A Dosimetric Comparative Study of Carbon-Ion Radiotherapy Versus X-ray Volumetric Modulated Arc Therapy for Stage III Non-Small-Cell Lung Cancer.

BACKGROUND: Compared to photon beam, carbon-ion radiotherapy (CIRT) has both physical and biological advantages. AIM: To examine whether two-dimensional (2D) CIRT is dosimetrically superior to photon beam volume-modulated arc therapy (VMAT) in protecting the normal tissues for stage III non-small-cell lung cancer (NSCLC). SUBJECTS AND METHODS: A retrospective study was conducted. Thirteen patients with stage III NSCLC treated in our center with curative CIRT and a sham photon beam VMAT treatment planning with the same normal tissue dose constraints were included for analysis. Target dose distributions and the homogeneity index (HI) within the planning target volumes were compared. RESULTS: Both CIRT and VMAT plans have good tumor coverage with no significant differences in D98, D95, and D50 of Planning target volume 1 (PTV1) between the two plans. The HIs between the two plans are similar. The HI of PTV2 is superior in the CIRT plan (CIRT vs. VMAT: 0.08 vs. 0.16, P < 0.05). In general, CIRT results in a lower dose of the organ-at-risk (OAR) than the photon plans. The V5, V10, V20, V30, V40, and Dmean of the contralateral lung in the CIRT plan are significantly lower than that of the photon VMAT. For the ipsilateral lung, the V5 of CIRT is significantly lower. The CIRT also had significantly lower spinal cord Dmax, esophageal Dmean and V50, V10 and V30 of bone, and V50 of the trachea and bronchial tree. CONCLUSIONS: Compared with photon VMAT, 2D-CIRT using the passive beam scanning technique significantly reduces the radiation dose to the OARs in curative radiotherapy of stage III NSCLC, suggesting a better protection of the normal tissues.

Acute Toxicity and Hazardous Concentrations of Zinc to Native Freshwater Organisms Under Different pH Values in China.

Zinc bioavailability to aquatic organisms varies greatly under different pH values. In the present study, five native species in China and four common international test species were selected to investigate the influence of changing pH on acute zinc toxicity. The results showed that the higher trophic levels exhibited increasing sensitivity to zinc as pH decreased. However, when the pH value was between 8 and 11, the acute toxicity of zinc was relatively constant. In addition, by using a species-sensitivity distribution (SSD) method, the short-term hazardous concentrations of zinc at different pH values (based on the 5th percentiles of the pH-specific SSDs) were determined to be 17.26 µg/L (pH 4), 48.31 µg/L (pH 5), 80.34 µg/L (pH 6) and 230.6 µg/L (pH 7), respectively. The present study provides useful information for deriving water quality criteria and assessing the risks of metals in the near future.

Structure of mitochondrial DNA control region and genetic diversity of Moschus berezovskii populations in Shaanxi Province.

In China, Moschus berezovskii (forest musk deer), a first-class national protected animal, was earlier widely distributed. However, wild populations of the forest musk deer have declined because of human activity and habitat loss. In order to gather useful information for its conservation and management, we investigated the genetic diversity and population structure of this species by analyzing a 632-bp fragment of mitochondrial DNA (mtDNA) control region in three wild populations in Shaanxi Province, China. The average A+T content (64.1%) of mtDNA was higher than that of G+C (35.9%). A total of 178 variable sites (about 28.03% of the total nucleotides in the sequence) were detected in 71 individuals. The nucleotide diversity (PI) in the 71 individuals was 0.04688, and the average nucleotide differences (K) were 21.238. The 71 individuals belonged to 33 haplotypes according to the determined sequences. The average genetic distance (P) among the haplotypes of the species was 0.169. The phylogenetic tree constructed using the neighbor-joining method revealed that these individuals were clustered into three groups, but the individual distribution in those groups was disordered. These data indicated the variation and rich genetic diversity in the three populations of M. berezovskii. Compared to the wild population in Longxian, those in Liuba and Fengxian had a close kinship. The present results indicated no signs of inbreeding or a decline in genetic diversity in the wild M. berezovskii population.

