Bottom-up Growth of Convex Sphere with Adjustable Cu(0)/Cu(I) Interfaces for Effective C2 Production from CO2 Electroreduction.

One challenge confronting the Cu2O catalysts in the electrocatalysis of carbon dioxide reduction reaction (CO2RR) is the reduction of active Cu(I) species, resulting in low selectivity and quick deactivation. In this study, we for the first time introduce a bottom-up growth of convex sphere with adjustable Cu(0)/Cu(I) interfaces (Cux@Cu2O convex spheres). Interestingly, the interfaces are dynamically modulated by varying hydrothermal time, thus regulating the conversion of C1 and C2 products. In particular, the 4 h hydrothermal treatment applied to Cu0.25@Cu2O convex sphere with the favorable Cu(0)/Cu(I) interface results in the highest selectivity for C2 products (90.5 %). In situ Fourier-transform infrared spectroscopy measurements and density functional theory calculations reveal that the Cu(0)/Cu(I) interface lowers the energy barrier for the production of ethylene and ethanol while increasing the coverage of localized *CO adsorbate for increased dimerization. This work establishes a novel approach for transforming the state of valence-sensitive electrocatalysts into high-value energy-related engineering products.

Interface Engineering in 2D/2D Heterogeneous Photocatalysts.

Assembling different 2D nanomaterials into heterostructures with strong interfacial interactions presents a promising approach for novel artificial photocatalytic materials. Chemically implementing the 2D nanomaterials' construction/stacking modes to regulate different interfaces can extend their functionalities and achieve good performance. Herein, based on different fundamental principles and photochemical processes, multiple construction modes (e.g., face-to-face, edge-to-face, interface-to-face, edge-to-edge) are overviewed systematically with emphasis on the relationships between their interfacial characteristics (e.g., point, linear, planar), synthetic strategies (e.g., in situ growth, ex situ assembly), and enhanced applications to achieve precise regulation. Meanwhile, recent efforts for enhancing photocatalytic performances of 2D/2D heterostructures are summarized from the critical factors of enhancing visible light absorption, accelerating charge transfer/separation, and introducing novel active sites. Notably, the crucial roles of surface defects, cocatalysts, and surface modification for photocatalytic performance optimization of 2D/2D heterostructures are also discussed based on the synergistic effect of optimization engineering and heterogeneous interfaces. Finally, perspectives and challenges are proposed to emphasize future opportunities for expanding 2D/2D heterostructures for photocatalysis.

SO2- and H2O-Tolerant Catalytic Reduction of NOx at a Low Temperature via Engineering Polymeric VOx Species by CeO2.

Selective catalytic reduction (SCR) of NOx over V2O5-based oxide catalysts has been widely used, but it is still a challenge to efficiently reduce NOx at low temperatures under SO2 and H2O co-existence. Herein, SO2- and H2O-tolerant catalytic reduction of NOx at a low temperature has been originally demonstrated via engineering polymeric VOx species by CeO2. The polymeric VOx species were tactfully engineered on Ce-V2O5 composite active sites via the surface occupation effect of Ce, and the obtained catalysts exhibited remarkable low-temperature activity and strong SO2 and H2O tolerance at 250 °C. The strong interaction between Ce and V species induced the electron transfer from V to Ce and tuned the SCR reaction via the E-R pathway between the NH4+/NH3 species and gaseous NO. In the presence of SO2 and H2O, the polymeric VOx species had not been hardly influenced, while the formation of sulfate species on Ce sites not only promoted the adsorption of NH4+ species and the reaction between gaseous NO and NH4+ but also facilitated the decomposition of ammonium bisulfate through weakening the strong bond between HSO4- and NH4+. This work provided a new strategy for SO2- and H2O-tolerant catalytic reduction of NOx at a low temperature.

Associations between prepregnancy body mass index, gestational weight gain, and pregnancy outcomes in women with twin pregnancies: A five-year prospective study.

