Cefquinome Controlled Size Submicron Particles Precipitation by SEDS Process Using Annular Gap Nozzle

An annular gap nozzle was applied in solution enhanced dispersion by supercritical fluids (SEDS) process to prepare cefquinome controlled size submicron particles so as to enhance their efficacy. Analysis results of orthogonal experiments indicated that the concentration of solution was the primary factor to affect particle sizes in SEDS process, and feeding speed of solution, precipitation pressure, and precipitation temperature ranked second to fourth. Meanwhile, the optimal operating conditions were that solution concentration was 100 mg/mL, feeding speed was 9 mL/min, precipitation pressure was 10 MPa, and precipitation temperature was 316 K. The confirmatory experiment showed that D50 of processed cefquinome particles in optimal operating conditions was 0.73 μm. Moreover, univariate effect analysis showed that the cefquinome particle size increased with the increase of concentration of the solution or precipitation pressure but decreased with the increase of solution feeding speed. When precipitation temperature increased, the cefquinome particle size showed highest point. Moreover, characterization of processed cefquinome particles was analyzed by SEM, FT-IR, and XRD. Analysis results indicated that the surface appearance of processed cefquinome particles was flakes. The chemical structure of processed cefquinome particles was not changed, and the crystallinity of processed cefquinome particles was a little lower than that of raw cefquinome particles

Analysis on the dynamics of flexible drillstring under different drilling parameters

During the operation of the drill string, it displays a degree of flexibility. Simultaneously, its dynamic properties, influenced by complex stress conditions, manifest nonlinearity and uncertainty. A comprehensive investigation into the dynamics of flexible drill strings is imperative for deep well drilling. This paper presents a model that simulates random interactions between a flexible drill string and the borehole wall, simplifying the actual drill string model using analogous principles. Dynamic simulation software is utilized for analysis, and an indoor experimental setup has been established. The results reveal that with a constant weight on bit (WOB), higher drill string rotational speeds correlate with increased susceptibility to buckling deformation. Additionally, the critical time for deformation onset exhibits a nearly linear relationship with rotational speed. Maintaining a constant rotational speed, an increase in WOB enhances the likelihood of buckling deformation. The experimental findings suggest a correlation between the drill string’s rotation frequency and the WOB

Association of antenatal vitamin B complex supplementation with neonatal vitamin B12 status: evidence from a cluster randomized controlled trial

Purpose Evidence about the effect of maternal vitamin B12 supplementation on offspring’s vitamin B12 status is limited. The present interventional study sought to evaluate the association of antenatal vitamin B complex supplementation with neonatal vitamin B12 status. Methods In an ongoing cluster randomized controlled trial conducted in three rural counties in northwest China, pregnant women < 20 weeks of gestation were randomized to three treatment groups: blank control, iron supplements, or vitamin B complex supplements. All women were administered folic acid supplements during the periconceptional period. In a sub-study, we collected cord blood samples of 331 participants from the control or vitamin B complex groups in the Xunyi county from January 2017 to December 2017. Plasma concentrations of folate, vitamin B12, and homocysteine were measured. Linear mixed models with a random intercept for cluster were used to compare biochemical indexes between groups after controlling for covariates. Results Compared with newborns whose mothers were in the control group, newborns of the vitamin B complex-supplemented women had significantly higher cord plasma vitamin B12 (P = 0.001) and lower homocysteine concentrations (P = 0.043). The association of antenatal vitamin B complex supplementation with cord blood vitamin B12 concentrations appeared to be more pronounced among newborns with high folate status than those with low folate status (Pinteraction = 0.060). Conclusions Maternal vitamin B complex supplementation during pregnancy was associated with better neonatal vitamin B12 status in rural northwest China

Associations of B Vitamin-Related Dietary Pattern during Pregnancy with Birth Outcomes: A Population-Based Study in Northwest China

This study aimed to derive a maternal dietary pattern to explain the variation in B vitamins during pregnancy and to investigate this pattern in relation to birth outcomes. A total of 7347 women who gave birth to live newborns less than one year were included. Their dietary pattern during pregnancy was derived using the reduced-rank regression method with six B vitamins as response variables. Associations between dietary pattern score and birth weight, gestational age at delivery, birth weight Z score, low birth weight, preterm, and small-for-gestational-age (SGA) were estimated using generalised linear mixed models. We identified a high B-vitamin dietary pattern characterised by high intakes of animal foods, vegetables, fungi and algae, legumes, and low intakes of oils and cereals. Women in the highest quartile of this pattern score had newborns with a 44.5 g (95% CI: 13.8, 75.2 g) higher birth weight, 0.101 (95% CI: 0.029, 0.172) higher birth weight Z score, and 27.2% (OR: 0.728; 95% CI: 0.582, 0.910) lower risk of SGA than those in the lowest quartile. Our study suggested that adherence to the high B-vitamin dietary pattern during pregnancy was associated with a higher birth weight and a lower risk of SGA

A mathematical model of plasmid-carried antibiotic resistance transmission in two types of cells

