Evaluation of formic acid toxicity to subterranean termite, Reticulitermes chinensis Snyder

This study examined formic acid contact and fumigation toxicity to R. chinensis in the laboratory. In the contact toxicity bioassay, the LD50 values ranged from 267.86 to 287.68 μg adult-1 for workers, 279.09 μg adult-1 for alates (male and female) and 223.08 μg adult-1 for soldiers after 24 h, respectively. In the fumigation bioassays, the LC50 values ranged from 0.84 to 1.08 μg ml-1 for workers, 1.19 μg ml-1 for alates (male and female) and 0.57 μg ml-1 for soldiers after 24 h, respectively. At the concentration of 2.50 μg ml-1, the KT50 value of formic acid ranged from 25.38 to 34.75 min for workers, from 42.21 to 45.62 min for alates (male and female), from 32.18 to 36.37 min for soldiers. Although formic acid was significantly less toxic to subterranean termite than bifenthrin, but higher toxic to many other pest insects. The findings of this study provide important confirmation of formic acid with fumigation toxicity against termite. It may be worth investigating the use of formic acid for managing subterranean termite

The Mechanism Study of Vortex Tools Drainage Gas Recovery of Gas Well

The liquid loading of gas well is an important issue in deep exploitation of natural gas. The technic of vortex drainage has good prospects because the tool construction and construction work is simple, the technic is environmental and efficient. Currently, the mechanism for the vortex drainage and the theory of fluid motion are still missing. Therefore, in order to further understand the downhole flow field, verify drainage mechanism and select best working conditions, based on computational fluid dynamics and mixture model of multiphase flow through Fluent, the study established a three-dimensional structural model of vortex tools and the numerical simulation has been done. By monitoring the wellhead and the radial distribution of the liquid content and observing the state of the gas-liquid flow and the path line, the study analyzed the influence on gas well flow field by vortex tool. The study revealed the working mechanism of vortex tools to facilitate understanding the nature of the vortex drainage process, guide how to select the preferred process conditions and provide theoretical basis for the application and the dynamics simulation of vortex drainage technology.Key words: The liquid loading of gas well; Vortex drainage; Multiphase flow; Numerical simulatio

CagA-positive Helicobacter pylori may promote and aggravate scrub typhus

Helicobacter pylori (H. pylori) infection may alter the host’s resistance to tsutsugamushi disease pathogens through the Th1 immune response, leading to potential synergistic pathogenic effects. A total of 117 scrub typhus cases at Beihai People’s Hospital and affiliated hospitals of Youjiang University for Nationalities and Medical Sciences were studied from January to December 2022, alongside 130 healthy individuals forming the control group. All participants underwent serum H. pylori antibody testing. The prevalence of H. pylori infection was significantly higher among scrub typhus patients (89.7%) compared to healthy individuals (54.6%) (p < 0.05). Moreover, type I H. pylori infection was notably more prevalent in scrub typhus cases (67.5%) compared to healthy individuals (30%) (p < 0.05). Multifactorial analysis demonstrated type I H. pylori infection as an independent risk factor for scrub typhus (adjusted odds ratio: 2.407, 95% confidence interval: 1.249–4.64, p = 0.009). Among scrub typhus patients with multiple organ damage, the prevalence of type I H. pylori infection was significantly higher (50.6%) than type II H. pylori infection (15.4%) (χ2 = 4.735, p = 0.030). These results highlight a higher incidence of H. pylori infection in scrub typhus patients compared to the healthy population. Additionally, type I H. pylori strain emerged as an independent risk factor for scrub typhus development. Moreover, individuals infected with type I H. pylori are more susceptible to multiple organ damage. These findings suggest a potential role of H. pylori carrying the CagA gene in promoting and exacerbating scrub typhus

Comparison of pain intensity and impacts on oral health-related quality of life between orthodontic patients treated with clear aligners and fixed appliances: a systematic review and meta-analysis

Abstract Objective This study aimed to compare the pain intensity and impacts on oral health-related quality of life (OHRQoL) between orthodontic patients treated with clear aligners (CAs) and fixed appliances (FAs). Methods A systematic search was conducted up to December 2022 using PubMed, Web of Science, Cochrane Central Register of Controlled Trials, and Embase. Randomized controlled trials (RCTs) and prospective non-randomized controlled trials (non-RCTs) comparing pain intensity or OHRQoL between patients treated with CAs and FAs were included. The risk of bias (RoB) of individual studies was evaluated using the Cochrane RoB tool 2.0 and ROBINS-I tool for RCTs and non-RCTs, respectively. Further, meta-analyses were separately conducted for each included study using the total oral health impact profile (OHIP)-14 and visual analog scale (VAS) scores to evaluate OHRQoL and pain intensity, respectively. Results Overall, 12 studies (5 RCTs and 7 non-RCTs) were included in the study. Subgroup analyses conducted according to the total OHIP-14 scores revealed that patients treated with CAs had higher OHRQoL at 1 week, 1 month, and 6 months of the treatment. Meanwhile, subgroup analyses conducted according to the VAS scores revealed that pain levels were lower in the CA group only at 3 and 4 days of the treatment. Conclusions Patients treated with clear aligners had higher OHRQoL than those treated with fixed appliances during orthodontic treatment. However, OHRQoL appeared to be similar between the two groups at the end of the treatment. Moreover, patients treated with clear aligners experienced lesser pain than those treated with fixed appliances on the third and fourth day after the initial treatment. The difference in pain intensity between the two treatment modalities was not noted at other time points

