A novel solid-phase extraction (SPE) adsorbent for simultaneous extraction of atrazine (ATZ) and its metabolites, deisopropylatrazine (DIA) and deethylatrazine (DEA) from environmental water samples was prepared. Polyacrylonitrile nanofibers (PAN NFs) mat was prepared via electrospinning, and was further functionalized to obtain polypyrrole modified polyacrylonitrile nanofibers (PPy-PAN NFs) mat, hydrazine modified polyacrylonitrile nanofibers (NH2-PAN NFs) mat and carboxyl modified polyacrylonitrile (COOH-PAN NFs) mat. The results showed that the adsorption capacity of COOH-PAN NFs mat was better than other three NFs mats in both static (2.0 mg/g) and dynamic (0.19 mg/g) experiments. Meanwhile, the runoff ratios of COOH-PAN NFs mat were the lowest (less than 30.0％) in the adsorption of three analytes, especially for high polar analytes, which showed that the hydrogen bond between carboxyl groups and analytes was the main interactive force. A combination of mat-based SPE and high performance liquid chromatography-diode array detection was further established for determination of 3 analytes in environmental water samples. The recoveries were 81.4％-120.3％ and the limits of detection were 0.12 ng/mL for DIA, 0.09 ng/mL for DEA and ATZ, respectively.

A sensitive colorimetric method for the detection of copper ions (Cu2+) was developed based on the surface modification of silver/platinum nanoclusters (Ag/Pt NCs) and regulation of peroxidase-like activity. It was found that 3-mercaptopropionic acid (MPA) could inhibit the catalytic ability of Ag/Pt NCs; however, it lost the inhibition toward catalytic ability of Ag/Pt NCs after oxidized by oxygen through the catalysis of Cu2+. On the basis of this, a colorimetric method was developed for the detection of Cu2+ through measuring the colorimetric signal variation of the TMB-H2O2 reaction. This method exhibited high sensitivity and selectivity toward Cu2+ over a panel of other metal ions. The linear range was 10-100 nmol/L and the detection limit was 5.0 nmol/L (3σ). The above method was also applied to detect real water samples and spiked samples, and the results demonstrated that this method was simple with low cost.

Objective:To learn about the knowledge and practice of iodine deficiency disorders (IDD) prevention and control among main caregivers of pregnant women in trimester and its related influencing factors, so as to provide a scientific basis for effectively improving the iodine nutrition level of pregnant women.Methods:In April 2020, using the stratified sampling method, 2 districts and counties were selected in the urban, suburban and rural areas of Hangzhou City, respectively, and 5 maternal and child health care institutions were selected as the survey sites in each district and county according to the five directions of East, West, South, North and Middle. A face-to-face questionnaire investigation was used to investigate the knowledge and practice of IDD prevention and control among main caregivers of pregnant women.Results:Totally 601 caregivers of pregnant women were investigated. Among them, 68.9% (414/601) knew that eating iodized salt was the best way to prevent IDD. However, 15.0% (90/601) thought that eating seafood was the best way to prevent IDD. And 41.9% (252/601) caregivers of pregnant women would actively purchase iodine-rich food for cooking, and 63.6% (382/601) would choose iodized salt. There were statistically significant differences in the knowledge and practice of IDD prevention and control among caregivers of pregnant women in urban, suburban and rural areas ( P < 0.05). And 50.3% (87/173) male caregivers would actively purchase iodine-rich food for cooking, which was higher than that of female caregivers [38.6% (165/428)], the difference was statistically significant (χ 2 = 6.97, P = 0.008). There was a statistically significant difference between the caregivers of pregnant women of different ages in actively purchasing iodine-rich food for cooking (χ 2 = 12.61, P = 0.013). And there were statistically significant differences between the caregivers of pregnant women with different educational levels in actively purchasing iodine-rich food for cooking and choosing iodized salt (χ 2 = 29.34, 39.42, P < 0.001). Conclusions:The awareness of knowledge about IDD prevention and control and the formation of prevention and control behavior among caregivers of pregnant women in Hangzhou City are poor. Active education of caregivers of pregnant women should be strengthened to promote maternal and infant health.

OBJECTIVE: To compare the effectiveness and sensitivity of entropy and regional homogeneity (ReHo) for identifying irritable bowel syndrome (IBS) based on functional magnetic resonance imaging (fMRI). METHODS: Voxel-based approximate entropy (ApEn) was calculated based on findings of resting fMRI of 54 patients with IBS and 54 healthy control subjects. Feature selection was performed using independent sample -test, and support vector machine was then used to classify and identify different groups. The classification performance obtained from ApEn was compared with that from ReHo. RESULTS: Significant differences between the two groups were found in the left triangle part of inferior prefrontal gyrus, right angular gyrus of the inferior parietal lobule, left inferior temporal gyrus, left middle temporal gyrus, left lingual gyrus, bilateral middle occipital gyrus and bilateral superior occipital gyrus for ReHo ( < 0.05), and in the bilateral postcentral gyrus, right precentral gyrus, right inferior temporal gyrus, bilateral middle temporal gyrus and left superior occipital gyrus for ApEn ( < 0.05). ApEn consistently showed better performance than ReHo regardless of the variations in the number of features. The classification accuracy, specificity and sensitivity of ApEn were 93.5185%, 90.7407% and 96.2963%, respectively, as compared with 86.1111%, 85.1852% and 87.037% of ReHo. CONCLUSIONS Entropy analysis based on fMRI can be more sensitive and effective than ReHo for identification of IBS.
Brain ; diagnostic imaging ; Brain Mapping ; Case-Control Studies ; Entropy ; Humans ; Irritable Bowel Syndrome ; diagnostic imaging ; Magnetic Resonance Imaging

