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To investigate the characteristics of pulmonary artery distensibility (PAD) in patients with acute pulmonary embolism (APE) and to assess whether a relationship exists between PAD and the disease severity. Clinical and radiological data of 30 APE patients who underwent retrospective electrocardiogram (ECG)-gated computed tomography pulmonary angiography (CTPA) with a definite diagnosis of APE were retrospectively reviewed in the present study, including 15 subjects in severe (SPE) group and 15 subjects in non-severe (NSPE) group. PAD and cardiac function parameters were compared between the two groups, their relationships were investigated, and receiver operating characteristic (ROC) curves were used to determine the sensitivity and specificity of the above parameters for the diagnosis of APE severity. The PAD decreased in the following order: NSPE group (6.065 ± 2.114) × 10−3 (%/mmHg), and SPE group (4.334 ± 1.777) × 10−3 (%/mmHg) (P < 0.05). All the cardiac function parameters except RA/LAdiameter showed statistically significant different values between the two groups (P < 0.05). As APE severity increased, the cardiac morphological measurements of RV/LVdiameter, RV/LVarea, RVEDV/LVEDV and RVESV/LVESV increased. There was a weak to moderate negative correlation between PAD and PAmax, PAmin, PA/AAmin, PA/AAmax, RV/LVdiameter, RV/LVarea (r = −0.393 to −0.625), that is, PAD was inversely correlated with cardiac function parameters. There was a moderate negative correlation between PAD and hemoptysis(r = −0.672). The area under the ROC curve (AUC) of PAD was 0.724, the critical value was 4.137 × 10−3 mm/Hg, and the sensitivity and specificity were 60.0% and 93.3%, respectively. PAmin showed the strongest discriminatory power to identify high-risk patients (AUC = 0.827), with the highest sensitivity of 100%, which was also achieved by RA/LAarea. The PAD obtained by retrospective ECG-gated CTPA could be an indicator to be used in the evaluation of the presence and severity of APE.

Purpose The goal of this study is to develop and validate a radiomics nomogram integrating the radiomics features from DCE-MRI and clinical factors for the preoperative diagnosis of axillary lymph node (ALN) metastasis in breast cancer patients. Procedures A total of 432 patients with breast cancer were enrolled in this retrospective study and divided into a training cohort (n = 296) and a validation cohort (n = 136). Radiomics features were extracted from the second phase of dynamic contrast enhanced (DCE) MRI images. The least absolute shrinkage and selection operator (LASSO) regression method was used to screen optimal features and construct a radiomics signature in the training cohort. Multivariable logistic regression analysis was used to establish a radiomics nomogram model based on the radiomics signature and clinical factors. The predictive performance of the nomogram was quantified with respect to discrimination and calibration, which was further evaluated in the independent validation cohort. Results Fourteen ALN metastasis-related features were selected to construct the radiomics signature, with an area under the curve (AUC) of 0.847 and 0.805 in the training and validation cohorts, respectively. The nomogram was established by incorporating the histological grade, multifocality, MRI report lymph node status and radiomics signature and showed good calibration and excellent performance for ALN detection (AUC of 0.907 and 0.874 in the training and validation cohorts, respectively). The decision curve, which demonstrated the radiomics nomogram, displayed promising clinical utility. Conclusions The radiomics nomogram can be used as a noninvasive and reliable tool to assist clinicians in accurately predicting ALN metastasis in breast cancer preoperatively.

The thermal stability and structural transformation mechanism are critical for the industrial applications of zeolites and the design of new framework types. Herein, a new zeolite PKU-26 has been hydrothermally synthesized under fluoride conditions using a tetraethylammonium (TEA+ ) cation as the structure-directing agent (SDA) and its framework contains partial Q3 T atoms [Q3 for T(-O-T)3 OH]. Upon calcination, PKU-26 processed a single-crystal to single-crystal transformation to another novel zeolite PKU-27 with the elimination of terminal -OH groups and enhanced thermal stability up to 650 °C, exhibiting the first Q3 →Q4 transformation [Q4 for T(-O-T)4 ] in 3D zeolite frameworks. The mechanism of the structural transformation, involving proton transfer, framework dehydration, and TO4 reconstruction, is proposed and supported by theoretical calculations.

