A synthetically useful catalytic system for aliphatic C-H oxidation with a nonheme cobalt complex and m-CPBA.

We report herein a synthetically useful catalytic system for aliphatic C-H oxidation with a mononuclear nonheme cobalt(II) complex and m-chloroperbenzoic acid (m-CPBA). Preliminary mechanistic studies suggest that a high-valent cobalt-oxygen species (e.g., cobalt(IV)-oxo or cobalt(III)-oxyl) is the oxidant that effects C-H oxidation via a rate-determining hydrogen atom abstraction (HAA) step.

Effects of Harvesting Grabbing Type on Grabbing Force and Leaf Injury of Lettuce.

Hydroponic lettuce is the main cultivated leafy vegetable in plant factories, and its scattered leaves are delicate and easily injured. Harvesting is an important process in the production of hydroponic lettuce. To reduce the injury level of hydroponic lettuce during harvesting, the impacts of the flexible finger-grabbing position applied on the grabbing force and the area of the injured leaves were investigated in this study by utilizing thin-film sensors and a high-speed video camera. According to the overlapping structural characteristics of adjacent leaves on lettuce, flexible finger-grabbing positions were divided into areas of the surface of the leaves and the intersections of the leaves. Three grabbing types-which are referred to in this paper as Grabbing Types A, B, and C-were identified according to the number of flexible fingers grabbing the leaf surface and the intersection area of the leaves. The force curves of all the flexible fingers were measured by thin film sensors, and the injury area of the leaves was detected using an image processing method. The results showed the consistency of the grabbing force curves and the motion characteristic parameters of the four flexible fingers. The maximum grabbing force of each flexible finger appeared at the stage of pulling the lettuce. The grabbing force of the flexible fingers acting on the intersection areas of the leaves was less than that acting on the leaf surface. As the number of flexible fingers acting on the intersection areas of the leaves increased, both the injury area of the leaves and the grabbing force decreased gradually. Grabbing Type C had the smallest injury area of the leaves: 120.3 ± 13.6 mm2 with an 11.4% coefficient of variation.

Transcriptomics Integrated with Metabolomics Unveil Carotenoids Accumulation and Correlated Gene Regulation in White and Yellow-Fleshed Turnip (Brassica rapa ssp. rapa).

Turnip (Brassica rapa ssp. rapa) is considered to be a highly nutritious and health-promoting vegetable crop, whose flesh color can be divided into yellow and white. It is widely accepted that yellow-fleshed turnips have higher nutritional value. However, reports about flesh color formation is lacking. Here, the white-fleshed inbred line, W21, and yellow-fleshed inbred line, W25, were profiled from the swollen root of the turnip at three developmental periods to elucidate the yellow color formation. Transcriptomics integrated with metabolomics analysis showed that the PSY gene was the key gene affecting the carotenoids formation in W25. The coding sequence of BrrPSY-W25 was 1278 bp and that of BrrPSY-W21 was 1275 bp, and BrrPSY was more highly expressed in swollen roots in W25 than in W21. Transient transgenic tobacco leaf over-expressing BrrPSY-W and BrrPSY-Y showed higher transcript levels and carotenoids contents. Results revealed that yellow turnip formation is due to high expression of the PSY gene rather than mutations in the PSY gene, indicating that a post-transcriptional regulatory mechanism may affect carotenoids formation. Results obtained in this study will be helpful for explaining the carotenoids accumulation of turnips.

The sequence structure and phylogenetic analysis by complete mitochondrial genome of kohlrabi (Brassica oleracea var. gongylodes L.).

Kohlrabi (Brassica oleracea var. gongylodes L.) is an important dietary rhizome vegetable in the Brassicaceae family. However, to date, few mitochondrial genomic resources have been reported for kohlrabi. In this study, we obtained the complete mitochondrial DNA sequence of 219,964 bp from an individual green kohlrabi. A total of 61 genes were annotated, including 33 protein-coding genes, 23 transfer RNA genes, three ribosomal RNA genes, and two pseudo genes. In addition, 1,001 open reading frames and five RNA editing sites were annotated. Relative synonymous codon usage analysis revealed significant difference in usage frequency of synonymous codon. Phylogenetic inference showed that kohlrabi is closely related to B. oleracea var. botrytis. This study provides a good foundation for further understanding the relationship and evolutionary origins among Brassicaceae crops.

