Scheduling with single carrier property restriction has a significant impact on system performance in Long Term Evolution (LTE) uplink (UL). Due to the unavoidable delay of control signaling, the scheduling decisions have great influence on the variation of inter-cell interference (ICI) which affects the performance of adaptive modulation and coding (AMC). Many studies have been carried out on the topic of resource allocation in single-carrier frequency division multiple access (SC-FDMA) system. Some of them deal with the ICI variation with inter-cell measurements or coordination. In this paper, we present the problem of frequency domain packet scheduling (FDPS), analyze the negative effects of ICI variation and develop our improved proportional fair (PF) scheduling algorithm based on the traditional one for LTE UL. Our proposed algorithm decreases the ICI variation and improves AMC accuracy without any inter-cell coordination. Compared with the traditional way, system level performance shows that at least 29% gain can be obtained at both the cell user average spectral efficiency and the cell edge user spectral efficiency with comparable proportional fairness in typical interference-limited scenario.
Chronic hepatitis B virus (HBV) infections are associated with the development of hepatocellular carcinoma (HCC). The HBV X protein (HBx) is thought to play an important role in the development of HBV-associated HCC. One fundamental HBx function is elevation of cytosolic calcium signals; this HBx activity has been linked to HBx stimulation of cell proliferation and transcription pathways, as well as HBV replication. Exactly how HBx elevates cytosolic calcium signals is not clear. The studies described here show that HBx stimulates calcium entry into cells, resulting in an increased plateau level of inositol 1,4,5-triphosphate (IP3)-linked calcium signals. This increased calcium plateau can be inhibited by blocking mitochondrial calcium uptake and store-operated calcium entry (SOCE). Blocking SOCE also reduced HBV replication. Finally, these studies also demonstrate that there is increased mitochondrial calcium uptake in HBx-expressing cells. Cumulatively, these studies suggest that HBx can increase mitochondrial calcium uptake and promote increased SOCE to sustain higher cytosolic calcium and stimulate HBV replication.
Walt Disney Imagineering and Disney Research Zürich are building a projector- camera toolbox to help create spatially augmented 3D objects and dynamic, interactive spaces that enhance the theme park experience by immersing guests in magical worlds. A related video can be seen here: http://youtu.be/wjrylXl0tTk. It shows examples of projection-based augmented reality techniques being employed in Disney theme parks.
Globally, hepatocellular carcinoma (HCC) is the fifth most common cancer and the third highest cause of cancer-associated deaths. Although the development of HCC has been linked to exposure to various toxins or infectious agents, the majority of HCC cases are associated with chronic hepatitis B virus (HBV) infections [reviewed in (Block et al, 2003; Seeger et al, 2007)]. Worldwide, there are an estimated 350 million cases of chronic HBV infections, and approximately 25% of chronically HBV-infected individuals will eventually develop HCC [(Beasley et al, 1981); reviewed in (Seeger et al, 2007)]. The high global incidence of chronic HBV infections, high mortality rate of individuals with HCC, increased prevalence of HCC, and the close association between chronic HBV infections and HCC development have generated intense interest in understanding the molecular mechanisms that underlie the development of HBV-induced HCC. In this chapter, we provide a review of HBV biology and potential mechanisms that link a chronic HBV infection to the development of HCC. We specifically focus on activities of the HBV X protein (HBx), a multifunctional HBV protein that can alter hepatocyte physiology and stimulate HBV replication. While a brief survey of HBx activities that could influence HCC development is provided, we emphasize HBx regulation of intracellular calcium signaling and cell proliferation pathways as HBx activities that could potentially influence hepatocyte transformation.
The Thermal Interactive Media (TIM) display represents an engaging new form of tangible user interface that enables users to control the interaction and blending of multiple video streams through the physical mixing of water at different temperatures.
The bioequivalence of two brands of rivastigmine capsules, of different salt forms, was demonstrated in six healthy beagle dogs after a single oral dose in a randomized cross-over study. Reference (Rivastigmine hydrochloride, Sunve, CN) and test (Rivastigmine tartrate, Novartis, CH) products were administered to fasting beagles on two treatment days separated by a two-day washout period; blood samples were collected at specified time intervals, and the plasma was separated and analyzed for rivastigmine using a validated GC-MS method. The pharmacokinetic parameters AUC(0-t), AUC(0-infinity), C-max, T-max and t(1/2) were compared statistically to evaluate bioequivalence between the two brands, using the statistical modules recommended by the State Food and Drug Administration (SFDA) of China. The analysis of variance (ANOVA) did not show any significant difference between the two formulations and 90% confidence intervals fell within the acceptable ranges for bioequivalence. Based on these statistical inferences it was concluded that the two brands exhibited comparable pharmacokinetic profiles and that Sanwei's Rivastigmine hydrochloride was bioequivalent to Rivastigmine tartrate of Novartis, CH.
