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The Casimir effect, which predicts the emergence of an attractive force between two parallel, highly reflecting plates in vacuum, plays a vital role in various fields of physics, from quantum field theory and cosmology to nanophotonics and condensed matter physics. Nevertheless, Casimir forces still lack an intuitive explanation and current derivations rely on regularisation procedures to remove infinities. Starting from special relativity and treating space and time coordinates equivalently, this paper overcomes no-go theorems of quantum electrodynamics and obtains a local relativistic quantum description of the electromagnetic field in free space. When extended to cavities, our approach can be used to calculate Casimir forces directly in position space without the introduction of cut-off frequencies., 8 pages, 2 figures

This paper revisits the life of Adolf Lindenbaum in light of new research findings, then looks at two areas among many—metric spaces, and decompositions of point sets—where his work has been underappreciated.

To describe the successful perioperative hemostatic management of a Jehovah's Witness patient with hemophilia B and anaphylactic inhibitors to factor IX, undergoing scoliosis surgery.A 14 (1/2)-yr-old boy with severe hemophilia B who had a history of anaphylactic inhibitors to factor IX was scheduled to undergo corrective scoliosis surgery. He was initially started on epoetin alfa and iron supplementation to maximize preoperative red cell mass. Additionally, he was placed on a desensitization protocol of recombinant coagulation factor IX (rFIX) and was then treated with activated recombinant coagulation factor VII (rFVIIa) during the postoperative period. Tranexamic acid was given concomitantly. The intraoperative blood loss was approximately 350 mL. The nadir hemoglobin concentration was 111 g.L(-1) on postoperative days one and two. On postoperative day 11, the patient was stable and discharged home with a hemoglobin of 138 g.L(-1). He did not require blood transfusion and no adverse events were observed.The use of rFIX, rFVIIa, erythropoetin, iron, and tranexamic acid before, during and after scoliosis surgery may be a viable and safe option for hemophilia patients with inhibitors, who refuse blood products.

Nanoelectrospray ionization (nanoESI) mass spectrometry was performed on naturally occurring steroid sulfates and unconjugated steroids derivatized to their sulfate esters using precursor ion monitoring. Initially, an extraction method was developed based on a combinatorial approach employed to obtain the most efficient liquid/liquid extraction protocol. The new method allowed unconjugated steroids and their sulfated analogues to be isolated separately in a two-step procedure using diethyl ether/hexane (90:10, v/v) in the first step to extract the unconjugated steroids and chloroform/2-butanol (50:50, v/v) in the second step to extract steroid sulfates. Precursor ion scanning performed with a triple-quadrupole mass spectrometer was used to examine quantitatively the extracted unconjugated and sulfated steroids, where the recovery efficiency averaged 70 and 87%, respectively. In addition, some steroids could be structurally elucidated by employing tandem mass spectrometry. The limit of detection for steroid sulfates from the biological matrix was 200 amol/microL (approximately 80 fg/microL) with only 1 microL of sample being injected. Endogenous levels of the unconjugated and sulfated steroids were detected and quantified from physiological samples including urine and blood. Internal standards, pregnenolone-d4 sulfate and dehydroepiandrosterone-d2 (DHEA), were used for quantitation. Extraction and nanoESI analyses were also performed on cerebrospinal fluid where the neurosteroid DHEA sulfate was detected. The small amount of material consumed (typically less than 20% of the injection volume) suggests that nanoESI has even greater potential for high sensitivity when combined with nanoLC approaches, especially for monitoring reproductive and adrenal steroids, as well as for the analysis of the less abundant neurosteroids.

Craniopagus conjoined twins have long been the subject of interest because of the rarity and peculiarity of their juxtaposition. We present the surgical, airway and anesthetic challenges in craniopagus conjoined twins, in which one of the twins underwent adenoidectomy for obstructive sleep breathing disorder. The surgical procedure required a special setting from an anesthetic perspective whereby both children needed anesthesia due to the complex physiology of their brains and cardiovascular systems. As well, we took the opportunity to do bilateral ear examinations of both twins.

Morphine is avoided by many neurosurgeons following cranial surgery. There exists a concern regarding the potential complications and a perception that cranial surgery is less painful than other surgical procedures. At British Columbia Children's Hospital continuous morphine infusions (CMI) have been used to control pain in pediatric neurosurgical patients. The purpose of this study was to compare the safety and efficacy of continuous intravenous morphine infusion to standard oral analgesics in a neurosurgical ward setting.A retrospective review of medical records for 71 children was completed. The patients underwent either cranial reconstruction (2002-2007) or craniotomies for intradural pathology (2005-2007) at British Columbia Children's Hospital. Outcome measures included pain control and adverse events. Comparison was made between patients receiving a CMI and patients receiving acetaminophen and codeine.Thirty-seven children received CMI on the ward (30 cranial reconstruction and 7 craniotomy), while 34 (10 cranial reconstruction and 24 craniotomy) received acetaminophen and codeine. There was no statistical difference in pain control. There was significantly more nausea on post-operative day one in the CMI group (p = 0.002). There were no other significant adverse events.These findings suggest that CMI is comparable to acetaminophen and codeine with respect to analgesia and serious side effects. We recommend the use of CMIs as an alternative when pain is poorly controlled in post-operative pediatric neurosurgical patients to prevent the potential adverse consequences of inadequate analgesia.

