Developing a psychological care competences framework for nurses in China: a mixed methods study.

BACKGROUND: With social transformation, rapid economic development and deepening awareness of psychological health in China, people's demand for psychological health services is becoming increasingly urgent. A key challenge for Chinese medical organizations is to train enough qualified psychological care nurses. A greater understanding of psychological care competences (PCC) can help in clinical nurse selection, training, and assessment. OBJECTIVE: To develop a PCC framework for Chinese nurses and obtain a consensus on the framework among experts. METHODS: A descriptive mixed methods study was designed consisting of a literature review and semi-structured interviews followed by three Delphi rounds. The experts (n = 16) involved were nurses, nursing managers and educators from nine Chinese provinces with a specific interest in psychological care. Descriptive statistics assisted in data analysis. RESULTS: Using the Iceberg Model as a theoretical foundation, five main dimensions and associated subdomains were integrated from 39 chosen articles. The semi-structured interviews with 24 nursing managers and nurses confirmed all of the themes from the literature review while generating new themes, both of which were incorporated into the initial PCC framework. After three Delphi rounds, the experts reached consensus on the PCC framework, including five domains (knowledge, skills, professional ethics, personal traits, internal motivations) and 22 subdomains with connotations. The response rate (RR) values for the three rounds of consultation were 80.00%, 87.50% and 92.86%, the composite reliability (Cr) values were 0.89-0.90, and the Kendall coordination coefficients were 0.155-0.200 (P < 0.05). CONCLUSIONS: On the basis of the Iceberg Model, literature review and qualitative research methods along with Delphi technique were used to develop a scientific and systematic PCC framework. The research methods were feasible and the results were reliable, thereby providing a basis for adopting this framework into nursing education. A formal assessment tool should be developed to test the PCC of nurses in clinical practice.

Computational pathology: A survey review and the way forward.

Computational Pathology (CPath) is an interdisciplinary science that augments developments of computational approaches to analyze and model medical histopathology images. The main objective for CPath is to develop infrastructure and workflows of digital diagnostics as an assistive CAD system for clinical pathology, facilitating transformational changes in the diagnosis and treatment of cancer that are mainly address by CPath tools. With evergrowing developments in deep learning and computer vision algorithms, and the ease of the data flow from digital pathology, currently CPath is witnessing a paradigm shift. Despite the sheer volume of engineering and scientific works being introduced for cancer image analysis, there is still a considerable gap of adopting and integrating these algorithms in clinical practice. This raises a significant question regarding the direction and trends that are undertaken in CPath. In this article we provide a comprehensive review of more than 800 papers to address the challenges faced in problem design all-the-way to the application and implementation viewpoints. We have catalogued each paper into a model-card by examining the key works and challenges faced to layout the current landscape in CPath. We hope this helps the community to locate relevant works and facilitate understanding of the field's future directions. In a nutshell, we oversee the CPath developments in cycle of stages which are required to be cohesively linked together to address the challenges associated with such multidisciplinary science. We overview this cycle from different perspectives of data-centric, model-centric, and application-centric problems. We finally sketch remaining challenges and provide directions for future technical developments and clinical integration of CPath. For updated information on this survey review paper and accessing to the original model cards repository, please refer to GitHub. Updated version of this draft can also be found from arXiv.

Experimental study of the mechanism of prepulse current on Z-pinch plasma using Faraday rotation diagnosis.

The prepulse current is an effective way to optimize the load structure and improve the implosion quality of the Z-pinch plasma. Investigating the strong coupling between the preconditioned plasma and pulsed magnetic field is essential for the design and improvement of prepulse current. In this study, the mechanism of the prepulse current on the Z-pinch plasma was revealed by determining the two-dimensional magnetic field distribution of preconditioned and nonpreconditioned single-wire Z-pinch plasma with a high-sensitivity Faraday rotation diagnosis. When the wire was nonpreconditioned, the current path was consistent with the plasma boundary. When the wire was preconditioned, the distributions of current and mass density presented good imploding axial uniformity, and the imploding speed of the current shell was higher than that of the mass shell. In addition, the mechanism of the prepulse current suppressing the magneto-Rayleigh-Taylor instability was revealed, which formed a sharp density profile of the imploding plasma and slowed the shock wave driven by the magnetic pressure. This discovery is essential and instructive for the design of preconditioned wire-array Z-pinch experiments.