BACKGROUND: The purpose of this project was to investigate the relationship between prepregnancy body mass index (ppBMI), gestational weight gain (GWG), and pregnancy outcomes in women with twin pregnancies. METHODS: A prospective cohort of 369 women with dichorionic diamniotic twin pregnancies was recruited from 2016 to 2020. According to ppBMI using Chinese BMI classifications, they were categorized into the underweight (BMI < 18.5 kg/m2 ), normal (BMI 18.5-23.9 kg/m2 ), and overweight and obese (BMI ≥ 24 kg/m2 ) groups. In each ppBMI group, they were divided into two subgroups based on the presence or absence of the complications such as gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy (HDP), and small for gestational age (SGA). The outcomes including GDM, HDP, and SGA were compared among three ppBMI groups, and the associations of GWG with these outcomes within each ppBMI category were analyzed. RESULTS: Twin-pregnant women with overweight and obesity were at increased risks of HDP (aOR = 4.417 [95% CI = 1.826-9.415]) and SGA (2.288 [1.102-4.751]), whereas underweight women were prone to deliver SGA newborns (2.466 [1.157-5.254]). Women with GDM gained less weight during pregnancy than those without GDM within each ppBMI category. For overweight and obese women, greater GWG increased the incidence of HDP (1.235 [1.016-1.500]) and decreased the risk of SGA (0.818 [0.702-0.953]). CONCLUSIONS: Both ppBMI and GWG in twin-pregnant women were strongly associated with HDP and SGA, but not GDM.

Photoelectrochemical Reduction of Carbon Dioxide with a Copper Graphitic Carbon Nitride Photocathode.

Research on the photoreduction of CO2 often has been dominated by the use of sacrificial reducing agents. A pathway that avoids this problem would be the development of photocathodes for CO2 reduction that could then be coupled to a photoanodic oxygen evolution reaction. Here, we present the use of copper-substituted graphitic carbon nitride (Cu-CN) on a fluorinated tin oxide (FTO) electrode for the photoelectrochemical two-electron reduction of CO2 to CO as a major product (>95 %) and formic acid (<5 %). The results show that at a potential of -2.5 V versus Fc\Fc+ the CO2 reduction activity of Cu-CN on FTO electrode improves by 25 % upon illumination by visible light with a faradaic efficiency of nearly 100 %. Independently, X-ray photoelectron spectroscopy conclusively shows a pronounced increase in the electrical conductivity of the Cu-CN upon white light illumination under vacuum and a contactless measuring configuration. This photo-assisted charge mobility is shown to play a key role in the increased reactivity and faradaic efficiency for the reduction of CO2 .

The association of antenatal D-dimer and fibrinogen with postpartum hemorrhage and intrauterine growth restriction in preeclampsia.

BACKGROUND: D-dimer and fibrinogen were verified to be altered in preeclampsia. This study was to evaluate the associations of D-dimer and fibrinogen plasma levels with postpartum hemorrhage or intrauterine growth restriction in preeclamptic women. METHODS: This was a retrospective study that recruited 278 preeclamptic women with singleton pregnancy from January 2016 to December 2019. Patients were allocated into five groups: mild preeclampsia (mPE) (n=68), mild preeclampsia with postpartum hemorrhage (mPE+PPH) (n=13), severe preeclampsia (sPE) (n=112), severe preeclampsia with postpartum hemorrhage (sPE+PPH) (n=17) and severe preeclampsia with intrauterine growth restriction (sPE+IUGR) (n=68). The antenatal D-dimer and fibrinogen plasma levels were analyzed among the groups. Logistic regression was used to determine the correlation between serum indexes and PPH or IUGR in preeclampsia. RESULTS: The antenatal D-dimer plasma levels were significantly higher in the sPE+PPH group than that in the sPE group (2.02 µg/ml versus 1.37 µg/ml, P = 0.001), but there was no difference in fibrinogen. Elevated D-dimer was associated with PPH among severe preeclamptic women (adjusted odds ratio (aOR) [95% CI]: 3.093 [1.527-6.264], P = 0.002). No differences in D-dimer and fibrinogen were found between the mPE and mPE+PPH groups or between the sPE and sPE+IUGR groups. CONCLUSIONS: Elevated antenatal plasma D-dimer level may be associated with postpartum hemorrhage in severe preeclampsia, but not with intrauterine growth restriction. Future prospective clinical trials are needed to investigate the predictive value of D-dimer in postpartum hemorrhage in severe preeclampsia.