More than 350million people worldwide are chronically infected with the human hepatitis B virus (HBV). Chronic HBV infections are associated with the development of hepatocellular carcinoma. While the mechanism of HBV-associated carcinoma remains undefined, it is thought to involve a combination of a continuous inflammatory response to HBV-infected hepatocytes and activities of HBV proteins such as the HBV X protein (HBx). HBx stimulates HBV replication; however, the mechanism by which HBx stimulates HBV replication remains incompletely understood. Studies performed with the woodchuck hepatitis virus (WHV) in woodchucks demonstrated that a C-terminally truncated mutant of the WHV X protein could not stimulate WHV replication. However, whether the C-terminus of HBx is important for HBx-stimulation of HBV replication is unclear. We have constructed C-terminal truncation mutants of HBx and have demonstrated that the C-terminus of HBx impacts HBx stability, HBx activation of transcription, and HBx stimulation of HBV replication. These observations highlight the impact of the HBx C-terminus on HBx activities and the importance of directly analyzing HBx expression and functions in HBV-associated tumors that contain chromosomal integrants of HBV with truncations of the HBx gene.
Abstract In gene mapping of complex traits, classical association approaches, including the standard chi-squared statistics or logistic regression meth- ods, have been used to find susceptibility genes with modest effects. A novel statistical method, recursive partitioning, has recently been introduced in association studies. We use this new method,to as- sess association between the human,leukocyte antigen system (HLA) and an autoimmune disease, multiple sclerosis (MS). In particular, we model the association between HLA class II loci and MS using recur- sive partitioning and then model the association between HLA class I loci and MS, controlling for class II loci, using logistic regression. We have access to genotype data on 3174 MS patients and healthy con- trols from the Swedish and Norwegian populations. Our results differ slightly from previous studies that use logistic regression exclusively
Microwave distillation with concomitant solid-phase microextraction (MD-SPME) coupled with GC/MS was developed for identifying volatile compounds in the dried flowers of Chrysanthemum morifolium (CM). Different experimental parameters, including SPME fiber coating, microwave power, irradiation time, and water volume were optimized. The best results were obtained using carboxen/polydimethylsiloxane fiber with microwave irradiation at 400 W for 3 min and the addition of 1 mL water into 1.0 g sample. The proposed method allowed the isolation, extraction, and concentration of volatile compounds to be completed in a single step. This MD-SPME-GC/MS method has also been compared to the conventional steam distillation method followed by GC/MS for this identification. Thirty-two volatile compounds were identified using the newly developed MD-SPME-GC/MS process. Relative standard deviation values of <9.8% demonstrate good repeatability. In comparison, 27 compounds were identified by traditional steam distillation-GC/MS. Therefore, the proposed MD-SPME-GC/MS method is simple, rapid, and efficient for identifying volatile compounds in CM.
In this paper, microwave distillation and solid-phase microextraction coupled with gas chromatography-mass spectrometry (MD-SPME/GC-MS) was developed for the analysis of essential components in safflower. Using the MD-SPME technique, the isolation, extraction and concentration of volatile compounds in safflower were carried out in only one step. Some parameters affecting the extraction efficiency such as SPME fiber coating, microwave power, irradiation time and the volume of water added were optimized. The optimal experiment parameters obtained were: 65 microm CW/DVB SPME fiber, a microwave power of 400 W, an irradiation time of 3 min and water volume of 1 mL. The proposed method has been compared with conventional steam distillation (SD) for extraction of essential oil compounds in safflower. Using MD-SPME followed by GC-MS, 32 compounds in safflower were separated and identified, which mainly included paeonol, alpha-asarone, beta-asarone, 1-methyl-4-(2-propenyl)-benzene and diethenyl-benzene, whereas only 18 compounds were separated and identified by conventional SD followed by GC-MS. The relative standard deviation (R.S.D.) values of less than 10% show that the proposed method has good reproducibility. The results show that MD-SPME/GC-MS is a simple, rapid, effective method for the analysis of volatile oil components in safflower.