Assessment of anatomical and dosimetric changes by a deformable registration method during the course of intensity-modulated radiotherapy for nasopharyngeal carcinoma.

The aim of this study was to quantify the anatomic variations and the dosimetric effects accessed by a deformable registration method throughout the entire course of radiotherapy, and to evaluate the necessity of replanning for patients with nasopharyngeal carcinoma (NPC). Plan1(CT1) was based on the original CT, and Plan2(CT2) was generated from the midtreatment CT scan acquired after 25 fractions of IMRT of Plan1. Both sets of CTs, RT structures and RT doses for the two group plans were transferred to a workstation, and then a hybrid IMRT plan, Plan1(CT2), was generated by deforming doses of Plan1 to CT2. Subsequently, the accumulated plan, Plan1 + 2(CT2), was generated to quantify the actual dosimetric effects during the course. The transverse diameter of the neck at the center of the odontoid process was (15.4 ± 1.0) cm and (14.4 ± 1.1) cm in CT1 and CT2, respectively (P < 0.05). Compared with CT1, the mean volumes of the right and left parotid glands were significantly decreased by (24.6 ± 11.9)% and (35.1 ± 20.1)%, respectively. Comparison of Plan1 (CT1) with Plan1 (CT2) indicated that the doses to targets decreased without replanning. With repeated CT and replanning after 25 fractions, the doses to targets would be improved. The doses to normal tissue were increased without replanning. For eight patients out of 12, the doses to the spinal cord and brainstem exceeded the constraints without replanning, while the corresponding values decreased with replanning. During the entire course of IMRT, the volumes of the targets and the parotid glands would be reduced significantly. Midtreatment CT scanning and replanning are recommended to ensure adaptive doses to the targets and critical normal tissues.

Prediction of the outcome of definitive chemoradiation by decrease in F-18 FDG uptake in nonsurgical esophageal squamous cell cancer.

PURPOSE: To analyze the predictive value of fluorine-18 fluorodeoxyglucose (F-18 FDG) uptake using positron emission tomography and computed tomography to assess the outcome of definitive chemoradiation in nonsurgical esophageal squamous cell carcinoma. MATERIALS AND METHODS: A retrospective review of 61 patients with clinical stage T1-4, N0/1, and M0 was performed. Chemoradiation included chemotherapy with fluorouracil plus cisplatin and irradiation with a total dose of 5600 to 6400 centigray (cGy). Positron emission tomography combined with computed tomography scans were acquired before and during the therapy. The correlation between a decrease in FDG uptake and 5-year progression-free survival (PFS) was analyzed by a receiver operating characteristic curve method to determine a cutoff value. A 5-year overall survival (OS), PFS, and cancer-specific survival (CSS) were evaluated by Kaplan-Meier method. RESULTS: The mean of standardized uptake value decreased significantly during chemoradiation (P = 0.001). Using 51% reduction of FDG uptake as a cutoff value provided a sensitivity of 76.9% and a specificity of 79.2% in predicting PFS (P = 0.000). The positive predictive value and negative predictive value were 50% and 95%, respectively. PFS, CSS, and OS were significantly different when grouped by this cutoff value (P < 0.05), and when dichotomized by stage T1-2 and T3-4 (P < 0.05), simultaneously with a decrease of 51% or more in FDG uptake. CONCLUSIONS: This study showed that a 51% decrease in FDG uptake during chemoradiation was a sensitive and accurate cut-point for predicting PFS. Stage T and decrease in FDG uptake were 2 independent predictive factors for 5-year PFS, CSS, and OS.