Graphene-Based Biosensors with High Sensitivity for Detection of Ovarian Cancer Cells.

Ovarian cancer has the highest mortality rate in the world. Therefore, it is urgent but still challenging to develop an efficient circulating tumor cell (CTC) detection method to sensitively detect ovarian cancer. To address such issues, herein, for the first time, we present a novel CTC detection method for ovarian cancer cells by designing sensitive and rapid graphene-based biosensors. This graphene-based sensor, consisting of a cell pool and two electrodes, can be prepared by a conventional chip fabrication process. It demonstrates high-sensitivity detection even for several ovarian cancer cells by comparing the electrical signal before and after adding cell solution. Moreover, the graphene-based biosensors can perform rapid detection with good repeatability. This suggests that this novel method is possible to use for the early detection of ovarian cancer with very low CTC cell concentration. This work provides a novel and quick strategy to detect ovarian cancer and further judge or predict the risk of the transfer of ovarian cancer.

Design of a shim coil array matched to the human brain anatomy.

PURPOSE: The purpose of this study is to introduce a novel design method of a shim coil array specifically optimized for whole brain shimming and to compare the performance of the resulting coils to conventional spherical harmonic shimming. METHODS: The proposed design approach is based on the stream function method and singular value decomposition. Eighty-four field maps from 12 volunteers measured in seven different head positions were used during the design process. The cross validation technique was applied to find an optimal number of coil elements in the array. Additional 42 field maps from 6 further volunteers were used for an independent validation. A bootstrapping technique was used to estimate the required population size to achieve a stable coil design. RESULTS: Shimming using 12 and 24 coil elements outperforms fourth- and fifth-order spherical harmonic shimming for all measured field maps, respectively. Coil elements show novel coil layouts compared to the conventional spherical harmonic coils and existing multi-coils. Both leave-one-out and independent validation demonstrate the generalization ability of the designed arrays. The bootstrapping analysis predicts that field maps from approximately 140 subjects need to be acquired to arrive at a stable design. CONCLUSIONS: The results demonstrate the validity of the proposed method to design a shim coil array matched to the human brain anatomy, which naturally satisfies the laws of electrodynamics. The design method may also be applied to develop new shim coil arrays matched to other human organs.

The Predictive Value of Red Cell Distribution Width and Red Cell Distribution Width to Erythrocyte Count Ratio for Adverse Cardiovascular Events During the Hospitalization of Patients of ST-segment Elevation Myocardial Infarction.

BACKGROUND: High red cell distribution width (RDW) is correlated with poor prognosis in acute coronary syndromes (ACS), including ST-segment elevation myocardial infarction (STEMI). However, the association of red cell distribution width to erythrocyte count ratio (RER) with STEMI undergoing percutaneous coronary intervention (PCI) during hospitalization has not been investigated. Therefore, we performed a retrospective study to investigate whether RER is associated with STEMI patients after PCI during hospitalization. METHODS: A total of 331 patients, who were hospitalized for STEMI and underwent PCI, were enrolled. Receiver operating characteristic curve (ROC) analyses were used to find the cutoff value of RER and classify the patients into two groups including higher RER group and lower RER group by cutoff value. Differences between measured parameters in higher RER and lower RER groups were analyzed by the Mann-Whitney U test. The evaluation correlation of RDW, red blood cell, and RER with major adverse cardiovascular events was determined by bivariate regression analysis. Univariate logistic regression analysis was used to determine the factors associated with adverse cardiovascular events during the hospitalization of STEMI patients. Multivariate logistic regression analysis was performed to evaluate the potential independent predictors of STEMI. RESULTS: According to ROC analysis, the cutoff value of RER and RDW is 3.10 and 13.9, the sensitivity is 51% and 35%, the specificity is 76% and 80%, respectively. RER showed improved diagnostic capacity compared to RDW in correlation with adverse cardiovascular events during hospitalization in STEMI patients (p < 0.001). Compared with the lower RER group, the incidence of adverse cardiovascular events in STEMI patients is elevated in the higher RER group (75% vs. 64.5%, p < 0.05). Bivariate regression analysis indicated that RER and RDW showed a good correlation with adverse cardiovascular events, and the difference was statistically significant (R = 0.10 p < 0.05 vs. R = 0.05 p < 0.05). Univariate logistic regression analysis showed that age, heart rate, left ventricular ejection fraction, hyperlipidemia, RDW, mean platelet volume, total cholesterol, and RER were correlated with the occurrence of adverse cardiovascular events during the hospitalization of STEMI patients (p < 0.05). Multivariate logistic regression analysis demonstrated that RER could be an independent predictor of adverse cardiovascular events in STEMI patients (B: 0.574, OR: 1.776, 95% CI: 1.043 ~ 3.023, p < 0.05). CONCLUSIONS: RER and RDW demonstrated good correlation with adverse cardiovascular events during hospitalization in STEMI patients. RER is a potential independent predictor of adverse cardiovascular events during hospitalization in STEMI patients.

