Comparison of volumetric modulated arc therapy and helical tomotherapy for prostate cancer using Pareto fronts.

BACKGROUND: Studies comparing different radiotherapy treatment techniques-such as volumetric modulated arc therapy (VMAT) and helical tomotherapy (HT)-typically compare one treatment plan per technique. Often, some dose metrics favor one plan and others favor the other, so the final plan decision involves subjective preferences. Pareto front comparisons provide a more objective framework for comparing different treatment techniques. A Pareto front is the set of all treatment plans where improvement in one criterion is possible only by worsening another criterion. However, different Pareto fronts can be obtained depending on the chosen machine settings. PURPOSE: To compare VMAT and HT using Pareto fronts and blind expert evaluation, to explain the observed differences, and to illustrate limitations of using Pareto fronts. METHODS: We generated Pareto fronts for twenty-four prostate cancer patients treated at our clinic for VMAT and HT techniques using an in-house script that controlled a commercial treatment planning system. We varied the PTV under-coverage (100% - V95%) and the rectum mean dose, and fixed the mean doses to the bladder and femoral heads. In order to ensure a fair comparison, those fixed mean doses were the same for the two treatment techniques and the sets of objective functions were chosen so that the conformity indexes of the two treatment techniques were also the same. We used the same machine settings as are used in our clinic. Then, we compared the VMAT and HT Pareto fronts using a specific metric (clinical distance measure) and validated the comparison using a blinded expert evaluation of treatment plans on these fronts for all patients in the cohort. Furthermore, we investigated the observed differences between VMAT and HT and pointed out limitations of using Pareto fronts. RESULTS: Both clinical distance and blind treatment plan comparison showed that VMAT Pareto fronts were better than HT fronts. VMAT fronts for 10 and 6 MV beam energy were almost identical. HT fronts improved with different machine settings, but were still inferior to VMAT fronts. CONCLUSIONS: That VMAT Pareto fronts are better than HT fronts may be explained by the fact that the linear accelerator can rapidly vary the dose rate. This is an advantage in simple geometries that might vanish in more complex geometries. Furthermore, one should be cautious when speaking about Pareto optimal plans as the best possible plans, as their calculation depends on many parameters.

In Vivo Metabolic Imaging of [1-13 C]Pyruvate-d3 Hyperpolarized By Reversible Exchange With Parahydrogen.

Metabolic magnetic resonance imaging (MRI) using hyperpolarized (HP) pyruvate is becoming a non-invasive technique for diagnosing, staging, and monitoring response to treatment in cancer and other diseases. The clinically established method for producing HP pyruvate, dissolution dynamic nuclear polarization, however, is rather complex and slow. Signal Amplification By Reversible Exchange (SABRE) is an ultra-fast and low-cost method based on fast chemical exchange. Here, for the first time, we demonstrate not only in vivo utility, but also metabolic MRI with SABRE. We present a novel routine to produce aqueous HP [1-13 C]pyruvate-d3 for injection in 6 minutes. The injected solution was sterile, non-toxic, pH neutral and contained ≈30 mM [1-13 C]pyruvate-d3 polarized to ≈11 % (residual 250 mM methanol and 20 µM catalyst). It was obtained by rapid solvent evaporation and metal filtering, which we detail in this manuscript. This achievement makes HP pyruvate MRI available to a wide biomedical community for fast metabolic imaging of living organisms.

Palladium Nanoparticle-Loaded Mesostructural Natural Woods for Efficient Water Treatment.

Natural wood with oriented microchannels and unique multi-level structures is an ideal candidate for making water treatment membranes. Here, palladium nanoparticles are loaded into different kinds of natural woods and the degradation property of the wood membranes for organic pollutants are investigated. The water flux of hardwoods is significantly higher than that of softwood due to the existence of large vessel elements. For the single pollutant, both hardwood and softwood show high degradation efficiency for methylene blue and methylene orange, while the degradation efficiency of the softwoods for 4-nitrophenol is significantly higher than that of the hardwoods due to their lower water flux. For the mixed pollutants, all the wood membranes have a good degradation property for different concentrations of methylene blue in polluted water, while the degradation efficiency of high concentration methylene orange and 4-nitrophenol is low. Our work will provide some guidance for the degradation of organic pollutants in actual polluted water.

CQDs/biochar from reed straw modified Z-scheme MgIn2S4/BiOCl with enhanced visible-light photocatalytic performance for carbamazepine degradation in water.

