16 research outputs found

    Validity and Reproducibility of a Revised Semiquantitative Food Frequency Questionnaire (SQFFQ) for Women of Age-group 12-44 Years in Chengdu

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    To find a credible nutritional screening tool for evaluating relationship between nutritional status and diseases in Chengdu female residents, the reliability and validity of a revised semi-quantitative food frequency questionnaire (SQFFQ) were tested. The validity was assessed by comparing the SQFFQ with the \u2018standard\u2019 method of 3 days\u2019 dietary recall, and the reliability was assessed by comparing the first SQFFQ with the second SQFFQ at 4 weeks interval. Correlation analysis showed that, for reliability, the average correlation coefficient (CC) of 22 kinds of nutrients was 0.66 and reduced to 0.60 after adjusting for energy; the average of intra-class correlation coefficients (ICC) was 0.65. For validity, the average CC was 0.35 and remained stable after adjusting for CC of energy or nutrients. Validity of 17 nutrients in SQFFQ survey had correlation with result of 3 days\u2019 dietary recall. The results showed that the revised SQFFQ can be used for investigating the role of nutrients in development of disease in Chengdu female residents

    Distributions, sources, and air-sea fluxes of nitrous oxide in Bohai Bay, China

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    IntroductionPolluted bays are one of the critical areas for the production and emissions of marine nitrous oxide (N2O), which has a strong effect on global warming and plays a critical role in stratospheric ozone depletion.MethodsIn 2020, the distributions of N2O concentrations and emissions in the water column of Bohai Bay (BHB) were surveyed during two cruises.Results and discussionThe average N2O concentrations were higher in summer compared to autumn, with the oversaturation of N2O in both seasons. A declining gradient of N2O was found from the Hai River and Yellow River estuarine areas to the offshore sea, particularly in summer, implying riverine input was an important source of N2O. The vertical distribution of N2O was uniform in each season owing to the vertical mixing of water columns in the offshore sea, with N2O hotspots at the bottom of the two estuaries in summer and at the surface of the Hai River estuary in autumn. Moreover, the dominant sources of dissolved N2O were analyzed. N2O in the water column was predominately produced by nitrification and coupled nitrification-denitrification on suspended particulate matter. The mixing of water masses, particularly polluted water masses from coastal input, provides high N2O to the entire area of BHB, particularly in summer. Notably, nutrient and organic matter input from the coast could also indirectly drive N2O production by stimulating microbe activities of nitrification and denitrification under the water currents. In addition, statistical analysis revealed that ammonium, dissolved oxygen, and temperature were the dominant controlling factors of N2O in BHB. The annual flux of N2O in BHB was evaluated to be 6.5 Gg, accounting for 0.15% of the global oceanic N2O emission with 0.0044% of the global ocean area. Hence, as a typical polluted bay, BHB acted as a strong N2O source to the atmosphere on a per-unit-area basis

    A Nonlinear Dynamic Model for Characterizing the Downhole Motions of the Sidetracking Tool in a Multilateral Well

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    It is of practical interest to investigate the mechanical behaviors of a sidetracking tool system and to describe the sidetracking tool’s vibration mechanical response, as this can provide an important basis for evaluating and optimizing the tool structure and effectively controlling the profile of the sidetracking window. In this article, three nonlinear dynamic models with ten, six, and two degrees of freedom, respectively, are established using the Lagrange method to characterize the behavior of the sidetracking tool. It should be noted that in these models, the axial, lateral, and torsional vibration of the tool system are fully coupled. The process of the sidetracking tool mills in the casing-pipe wall is divide into three typical stages, i.e., the window mill, pilot mill, and watermelon mill grinding the casing, respectively. The dynamic response of the three stages is studied to more effectively analyze the influence of the sidetracking tool vibration deformation on the window width. The Runge–Kutta method, which is easy to implement, is applied to solve the supposed nonlinear dynamic model, and some useful findings are as follows. The effects of sidetracking tool vibrations at different stages on window widening size are illustrated quantitatively. The vibration trajectory pattern of the sidetracking tool is different from that of the conventional drilling tool due to the influence of the whipstock, which changes from the general whirling motion pattern to the X reciprocating pattern, and the vibration amplitude decreases. Due to the influence of the tool’s lateral amplitude, the window profile is widened. The widened window size of the window mill and the pilot mill are 3.30 mm and 2.74 mm, respectively, and the extended window size of the watermelon mill is 0.07 mm, while the maximum window width formed by the sidetracking tool is 374.34 mm. This work proposes, for the first time, the coupled vibration model of the sidetracking tool system, which is helpful to better understand the nonlinear dynamic effects of the sidetracking tool, laying the foundation for the optimization of the sidetracking parameters

    Improvement of corn stover fuel properties via hydrothermal carbonization combined with surfactant

