Radical Homopolymerization of Linear α-Olefins Enabled by 1,4-Cyano Group Migration.

α-Olefins are valued and abundant building blocks from fossil resources. They are widely used to provide small-molecule or polymeric products. Despite numerous advantages of radical polymerization, it has been well-documented as textbook knowledge that α-olefins and their functionalized derivatives cannot be radically homopolymerized because of the degradative chain transfer side reactions. Herein, we report our studies on the homopolymerization of thiocyanate functionalized α-olefins enabled by 1,4-cyano group migration under radical conditions. By this approach, a library of ABC sequence-controlled polymers with high molecular weights can be prepared. We can also extend this strategy to the homopolymerization of α-substituted styrenic and acylate monomers which are known to be challenging to achieve. Overall, the demonstrated functional group migration radical polymerization could provide new possibilities to synthesize polymers with unprecedented main chain sequences and structures. These polymers are promising candidates for novel polymeric materials.

Tetrahydrocurcumin-Related Vascular Protection: An Overview of the Findings from Animal Disease Models.

Tetrahydrocurcumin (THC), one of the major metabolites of CUR, possesses several CUR-like pharmacological effects; however, its mechanisms of action are largely unknown. This manuscript aims to summarize the literature on the preventive role of THC on vascular dysfunction and the development of hypertension by exploring the effects of THC on hemodynamic status, aortic elasticity, and oxidative stress in vasculature in different animal models. We review the protective effects of THC against hypertension induced by heavy metals (cadmium and iron), as well as its impact on arterial stiffness and vascular remodeling. The effects of THC on angiogenesis in CaSki xenografted mice and the expression of vascular endothelial growth factor (VEGF) are well documented. On the other hand, as an anti-inflammatory and antioxidant compound, THC is involved in enhancing homocysteine-induced mitochondrial remodeling in brain endothelial cells. The experimental evidence regarding the mechanism of mitochondrial dysfunction during cerebral ischemic/reperfusion injury and the therapeutic potential of THC to alleviate mitochondrial cerebral dysmorphic dysfunction patterns is also scrutinized and explored. Overall, the studies on different animal models of disease suggest that THC can be used as a dietary supplement to protect against cardiovascular changes caused by various factors (such as heavy metal overload, oxidative stress, and carcinogenesis). Additionally, the reviewed literature data seem to confirm THC's potential to improve mitochondrial dysfunction in cerebral vasculature during ischemic stroke through epigenetic mechanisms. We suggest that further preclinical studies should be implemented to demonstrate THC's vascular-protective, antiangiogenic, and anti-tumorigenic effects in humans. Applying the methods used in the presently reviewed studies would be useful and will help define the doses and methods of THC administration in various disease settings.

[Feasibility Research of the New Fixation Device Compatible with Head and Neck Coil of MRI for Radiotherapy].

MRI simulation images quality of head and neck coil scanning is better than that of radiotherapy surface coil, but currently the head and neck coil is not compatible with radiotherapy positioning devices. In this paper, a new fixation device is developed based on computer reverse engineering technology, which can be used in combination with head and neck coil. This article focuses on discussing the feasibility of the new device in radiotherapy. The obtained ACR phantom and Cat phantom 504 images were used to analyze MR and CT images quality assurance indicators. The dose attenuation of 6 MV photons was measured using the ionization chamber. The results showed each index met the clinical application requirements of intracranial tumor radiotherapy, thereby it can be used in intracranial tumor radiotherapy.

A Script-Based Automatic Intensity Modulated Radiation Therapy Planning Method With Robust Optimization for Craniospinal Irradiation.

