Search

ICE1, a regulator of the cold-inducible transcriptome and freezing tolerance, is currently widely believed to be involved in plant resistance to cold stress. In this study, CfICE1 from Cryptomeria fortunei was transformed into poplar. Physiological indicators of transgenic, empty vector and wild-type poplar after abiotic stress (cold, drought and salt) were determined. Transgenic lines had a higher chlorophyll content, antioxidant enzyme activity and soluble protein content, as well as a lower malondialdehyde and hydrogen peroxide content. The ultrastructure of the plant was observed by transmission electron microscopy, and after stress, the cell structure of the transgenic line was more complete than that of the wild type. CfICE1 was upregulated in transgenic poplar trees after abiotic stress (cold, drought and salt). The CfICE1 transgenic plants improved plant resistance by regulating the CBF gene of poplar under cold and salt stress. In terms of plant responses to abiotic stress, this study showed that overexpression of CfICE1 improved the cold, drought and salt tolerance of poplars. [ABSTRACT FROM AUTHOR]

Low temperatures affect plant growth, development, and geographical distribution. Cryptomeriafortunei (Chinese cedar) is a major industrial tree species used for timber manufacturing in southern China. However, its popularization and application in northern China are limited due to its poor low-temperature resistance (approximately −6 °C), and its overwintering mechanism remains unclear. Here, we performed physiological, metabolomic, and transcriptomic analyses of overwintering C.fortunei needles at three stages: before winter, during winter, and in early spring. Physiological analyses showed that electrolyte leakage, H2O2, malondialdehyde (MDA), soluble sugar, and protein contents increased, while the maximum quantum yield of photosystem II (PSII) (Fv/Fm), effective quantum yield of PSII (YII), and chlorophyll content decreased as overwintering progressed. Metabolomic and transcriptomic analyses revealed that downregulated gibberellin (GA), salicylic acid (SA), cytokinin (CTK), and auxin signal transduction and upregulated abscisic acid (ABA), ethylene, brassinosteroids (BR), and jasmonic acid (JA) signal transduction pathways promoted the winter acclimation of C.fortunei, while the opposite expression pattern promoted the transition from dormancy to growth. In addition, upregulated genes/metabolites involved in phenylpropanoid and flavonoid biosynthesis, starch and sucrose metabolism, cold-related protein and fatty acid desaturases, and downregulated photosynthesis-related pathways promoted winter acclimation, while five (WRKY, AP2/ERF, NAC, MYB, and bHLH) and three (AP2/ERF, MYB, and bHLH) transcription factors were associated with winter acclimation and early spring transition from dormancy to growth, respectively. In summary, we report the first transcriptome of overwintering C.fortunei, providing a foundation for the cultivation of and research on overwintering varieties. [ABSTRACT FROM AUTHOR]

Chinese cedar (Cryptomeria fortunei) is a tree species with important ornamental, medicinal, and economic value. Terpenoids extracted from the essential oil of C. fortunei needles have been considered valuable ingredients in the pharmaceutical and cosmetic industries. However, the possible gene regulation mechanisms that limit terpenoid biosynthesis in this genus are poorly understood. Here, we adopted integrated metabolome analysis, transcriptome, small-RNA (sRNA), and degradome sequencing to analyze the differences in terpenoid regulatory mechanisms in two different overwintering C. fortunei phenotypes (wild-type and an evergreen mutant). A total of 1447/6219 differentially synthesized metabolites (DSMs)/unigenes (DEGs) were detected through metabolome/transcriptome analyses, and these DSMs/DEGs were significantly enriched in flavonoid and diterpenoid biosynthesis pathways. In C. fortunei needles, 587 microRNAs (miRNAs), including 67 differentially expressed miRNAs (DERs), were detected. Among them, 8346 targets of 571 miRNAs were predicted using degradome data, and a 72-miRNA-target regulatory network involved in the metabolism of terpenoids and polyketides was constructed. Forty-one targets were further confirmed to be involved in terpenoid backbone and diterpenoid biosynthesis, and target analyses revealed that two miRNAs (i.e., aly-miR168a-5p and aof-miR396a) may be related to the different phenotypes and to differential regulation of diterpenoid biosynthesis. Overall, these results reveal that C. fortunei plants with the evergreen mutation maintain high terpenoid levels in winter through miRNA-target regulation, which provides a valuable resource for essential oil-related bioengineering research. [ABSTRACT FROM AUTHOR]