The application of environmental-friendly and sustainable green materials in constructing photocatalysts to degrade pharmaceuticals and personal care products (PPCPs) attracts more attention. Herein, biochar (BC) or biomass carbon quantum dots (CQDs) were used to modify MgIn2S4/BiOCl (MB) heterojunction photocatalyst with Z-scheme structure, and improved the photocatalytic degradation performance for carbamazepine (CBZ) in the aqueous solution. Both BC and CQDs could form electron transfer interface with MB heterojunction, resulting in the photodegradation rate of MgIn2S4/BiOCl/CQDs (MBC, 96.43%) and MgIn2S4/BiOCl/BC (MBB, 88.09%) to CBZ within 120 min visible-light irradiation, which were significantly higher than that of MB (65.84%). Moreover, photoelectrochemical and photoluminescence tests verified that CQDs could act as a bridge for storing and transferring electrons in the entire Z-scheme system. Thence, compared with MBB, MBC could produce more •OH and •O2- under the visible light, which was indicated by the results of radical quenching experiments and electron paramagnetic resonance. Interestingly, under the natural sunlight, the photocatalytic performance of MBC to CBZ was even better than under laboratory conditions. In addition, the TOC removal efficiencies of MBB and MBC could reach 85.09% and 93.79% respectively, and ECOSAR program was utilized to further evaluate the eco-toxicity of CBZ and the intermediates towards fish, daphnid, and green algae, indicating that the photocatalytic process involving MBB and MBC showed outstanding toxicity reduction performance. Finally, compared with other composites, MBB and MBC showed higher photocatalytic performance and lower energy consumption, which would provide a green strategy for biochar materials in the photocatalytic treatment of PPCPs in water.

A Universal Method for Enhancing the Structural Stability of Ni-Rich Cathodes Via the Synergistic Effect of Dual-Element Cosubstitution.

Ni-rich layered cathodes suffer detrimental structural changes due to irreversible phase transformation (IPT). Precisely surface structural reconstruction through foreign element doping is a potential method to alleviate IPT propagation. The structure of surface reconstructed layer is greatly determined by the foreign element content and species. Herein, small doses of Ti and Al were co-substituted in LiNi0.92Co0.08O2 to synergistically regulate the surface reductive Ni distribution, consequently constructing thin rock salt phase at the particle surface. This homogeneous rock salt phase combined with the strong Ti-O and Al-O bonds generated a reversible H2-H3 phase transition and further eliminated IPT propagation. Moreover, the suppressed IPT propagation converted the two-phase (H2 and H3) coexistence to a quasi-single-phase transition. This eliminated the strong internal strains caused by a significant lattice mismatch. The Ti and Al co-substituted LiNi0.92Co0.08O2 exhibited outstanding capacity retention and excellent structural stability. Similar improvements were observed with W or Zr and Al cosubstitution in Ni-rich layered cathodes. This study proposes a universal method for comprehensive improvement of structural stability based on the synergistic effect of dual-element cosubstitution in Ni-rich layered oxide cathodes, which is being explored for production of high-cycle-stability lithium-ion batteries.

Visible-LED-light-driven photocatalytic degradation of ofloxacin and ciprofloxacin by magnetic biochar modified flower-like Bi2WO6: The synergistic effects, mechanism insights and degradation pathways.

Bi2WO6 possesses good stability but poor photocatalytic activity under visible light. Herein, the coupling of Bi2WO6, Fe3O4 and biochar (Bi2WO6/Fe3O4/BC) was investigated to enhance the photocatalytic performance of Bi2WO6 through facile hydrothermal method, which almost completely degraded ofloxacin (OFL) and ciprofloxacin (CIP) within 30 min under energy-saving visible LED irradiation. The superior photocatalytic activity of Bi2WO6/Fe3O4/BC was ascribed to the stronger visible light adsorption capacity and the lower recombination of electron-hole pairs. O2- played a major role during the photocatalytic reaction. The characterization results suggested that the introduction of biochar avoided the agglomeration of Bi2WO6 microspheres and Fe3O4 nanoparticles, at the same time, the biochar participated in OFL and CIP photodegradation by consuming different oxygen-containing functional groups. In order to further evaluate the application potential of Bi2WO6/Fe3O4/BC, the effects of environment factors and the application in different actual water were carefully investigated. Various transformation products and the possible degradation pathways of OFL and CIP were analyzed based on high resolution mass spectrometry (HRMS) results, moreover, the toxicity evaluation results of Escherichia coli indicated these intermediates products were less toxic compared OFL and CIP. Overall, Bi2WO6/Fe3O4/BC can provide a potential way for the application of photocatalytic technology in ambient wastewater purification.