This report describes a script-based automatic planning method with robust optimization for craniospinal irradiation (CSI) to reduce sensitivity to field matching errors and increase planning efficiency. The data of 10 CSI patients with planning target volume (PTV) lengths between 49.8 and 85.0 cm were retrospectively studied. Robust intensity modulated radiation therapy plans with ±5-mm longitudinal position uncertainty were generated by the automatic planning script. A simple dose prediction model and a self-adjusting method were implied in the automatic plans. The plans' robustness against setup errors was evaluated by deliberately shifting the middle beamset ±5 mm in the superior-inferior direction. Manual and nonrobust plans were also created to evaluate the automatic robust plans' quality, efficiency, and robustness. There were no significant differences between the manual and automatic plans in terms of homogeneity index; conformity index; D1%, D2%, and D98% of PTV; and average doses of organs at risk. However, the D99% of the PTV in the automatic plans was slightly inferior to that in the manual plans. Compared with the manual plans, the automatic plans greatly increased efficiency, with a reduction in planning time of approximately 48%. When ±5-mm superior-inferior errors were introduced, the average deviations of the maximum dose D1% and minimum dose D99% to the spinal cord were 4.9% (±1.1%) and -3.4% (±1.3%), respectively. However, the corresponding values of the nonrobust plans were 20.0% (±5.4%) and -21.2 (±6.3%), respectively. The script-based automatic CSI planning method, combining robust optimization and a dose prediction model, efficiently created a good-quality plan that was robust to setup errors.

Endostar down-regulates HIF-1 and VEGF expression and enhances the radioresponse to human lung adenocarcinoma cancer cells.

To study the effect of endostar on the expression of hypoxia-inducible factor 1 (HIF-1) and vascular endothelial growth factor (VEGF) and radiosensitization, the changes of A549 cells treated by endostar, radiotherapy and radiotherapy plus endostar were checked by flow cytometry (FCM), methyl thiazolyl tetrazolium (MTT), hoechst staining, and enzyme linked immunosorbent assay (ELISA). The results showed that endostar could block cell periods of A549 and stopped the cell cycle at G2/M and S periods. Cell growth inhibiting and apoptotic rate in the combination group were higher than those in other groups. Meanwhile, the levels of HIF-1 and VEGF expression in the combination group were lower than those of other groups. It suggested that endostar significantly sensitizes the function of radiation in A549 cells by arresting the cell cycle at stage of G2/M and S, increasing the cell growth inhibiting and the apoptotic rate, down-regulating the expression of HIF-1 and VEGF.

Meta-Analysis of Low Temperature Plasma Radiofrequency Ablation and CO2 Laser Surgery on Early Glottic Laryngeal Carcinoma.

Objective: Meta-analysis is used to analyze the treatment of early glottic laryngeal carcinoma by cryogenic plasma radiofrequency ablation combined with CO2 laser surgery. Methods: Retrieval of PubMed, Embase, Medline, VIP, Wanfang, and CNKI databases using a computer. The retrieval period is from the creation of the database until August 31, 2021. References to the included literature were also searched at the same time. According to the inclusion and exclusion criteria, literatures are screened independently, relevant data were extracted, and meta-analysis was conducted. Results: Recurrence rates are reported in seven literatures. In interstudy heterogeneity test: P = 0.624, I 2 = 0%, fixed effect model analysis shows that there is no significant difference in recurrence rate between low temperature plasma radiofrequency ablation and CO2 laser ablation (OR = 0.80, 95% CI (0.35, 1.29), P = 0.371). Intraoperative blood loss is reported in 5 literatures, and heterogeneity test of each study is as follows: P = 0.03, I 2 = 67%. Low temperature plasma radiofrequency ablation results in more intraoperative blood loss than CO2 laser ablation (SMD = -0.71, 95% CI (0.08, 0.82), P = 0.01). There are five reports on postoperative pain in two treatments: P = 0.04, I 2 = 64%. There is no significant difference in postoperative pain between low temperature plasma radiofrequency ablation and CO2 laser ablation (SMD = -0.21, 95% CI (-0.44, 0.10), P = 0.134). Operative time is reported in nine articles: P < 0.01, I 2 = 95%. The operative time of low temperature plasma radiofrequency ablation is significantly shorter than CO2 laser ablation (SMD = -2.38, 95% CI (-3.91, -1.62), P < 0.01). There are two reports on postoperative mucosal recovery: P = 0.328, I 2 = 2%. Low temperature plasma radiofrequency ablation was significantly better than CO2 laser ablation in postoperative mucosal recovery (OR = 5.49, 95% CI (2.36, 10.18), P < 0.01). Conclusion: Low temperature plasma radiofrequency ablation is superior to CO2 laser surgery in the treatment of early glottic laryngeal carcinoma in terms of operative time and postoperative mucosal recovery. Low-temperature plasma radiofrequency ablation, on the other hand, results in higher intraoperative blood loss, with no discernible difference in recurrence rate or postoperative pain severity between the two treatments.