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    Background Biomass fuel has been used to supply heat or crude materials in industry to replace the traditional fossil fuel which was one of the chief causes of climate warming. However, the large-scale utilization of biomass fuel was restricted due to the low density and high hydrophilicity of biomass, which causes the problem of transportation and storage. Therefore, pelletization of biomass was used to improve its fuel density. At present, the biomass pellet was widely used to supply heat, gas or electricity generation via gasification, which supplied clean and sustainable energy for industry. However, the energy consumption during pelletization and high hydrophilicity of pellets were still the problem for the large-scale application of biomass pellet. In this study, hydrothermal carbonization and surfactant played the role of permeation, adsorption and wetting in the solution, which was expected to improve the fuel properties and pelletization effectivity of corn stover. Results In the article, surfactant (PEG400, Span80, SDBS) was chosen to be combined with wet torrefaction to overcome the drawbacks and improve the pelletization and combustion properties of Corn stover (CS). Especially, hydrothermal carbonization (HTC) combined with surfactant improves the yield of solid products and reduces the ash content of solid product, which was beneficial for reducing the ashes of furnace during gasification. Meanwhile, surfactant promotes the formation of pseudo-lignin and the absorption for oil with low O and high C during HTC, which improves the energy density of solid product. Furthermore, the oil in solid product plays the role of lubricant and binder, which reduces the negative effect of high energy consumption, low bulk density and weak pellets strength caused by HTC during pelletization. HTC combined with surfactant improved the hydrophobicity of pellet as well as grindability due to the modification of solid product. Moreover, surfactant combined with HTC improved the combustion characteristic of solid product such as ignition and burning temperature as well as kinetic parameters due to the bio-oil absorbed and the improvement of surface and porosity. Conclusions The study supplied a new, less-energy intensive and effective method to improve the pelletization and combustion properties of corn stover via hydrothermal carbonization combined with surfactant, and provided a promising alternative fuel from corn stoverISSN:1754-683

    Transvaginal natural orifice endoscopic surgery for tubal ectopic pregnancy: A more suitable surgical approach for enhanced recovery after surgery

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    Objective: We aimed to determine the safety of Vaginal natural orifice transluminal endoscopic surgery (vNOTES) in terms of the Enhanced Recovery after Surgery (ERAS) concept for tubal pregnancy surgery and provide a detailed process of vNOTES for tubal pregnancy surgery, including experience and key points for surgeons performing this procedure. Methods: The Longitudinal Vaginal Natural Orifice Transluminal Endoscopic Surgery Study (LovNOTESS), which was conducted in Chengdu, China. A total of 219 patients who underwent tubal ectopic pregnancy surgery between September 2021 and March 2022. The patients underwent salpingectomy or salpingostomy using transumbilical laparoendoscopic single-site surgery (LESS) or vNOTES, according to their preferences. This study prospectively collected perioperative and one-year follow-up data on tubal pregnancy outcomes after vNOTES and compared them with those after LESS. Results: The vNOTES group showed a shorter surgical duration, hospitalization duration, and postoperative exhaust time and a lower analgesic medication usage rate, but it showed a higher surgical conversion rate. The vNOTES approach reduced the postoperative exhaust time by approximately 9 h (95% confidence interval [CI]: −11.93, −5.57 h, p < .001) and the risk of postoperative analgesic drug use by 77% (odds ratio, 0.23; 95% CI: 0.10, 0.61, p = .023). Conclusion: vNOTES can shorten the exhaust time and duration of hospitalization, reduce postoperative pain, and avoid surface surgical scars in tubal pregnancy surgeries, consistent with the ERAS concept. However, more comprehensive preoperative evaluation of patients who choose vNOTES is required to reduce the occurrence of intraoperative conversion.Trial registration: ChiCTR2100053483

    Transvaginal natural orifice endoscopic surgery for ovarian cystectomy: a more suitable surgical approach for the day-care procedure

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    IntroductionAlthough previous studies have shown that vaginal natural orifice transluminal endoscopic surgery (vNOTES) has the advantages of causing less pain, faster recovery, and better concealment of surgical incisions, which aligns with the concept of the day-care procedure, this approach poses a greater risk of damaging adjacent organs (i. e., rectum and bladder) due to its anatomical specificity. Moreover, the day-care procedure may lead to relatively less preoperative evaluation and postoperative care. Hence, it is necessary to explore the safety and effectiveness of vNOTES for ovarian cystectomy in the day-care procedure, to provide a theoretical basis for the wider development of vNOTES surgery.Materials and methodsThis retrospective study included 131 patients at our hospital who underwent ovarian cystectomy from September 2021 to October 2022. Based on the surgical approach, patients were classified into transumbilical laparoendoscopic single-site surgery (LESS) and vNOTES groups. The patients' demographic characteristics and follow-up data were collected during the perioperative period and 1-month postoperatively.ResultsVaginal natural orifice transluminal endoscopic surgery has less postoperative exhaust time, a lower postoperative 6-hour pain score, and a lower incidence of analgesic drug use, with higher surgical conversion incidence. Multiple linear regression analysis showed that the surgical conversion, chocolate cyst, bilateral cyst, and pelvic adhesion increased the operation duration by ~43 (95% CI: 10.309, 68.152, p &lt; 0.001), 15 (95% CI: 6.342, 45.961, p = 0.036), 10 (95% CI: 3.07, 40.166, p = 0.019), and 8 (95% CI: 4.555, 26.779, p = 0.035) min, respectively. Interestingly, vNOTES decreased the operation duration by ~8.5 min (95% CI: −18.313, −2.699, p = 0.033).ConclusionVaginal natural orifice transluminal endoscopic surgery was equally safe and effective for ovarian cystectomy compared to LESS. vNOTES aligned with the concept of the day-care procedure due to its reduced postoperative pain, shorter exhaust time, and absence of scarring. However, surgeons should conduct a comprehensive preoperative evaluation and exclude patients suspected to have severe pelvic adhesions
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