[Spatial Differentiation and Influencing Factor Analysis of Soil Heavy Metal Content at Town Level Based on Geographic Detector].

Geographic detectors can quickly detect spatial stratified heterogeneity and quantitatively reveal the intensity of driving factors of heavy metal content, which is of great significance for the prevention, control, and remediation of soil heavy metal pollution. In order to reveal the spatial differentiation and influencing factors of soil heavy metal content on the town-scale, 788 topsoil samples were collected from a town in the hinterland of Chengdu Plain. Soil heavy metal (Cd, Hg, As, Cu, Pb, Cr, Zn, and Ni) pollution risk assessments were carried out by using the geo-accumulation index method. Additionally, based on the geographic detector model, 15 factors such as soil properties, topography, soil forming factors, and distance were taken as independent variables, and the contents of each heavy metal element were taken as dependent variables to explore the spatial differentiation and influencing factors of heavy metal content in soils. The results showed that:the average contents of Hg, As, Pb, Cr, Cu, Ni, and Zn in the study area were 1.06-1.93 times the background value of Chengdu, and the content of Cd was lower than the background value; among them, Hg reached the light pollution level, and the other seven heavy metals were at the non-pollution level. The spatial distribution of eight heavy metals was significantly different, the correlation among the elements was significant, and a significant correlation was found between most heavy meals with soil properties; however, the correlation with distance factor and topographic factor was relatively weak. The factor detection showed that TP, TK, pH, TOC, elevation, and distance from the railway had the most significant explanatory power for the heavy metal contents. Interaction detection showed that the interaction between soil properties and other factors was the dominant factor for the spatial variation in heavy metals, and elevation, distance from residential area, distance from railways, and distance from industrial areas were also important factors. Risk detection showed that Hg had the most significant difference in the subregion of elevation and distance from railway, whereas the other seven heavy metals had the most significant difference in the sub-regions of influencing factors of soil properties. The spatial distribution of heavy metals varied significantly in soil at the town-scale, which was closely related to soil properties, topography, and human activities in the study area.

[Geochemical Characteristics and Source Apportionment of Soil Elements in an Urban-rural Integration Area: A Case Study in the Qinglong Area of Tianfu New District].

The Qinglong Area of Tianfu New District in China is the connection area of Chengdu city, Sichuan Province, which dominantly supports the primary agricultural products for the metropolis. The soil quality, therefore, has been deteriorating in recent decades due to the intensive planting and industrial pollution. Thus, the evaluation of soil quality and the identification of the pollution sources are significant for sustainable soil planting and regulation. To this end, 395 soil samples were collected, and the parameters of pH, soil organic matter (SOM), total potassium (TK), available potassium (AK), total nitrogen (TN), alkali-hydrolyzable nitrogen (AN), total phosphorus (TP), available phosphorus (AP), Se, B, V, Zn, Mn, Mo, Ni, Co, As, Cd, Cr, Cu, Hg, and Pb were analyzed. The results revealed that TN, Se, Hg, and TP were obviously higher than the background value of the Chengdu Economic Zone, and the Cr, Mn, pH, and TK were depleted. The combination of correlation statistics, geostatistics, and positive matrix factorization (PMF) source analysis revealed that heavy metal enrichments were mainly affected by four sources, namely natural sources (32%)>industrial sources (30%)>agricultural sources (25%)>traffic sources (14%). Likewise, the source apportionments were verified regarding topography, industrial boundary, farmer density, and traffic flow. It was estimated that Mo, Co, Ni, and V were affected by slope; the enrichment of Hg and As was the result of agricultural activities; Cd, Mn, Cr, and Zn were affected by industrial waste diffusion; and Pb, Zn, Cu, Cd, and Hg were related to transportation. To a certain extent, agricultural fertilization and pesticide application have partially controlled soil fertility and pollution (Hg and As).

Diagnostic value of amygdala volume on structural magnetic resonance imaging in Alzheimer's disease.

