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We demonstrated the pyrroles prefer to form a C–C or C–N covalent bond in its clusters after one-photon ionization, which may help to elucidate the mechanism of DNA damage at a molecular level.

Purpose Single-incision laparoscopic appendectomy (SILA) is usually performed using single-port instruments, which may restrict its development and application. This study explored the performance of transumbilical SILA (TSILA) and suprapubic SILA (SSILA) using only conventional laparoscopic instruments and compared them with conventional three-hole/port laparoscopic appendectomy (CLA). Methods This retrospective study included 174 patients who underwent CLA, TSILA, or SSILA for acute appendicitis at our hospital between June 2019 and July 2021. Demographic data and clinical outcomes were compared among the three groups. Results Compared with CLA, TSILA was associated with significant reductions in postoperative pain, length of hospital stay, and hospital cost, while SSILA was associated with significant reductions in length of hospital stay and hospital cost (all P P P = 0.039). Besides, compared with TSILA, SSILA showed significantly higher postoperative pain score (2 ± 2 vs 3 ± 2, P = 0.006). Mild incisional or intraabdominal infections were noticed in 2 (3.0%) patients in the CLA group, 3 (5.1%) in the TSILA group, and 3 (6.3%) in the SSILA group (P = 0.69). Conclusion SILA performed with only conventional laparoscopic instruments was associated with reduced hospital stay and cost and higher cosmetic satisfaction in comparison to CLA. However, it is technically demanding and may increase operative time.

In order to study the effect of microcrystalline cellulose on the reaction kinetics of polyurethane, in this work, the multi-scale microcrystalline cellulose was added to the foaming system of multifunctional polyether and multifunctional MDI polyurethane. While the chemical reaction was carried out, it was found through in situ FTIR combined with in situ rheological analysis that what was different from the usual inorganic fillers, the hydroxyl on the surface of the microcrystalline cellulose could preferentially react with MDI to generate urethane under the action of the catalyst. In the initial 5–6 min of the reaction, the reaction of soft segment chain growth was the main reaction. Then the main reaction quickly converted to the cross-linking reaction, which greatly increased the viscosity of the system. The addition of microcrystalline celluloses accelerated the improvement of the cross-linking degree and viscosity of the system. The higher the surface hydroxyl content of microcrystalline cellulose, the more significant this trend become. In addition, although the amount of microcrystalline cellulose added was different, the ratio of the reaction rate of the isocyanate group with the hydroxyl group and the amine group eventually tended to be constant, which indicated that there was a stable reactivity rate in the gradual addition reaction during the cross-linking reaction. Combined with SEM analysis, it was found that 25–60 μm microcrystalline cellulose with large hydroxyl content could act as a nucleating agent when the addition amount was less than 0.1%, which was beneficial to increase the cell density and reduce the pore size and improved the impact performance of the foam. The microcrystalline cellulose with a length of more than 90 μm continuously penetrated through several cell walls and destroyed integrity of the cell structure, which would consequently reduce the impact strength of the foam. This paper provided theoretical guidance for polyurethane modified by microcrystalline cellulose.

Carrier separation and surface reaction kinetic are two main bottlenecks limiting photocatalytic efficiency of photocatalysts towards an industrial level. In this regard, heterostructures and defects engineering have been proven to be effective strategies for addressing the two issues. However, the integrated construction of heterostructures and defects has been reported rarely. Herein, a facile in-situ photodeposition strategy has been developed to grow CdS nanocrystals on MnO

The equilibrium relations for water and sediment transport refer to the relative balance of sediment transport and the relative stability of river courses formed by the automatic adjustment of riverbeds. This is the theoretical basis for the comprehensive management of sediment in the Yellow River. Based on the theories of sediment carrying capacity and the delayed response of riverbed evolution, in this study, the equilibrium relations for water and sediment transport in the Yellow River are established. These relations include the equilibrium relationships between water and sediment transport and bankfull discharge in the upper and lower Yellow River and between water and sediment transport and the Tongguan elevation in the middle Yellow River. The results reveal that for the Ningmeng reach, the Tongguan reach, and the lower Yellow River, erosion and deposition in the riverbeds are adjusted automatically, and water and sediment transport can form highly constrained equilibrium relationships. These newly established equilibrium relationships can be applied to calculate the optimal spatial allocation scheme for sediment in the Yellow River.

