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While carbon provides the basis for all of organic chemistry and biology, elemental carbon compounds themselves play vital roles in our world. Graphite, diamond, fullerenes, graphene, and amorphous carbon solids are used in myriad modern applications, and a number of new, metastable states of carbon with unusual and promising properties have recently been proposed and created. Furthermore, liquid carbon and warm dense carbon are of astrophysical interest, and been proposed to exist in the cores of large planets and stars (Ross, 1981) [1]. While much is known about the solid forms of carbon, its liquid state remains very poorly understood. Due to difficulties in preparing and studying this material, its structure and properties remain essentially unknown. In this review, we describe recent technological advances which have enabled new experiments on liquid carbon samples, prepared with laser melting and shock compression techniques.

We have examined the transmission of soft X-ray pulses from the FERMI free electron laser through carbon films of varying thickness, quantifying nonlinear effects of pulses above and below the carbon K-edge. At typical of soft X-ray free electron laser intensities, pulses exhibit linear absorption at photon energies above and below the K-edge, ∼308 and ∼260 eV, respectively; whereas two-photon absorption becomes significant slightly below the K-edge, ∼284.2 eV. The measured two-photon absorption cross section at 284.18 eV (∼6 × 10−48 cm4 s) is 7 orders of magnitude above what is expected from a simple theory based on hydrogen-like atoms - a result of resonance effects.

Nonlinear optical processes at soft x-ray wavelengths have remained largely unexplored due to the lack of available light sources with the requisite intensity and coherence. Here we report the observation of soft x-ray second harmonic generation near the carbon K edge (∼284  eV) in graphite thin films generated by high intensity, coherent soft x-ray pulses at the FERMI free electron laser. Our experimental results and accompanying first-principles theoretical analysis highlight the effect of resonant enhancement above the carbon K edge and show the technique to be interfacially sensitive in a centrosymmetric sample with second harmonic intensity arising primarily from the first atomic layer at the open surface. This technique and the associated theoretical framework demonstrate the ability to selectively probe interfaces, including those that are buried, with elemental specificity, providing a new tool for a range of scientific problems.

The existence of liquid carbon as an intermediate phase preceding the formation of novel carbon materials has been a point of contention for several decades. Experimental observation of such a liquid state requires nonthermal melting of solid carbon materials at various laser fluences and pulse properties. Reflectivity experiments performed in the mid-1980s reached opposing conclusions regarding the metallic or insulating properties of the purported liquid state. Time-resolved X-ray absorption studies showed shortening of C-C bonds and increasing diffraction densities, thought to evidence a liquid or glassy carbon state, respectively. Nevertheless, none of these experiments provided information on the electronic structure of the proposed liquid state. Herein, we report the results of time-resolved resonant inelastic X-ray scattering (RIXS) and time-resolved X-ray emission spectroscopy (XES) studies on amorphous carbon (a-C) and ultrananocrystalline diamond (UNCD) as a function of delay time between the irradiating pulse and X-ray probe. For both a-C and UNCD, we attribute decreases in RIXS or XES signals to transition blocking, relaxation, and finally, ablation. Increased signal at 20 ps following the irradiation of the UNCD is attributed to the probable formation of nanoscale structures in the ablation plume. Differences in the amount of signal observed between a-C and UNCD are explained by the difference in sample thickness and, specifically, incomplete melting of the UNCD film. Comparisons to spectral simulations based on MD trajectories at extreme conditions indicate that the carbon state in our experiments is crystalline. Normal mode analysis confirmed that symmetrical bending or stretching of the C-C bonds in the diamond lattice results in XES spectra with small intensity differences. Overall, we observed no evidence of melting to a liquid state, as determined by the lack of changes in the spectral properties for up to 100 ps delays following the melting pulses.