Fabrication of vessel-like biochar-based heterojunction photocatalyst Bi2S3/BiOBr/BC for diclofenac removal under visible LED light irradiation: Mechanistic investigation and intermediates analysis.

In this work, a novel, economical and effective vessel-like biochar-based photocatalyst Bi2S3/BiOBr/BC was synthesized by a facile one-pot solvothermal method for the first time. A series of characterization analyses demonstrated the successful preparation of photocatalyst Bi2S3/BiOBr/BC. Furthermore, diclofenac (DCF) as the target contaminant was applied to elucidate the enhanced photocatalytic performance (93.65%, 40 min) under energy-saving visible LED light irradiation. Comparison experiments among different photocatalysts and photoelectrochemical tests results illustrated that excellent photocatalytic performance of Bi2S3/BiOBr/BC 10% might be attributed to the electrons transfer of biochar and higher charge separation efficiency of heterojunction structure. Besides, lower electrical energy per order value indicated photocatalyst/visible LED light system was more energy-saving. Proper photocatalyst dosage (0.6 g/L) and relatively acidic water environment (pH = 5.0) would be beneficial to DCF photodegrdation by Bi2S3/BiOBr/BC. Good reusability and stability of Bi2S3/BiOBr/BC were verified via five consecutive recycle experiments. Furthermore, the role of active species was determined through trapping experiments and O2- and h+ dominated the photodegradation reaction to mineralize DCF molecules. Eleven main intermediates and four possible photodegradation pathways were proposed by HRMS analysis. Accordingly, photocatalyst Bi2S3/BiOBr/BC would provide potential technical support for emerging pollutant removal in water matrix.

Effective removal of two fluoroquinolone antibiotics by PEG-4000 stabilized nanoscale zero-valent iron supported onto zeolite (PZ-NZVI).

In this work, nanoscale zero-valent iron (NZVI) was synthesized via liquid phase reduction method with surfactant polyethylene glycol (PEG-4000) modified and supported onto zeolite to prepare PZ-NZVI composite. SEM-EDS, XPS, BET.etc. characterizations indicated that the sphere NZVI particles were loaded on the zeolite successfully and the aggregation was restrained. The adsorption performance of PZ-NZVI for norfloxacin (NOR) or ofloxacin (OFL), two typical fluoroquinolones (FQs), from water was conducted. The equilibrium studies were demonstrated using Langmuir, Freundlich, Temkin and Elovich isotherms and better agreement was attained with the Temkin model. Compared with NZVI and zeolite, PZ-NZVI had higher FQs removal efficiency, and the Langmuir maximum adsorption capacity was 54.67 mg g-1 (NOR) and 48.88 mg g-1 (OFL). The kinetic parameters displayed that two FQs adsorption onto PZ-NZVI followed pseudo-second-order kinetic model. The thermodynamic analysis suggested the adsorption process was spontaneous and exothermic. In addition, the adsorption tests were executed at different influence factors and the adsorbent PZ-NZVI was suitable for a wide pH range (4-10) with the FQs (10 mg L-1) removal efficiency above 90% in 1 h. Furthermore, it was found that PZ-NZVI can be effortlessly separated from mixed solutions using external magnetic field. Finally, the process of FQs adsorbed onto PZ-NZVI was attributed to the surface complexion (forming bidentate complexes), hydrophobic interaction, pore filling and electrostatic interaction.

Research on quantitative measurement method of articular cartilage thickness change based on MR image.

In order to study the quantitative measurement method of articular cartilage thickness change based on MR image, 140 patients with no knee joint symptoms and 17 patients with knee joint damage were studied. FLASH, SE and FISP 3 sequences were scanned for all normal knee joints to determine the articular cartilage thickness. 17 patients with knee joint damage were followed up for six months. The thickness of their femoral condyle and femoral trochlea cartilage was measured by FLASH sequence and thickness changes are recorded. The results show that the thickness distribution of normal knee articular cartilage in different parts is not equal, and the thickness of articular cartilage will be gradually thinner in different ages; MR image technique can observe the change of articular cartilage thickness in patients with knee joint damage, reflecting the recovery status of the patient's condition. The results of quantitative measurement of changes in articular cartilage thickness based on MR images are presented herein, and the results are as expected. Experimental data were provided for the clinical treatment of acute knee injury and osteoarthritis. Although there are still some shortcomings in the research process, the research results still provide some reference and guidance for the future exploration of the use of MR images to monitor the condition of arthritis, so this study is a significant research topic.

