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The loss of skeletal muscle mass and muscle strength is common in patients suffering from chronic kidney disease (CKD) and end-stage renal disease (ESRD) undergoing dialysis. The purpose of this study was to conduct a meta-analysis to explore the relationship between physical functional performance and all-cause mortality in CKD and ESRD patients undergoing dialysis.A systematic literature search was conducted on an electronic database up to January 2022, and all data were analyzed using RevMan5 (version 5.3).Totally, 19 studies involving 6908 patients were enrolled for analysis. Patients with poor physical functional performance in the handgrip strength (HGS) (hazard ratio [HR] = 1.99, P 0.00001), gait speed (HR = 2.45, P = 0.0005), 6 m walk test (HR = 2.94, P 0.01), and timed up and go test (HR = 1.69, P = 0.02) showed increased risk of all-cause mortality than those with good physical functional performance. In continuous analyses, both per 1 kg increase in HGS (95% CI 0.94-0.98; P 0.00001; IThe present meta-analysis demonstrated that poor physical function outcomes, including grip strength, gait speed, 6MWT, and TUG test, were significantly associated with high all-cause mortality in patients with CKD and ESRD.

It remains unclear whether there is an association between posterior cruciate ligament (PCL) rupture and the medial posterior tibial slope (MTS) or lateral posterior tibial slope (LTS). The present case-control study aimed to investigate a possible association between primary PCL rupture and MTS or LTS measured by magnetic resonance imaging (MRI).A retrospective case-control study was conducted. Patients with primary PCL ruptures but not with anterior cruciate ligament injuries, were 1:1 matched by age and sex to a control group with no evidence of knee ligament injuries. Knee MRI was used to measure the MTS and LTS. In addition, the receiver operating characteristic (ROC) analysis was performed to identify an optimal cut-off value of the MTS and/or LTS.In total, 46 patients with PCL ruptures (32 males, 14 females) and 46 controls (32 males, 14 females) were included in this study. The MTS was significantly lower in the patients with PCL ruptures (3.0° ± 2.2°) than in the control group (5.1° ± 2.3°, p 0.001). The mean LTS/MTS ratio was significantly higher in patients with PCL ruptures (2.6 ± 2.5) than in the control group (1.3 ± 1.3, p = 0.001). However, the LTS was not significantly different between patients with PCL ruptures and the controls (4.4° ± 2.3° vs. 5.3° ± 2.6°, n.s.). After the MTS was determined to be a significant predictor, the ROC analysis was performed. The ROC analysis revealed the most accurate MTS cut-off of 3.9°, with a sensitivity of 76.1% and a specificity of 73.9%.A decreased MTS and an increased LTS/MTS ratio are associated with an increased risk of primary PCL rupture. People with MTS 3.9° are particularly at risk for PCL ruptures, and prevention and intervention programs for PCL ruptures should be developed and targeted towards them.Level III.

This study aimed to explore the functional roles of Shc SH2-domain-binding protein 1 (SHCBP1) and Kinesin Family Member 23 (KIF23) in HPV-negative head and neck squamous cell carcinoma (HNSCC).Bioinformatic analysis was conducted using data from The Cancer Genome Atlas (TCGA) and GSE103322. HNSCC cell lines were used for in vitro and in vivo analysis.SHCBP1 upregulation was associated with unfavorable survival. SHCBP1 knockdown reduced cell proliferation and increased the cisplatin sensitivity of SCC9/SCC25 cells. SHCBP1 interacted with KIF23 via its Nesd homology domain (NHD) domain, which was important for its nucleus localization. SHCBP1 positively modulated KIF23 expression and activated phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt), extracellular signal regulated kinase (ERK)1/2, nuclear factor kappa B (NF/κB)-p65, and Wnt/β-catenin signaling. KIF23 knockdown abrogated cisplatin resistance induced by SHCBP1 overexpression.SHCBP1 interacts with KIF23 and cooperatively regulates cell-cycle progression and cisplatin resistance of HNSCC tumor cells.