Ab initio molecular dynamics calculations on electron ionization induced fragmentations of C4F7N and C5F10O for understanding their decompositions under discharge conditions.

C4F7N and C5F10O are the most promising SF6 alternatives as eco-friendly insulating gaseous mediums in electrical engineering. It is necessary to clarify their electrical stability and decomposition mechanisms. In this work, we first introduced our experimental results for decomposition products of C4F7N/CO2 and C5F10O/synthetic air mixtures under partial discharge and spark discharge conditions. Then, we performed ab initio molecular dynamics (AIMD) simulations on the typical decomposition products. The simulations were performed under standard electron impact mass spectrometry (EI-MS); thus, the statistical results of the mass spectra were compared with those of the experimentally obtained standard mass spectra from the NIST database. The AIMD simulation method in simulating the electron-induced ionization process was verified and found to be reliable. Finally, the calculations were also performed for C4F7N and C5F10O with incident electron energies of 20 eV and 70 eV, respectively. The dominant pathway for both gases is the formation of CF3+ with the fracture of the C-C bond. The AIMD simulation is able to predict the decomposition channels after electron-impact ionization without any preconceived knowledge of fragmentation pathways, which provides a novel insight into understanding the decomposition mechanisms of C4F7N and C5F10O under different discharge conditions with different energies.

Hydrothermal Aging Mechanism and Modeling for SCR Catalysts.

Based on the activity evaluation and characterization test, we explored the hydrothermal aging mechanism of a vanadium-based SCR catalyst and constructed a dual-site hydrothermal aging kinetic model in this study. The vanadium-based catalyst contains Brønsted acidic sites and Lewis acidic sites, which show different sensitivities to hydrothermal aging, and the reduction of active sites is the main reason for the NOx conversion efficiency reduction after hydrothermal aging. The ammonia storage capacities of both sites have a high correlation coefficient with the NOx conversion efficiency. Based on the method of NH3-TPD curve peak resolution, we quantified the transformations of the two active sites and established the relationship between the site density, the aging temperature, and the duration to determine the aging factor. Then, a hydrothermal aging kinetic model was constructed, and the parameter identification and verification of the model were carried out through flow reactor experiments. The results show that the model constructed in this study can accurately reflect the catalyst activity after hydrothermal aging.

Measurement of dynamic atomic polarizabilities of Al at 19 wavelengths from 420†nm to 680†nm in electrical exploding wire experiments.

The dynamic polarizabilities of Al atom at 19 wavelengths from 420 nm to 680 nm are measured experimentally for the first time. A 15 µm diameter Al wire is heated to the gas/ microdrop stage using a 3 kA, 25 ns pulsed current, and the energy deposition when the resistive voltage reaches its peak is 4.7 eV·atom-1, which is higher than the atomization enthalpy of Al but much lower than its first ionization potential. Two laser interferometric images of the Al gas are obtained simultaneously using a 532 nm laser and an optical parametric oscillator laser. Then an integrated phase method is used to reconstruct the Al atomic linear density distribution based on the known atomic polarizability at 532 nm, which acts as a bridge between the two interferograms to obtain the relative atomic polarizability value at a specific wavelength with respect to the value at 532 nm. The measured dynamic polarizability of Al atom decreases from 13.5×10-24 cm3 to 9.4×10-24 cm3 as the wavelength increases from 420 nm to 680 nm with a measurement error of approximately ±10%. The experimental result fits well with an uncoupled Hartree-Fock approximation, and the reconstructed static polarizability of 8.13 ± 0.79×10-24 cm3 is well matched with reference measurement results.

Improved measurement method for the Faraday rotation distribution using beam splitting.