Clinical applications of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in carcinoma of unknown primary.

BACKGROUND: Carcinoma of unknown primary (CUP) encompasses a heterogeneous group of tumors with varying clinical features. The management of patients of CUP remains a clinical challenge. The purpose of this study was to evaluate the clinical applications of integrated (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) information in patients with CUP, including detecting the occult primary tumor and effecting on disease therapy. METHODS: One hundred and forty-nine patients with histologically-proven metastases of CUP were included. For all patients, the conventional diagnostic work-up was unsuccessful in localizing the primary site. Whole-body PET/CT images were obtained approximately 60 minutes after intravenous injection of 350 - 425 MBq of (18)F-FDG. RESULTS: In 24.8% of patients, FDG PET/CT detected primary tumors that were not apparent after conventional workup. In this group of patients, the overall sensitivity, specificity, and accuracy rates of FDG PET/CT in detecting unknown primary tumors were 86.0%, 87.7%, and 87.2%, respectively. FDG PET/CT imaging also led to the detection of previously unrecognized metastases in 29.5% of patients. Forty-seven (31.5%, 47 of 149) patients underwent a change in therapeutic management. CONCLUSIONS: FDG PET/CT is a valuable tool in patients with CUP, because it assisted in detecting unknown primary tumors and previously unrecognized distant metastases, and optimized the management of these patients.

Dosimetric comparison of RapidArc with fixed gantry intensity-modulated radiotherapy treatment for multiple liver metastases radiotherapy.

We wanted to compare the dosimetric difference and treatment efficiency of RapidArc and fixed gantry intensity-modulated radiotherapy treatment (IMRT) for multiple liver metastases. Computed tomography datasets of 10 patients were studied retrospectively. IMRT plans were generated using 5 fields and RapidArc using either 1 or 2 arcs. The dose distribution of planning target volume (PTV), organs at risk (OARs), and the normal tissue were compared. Monitor units and treatment time were scored to measure expected treatment efficiency. Both RapidArc and IMRT plans resulted in equivalent target coverage. There was no statistically significant difference for the maximum and the minimum dose of PTV. RapidArc plans achieved an improved conformity index compared with IMRT (RA1 = 1.68 ± 0.27, RA2 = 1.61 ± 0.25, IMRT = 1.80 ± 0.37). For OARs, all techniques respected planning objectives. RapidArc plans had a lower dose in V(40) of small bowel than IMRT, but were higher in mean dose of kidneys. Concerning the V(5), V(10), and V(15) of healthy tissue, RapidArc plans were higher than IMRT. However, the V(20), V(25), and V(30) of healthy tissue in RapidArc plans were lower than IMRT. Monitor units per fraction of RapidArc plans were about 40% or 46% of IMRT. Compared with IMRT plans, treatment time of RapidArc plans were reduced by 60% or 70%. All techniques respected planning objectives. RapidArc showed statistical improvements in conformity index and healthy tissue sparing with uncompromised target coverage. This, in combination with fewer monitor units and short delivery time, can lead to clinically significant advances for the treatment of multiple liver metastases.

Hypofractionated stereotactic radiotherapy for brain metastases: a dosimetric and treatment efficiency comparison between volumetric modulated arc therapy and intensity modulated radiotherapy.