Herein, significant enhancement of second- and third-harmonic generation efficiencies in a 1 mol% Er3+ and 0.07 mol% Fe2+-doped lithium niobate single-crystal plate were achieved after ablating periodic cylindrical pit arrays on the surface. Enhanced absorption and reduced transmittance of light were measured when the incident light signal passed through the patterned sample. Enhanced photoluminescence and two-photon-pumped upconversion emission spectra were also explored to obtain more details on the efficiency gains. The excitation-energy-dependent second-harmonic generation efficiency was measured, and an enhancement as high as 20-fold was calculated. The conversion efficiency of second-harmonic generation is 1 to 3 orders higher than that from other lithium niobite metasurfaces and nanoantennas. This work provides a convenient and effective method to improve the nonlinear conversion efficiency in a thin lithium niobite plate, which is desirable for applying to integrated optical devices.

The purpose of this meta-analysis was to analyze the influences of sarcopenia on clinical outcomes in patients with biliary tract cancer (BTC). A systematic literature search was performed in November 2021. Some studies that reported the impacts of sarcopenia on the prognosis of patients with BTC were included. The overall hazard ratios (HRs), overall survival (OS), recurrence-free survival (RFS), and odds ratio (OR) for major postoperative complications were calculated using a fixed- or random effects. In the 18 studies, 3261 patients were enrolled for analysis. Based on defining sarcopenia by muscle mass, sarcopenia predicted OS, and based on defining sarcopenia by muscle density, HR was 2.10 (95% CI 1.72-2.56) and HR was 2.12 (95% CI 1.46- 3.10). Patients with sarcopenia had poorer RFS, and HR was 2.18 (95% CI 1.75-2.71). The incidence rate of major postoperative complication increased compared with those without sarcopenia (OR, 1.45; 95% Cl, 1.07-1.96). Sarcopenia is an independent risk factor for poor OS and RFS in patients with BTC. Sarcopenia is associated with the occurrence of major postoperative complications. This study provides advice that clinicians should provide importance to the assessment of skeletal muscle status and provide suitable nutritional supports and exercise program to reduce the sarcopenia in patients with BTC.

Background Anteromedial tibial plateau fracture with posterolateral corner (PLC) injury is a relatively rare combined injury in the clinic. In addition, there is no unified treatment scheme for this combined injury. The purpose of this study was to evaluate the clinical and imaging results of single-stage arthroscopic-assisted surgery for anteromedial tibial plateau fracture with PLC injury, and to explore the advantages of this surgical technique. Method In this retrospective study, a total of 9 patients (7 males and 2 females) were included, aged 24–64 years (average 40.7 years), treated in our Department of Orthopedics from January 2016 to January 2021. In the preoperative evaluations, there were 9 cases of anteromedial tibial plateau fractures with PLC injuries, 6 cases of concomitant PCL injuries, 6 cases of concomitant medial or lateral meniscus injuries, and 2 cases of concomitant fibular head avulsion fractures. All patients underwent single-stage arthroscopic-assisted surgery. Results All patients were followed up, and the average follow-up period was 15.2 months (range 12–18 months). The average operation time was 135.6 min (range 100–160 min), and the average surgical blood loss was 87.2 ml (range 60–110 ml). The anatomical reduction was achieved in 9 cases, and the anatomical reduction rate was 100%. The average fracture healing time was 13.1 weeks (range 12–16 weeks). At the last follow-up, the average VAS score was 1 (range 0–2); the average Lysholm function score was 90.7 (range 86–95), and the average IKDC score was 91.4 (range 88–95); the average knee extension angle of all patients was 0° and the average knee flexion angle was 128.3° (average 120–135°); The posterior drawer test, the Lachman test and the dial test were negative for all cases. None of the patients had operation-related complications. Conclusion Single-stage arthroscopy-assisted surgery in the treatment of anteromedial tibial plateau fracture with PLC injury can achieve good clinical outcomes, restore the stability of the knee joint, and reduce the risk of severe lower extremity dysfunction.