Purpose: Stereotactic radiosurgery (SRS) has become an important modality in the treatment of brain metastases. The purpose of this study is to investigate the potential of radiomic features from planning magnetic resonance (MR) images and dose maps to predict local failure after SRS for brain metastases. Materials/Methods: Twenty‐eight patients who received Gamma Knife (GK) radiosurgery for brain metastases were retrospectively reviewed in this IRB‐approved study. 179 irradiated tumors included 42 that locally failed within one‐year follow‐up. Using SRS tumor volumes, radiomic features were calculated on T1‐weighted contrast‐enhanced MR images acquired for treatment planning and planned dose maps. 125 radiomic features regarding tumor shape, dose distribution, MR intensities and textures were extracted for each tumor. Logistic regression with automatic feature selection was built to predict tumor progression from local control after SRS. Feature selection and model evaluation using receiver operating characteristic (ROC) curves were performed in a nested cross validation (CV) scheme. The associations between selected radiomic features and treatment outcomes were statistically assessed by univariate analysis. Results: The logistic model with feature selection achieved ROC AUC of 0.82 ± 0.09 on 5‐fold CV, providing 83% sensitivity and 70% specificity for predicting local failure. A total of 10 radiomic features including 1 shape feature, 6 MR images and 3 dose distribution features were selected. These features were significantly associated with treatment outcomes (p < 0.05). The model was validated on independent holdout data with an AUC of 0.78. Conclusions: Radiomic features from planning MR images and dose maps provided prognostic information in SRS for brain metastases. A model built on the radiomic features shows promise for early prediction of tumor local failure after treatment, potentially aiding in personalized care for brain metastases. [ABSTRACT FROM AUTHOR]

Main conclusion: Comparative analysis of miRNAs and their gene targets between the evergreen and yellowish-brown Cryptomeria fortunei phenotypes in cold winters suggests a possible role of miRNA-regulated pathways in needle color. Cryptomeria fortunei (Chinese cedar) is a conifer tree of considerable economic, ornamental and ecological importance. Despite the evergreen nature of C. fortunei, most needles turn yellowish- or reddish-brown in winter. The roles of microRNAs (miRNAs) in regulating pigment biosynthesis in color-leafed plants have been widely investigated. However, whether or not an miRNA-mediated staged discoloration mechanism exists in evergreen C. fortunei is currently unknown. In this study, we deciphered the microRNAs landscape in overwintering C. fortunei needles using high-throughput sequencing. A total of 517 known and 212 novel miRNA mature/star sequences, including 233 differentially expressed miRNAs, were identified. Based on integrated transcriptome and miRNA analysis, 2702 target unigenes of the miRNAs were predicted and these targets were significantly enriched in pigment-related biosynthesis pathways. A miRNA-target pigment biosynthesis regulatory network was then constructed, and its module miRNA (ath-miR858b, aly-miR858-3p, cme-miR828 and novel33_mature)–MYBs (v-myb avian myeloblastosis viral oncogene homolog) appeared to be a key factor regulating needle discoloration in C. fortunei. These miRNA–MYBs were further confirmed by degradome sequencing. Overall, these findings provide new insight into the posttranscriptional regulatory mechanism of leaf/needle discoloration in gymnosperms and may contribute to the miRNA-mediated genetic improvement of evergreen C. fortunei needles. [ABSTRACT FROM AUTHOR]