Improving the Structure Stability of LiNi0.8Co0.1Mn0.1O2 by Surface Perovskite-like La2Ni0.5Li0.5O4 Self-Assembling and Subsurface La3+ Doping.

The commercialization of high-capacity Ni-rich cathode LiNi0.8Co0.1Mn0.1O2 is still hindered by some defects, such as moderate rate property and inferior high-voltage cycling stability. The main reason is that the structural transformation starts at the surface from layered to spinel and then to the rock salt phase, which will be aggravated under a higher voltage and gradually spread to the bulk region during cycling. Here, we fabricate the LiNi0.8Co0.1Mn0.1O2 surface with the perovskite-like La2Ni0.5Li0.5O4, which possesses good thermostability and Li+-ion diffusion kinetics, to strengthen its surface and subsurface lattice stability. First-principles theory has confirmed the well compatibility of La2Ni0.5Li0.5O4 with LiNi0.8Co0.1Mn0.1O2, thus affording unimpeded channels for fast Li+-ion transport in the same dimensions through these two crystal lattices. On the other hand, during the high-temperature synthesis process, La3+ ions are also doped into the subsurface lattice of LiNi0.8Co0.1Mn0.1O2. After La modification with the two above-mentioned effects, the structure stability of LiNi0.8Co0.1Mn0.1O2 at high operating voltages and after long cycles has been significantly enhanced. Specifically, at 2.75-4.5 V, the first discharge capacity at 0.2C of the La-modified sample is 229.3 mAh g-1 and the 200th capacity retention ratio at 1C has been improved from 63.7 to 90.1%.

Construction of carbon-doped supramolecule-based g-C3N4/TiO2 composites for removal of diclofenac and carbamazepine: A comparative study of operating parameters, mechanisms, degradation pathways.

An eco-friendly 2D heterojunction photocatalyst composites (BCCNT) consisting of carbon-doped supramolecule-based g-C3N4 (BCCN) layers and TiO2 nanoparticles has been fabricated via an in-situ method. Based on the SEM and XPS results affirmed that the coaction of doped carbon and supramolecule precursors lead to the different morphology of pure g-C3N4, C-doped g-C3N4 have improved the photodegradation diclofenac (DCF) and carbamazepine (CBZ). And the degradation efficiencies of DCF and CBZ could reach 98.92% and 99.77%, which were separately corresponded to 30 min (min) and 6 h (h) of LED lamp illumination. Additionally, the effects of catalysis dosage, solution pH, natural organic matter (NOM), inorganic anions (Cl-, SO42-, NO3-) and different water matrices were deeply investigated. The scavenger experiments demonstrated that •O2-, h+ were main active species under visible irradiation. Furthermore, the photodegradation pathways of DCF and CBZ were detected by high-resolution mass spectrometry (HRMS) instruments and three-dimensional excitation-emission matrix fluorescence spectra (3D EEMs). Eventually, the possible photocatalytic mechanisms of BCCNT were proposed.

A polydopamine-based molecularly imprinted polymer on nanoparticles of type SiO2@rGO@Ag for the detection of λ-cyhalothrin via SERS.

A new method is described for the determination of the pesticide λ-cyhalothrin (LC). It combines SERS detection with molecular imprinting and largely improves selectivity. A multilayer surface imprinted nanocomposite was synthesized in two steps on a nanostructure of type SiO2@rGO@Ag acting as a substrates. Firstly, the surface of the SiO2@rGO@Ag composite was modified with self-polymerized dopamine. Secondly, surface-initiated polymerization was carried out to prepare a molecularly imprinted polymer (MIP) using LC as the template. The use of this SiO2@rGO@Ag-MIP allows for excellent SERS based detection and has high selectivity for LC. The Raman intensity and LC concentration present perfect linear relationship between 10-5 to 10-9 mol L-1 and the detection limit is 3.8×10-10 mol L-1. All the procedures are conducted in aqueous or ethanol solution. Graphical abstract Schematic of a new method for determination of the pesticide λ-cyhalothrin. It combines SERS detection with molecular imprinting and largely improves selectivity. A multilayer surface imprinted nanocomposite was synthesized in two steps on a nanostructure of type SiO2@rGO@Ag acting as a substrates.

Thermo-responsive molecularly imprinted sensor based on the surface-enhanced Raman scattering for selective detection of R6G in the water.