A Potential Serum Biomarker, Albumin-to-Glutamyltransferase Ratio, Suggests the Severity of Liver Disease.

BACKGROUND: We aimed to investigate the utility of albumin-to-glutamyltransferase ratio (AGR) as a new biomarker to distinguish hepatic carcinoma from hepatitis, as early disease diagnosis, prognosis or monitoring could improve patient management and outcomes. METHODS: Clinical characteristics of 34 hepatitis (women 19), 88 cirrhosis (women 22) and 52 hepatic carcinoma (women 9) cases were retrospectively reviewed. Patients diagnosed with cirrhosis were classified by Child-Pugh score and the presence of ascites. The differences among groups were evaluated by the Kruskal-Wallis test and Mann-Whitney U. The linear correlation between variables was assessed by Spearman's correlation analysis. The diagnostic value of albumin-to-glutamyltransferase (AGR) was considered using receiver operating characteristic (ROC) curves. Multiple logistic regression analysis and univariate logistic regression analysis were used to identify AGR as an independent predictor in liver disease progression. RESULTS: The significant differences among the hepatitis vs. cirrhosis vs. and hepatic carcinoma were AST (108.50 ± 184.00 vs. 38.00 ± 21.50 vs. 47.00 ± 71.00, p < 0.01), TP/AST (TAR, 0.67 ± 0.69 vs. 1.77 ± 0.87 vs. 1.36 ± 0.95, p < 0.01), and ALB/GGT (AGR, 0.32 ± 0.27 vs. 0.67 ± 0.43 vs. 0.20 ± 0.26, p < 0.05). At the same time, AST (32.00 ± 13.50 vs. 53.00 ± 23.00 vs. 114.50 ± 42.50, p < 0.05) and TAR (2.15 ± 0.72 vs. 1.28 ± 0.74 vs. 0.64 ± 0.39, p < 0.05) were higher but AGR (0.86 ± 0.54 vs. 0.46 ± 0.32 vs. 0.26 ± 0.22, p < 0.05) was lower in Child-Pugh class C group compared with group B and C. TAR (1.92 ± 0.73 vs. 0.98 ± 0.89, p < 0.01) and AGR (0.79 ± 0.52 vs. 0.46 ± 0.28, p < 0.05) were significantly elevated in the serum of cirrhosis with no ascites compared with the cirrhosis patients suffered from ascites, while AST (35.00 ± 14.50 vs. 63.00 ± 44.50, p < 0.01) was reduced in cirrhosis patients with no ascites. Furthermore, AST (r = 0.4490, p<0.01) was positively correlated with AFP, TAR (r = -0.4393, p < 0.01) and AGR (r = -0.4395, p < 0.01) were negatively correlated with AFP. The ROC curve analysis for AST had an area under the curve (AUC) ranging from 0.66 to 0.82, TAR ranged from 0.64 to 0.80 and AGR ranged from 0.54 to 0.72. Multiple logistic regression analysis revealed AGR as an independent parameter to distinguish liver can¬cer to hepatitis, and AGR was associated with the presence of ascites and the progression in cirrhosis patients. CONCLUSIONS: AGR is a potential biomarker for diagnosis of liver disease progression.

Evaluation of Procalcitonin and C-reactive Protein in Early Differential Diagnosis of Neonatal Jaundice.