Evaluating the impact of possible interobserver variability in CBCT-based soft-tissue matching using TCP/NTCP models for prostate cancer radiotherapy.

BACKGROUND: Prostate alignment is subject to interobserver variability in cone-beam CT (CBCT)-based soft-tissue matching. This study aims to analyze the impact of possible interobserver variability in CBCT-based soft-tissue matching for prostate cancer radiotherapy. METHODS: Retrospective data, consisting of 156 CBCT images from twelve prostate cancer patients with elective nodal irradiation were analyzed in this study. To simulate possible interobserver variability, couch shifts of 2 mm relative to the resulting patient position of prostate alignment were assumed as potential patient positions (27 possibilities). For each CBCT, the doses of the potential patient positions were re-calculated using deformable image registration-based synthetic CT. The impact of the simulated interobserver variability was evaluated using tumor control probabilities (TCPs) and normal tissue complication probabilities (NTCPs). RESULTS: No significant differences in TCPs were found between prostate alignment and potential patient positions (0.944 ± 0.003 vs 0.945 ± 0.003, P = 0.117). The average NTCPs of the rectum ranged from 5.16 to 7.29 (%) among the potential patient positions and were highly influenced by the couch shift in the anterior-posterior direction. In contrast, the average NTCPs of the bladder ranged from 0.75 to 1.12 (%) among the potential patient positions and were relatively negligible. CONCLUSIONS: The NTCPs of the rectum, rather than the TCPs of the target, were highly influenced by the interobserver variability in CBCT-based soft-tissue matching. This study provides a theoretical explanation for daily CBCT-based image guidance and the prostate-rectum interface matching procedure. TRIAL REGISTRATION: Not applicable.

[Effects of rh-endostar in combination with radiotherapy on rats with lung cancer].

BACKGROUND AND OBJECTIVE: Radiation sensitivity is closely related to tissue oxygen, and rh-endostatin can induce the high level of oxygen content in tumor by "normalizing" tumor angiogenesis which is associated with radiotherapy sensitivity. The aim of this study is to observe the effect of combination of radiotherapy with rh-endostatin in the rats with lung cancer. METHODS: Immediate lewis cancerous ascetic injection method was used to make rats tumors bearing model, then the rats was divided into four groups randomly: group A was treated with saline; group B was treated with rh-endostatin; group C was treated with irradiation and group D was treated with rh-endostatin and irradiation. After all rats were treated, inhibition rates and the tumor growth curve were calculated. Immunohistochemisty was adopted to check the expressions of vascular endothelial growth factor (VEGF) and microvessel density (MVD). RESULTS: Compared with group A, the growth rates of the tumors in the other group were obviously slower, and the tumor weights were significantly different form group A (P < 0.05). Compared with the other groups, the tumor weights of group D were obviously reduced (P < 0.05). Compared with group A, VEGF and MVD of other three groups were reduced (P < 0.05), and group D were significantly cut down. CONCLUSION: Combination with radiotherapy and rh-endostatin could inhibit the lung cancer significantly in rats. The possible mechanisms are to decrease the expression ofVEGF and inhibit the production of angiogenesis.

Accuracy of real-time respiratory motion tracking and time delay of gating radiotherapy based on optical surface imaging technique.

