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To evaluate the efficacy and safety of TAE/TACE versus emergency surgery (ES) for spontaneous rupture of HCC (rHCC). Eight databases (Web of Science, Pubmed, Embase, Cochrane Library, ClinicalTrial.gov, Wanfang, CNKI and VIP) were searched to obtain all related literature from the inception dates to October 2019. Subgroup analyses based on the kind of study design and kind of embolization were conducted. Twenty-one studies comparing TAE/TACE with ES were eligible. A total of 974 rHCC participants (485 participants treated with TACE/TAE and 489 participants treated with ES) were included in the present meta-analysis. TAE/TACE group was associated with lower risk of complications (OR = 0.36; 95% CI, 0.22–0.57; P

A large number of experiments show that PtCu catalyst has a good catalytic effect on methanol decomposition. Therefore, density functional theory (DFT) was used to further study the dehydrogenation of methanol catalyzed by PtnCum (n = 1–3, m = 0–2). The energy diagrams of O-adsorption path and H-adsorption path were drawn. By calculation, the Pt is the active site of the whole reaction process, and the barrier energy of the rate-determining step is 11.09 kcal mol−1 by Pt2Cu, which is lower than that of Pt3 and PtCu2. However, the complete dehydrogenation product of methanol, CO, is easier to dissociate from PtCu2 clusters than from Pt3 and Pt2Cu clusters. Therefore, Cu doping can improve the catalytic activity and anti-CO toxicity of Pt to a certain extent.

We have comparatively investigated the adsorption behaviors of Sc atom on the external and internal surfaces of the pristine, Stone-Wales (SW), and single-vacancy (SV) defect nanotubes based on the density functional theory. Our results reveal that the stability of Sc atom onto the external and internal surfaces of the carbon nanotubes is in following orders by defect: SV>SW1>SW2>pristine (external surfaces), SV>SW2>SW1>pristine (internal surfaces). To explore the reactivity of Sc@CNT/SW/SV complexes which can serve as a gas sensor or a catalyst in direct methanol fuel cell (DMFC), the interaction between a CO molecule and Sc@CNT/SW/SV is also examined. The SV defect in carbon nanotubes can make the confined Sc atom with good CO adsorption property, while the confined Sc in the SW defect carbon nanotube has good anti-CO poisoning. By our studies, it plays an important guidance role in improving the activity of metal catalyst and the sensitivity and stability of metal particles to functional molecules, and provides the theoretical basis for designing new carbon nanotube-based metal catalyst.

The reaction mechanism of the gas-phase PtCH2 + with H2S has been systematically investigated on the doublet and quartet potential energy surfaces at BPW91/6-311++G(2d, p)∪ SDD level. The Pt in PtCH2 + prefers to attack S–H bond in H2S. For PtCH2 + + H2S reaction, the potential energy surfaces (PESs), including three reaction pathways of hydrogen (including one and two hydrogen elimination) and methane elimination, have been explored and characterized. By contrast with hydrogen elimination, methane elimination reaction channel is energetically favorable, which is in good agreement with the experimental observation. The optimal S–H bond activation is the first step, followed by cleavage of Pt–C and Pt–S bond. About the path a and b, the lowering of activation barrier is mainly caused by the more stabilizing transition state interaction $$\varDelta E_{\text{int}}^{ \ne }$$ , which is the actual interaction energy between the deformed reactants in the transition state.

In the present work, density functional theory (DFT) is used to investigate the binding mechanism of atomic platinum on several heteroatom (Be, B, N, and O) doped (6, 6) single-walled carbon nanotubes. The binding abilities in ascending order by dopants are found to be pristine, nitrogen, boron, beryllium, and oxygen. The adsorption mechanisms of Pt on these nanotubes have been discussed based on the adsorption geometries, frontier orbitals, and projected density of states. Due to the unused binding site of the carbon atom created by O-doping, the O-doped CNT presents the strongest binding for atomic Pt. It is found that the degree of s-orbital of the carbon atom involved in the C–Pt bond could reflect the binding strength of Pt on these doped CNT supports.