Discovery and characterization of a first set of polymorphic microsatellite markers in Siganus oramin.

Nine microsatellite DNA markers were developed and characterized for Siganus oramin by the 5'-anchored polymerase chain reaction technique. A total of 42 alleles were identified in 30 individuals, and the number of alleles per locus ranged from 3 to 7, with an average of 4.7. The observed and expected heterozygosity per locus ranged from 0.5333 to 1.0000 and from 0.5254 to 0.8474, respectively, with an average of 0.7422 and 0.6906, respectively. A significant deviation from the Hardy-Weinberg equilibrium was detected at one microsatellite locus after a Bonferroni's correction (P < 0.0056). No significant linkage disequilibrium was found between any of the pairs of the nine loci. The microsatellite loci developed in this study will improve our understanding of the genetic background of S. oramin.

Derivation of freshwater quality criteria for zinc using interspecies correlation estimation models to protect aquatic life in China.

Species sensitivity distributions (SSDs) are usually used in the development of water quality criteria and require a large number of toxicity values to define a hazard level to protect the majority of species. However, some toxicity data for certain chemicals are limited, especially for endangered and threatened species. Thus, it is important to predict the unknown species toxicity data using available toxicity data. To address this need, interspecies correlation estimation (ICE) models were developed by US EPA to predict acute toxicity of chemicals to diverse species based on a more limited data set of surrogate species toxicity data. Use of SSDs generated from ICE models allows for the prediction of protective water quality criteria, such as the HC5 (hazard concentration, 5th percentile). In the present study, we tested this concept using toxicity data collected for zinc. ICE-based-SSDs were generated using three surrogate species (common carp (Cyprinus carpio), rainbow trout (Oncorhynchus mykiss), and Daphnia magna) and compared with the measured-based SSD and corresponding HC5. The results showed that no significant differences were observed between the ICE- and the measured-based SSDs and HC5s. Furthermore, the examination of species placements within the SSDs indicated that the most sensitive species to zinc were invertebrates, especially crustaceans. Given the similarity of SSD and HC5s for zinc, the use of ICE to derive potential water quality criteria for diverse chemicals in China is proposed. Further, a combination of measured and ICE-derived data will prove useful for assessing water quality and chemical risks in the near future.

[HPLC-DAD analysis of thirteen soporific sedative drugs in human blood].

An HPLC-DAD qualitative and quantitative method for the analysis of thirteen soporific sedative drugs in human blood established. These drugs were separated by HPLC with acetonitrile-water (35 : 65) (for barbital drugs), methanol-water (60 : 40) and methanol-10% triethylamine acetic acid solution (pH 7.5) (for benzodiazepam and phenothiazine drugs) as eluting phase systems and were detected with photodiode array detector (DAD). These drugs were identified by their spectral characteristics and retention times and quantitatively determined by their peak areas. In the concentration range 0.5-10 micrograms . ml-1, the concentration of all 13 drugs were in proportion to their peak areas. The correlation coefficients were all up to 0.99. The recovery rates from blood were all above 85% without interference from impurities. This method has been used to detect three poisoning samples from the clinic. Good results have been obtained.

Determination of methaqualone and its metabolites in urine and blood by UV, GC/FID and GC/MS.

A systematic procedure for the determination of methaqualone and its metabolites in blood and urine by UV spectrophotometry, GC and GC/MS was developed. Urine and blood samples were from a suicidal patient who ingested 18 tablets of methaqualone. Both solid phase and liquid-liquid extractions were used in the extraction and clean-up of the samples. The total amount of methaqualone and its metabolites was measured by UV spectrophotometry. The amount of parent methaqualone was quantitated by GC/FID. Methaqualone and its 10 metabolites including two acetyl metabolites were found in urine and blood. This procedure is useful for monitoring drugs in emergency treatment.