BACKGROUND: Surface-guided radiation therapy (SGRT) employs a non-invasive real-time optical surface imaging (OSI) technique for patient surface motion monitoring during radiotherapy. The main purpose of this study is to verify the real-time tracking accuracy of SGRT for respiratory motion and provide a fitting method to detect the time delay of gating. METHODS: A respiratory motion phantom was utilized to simulate respiratory motion using 17 cosine breathing pattern curves with various periods and amplitudes. The motion tracking of the phantom was performed by the Catalyst™ system. The tracking accuracy of the system (with period and amplitude variations) was evaluated by analyzing the adjusted coefficient of determination (A_R2) and root mean square error (RMSE). Furthermore, 13 actual respiratory curves, which were categorized into regular and irregular patterns, were selected and then simulated by the phantom. The Fourier transform was applied to the respiratory curves, and tracking accuracy was compared through the quantitative analyses of curve similarity using the Pearson correlation coefficient (PCC). In addition, the time delay of amplitude-based respiratory-gating radiotherapy based on the OSI system with various beam hold times was tested using film dosimetry for the Elekta Versa-HD and Varian Edge linacs. A dose convolution-fitting method was provided to accurately measure the beam-on and beam-off time delays. RESULTS: A_R2 and RMSE for the cosine curves were 0.9990-0.9996 and 0.110-0.241 mm for periods ranging from 1 s to 10 s and 0.9990-0.9994 and 0.059-0.175 mm for amplitudes ranging from 3 mm to 15 mm. The PCC for the actual respiratory curves ranged from 0.9955 to 0.9994, which was not significantly affected by breathing patterns. For gating radiotherapy, the average beam-on and beam-off time delays were 1664 ± 72 and 25 ± 30 ms for Versa-HD and 303 ± 45 and 34 ± 25 ms for Edge, respectively. The time delay was relatively stable as the beam hold time increased. CONCLUSIONS: The OSI technique provides high accuracy for respiratory motion tracking. The proposed dose convolution-fitting method can accurately measure the time delay of respiratory-gating radiotherapy. When the OSI technique is used for respiratory-gating radiotherapy, the time delay for the beam-on is considerably longer than the beam-off.

The extracellular vesicles secreted by lung cancer cells in radiation therapy promote endothelial cell angiogenesis by transferring miR-23a.

Angiogenesis is an important factor contributing to the radioresistance of lung cancer. However, the associated mechanisms underlying radiotherapy-induced pro-angiogenesis are unclear. Here, we demonstrated that Extracellular vesicles (EVs) derived from cultured cells in vitro enhanced HUVEC proliferation and migration, and the enhancement effect became more obvious when HUVECs were treated with EV derived from A549 or H1299, two lung cancer cell lines. Additionally, the pro-angiogenesis effect induced by EV could be strengthened when the lung cancer cells were exposed to X-ray irradiation. Furthermore, we verified that the downregulation of PTEN plays a vital role in this process. By evaluating the changes in the levels of microRNAs(miRNAs) targeting PTEN in EV, we found that miR-23a was significantly upregulated and mediated a decrease in PTEN. A luciferase reporter gene transfer experiment demonstrated that PTEN was the direct target of miR-23a, and the kinetics of PTEN expression were opposite to those of miR-23a. Our results show that the miR-23a/PTEN pathway plays an important role in EV-induced angiogenesis. These findings implicate the miR-23a/PTEN axis as a novel therapeutic target for lung cancer radiotherapy.

Endostar enhances the antitumor effects of radiation by affecting energy metabolism and alleviating the tumor microenvironment in a Lewis lung carcinoma mouse model.

Lung cancer is a leading cause of morbidity and mortality. Previous studies have identified that an improvement in treatment efficacy was achieved using Endostar; however, the role of Endostar in lung cancer remains poorly understood. The present study investigated whether the enhanced antitumor effects of Endostar in combination with radiation involved changes in the metabolism and microenvironment in non-small cell lung cancer. A Lewis lung carcinoma mouse model was used, including the control, Endostar (ES), radiotherapy (RT) and Endostar plus radiotherapy (ES + RT) groups. The tumor inhibition rates and growth were described based on changes in tumor volume. In addition, ultraviolet enzymatic analysis was performed to determine the lactate level and reverse transcription-polymerase chain reaction was used to measure the mRNA expression of lactate dehydrogenase (LDH). A Meph-3 pH meter was used to detect the ranges of tumor interstitial tissue pH, and immunohistochemical analysis was adopted to examine hypoxia within the tumor microenvironment. The tumor inhibition rate of the ES + RT group was significantly higher compared with the other three groups (P<0.05). Following treatment, the lactate levels decreased in all three treatment groups compared with the control, particularly in the ES + RT group (P<0.05). Reduced LDH expression and hypoxic fraction in the tumor microenvironment were also observed in the ES + RT group (P<0.05). Furthermore, changes from acidic to alkaline pH in the tumor microenvironment were detected in the ES + RT group. The present study suggested that Endostar is involved in the regulation of metabolism and tumor microenvironment hypoxia, which may be responsible for the enhanced antitumor effect of Endostar in combination with radiotherapy.