Gas-phase CS2 activation by M+ (M = Ta, W, Re) was studied by the B3LYP density functional method.The geometries for reactants, transition states, and products were completely optimized. CS2 activation mediated by M+ (M = Ta, W, Re) were found to be a spin-forbidden process as a result of the crossing among the multistate energetic profiles. On the basis of the Hammond postulate, this was a typical two-state reactivity reaction. Among the different potential energy surfaces, the crossing points had been explored. The spin–orbit coupling (SOC) was also calculated between the electronic states of different multiplicities at the crossing point to estimate the intersystem crossing probability. For CP1, CP2, and CP4, the computed SOC constants were 80.28, 128.65, and 526.77 cm−1, which obtained by using one-electron spin–orbit Hamiltonian in Gaussian 09.

The mechanism of the cyclic reaction N2O(1∑) + CO(1∑+) → N2(1∑ g + ) + CO2(1∑ g + ) catalyzed by Re+ has been investigated on quintet and septet potential energy surfaces (PES). The reactions were studied by the B3LYP density functional method and the CCSD(T) theory. The calculated results of different PES show that the reaction proceeds in a two-step manner and spin crossing between different PES occurs. The involving crossing points (CPs) between the quintet and septet PES have been discussed by means of the intrinsic reaction coordinate approach. And the O-atom affinities testified that Re+ can capture O from N2O and transfer O atom to CO in the two spin state, which are thermodynamically allowed. Furthermore, the spin–orbit coupling (SOC) is calculated between electronic states of different multiplicities at the CPs. For CP1 and CP2, the computed SOC constants are 8.34 and 10.09 cm−1, respectively, obtained by using one-electron spin–orbit Hamiltonian in GAMESS. Therefore, the intersystem crossing at CP1 and CP2 occurs with a little probability because of the small SOC involved.

Nutrient loaded and non-loaded Chinese fir (Cunninghamia lanceolata (Lamb) Hook) seedlings were transplanted in a pot trial to examine effects of exponential nutrient loading and fertilization treatments on first season growth and N nutrition. The treatments tested four rates of N (0, 30, 60, and 90 mg tree-1) as a mixed NPK fertilizer applied before planting to create a soil fertility gradient, and two topdressings applied only to non-loaded seedlings later in the season. Nutrient loading alone consistently enhanced seedling growth on the four soil fertility classes, increasing respective biomass and N uptake 42, 45, 20 and 8%, and 65, 67, 29 and 18% more than non-loaded seedlings. The positive response was attributed to increased N retranslocation from higher nutrient reserves built up by loading during nursery culture. Net retranslocation from old shoots to new growth was highest soon after planting when nutrient stress was most severe. Pre-plant soil fertilization and post-plant topdressings were also effective in promoting seedling productivity, but equivalent additions yielded less biomass than that from nutrient loading alone. Implications are that exponential nutrient loading may be more efficient in improving early growth performance of Chinese fir seedlings than traditional field fertilization practices at plantation establishment, and may on competitive sites avoid problems of stimulating surrounding vegetation rather than trees.

Containerized Chinese fir (Cunninghamia lanceolata (Lamb) Hook) were reared from seed at four fertilizer levels (0, 15, 45, 75 mg N seedling-1 season-1) and two topdressing schedules (conventional or exponential) for a 22-week greenhouse rotation to assess growth, nutrition and nutrient loading capacity of seedlings. Extra P supplemented high fertilization (or nutrient loading) treatments to test for induced deficiency of this element. The schedule and rate of fertilization significantly affected growth and nutrient dynamics of the seedlings. Steady-state nutrition and superior growth performance were achieved by seedlings fertilized exponentially at the operational dose (15 mg N), yielding 23, 72 and 52% more in respective biomass, N uptake and P uptake than seedlings fertilized conventionally at the equivalent dose. The improved growth and fertilizer efficiency were attributed to close synchronization of exponential nutrient supply with exponential growth and nutrient demand of plants. High dose exponential fertilization (45 and 75 mg N) induced steady state-nutrition late in the season, increasing seedling N and P uptake by 72–83% and 50–96% compared to low dose exponential fertilization, demonstrating effective nutrient loading of plants without changing biomass. The extra P stimulated P uptake without altering growth or N uptake, thus P was probably not limiting during the greenhouse culture despite high N additions.