老年性肺结核合并糖尿病128例X-线特征及治疗

目的探讨老年性肺结核合并糖尿病X-线特征及治疗。方法回顾分析128例老年性肺结核合并糖尿病的X-线特征及治疗情况。结果老年性肺结核合并糖尿病X-线特征分布广泛,以广泛渗出干酪病变为主,空洞发生率高。结论老年性肺结核合并糖尿病早诊断,较好控制血糖,延长抗痨才能提高治愈率。

Establishing an Initial Electron Beam Model with Monte Carlo Simulation for a Single 6 MV X-ray Medical Linac Based on Particle Dynamics Characteristics

Objective:In this study,we try to establish an initial electron beam model by combining Monte Carlo simulation method with particle dynamic calculation(TRSV)for the single 6 MV X-ray accelerating waveguide of BJ-6 medical linac.Methods and Materials:1.We adapted the treatment head configuration of BJ-6 medical linac made by Beijing Medical Equipment Institute(BMEI)as the radiation system for this study.2.Use particle dynamics calculation code called TRSV to drive out the initial electron beam parameters of the energy spectrum,the spatial intensity distribution,and the beam incidence angle.3.Analyze the 6 MV X-ray beam characteristics of PDDc,OARc in a water phantom by using Monte Carlo simulation(BEAMnrc,DOSXYZnrc)for a preset of the initial electron beam parameters which have been determined by TRSV,do the comparisons of the measured results of PDDm,OARm in a real water phantom,and then use the deviations of calculated and measured results to slightly modify the initial electron beam model back and forth until the deviations meet the error less than 2%.Results:The deviations between the Monte Carlo simulation results of percentage depth doses at PDDc and off-axis ratios OARc and the measured results of PDDm and OARm in a water phantom were within 2%.Conclusion:When doing the Monte Carlo simulation to determine the parameters of an initial electron beam for a particular medical linac like BJ-6,modifying some parameters based on the particle dynamics calculation code would give some more reasonable and more acceptable results.

^(18)F-DG PET/CT in detection of recurrence and metastasis ofcolorectal cancer

AIM: To evaluate the value of 18F-DG PET/CT in detecting recurrence and/or metastasis of colorectal cancer (CRC). METHODS: Combined visual analysis with semiquantitative analysis, the 18F-DG PET/CT whole- body imaging results and the corresponding clinical data of 68 postoperative CRC patients including 48 male and 20 female with average age of 58.1 were analyzed retrospectively. RESULTS: Recurrence and/or metastasis were confirmed in 56 patients in the clinical follow-up after the PET/CT imaging. The sensitivity of PET/CT diagnosis of CRC recurrence and/or metastasis was 94.6%, and the specificity was 83.3%. The positive predictive value (PPV) was 96.4% and the negative predictive value (NPV) was 76.9%. PET/CT imaging detected one or more occult malignant lesions in 8 cases where abdominal/pelvic CT and/or ultrasonography showed negative findings, and also detected more lesions than CT or ultrasonography did in 30.4% (17/56) cases. Recurrence and/or metastasis was detected in 91.7% (22/24) cases with elevated serum CEA levels by 18F-DG PET/CT imaging. CONCLUSION: 18F-DG PET/CT could detect the recurrence and/or metastasis of CRC with high sensitivity and specificity.

Primary retroperitoneal mucinous cystadenoma:Report of a case and review of the literature

Primary retroperitoneal mucinous cystadenomas (RMCs) are very rare and their biological behavior and histogenesis remain speculative. An accurate preoperative diagnosis of these tumors is difficult because no effective diagnostic measures have been established. We describe a 29-year-old woman with abdominal pain and a palpable mass. Computed tomography (CT) of the abdomen revealed a retroperi-toneal cystic mass which was resected successfully at laparotomy. Histopathological examination of the resected mass confirmed the diagnosis of RMC. There was no evidence of disease 2 years after surgery.