Resistive switching properties based on molecular beam epitaxy-grown monolayer hexagonal boron nitride (h-BN) atomristors are studied by using metal insulator metal configurations with different electrode materials. Au/monolayer h-BN/Ni devices demonstrate a forming-free bipolar resistive switching (BRS) behavior, a good endurance with up to 97 cycles at a high compliance current of 100 mA, an average on/off ratio of 103, and a low set/reset voltage variability. Metal/monolayer h-BN/graphite/Co devices exhibit self-compliant current BRS characteristics. Both metal/h-BN/Ni and metal/h-BN/graphite/Co devices show the coexistence of BRS, unipolar resistive switching (URS), and nonvolatile threshold switching (TH) modes. The formation of conductive filaments is attributed to the diffusion and trapping of metal ions on the defect sites driven by the electric field, while the rupture is driven by the electric field in BRS and by Joule heating in URS and TH modes.

Purpose Facetectomy is a useful procedure in percutaneous transforaminal endoscopic discectomy (PTED) for the enlargement of surgical field and operative space and for the decompression of existing nerve roots for patients who suffer foraminal stenosis. Biomechanical deterioration can initially trigger the adjacent segment disease (ASD), and our previous literature proved that a large grade of facetectomy can increase the risk of biomechanical deterioration and resulting low back pain. However, no study has discussed whether different grades of facetectomy influence the risk of ASD. Methods A validated osteoligamentous lumbosacral finite element model and corresponding PTED models with quarter and half facetectomy were constructed in our previous study. Biomechanical indicators were computed and recorded to evaluate the risk of ASD. Results Obvious differences between the intact model and the quarter facetectomy model had no basis. Nevertheless, in most body positions, most of the above indicators deteriorated in the half facetectomy model. Conclusion On the basis of achieving the surgical purpose in PTED, the superior articular process should be protected to decrease the risk of ASD biomechanically.

Two-dimensional (2D) hexagonal boron nitride (h-BN) plays a significant role in nanoscale electrical and optical devices because of its superior properties. However, the difficulties in the controllable growth of high-quality films hinder its applications. One of the crucial factors that influence the quality of the films obtained via epitaxy is the substrate property. Here, we report a study of 2D h-BN growth on carburized Ni substrates using molecular beam epitaxy. It was found that the carburization of Ni substrates with different surface orientations leads to different kinetics of h-BN growth. While the carburization of Ni(100) enhances the h-BN growth, the speed of the h-BN growth on carburized Ni(111) reduces. As-grown continuous single-layer h-BN films are used to fabricate Ni/h-BN/Ni metal-insulator-metal (MIM) devices, which demonstrate a high breakdown electric field of 12.9 MV/cm.

Direct tunneling and dielectric breakdown in molecular beam epitaxial hexagonal boron nitride (h-BN) monolayers were studied based on Ni/h-BN/Ni metal-insulator-metal (MIM) device structures. Effec...

Background The purpose of this study was to evaluate the clinical and radiographic outcomes after medial patellofemoral ligament (MPFL) reconstruction combined with supracondylar biplanar femoral derotation osteotomy (FDO) in recurrent patellar dislocation (RPD) with increased femoral anteversion angle (FAA) and genu valgum. Methods Between January 2017 to December 2020, a total of 13 consecutive patients (13 knees, 4 males and 9 females, mean age 18.7 (range, 15–29 years) with RPD with increased FAA (FAA > 25°) and genu valgum (mechanical axis deformity of ≥5°) who underwent supracondylar biplanar FDO using a Tomofix-locking plate combined with MPFL reconstruction in our institution were included. Preoperative full-leg standing radiographs, lateral views, and hip-knee-ankle computed tomography (CT) scans were used to evaluate the mechanical lateral distal femoral angle (mLDFA), anatomical femorotibial angle (aFTA), mechanical axis, patellar height, tibial tubercle-trochlear groove (TT-TG) distance, and torsional angle of the tibial and femoral in the axial plane. Patient reported outcomes were evaluated using the International Knee Documentation Committee (IKDC) score, Kujala score, Lysholm score, visual analog scale (VAS), and Tegner score preoperatively and postoperatively. Postoperative CT scans were used to evaluate the changes of FAA and TT-TG, and full-leg standing radiographs was used to evaluate the changes of mLDFA, aFTA, and mechanical axis. Results A total of 13 patients (13 knees) were included with an average follow-up period of 26.7 months (range 24–33). No cases developed wound infection, soft tissue irritation, and recurrent patellar dislocation during the follow-up period after surgery. Bone healing at the osteotomy site was achieved in all cases, and all patients regained full extension and flexion. Clinical outcomes (VAS, Kujala, IKDC, Lysholom, and Tegner scores) improved significantly at the final follow-up after surgery (p p p>0.05). Conclusion MPFL reconstruction combined with supracondylar biplanar FDO showed satisfactory clinical outcomes and radiographic results in the short-term follow-up period.