In this study, gas chromatography–mass spectrometry (GC–MS) following microwave distillation and solid-phase microextraction (MD–SPME) was developed for the analysis of essential oil compounds in fresh ginger. In the proposed method, the isolation, extraction and concentration of volatile components in ginger were carried out in one single step, using the MD–SPME technique, and the analytes on the SPME fiber were analyzed by GC–MS. Some parameters, including SPME fiber coating, microwave power and irradiation time, were optimized. The optimal experiment parameters obtained were: 65μm PDMS/DVB SPME fiber, a microwave power of 400W and an irradiation time of 2min. To demonstrate its feasibility, MD–SPME was compared with conventional SPME for the extraction of essential oil compounds in fresh ginger. Using MD–SPME followed by GC–MS, 54 compounds were separated and identified in ginger, which mainly included geranial (5.25%), zingiberene (15.48%), β-sesquiphellandrene (5.54%) and β-phellandrene (22.84%), whereas only 39 compounds were separated and identified by conventional SPME followed by GC–MS. The relative standard deviation (R.S.D.) values of less than 10% show that the proposed method has good repeatability. The result show that MD–SPME, followed by GC–MS, is a simple, rapid, solvent-free method for the determination of volatile compounds in ginger.
Phycobilisomes, the light-harvesting complexes of cyanobacteria and red algae, contain two to four types of chromophores that are attached covalently to seven or more members of a family of homologous proteins, each carrying one to four binding sites. Chromophore binding to apoproteins is catalyzed by lyases, of which only few have been characterized in detail. The situation is complicated by nonenzymatic background binding to some apoproteins. Using a modular multiplasmidic expression-reconstitution assay in Escherichia coli with low background binding, phycobilin:cystein-84 biliprotein lyase (CpeS1) from Anabaena PCC7120, has been characterized as a nearly universal lyase for the cysteine-84-binding site that is conserved in all biliproteins. It catalyzes covalent attachment of phycocyanobilin to all allophycocyanin subunits and to cysteine-84 in the beta-subunits of C-phycocyanin and phycoerythrocyanin. Together with the known lyases, it can thereby account for chromophore binding to all binding sites of the phycobiliproteins of Anabaena PCC7120. Moreover, it catalyzes the attachment of phycoerythrobilin to cysteine-84 of both subunits of C-phycoerythrin. The only exceptions not served by CpeS1 among the cysteine-84 sites are the alpha-subunits from phycocyanin and phycoerythrocyanin, which, by sequence analyses, have been defined as members of a subclass that is served by the more specialized E/F type lyases.
A liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) method was developed and validated for the assay of glucosamine sulfate in human plasma. Plasma proteins were precipitated by acetonitrile, followed by vortex mixing and centrifugation. The supernatant was transferred and derivatized with phenyl iso-thiocyanate in acetonitrile at 60 degrees C for 40 min. Chromatographic separation was performed on a C(18) column (Inertsil ODS-3 150 x 2.1 mm i.d., 5 microm, JP) with a mobile phase gradient consisting of 0.2% acetic acid (aqueous) and methanol at a flow-rate of 0.3 mL/min. MS detection using electrospray ionization (ESI) as an interface was used in single ion monitoring mode to determine positive ions at m/z 297. This method was shown to be selective and sensitive for glucosamine sulfate. The limit of detection was 35 ng/mL for glucosamine sulfate in plasma and the linear range was 0.1-20 microg/mL in plasma with a correlation coefficient (r) of 0.9991. The relative standard deviations (RSDs) of intra-day and inter-day assays were 8.7-11.4 and 9.8-12.6%, respectively. Extraction recoveries of glucosamine sulfate in plasma were greater than 73%. This method proved to be simple, reproducible and feasible for pharmacokinetic studies of glucosamine sulfate in healthy volunteers after a single oral administration (1500 mg). The pharmacokinetic parameters and relative bioavailabilities were investigated for both domestic glucosamine sulfate tablet and capsule preparations compared with an imported capsule product.
In this study, a simple, rapid, and sensitive method was developed and validated for the quantification of valproic acid (VPA), an antiepileptic drug, in human plasma, which was based on water-phase derivatization followed by headspace solid-phase microextraction (HS-SPME) and gas chromatography/mass spectrometry (GC/MS). In the proposed method, VPA in plasma was rapidly derivatized with a mixture of isobutyl chloroformate, ethanol and pyridine under mild conditions (room temperature, aqueous medium), and the VPA ethyl ester formed was headspace-extracted and simultaneously concentrated using the SPME technique. Finally, the analyte extracted on SPME fiber was analyzed by GC/MS. The experimental parameters and method validations were studied. The optimal conditions were obtained: PDMS fiber, stirring rate of 1100 rpm, sample temperature of 80 degrees C, extraction time of 20 min, NaCl concentration of 30%. The proposed method had a limit of quantification (0.3 microg/mL), good recovery (89-97%) and precision (RSD value less than 10%). Because the proposed method combined a rapid water-phase derivatization with a fast, simple and solvent-free sample extraction and concentration technique of SPME, the sample preparation time was less than 25 min. This much shortens the whole analysis time of VPA in plasma. The validated method has been successfully used to analyze VPA in human plasma samples for application in pharmacokinetic studies. All these results show that water-phase derivatization followed by HS-SPME and GC/MS is an alternative and powerful method for fast determination of VPA in biological fluids.
