Effects of Chelating Surfactants on Competitive Adsorption of Lead and Zinc on Loess Soil

The study of competitive adsorption of heavy metals on soil is important for heavy metals contaminated soil remediation. However, there have been few studies on the impact of desorption reagents on heavy metal adsorption in soil. Batch adsorption studies were used to investigate the competitive adsorption mechanism of two heavy metals, Pb and Zn, on a loess soil in the presence of a new chelating surfactant, sodium N-lauroyl ethylenediamine triacetate (LED3A). Results showed that competitive adsorption equilibria of Pb and Zn were reached at 3 and 10 h, respectively. The maximum equilibrium adsorption capacities were 19.55 and 18.35 g.kg-1, respectively. LED3A affected the competitive adsorption kinetics of Pb and Zn by increasing the change in external mass transfer and reducing the change in internal mass transfer. LED3A reduced Pb and Zn adsorption capacities onto the soil through competitive chelation of the heavy metals. The heavy metal chelating ability of LED3A was higher for Zn than for Pb. When its concentration was larger than 5 g.L-1, LED3A showed a significant effect on the competitive adsorption of Pb and Zn. In the competitive system, the effect of Pb concentration on the Zn adsorption capacity was greater than the effect of Zn concentration on the Pb adsorption capacity. LED3A weakened the effect of Pb concentration and enhanced the effect of Zn concentration. LED3A showed a significant potential for efficiently leaching remediation of Pb and Zn co-contaminated soil.

Effect of Wheat Straw Biochar on Thermophysical Properties of Loessial Soil

Soil thermophysical properties are the key factors affecting the internal heat balance of soil. In this paper, biochars (BC300, BC500 and BC700) were produced with wheat straw at the temperatures of 300, 500 and 700°, respectively. The effects of biochar amendment at the rates of 0%, 1%, 3%, and 5% on the thermophysical properties (thermal conductivity, heat capacity, and thermal diffusivity) of a loessial soil were investigated with and without water content respectively. Although the bulk density of soil significantly decreased with biochar amendment, due to enhancing soil porosity and organic matter content, the thermophysical properties of soil did not change largely with biochar amendment rate and pyrolysis temperature. Water content exhibited significant effects on the thermophysical properties of soils added with biochars, where the thermal conductivity and heat capacity of soil were linearly proportional to water content, the thermal diffusivity initially increased and then decreased with the increase of water content. In the meanwhile, there was no significant correlation between the biochar amendment rate or pyrolysis temperature and thermophysical properties. The results show that water content should be mainly concerned as a factor when the internal heat balance of loess soil is evaluated, even though the soil is amended with biochar.

[Consideration and prevention of the aerosol transmission of 2019 novel coronavirus]

This article was published ahead of print on the official website of Chinese Journal of Ophthalmology on March 14, 2020. Novel coronavirus pneumonia broke out and spread to the whole nation since December 2019. The fight against the virus is now at a critical stage. Previous epidemiological investigations and animal experiments suggested aerosol could perform as a virus transmitter. Based on the clinical observation, the possibility of aerosol transmission of 2019 novel coronavirus has aroused much attention. This article focuses on the feature of aerosol transmission and the pathogens involved in. We analyze the possibility of aerosol transmission of the novel coronavirus. Relevant strategies for preventing novel coronavirus pneumonia are established for the medical personnel and general public during their work or daily life. (Chin J Ophthalmol, 2020, 56:653-656).

[Diagnostic values of BRAF(V600E) mutation analysis and Bethesda system for reporting thyroid cytopathology in thyroid nodules with TIRADS 4 and 5]

Objective: To evaluate the diagnostic efficacies of BRAF(V600E) testing and Bethesda system for reporting thyroid cytopathology (BSRTC) in thyroid nodules with thyroid imaging reporting and data system (TIRADS) category 4 and 5. Methods: A total of 187 thyroid nodules in 187 patients underwent the examinations of ultrasound-guided fine needle aspiration cytology (FNAC) and BRAF(V600E) mutation were analyzed retrospectively. Receive operating characteristic (ROC) curve was used to investigate the diagnostic values of both methods and the clinical application of BRAF(V600E) combined with BSRTC was evaluated. SPSS17.0 software was used to analyze the data. Results: Among 187 thyroid nodules, 123 were malignant nodules confirmed with histopathological examination and 64 benign nodules determined by FNAC, histopathological examination, or long-term follow-up. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of BRAF(V600E) test were better than those of BSRTC [69.1%, 98.4%, 98.8%, 62.4%(χ(2)=77.3, P=0.000) vs 62.6%, 93.8%, 95.1%, 56.6%(χ(2)=54.4, P=0.000)]. While the sensitivity, specificity, PPV and NPV of the combined test of BRAF(V600E) and BSRTC for diagnosis of malignant thyroid nodules were 87.8%, 92.2%, 95.6%, 79.7%(χ(2)=112.6, P=0.000), respectively. The area under the ROC curve for the combined test was higher than that for each of tests (0.900 vs 0.858 or 0.838). Conclusions: The combined test of BRAF(V600E) mutation and BSRTC has a higher diagnostic efficacy for malignant thyroid nodules compared with BRAF(V600E) mutation or BSRTC alone.