Purpose The protection of articular processes (AP) in the transforaminal endoscopic discectomy (TED) was proven to optimise post-operative biomechanical environments. Published studies reported a large grade of nuclectomy leading to poor prognosis, but the underlying biomechanical mechanism was unclearly illustrated. This study aimed to investigate the changes of biomechanical environments after an in-out TED with intact AP and a large grade of nuclectomy and an out-in TED with limited foraminoplasty and a smaller grade of nuclectomy. Methods A previously constructed and validated lumbo–sacral model was used in this study, and in-out TED with intact AP and out-in TED with limited foraminoplasty, a smaller grade of nuclectomy was simulated. Biomechanical changes in the L5–S1 segment related to the degeneration acceleration were computed under different directional loading conditions. Results Post-operative biomechanical changes after the out-in TED with limited foraminoplasty were slight, except for the facet contact pressure under the extension position. By contrast, significant biomechanical deterioration, both in the adjacent disc and zygapophyseal joints, is observed under extension in the model after the in-out TED with large nuclectomy. Conclusion A large grade of nuclectomy is regarded as an independent risk factor of adjacent segment disease in the caudal functional spinal unit after the in-out TED.

BACKGROUND: The aim of the present study was to systematically evaluate the application value and complications of 3D printing technology on Schatzker tibial platform fracture surgery. METHODS: By searching the Cochrane Library, PubMed, Web of Science, Embase, Chinese Biomedical Literature Database (CBM), screening randomized controlled trials (RCTs), and two researchers included the study according to PICOS criteria and performed bias risk assessments. Quality evaluation and data extraction were performed for the included literatures, and meta-analysis was performed for RCTs included at using Review Manager 5.2 software. RESULTS: A total of 15 articles were included in the present study, which included a total of 758 patients, 342 3D printing techniques, 416 conventional surgical procedures. Meta-analysis showed 3D printing operation time [risk difference (RD) =−0.12, 95% CI: −0.16, −0.08, I(2)=46%, P

Background The purpose of this study was to evaluate the clinical and radiographic outcomes after medial patellofemoral ligament (MPFL) reconstruction combined with supracondylar biplanar femoral derotation osteotomy (FDO) in recurrent patellar dislocation (RPD) with increased femoral anteversion angle (FAA) and genu valgum. Methods Between January 2017 to December 2020, a total of 13 consecutive patients (13 knees, 4 males and 9 females, mean age 18.7 (range, 15–29) years) with RPD with increased FAA and genu valgum who underwent supracondylar biplanar FDO using a Tomofix-locking plate combined with MPFL reconstruction in our institution were included. Preoperative full-leg standing radiographs, lateral views, and hip-knee-ankle computed tomography (CT) scans were used to evaluate the mechanical lateral distal femoral angle (mLDFA), patellar height, tibial tubercle-trochlear groove (TT-TG) distance, and torsional angle of the tibial and femoral in the axial plane. Patient reported outcomes were evaluated using the International Knee Documentation Committee (IKDC) score, Kujala score, Lysholm score, visual analog scale (VAS), and Tegner score preoperatively and postoperatively. Postoperative CT scans were used to evaluate the changes of FAA and TT-TG, and full-leg standing radiographs was used to evaluate the changes of mLDFA. Results A total of 13 patients (13 knees) were included with an average follow-up period of 14.7 months (range 12–26). No cases of patients developed wound infection, soft tissue irritation, and recurrent dislocation during the follow-up period after surgery. Bone healing at the osteotomy site was achieved in all cases, and all patients regained full extension and flexion. Clinical outcomes (VAS, Kujala, ICDC, Lysholom, and Tegner scores) improved significantly at the final follow-up after surgery (p p༞0.05). The mean FAA significantly decreased from 32.77°±3.78° to 19.08°±3.14°, while the tibial torsion did not change significantly after surgery (p༞0.05). Conclusion MPFL reconstruction combined with supracondylar biplanar FDO showed satisfactory clinical outcomes and radiographic results in the short-term follow-up period.