In this work, two Faraday channels and one shadow channel are constructed by two non-polarizing beam splitters and one reflector to measure the Faraday rotation distribution. The intensity of the Faraday and shadow images is related to the state of polarization (SOP) of the incident light, thus achieving two-dimensional accurate measurement. The measurement sensitivity is influenced by the settings of two polarization analyzers in the Faraday channels and the parameters of beam splitters, which are explored numerically and verified with experiments. The fluctuation of the probe light is eliminated by using three evaluation indexes. Also, the measurement range and error sources under different experimental settings are discussed.

Measurement of magnetic field distribution produced by high-current pulse using Zeeman splitting of Na emission distributed by laser ablation.

Measurement of the magnetic field distribution in Z-pinch experiments remains an ongoing challenge. We present a method of measuring the radial distribution of the magnetic field around a copper rod using Zeeman splitting of sodium (Na) emission lines, in which an Na layer is formed by the laser ablation of NaCl crystals on a load surface. The load consists of a copper rod of 2 mm diameter and is pre-covered on its surface by the NaCl crystals. An 8 ns pulsed laser with an energy of 1 J and wavelength of 532 nm is focused on the crystals. The Na plasma is produced and expands from the surface of the copper rod into a vacuum. After applying a pulsed current with a peak value of 375 kA to the load, the Na 3s-3p doublet displays significant Zeeman splitting patterns. The self-luminosity of the Na plasma is recorded by a spectrometer coupled with an intensified charge-coupled device camera from an end-on view to eliminate the effects of different observing angles and Doppler shifts. We determine the magnetic field by fitting the measured spectra with the calculated results of the Voigt profile. The measurable range of radial position is 5-7 mm, and the corresponding magnetic field is 5-15 T. The averaged error of curve fitting is less than 12%.

Anlotinib Monotherapy for Refractory Metastatic Colorectal Cancer: A Double-Blinded, Placebo-Controlled, Randomized Phase III Trial (ALTER0703).

BACKGROUND: Treatment options for refractory metastatic colorectal cancer (mCRC) were limited. Anlotinib is a novel multitarget tyrosine kinase inhibitor. ALTER0703 study was conducted to assess efficacy and safety of anlotinib for patients with refractory mCRC. MATERIALS AND METHODS: This was a multicenter, double-blinded, placebo-controlled, randomized phase III trial involving 33 hospitals in China. Patients had taken at least two lines of therapies were 2:1 randomized to receive oral anlotinib (12 mg/day; days 1-14; 21 days per cycle) or placebo, plus best supportive care. Randomization was stratified by previous VEGF-targeting treatments and time from diagnosis to metastases. The primary endpoint was overall survival (OS). The secondary endpoints were progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), quality of life (QoL), and safety. RESULTS: A total of 419 patients (anlotinib: 282; placebo: 137) were treated from December 2014 to August 2016. The median PFS was improved in anlotinib group (4.1 months; 95% confidence interval [CI], 3.4-4.5) over placebo group (1.5 months; 95% CI, 1.4-1.5), with a hazard ratio (HR) of 0.34 (95% CI, 0.27-0.43; p < .0001). However, median OS was similar between two groups (8.6 months; 95% CI, 7.8-9.7 vs. 7.2 months; 95% CI, 6.2-8.8; HR, 1.02; p = .870). Improvements of ORR and DCR were observed in anlotinib over placebo. The most common grade ≥ 3 anlotinib related adverse events were hypertension (20.92%), increased γ-GT (7.09%), and hand-foot skin reaction (6.38%). CONCLUSION: Anlotinib was tolerated in Chinese patients with refractory mCRC. Although OS did not reach significant difference, anlotinib still provided clinical benefits by substantially prolonged PFS in these patients. IMPLICATIONS FOR PRACTICE: In this randomized clinical trial that included 419 patients with refractory metastatic colorectal cancer, substantial prolonged in progression-free survival was noted in patients who received anlotinib compared with those given placebo. Improvements on objective response rate and disease control rate was also observed in anlotinib group. However, overall survival was similar between the two groups. In a word, in third-line or above treatment of Chinese patients with refractory metastatic colorectal cancer, anlotinib provided clinical benefit by significantly prolonged progression-free survival.