A simple, rapid and sensitive high-performance liquid chromatographic method for the simultaneous determination of captopril and hydrochlorothiazide in human plasma samples was developed. Captopril was derivatized with 2,4-dibromoacetophenone (pBPB) to form a captopril-pBPB adduct. From acidified serum plasma samples, the hydrochlorothiazide and derivatized captopril was extracted with 5 ml ether, then with 5 ml dichloromethane. Effective chromatographic separation was achieved using a C-18 column (DIAMONSIL 150 mm x 4 mm i.d., 5 mu m) based on an acetonitrile-trifluoroacetic acid-water gradient elution at a flow rate of 1.2 ml/min.The internal standard (IS), derivatized captopril and hydrochlorothiazide were detected at 263 nm and were eluted at 4.2, 6.8 and 16.9 min, respectively. No endogenous substances were found to interfere. The limit of quantification for hydrochlorothiazide and derivatized captopril in plasma were 3.3 and 7 ng/ml. The calibration curve for derivatized captopril showed linearity in the range 20-4000 ng/ml, with a regression coefficient corresponding to 0.9993 and the coefficient of the variation of the points of the calibration curve being lower than 10%. The calibration curve for hydrochlorothiazide showed linearity in the range 10-1200 ng/ml, with a regression coefficient corresponding to 0.9999 and the coefficient of the variation of the points of the calibration curve being lower than 10%. The method was suitably validated and successfully applied to the determination of captopril and hydrochlorothiazide in human plasma samples. (c) 2005 Elsevier B.V. All rights reserved.
In the study, we developed a simple, rapid and sensitive method for the determination of tiopronin (TP) in human plasma, which was based on derivatization with p-bromophenacyl bromide (p-BPB) followed by liquid–liquid extraction and reverse-phase HPLC-UV detection. For the first time, the p-BPB was introduced into the derivatization of TP. The thiol group of TP was trapped with p-BPB to form a TP-p-BPB adduct, which can be very suitable for UV detection. From acidified plasma samples, the derivatized TP was extracted with 5mL dichloromethane. Effective chromatographic separation was achieved using a C18 column (DIAMONSIL 150mm×4mm i.d., 5μm) based on an acetonitrile–water–trifluoroacetic acid (40:59.88:0.12, v/v/v) elution at a flow-rate of 1mL/min. The IS and the derivatized TP were detected at 263nm. No endogenous substances were found to interfere. The limit of quantification for derivatized TP (TP-p-BPB) in plasma was 40ng/mL. The calibration curve for the derivatized TP showed linearity in the range 0.04–4μg/mL with a regression coefficient corresponding to 0.9991 and the coefficient of the variation of the points of the calibration curve being lower than 10%. Extraction recoveries of the derivatized TP in plasma were greater than 72%. The method was suitably validated and successfully applied to determination of TP in human plasma samples.
An LC-ESI-MS method was developed and validated for the assay of apomorphine in canine plasma using one-step liquid-liquid extraction. The analytes were separated on a Phenomenex Gemini C18 (150 mm x 2.0 mm id 3 microm) column and determined by MS in the positive ion mode. The linear range was 0.4-40 ng/mL with an LOD of 0.2 ng/mL for apomorphine in plasma. The intraday and interday precision and accuracy of quality control samples were < 5.9% RSD and < 7.5% bias for apomorphine. Extraction recoveries were > 80%. The validated method was successfully applied to analyze canine plasma samples in a pharmacokinetic study of apomorphine in dogs and detailed pharmacokinetic parameters were calculated.
A simple ion-pair reversed-phase high-performance liquid chromatographic (RP-HPLC) method has been developed for determination of tegaserod maleate and related impurities in tablet dosage forms. The mobile phase was 60:40 (v/v) acetonitrile-25 mmol L −1 sodium dodecyl sulfate, adjusted to pH 2.6 with glacial acetic acid. A C18 column was used as stationary phase and UV detection was at 314 nm. The method was optimized and validated. Response was linearly dependent on concentration between 0.1 and 100 µg mL −1 with a limit of quantification (LOQ) of 0.1 µg mL −1 for tegaserod maleate (S/N = 10). Under optimum conditions, tegaserod maleate was successfully separated from related substances, including 5-methoxyindole-3-carboxaldehyde remaining after synthesis and other impurities possibly resulting from oxidization and decomposition. The excipients did not interfere with assay of tegaserod maleate in tablet dosage forms. It is suggested that the proposed method can be used for routine quality control and dosage-form assay of tegaserod maleate.
Mark R. Mine合作论文数University of North Carolina at Chapel Hill
Department of Computer Science2