Background Due to atypical clinical symptoms, it is difficult to diagnose joint tuberculosis infection, which often results in misdiagnosis and missed diagnosis. It is easy to cause joint disability. And there are few reports of using arthroscopy to diagnose and treat shoulder tuberculosis. This case series aims to introduce the clinical outcomes of arthroscopic treatment of shoulder tuberculosis. Methods Twenty-nine patients with shoulder tuberculosis from September 2013 to February 2019 were included (10 males, 19 females; age range from 22 to 69; the average age is 37.6 years). All patients underwent arthroscopic lesion debridement, with preoperative and postoperative regular use of isoniazid, rifampicin, pyrazinamide, and streptomycin quadruple anti-tuberculosis drugs. The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were recorded before and at the last follow-up. The shoulder function was evaluated according to the visual analogue scoring method (visual analogue scale, VAS) pain score and Constant score. Results Twenty-nine patients were followed up from 12 months to 2 years, and the average follow-up time was 15.7 months. The pathological diagnosis of all patients after surgery was shoulder tuberculosis. No serious complications were found at the last follow-up, and the incision healed well. VAS pain score, Constant score, ESR, and CRP at the last follow-up were significantly improved compared with those before treatment (P < 0.05). Conclusion On the basis of the standard use of anti-tuberculosis drugs before and after surgery, shoulder arthroscopy is used to treat early and mid-term shoulder tuberculosis, which can be diagnosed by direct observation under the arthroscope and postoperative pathological examination. It has the advantages of thorough lesion removal, minimal invasiveness, rapid recovery, and reliable clinical effect.

Reliable and controllable synthesis of two-dimensional (2D) hexagonal boron nitride (h-BN) layers is highly desirable for their applications as 2D dielectric and wide bandgap semiconductors. In this work, we demonstrate that the dissolution of carbon into cobalt (Co) and nickel (Ni) substrates can facilitate the growth of h-BN and attain large-area 2D homogeneity. The morphology of the h-BN film can be controlled from 2D layer-plus-3D islands to homogeneous 2D few-layers by tuning the carbon interstitial concentration in the Co substrate through a carburization process prior to the h-BN growth step. Comprehensive characterizations were performed to evaluate structural, electrical, optical, and dielectric properties of these samples. Single-crystal h-BN flakes with an edge length of ∼600 μm were demonstrated on carburized Ni. An average breakdown electric field of 9 MV/cm was achieved for an as-grown continuous 3-layer h-BN on carburized Co. Density functional theory calculations reveal that the interstitial carbon atoms can increase the adsorption energy of B and N atoms on the Co(111) surface and decrease the diffusion activation energy and, in turn, promote the nucleation and growth of 2D h-BN.

We report on the low-temperature scanning tunneling microscopy (STM) measurements of the self-assembly of nonplanar 10,10′-dibromo-9,9′-bianthryl (DBBA) molecules on Ag(111) combined with density functional theory (DFT) calculations. DBBA molecules have two enantiomorphous adsorption configurations, from which more chiral structures can be formed. At a low coverage [0.4 monolayer (ML)], DBBA forms racemic netlike islands consisting of molecular chains along ⟨1 2 3⟩Ag. Moreover, the gliding between the molecular chains gives rise to chiral windmill-like patterns in the islands. At 0.8 ML, DBBA forms a racemic row phase and a homochiral hexamer phase. The molecular appearance difference between the two coexisted phases and the DFT calculated molecular adsorption configuration reveal a decrease in the molecular dihedral angle of DBBA, which implies an enhancement in the intermolecular interactions via CH···π and halogen bonds. The transition from a racemic packing mode to a homochiral one suggests that the ...

