularly when HTK solution is used in pediatric cardiac patients.

A comparison of GlideScope(®) videolaryngoscopy and direct laryngoscopy for nasotracheal intubation in children

BACKGROUND

The relative effectiveness of GlideScope(®) videolaryngoscopy (GV) for nasotracheal intubation in pediatric patients is unclear. The purpose of this study is to evaluate the usefulness of GV for nasotracheal intubation compared with direct laryngoscopy (DL) in pediatric patients.

METHODS

Our patient cohort consisted of 80 children <10 years of age who required nasotracheal intubation for elective dental or facial surgery. The patients were randomly allocated to GV (n = 40) or DL (n = 40) group. The time to intubation (TTI), glottic view grade, frequency of Magill forceps use, and degree of difficulty in intubation were evaluated.

RESULTS

The median TTI was similar between the groups. The TTI of the former 20 patients was faster in the DL group (53.3 s, interquartile range: 42.0-64.3) than GV group (65.9 s, interquartile range: 56.0-93.9) (P = 0.007), whereas the TTI of the latter 20 patients was comparable between the groups. There were no significant differences in glottic view grade, frequency of Magill forceps use, and degree of difficulty in intubation between the two groups.

CONCLUSIONS

GV can provide similar intubation performance characteristics compared with DL when used for nasotracheal intubation in pediatric patients. However, experience is needed to be skillful in the GV to acquire comparable TTI with DL.

Anesthetic management with scalp nerve block and propofol/remifentanil infusion during awake craniotomy in an adolescent patient -A case report-

Despite of various neurophysiologic monitoring methods under general anesthesia, functional mapping at awake state during brain surgery is helpful for conservation of speech and motor function. But, awake craniotomy in children or adolescents is worrisome considering their emotional friabilities. We present our experience on anesthetic management for awake craniotomy in an adolescent patient. The patient was 16 years old male who would undergo awake craniotomy for removal of brain tumor. Scalp nerve block was done with local anesthetics and we infused propofol and remifentanil with target controlled infusion. The patient endured well and was cooperative before scalp suture, but when surgeon sutured scalp, he complained of pain and was suddenly agitated. We decided change to general anesthesia. Neurosurgeon did full neurologic examinations and there was no neurologic deficit except facial palsy of right side. Facial palsy had improved with time.

Transfusion-free anesthetic management for open heart surgery in a neonate -A case report-

In small infants or neonates, open heart surgery without transfusion can have many risks regarding inadequate oxygen delivery and coagulopathy. However, if parents refuse blood transfusion, cardiac surgery without transfusion should be considered. We report a case of bloodless cardiac surgery in a 2.89 kg neonate with Jehovah's Witness parents. Blood conserving strategies were used. Preoperatively, erythropoietin and iron were supplemented to increase the hemoglobin level. Intraoperatively, techniques for minimizing blood loss were used, such as reducing priming volume for cardiopulmonary bypass, a blood salvage system, and modified ultrafiltration. Postoperatively, pharmacologic agents were administered and blood sampling was minimized.

Accessory polar renal artery encountered in transperitoneal systemic laparoscopic paraaortic lymphadenectomy

OBJECTIVE

To increase vigilance among gynecological surgeons for the presence of accessory polar renal artery (APRA) encountered with transperitoneal systemic laparoscopic paraaortic lymphadenectomy (LPAL).

METHODS

A retrospective review was conducted on 156 women who underwent LPAL for various gynecologic malignancies between November 2003 and December 2009.

RESULTS

The median age, parity, body mass index, and number of previous abdominal surgeries, respectively, of the women were 52 years (range, 23-82 years), two (range, 0-7), 24.1 kg/m2 (range, 17.4-35.0 kg/m2), and 0 (range, 0-3). During the study period, we found four women with APRA. There were three cases of right lower APRAs arising from the abdominal aorta, caudal to the inferior mesenteric artery (IMA), terminating at the parenchyma of the lower pole of the right kidney. In the other case, the APRA arose from the abdominal aorta superior to the IMA. There were no vascular complications, such as transection or ligation of the APRA.

CONCLUSION

It is important for the gynecological oncologic surgeon to have knowledge of retroperitoneal vascular anatomy, experience in laparoscopic surgery, and an accurate surgical technique to avoid vascular injury during LPAL.