Background and Purpose — It has been proposed that the novel spin trap agent disodium-[(tert-butylimino)methyl]benzene-1,3-disulfonate N -oxide (NXY-059) may be useful in the treatment of ischemia and stroke. To date, there is little information concerning the safety of NXY-059 when administered in combination with the only Food and Drug Administration–approved pharmacological agent for the treatment of stroke, the thrombolytic tissue plasminogen activator (tPA). Thus, we determined the effects of NXY-059G, a generic form of NXY-059, on hemorrhage and infarct rate and volume when administered alone or in combination with tPA. In addition, we determined whether NXY-059G affected 2 physiological variables, blood glucose levels and body temperature. Methods — Male New Zealand White rabbits were embolized by injecting a large blood clot into the middle cerebral artery via a catheter. Five minutes after embolization, NXY-059G (100 mg/kg) was infused intravenously; control rabbits received infusions of saline, the vehicle required to solubilize NXY-059G. In tPA studies, the thrombolytic was administered intravenously starting 60 minutes after embolization (20% bolus injection/80% infusion over 30 minutes). Body temperature and blood glucose levels were measured throughout the study. Postmortem analysis included assessment of hemorrhage and infarct rate, size, and location. Results — In the vehicle control group, the hemorrhage rate after a thromboembolic stroke was 52% (n=23), and this was increased by 67% if tPA was administered (n=15). The rabbits treated with NXY-059G in the absence of tPA had a 79% incidence of hemorrhage (n=19), an increase of 52% over the control group. In the combination drug–treated groups, the NXY-059G/tPA group had a 47% incidence of hemorrhage (n=15). There was a decrease of hemorrhage volume in the NXY-059G+tPA group compared with the other 3 groups included in the study. There was no significant effect of NXY-059G either alone or in combination with tPA on infarct rate or volume. NXY-059G did not significantly alter the physiological variables that were measured. Conclusions — This study suggests that NXY-059G may affect the integrity of the cerebral vasculature when administered immediately after an embolic stroke, as evidenced by an increase in hemorrhage rate. However, when NXY-059G is administered in combination with tPA, it may improve the safety of tPA by reducing the incidence of tPA-induced hemorrhage. The mechanism(s) involved in the NXY-059G–induced increase in hemorrhage rate and reduction of tPA-induced hemorrhage rate remains to be elucidated.

Background Rapacuronium is a rapid-onset, short-acting neuromuscular relaxant. This multiple-center study determined neuromuscular recovery when neostigmine was given 2 or 5 min after rapacuronium. Methods One hundred seventeen patients were randomized to receive two different doses of rapacuronium and to receive neostigmine in two different doses and at two different times. During propofol anesthesia with nitrous oxide, oxygen, and fentanyl, 1.5 or 2.5 mg/kg rapacuronium was given 1 min before tracheal intubation. Neuromuscular block was measured by train-of-four ulnar nerve stimulation every 12 s: The adductor pollicis force of contraction was recorded mechanomyographically. Two or five minutes after rapacuronium was administered, 0.05 or 0.07 mg/kg neostigmine was administered and recovery was compared with that of control patients who received no neostigmine. Results Both doses of rapacuronium produced 100% block in all but one patient, who exhibited 97% block. Neostigmine accelerated recovery in all groups. After 1.5 mg/kg rapacuronium, the time to 25% T1 twitch recovery decreased from a mean of 16 min in control patients to mean values of 8-10 min in the treatment groups: The time to train-of-four ratio of 0.7 decreased from 38 min to 17-19 min. After 2.5 mg/kg rapacuronium, the time to 25% T1 was reduced from 23 min to 11-12 min, and the time to train-of-four ratio of 0.7 decreased from 54 min to 26-32 min. Recovery was not different among the the groups that received different doses and timing of neostigmine. Conclusions Recovery of intense rapacuronium block was accelerated by early neostigmine administration. When given 2 min after rapacuronium, neostigmine was as effective as after 5 min, and 0.05 mg/kg neostigmine was comparable to 0.07 mg/kg neostigmine.

To determine, retrospectively, the age of packed red blood cell (PRBC) units transfused to patients admitted to the ICU with the diagnosis of severe sepsis and to correlate this vanable with outcome. All patients admitted to the ICU during 1992 with a diagnosis of severe sepsis were selected retrospectively. The criteria for the diagnosis of severe sepsis and septic shock were based on established guidelines. For each patient the total number of PRBC units transfused, the number of units transfused before, during and after the septic episode, and the age of each PRBC unit transfused were recorded. Of the 31 patients admitted to the ICU with severe sepsis, 19 died and 12 survived. No statistical differences between survivors and nonsurvivors were found with respect to age, sex, number of days in ICU, duration of sepsis, incidence of septic shock, admission Apache Il score or total number of PRBC units transfused. During sepsis the median age of PRBC units transfused to survivors was 17 days (range 5–35)vs 25 days (range 9–36) for nonsurvivors (P < 0.0001). A negative correlation (r = −0.73) was found between the proportion of PRBC units of a given age transfused to survivors and increasing age of PRBC. This is the first study to report a correlation of mortality with the age of PRBC transfused. The cause of this association is unclear. If this association is confirmed by a prospective randomised tnal it would have major implications for the use of PRBC in severe sepsis.

The experiment described in this report deals with the binding of mercury(II) by human serum albumin.