The effect of anticoagulants on venous thrombosis prevention after knee arthroscopy: a systematic review.

PURPOSE: Knee arthroscopy, with its unique advantages, has become a routine surgery and is widely carried out around the world. Venous thromboembolism (VTE) after knee arthroscopy is a potentially serious complication. This article analyzes the effects of anticoagulant therapy after knee arthroscopy. METHODS: We used key words or entry terms without any limitations to search the PubMed, Embase, and Cochrane Library databases. Randomized controlled trials (RCTs) of drug prophylaxis for VTE after knee arthroscopy until November 2017 were included in our review. RESULTS: This systematic review identified nine RCTs, consisting of 4290 patients, investigating drug prophylaxis in knee arthroscopy. There are three main drugs for preventing thrombosis after arthroscopic knee surgery: low-molecular-weight heparin (LMWH), rivaroxaban, and aspirin. Our study concluded that there is no difference in symptomatic VTE (excluding symptomatic distal DVT) risk during anticoagulant prophylaxis (RR, 0.98; 95% CI, 0.44-2.19; I2 value = 0%; P = 0.97). Moreover, there was a lower incidence of symptomatic distal DVT (RR, 0.16; 95% CI, 0.06-0.45; I2 value = 0%; P = 0.0005) in the anticoagulant group than in the control group. CONCLUSIONS: In our study, anticoagulant therapy after knee arthroscopy was ineffective. We recommend that anticoagulants not be provided routinely after knee arthroscopy.

[Preparation and property evaluation of graphene oxide based silver nanoparticles composite materials].

We prepared silver nanoparticles/polyethyleneimine-reduction graphene oxide (AgNP/rGO-PEI) composite materials, and evaluated their quality performance in our center. Firstly, we prepared AgNP/rGO-PEI, and then analysed its stability, antibacterial activity, and cellular toxicity by comparing the AgNP/rGO-PEI with the silver nanoparticles (PVP/AgNP) modified by polyvinylpyrrolidone. We found in the study that silver nanoparticles (AgNP) distributed relatively uniformly in AgNP/rGO-PEI surface, silver nanoparticles mass fraction was 4.5%, and particle size was 6-13 nm. In dark or in low illumination light intensity of 3 000 lx meter environment (lux) for 10 days, PVP/AgNP aggregation was more obvious, but the AgNP/rGO-PEI had good dispersibility and its aggregation was not obvious; AgNP/rGO-PEI had a more excellent antibacterial activity, biological compatibility and relatively low biological toxicity. It was concluded that AgNP/rGO-PEI composite materials had reliable quality and good performance, and would have broad application prospects in the future.

Establishment of a value evaluation system for health and wellness tourism resources: Reflections on China's official tourism resource evaluation criteria.

In recent years, China's sub-healthy and aging populations have increased dramatically, giving rise to a series of health and wellness needs. People prefer health and wellness tourism activities instead of sightseeing tourism activities because of the increasing emphasis on safety and experience. Health and wellness tourism resources are a prerequisite for the development of health and wellness tourism. To critically reflect on China's official tourism resource evaluation criteria, expert consultation was carried out by applying the Delphi method, and index weights were determined using the analytic hierarchy process. Through three rounds of expert consultation, a value evaluation system for health and wellness tourism resources was established and improved in three aspects: construction of an index system, selection of evaluation subjects, and grade discourse description, thus enhancing the feasibility and application value of the evaluation system. The system developed in this study not only enables a reflection on China's official tourism resource evaluation criteria, but also presents a new approach in the value evaluation research of health and wellness tourism resources.

Distinct seasonality in vertical variations of tropospheric ozone over coastal regions of southern China.

The surface ozone pollution is strongly coupled with ozone variations above the ground. Using sufficient airborne ozone profiles during 2012-2018, this study reveals the tropospheric ozone distributions over four cities located in coastal regions of southern China. The 7-year mean tropospheric ozone profiles in the four cities consistently show a double-maxima profile, with a local maximum at 1 km altitude and the other in the middle-to-upper troposphere. Seasonally, springtime ozone is larger than the annual mean throughout the troposphere, while ozone in summer is high in the middle-to-upper troposphere, leading to largest vertical variations among seasons. Ozone in the middle-to-upper troposphere is lower in autumn than in spring and summer. The winter ozone is characterized with a minimum in the lower troposphere, and low values in the middle-to-upper troposphere, leading to least vertical variations among seasons. We untangle the causes for these complicated vertical ozone variations using the GEOS-Chem model. The tropospheric ozone over southern China is partitioned into locally produced ozone, regionally transported native ozone, imported ozone from outside of China (foreign ozone) and natural stratospheric ozone. The results suggest that the springtime ozone abundance is due to the enhanced import of foreign and stratospheric ozone and the intensified regional transport processes of native ozone. In summer, local ozone production is enhanced and regional transport of ozone in the middle-to-upper troposphere is strengthened due to upward air motions, while such transport becomes weaker in autumn leaving low ozone in the middle-to-upper troposphere. In winter, the intensive westerly jets promote foreign and stratospheric ozone again in the middle-to-upper troposphere, but the local ozone production and regional transport are sharply reduced, resulting in low ozone near the surface. This study provides new insights into regional ozone profiles and reveals the significance of vertical ozone variations on surface ozone prevention strategy.

Speciation characterization of arsenic-bearing phase in arsenic sulfide sludge and the sequential leaching mechanisms.

Arsenic sulfide sludge (ASS) is a kind of deleterious waste which contains various valuable metallic elements, such as Re and Pb, which are always associated with arsenic-bearing phases in ASS. The leaching speed and efficiency of valuable elements may depend on the phase constitution. Here, we proposed a sequential leaching method to thoroughly understand the constitution of arsenic-bearing phase and the distribution of valuable elements in ASS. The results show that five major arsenic-bearing phases exist in ASS: amorphous As2S3, crystalline As4S4, As2O3, and As atoms dissolved into the lattice of PbS and PbSO4 phases. Re is mainly distributed in As2S3 and As4S4 phases. During the leaching process, the dissolution of As2O3 particles and As2O3 layers on the surface of As2S3/As4S4 particles occurs first. Then, the reaction between As2S3/As4S4 particles and copper sulfate happens. The order of leaching sequence is As2O3, amorphous As2S3 and crystalline As4S4. The majority of Re element exists in the solution while almost all Pb element remains in the solid residues, which is beneficial for the separation and purification valuable elements individually. This work not only detailed determines the arsenic-bearing species, but also provides significant theoretical bases for extracting valuable elements from ASS.