Objective: To determine the long-term normal tissue complication probability with stereotactic body radiation therapy (SBRT) treatments for targets that move with respiration and its relation with the type of respiratory motion management (tracking vs. compression or gating). Methods: A PubMed search was performed for identifying literature regarding dose, volume, fractionation, and toxicity (grade 3 or higher) for SBRT treatments for tumors which move with respiration. From the identified papers logistic or probit dose-response models were fitted to the data using the maximum-likelihood technique and confidence intervals were based on the profile-likelihood method in the dose-volume histogram (DVH) Evaluator. Results: Pooled logistic and probit models for grade 3 or higher toxicity for aorta, chest wall, duodenum, and small bowel suggest a significant difference when live motion tracking was used for targeting tumors with move with respiration which was on the average 10 times lower, in the high dose range. Conclusion: Live respiratory motion management appears to have a better toxicity outcome when treating targets which move with respiration with very steep peripheral dose gradients. This analysis is however limited by sparsity of rigorous data due to poor reporting in the literature. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to quantify dosimetric changes throughout the delivery of oropharyngeal cancer treatment and to investigate the application of statistical process control (SPC) for the management of significant deviations during the course of radiotherapy. Methods: Thirteen oropharyngeal cancer patients with daily cone beam computed tomography (CBCT) were retrospectively reviewed. Cone beam computed tomography images of every other fraction were imported to the Velocity software and registered to planning CT using the 6 DOF (degrees of freedom) couch shifts generated during patient setup. Using Velocity "Adaptive Monitoring" module, the setup‐corrected CBCT was matched to planning CT using a deformable registration. Volumes and dose metrics at each fraction were calculated and rated with plan values to evaluate interfractional dosimetric variations using a SPC framework. T‐tests between plan and fraction volumes were performed to find statistically insignificant fractions. Average upper and lower process capacity limits (UCL, LCL) of each dose metric were derived from these fractions using conventional SPC guidelines. Results: Gross tumor volume (GTV) and organ at risk (OAR) volumes in the first 13 fractions had no significant changes from the pretreatment planning CT. The GTV and the parotid glands subsequently decreased by 10% at the completion of treatment. There were 3–4% increases in parotid mean doses, but no significant differences in dose metrics of GTV and other OARs. The changes were organ and patient dependent. Control charts for various dose metrics were generated to assess the metrics at each fraction for individual patient. Conclusions: Daily CBCT could be used to monitor dosimetric variations of targets and OARs resulting from volume changes and tissue deformation in oropharyngeal cancer radiotherapy. Treatment review with the guidance of a SPC tool allows for an objective and consistent clinical decision to apply adaptive radiotherapy. [ABSTRACT FROM AUTHOR]

Key points Central hypercapnic hypoventilation is highly prevalent in children suffering from congenital central hypoventilation syndrome (CCHS)., Mutations of the gene for paired-like homeobox 2b (Phox2b) are aetiologically associated with CCHS and Phox2b is present in central components of respiratory chemoreflex, such as the nucleus tractus solitarius (NTS)., Injection of the neurotoxin substance P-saporin into NTS destroys Phox2b-expressing neurons. Impaired hypercapnic ventilatory response caused by this neurotoxin is attributable to a loss of CO2-sensitive Phox2b-expressing NTS neurons., A subgroup of Phox2b-expressing neurons exhibits intrinsic chemosensitivity. A background K+ channel-like current is partially responsible for such chemosensitivity in Phox2b-expressing neurons., The present study helps us better understand the mechanism of respiratory deficits in CCHS and potentially locates a brainstem site for development of precise clinical intervention., Abstract The nucleus tractus solitarius (NTS) neurons have been considered to function as central respiratory chemoreceptors. However, the common molecular marker defined for these neurons remains unknown. The present study investigated whether paired-like homeobox 2b (Phox2b)-expressing NTS neurons are recruited in hypercapnic ventilatory response (HCVR) and whether these neurons exhibit intrinsic chemosensitivity. HCVR was assessed using whole body plethysmography and neuronal chemosensitivity was examined by patch clamp recordings in brainstem slices or dissociated neurons from Phox2b-EGFP transgenic mice. Injection of the neurotoxin substance P-saporin (SSP-SAP) into NTS destroyed Phox2b-expressing neurons. Minute ventilation and tidal volume were both reduced by 13% during exposure to 8% CO2 in inspired air when ∼13% of the Phox2b-expressing neurons were eliminated. However, a loss of ∼18% of these neurons was associated with considerable decreases in minute ventilation by ≥18% and in tidal volume by≥22% when challenged by ≥4% CO2. In both cases, breathing frequency was unaffected. Most CO2-activated neurons were immunoreactive to Phox2b. In brainstem slices, ∼43% of Phox2b-expressing neurons from Phox2b-EGFP mice displayed a sustained or transient increase in firing rate during physiological acidification (pH 7.0 or 8% CO2). Such a response was also present in dissociated neurons in favour of an intrinsic property. In voltage clamp recordings, a background K+ channel-like current was found in a subgroup of Phox2b-expressing neurons. Thus, the respiratory deficits caused by injection of SSP-SAP into the NTS are attributable to proportional lesions of CO2/H+-sensitive Phox2b-expressing neurons. [ABSTRACT FROM AUTHOR]