A treatment planning comparison study was performed to evaluate the dosimetric characteristic and treatment efficiency of volumetric modulated arc therapy with step-and-shoot intensity modulated radiotherapy (IMRT) for the hypofractionated stereotactic radiotherapy (HFSRT) in patients with multiple brain metastases. CT datasets of 10 patients with two to four brain metastases were selected for the comparison. Three plans were generated for each case: seven-field step-and-shoot IMRT, single (RA1) and double (RA2) arcs with RapidArc technique (RA, Varian Medical System). The prescribed dose was 50 Gy in 10 fractions and plans were all normalized to the mean dose to the PTV. For PTV, plans aim to achieve at least 98% of PTV was covered with the 95% of prescription dose, at least 95% of PTV was encompassed by the prescription dose, and an over-dosage of 110% of the prescription dose was allowed to 5% volume of the PTV. The plans generated using three techniques were clinically acceptable. The target conformity and homogeneity were improved slightly with RA2 compared to IMRT and RA1. The Paddick CI was 0.868 (IMRT), 0.863 (RA1) and 0.895 (RA2), and HI was 7.7 (IMRT), 7.5 (RA1) and 6.5 (RA2), respectively. Compared with IMRT, the maximum dose in RA2 plans to the brainstem, left and right optic nerves, left and right lens was reduced by 1.6 Gy, 6 Gy, 3 Gy, 1.5 Gy, 1.3 Gy, respectively. The percentage of healthy tissue volume receiving 5 Gy was larger with RA1 (56.7%) and RA2 (57.1%) than with IMRT (52.9%), while the percentages of volume receiving 15 Gy and 20 Gy were smaller with RA1 (27.1%, 18.7%) and RA2 (25%, 16.3%) than with IMRT (28.8%, 19.1%). No significant difference was observed between RA1 and RA2. The mean number of MU per fraction of 5 Gy was 1944 +/- 374 (IMRT), 1199 +/- 173 (RA1) and 1387 +/- 186 (RA2), respectively. Compared with IMRT, the MUs were reduced by 36.8% and 27.2% with RA1 and RA2. The pure beam-on time needed per fraction was 6.5 +/- 1.2 min (IMRT), 1.25 min (RA1) and 2.5 min (RA2), respectively. The beam-on time for RA1 and RA2 was approximately 80% and 40% less compared to IMRT. In conclusion, RA, single arc or double arcs, is a feasible technique with highly conformal dose distribution for the HFSRT in patients with oligo brain metastases. Compared with IMRT, RA1 provides similar plan quality, while RA2 achieves slight improvements in PTV coverage and sparing of organs at risk. The treatment efficiency, using less monitor units and shorter treatment delivery time, is the most obvious advantage.

Measuring tumor cell proliferation with 18F-FLT PET during radiotherapy of esophageal squamous cell carcinoma: a pilot clinical study.

UNLABELLED: The primary aim of this study was to use serial (18)F-3'-deoxy-3'-fluorothymidine (FLT) PET/CT to measure tumor cell proliferation during radiotherapy of squamous cell carcinoma (SCC) of the esophagus. METHODS: Twenty-one patients with inoperable locally advanced SCC of the esophagus underwent serial (18)F-FLT PET/CT during radiotherapy. Each patient received a pretreatment scan, followed by 1-3 scans after delivery of 2, 6, 10, 20, 30, 40, 50, or 60 Gy to the tumor. RESULTS: Among the 19 patients who completed radiotherapy without interruption, parameters reflecting (18)F-FLT uptake in the tumor (i.e., maximum tumor standardized uptake value [SUVmax] and proliferation target volume) decreased steadily. All patients demonstrated an almost complete absence of proliferating esophageal tumor after 30 Gy and a complete absence after 40 Gy. In the 2 patients whose radiotherapy course was interrupted, (18)F-FLT uptake in the tumor was greater after the interruption than before the interruption. Marked early reduction of (18)F-FLT uptake in irradiated bone marrow was observed in all patients, even after only 2 Gy. All showed a complete absence of proliferating marrow in irradiated regions after 10 Gy. Both patients who underwent scans after completing the entire radiotherapy course showed no tumor uptake on (18)F-FLT PET/CT but high uptake on (18)F-FDG PET/CT. Pathologic examination of these regions revealed inflammatory infiltrates but no residual tumor. CONCLUSION: (18)F-FLT uptake can be used to monitor the biologic response of esophageal SCC and normal tissue to radiotherapy. Increased uptake of (18)F-FLT after treatment interruptions may reflect accelerated repopulation. (18)F-FLT PET/CT may have an advantage over (18)F-FDG PET/CT in differentiating inflammation from tumor.