Endostar combined with radiotherapy increases radiation sensitivity by decreasing the expression of TGF-ß1, HIF-1α and bFGF.

The aim of the present study was to determine how Endostar inhibits tumor angiogenesis and increases radiation sensitivity when combined with radiotherapy. In vitro studies were conducted to analyze the expression levels of transforming growth factor-ß1 (TGF-ß1), hypoxia-inducible factor 1 (HIF-1α) and basic fibroblast growth factor (bFGF) in lung adenocarcinoma A549 cells, using the antiangiogenesis drug Endostar combined with radiotherapy. In addition, lung adenocarcinoma A549 cell apoptosis was detected via Hoechst staining. The combination of Endostar with radiotherapy was investigated and the results indicated that this combination significantly inhibited tumor cell proliferation and TGF-ß1, HIF-1α and bFGF expression. Changes in gene expression were found to promote apoptosis, thus, enhancing the inhibition of tumor angiogenesis and ultimately inhibiting tumor cell growth, invasion and metastasis.

[Study on the pollutants removal performance along the advanced treatment in tannery wastewater by O3-BAF].

A pilot-scale hybrid process of ozone and biological aerated filters (BAF) with the capacity of 36 t x d(-1) was applied for advanced treatment of the secondary biologically effluent from a dyeing and tannery park wastewater treatment plant. The pollutants removal performance along the height of different medias BAFs were investigated. The results showed that the average COD and color were 55.4 mg x L(-1) and 12.6 times at the height of 1500 mm in activated carbon BAF, and were 55.6 mg x L(-1) and 9.4 times at the height of 1 800 mm in composite BAF, both of the effluent at each height met the first level B criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002). Along the height of ceramist BAF, the COD and color were seldom removed. In activated carbon BAF and composite BAF, COD and ammonia nitrogen were both greatly decreased at the height of 1 200 mm, then decreased slowly. The biomasses simultaneously reached the maximum at the height of 900 mm in activated carbon, composite and ceramist BAF, with the maxims of 30.69, 28.87 and 15.94 nmol x g(-1), respectively.

[The Effect of Endostatin and Radiotherapy on Human Lung Cancer Cell Line A549 and the Impact of HIF-1 Expression after Therapy.].

BACKGROUND: It has been proven that radiotherapy can induce tumor cells over expressing HIF-1. The aim of this work is to investigate the effect of endostatin and radiotherapy on human lung cancer cell line A549 and the impact of HIF-1 expression after therapy. METHODS: Analysed the cell proliferation periods of the A549 cells after treated by endostatin. The A549 cells were treated with endostatin (ES) and/or radiotherpy (RT), and then the cell growth inhibiting rate was detected by methyl thiazolyl tetrazolium (MTT), the expression of HIF-1 was determined by enzyme linked immunosorbent assay (Elisa). RESULTS: Every treatments can inhibit the growth of A549 cells, but the cells treated with endostatin and radiotherapy were inhibited more obviously. Endostatin had the function of block cell periods on A549, it stoped the A549 cells at G2/M and S periods. Treatment of endostatin and radiotherapy can reduce the expression of HIF-1 induced by radiotherapy. CONCLUSIONS: Endostatin was synergistical with the effect of radiotherapy on inhibiting the growth rate of the A549 cells. This synergism may come from: endostatin can make A549 cells accumulated in G2-M and S transition, thereby inhibiting the proliferation of the A549 cells. HIF-1 is a important factor in resistant of cemotherapy and radiotherapy. Endostatin can inhibite the producing of HIF-1 by cells itself or induced by radiation, so increasing the treatment effect of radiotherapy.