P-glycoprotein Substrate Assessment in Drug Discovery: Application of Modeling to Bridge Differential Protein Expression Across In Vitro Tools.

P-glycoprotein (P-gp) efflux assay is an integral part of discovery screening, especially for drugs requiring brain penetration as P-gp efflux ratio (ER) inversely correlates with brain exposure. However, significant variability in P-gp ER generated across cell lines can lead to misclassification of a P-gp substrate and subsequently disconnect with brain exposure data. We hypothesized that the ER depends on P-gp protein expression level in the in vitro assay. Quantitative proteomics and immunofluorescence staining were utilized to characterize P-gp protein expression and localization in four recombinant cell lines, over-expressing human or mouse P-gp isoforms, followed by functional evaluation. Efflux data generated in each cell line was compared against available rodent brain distribution data. The results suggested that the cell line with highest P-gp expression (hMDCK-MDR1 sourced from NIH) led to greatest dynamic range for efflux; thus, proving to be the most sensitive model to predict brain penetration. Cell lines with lower P-gp expression exhibited the greatest tendency for compound-dependent in vitro efflux saturation leading to false negative results. Ultimately, P-gp kinetics were characterized using a compartmental model to generate system-independent parameters to resolve such discrepancy. This study highlights the need for careful choice of well characterized P-gp in vitro tools and utility of modeling techniques to enable appropriate interpretation of the data.

A gas-insulated mega-ampere-class linear transformer driver with pluggable bricks.

This paper presents the design and test of a gas-insulated linear transformer driver (LTD) cavity aimed at the Z-pinch experimental device CZ-34. The LTD cavity has a diameter of 2290 mm and a height of 346 mm. It consists of 23 main bricks and 1 trigger brick. Each main brick is comprised of two 100 nF capacitors connected electrically in series with a field-distortion gas switch. The trigger brick is comprised of two 50 nF capacitors connected in series with a compact multi-gap gas switch. All bricks are placed in the cavity filled with compressed SF6 and are pluggable like drawers. The trigger pulse generated by the trigger brick passes through an azimuthal transmission line to the trigger ring and makes the main bricks discharge synchronously. The LTD cavity can deliver ∼1 MA current pulse with a rise time of 115 ns to 0.08 Ω liquid resistance load when the charging voltage is ±100 kV, which is in good agreement with the circuit simulation results. Experimental results demonstrate the successful application of using gas insulation and pluggable bricks. The technical feasibility of the charging configuration, triggering method, and isolation resistors is verified. There is little difference in output performance as return-current rods replaced the outside metal cylinder, which provides a new path for the design of LTD cavities in series.

A repetitive high current pulse generator for high flux electrothermal plasma jets.

Power sources play an important role in the characteristics and the applications of the electrothermal (ET) plasma as an edge localized mode (ELM) heat flux simulator. A repetitive high current ET plasma source with the capability of working at a 10 Hz repetition rate and peak current 7.5 kA is presented in this paper. By controlling the sequence of discharge of ten pulse power modules, a repetitive high heat flux plasma jet can be generated. A two-stage capillary structure is presented, and its repetitive trigger driving circuit based on surface flashover ignition is designed to achieve reliable and repetitive discharge. The topology of the inductive and capacitive (LC) series resonant circuit is applied to the charging system of the pulsed power source. The charging current is limited to 500 A with a charging time of 3.5 ms, and the ratio of the charging voltage to the operating voltage is 1.85. A diode and a power resistor in series are used to suppress the negative overvoltage, which is helpful to increase the thyristors' operating reliability. Using the designed repetitive ET plasma source, the characteristics of the ET plasma jet are investigated by measuring the voltages and currents and by obtaining images of the discharges. Experimental results show that the repetitive ET plasma generator can be used as an appropriate way to simulate the ELM-like heat flux plasma.

Albumin-Mediated Uptake Improves Human Clearance Prediction for Hepatic Uptake Transporter Substrates Aiding a Mechanistic In Vitro-In Vivo Extrapolation (IVIVE) Strategy in Discovery Research.