OBJECTIVE: To explore the application value of rectal prolapse constipation balloon in single auxiliary defecation. METHODS: Forty-one patients with moderate or severe rectocele were treated with a rectocele constipation balloon through the vagina. The defecography and VAS scores were compared before and after implantation. RESULTS: There was a significant difference between the anorectal angle, rectocele, and VAS scores before and after intervention in defecography (<0.01). CONCLUSIONS A single assisted defecation of the rectocelicular constipation balloon is feasible.
Constipation ; diagnosis ; Defecation ; Defecography ; instrumentation ; Female ; Humans ; Rectal Prolapse ; Rectocele

Objective:To achieve rapid and accurate detection of trace uranium in drinking water by analyzing the factors influencing the accuracy of uranium measurement in drinking water using ultraviolet fluorescence method and by evaluating the uncertainty in measurement.Methods:The influence of acidity, Fe 3+ and Mn 2+ contents on the analitical result were studied to optimize the measurement conditions. The accuracy of the measurement method was verified in 7 laboratories. By studying the errors introduced in the process of standard preparation, sample pretreatment and measurement, the sources of uncertainty were analyzed and the uncertainty was synthesized. Results:At pH 1-11 in aqueous solution, the linear regression coefficient of the standard curve was greater than 0.995, which was in line with the linear measurement range of the instrument. At pH 12 or so, the linear regression coefficient was 0.761, which could not meet the measurement requirements. At pH<3 or pH>10, the increase in fluorescence count was lower, which might increase the measurement error. At Fe 3+ concentration ≥15 mg/L, a large deviation occurred in measurement value that could affect seriously measurement result. At Mn 2+ concentration ≥ 1.6 mg/L, the sample produced white precipitation, which could affect the measurement accuracy. Three spiked water samples with different concentrations were determined in 8 laboratories. Each water sample was measured six times in parallel. The relative standard uncertainty of the result were 6.42×10 -2, 4.48×10 -2 and 5.26×10 -2 μg/L, and the expanded uncertainties were 0.03, 0.06 and 0.12 μg/L( k=2), respectively. Conclusions:The optimum conditions for the determination of uranium in water using this method pH were in samples 3-10, the concentration of Fe 3+ less than 15 mg/L, and the concentration of Mn 2+ less than or equal to 1.6 mg/L. The main sources of uncertainty in the measurement of uranium in water using ultraviolet fluorescence method arise from the repeated measurement error and the volume of added standard solution.

Objective: To investigate the effect of Micro-lecture combined with Simbaby teaching model in the practical teaching of neonatology for undergraduates. Methods: A total of 160 five-year medical undergraduates from grade 2013 to grade 2015 were divided into group A (the control group) and group B (the experimental group), with 40 male students and 40 female students in each group. Students in group B received Micro-lecture combined with Simbaby teaching model, while students in group A received traditional teaching method. In group A, teachers adopted traditional teaching method with the use of common teaching models, then students practiced on these models following the demonstrations from teachers. In group B, students previewed the contents before class in micro-lecture, then teachers made Simbaby to be used as case models and explained to the students as how to use the model in actual class. Students made diagnosis and gave treatment to the Simbaby after physical examination. At last, teaching effects were evaluated by questionnaire survey and theoretical test. The SPSS 24.0 was used to conduct t-test and chi square test. Results: The average scores of theoretical test (88.40±9.40) and skill test in group B (79.53±8.84) were significantly higher than those in group A (84.86±9.50) and (72.35±9.70), with statistically significant differences (P<0.05). The results of Questionnaires showed that learning enthusiasm and initiative, clinical operation skills and clinical thinking ability in group B were significantly better than in group A (P<0.05). However, improvement of the awareness for team cooperation in the two groups had no statistically significant difference (P>0.05). Conclusion Micro-lecture combined with Simbaby teaching model can help students comprehend the basic theories of neonatal disease and improve their clinical operation skills, self-learning ability and clinical thinking ability, which is worth to be promoted in neonatal clinical teaching.

Objective:To study the influence of source thickness and counting efficiency calibration on the measurement of gross alpha activity in water.Methods:241Am and natural uranium reference materials were spiked in drinking water to prepare source on a planchet with different thickness, for counting alpha activity on the planchet. Results:The effective thickness measured by spiking 241Am or uranium standard solution in water sample was consistent with the empirical value of 4 mg/cm 2. The alpha counting rate was in a linear increase trend from 2A-5A mg/cm 2 and was basically stable and no longer increase when thickness was higher than 10A mg/cm 2 (A was area of planchet). The result calculated by effective thickness method and thick source method were in good agreement when thickness was 10A mg/cm 2. Conclusions:In order to reduce the deviation of gross alpha counting rate caused by the source thickness and counting efficiency calibration, the source thickness is recommended to be 10A mg/cm 2.