Ultralow bending loss fibers with higher-order mode strippers

We propose and demonstrate bend-insensitive fibers equipped with higher-order mode strippers. The mode stripper is realized by filling a section of air holes with epoxy to attenuate any higher-order modes that are excited at fiber junctions and are confined by the air holes surrounding the core. We found that the higher-order modes are well suppressed with 5 cm-long epoxy columns. An ultralow bending loss of 0.025 dB/turn at a bend diameter of 10 mm, together with single-modeness, is experimentally demonstrated in a bend-insensitive fiber with six air holes 16 μm in diameter.

Cardiac arrest induced by tension pneumothorax during ventilating bronchoscopy -A case report-

Tension pneumothorax during ventilating bronchoscopy for foreign body removal is a rare but life-threatening complication. The authors present a case of cardiac arrest caused by tension pneumothorax in a 9-month-old girl who underwent ventilating bronchoscopy for foreign body (peanut) removal. Tension pneumothorax was due to tracheobronchial lacerations caused by a bronchoscope. The patient was successfully resuscitated by cardiopulmonary resuscitation and chest tube insertion. The airway injury was effectively repaired by thoracotomy under extracorporeal membrane oxygenation.

Anesthetic management of video-assisted thoracoscopic surgery (VATS) in pediatric patients: the issue of safety in infant and younger children

Background

The purpose of this study was to assess the safety issues concerning anesthetic management of video-assisted thoracoscopic surgery (VATS) in pediatric patients.

Methods

The medical records of 52 pediatric patients undergoing VATS using general anesthesia and one-lung ventilation (OLV) were reviewed. OLV was achieved with a Fogarty catheter (n = 23) or endobronchial intubation (n = 7) in patients < 10 years of age (group Y, n = 30), and using a double-lumen tube (n = 19) or a univent (n = 3) in children aged between 10 and 16 years of age (group O, n = 22). Hypoxemia, hypercarbia, the difference between E_TCO₂ and PaCO₂, and the effect of CO₂ insufflation were assessed.

Results

A decrease in SpO₂ less than 90% was observed in 40% of the group Y, compared to none of the group O (P < 0.05). A hypercarbia (E_TCO₂ > 50 mmHg) was observed more frequently in group Y (40%) than in group O (0%; P < 0.05). The difference between the E_TCO₂ and PaCO₂ was 10.4 ± 8.9 mmHg in group Y and 4.6 ± 3.9 mmHg in group O (P < 0.05). Hypercarbia and acidosis occurred more frequently in patients with CO₂ insufflation than those without insufflation in group Y.

Conclusions

Although the anesthesia for VATS in pediatric patients was successfully accomplished, the infants and younger children presented with more intra-operative problems when compared with older children. The anesthetic management for VATS in infants and younger children requires careful and vigilant monitoring.

The 480 nm system of KRb: 1 3Delta1, 4 1Sigma+, and 5 1Sigma+ states

We have investigated the KRb 480 nm system by mass-resolved resonance enhanced two-photon ionization in a cold molecular beam. The 1 (3)Delta(1), 4 (1)Sigma(+), and 5 (1)Sigma(+) <-- X (1)Sigma(+) transitions have been identified. For the 1 (3)Delta(1) and 5 (1)Sigma(+) states, the electronic term values and vibrational constants are determined experimentally for the first time. Potential energy curves of the 4 (1)Sigma(+) and 5 (1)Sigma(+) states undergo multiple avoided crossings with nearby (1)Sigma(+) states in the observed spectral region. For the 4 (1)Sigma(+) state, a vibrational numbering of the experimentally observed levels is suggested. Anomalies in vibronic structures of the 4 (1)Sigma(+) and 5 (1)Sigma(+) states are understood by comparison with high-level ab initio calculations currently available. The avoided crossing energies are also experimentally estimated.

Submitral left ventricular aneurysm of ischemic origin: report of two surgical cases

Submitral left ventricular aneurysm has been exclusively recognized in the young African population and its occurrence in other than black Africans is rarely reported. Here we describe two surgical cases of submitral left ventricular aneurysm in Asian elderly persons. Although the aneurysms were typically located beneath the posterior mitral valve leaflet, we could identify diseased coronary arteries as well, unlike the reports in the literature asserting that this type of aneurysm occurs in the absence of coronary disease. The possible racial difference with regard to the etiology is addressed.