Evaluation of formic acid toxicity to subterranean termite, Reticulitermes chinensis Snyder

This study examined formic acid contact and fumigation toxicity to R. chinensis in the laboratory. In the contact toxicity bioassay, the LD50 values ranged from 267.86 to 287.68 μg adult-1 for workers, 279.09 μg adult-1 for alates (male and female) and 223.08 μg adult-1 for soldiers after 24 h, respectively. In the fumigation bioassays, the LC50 values ranged from 0.84 to 1.08 μg ml-1 for workers, 1.19 μg ml-1 for alates (male and female) and 0.57 μg ml-1 for soldiers after 24 h, respectively. At the concentration of 2.50 μg ml-1, the KT50 value of formic acid ranged from 25.38 to 34.75 min for workers, from 42.21 to 45.62 min for alates (male and female), from 32.18 to 36.37 min for soldiers. Although formic acid was significantly less toxic to subterranean termite than bifenthrin, but higher toxic to many other pest insects. The findings of this study provide important confirmation of formic acid with fumigation toxicity against termite. It may be worth investigating the use of formic acid for managing subterranean termite

Additional file 1 of Comparison of pain intensity and impacts on oral health-related quality of life between orthodontic patients treated with clear aligners and fixed appliances: a systematic review and meta-analysis

Additional file 1. Database and search strategy

Applicable Conditions of Room-and-Pillar Mining Goaf Treatment Methods under a Traffic Load

The disturbance depth of traffic load has a direct impact on the stability of a room-and-pillar mining goaf. To quantitatively calculate the relationship between the traffic load disturbance depth and influencing factors, 49 groups of horizontal combinations of different influencing parameters are designed in this study, based on the orthogonal experimental design method. Midas GTS is used to simulate and obtain the corresponding traffic load disturbance depth data. A multivariate linear regression analysis of the traffic load disturbance depth is conducted, and a regression formula for calculating the traffic load disturbance depth is established. According to the traffic load disturbance depth, goaf depth, and the stability of the roof, coal pillar, and base plate under traffic load conditions, a judgment flow of the room-and-pillar mining goaf treatment method under traffic load conditions is established, and it is applied to the reconstruction and expansion project of the Jixi section of the Dan-A national highway. The results show that a geogrid can be used for treatment purposes when the traffic load disturbance depth is 1.5 times lower than the depth of the room-and-pillar mining goaf, or when the traffic load disturbance depth is 1.5 times greater than the depth of the room-and-pillar mining goaf but the roof, coal pillar, and base plate are stable. Additionally, grouting is needed for treatment in other cases. The results of this study can provide a scientific basis for the selection of treatment methods for room-and-pillar mining goafs underlying highways in the future. The results are of great significance in the field of engineering for the safety measures concerning highway room-and-pillar mining goafs

Applicable Conditions of Room-and-Pillar Mining Goaf Treatment Methods under a Traffic Load

The disturbance depth of traffic load has a direct impact on the stability of a room-and-pillar mining goaf. To quantitatively calculate the relationship between the traffic load disturbance depth and influencing factors, 49 groups of horizontal combinations of different influencing parameters are designed in this study, based on the orthogonal experimental design method. Midas GTS is used to simulate and obtain the corresponding traffic load disturbance depth data. A multivariate linear regression analysis of the traffic load disturbance depth is conducted, and a regression formula for calculating the traffic load disturbance depth is established. According to the traffic load disturbance depth, goaf depth, and the stability of the roof, coal pillar, and base plate under traffic load conditions, a judgment flow of the room-and-pillar mining goaf treatment method under traffic load conditions is established, and it is applied to the reconstruction and expansion project of the Jixi section of the Dan-A national highway. The results show that a geogrid can be used for treatment purposes when the traffic load disturbance depth is 1.5 times lower than the depth of the room-and-pillar mining goaf, or when the traffic load disturbance depth is 1.5 times greater than the depth of the room-and-pillar mining goaf but the roof, coal pillar, and base plate are stable. Additionally, grouting is needed for treatment in other cases. The results of this study can provide a scientific basis for the selection of treatment methods for room-and-pillar mining goafs underlying highways in the future. The results are of great significance in the field of engineering for the safety measures concerning highway room-and-pillar mining goafs