BACKGROUND: The purpose of this study was to investigate the clinical value of procalcitonin (PCT) and C-reactive protein (CRP) in the differential diagnosis of neonatal jaundice. METHODS: Eighty-five cases of neonatal jaundice in our hospital from January 2016 to March 2019 were selected as research subjects, including 30 cases of physiological jaundice, 23 cases of infectious jaundice, and 32 cases of he-molytic jaundice. Five milliliters of non-anticoagulated venous peripheral blood and 3 mL EDTA-K+ anticoagulated venous peripheral blood were sampled from each newborn when the symptoms of jaundice occurred. The non-anticoagulated blood samples were then centrifuged at 3,500 rpm for 7 minutes and the serum was used for PCT and bilirubin examinations, and the anticoagulated blood samples were prepared for CRP examination. Receiver operating characteristic (ROC) curve analysis was performed for the evaluation of differential diagnosis of neonatal jaundice by PCT, CRP, and bilirubin levels. RESULTS: Analyses of variance showed the postnatal age of jaundice occurring in the physiological jaundice group was older than those in the infectious jaundice and hemolytic jaundice groups (p < 0.001), and the PCT and CRP levels in the infectious jaundice group were higher than those in the hemolytic jaundice and physiological jaundice groups (p < 0.001). Pearson's correlation analysis indicated that the levels of PCT and CRP were negatively correlated with postnatal age in the physiological jaundice group (p < 0.05). ROC curve analysis demonstrated that PCT and CRP had the highest differential diagnosis efficacy of neonatal pathological and neonatal physiological jaundice with PCT and CRP at 0.70 µg/L and 8.50 mg/L, respectively, as well as the highest differential diagnosis efficacy of neonatal infectious jaundice and neonatal hemolytic jaundice with PCT and CRP at 1.84 µg/L and 13.50 mg/L, respectively. CONCLUSIONS: This study suggested that PCT and CRP possessed important clinical values in the differential diagnosis of neonatal jaundice, and PCT was superior to the differential diagnosis of neonatal infectious jaundice.

Impacts of Residual Stress on Micro Vibratory Platform Used for Inertial Sensor Calibration.

A micro vibratory platform driven by converse piezoelectric effects is a promising in-situ recalibration platform to eliminate the influence of bias and scale factor drift caused by long-term storage of micro-electro-mechanical system (MEMS) inertial sensors. The calibration accuracy is critically determined by the stable and repeatable vibration of platform, and it is unavoidably impacted by the residual stress of micro structures and lead zirconate titanate (PZT) hysteresis. The abnormal phenomenon of the observed displacement response in experiments was investigated analytically using the stiffness model of beams and hysteresis model of piezoelectric material. Rather than the hysteresis, the initial deflection formed by the residual stress of the beam was identified as the main cause of the response error around the zero position. This conclusion provides guidelines to improve the performance and control of micro vibratory platforms.

Visible-Light Photochemical Reduction of CO2 to CO Coupled to Hydrocarbon Dehydrogenation.

Research on the photochemical reduction of CO2 , initiated already 40 years ago, has with few exceptions been performed by using amines as sacrificial reductants. Hydrocarbons are high-volume chemicals whose dehydrogenation is of interest, so the coupling of a CO2 photoreduction to a hydrocarbon-photodehydrogenation reaction seems a worthwhile concept to explore. A three-component construct was prepared including graphitic carbon nitride (g-CN) as a visible-light photoactive semiconductor, a polyoxometalate (POM) that functions as an electron acceptor to improve hole-electron charge separation, and an electron donor to a rhenium-based CO2 reduction catalyst. Upon photoactivation of g-CN, a cascade is initiated by dehydrogenation of hydrocarbons coupled to the reduction of the polyoxometalate. Visible-light photoexcitation of the reduced polyoxometalate enables electron transfer to the rhenium-based catalyst active for the selective reduction of CO2 to CO. The construct was characterized by zeta potential, IR spectroscopy, thermogravimetry, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). An experimental Z-scheme diagram is presented based on electrochemical measurements and UV/Vis spectroscopy. The conceptual advance should promote study into more active systems.

Development and implementation of an 84-channel matrix gradient coil.