Mesoporous carbon materials with thin pore walls (∼1.7 nm) were synthesized using low-cost γ-Al2O3 as a hard template and in situ polymerized resorcinol–furfural resin as the carbon precursor. Compared with sugar, resin, a widely used carbon precursor, has higher carbon yield and simplifies the synthetic process. Ph-SO3H modified mesoporous carbon was synthesized by covalent grafting of Ph-SO3H groups on mesoporous carbon via the diazonium salt. The resulting materials were characterized by means of nitrogen adsorption analysis, TEM, 13C NMR, XRD, FTIR and sulfur elemental analysis. The modified carbons were shown to possess high surface area (∼1000 m2/g), a bimodal pore size distribution and high strong acid density (1.86 mmol H+/g). These sulfonated carbons were used as solid acid catalysts in the esterification of oleic acid and methanol, a key reaction in biodiesel production. Compared with the traditional solid acid Amberlyst-15, the optimized carbon catalyst exhibited much higher activity with a rate constant (1.34 h−1) three times to that of Amberlyt-15 and a turnover frequency (TOF) of 128 h−1 eight times that of Amberlyst-15. The efficient catalytic ability was attributed to the high surface area and a proper mesopore texture. This carbon catalyst could then be easily separated from the product by filtration. The catalyst was reused six times, and no distinct activity drop was observed after the initial deactivation.

Liquid phase hydrogenation of cinnamaldehyde was evaluated over SiO 2 supported Co-Pt and Cu-Pt bimetallic and Co, Cu, Pt monometallic catalysts in a batch reactor. H 2 -temperature-programmed reduction (H 2 -TPR) was utilized to characterize the reduction behavior and pulse CO chemisorption measurement was performed to characterize the number of active sites of the catalysts. Transmission electron microscopy (TEM) analysis was used to characterize metallic particle size distribution and extended X-ray absorption structure (EXAFS) measurements were performed to verify the bimetallic bond formation. The reactor evaluation results show that Co-Pt and Cu-Pt bimetallic catalysts exhibit much higher hydrogenation activity than the corresponding monometallic catalysts, and Co-Pt shows much higher selectivity toward C O bond hydrogenation than Cu-Pt. The trend of hydrogenation activity and selectivity is consistent with previous studies of the hydrogenation of unsaturated aldehydes on model bimetallic surfaces.

The phosphorous-modified TiO2 (P-TiO2) was synthesized by a hydrothermal method. The as-prepared P-TiO2 was evaluated for the degradation of methylene blue, the dechlorination of 4-chlorophenol, and the inactivation of Escherichia coli. In all these experiments, P-TiO2 shows superior activity compared with pure TiO2 and even better activity than the commercially available P25 in most cases. By carrying out methylene blue degradation in the presence of different scavengers, ·OH radicals were found to be the dominant reactive oxidizing species. The excellent performance of P-TiO2 was correlated with its pronounced ability to generate ·OH radicals under illumination. We also found that P-TiO2 is extraordinarily stable against annealing. Its transformation from anatase to rutile does not occur until calcination as high as 950 °C. This phase transformation is retarded since the phosphate species on the surface of the particles acts as a barrier to grain boundary nucleation. This peculiar feature of P-TiO2 gives it reliable performance during water decontamination even after calcination at 900 °C since it retains a 100% anatase phase at this stage.

Several TiO2 and γ-Al2O3 supported catalyst systems were prepared by a novel way and characterized by X-ray diffraction, Raman spectroscopy and BET surface area measurement. The results show: (1) all the samples, including MoO3/TiO2, WO3/TiO2, V2O5/TiO2, FeSO4/γ-Al2O3, Al2 (SO4)3/γ-Al2O3, K2CO3/-Al2O3 and so on, prepared by impregnating TiO2·H2O or pseudo-boehmite AlO(OH) with the active components then calcining at a high temperature exhibit much larger surface areas than that of pure TiO2 or γ-Al2O3 calcined at the same temperature; (2) the surface area of the sample increases with the increase in the coverage of active component on the surface of the support; (3) when the content of active component reaches its utmost monolayer dispersion capacity, the surface area of the sample is the largest, and then decreases when the content of active component exceeds its dispersion threshold.