Purpose The purpose of this study was to evaluate a plastic scintillation detector for the measurement of small field dosimetry and to verify the accuracy of measured dose in comparison with Monte Carlo calculation in a heterogeneous medium. Methods The study is performed with CyberKnife planning and delivery system. The setup consists of a custom made solid lung phantom with the insert of an Exradin W1 scintillation detector or an Exradin A16 ion chamber. The measurement was done for a series of cone sizes from 5 mm to 60 mm, and the dose was calculated by Monte Carlo algorithm in MultiPlan workstation. The difference between measurement and calculation was reported. Results Our preliminary results demonstrated the applicability of plastic scintillation detectors in the measurement of small field dosimetry in a heterogeneous medium. The difference between the calculated and measured output factors was less than 3% for all cone sizes from 60 mm down to 5 mm. Without any corrections, the measured dose from the scintillation detector calibrated to the ion chamber reading was also within 3% of the Monte Carlo calculation in the lung phantom for cone sizes 20 mm or larger. Conclusions Small field dosimetry is particularly relevant to stereotactic radiation treatment. The accuracy of dose calculation for small static beams is critical to dose planning so would potentially affect the treatment outcomes in a heterogeneous medium. Our results have shown good agreement with plastic scintillation detector in both homogeneous and heterogeneous medium. [ABSTRACT FROM AUTHOR]

We present an example when profile measurement and modeling of an Elekta Agility multileaf collimator (MLC) had a large effect specifically on arc therapy plan quality assurance (QA) results using ArcCheck. ArcCheck absolute dose measurements of these plans were systematically lower than planned by 3-10%. Failing QA results were seen even with unmodulated static and conformal arcs. Furthermore, the effect was found to be dependent on collimator angle, with worse results associated with near-zero collimator angles. In contrast, step-and-shoot QA results were not affected. Changing the beam model to match steeper profile measurements obtained using a different measurement device resolved the problem. This case study demonstrates that conventional gamma index analysis can be sensitive to small profile modeling changes. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the dosimetric feasibility of accelerated partial breast irradiation (APBI) using CyberKnife. Methods: Fourteen previously treated patients with early-stage breast cancer were selected for a retrospective study. Six of these patients had been treated to 38.5 Gy in 10 fractions in a phase III accelerated partial breast trial and the rest of the patients were treated to 50.4 Gy in 28 fractions. In this planning study, the guidelines in the protocol for the phase III partial breast trial were followed for organ delineation and CyberKnife planning. The achievable dosimetric parameters from all CyberKnife plans were compared to Intensity-modulated radiation therapy (IMRT) and 3D-CRT methods. The reproducibility of the dose delivery with and without respiratory motion was assessed through delivering a patient plan to a breast phantom. Different dose calculation algorithms were also compared between ray tracing and Monte Carlo. Results: For all the patients in the study, the dosimetric parameters met the guidelines from the NSABP B39/RTOG 0413 protocol strictly. The mean PTV volume covered by 100% of the prescription dose was 95.7 ± 0.7% (94.7%-97.1%). The mean maximal dose was 104 ± 2% of the prescription dose. The mean V50% and mean V100% to the ipsilateral normal breast were 23.1 ± 11.6% and 9.0 ± 5.8%, respectively. The conformity index of all plans was 1.14 ± 0.04. The maximum dose to the contralateral breast varied from 1.3 cGy to 111 cGy. The mean V5% and mean V30% to the contralateral and ipsilateral lungs were 1.0 ± 1.6% and 1.3 ± 1.2%, respectively. In our study, the mean V5% to the heart was 0.2 ± 0.5% for right-sided tumors and 9.4 ± 10.1% for left-sided tumors. Compared with IMRT and 3D-CRT planning, the PTV coverage from CyberKnife planning was the highest, and the ratio of V20% to V100% of the breast from CyberKnife planning was the smallest. The heart and lung doses were similar in all the techniques except that the V5% for the lung and heart in CyberKnife planning was slightly higher. Conclusions: The dosimetric feasibility of APBI using CyberKnife was investigated in this retrospective study. All the dosimetric parameters strictly met the guidelines from the NSABP B39/RTOG 0413 protocol. With advanced real-time tracking capability, CyberKnife should provide better target coverage and spare nearby critical organs for APBI treatment. [ABSTRACT FROM AUTHOR]