PURPOSE: Design, implement, integrate, and characterize a customized coil system that allows for generating spatial encoding magnetic fields (SEMs) in a highly-flexible fashion. METHODS: A gradient coil with a high number of individual elements was designed. Dimensions of the coil were chosen to mimic a whole-body gradient system, scaled down to a head insert. Mechanical shape and wire layout of each element were optimized to increase the local gradient strength while minimizing eddy current effects and simultaneously considering manufacturing constraints. RESULTS: Resulting wire layout and mechanical design is presented. A prototype matrix gradient coil with 12 × 7 = 84 elements consisting of two element types was realized and characterized. Measured eddy currents are <1% of the original field. The coil is shown to be capable of creating nonlinear, and linear SEMs. In a DSV of 0.22 m gradient strengths between 24 mT∕m and 78 mT∕m could be realized locally with maximum currents of 150 A. Initial proof-of-concept imaging experiments using linear and nonlinear encoding fields are demonstrated. CONCLUSION: A shielded matrix gradient coil setup capable of generating encoding fields in a highly-flexible manner was designed and implemented. The presented setup is expected to serve as a basis for validating novel imaging techniques that rely on nonlinear spatial encoding fields. Magn Reson Med 79:1181-1191, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Structural Designing of a MEMS Capacitive Accelerometer for Low Temperature Coefficient and High Linearity.

The low temperature coefficient and high linearity of the input-output characteristics are both required for high-performance microelectromechanical systems (MEMS) capacitive accelerometers. In this work, a structural designing of a bulk MEMS capacitive accelerometer is developed for both low temperature coefficient and high linearity. Firstly, the contrary effect of the wide-narrow gaps ratio (WNGR) on the temperature coefficient of the scale factor (TCSF) and linearity error is discussed. Secondly, the ability of an improved structure that can avoid the contrary effect is illustrated. The improved structure is proposed in our previous work for reducing the temperature coefficient of bias (TCB) and TCSF. Within the improved structure, both the TCSF and linearity error decrease with increasing WNGR. Then, the precise designing of the improved structure is developed for achieving lower TCB, TCSF, and linearity error. Finally, the precise structural designing is experimentally verified.

Pulseq: A rapid and hardware-independent pulse sequence prototyping framework.

PURPOSE: Implementing new magnetic resonance experiments, or sequences, often involves extensive programming on vendor-specific platforms, which can be time consuming and costly. This situation is exacerbated when research sequences need to be implemented on several platforms simultaneously, for example, at different field strengths. This work presents an alternative programming environment that is hardware-independent, open-source, and promotes rapid sequence prototyping. METHODS: A novel file format is described to efficiently store the hardware events and timing information required for an MR pulse sequence. Platform-dependent interpreter modules convert the file to appropriate instructions to run the sequence on MR hardware. Sequences can be designed in high-level languages, such as MATLAB, or with a graphical interface. Spin physics simulation tools are incorporated into the framework, allowing for comparison between real and virtual experiments. RESULTS: Minimal effort is required to implement relatively advanced sequences using the tools provided. Sequences are executed on three different MR platforms, demonstrating the flexibility of the approach. CONCLUSION: A high-level, flexible and hardware-independent approach to sequence programming is ideal for the rapid development of new sequences. The framework is currently not suitable for large patient studies or routine scanning although this would be possible with deeper integration into existing workflows. Magn Reson Med 77:1544-1552, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

α-Catenin is an inhibitor of transcription.

α-Catenin (α-cat) is an actin-binding protein required for cell-cell cohesion. Although this adhesive function for α-cat is well appreciated, cells contain a substantial amount of nonjunctional α-cat that may be used for other functions. We show that α-cat is a nuclear protein that can interact with ß-catenin (ß-cat) and T-cell factor (TCF) and that the nuclear accumulation of α-cat depends on ß-cat. Using overexpression, knockdown, and chromatin immunoprecipitation approaches, we show that α-cat attenuates Wnt/ß-cat-responsive genes in a manner that is downstream of ß-cat/TCF loading on promoters. Both ß-cat- and actin-binding domains of α-cat are required to inhibit Wnt signaling. A nuclear-targeted form of α-cat induces the formation of nuclear filamentous actin, whereas cells lacking α-cat show altered nuclear actin properties. Formation of nuclear actin filaments correlates with reduced RNA synthesis and altered chromatin organization. Conversely, nuclear extracts made from cells lacking α-cat show enhanced general transcription in vitro, an activity that can be partially rescued by restoring the C-terminal actin-binding region of α-cat. These data demonstrate that α-cat may limit gene expression by affecting nuclear actin organization.