FlyFactorSurvey (http://pgfe.umassmed.edu/TFDBS/) is a database of DNA binding specificities for Drosophila transcription factors (TFs) primarily determined using the bacterial one-hybrid system. The database provides community access to over 400 recognition motifs and position weight matrices for over 200 TFs, including many unpublished motifs. Search tools and flat file downloads are provided to retrieve binding site information (as sequences, matrices and sequence logos) for individual TFs, groups of TFs or for all TFs with characterized binding specificities. Linked analysis tools allow users to identify motifs within our database that share similarity to a query matrix or to view the distribution of occurrences of an individual motif throughout the Drosophila genome. Together, this database and its associated tools provide computational and experimental biologists with resources to predict interactions between Drosophila TFs and target cis-regulatory sequences.

Background: The effects of a muscle relaxant may differ in elderly compared with young adult patients for a variety of reasons. The authors compared the effects of a new muscle relaxant (cisatracurium) in young and elderly adults and used pharmacokinetic/pharmacodynamic modeling to identify factors explaining differences in time course of effect., Methods: Thirty-one young (18-50 yr) and 33 elderly ( > 65 yr) patients anesthetized with nitrous oxide, isoflurane, and fetanyl were studied. Cisatracurium (0.1 mg/kg) was given after induction of anesthesia and later additional boluses of 0.025 mg/kg or an infusion of cisatracurium was given. Neuromuscular transmission was measured using the first twitch of the train-of-four response at the adductor pollicis after supramaximal stimulation of the ulnar nerve at 2 Hz every 15 s. Five venous blood samples were obtained for plasma drug concentration at intervals ranging from 2 to 120 min from every patient. Three additional samples were obtained from those who received an infusion. A population pharmacokinetic/pharmacodynamic model was fitted to the plasma concentration and effect data. The parameters of the model were permitted to vary with age to identify where differences existed between young and elderly adults., Results: Onset of block was delayed in the elderly; values being mean 3.0 (95% confidence interval 1.75-11.4) min and 4.0 (2.4-6.5) min in the young and elderly, respectively (P < 0.01). Duration of action was similar in the two groups. Plasma clearance was 319 (293-345) ml/min in the study population and did not differ between young and elderly patients. Apparent volume of distribution was 13.28 (9.9-16.7) 1 and 9.6 (7.6-11.7) 1 in the elderly and young adults, respectively (P < 0.05). There also were differences in pharmacodynamic parameters between the young and elderly; the predominant change being a slower rate of biophase equilibration (ke0) in the elderly (0.060 [0.052-0.068])/min compared with the young (0.071 [0.065-0.077]/min; P < 0.05)., Conclusions: The pharmacokinetics of cisatracurium differ only marginally between young and elderly adults. Onset is delayed in the elderly because of slower biophase equilibration.

The effects of age on the pharmacokinetics of pancuronium were investigated. The distribution volume of pancuronium did not appear to be age-dependent, but elimination of the drug decreased with increasing age. The clinical implications of these findings are discussed.

Alfentanil 700 micrograms and fentanyl 100 micrograms were compared as anaesthetic adjuvants in 90 patients undergoing short duration gynaecological procedures. The results show that, at the chosen dose ratio, alfentanil causes a higher frequency of post-induction apnoea, but thereafter the respiratory effects of the two drugs were comparable. No differences in incremental requirements or evoked movements were found. Among patients who had been given ergometrine, the alfentanil group suffered a greater frequency of nausea and vomiting in the period immediately after operation. It is concluded that in single i.v. doses, alfentanil 700 micrograms is more potent than fentanyl 100 micrograms. Moreover, the results suggest that, unlike fentanyl, this very short acting agent would be used to greater effect if given in divided doses during surgery.

Tissue transplantation immunity with a specific memory component is demonstrated in populations of Montipora. This highly discriminating immunoreactivity derives from extensive allogeneic polymorphism of histocompatibility (H) markers. An H system of immunorecognition is postulated to have originated in multicellular invertebrates probably beginning with coelenterates.