PtCo bimetallic and Co, Pt monometallic catalysts supported on γ-Al2O3, SiO2, TiO2 and activated carbon (AC) were prepared and evaluated for the hydrogenation of benzene at relatively low temperatures (343 K) and atmospheric pressure. Results from flow reactor studies showed that supports strongly affected the catalytic properties of different bimetallic catalysts. AC supported PtCo bimetallic catalysts exhibited significantly better performance than the other bimetallic catalysts, and all the bimetallic catalysts possessed higher activity than the corresponding monometallic catalysts. Results from CO chemisorption and H2-temperature-programmed reduction (H2-TPR) studies suggested that different catalysts possessed different properties in chemisorption capacity and reduction behavior, and AC supported PtCo catalysts possessed significantly higher CO chemisorption capacity compared to the other catalysts. Extended X-ray absorption fine structure (EXAFS) and transmission electron microscopy (TEM) analysis provided additional information regarding the formation of Pt–Co bimetallic bonds and metallic particle size distribution in the PtCo bimetallic catalysts on different supports.

A series of phosphorus-doped titania samples with different phosphorus contents have been prepared by a simple, modified sol−gel method. The obtained samples were characterized by X-ray diffraction spectrometry, Brunauer−Emmett−Teller surface area, differential thermal analysis-thermogravimetry, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and UV−vis diffuse reflectance spectroscopy, and the photodegradation of methylene blue (MB) on the samples was tested under both UV and visible light irradiation. It was found that the doped phosphorus existed in a pentavalent oxidation state, replacing part of Ti4+ in the anatase lattice in the form of Ti−O−P bonds. Increased calcination temperature gave an enrichment of P species on the titania surface. The P species in the titania lattice should be the dominant group responsive to visible light, whereas the P species on the surface could retard the phase transition of anatase to rutile and increase the surface area a...

Pd/Ni bimetallic catalysts were prepared by replacement reactions, characterized by X-ray diffraction, CO chemisorption and H2 temperature-programmed desorption, and evaluated for hydrogenation of cyclohexene, styrene and acetone. The results show that Pd atoms are monolayer-dispersed on the Ni surface in these Pd/Ni catalysts. Consequently, Pd/Ni catalysts are much more active than Pd/Ni and Pd/c-Al2O3 with the same Pd loading prepared by the conventional impregnation method.

Series of bimetallic systems were prepared by replacement reactions and characterized by XRD and XPS. The results suggest that the ad-metals are monolayer dispersed on the surface of sub-metal in Pd(Pt, Cu)/Co(Ni) systems, while in Pd(Pt, Au)/Cu systems surface solid solution is formed. In Ag(Au)/Co(Ni) and Ag/Cu systems no interaction between the metals is observed just as in the simple mixture of the respective crystallites. The outermost electronic configurations, the atomic radius of the metals, and the low-preparation temperature seem to be important factors for the different states of these bimetallic catalysts.

Several Pd-based bimetallic catalysts, Pd/Co, Pd/Ni and Pd/Cu, were synthesized by replacement reactions. The catalysts were characterized by XRD and CO chemisorption and their catalytic properties were evaluated using cyclohexene self-hydrogenation. The results suggest that the high catalytic activity of Pd/Ni is most likely due to the monolayer-dispersion of Pd on the Ni surface. The results also suggest that Pd is monolayer-dispersed on the Co surface in Pd/Co, whereas Pd forms surface alloy or solid solution with Cu in Pd/Cu.

Calcining carbon-covered alumina (CCA) samples at 800°C in an oxygen flow is an efficient method to prepare α-alumina powders. It is found that the pore size distribution of CCA samples, which depends on the carbon content and the pore size distribution of the precursor alumina used, is one of the key factors for the total conversion of γ-alumina to α-alumina and the complete combustion of carbon in the pores of alumina. No matter how high the carbon content, total conversion does not occur for CCA samples prepared from alumina possessing the most probable pore size of about 5.2 nm. Using γ-alumina with the most probable pore size of 6.1 nm as the precursor of CCA samples, total transformation occurs when the carbon content of CCA ranges from 11.9 to 17.3 wt%, but the color of as-prepared α-alumina is not pure white but light gray. Polyethylene glycol (PEG 20 000), added to the sucrose/γ-alumina system, can expand the pores of CCA samples after carbonization, and calcining of thus-prepared CCA results in a complete transformation of γ-alumina to pure white α-alumina with a particle size of about 1 μm when the carbon content of CCA is between 6 and 19 wt%.