Controllable wafer-scale growth is one of the ultimate goals in two-dimensional (2D) h-BN synthesis, which is not fully accomplished to date. One of critical issues is the formation of three-dimensional (3D) islands (adlayers) within 2D layers, thus the films are non-uniform in thickness. In this paper, we present a study of h-BN adlayer growth and provide a strategy towards eliminating these adlayers for the precise control of the number of 2D layers. By varying the growth parameters such as substrate property, nitrogen source composition, and substrate carburization time, we found that the adlayer growth can be controlled by controlling the nucleation and intercalation processes, which is achieved by engineering the defects and impurities on substrate and the activeness of the h-BN edges. While crystallographic defects and impurities stimulate the multilayer nucleation process, activated edge tends to turn off the intercalation process by reducing the probability of precursors penetrating into the interface. We have achieved the growth of a large-area adlayer-free single-layer h-BN film.

The Ocean Salinity (OS) Satellite mission of the State Oceanic Administration of China dedicates to an “all-weather” estimate of high-quality global SSS and to reduce geophysical errors due to surface roughness and sea surface temperature from space. The payload of this mission has the capability of L/C/K multi-frequency passive and L-band active measurement, and can implement the simultaneously remote sensing of SSS, SST, WS and atmospheric parameters. The OS Satellite data processing prototype software has been developed to simulate the instrument and to generate Level 0 to Level 2 data. Based on the prototype software, the end to end study of the OS Satellite mission is performed and the errors of simultaneous retrieval of multiparameters are analyzed and noises level and stability requirement of instruments are estimated.

Low-temperature scanning tunneling microscope investigations reveal that hexabromobenzene (HBB) molecules arrange in either hexagonally closely packed (hcp) [Formula: see text] or tetragonal [Formula: see text] structure on Au(111) dependent on a small substrate temperature difference around 300 K. The underlying mechanism is investigated by density functional theory calculations, which reveal that substrate-mediated intermolecular noncovalent C-Br···Br-C attractions induce hcp HBB islands, keeping the well-known Au(111)-22×√3 reconstruction intact. Upon deposition at 330 K, HBB molecules trap freely diffusing Au adatoms to form tetragonal islands. This enhances the attraction between HBB and Au(111) but partially reduces the intermolecular C-Br···Br-C attractions, altering the Au(111)-22×√3 reconstruction. In both cases, the HBB molecule adsorbs on a bridge site, forming a ∼15° angle between the C-Br direction and [112̅]Au, indicating the site-specific molecule-substrate interactions. We show that the competition between intermolecular and molecule-substrate interactions determines molecule packing at the subnanometer scale, which will be helpful for crystal engineering, functional materials, and organic electronics.

We carried out a systematic study of hexagonal boron nitride/graphene (h-BN/G) heterostructure growth by introducing high incorporation of a carbon (C) source on a heated cobalt (Co) foil substrate followed by boron and nitrogen sources in a molecular beam epitaxy system. With the increase of C incorporation in Co, three distinct regions of h-BN/G heterostructures were observed from region (1) where the C saturation was not attained at the growth temperature (900 °C) and G was grown only by precipitation during the cooling process to form a 'G network' underneath the h-BN film; to region (2) where the Co substrate was just saturated by C atoms at the growth temperature and a part of G growth occurs isothermally to form G islands and another part by precipitation, resulting in a non-uniform h-BN/G film; and to region (3) where a continuous layered G structure was formed at the growth temperature and precipitated C atoms added additional G layers to the system, leading to a uniform h-BN/G film. It is also found that in all three h-BN/G heterostructure growth regions, a 3 h h-BN growth at 900 °C led to h-BN film with a thickness of 1-2 nm, regardless of the underneath G layers' thickness or morphology. Growth time and growth temperature effects have been also studied.