Unless patients harbouring this uncommon tumour are correctly prepared and protected from the effects of excessive catecholamine release, they are greatly at risk when undergoing surgical procedures of any kind. This short review describes the clinical syndromes associated with phaeochromocytoma, the diagnostic procedures which may identify and localize the tumour(s), the principles and practical aspects of pharmacological control, and a method of anaesthetic management which has proved safe and effective in many patients.

The pharmacokinetics of fentanyl and alfentanil were compared by the simultaneous i.v. administration of both drugs, measurement of plasma concentrations and compartmental analysis. In addition, plasma protein binding, erythrocyte:plasma partition, and heptane:water partition were compared. Alfentanil was found to have a very much smaller apparent volume of distribution, smaller total clearance, and shorter terminal half-time in plasma. Alfentanil was also found to have a greater plasma protein binding, but in contrast to fentanyl, no binding to erythrocytes. It is concluded that alfentanil is less cumulative than fentanyl, has restricted hepatic clearance, and will exhibit non-linear kinetics at very high doses. An appendix describes the model-fitting procedure in detail.

It has been demonstrated that a simple two-compartment kinetic model may account for the changes in plasma concentration of pancuronium after i.v. administration. However, it can be shown that this simple model does not account satisfactory for the observed changes in muscle twitch response. By the addition of a receptor (biophase) compartment, twitch response can be reconciled with model behavior and the characteristics resemble those predicted by animal studies. The complete model is applied to the problem of total renal failure, and shows that patients with this condition are likely to be marginally resistant to small doses of pancuronium, with a normal rate of recovery. However, larger doses are likely to result in delayed recovery, the duration of effect increasing in a dose-dependent manner.

Alfentanil 35 micrograms kg-1, was used successfully in a patient with severe aortic stenosis, in order to minimize the haemodynamic responses to intubation and surgery during Caesarean section. The baby was delivered apnoeic, unresponsive and with poor muscle tone, but responded rapidly to naloxone. Plasma alfentanil concentrations and percentage binding to plasma proteins were measured in both maternal and neonatal blood. Free drug concentrations were similar in both mother and neonate, but maternal plasma proteins had a higher affinity for alfentanil. Only 67.26% of neonatal plasma alfentanil was bound to plasma protein. This value did not differ significantly from those estimated from the blood of a further 12 healthy neonates.

Propofol was used to induce and maintain anaesthesia in patients undergoing minor gynaecological procedures. Quality of anaesthesia, the rate of recovery and the influence of different methods of premedication were assessed. Unpremedicated patients required a higher induction dose than those premedicated with either lorazepam or papaveretum and hyoscine, but maintenance dose requirements were comparable. Regardless of premedication, there were similar decreases in mean arterial pressure, although respiratory function recovered more rapidly in patients premedicated with lorazepam. No significant changes in heart rate were noted in any group. The overall incidence of pain on injection was 3.7% (lignocaine 0.5 mg added to each 9.5 mg of propofol) and a skin rash occurred in 6% of patients. All patients recovered rapidly and uneventfully.

The effect of fentanyl on increases in heart rate and mean arterial pressure elicited by electric stimulation of a branch of the radial nerve was studied in anesthetized, paralyzed, and artificially ventilated dogs. In one group, a bolus of 100 micrograms/kg of fentanyl depressed the evoked changes in heart rate and arterial pressure by 82 and 75%, respectively, by 5 min, and recovery occurred within 90 min. A second group was given increasing bolus doses of fentanyl from 1.5 to 100 micrograms/kg every 20 min for 200 min. The doses and intervals were chosen to give a logarithmic increase in plasma concentration of fentanyl to include a final bolus dose of 100 micrograms/kg and were predicted by a two-compartment pharmacokinetic model derived from data of the first group. In the second group, the bolus dose of 100 micrograms/kg after 5 min had no significant effect on evoked cardiovascular responses. Over the following 2 h, the evoked changes in heart rate and arterial pressure increased above those preceding the 100 micrograms/kg dose. An additional bolus dose of 100 micrograms/kg given 2 h after the first did not depress the evoked reflexes below the control values. It was concluded that tolerance to the effects of fentanyl can occur within 3 h and that for evoked responses to arterial pressure, rebound withdrawal effects can be seen within an additional 90 min.