Three kinds of MgC 2 O 4 ·2H 2 O were prepared by the precipitation method with different raw materials, and MgO with high surface area was obtained via thermal decomposition of MgC 2 O 4 ·2H 2 O in different atmospheres. The precursor MgC 2 O 4 ·2H 2 O and as-prepared MgO were characterized by XRD, BET, TEM, and TG-DTA measurements. It was found that using Mg(CH 3 COO) 2 ·4H 2 O and H 2 C 2 O 4 ·2H 2 O as the starting materials and calcining the precursor MgC 2 O 4 ·2H 2 O in flowing dry gas are the key factors to obtain high surface area for MgO. The MgO prepared at the optimum condition is composed of nanocrystals with a size of about 4–5 nm and forms a wormhole-like porous structure with a specific surface area of 534 m 2 ·g −1 after calcining at 520 °C. In addition, the MgO has good thermal stability; after being calcined at 650 °C and 800 °C for 2 h, its surface area is still 229 m 2 ·g −1 and 134 m 2 ·g −1 , respectively.

Ni(II)/Ti(IV) layered double hydroxide (LDH) was synthesized by homogeneous precipitation method utilizing urea hydrolysis. The structure and composition of the LDHs were characterized by PXRD, FT-IR, ICP-AES, SEM, nitrogen adsorption/desorption isotherms, TG-DTA, and in situ high temperature X-ray diffraction techniques. It was found that Ti4+ cation are incorporated in the host layers with cyanate anion as the interlayer anions. The titanium content incorporated in the LDH slabs increases with prolonged synthesis time. The Ni–Ti-LDH crystallinity decreases with increasing Ti4+ dosage in the synthesis mixture. No extra-framework titanium species was observed existing in the Ni–Ti-LDH. Both the surface area (182 m2/g) and pore volume (0.86 cm3/g) for the LDH synthesized using the urea method are higher than that by conventional methods. The Ni–Ti-LDH is converted to Ni–Ti-LDO above 473 K.

Novel catalysts, SnxZr1-xO2 solid solutions, for NO selective catalytic reduction:NO SCR) are reported. They have much higher activity and selectivity than SnO2 and ZrO2. Sn4+ is the main reductive sites as proved by TPR. The dilution of Sn sites by the coexisting Zr causes a suppression of propene combustion and consequently promoted the selective reduction of NO. The rutile structure might be beneficial to NO SCR.

Si-doped and rare earth-doped TiO2 with large specific surface area were prepared by the hydrothermal method and sol–gel route, respectively, using C18H37NH2 as template. The samples were characterized by XRD, FT-IR, low-temperature N2 adsorption–desorption measurement, XPS and solid state UV–vis diffuse reflectance spectroscopy. The pore size for Si-doped TiO2 exhibits both mesoporous and microporous distribution, and that for rare earth-doped TiO2 exhibits a sharp and narrow distribution in microporous range. The photocatalytic activities were investigated with the degradation of phenol as probe reaction. Compared with pure TiO2, the conversion of phenol and selectivity to CO2 increases when adding rare earth elements, and the substitution of Si for Ti in an appropriate range also increases the conversion of phenol.

A novel catalyst, Pd supported on TiO2/Al2O3 has been investigated for the total oxidation of methane. Static reaction between CH4 and 18 O 2 in the presence of catalyst was performed to investigate the reaction pathway and a redox mechanism with Pd-PdO as the active species was suggested. The TPR and 18 O -isotope exchange experiments were carried out to characterize the catalysts to reveal the key factors influencing the activity. It was shown that addition of titania into alumina enhanced the reduction as well as the oxygen mobility of palladium oxide and thus generated catalyst with much higher activity for the reaction. It was also found that the existence of residual chlorine ions on the catalyst surface would lower the oxygen mobility and reducibility of the supported palladium oxide and consequently inhibit the activity of the catalyst for methane total oxidation.

A series of Sn-Cr binary oxide catalysts were prepared by a co-current co-precipitation method and tested for methane total oxidation. The binary oxide catalysts have much higher surface areas and catalytic activities for methane oxidation than pure SnO2. CrO x /SnO2 with a Cr/Sn atomic ratio of 3:7 displays the highest activity. Selected samples were subjected to temperature-programmed 18O isotope-exchange measurements. Both complete and partial heteromolecular 18O isotope exchange, as well as oxygen release, was observed for all catalysts. Reaction between CH4 and 18O2 under static conditions was performed to investigate the reaction mechanism and it was found that the total oxidation of methane over Sn-Cr binary oxide catalysts occurs via a redox cycle with the chromium ion in a high oxidation state as the active center. Oxygen mobility of the catalyst plays an important role in the total oxidation of methane, but too high a mobility leads to very high oxygen release and a reduction of the surface reoxidability. This causes a decrease in the catalytic oxidation activity.