Research on graphene/hexagonal boron nitride (h-BN) heterostructures has attracted much attention for band engineering and device performance optimization of graphene. However, the growth of graphene/h-BN heterostructure is still challenging, which usually requires high growth temperature and long growth duration. In this paper, we demonstrate graphene/h-BN heterostructures by growing graphene onto the substrates which consist of exfoliated h-BN flakes on Co thin films using molecular beam epitaxy. The heterostructure samples grown at different temperatures and growth times were characterized by Raman, optical microscopy, atomic force microscopy, microwave impedance microscopy, and scanning tunneling microscopy. It is found that the graphene/h-BN heterostructures were formed by the formation of graphene underneath rather than on top of the h-BN flakes. The growth mechanism is discussed.

Molybdenum disulfide (MoS2) has recently attracted considerable interests due to its unique properties and potential applications. Chemical vapor deposition (CVD) method is used widely to grow large-area and high-quality MoS2 single crystals. Here, we report our investigation on thermal strain-fractured (SF) single crystalline MoS2, oxidation-fractured MoS2, and normal MoS2 by atomic force microscopy (AFM), Raman and photoluminescence (PL) measurements. Several new Raman modes are observed for SF-MoS2. The band gap of SF-MoS2 is enlarged by 150 meV and the PL intensity is reduced substantially. These results imply that a structural transformation occurs in SF-MoS2. Our findings here are useful for the design of MoS2-based nanocatalysts with relative high catalytic activity.

AP placement is a vital design issue for deploying an 802.11 Wireless Local Area Networks system. In this paper, a comprehensive solution including modeling of WLAN and optimization of coverage rate is presented to enhance economy, practicability and adaptability of WLAN system. A novel matrix model of WLAN system (MMWS) is established by mapping a power matrix to a corresponding effective coverage element (ECE) matrix in a target area. Providing that transmitting power and user demands are given, a optimization algorithm comprising some adapted GA operators is proposed to deploy the logical Access Points (APs) for obtaining maximized coverage rate (CR). Meanwhile, a new fitness function is provided to assess the network coverage and improve the crossover/mutation operations. By experiments on synthetical data, performance of our method is evaluated and analyzed in detail. The results indicate that the effective CR of a target area obtained by the proposed method has exceeded 95%, and the co-channel interference has been avoided to the utmost extent. It is evident that the proposed solution is practical to optimize the CR of WLANs.

Urban gridding management model creates a new era of urban management. Scientific and rational division of the grid can carry truly out a new concept of urban governance: fining, gridding, information, humanization. Service GIS is a Service-Oriented Architecture (SOA) of the Component GIS. It brings the third generation of geographic information-sharing revolution which is data sharing and function sharing, but also successfully opens the era of geo-information services aggregation. Urban gridding management system based on service GIS mainly researches that the use of gridding technology and service GIS technology implement data resource of urban gridding integration and sharing under the SOA architecture, but also on urban management process eliminate emergency phenomenon of 'information silos' and 'information chimneys' and so on. The establishment of urban management mechanism which is collaborative management, operation efficiency, data and function sharing bring greatly out social and economic benefits of urban construction.

In order to solve the problems which digital mine is facing, a solution of digital mine based on grid GIS is put forward in this paper. Firstly, the paper systematically introduces the grid and its architecture, and the concept of grid GIS; then designs the digital mine system based on grid GIS. Digital mine construction is one of the important means to maintain the sustainable development of mining; grid GIS can provide effective technical support to it. Digital mine was introduced after the concept of the digital earth. A digital mine is set up on the basis of digitalization, informationization, virtualization and integration, and it is a unified system of management and controlling of computer network. It integrates various factors such as production, management, administration, environment, resources, and safety and benefits so that the enterprise can be developed harmoniously under the condition of "green" mining to improve the competitive ability and adaptability of coal enterprises