Fault diagnosis of wind turbines is of great importance to reduce operating and maintenance costs of wind farms. At present, most wind turbine fault diagnosis methods are focused on single faults, and the methods for combined faults usually depend on inefficient manual analysis. Filling the gap, this paper proposes a low-pass filtering empirical wavelet transform (LPFEWT) machine learning based fault diagnosis method for combined fault of wind turbines, which can identify the fault type of wind turbines simply and efficiently without human experience and with low computation costs. In this method, low-pass filtering empirical wavelet transform is proposed to extract fault features from vibration signals, LPFEWT energies are selected to be the inputs of the fault diagnosis model, a grey wolf optimizer hyperparameter tuned support vector machine (SVM) is employed for fault diagnosis. The method is verified on a wind turbine test rig that can simulate shaft misalignment and broken gear tooth faulty conditions. Compared with other models, the proposed model has superiority for this classification problem. [ABSTRACT FROM AUTHOR]

MicroRNA (miRNA) expression analysis is very important for investigating its functions. To date, no research on reference genes (RGs) for miRNAs in gymnosperms, including Cryptomeria fortunei, has been reported. Here, ten miRNAs (i.e., pab-miR159a, cln-miR162, cas-miR166d, pab-miR395b, ppt-miR894, cln-miR6725, novel1, novel6, novel14 and novel16) and three common RGs (U6, 5S and 18S) were selected as candidate RGs. qRT-PCR was used to analyse their expressions in C. fortunei under various experimental conditions, including multiple stresses (cold, heat, drought, salt, abscisic acid and gibberellin) and in various tissues (roots, stems, tender needles, cones and seeds). Four algorithms (delta Ct, geNorm, NormFinder and BestKeeper) were employed to assess the stability of candidate RG expression; the geometric mean and RefFinder program were used to comprehensively evaluate RG stability. According to the results, novel16, cln-miR6725, novel1 and U6 were the most stable RGs for studying C. fortunei miRNA expression. In addition, the expression of three target miRNAs (aly-miR164c-5p, aly-miR168a-5p and smo-miR396) was examined to verify that the selected RGs are suitable for miRNA expression normalisation. This study may aid further investigations of miRNA expression/function in the response of C. fortunei to abiotic stress and provides an important basis for the standardisation of miRNA expression in other gymnosperm species. [ABSTRACT FROM AUTHOR]

Cryptomeria fortunei has become one of the main timber afforestation species in subtropical high-altitude areas of China due to its fast growth, good material quality, and strong adaptability, showing broad application prospects. Quantitative real-time PCR (qRT-PCR) is the most accurate and widely used gene expression evaluation technique, and selecting appropriate reference genes (RGs) is essential for normalizing qRT-PCR results. However, suitable RGs for gene expression normalization in C. fortunei have not been reported. Here, we tested the expression stability for 12 RGs in C. fortunei under various experimental conditions (simulated abiotic stresses (cold, heat, drought, and salinity) and hormone treatments (methyl jasmonate, abscisic acid, salicylic acid, and gibberellin) and in different tissues (stems, tender needles, needles, cones, and seeds) using four algorithms (delta Ct, geNorm, NormFinder, and BestKeeper). Then, geometric mean rankings from these algorithms and the RefFinder program were used to comprehensively evaluate RG stability. The results indicated CYP, actin, UBC, and 18S as good choices for studying C. fortunei gene expression. qRT-PCR analysis of the expression patterns of three target genes (CAT and MAPK1/6) further verified that the selected RGs were suitable for gene expression normalization. This study provides an important basis for C. fortunei gene expression standardization and quantification. [ABSTRACT FROM AUTHOR]

