Manual In-Line Stabilization of the Cervical Spine Increases the Rate of Difficult Oro-Tracheal Intubation in Adults - A Randomized Controlled Trial

Background: Patients with traumatic brain injury present with loss of consciousness andsuspected cervical fracture. The aim of this study was to determine the rate of difficult orotracheal intubation in surgical patients undergoing various procedures when manual in-line neck immobilization technique was applied. Methods: This was a randomized prospective study at the Lagos University Teaching Hospital. A total of 100 patients were enrolled into the study and were allocated into 2 groups of either Manual In-Line Stabilization (MILS) or Early Morning Sniffing position (EMSP) techniques during intubation. Successful or unsuccessful intubations within 30secs, as well as time to successful intubation were the outcome measures. Results: The mean ± SD intubation time for successful intubation was similar in both groups (MILS=17.9±7.7 seconds, EMSP=14.6±6.6 seconds (p=0.359)).There were more failed intubations in the MILS group (27%) and (2%) in the EMSP group (p=0.001). Conclusion: The study showed that patients who had MILS had more failed intubations than those that were intubated with the EMSP technique. With this level of failed intubations there is need for provision of difficult airway laryngoscopic adjuncts for patients with diagnosed cervical fracture and uncleared cervical injury who require orotracheal intubation.Key Words: Manual inline stabilization, Cervical spine injury, Orotracheal intubation, Difficult intubatio

Observation of inductively coupled-plasma-induced damage on n-type GaN using deep-level transient spectroscopy

The effects of inductively coupled plasma (ICP) etching on electrical properties of n-type GaN Schottky contacts were investigated by observing ion damage using deep-level transient spectroscopy. An electron trap, not previously seen, localized near the contact, as well as a pre-existing trap, was observed in the ICP-etched sample. The ICP-etched surface was found to be N-deficient, which means that N vacancies (V-N) were produced by ICP etching. From these, the origin of the ICP-induced electron trap was suggested to be V-N or a V-N-related complex of point defects. The ICP-induced traps provided a path for the transport of electrons, leading to the reduction of Schottky barrier height and increase of gate leakage current.open273

Prevalence and Antibiotic Susceptibility Pattern of Staphylococcus Aureus in Clinical Specimens

The present study was carried out to determine the prevalence of Staphylococcus aureus in clinical samples and their susceptibility pattern to antibiotics. Standard microbiological and biochemical methods were used to screen 155 clinical specimens comprising of sputum, wound, urine and high vaginal swabs for S .aureus. Twenty eight (28) isolates was obtained from these samples. Antibiotic susceptibility results shows high percentage of sensitivity to gentamicin (89%,) azithromycin (89%), pefloxacin (79%)  followed by erythromycin (68%) ciprofloxacin (61%) streptomycin (61%)and sparfloxacin (54%). A high resistance was recorded for cotrimaxazole (90%), amoxycillin (88%), ampicillin (73%), tetracycline (65%), cefuroxime and cephalexin (40%) each. Key words: Staphylococcus aureus, antibiotic susceptibility, prevalence, resistance

Temperature-dependence of a GaN-based HEMT monolithic X-band low noise amplifier

The temperature-dependent performance of a fully monolithic AlGaN/GaN HEMT-based X-band low noise amplifier is reported. The circuit demonstrated a noise figure of 3.5 dB, gain of 7.5 dB, input return loss of -7.5 dB, and output return loss of -15 dB at 8.5 GHz at room temperature. The noise figure at 9.5 GHz increased from 2.5 dB at 43°C to 5.0 dB at 150°C. © 2004 IEEE

AlGaN/GaN HEMT-based fully monolithic X-band low noise amplifier

A fully monolithic AlGaN/GaN HEMT-based low noise amplifier is reported. The circuit demonstrated a noise figure of 3.5 dB, gain of -7.5 dB, input return loss of -7.5 dB, and output return loss of -15 dB at 8.5 GHz. The dc characteristics of individual 0.25-μm × 150-μm transistors were: maximum current density of 1.0 A/mm, maximum transconductance of 170 mS/mm and a threshold voltage of -6.8 V. The devices have a typical short circuit current gain cutoff frequency of 24.5 GHz and a maximum oscillating frequency of 48 GHz. The devices demonstrated a minimum noise figure of 1.6 dB with an associated gain of 10.6 dB at 10 GHz. © 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Plasma-etching-enhanced deep centers in n-GaN grown by metalorganic chemical-vapor deposition

