We report that defect-free Au nanowires show superplasticity on tensile deformation. Evidences from high-resolution electron microscopes indicated that the plastic deformation proceeds layer-by-layer in an atomically coherent fashion to a long distance. Furthermore, the stress-strain curve provides full interpretation of the deformation. After initial superelastic deformation, the nanowire shows superplastic deformation induced by coherent twin propagation, completely reorientating the crystal from <110> to <100>. Uniquely well-disciplined and long-propagating atomic movements deduced here are ascribed to the superb crystallinity as well as the radial confinement of the Au nanowires.
In vivo 31P MRS demonstrates that human melanoma xenografts in immunosuppressed mice treated with lonidamine (LND, 100 mg/kg, i.p.) exhibit a decrease in intracellular pH (pHi) from 6.90 ± 0.05 to 6.33 ± 0.10 (p < 0.001), a slight decrease in extracellular pH (pHe) from 7.00 ± 0.04 to 6.80 ± 0.07 (p > 0.05), and a monotonic decline in bioenergetics (NTP/Pi) by 66.8 ± 5.7% (p < 0.001) relative to the baseline level. Both bioenergetics and pHi decreases were sustained for at least 3 hr following LND treatment. Liver exhibited a transient intracellular acidification by 0.2 ± 0.1 pH units (p > 0.05) at 20 min post-LND with no significant change in pHe and a small transient decrease in bioenergetics, 32.9 ± 10.6 % (p > 0.05), at 40 min post-LND. No changes in pHi or ATP/Pi were detected in the brain (pHi, bioenergetics; p > 0.1) or skeletal muscle (pHi, pHe, bioenergetics; p > 0.1) for at least 120 min post-LND. Steady-state tumor lactate monitored by 1H MRS with a selective multiquantum pulse sequence with Hadamard localization increased ~3-fold (p = 0.009). Treatment with LND increased systemic melanoma response to melphalan (LPAM; 7.5 mg/kg, i.v.) producing a growth delay of 19.9 ± 2.0 d (tumor doubling time = 6.15 ± 0.31d, log10 cell-kill = 0.975 ± 0.110, cell-kill = 89.4 ± 2.2%) compared to LND alone of 1.1 ± 0.1 d and LPAM alone of 4.0 ± 0.0 d. The study demonstrates that the effects of LND on tumor pHi and bioenergetics may sensitize melanoma to pH-dependent therapeutics such as chemotherapy with alkylating agents or hyperthermia.
BackgroundSpinal anesthesia is the most common regional anesthesia conducted for many surgical procedures. Multiple factors can affect the success, the side effects, and patient satisfaction with the procedure. This study was undertaken prospectively to discover factors affecting dissatisfaction and refusal of spinal anesthesia.MethodsStarting in December 2007, patients who underwent spinal anesthesia in the operating rooms of our hospital were surveyed over a period of a year. Before attempting the procedure, patient characteristics and previous history of anesthesia were recorded. Spinal anesthesia was administered with 0.5% heavy bupivacaine combined with fentanyl 0-20 µg. Intraoperative data and postoperative data on the day after surgery were collected. The patients were also asked about their general satisfaction with spinal anesthesia, causes of dissatisfaction with the procedure, and causes of their refusal to have spinal anesthesia again.ResultsSix patients among 1,197 cases were excluded from the study because of spinal anesthesia failure. The dissatisfaction rate of spinal anesthesia was 3.7%, and its risk factors were more than three puncture attempts, paresthesia at puncture, postoperative nausea and vomiting, and postoperative backache. The refusal rate to have spinal anesthesia again was 3.2%, and its risk factors were postoperative backache and dissatisfaction.ConclusionsAlthough spinal anesthesia was conducted safely during the study and revealed a high rate of patient satisfaction (96.3%), side effects still occurred. Therefore, attending anesthesiologists must perform the procedure carefully and always pay attention to patients under spinal anesthesia.
Propofol or remifentanil anesthesia was associated with a higher incidence of OCR during pediatric strabismus surgery than sevoflurane and desflurane anesthesia, when either ketamine or midazolam was used as an induction agent.
