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Objective：To observe the relationship between GFR and unit volume in single kidney in infants with congenital hydronephrosis measured by 99mTc-DMSA static renal imaging and renal ultrasonography. Methods：According to the classification of hydronephrosis, 38 infants with congenital hydronephrosis within 12 months were divided into six groups: normal left and right kidney groups, mild hydronephrosis left and right kidney groups, and severe hydronephrosis left and right kidney groups. Within one week, all patients received ultrasonic examination, diuretic dynamic renal imaging and static renal imaging respectively, and lateral imagings of both kidneys was performed after static renal imaging. The length,width and thickness of kidneys measured by ultrasound and static renal imaging were substituted into the improvement formula of pediatric renal volume:length×width×thickness×0.674, respectively, to obtain the renal volumes in groups,and the renal function in per unit volume (GFR/unit volume, ml/cm3) was calculated. Paired t test was used for data, and pResults：The length,width and volume of left and right kidneys in normal groups and mild hydronephrosis groups measured by static renal imaging were slightly larger than those from ultrasound, while the renal function in per unit volume were smaller than those measured by ultrasound. On the contrary, the length,width and volume of left and right kidneys in severe hydronephrosis groups were slightly smaller than those from ultrasound, while the renal function in per unit volume were larger than those measured by ultrasound, and the results among all groups had statistical differences (p3（left kidney）in static renal imaging, but the largest renal function in per unit volume in kidney with normal function was 2.20ml/cm3（right kidney）in ultrasonography,and the renal function in per unit volume was significantly higher in right kidney than in left kidney.There were a highly positive correlation between GFR and renal volume in normal left kidney group and mild hydronephrosis left and right kidney groups (normal left kidney group: r=0.865, mild hydronephrosis left kidney group:r=0.872,mild hydronephrosis right kidney group:r=0.822).There were a moderate positive correlation between GFR and renal volume in normal right kidney group and severe hydronephrosis left and right kidney groups (normal right kidney group: r=0.783, severe hydronephrosis left kidney group:r=0.542,severe hydronephrosis right kidney group:r=0.798). There were a linear relationship between GFR and renal volume measured by ultrasonography in groups,and linear regression equations in groups were obtained. Conclusion：The GFR in per unit volume of kidney with normal function was about 1.62-2.20ml/cm3, which was significantly higher in right kidney than in left kidney,and that in kidneys with hydronephrosis also decreased with the gradual aggravated hydronephrosis.

Papillary thyroid carcinoma commonly metastasizes to regional lymph nodes. However, metastasis to liver alone is extremely rare. Here we present a 36-year-old woman who underwent total thyroidectomy and bilateral neck lymph nodes dissection for papillary thyroid carcinoma and received radioiodine (131I) ablation therapy for 2 times 1 month and 5 months after surgery, respectively. The images after the 131I therapy showed a solitary occult metastasis in the liver.

Objective The aim of this study was to evaluate the difference in measured glomerular filtration rate (GFR) of an ectopic pelvic kidney between anterior and posterior image processing using Gates’ method of renal dynamic imaging. Methods A total of 10 patients were studied retrospectively, with a single ectopic kidney in the pelvic cavity and a contralateral kidney at its normal anatomical position confirmed by ultrasound, computed tomography, renal dynamic imaging, etc. All images of ectopic kidneys were processed, and GFRs were measured using anterior and posterior Gates’ method of renal dynamic imaging, respectively. The contralateral normal kidney was only processed on posterior imaging. The total GFRant of one patient, which was equal to the sum of the GFR of a normal kidney on posterior imaging and the GFR of an ectopic kidney on anterior imaging, was compared with the total GFRpost of two kidneys on posterior imaging, with the GFRtwo-sample from the two-sample method, and with the estimated GFR in the Chronic Kidney Disease Epidemiology Collaboration equation. All correlation analyses were carried out between GFRs obtained from three methods, and all patients were followed up. For statistical analysis, nonparametric rank tests were used, Bland-Altman graphs were plotted. Results The mean GFR of the ectopic kidney on anterior imaging was 27.48±12.24 ml/min/1.73 m2. It was higher than the GFR (10.71±4.74 ml/min/1.73 m2) on posterior imaging (t=−2.803, P0.05), but there were statistical differences in the accuracy within 10% of the total GFRant and that of the total GFRpost (P

Scintillators with n-γ discrimination property are widely used in the measurement of neutrons. In sub MeV region, the n-γ discrimination property will be greatly deteriorated so that the neutron and γ-ray events can't be accurately discriminated. As a result, the determination of the proportions of neutron and γ-ray events beyond the discrimination threshold is important if scintillators are applied to measure the low energy neutrons. In the present work, a method based on the time-of-flight technique is proposed to calibrate the proportions of neutron and γ-ray events beyond the discrimination threshold. After the calibration, the numbers of the measured neutron and γ-ray events can be separately determined even if the neutron and γ-ray events can't be perfectly discriminated.

Groundwater pollution risk assessment to delineate areas that are more susceptible to contamination from anthropogenic sources has become an important element for sensible resource management and land use planning. This contribution aims at estimating groundwater pollution risk assessment by applying the DRASTIC model as well as utilizing sensitivity analyses to evaluate the relative importance of the model parameters in San Menxia Basin, Henan Province. The DRASTIC model uses seven environmental parameters (Depth to water, net Recharge, Aquifer media, Soil media, Topography, Impact of vadose zone, and hydraulic Conductivity) to characterize the hydro- geological setting and evaluate groundwater pollution risk assessment.. The part of the labour and agriculture developed area and near by reservoir was dominated by "High" pollution risk classes while the second and third terra part was characterized by "Moderate" pollution risk classes. The elevated the loess part of the study area displayed "Low" pollution risk.The ultimate goal of the study was to define the specifications of an inexpensive easy-to-use computer-based system that would assist state regulatory and planning personal in evaluating groundwater pollution problems.

At present, data packet marking is a good approbatory technology of various schemes for dealing with DDoS attack. Probabilistic packet marking (PPM) is the most representative technology of data packet marking. This paper studies the algorithm of data packet marking in depth, especially for PPM. Research shows there is a serious problem that marking routing information is unfair in different place of the attack path. It will result in reconstructing the attack path needs large numbers of packets. In order to handle this problem, this paper proposes a new algorithm based on marked judging flag (MJF-PM). We set up a marked judging flag in MJF-PM which denotes whether a packet was marked or not. Thus, we can settle the problem of PPM. The result of theoretical analysis and simulated experiment shown, MJF-PM is much better than PPM, and it is feasible.

The atmospheric aerosol number concentration and size distribution were measured at six levels (50, 100, 150, 200, 250 and 300 m) on the Beijing 325 m meteorological tower by means of an optical particle counter. From the measured value of the concentrationNz and according to the expression\(N_Z = N_0 e^{ - {\rm Z}/H_p } \), the value of aerosol scale heightHP was determined by using a least square method. An analysis shows that there are significant variations of aerosol concentration and size distribution in relation to time and altitude. The average size distribution for each level can be described by\(\frac{{dN}}{{dr}} = ar^b e^{ - cr} \), where the parameters vary with the altitude.