Investigation of aqueous Fe(III) and Mn(II) removal using dolomite as a permeable reactive barrier material.

Iron (Fe) and manganese (Mn) are the most frequently detected heavy metals in the soil and groundwater near municipal landfill sites. Natural calcium-carbonate-based materials, such as dolomite, effectively remove metal ions and are suitable as reactive materials for permeable reactive barriers (PRBs). However, multiple heavy metals usually coexist in contaminated groundwater, the effectiveness and competitive precipitation mechanisms in the removal of Fe(III) and Mn(II) are unclear. In this study, we investigated the efficiency and influencing factors of the removal of single and coexisting Fe(III) and Mn(II) by dolomite through experimental batch and column tests, property characterization, and PHREEQC simulations. Dolomite with 1.18-2.36 mm particle size showed the best removal efficiency for Fe(III) and Mn(II) through precipitation. Fe(III) was preferentially precipitated by dolomite with higher removal efficiency, attributed to the lower solubility product (Ksp) of iron precipitates. Compared with Fe(III), Mn(II) was precipitated conditionally, and the removal efficiency was restricted by the concentration of Fe(III) in the system. Considering the application of PRB in the field, dolomite would be effective for the remediation of coexisting heavy metals with lower precipitate Ksp. The half-time of Mn(II) removal could serve as a reference for PRB thickness designs if the target metal contaminants were in a similar concentration range as Fe(III) and Mn(II). Additionally, the PRB performance could be affected by the reduction of hydraulic permeability induced by precipitation, and the fine precipitates migrating from PRB might affect downstream groundwater quality.

Application of multi-slice spiral CT and abdominal ultrasound in clinical diagnosis of acute appendicitis in children / 中国基层医药

Objective:To investigate the application value of multi-slice spiral CT and abdominal ultrasound methods in the clinical diagnosis of acute appendicitis in children.Methods:We included 50 children patients who were pathologically diagnosed with acute appendicitis by the Department of Surgery, Dongyang Maternal and Child Health Hospital from August 2016 to August 2019. Before surgery, all patients underwent multi-slice spiral CT and abdominal ultrasound examinations. We recorded the time taken to complete multi-slice spiral CT and abdominal ultrasound examinations. Taking pathological results as the diagnosis criteria, we also calculated the coincidence rate of each imaging method.Results:The time we took to complete multi-slice spiral CT examination was shorter than that for abdominal ultrasound examination [(13.34 ± 3.86) minutes vs. (23.45 ± 4.77) minutes, t = 11.65, P < 0.05]. The coincidence rate of multi-slice spiral CT in identifying acute simple appendicitis, acute phlegmonous appendicitis, and acute gangrenous appendicitis was 95.24%, 95.00%, and 100.0%, respectively, and it was 71.73%, 70.00%, 88.89%, respectively for abdominal ultrasound examination. The coincidence rates in identifying acute simple appendicitis, acute phlegmonous appendicitis, and acute gangrenous appendicitis were significantly different between multi-slice spiral CT and abdominal ultrasound examinations ( χ2 = 4.29, 4.33, 1.06, all P < 0.05). Conclusion:Compared with abdominal ultrasound, multi-slice spiral CT is easier to operate, takes a shorter time in manipulation, provides more distinct images, and has a higher coincidence rate. Therefore, multi-slice spiral CT is of great diagnostic value for acute appendicitis in children.

Expression and clinical significance of CD8 +CD28-T lymphocytes in the patients with endometriosis complicating with pelvic fluid / 中国医师杂志

Objective To explore the expression and clinical significance of CD 8 +CD28 -T lymphocytes in the patients with endometriosis ( EMT) complicating with pelvic fluid .Methods Eighty patients with endometriosis complicating with pelvic fluid ( ca-ses of ⅠtoⅣwere 15, 12, 22, and 31, respectively) were enrolled.The peripheral blood as well as the pelvic fluid were collected and flow cytometry was applied to detect the frequencies of CD 8 +CD28 -T lymphocytes and their intracellular cytokines , including transforming growth factor β1 (TGF-β1) and interleukin 10 (IL-10).Twenty health women with the same range of age were enrolled as the control group .Results Compared with the control ones , the frequencies of peripheral blood CD 8 +CD28 -T lymphocytes , TGF-β1, and IL-10 of the EMT subjects were increased significantly (all P Ⅲ>Ⅱ>Ⅰand the difference between every two of the Ⅰ~Ⅳgroups was significant (all P Ⅲ>Ⅱ>Ⅰ.Moreover, the difference of pelvic fluid TGF-β1 between any two groups was more apparent compared with CD 8 +CD28 -T lymphocytes and IL-10 ( P <0.05 ) .Spearman correlation analysis showed that any one of CD8 +CD28 -T lymphocytes, TGF-β1, and IL-10 positively correlated with any stage of ⅠtoⅣ( rs =0.791, 0.753,0.726 and all P <0.05).Conclusions CD8 +CD28 -T lymphocytes, TGF-β1, and IL-10 were closely related to the stages and could be the negative roles in the pathogenesis of EMT .TGF-β1 played a vital role in the formation of pelvic fluid .