The monolayer-dispersed Pt/Ni bimetallic catalyst was prepared through a simple replacement reaction, and its catalytic activity for the hydrogenation of cyclohexene, styrene, acetone, and butyl aldehyde was also tested. The Pt/Ni catalyst that was prepared by the replacement reaction showed much higher activity than Pt/Ni and Pt/Al 2 O 3 catalysts with the same Pt loading prepared by the conventional impregnation method.

SnO2-ZrO2 binary oxide solid solution was found to be a novel and good catalytic system for the selective reduction of NO by propene in the presence of oxygen. The NO conversion over SnO2-ZrO2 binary oxides changed with SnO2 content, and was the highest at about 60wt% SnO2. At 350°C, 77% conversion of NO to N2 was obtained for a feed of He stream with 1186ppm NO, 948ppm propene and 2.23% O2 at a space velocity of 15,000h−1. XRD analysis showed that uniform solid solutions with cassiterite phase were found for the SnO2 rich Sn1−xZrxO2 samples, while monoclinic and tetragonal ZrO2 phases were formed for the ZrO2 rich samples. TPR measurements suggest the introduction of Zr ions into SnO2 lattice can lead to the decease of hydrocarbon oxidation capacity and the formation of new easier reduction oxygen, which may be beneficial to the reactivity enhancement of NO conversion. The sample with composition in the intersection point of the two kinds of solid solutions (Sn0.55Zr0.45O2) presented as an amorphous phase and showed the highest activity. The solid solution catalysts could sustain moderate activity after a calcination at 800°C, in the presence of high O2 partial pressure or in the presence of 10% water.

Spontaneous monolayer dispersion of oxides and salts onto supports is quite a widespread phenomenon and an important principle for the preparation and design of heterogeneous catalysts. This paper summarizes the main results developed in our laboratory. It contains the following points: (1) Preparation of highly active catalysts by dispersing active components on supports as a monolayer. (2) Thermal dispersion of active components onto supports as monolayer can be a simple method to make some catalysts. (3) Monolayer-dispersed oxides or salts play a role as surface modifiers. (4) Monolayer-dispersed oxides or salts on supports are better precursors of supported metal catalysts. (5) Regeneration of supported metal catalysts based on spontaneous monolayer dispersion of oxide and salt of the metals. (6) Hindering sinter of supports with monolayer-dispersed oxide or salt to make catalysts with very high surface area. (7) Modification of zeolites by spontaneous dispersion of oxides or salts to zeolites.

Temperature programmed reduction of Pd/MnO 2 and Pd/Fe 2 O 3 systems were investigated. The results show that the presence of Pd lowers the reduction temperature of MnO 2 and Fe 2 O 3 due to hydrogen spillover from Pd to the oxides. Thus developed oxygen getter Pd/MnO 2 can be regenerated at lower temperature and can absorb more oxygen at room temperature than the traditional oxygen getter.

The hydrogenation of propanal is used as a probe reaction to correlate the activity of CO bond hydrogenation over Ni–Pt bimetallic surfaces and catalysts. Density functional theory (DFT) calculations predict that propanal is more weakly bonded on the Pt–Ni–Pt(111) subsurface structure than on either Ni or Pt, suggesting a possible novel low-temperature hydrogenation pathway based on a previous trend predicted for CC hydrogenation. Surface science studies using temperature programmed desorption (TPD) on Ni-modified polycrystalline Pt foil verify that different bimetallic surface structures exhibit distinct CO hydrogenation activity, with the Pt–Ni–Pt subsurface structure being much more active for propanal hydrogenation. Furthermore, γ-Al2O3 supported Ni–Pt bimetallic catalysts have been prepared to extend the surface science studies to real world catalysis. In the gas phase hydrogenation of propanal, both batch and flow reactor studies show that Ni–Pt/γ-Al2O3 bimetallic catalysts exhibit enhanced CO hydrogenation activity compared to the corresponding monometallic catalysts. The excellent correlation between theoretical predictions, surface science studies on model surfaces, and catalytic evaluation of supported catalysts demonstrates the feasibility to rationally design bimetallic catalysts with enhanced hydrogenation activity.