Developing suitable catalysts capable of receiving injected electrons and possessing active sites for hydrogen evolution reaction (HER) is the key to building an efficient dye-sensitized system for hydrogen production. Fe3S4 is generally regarded as an inferior HER catalyst among the metal sulfide family, mainly due to its weak surface adsorption toward H atoms. In this work, we demonstrate a facile metal-organic framework-derived method to synthesize uniform Fe3S4 nanorods and active them for HER by Ni doping. Our experimental results and theoretical calculations reveal that Ni doping can greatly modify the electronic structure of Fe3S4 nanorods, improving their electron conductivity and optimizing their surface adsorption energy toward H atoms. Sensitized by a commercial organic dye (eosin-Y), 1%Ni-doped Fe3S4 nanorods display a high H2 production rate of 3240 μmol gcat-1 h-1 with an apparent quantum yield of 12% under 500 nm wavelength, which is significantly higher than that of pristine Fe3S4 and even higher than that of 1% Pt-deposited Fe3S4. The working mechanism of this dye-sensitized system is explored, and the effect of Ni-doping concentration has been studied. This work presents a facile strategy to synthesize metal-doped sulfide nanocatalysts with greatly enhanced activity toward photocatalytic H2 production.

Computational and condensed phase experimental evidence for the existence of S∴N and S∴O hemibonded structures has been reported previously, but no gas phase experimental evidence has been reported. To experimentally explore the existence of the S∴N and S∴O hemibonds in the gas phase, we recorded the infrared photodissociation action spectra of four cationic clusters: [CH

Improving the reaction selectivity and activity for challenging substrates such as nitroaromatics bearing two reducible functional groups is important in industry, yet remains a great challenge using traditional metal nanoparticle based catalysts. In this study, single metal atom doped M-C2N catalysts were theoretically screened for selective hydrogenation of 3-nitrostyrene to 3-vinylaniline with H2 as the H-source. Among 20 M-C2N catalysts, the non-noble Mn-C2N catalyst was found to have excellent reaction selectivity. Importantly, due to the solid frustrated Lewis pair sites in the pores of Mn-C2N, a low H2 activation energy is achieved on high-spin Mn-C2N and the rate-determining step for the hydrogenation reactions is the H diffusion from the metal site to the N site. The unraveled mechanism of the hydrogenation of 3-nitrostyrene using Mn-C2N enriches the applications of Mn based catalysts and demonstrates its excellent properties for catalyzing the challenging hydrogenation reaction of substrates with two reducible functional groups.

Transition-metal cluster-encapsulated UiO-66 composites have attracted great interest because of their excellent properties in catalysis, yet it is still a great challenge to explore the structures...

It is well-known that functional groups should greatly affect the electronic properties of the metal cluster-encapsulated metal–organic frameworks and thus change their catalytic properties; howeve...

Background: Intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC) have different cellular origins; therefore, ICC is significantly different from HCC in terms of aetiology, mechanism, tumour biological behaviour, treatment methods, and prognosis. The objective of this study was to investigate the current incidence trend and prognosis of intrahepatic cholangiocarcinoma (ICC) and deepen the understanding of ICC. Methods A large sample of ICC and hepatocellular carcinoma (HCC) patient data was obtained from the Surveillance, Epidemiology and End Results (SEER) database of the National Cancer Institute (NCI), USA. The incidence trend, prognosis, and the effect of surgery and lymph node dissection on the prognosis of ICC patients were analysed. Results In recent years, the incidence of ICC has increased. The prognosis of ICC patients is significantly worse than that of HCC patients. Surgery can benefit all stages of ICC, and lymph node dissection is beneficial for the prognosis of patients with positive lymph nodes (N1). Conclusion In recent years, the incidence of ICC has been increasing, and its prognosis remains poor, which is a cause for concern.