This study focused on exploring various in vitro to in vivo extrapolation (IVIVE) approaches with the primary goal of improving human hepatic clearance (CL) prediction for OATP substrates. To that effect, the impact of albumin-mediated uptake in human hepatocytes was investigated. In vitro hepatic uptake assay using suspended human hepatocytes was performed with 16 selected OATP substrates to determine the uptake CL in the absence and presence of 4% BSA and unbound hepatocyte to media partition coefficient (Kpuu). Substantial enhancement of the unbound uptake CL (PSu,inf) was observed in the presence of 4% BSA, demonstrating "albumin-mediated" uptake. Prediction of human hepatic CL was performed using two non-traditional IVIVE approaches: initial uptake CL (PSu,inf) and intrinsic metabolic CL (CLint,met) corrected by Kpuu based on extended clearance concept. Compared to traditional IVIVE using CLint,met only, the two tested IVIVE approaches significantly improved the prediction of human hepatic CL. Particularly, direct extrapolation from PSu,inf (+BSA) showed the most robust correlation with in vivo human hepatic CL for all 16 compounds with bias of 1.9-2.0 for two lots of human hepatocytes, respectively. In addition, PSu,inf (+BSA) and Kpuu were also determined in suspended cynomolgus monkey hepatocytes. Prediction of monkey hepatic CL was improved by both approaches, although with more bias compared to human. These results suggested supplementing 4% BSA in human hepatocyte uptake assay provides a useful tool to characterize hepatic uptake CL for OATP substrates, enabling more accurate human CL prediction without any empirical scaling factor (ESF).

Comparison of In Vitro to In Vivo Extrapolation Approaches for Predicting Transporter-Mediated Hepatic Uptake Clearance Using Suspended Rat Hepatocytes.

Clearance (CL) prediction remains a significant challenge in drug discovery, especially when complex processes such as drug transporters are involved. The present work explores various in vitro to in vivo extrapolation (IVIVE) approaches to predict hepatic CL driven by uptake transporters in rat. Broadly, two different IVIVE methods using suspended rat hepatocytes were compared: initial uptake CL (PSu,inf) and intrinsic metabolic CL (CLint,met) corrected by unbound hepatocytes to medium partition coefficient (Kpuu). Kpuu was determined by temperature method (Temp Kpuu,ss), homogenization method (Hom Kpuu,ss), and initial rate method (Kpuu,V0). In addition, the impact of bovine serum albumin (BSA) on each of these methods was investigated. Twelve compounds, which are known substrates of organic anion-transporting polypeptides representing diverse chemical matter, were selected for these studies. As expected, CLint,met alone significantly underestimated hepatic CL for all the test compounds. Overall, predicted hepatic CL using PSu,inf with BSA, Hom Kpuu,ss with BSA, and Temp Kpuu,ss showed the most robust correlation with in vivo rat hepatic CL. Adding BSA improved hepatic CL prediction for selected compounds when using the PSu,inf and Hom Kpuu,ss methods, with minimal impact on the Temp Kpuu,ss and Kpuu,V0 methods. None of the IVIVE approaches required an empirical scaling factor. These results suggest that supplementing rat hepatocyte suspension with BSA may be essential in drug discovery research for novel chemical matters to improve CL prediction. SIGNIFICANCE STATEMENT: The current investigation demonstrates that hepatocyte uptake assay supplemented with 4% bovine serum albumin is a valuable tool for estimating unbound hepatic uptake clearance (CL) and Kpuu. Based upon the extended clearance concept, direct extrapolation from these in vitro parameters significantly improved the overall hepatic CL prediction for organic anion-transporting polypeptide substrates in rat. This study provides a practical in vitro to in vivo extrapolation strategy for predicting transporter-mediated hepatic CL in early drug discovery.

Protein Phosphorylation Dynamics Under Carbon/Nitrogen-Nutrient Stress and Identification of a Cell Death-Related Receptor-Like Kinase in Arabidopsis.