[Prediction of occult carcinoma in contralateral nodules based on the ultrasonic features of unilateral papillary thyroid carcinoma]

Objective: To investigate the occurrence of occult carcinoma in contralateral lobes based on the ultrasonic features of unilateral papillary thyroid carcinoma. Methods: The study included 202 consecutives cases of unilateral papillary thyroid carcinoma with benign nodules in the contralateral lobe identified by preoperative ultrasound or fine-needle aspiration from June 2014 to December 2015. All patients received total thyroidectomies, and with postoperative pathological examination they were divided into two groups, one including 60 cases with positive occult cancer and another one consisting of 142 cases with negative occult cancer. Univariate and multivariate analyses were performed to analyze the sonographic features of unilateral papillary thyroid carcinoma relevant to the occurrence of occult carcinoma in the contralateral nodules. Results: Univariate analysis indicated occult carcinoma in the contralateral lobes was associated with Hashimoto's thyroiditis(χ(2)=3.955, P=0.047), unclear border (χ(2)=4.375, P=0.036)and multifocality in the ipsilateral(χ(2)=7.375, P=0.007), but not with tumors maximum size, location, A/T, shape, internal structure, internal echo, acoustic halo, calcification, capsular invasion and blood flow signal in the lobe with carcinoma on another side. Multivariate analysis showed unclear border (OR=2.727, P=0.010) and multifocality in the ipsilateral(OR=2.807, P=0.005)of carcinoma were independent predictive factor for contralateral occult PTC. Conclusions: Unclear border and multifocality of PTC in the ipsilateral were closely relevant to the occurrence of occult carcinoma in the contralateral nodules.

Predicting the aquatic toxicity mode of action using logistic regression and linear discriminant analysis

The paper highlights the use of the logistic regression (LR) method in the construction of acceptable statistically significant, robust and predictive models for the classification of chemicals according to their aquatic toxic modes of action. Essentials accounting for a reliable model were all considered carefully. The model predictors were selected by stepwise forward discriminant analysis (LDA) from a combined pool of experimental data and chemical structure-based descriptors calculated by the CODESSA and DRAGON software packages. Model predictive ability was validated both internally and externally. The applicability domain was checked by the leverage approach to verify prediction reliability. The obtained models are simple and easy to interpret. In general, LR performs much better than LDA and seems to be more attractive for the prediction of the more toxic compounds, i.e. compounds that exhibit excess toxicity versus non-polar narcotic compounds and more reactive compounds versus less reactive compounds. In addition, model fit and regression diagnostics was done through the influence plot which reflects the hat-values, studentized residuals, and Cook's distance statistics of each sample. Overdispersion was also checked for the LR model. The relationships between the descriptors and the aquatic toxic behaviour of compounds are also discussed.

Color Doppler twinkling artifact in fetuses with echogenic intracardiac foci: echocardiographic observation and clinical significance

OBJECTIVE

To evaluate echocardiographic characteristics and clinical relevance of color Doppler twinkling artifacts in fetuses with isolated echogenic intracardiac foci (EIF).

METHODS

This study included 50 fetuses with EIF, at 18-38 weeks of gestation. Echocardiographic examination, which was performed using a 1.0-5.0-MHz phased array probe, included gray-scale, color and spectral Doppler imaging. Twinkling artifacts were assessed using fetal color Doppler echocardiography on isolated EIF situated in the left and/or right ventricles. The prevalence, appearance and clinical relevance of the color Doppler twinkling artifacts were analyzed.

RESULTS

Eight of 50 fetuses with EIF (16%) showed color Doppler twinkling artifacts, which appeared as a rapidly changing color complex seen persistently behind the EIF. The spectra obtained in all eight with color Doppler artifacts were composed of straight vertical bands occurring in mid to late systole and early diastole. After birth, none of 50 fetuses with EIF had structural heart diseases or showed clinical signs of cardiac failure.

CONCLUSIONS

Color Doppler twinkling artifacts from isolated EIF occur in some fetuses and may be considered as an additional echocardiographic feature of EIF. Attention should be paid to the identification and interpretation of these artifacts so that they may be accurately distinguished from true color flow generated by atrioventricular valvular regurgitation jets.

Incidence and clinical significance of interatrial shunting in patients with atrial septal aneurysm detected by contrast transesophageal echocardiography

The prevalence of atrial septal aneurysm (ASA) in a general referral population of patients was investigated by use of transthoracic (TTE) and transesophageal echocardiographies (TEE). Contrast TEE was performed to detect interatrial shunting in patients with ASA. In this population, the prevalence of ASA as determined by TTE was 0.47% (24/5,079), and 0.78% (40/5,079) by TEE. Of these 40 patients 16 (40%) were judged to be normal by TTE. Of the forty patients who were positive for ASA, 50% demonstrated interatrial shunting (atrial septal defects, 10; patent foramen ovale, 10). The authors concluded that TEE is of significant value in detecting the presence of ASA and associated cardiac abnormalities. Contrast TEE further enhances the detection of interatrial shunting in patients with ASA.

The first epidemic of dengue hemorrhagic fever in the People's Republic of China

The first epidemic of dengue in China associated with significant severe and fatal hemorrhagic disease which met the World Health Organization case definition occurred on Hainan Island in 1985-1986. The epidemic began in Zhan County in September 1985, spread throughout the coastal areas, and ultimately involved 13 counties and cities of the island in 1986. The mosquito vector was Aedes aegypti. The morbidity associated with dengue infection on Hainan Island was 1,913 per 100,000 residents, with a case fatality rate of 0.25%. Severe disease was more prevalent in the 10-29-year-old age group. Principal clinical features in laboratory-confirmed cases were fever, osteoarthralgia, hemorrhage and/or shock, and thrombocytopenia. Complications such as acute intravascular hemolysis, diffuse intravascular coagulation, hemoconcentration, pleural effusion, altered mentality, and pneumonia were also observed. One hundred twenty-five isolates of dengue 2 virus were recovered from acute-phase serum samples from 278 patients, and 5 strains of this same virus serotype were isolated from 5 pools of adult Ae. aegypti.