By using deep-level transient spectroscopy (DLTS), deep centers have been characterized in unintentionally doped n-GaN samples grown by metalorganic chemical-vapor deposition and subjected to inductively coupled plasma reactive ion etching. At least six DLTS traps exist in the control sample: A1 (∼0.90 eV), Ax (∼0.72 eV), B (0.61 eV), C1 (0.44 eV), D (0.25 eV), and E1 (0.17 eV), with B dominant. Then, as the etching bias-voltage increases from −50 to −150 V, trap D increases strongly and becomes dominant, while traps A1, C (0.34 eV), and E1 increase at a slower rate. Trap B, on the other hand, is nearly unchanged. Previous electron-irradiation studies are consistent with the E1 traps being N-vacancy related. It is likely that the D traps are also, except that they are in the regions of dislocations

Differential cartilaginous tissue formation by human synovial membrane, fat pad, meniscus cells and articular chondrocytes

Objective: To identify an appropriate cell source for the generation of meniscus substitutes, among those which would be available by arthroscopy of injured knee joints. Methods: Human inner meniscus cells, fat pad cells (FPC), synovial membrane cells (SMC) and articular chondrocytes (AC) were expanded with or without specific growth factors (Transforming growth factor-betal, Fibroblast growth factor-2 and Plate let-derived growth factor bb, TFP) and then induced to form three-dimensional cartilaginous tissues in pellet cultures, or using a hyaluronan-based scaffold (Hyaff(R)-11), in culture or in nude mice. Human native menisci were assessed as reference. Results: Cell expansion with TFP enhanced glycosaminoglycan (GAG) deposition by all cell types (up to 4.1-fold) and messenger RNA expression of collagen type II by FPC and SMC (up to 472-fold) following pellet culture. In all models, tissues generated by AC contained the highest fractions of GAG (up to 1.9 were positively stained for collagen type II (specific of the inner avascular region of meniscus), type IV (mainly present in the outer vascularized region of meniscus) and types I, III and VI (common to both meniscus regions). Instead, inner meniscus, FPC and SMC developed tissues containing negligible GAG and no detectable collagen type II protein. Tissues generated by AC remained biochemically and phenotypically stable upon ectopic implantation. Conclusions: Under our experimental conditions, only AC generated tissues containing relevant amounts of GAG and with cell phenotypes compatible with those of the inner and outer meniscus regions. Instead, the other investigated cell sources formed tissues resembling only the outer region of meniscus. It remains to be determined whether grafts based on AC will have the ability to reach the complex structural and functional organization typical of meniscus tissue. (C) 2006 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights rese

Oxygen Tension Is a Determinant of the Matrix-Forming Phenotype of Cultured Human Meniscal Fibrochondrocytes

BACKGROUND: Meniscal cartilage displays a poor repair capacity, especially when injury is located in the avascular region of the tissue. Cell-based tissue engineering strategies to generate functional meniscus substitutes is a promising approach to treat meniscus injuries. Meniscus fibrochondrocytes (MFC) can be used in this approach. However, MFC are unable to retain their phenotype when expanded in culture. In this study, we explored the effect of oxygen tension on MFC expansion and on their matrix-forming phenotype. METHODOLOGY/PRINCIPAL FINDINGS: MFC were isolated from human menisci followed by basic fibroblast growth factor (FGF-2) mediated cell expansion in monolayer culture under normoxia (21%O(2)) or hypoxia (3%O(2)). Normoxia and hypoxia expanded MFC were seeded on to a collagen scaffold. The MFC seeded scaffolds (constructs) were cultured in a serum free chondrogenic medium for 3 weeks under normoxia and hypoxia. Constructs containing normoxia-expanded MFC were subsequently cultured under normoxia while those formed from hypoxia-expanded MFC were subsequently cultured under hypoxia. After 3 weeks of in vitro culture, the constructs were assessed biochemically, histologically and for gene expression via real-time reverse transcription-PCR assays. The results showed that constructs under normoxia produced a matrix with enhanced mRNA ratio (3.5-fold higher; p<0.001) of collagen type II to I. This was confirmed by enhanced deposition of collagen II using immuno-histochemistry. Furthermore, the constructs under hypoxia produced a matrix with higher mRNA ratio of aggrecan to versican (3.5-fold, p<0.05). However, both constructs had the same capacity to produce a glycosaminoglycan (GAG) -specific extracellular matrix. CONCLUSIONS: Our data provide evidence that oxygen tension is a key player in determining the matrix phenotype of cultured MFC. These findings suggest that the use of normal and low oxygen tension during MFC expansion and subsequent neo-tissue formation cultures may be important in engineering different regions of the meniscus