BACKGROUND: The main clinical manifestation of Alzheimer's disease (AD) is memory loss, which can be accompanied by neuropsychiatric symptoms at different stages of the disease. Amygdala is closely related to emotion and memory. AIM: To evaluate the diagnostic value of amygdala on structural magnetic resonance imaging (sMRI) for AD. METHODS: In this study, 22 patients with AD and 26 controls were enrolled. Their amygdala volumes were measured by sMRI and analyzed using an automatic analysis software. RESULTS: The bilateral amygdala volumes of AD patients were significantly lower than those of the controls and were positively correlated with the hippocampal volumes. Receiver operating characteristic curve analyses showed that the sensitivity of the left and right amygdala volumes in diagnosing AD was 80.8% and 88.5%, respectively. Subgroup analyses showed that amygdala atrophy was more serious in AD patients with neuropsychiatric symptoms, which mainly included irritability (22.73%), sleep difficulties (22.73%), apathy (18.18%), and hallucination (13.64%). CONCLUSION: Amygdala volumes measured by sMRI can be used to diagnose AD, and amygdala atrophy is more serious in patients with neuropsychiatric symptoms.

Organocatalytic tandem three-component reaction of aldehyde, alkyl vinyl ketone, and amide: one-pot syntheses of highly functional alkenes.

An EtPPh(2)- or PPh(3)-catalyzed tandem three-component reaction of aldehyde, alkyl vinyl ketone, and amide is developed. Its further application in one-pot syntheses of highly functional alkenes starting from aldehydes, alkyl vinyl ketones, and amides is realized. A wide variety of highly functional α,ß-unsaturated ketones can be furnished in 68-99% yields with high stereoselectivity (E/Z up to 98 : 2) within overall 3-29.5 h.

[Case control study of different fixing methods for intertrochanteric fractures].

OBJECTIVE: To compare the clinical effects of different fixing methods for intertrochanteric fractures and make theoretical analysis. METHODS: From June 2003 to June 2007, 321 patients with intertrochanteric fractures, male 132 and female 189, ranging in age from 20 to 93 years with an average of 56.8 years, were treated with different fixation including Richard nail (142 cases), proximal femora nail (PFN, 94 cases) and external fixator (85 cases). The clinical data of all the patients were retrospectively analyzed, including the incidence of complications, joint function of hip (according Kudema modified Merli D'Aubigne criteria). RESULTS: All patients were followed up from 10 months to 4 years with an average of 14 months. About the incidence of complications, there was significant difference between the external fixator group and the others two groups (P < 0.05); there was no significant difference between the Richard nail group and the PFN group (P > 0.05). There was significant difference in joint function of hip among three methods. PEN group was best than others two groups. CONCLUSION: There is the best clinical effects and lowest incidence of complications with PFN method, which is the better choice in treating intertrochanteric fractures.

[Changes of myocardial dynamics in early stage of burn and effect of rapid fluid replacement in delayed resuscitation].

OBJECTIVE: To investigate the changes in myocardial dynamics in early phases of burn shock of dogs and the effects of rapid fluid infusion in delayed resuscitation. METHODS: Twelve mongrel dogs were randomly divided into control (n=6) and burn (n=6) groups. The dogs in burn group were subjected to 35% total body surface area (TBSA) III degree burn and were resuscitated with lactate Ringer's solution 6 hours postburn. The volumes and rates of fluid infusion were controlled basically on the urinary output of 1.0 mlxkg(-1)xh(-1) and cardiac output (CO) of 70%-80% of pre-burn values. The mean arterial pressure (MAP), left ventricular systolic pressure (LVSP), maximum rate of intraventricular pressure rise/down (+/-dp/dt max) and cardiac index (CI) were determined at 0.5, 1,2, 6, 7, 8, 10 and 24 hours postburn. RESULTS: The MAP, LVSP, +/-dp/dt max and CI were significantly lowered from their baseline and those of control group at 0.5 hour postburn, and they kept declining until 6 hours postburn. They showed a tendency of elevation and reached or approached the levels of that in control group within 2 hours of resuscitation, and the differences were not significant between the two groups 4 hours after burn (all P>0.05). The amount of infusion fluid within the first 4 hours of resuscitation was (3.63+/-0.99) ml/kg per 1% TBSA. CONCLUSION: The myocardial dynamics is depressed in the early stage of burn, the effective way to improve it is to infuse a large amount of fluid rapidly when resuscitation is delayed.