Trajectory optimization based on the signal-to-noise ratio for spatial encoding with nonlinear encoding fields.

PURPOSE: Multiple nonlinear gradient fields offer many potential benefits for spatial encoding including reduced acquisition time, fewer artefacts and region-specific imaging, although designing a suitable trajectory for such a setup is difficult. This work aims to optimize encoding trajectories for multiple nonlinear gradient fields based on the image signal-to-noise ratio. THEORY AND METHODS: Image signal-to-noise ratio is directly linked to the covariance of the reconstructed pixels, which can be calculated recursively for each projection of the trajectory under a Bayesian formulation. An evolutionary algorithm is used to find the higher-dimensional projections that minimize the pixel covariance, incorporating receive coil profiles, intravoxel dephasing, and reconstruction regularization. The resulting trajectories are tested through simulations and experiments. RESULTS: The optimized trajectories produce images with higher resolution and fewer artefacts compared with traditional approaches, particularly for high undersampling. However, higher-dimensional projection experiments strongly depend on accurate hardware and calibration. CONCLUSION: Computer-based optimization provides an efficient means to explore the large trajectory space created by the use of multiple nonlinear encoding fields. The optimization framework, as presented here, is necessary to fully exploit the advantages of nonlinear fields. Magn Reson Med 76:104-117, 2016. © 2015 Wiley Periodicals, Inc.

Performance evaluation of matrix gradient coils.

OBJECTIVE: In this paper, we present a new performance measure of a matrix coil (also known as multi-coil) from the perspective of efficient, local, non-linear encoding without explicitly considering target encoding fields. MATERIALS AND METHODS: An optimization problem based on a joint optimization for the non-linear encoding fields is formulated. Based on the derived objective function, a figure of merit of a matrix coil is defined, which is a generalization of a previously known resistive figure of merit for traditional gradient coils. RESULTS: A cylindrical matrix coil design with a high number of elements is used to illustrate the proposed performance measure. The results are analyzed to reveal novel features of matrix coil designs, which allowed us to optimize coil parameters, such as number of coil elements. A comparison to a scaled, existing multi-coil is also provided to demonstrate the use of the proposed performance parameter. CONCLUSIONS: The assessment of a matrix gradient coil profits from using a single performance parameter that takes the local encoding performance of the coil into account in relation to the dissipated power.

Adenovirus-mediated co-expression of ING4 and PTEN cooperatively enhances their antitumor activity in human hepatocellular carcinoma cells.

Both inhibitor of growth 4 (ING4) and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) are well known as tumor suppressors that are closely related to tumor occurrence and progression. It was reported that ING4 and PTEN showed synergistic antitumor activities in nasopharyngeal carcinoma cells. The two tumor suppressors demonstrated synergistic effect on growth inhibition and apoptosis activation. In this study, we investigated their therapeutic potential in hepatocellular carcinoma (HCC) cells. Recombinant adenoviruses co-expressing ING4 and PTEN (Ad-ING4-PTEN) were constructed, and the antitumor effect on SMMC-7721 and HepG2 HCC cells was evaluated. Ad-ING4-PTEN cooperatively inhibited cell growth, stimulated apoptosis, and suppressed invasion in both HCC cells, and regulated cell cycle in SMMC-7721. Further studies showed that the combination of ING4 and PTEN by Ad-ING4-PTEN cooperatively enhanced the alteration of the expression of cell cycle-related proteins (p53, p21, and cyclin D1) and apoptotic factors (Bad, Bcl-2, Bcl-XL, and Bax), which are involved in the regulation of cell cycle and the activation of apoptotic pathways, leading to the synergistic antitumor effect. These results indicate that the combination of ING4 and PTEN may provide an effective therapeutic strategy for HCC.