Nutrient availability, in particular the availability of sugar [carbon (C)] and nitrogen (N), is important for the regulation of plant metabolism and development. In addition to independent utilization of C and N nutrients, plants sense and respond to the balance of C and N nutrients (C/N-nutrient) available to them. High C/low N-nutrient stress has been shown to arrest early post-germinative growth while promoting progression to senescence in Arabidopsis. Although several signaling components of the C/N-nutrient response have been identified, the inclusive molecular basis of plant C/N-nutrient response remains unclear. This proteome analysis evaluated phosphorylation dynamics in response to high C/low N-nutrient stress. Phosphoproteomics under conditions of C/N-nutrient stress showed a global change in the phosphorylation status of proteins, including plasma membrane H+-ATPase, carbon and nitrogen metabolic enzymes and signaling proteins such as protein kinases and transcription factors. Further analyses suggested that SNF1-related protein kinase 1 (SnRK1) is involved in primary C/N-nutrient signal mediation via the transcriptional regulation of C/N-regulatory kinases. We also identified a leucine-rich repeat receptor-like kinase with extracellular malectin-like domain, named as LMK1, which was shown to possess cell death induction activity in plant leaves. These results provide important insight into the C/N-nutrient signaling pathways connecting nutrition stress to various cellular and physiological processes in plants.

New Findings in Hydrothermal Deactivation Research on the Vanadia-Selective Catalytic Reduction Catalyst.

Considering the risks of hydrothermal deterioration in vehicles, power plants, and oceangoing vessels, V2O5-WO3/TiO2 catalysts were subject to hydrothermal and thermal aging at 600, 625, 635, and 650 °C for 4-48 h. The different ratio and significant loss of active sites are main reasons for catalyst deactivation. Both Lewis and Brønsted acid sites are involved in the selective catalytic reduction reaction. Brønsted acid sites are more susceptible. High temperature plays a major role in the aging. It causes sintering, particle growth, and the anatase phase transition. Phase transformation turns out to be less important than sintering. Sintering leads to the reduction of the BET surface area, which in turn causes decrease of NH3 adsorption amount and changes of active sites. Aging time can accelerate the degree of deactivation. It also helps to change the proportion of active sites. Water vapor has no significant effect on NO X conversion rates.

Nanoparticle self-assembled technique applied to a whispering-gallery-mode laser.

The low threshold microlaser is the fundamental component of integrated optical circuits. The fabrication method of the microcavity determines the dimension and threshold of lasers, while the doping method limits the available gain materials and emitted wavelength. Here we propose a silica nanoparticles self-assembly technique to fabricate a microlaser with a radius of ∼100 um and Q factor of 2000. The aggregation state of gain molecules is investigated to be J-type dimers with high fluorescence to support the laser generation. The laser can emit a ∼600 nm waveband multimode laser with a low threshold of ∼12 µJ. Such a laser is promising as a coherent light source integrated on the photonic microchips and opens up a new orientation in material science.

Expression of Reg IV and SOX9 and their correlation in human gastric cancer.

BACKGROUND: Reg IV is a member of the regenerating gene family and has been demonstrated to be overexpressed in gastric cancer. However, the functional mechanism of Reg IV in gastric cancer is still unclear. METHODS: Expression of Reg IV and SOX9 were investigated by immunohistochemistry (IHC) and real-time PCR, and the correlation between the expression of Reg IV and SOX9 was analyzed in gastric cancer tissues. Reg IV expression vectors and a siRNA of Reg IV and SOX9 were transfected into human gastric cancer cells and the protein and mRNA levels of Reg IV and SOX9 were investigated by western blot and real-time PCR. The invasion and migration ability of gastric cancer cells with overexpressed Reg IV and with gene silence of Reg IV and SOX9 were examined by transwell chambers and wound healing assay. RESULTS: The Reg IV and SOX9 protein expression levels were both significantly higher in gastric cancer tissues compared with adjacent tissues (p = 0.022, p = 0.003). Reg IV protein expression significantly correlated with tumor invasion depth (p <  0.001), but had no significant correlations with age, clinical stage or lymph node metastasis. SOX9 protein expression also had no significant correlations with age, clinical stage, tumor invasion depth or lymph node metastasis. Reg IV transcript expression demonstrated a significant correlation with invasion depth and lymph node metastasis (p = 0.005, p <  0.001) and no significant correlations with age, clinical stage, tumor tissue differentiation or tumor size. SOX9 transcript expression demonstrated a significant correlation with invasion depth and tumor tissue differentiation (p = 0.044, p = 0.007) and no significant correlations with age, clinical stage or tumor size. The Reg IV expression showed a positive correlation with the SOX9 expression (p <  0.000, p = 0.008). Overexpression of Reg IV could upregulate SOX9 expression and promote invasiveness and migration of tumor cells, and silencing of Reg IV could downregulate SOX9 and inhibit invasiveness and migration of tumor cells in MKN-45 and AGS cells. On the other hand, silencing of SOX9 could upregulate Reg IV protein expression. CONCLUSIONS: Our study demonstrated that Reg IV positively regulates the expression of SOX9 and is involved in tumor cell invasion and migration in gastric cancer.