Distribution characteristic and geological signiflcance of rare earth elements in Lopingian mudstone of Permian,Panxian county,Guizhou province

In order to discuss the geochemical characteristic of REEs （rare earth elements） and their geological application, we measured the contents of rare earth elements, trace elements and minerals of 29 Lopingian （Late Permian） mudstone samples in Panxian county, carrying out ICP-MS and XRD analysis. The results show that the amount of REEs （185.56-729.46 ×10-6） is high. The ratios of w（LREE）/w（HREE） （6.84- 13.86） and W（La）N/w（Yb）N （1.01-3.02） show clear differentiation of LREEs and HREEs. ZREE has a significantly or critically positive correlation with lithophile elements Th, Nb, Ta, Ti, Ca, Sc, Cs, Zr, Hf, Sr, Be and chaicophile element Zn, a critically negative correlation with siderophile element Fe and a slightly positive correlation with illite, illite smectite mixed layers and siderite. REEs originate mainly from terrigenous minerals, in an inorganic phase, Source rocks of our samples consist of Emeishan basalt and a small part of sedimentary rocks, as suggested by the distribution patterns of REEs and w（∑REE）- w（La）/w（Yb） diagram. Moreover, abnormal surfaces near the sequence boundaries （SB2, SB3, SB4） are related wiLth the boundaries, identified by geochemical characteristics of the REEs, such as ∑REE. w（LREE）/w（HREE）, Eu/Eu＊ and Ceanom.

Characteristics and genesis of clay minerals in the northern margin of the Qaidam Basin

In order to develop appropriate reservoir protection measures in the northern margin of the Qaidam Basin and improve its oil and gas recovery efficiency,characteristics of clay minerals from eleven clay rock samples from the northern margin of the Qaidam Basin were investigated using X-ray diffraction analysis,the Scanning Electron Microscope（SEM）and energy spectrum analysis.Clay mineral composition and distribution characteristics of the main hydrocarbon reservoirs,i.e.,from the Jurassic and Paleogene-Neogene,were explored.We analyzed the main factors which affected these attributes.The results show that the major clay minerals in the northern margin are chlorite,kaolinite,illite,smectite and illite/smectite inter-stratified minerals.Illite is the most widely spread clay mineral in this area. Chlorite is mainly found in the entire Neogene and in shallow horizons of the Paleogene.Smectite is enriched in the shallow Paleogene-Neogene.There are large amounts of kaolinite and illite/smectite inter-stratified minerals in the Jurassic.The major factors affecting the different development of clay minerals in the region are properties of parent rocks,paleoclimate and paleowater media conditions, diagenesis transformation,tectonic and terrain conditions.

Reservoir characteristics of Donghe well No.1 in Tarim Basin

Based on the techniques of X-ray diffraction analysis, identification of the thin sections of core cast, phys- ical analysis and scanning electron microscopy analysis, this paper studied the reservoir characteristics of the Carboniferous strata in Donghe well No.1 of Tarim region. The results show that the reservoir lithology is mainly the fine-grained quartz sandstone with ferrocalcite and pyrite, mud cement-based, the permeability concentrated in 5-40 × 10-3 μm2, a small part of the high permeability up to 150-327 ×10-3 μm2 and porosity ranged from 10% to 20%. The most part of the reservoirs is low perme- ability with a small part of the layer in moderate-high permeability. The types of reservoir space include intergranular pores, intra particle-molding pores, micro-pores and cracks, which mainly are intergranular pores with the pore diameter of 15-200 μm, 95.5μm on average. And the types of the throats are comolex with the main tvne of constricted l：hroats in this area and large contribution to the permeability.

Local porosity distribution of cement paste characterized by X-ray micro-tomography

Porosity is one of the most important parameters for cement-based materials,which influences the mechanical property,transport property,and durability.The spatial and frequency distributions of local porosity of cement pastes are characterized using X-ray micro-tomography data and treating methods.The 3D spatial distributions for three cement paste specimens with different water cement(w/c)ratios show reasonable heterogeneity.The probability analysis also reveals this heterogeneity:the representative volume element(RVE)size based on porosity maps decreases with w/c ratio firstly,then increases with w/c ratio;and the heterogeneity on the characterized probe size or on the RVE size increases with w/c ratio.Average porosities obtained using the CT method are further compared with those by traditional methods.