Antibiotic resistance is a significant public health problem. When resistance genes are being carried on plasmids, the spread can be greatly accelerated. In this paper, the transmission of antibiotic resistance in two types of cells is discussed. A mathematical model is established to describe the dynamics of the transmission of plasmids. The effects of different parameters on the stable solution and sensitivity analysis are studied by numerical simulation. The conclusions show that the concentration of antibiotics must reach a certain level to kill the pathogenic bacteria. If the concentration of antibiotics is not high to a certain extent, the treatment becomes ineffective. If the cost of cells carried on plasmids and the rate of resistance plasmids segregation too high, the drug-resistant cells will gradually die out in the system. The rate of horizontal transfer of resistance plasmids is directly related to the spread of drug resistance. With the increase in the horizontal transfer rate of resistance plasmids, cells in the body gradually turn into cells with antibiotic resistance, which causes substantial difficulties in the treatment of diseases

Applications of Crowdsourcing in Evidence Synthesis: A Case Study of Cochrane Crowd

[Purpose/Significance] Evidence-informed decision-making is a means to bridge the gap between research and policy and evidence synthesis has become an important tool for evidence-based decision-making in many fields. However, evidence synthesis is resource-intensive, especially when it comes to scientific knowledge on complex issues. The efficiency of evidence synthesis currently cannot meet the needs of decision makers. Crowdsourcing is seen as a potential way to improve the productivity of evidence synthesis. At present, the research and practice on the applications of crowdsourcing in evidence synthesis is still in its infancy. This study takes the application of crowdsourcing in the Cochrane Crowd citizen science project as an example to summarize the practical applications of crowdsourcing in evidence synthesis. The comprehensive analysis of the application mechanism of crowdsourcing in Cochrane Crowd project will provide certain reference and inspiration for the use of crowdsourcing in evidence synthesis, so as to improve the production efficiency of evidence synthesis and provide timely and powerful scientific information for evidence-based decision-making. [Method/Process] The application mechanism of crowdsourcing in the Cochrane Crowd citizen science project was analyzed from five dimensions: crowdsourcer, volunteers, crowdsourcing task, Cochrane Crowd platform and effectiveness evaluation, using literature research, network investigation, case analysis and other methods. Cochrane Crowd provides an easy-to-use interface for contributors to engage volunteers to participate and design , in addition to task-focused learning activities, diverse ways of accessing tasks, interactive online training modules and feedback mechanisms to improve the likelihood of volunteers' performing tasks correctly. At the same time, an agreement algorithm is provided at the platform level to aggregate the crowd classification results, which further improves the possibility of correct classification of records. In addition, the platform has used the records identified by the crowd to build a machine-learning model called as RCT classifier which can predict how likely a new citation is to be described an RCT to reduce the manual burden. [Results/Conclusions] Crowdsourcing is an effective method to improve the efficiency of evidence synthesis and shorten the production cycle. With comprehensive participant training and appropriate quality control mechanisms, it is possible to produce high quality crowdsourcing results that meet the "gold standard" of evidence synthesis. In order to motivate volunteers to participate and promote continued engagement, participants are suggested to be provided with clear goals, clear tasks, and timely feedback or rewards. Interest and activity in introducing crowdsourcing into evidence synthesis is growing rapidly, and new tools and platforms to facilitate crowdsourcing also need to be further developed as researchers from different disciplines use crowdsourcing in the evidence synthesis projects. In the future, the application of crowdsourcing in evidence synthesis in different fields and in different stages of evidence synthesis should be further studied

Population Dynamics of Patients with Bacterial Resistance in Hospital Environment

During the past decades, the increase of antibiotic resistance has become a major concern worldwide. The researchers found that superbugs with new type of resistance genes (NDM-1) have two aspects of transmission characteristics; the first is that the antibiotic resistance genes can horizontally transfer among bacteria, and the other is that the superbugs can spread between humans through direct contact. Based on these two transmission mechanisms, we study the dynamics of population in hospital environment where superbugs exist. In this paper, we build three mathematic models to illustrate the dynamics of patients with bacterial resistance in hospital environment. The models are analyzed using stability theory of differential equations. Positive equilibrium points of the system are investigated and their stability analysis is carried out. Moreover, the numerical simulation of the proposed model is also performed which supports the theoretical findings

Threshold Strategy for Nonsmooth Filippov Stage-Structured Pest Growth Models

In order to control pests and eventually maintain the number of pests below the economic threshold, in this paper, based on the nonsmooth dynamical system, a two-stage-structured pest control Filippov model is proposed. We take the total number of juvenile and adult pest population as the control index to determine whether or not to implement chemical control strategies. The sliding-mode domain and conditions for the existence of regular and virtual equilibria, pseudoequilibrium, boundary equilibria, and tangent points are given. Further, the sufficient condition of the locally asymptotic stability of pseudoequilibrium is obtained. By numerical simulations, the local bifurcations of the equilibria are discussed. Our results show that the total number of pest populations can be successfully controlled below the economic threshold by taking suitable threshold policy