A simple and economical strategy for obtaining calibration plots for relative quantification of positional isomers of YYX/YXY triglycerides using high-performance liquid chromatography/tandem mass spectrometry.

RATIONALE: Positional analysis of intact triglycerides could provide greater insights into the link between fatty acid position and lipotoxic diseases. However, this methodology has been impeded by lack of commercial availability of positionally pure triglycerides. This work reports on a strategy for defining calibration plots for YXY/YYX triglyceride systems based on the product ion intensities in the collision-induced dissociation spectra of ammoniated precursor ions. METHODS: A set of triglycerides were synthesized and analyzed by electrospray ionization tandem mass spectrometry using an ion trap mass spectrometer. The product ion spectra of the ammoniated precursor ions were collected for 42 triglyceride systems of the form YXY/YYX, where Y represents C16:0 , C18:1(c-9) and C20:4(cccc-5,8,11,14) . Three-point calibration plots were prepared by plotting the relative abundance of the YY+ product ion vs. the relative abundance of the YYX positional isomer. RESULTS: The calibration plots were shown to give relative abundances of positional isomers accurate to within ±0.02 for most systems. Using an ion trap, under a controlled set of collision parameters, the slopes of the calibration plots can be used to compare the sensitivities of the product ion intensities to fatty acid position for various triglyceride systems. The average slopes of the calibration plots for the C16:0 , C18:1(c-9) and C20:4(cccc-5,8,11,14) systems were 0.29 ± 0.05, 0.21 ± 0.05 and 0.045 ± 0.005, respectively. CONCLUSIONS: While the presence of multiple unsaturated fatty acids tends to slightly decrease the slopes of the calibration plots, the data suggest that the sensitivities are sufficient for performing positional analysis of most triglyceride systems. However, the presence of unsaturated fatty acids that contain double bonds close to the carbonyl group, such as arachidonic acid, tends to dramatically decrease positional sensitivity.

Ubiquitin related enzymes and plant-specific ubiquitin ligase ATL family in tomato plants.

Ubiquitination is one of the fundamental post-translational modifications of proteins with ubiquitin, a conserved 76-amino acid protein present in eukaryotes, which is catalyzed by ubiquitin ligase. Compared with humans, the number of ubiquitin ligase genes is nearly double in plant species such as Arabidopsis and rice, suggesting that this enzyme plays critical roles in many aspects of plant growth, including development and abiotic and biotic environmental stress responses. In addition to its fundamental activities in eukaryotic cells, ubiquitin signaling mediates plant specific cellular functions, including phytohormone response, seed and fruit development, and biotic and abiotic stress responses. The ATL family is a RING-H2 type ubiquitin ligase widely conserved in plant species. We previously showed that the plant specific ubiquitin ligase ATL31 regulates the carbon/nitrogen-nutrient response and pathogen resistance in Arabidopsis, and we identified and characterized the basic biochemical function of an ATL31 homologue in tomato plants (Solanum lycopersicum L.). This protein, called SlATL31, may act as a ubiquitin ligase in tomato fruit. The tomato is a major crop plant and a model system for fleshy fruit development. This review provides an overview of the ubiquitin ligases and related enzymes, and highlights the ubiquitin ligase ATL family in tomato plants.