We report magnetism in Cu doped single-crystalline GaN nanowires. The typical diameter and the length of the Ga1-xCuxN nanowires (x = 0.01, 0.024) are 10-100 nm and tens of micrometers, respectively. The saturation magnetic moments are measured to be higher than 0.86 microB/Cu at 300 K, and the Curie temperatures are far above room temperature. Anomalous X-ray scattering and X-ray diffraction measurement make it clear that Cu atoms substitute the Ga sites, and they largely take part in the wurtzite network of host GaN. X-ray absorption and X-ray magnetic circular dichroism spectra at Cu L(2,3) edges show that doped Cu has local magnetic moment and the electronic configuration of it is mainly 3d9 but mixed with a small portion of trivalent component. It seems that the ionocovalent bonding nature of Cu 3d orbital with surrounding semiconductor medium makes Cu atom a mixed electron configuration and local magnetic moments. These outcomes suggest that the Ga1-xCuxN system is a room-temperature ferromagnetic semiconductor.
A network model for the determination of tumor metabolic fluxes from 13 C NMR kinetic isotopomer data has been developed and validated with perfused human DB-1 melanoma cells carrying the BRAF V600E mutation, which promotes oxidative metabolism. The model generated in the bonded cumomer formalism describes key pathways of tumor intermediary metabolism and yields dynamic curves for positional isotopic enrichment and spin-spin multiplets. Cells attached to microcarrier beads were perfused with 26 mM [1,6-13 C 2 ]glucose under normoxic conditions at 37°C and monitored by 13 C NMR spectroscopy. Excellent agreement between model-predicted and experimentally measured values of the rates of oxygen and glucose consumption, lactate production, and glutamate pool size validated the model. ATP production by glycolytic and oxidative metabolism were compared under hyperglycemic normoxic conditions; 51% of the energy came from oxidative phosphorylation and 49% came from glycolysis. Even though the rate of glutamine uptake was ϳ50% of the tricarboxylic acid cycle flux, the rate of ATP production from glutamine was essentially zero (no glutaminolysis). De novo fatty acid production was ϳ6% of the tricarboxylic acid cycle flux. The oxidative pentose phosphate pathway flux was 3.6% of glycolysis, and three non-oxidative pentose phosphate pathway exchange fluxes were calculated. Mass spectrometry was then used to compare fluxes through various pathways under hyperglycemic (26 mM) and euglycemic (5 mM) conditions. Under euglycemic conditions glutamine uptake doubled, but ATP production from glutamine did not significantly change. A new parameter measuring the Warburg effect (the ratio of lactate production flux to pyruvate influx through the mitochondrial pyruvate carrier) was calculated to be 21, close to upper limit of oxidative metabolism.Cancer cells exhibit metabolic patterns that differ significantly from those of terminally differentiated adult tissues. They require rapid production of both energy and biosynthetic precursors to sustain a high rate of proliferation. The network of biochemical pathways underlying these processes is complex. Most of the individual enzymatic conversions involved in this network have probably already been identified, but a comprehensive and quantitative description of the fluxes involved is lacking. Methods to produce such descriptions will likely be very useful in the design of new therapeutics that specifically target the metabolic abnormalities of cancer as well as in clinical implementation of non-invasive methods for detection of cancer and its therapeutic response.The kinetics of 13 C isotope labeling as monitored by NMR spectroscopy has been used to measure flux through various metabolic pathways of perfused isolated cells and organs and in vivo (1-4). Kinetic data provide estimates of absolute flux, whereas steady-state data measure relative flux. Both types of analysis require validated mathematical models, which have been formulated for the heart (5-10), liver (11-13), brain (14 -16), a...
Core@shell electrocatalysts for fuel cells have the advantages of a high utilization of Pt and the modification of its electronic structures toward enhancement of the activities. In this study, we suggest both a theoretical background for the design of highly active and stable core@shell/C and a novel facile synthetic strategy for their preparation. Using density functional theory calculations guided by the oxygen adsorption energy and vacancy formation energy, Pd3Cu1@Pt/C was selected as the most suitable candidate for the oxygen reduction reaction in terms of its activity and stability. These predictions were experimentally verified by the surfactant-free synthesis of Pd3Cu1/C cores and the selective Pt shell formation using a Hantzsch ester as a reducing agent. In a similar fashion, Pd@Pd4Ir6/C catalyst was also designed and synthesized for the hydrogen oxidation reaction. The developed catalysts exhibited high activity, high selectivity, and 4,000 h of long-term durability at the single-cell level.
Surgeons do not have to be discouraged from performing anterior decompression for the patients with cervical OPLL on the basis of age, severity of disease (preoperative Nurick grade or occupying ratio), irreversible changes in gray matter of the spinal cord (snake-eye appearance), or duration of symptoms. We should direct our attention to DM as a potent risk factor for cervical OPLL and try to clarify the mechanism by which DM possibly affected the functional recovery of the patients.
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