Utilizing sunlight to convert CO

Improving the reaction selectivity and activity for challenging substrates such as nitroaromatics bearing two reducible functional groups is important in industry, yet remains a great challenge using traditional metal nanoparticle based catalysts. In this study, single metal atom doped M-C

Developing suitable catalysts capable of receiving injected electrons and possessing active sites for hydrogen evolution reaction (HER) is the key to building an efficient dye-sensitized system for hydrogen production. Fe

This thesis presents research work on deformable surface model for 3D object segmentation. Over the past decades, there have been many research activities in 3D object segmentation using 3D and 2D deformable models. Full 3D methods will produce much better results than those obtained based on the 2D ones. Contextual intensity information of one voxel in one direction will be lost in each 2D image. Furthermore, a post-processing step is required to connect the sequence of 2D contours in a continuous surface. Reconstruction of the surface will be difficult if the topology of 2D contours is complicated. Therefore, it is desired to detect objects in 3D space directly to avoid the shortcomings of 2D methods, especially in application to 3D medical image analysis. DOCTOR OF PHILOSOPHY (EEE)

In high-speed rail (HSR) with Long-Term Evolution (LTE) technology, the wireless communication quality of service (QoS) is enormously degraded because of the unstable signal and frequent handover. Recently, a seamless handover using two antennas on the top of a train has been introduced to provide a better user experience. The two antennas are mounted on the front and the rear of the train, respectively, so that one performs handover, and the other is communicating. A bicasting mechanism is adopted to eliminate the delay and overhead of data forwarding. In this paper, we consider a new algorithm to optimize the handoff opportunity by investigating not only the hysteresis exceeding level but the signal strength of both antennas as well. The parameter selection in the algorithm is analyzed based on a probability model. Furthermore, a set of new handover procedures, which optimize the utilization of the two antennas, is proposed to decrease the overhead and improve the QoS of the users. Accordingly, numerical results show that the handover failure probability (HFP) and the communication interruption probability (CIP) are both obviously reduced.

LTE with large capacity and high speed is the most promising standard of wireless data communications technology to be used in Chinese high-speed rail(HSR). Because of over-frequent handover in HSR, the experience of passengers is highly degraded. Wireless Quality of Service (QoS) provisioning in such high speed movement is more difficult to be tackled than in a fixed-wired environment. Seamless handover attempts to provide a given QoS during the process of migration from one cell to another. It can reduce the interruption period to nearly zero. In this paper, we revised an existent seamless dual-link handover scheme where the Train Relay Station relays the data of users in the train and two antennas are mounted in the top of the train and designed a set of new handover procedures suitable for HSR communications. We defined a velocity threshold(VT). If the speed of train exceeds VT, two target base stations are prepared for user equipment(UE) when handover is triggered. The simulation results show that in the proposed scheme the communication interruption probability is under 0.01 when the train is at speed of 350 kilometers per hour.

A new method, called 3D growing deformable B-surface model, is proposed for object detection which works in 3D space directly. First, the coarse boundary of the subject is extracted. The 3D external force field of the subject is generated based on this coarse boundary using modified GVF (gradient vector flow). After the initialization of a surface patch, growing B-surface model starts to deform it to locate the boundary of the object. Next, this surface patch is anchored to the surface of the subject and a new surface patch grows up based it. This process is repeated until a closed surface of the subject is obtained. 3D growing deformable B-surface model overcomes the difficulty that comes from analyzing 3D volume image slice by slice. And the computation load of B-surface is reduced since the internal force is not necessary in every iteration deformation step. Next, the geometric information on every surface point can be calculated easily. And it has the ability Io achieve high compression ratio (the ratio of data to parameters) by presenting the whole surface with only a relatively small number of control points. Growing B-surface model simplifies the initialization step of the surface model.