Antibodies to group A streptococcal carbohydrate, demonstrable by radioimmunoassay, were elicited in Pacific hagfish, Eptatretus stoutii, after prolonged immunization with whole cell vaccine. This hagfish antibody, isolated by ion-exchange chromatography of immune serum, exhibited a single precipitin line after immunoelectrophoresis against rabbit antiserum to hagfish serum. The isolated antibodies retained high binding activity for the streptococcal carbohydrate, but lacked the natural hemagglutinating activity found in both nonimmune and immune sera. Analysis by gel filtration in neutral and dissociating buffers and by sodium dodecyl sulfate/polyacrylamide gel electrophoresis under nonreducing conditions indicated an intact molecule of molecular weight approximately 160,000 that may be noncovalently associated in a polymer of higher molecular weight. Heavy chains of mobility identical to that of murine mu chains and light chains of mobility significantly slower than murine lambda chains were obtained after sodium dodecyl sulfate gel electrophoresis under reducing conditions. Instability of the tertiary structure of the antibody molecule was indicated by partial dissociation in buffers containing sodium dodecyl sulfate and by dissociation at low concentrations of reducing agent. In contrast to its well-developed system of cell-mediated immunity, only a minimal system of circulating antibody production is evident in this primitive fish. No evidence for divergence of cyclostome lymphocytes into separate T- and B-cell systems has yet been discerned.

A demand analgesia apparatus is described. It communicates with the patient by means of spoken messages in any desired language, so that preliminary instruction is unnecessary. Dosage is limited by a reduction in respiratory rate, and by a series of electronic fail-safe circuits. Operation of the system is illustrated in a series of 10 patients given fentanyl "on demand" for the first 12 h after operation. The mean dose rate 0.73 +/- 0.49 microgram min-1. There was no evidence of cumulation or tolerance during the period of study.

In vitro phagocytosis of yeast cells by hemocytes of the mollusc Biomphalaria glabrata can occur in the absence of plasma, but is enhanced by opsonization in plasma from certain snail strains. We have investigated the carbohydrate specificity of the hemocyte-bound receptor for phagocytosis and the free plasma opsonin using two dominant carbohydrate components of the yeast cell wall (laminarin and mannan). Phagocytic uptake in the absence of plasma of both untreated and opsonized yeast is strongly inhibited by laminarin, but is unaffected by mannan. In contrast, laminarin does not interfere with opsonization whereas mannan blocks the process, blocking the binding of a 57 kD plasma component as detected by Western immunoblot. These results suggest that the opsonic lectin in plasma is not simply a free form of the hemocyte-bound receptor for yeast phagocytosis.

After i.v. administration, the distribution and elimination of many drugs may be simulated by a compartmental mathematical model. The analogue can be used to construct such models in electrical terms. When programmed with an appropriate model, the analogue can be used in a wide range of predictive studies. The application of the analogue is illustrated by analysis of serial plasma concentrations of fentanyl and pancuronium.

The neuromuscular blocking characteristics of fazadinium and pancuronium were compared using a general pharmacodynamic model. Since it characterizes the overall relationship between dose and effect, the model can be used to determine precisely equipotent doses, compare time-effect curves, and reconcile the apparently inconsistent clinical and pharmacokinetic characteristics of the two drugs. Fazadinium was shown to have a shorter duration than pancuronium, and appeared to exhibit less variation between subjects. The potency ratio varied between 3.4 : 1 and 7.2 : 1, depending upon the definition chosen. A general solution for the three-compartment open mammillary model, following any set of initial conditions if presented as an appendix. These equations allow explicit computation of any pattern of drug incrementation into any compartment of the model.