CPAP of 10 cmH2O during cardiopulmonary bypass followed by an alveolar recruitment manoeuvre does not improve post-bypass oxygenation compared to a recruitment manoeuvre alone in children

This randomised controlled study assessed whether continuous positive airway pressure (CPAP) of 10 cmH2O during cardiopulmonary bypass improves post-bypass oxygenation in children compared with no CPAP during bypass. We studied children with a ventricular septal defect. CPAP of 10 cmH2O was applied during bypass in the CPAP group (n=24), whereas the lungs were left deflated in the control group (n=20). In both groups, an alveolar recruitment maneuver was performed by applying positive pressure of 30 to 40 cmH2O for five seconds before weaning from bypass. Postoperative ventilation had the peak inflation pressure set to produce an expired tidal volume of 8 ml/kg with positive end expiratory pressure of 5 cmH2O. Arterial blood gas and haemodynamic measurements were performed at skin incision, five minutes after weaning from bypass, five minutes after chest closure and four hours after arrival in the intensive care unit. In four children CPAP was discontinued because it adversely affected the operating field. There was no difference in demographic characteristics, haemodynamic data, bypass time and operation time. No difference was observed between the groups with respect to pH, PaO2, P(A-a) DO2, PaCO2, and ETCO2 at each time. Variability in the data was greater than expected, leading to a decrease in the expected power of the study. CPAP at 10 cmH2O during bypass was not found to improve the post-bypass oxygenation as compared with leaving the lung deflated during bypass in children undergoing ventricular septal defect repair who had an alveolar recruitment maneuver at the end of bypass.

The effect of grain boundaries inside the individual ZnO nanowires in gas sensing

We present the gas sensing characteristics of the individual ZnO nanowires with single-crystalline and multiple grain boundaries (GBs) fabricated using bottom-up and top-down approaches, respectively. The sensor response of the individual ZnO nanowires with the multiple GBs was enhanced approximately three times as compared to that of single-crystalline ZnO nanowires due to well-known GB modulations. However, the response and recovery times of the individual ZnO nanowires with multiple GBs were much slower than those of the single-crystalline ZnO nanowire, indicating the presence of oxygen diffusion resistance to GBs due to the relatively fast surface kinetic reaction. Simplified kinetic diffusion modeling and experimental results could quantify the significant diffusion resistance of gas molecules into the GBs of the individual ZnO nanowires.

The synthesis of single PdAu bimetallic nanowire: feasibility study for hydrogen sensing

Single PdAu bimetallic nanowires have been synthesized via the sequential processes of electrochemical deposition and dielectrophoresis (DEP). In the first step, Pd/Au grains on predefined Au electrodes were grown by electrochemical deposition and could assist effectively the formation of a single PdAu nanowire with a good directionality by the subsequent DEP process. The synthesized PdAu nanowires have an average of approximately 10 at.% of Pd, a good resistance of a few hundred Omega, diameters of 300 nm on average and lengths of up to 15 microm. Based on the single PdAu nanowire, hydrogen detection was demonstrated in the range from 100 to 2500 ppm.

Practical anatomic landmarks for determining the insertion depth of central venous catheter in paediatric patients

BACKGROUND

Various methods have been recommended to decide a proper insertion depth of central venous catheter (CVC). The carina is recommended as a useful target level for the CVC tip position. We evaluated the sternal head of a right clavicle and the nipples as anatomic landmarks for determining the optimal depth of CVC in paediatric patients.

METHODS

Ninety children, <5 yr, undergoing catheterization through the right internal jugular vein were enrolled. The insertion depth was determined as follows. The insertion point was designated as 'Point I'. The sternal head of the right clavicle was called 'Point A' and the midpoint of the perpendicular line drawn from Point A to the line connecting both nipples was called 'Point B'. The insertion depth of CVC was determined by adding the two distances (from I to A and from A to B) and subtracting 0.5 cm from this. A chest radiography was taken and the distance of the CVC tip from the carina level was measured by the Picture Archiving and Communicating System.

RESULTS

The mean distance of the CVC tip from the carina level was 0.1 (1.0) (P=0.293) cm above the carina (95% CI 0.1 cm below the carina-0.3 cm above the carina). There was no specific relationship between the distance of the CVC tip from the carina level and the patients' age, height, and weight.

CONCLUSIONS

The CVC tip could be placed near the carina by using the external landmarks without any formulae, images, and devices in children in our study.