Most conventional wind turbine fault diagnosis techniques only use a single type of signal as fault feature and their performance could be limited to such signal characteristics. In this paper, multiple types of signals including vibration, temperature, and stator current are used simultaneously for wind turbine misalignment diagnosis. The model is constructed by integrated methods based on Dempster–Shafer (D–S) evidence theory. First, the time domain, frequency domain, and time–frequency domain features of the collected vibration, temperature, and stator current signal are respectively taken as the inputs of the least square support vector machine (LSSVM). Then, the LSSVM outputs the posterior probabilities of the normal, parallel misalignment, angular misalignment, and integrated misalignment of the transmission systems. The posterior probabilities are used as the basic probabilities of the evidence fusion, and the fault diagnosis is completed according to the D–S synthesis and decision rules. Considering the correlation between the inputs, the vibration and current feature vectors' dimensionalities are reduced by t-distributed stochastic neighbor embedding (t-SNE), and the improved artificial bee colony algorithm is used to optimize the parameters of the LSSVM. The results of the simulation and experimental platform demonstrate the accuracy of the proposed model and its superiority compared with other models. [ABSTRACT FROM AUTHOR]

Radiobiological models have been used to calculate the outcomes of treatment plans based on dose–volume relationship. This study examines several radiobiological models for the calculation of tumor control probability (TCP) of intensity modulated radiotherapy plans for the treatment of lung, prostate, and head and neck (H&N) cancers. Dose volume histogram (DVH) data from the intensity modulated radiotherapy plans of 36 lung, 26 prostate, and 87 H&N cases were evaluated. The Poisson, Niemierko, and Marsden models were used to calculate the TCP of each disease group treatment plan. The calculated results were analyzed for correlation and discrepancy among the three models, as well as different treatment sites under study. The median value of calculated TCP in lung plans was 61.9% (34.1–76.5%), 59.5% (33.5–73.9%) and 32.5% (0.0–93.9%) with the Poisson, Niemierko, and Marsden models, respectively. The median value of calculated TCP in prostate plans was 85.1% (56.4–90.9%), 81.2% (56.1–88.7%) and 62.5% (28.2–75.9%) with the Poisson, Niemierko, and Marsden models, respectively. The median value of calculated TCP in H&N plans was 94.0% (44.0–97.8%) and 94.3% (0.0–97.8%) with the Poisson and Niemierko models, respectively. There were significant differences between the calculated TCPs with the Marsden model in comparison with either the Poisson or Niemierko model (p < 0.001) for both lung and prostate plans. The TCPs calculated by the Poisson and Niemierko models were significantly correlated for all three tumor sites. There are variations with different radiobiological models. Understanding of the correlation and limitation of a TCP model with dosimetric parameters can help develop the meaningful objective functions for plan optimization, which would lead to the implementation of outcome-based planning. More clinical data are needed to refine and consolidate the model for accuracy and robustness. This study has tested three radiobiological models with varied disease sites. It is significant to compare different models with the same data set for better understanding of their clinical applicability. [ABSTRACT FROM AUTHOR]

Introduction. Brachytherapy plays a key role in the treatment of many gynecologic cancers. However, some patients are unable to tolerate brachytherapy for medical or other reasons. For these patients, stereotactic body radiotherapy (SBRT) offers an alternative form of treatment. Methods. Retrospective review of patients prospectively collected on SBRT database is conducted. A total of 11 gynecologic patients who could not have brachytherapy received SBRT for treatment of their malignancies. Five patients have been candidates for interstitial brachytherapy, and six have required tandem and ovoid brachytherapy. Median SBRT dose was 25 Gy in five fractions. Results. At last followup, eight patients were alive, and three patients had died of progressive disease. One patient had a local recurrence. Median followup for surviving patients was 420 days (median followup for all patients was 120 days). Two patients had acute toxicity (G2 dysuria and G2 GI), and one patient had late toxicity (G3 GI, rectal bleeding requiring cauterization). Conclusions. Our data show acceptable toxicity and outcome for gynecologic patients treated with SBRT who were unable to receive a brachytherapy boost. This treatment modality should be further evaluated in a phase II study. [ABSTRACT FROM AUTHOR]