In this study, a novel SERS sensor was successfully prepared by combining a molecular imprinted technique (MIT) with a SERS technique to improve the selectivity of the traditional SERS technique. Moreover, a thermo-sensitive technique was also introduced to confer stimuli-responsive properties to the materials. In a typical procedure, the Ag nanoparticles (NPs) were reduced on the surface of ZnO nanorods (NRs), and the ZnO/Ag heterostructures were used as the SERS substrates. Subsequently, a layer of thermo-sensitive imprinted polymer was coated on the surface of ZnO/Ag heterostructures to prepare the thermoresponsive ZnO/Ag/molecularly imprinted polymers (ZOA-TMIPs) by precipitation polymerization. Moreover, it was proven that the ZOA-TMIPs were regenerable and exhibited good reusability. The results proved that the materials in this study can be effectively used for residual organic dye detection in water.

Preparation of a self-cleanable molecularly imprinted sensor based on surface-enhanced Raman spectroscopy for selective detection of R6G.

Novel molecularly imprinted polymers (MIPs) based on the technique of surface-enhanced Raman scattering (SERS) were successfully prepared. Firstly, ZnO nanorods were fabricated with Ag by reduction of Ag+ on the surface of the ZnO nanorods. Then, ZnO/Ag heterostructures were used as the substrate, rhodamine 6G was used as the template molecule, acrylamide was used as the functional monomer, ethylene glycol dimethacrylate was used as the cross-linker, and 2,2'-azobis(2-methylpropionitrile) was used as the initiator to prepare the ZnO/Ag MIPs (ZOA-MIPs). Through characterization analysis, it was proved that the novel ZOA-MIPs exhibited excellent SERS properties and selectivity. Under the optimal conditions, there was a good linear relationship (R 2 = 0.996) between the Raman signal (at 1654 cm-1) and the concentration of the templates, and the detection limit was 10-13 mol L-1. It was also proved that the ZOA-MIPs had the property of self-cleaning, resulting in good reusability. It is envisaged that the sensitivity of SERS coupled with the selectivity of MIPs could result in a promising chemosensor for practical applications.

A high performance and highly-controllable core-shell imprinted sensor based on the surface-enhanced Raman scattering for detection of R6G in water.

A novel, sensitive sensor material combined the technique of surface enhance Raman scattering (SERS) and molecular imprinting was prepared. It was used the amino-functionalized SiO2 nanospheres as the supporting materials and anchored Ag nanoparticles on the surface by the function of coordination between Ag+ and NH2-. Then, it was used that the Rhodamine 6G (R6G) as the template, acrylamide (AM) as functional monomer, ethyleneglycol dimethacrylate (EGDMA) as cross-linker, 2,2'-azobis(2-methylpropionitrile) (AIBN) as initiator to prepare the core-shell molecular imprinted polymers. Prominently, the shell thickness could be controlled by the regulation of cross-linker dosage and it was found that the SERS detection signal was most obvious when the shell thickness was about 40nm. Under the optimal condition, it was presented good linear relationship (R2=0.93) between the Raman signal (at 1505cm-1) and the concentration of the templates and the limit of detection was 10-12molL-1. Meanwhile, the selective experiment was proved that this materials owned specific selectivity to the template. It was confirmed that the core-shell molecular imprinted polymers were a kind of highly sensitive and selective sensor materials in the field of R6G detection.

[Renal protection of Tangke Decoction on rats with diabetes and its effect on the expression of TGF-beta1/Smad4].

OBJECTIVE: To observe the effect of Tangke Decoction (TD) on the expression of TGF-beta1/Smad4 of rats with early diabetes and to explore the effect and mechanism of TD against the renal injury induced by diabetes. METHODS: SD rats were randomly divided into the normal control group (n = 12), the model group (n = 10), the Chinese herbs prevented group (n =10), the Chinese herbs treated group (n = 10), and the Western medicine control group (n = 10). TD (18 mg/kg) was given by gastrogavage to rats in the Chinese herbs prevented group immediately after successful modeling for 12 weeks, once daily. At the 4th week of successful modeling, rats in the rest 4 groups were administered by gastrogavage. Equal volume of normal saline was given to rats in the model group and the normal control group. Benazepril suspension (1 mg/kg) was administered by gastrogavage to rats in the Western medicine control group for 8 weeks, once daily. TD (18 mg/kg) was given by gastrogavage to rats in the Chinese herbs treated group for 8 weeks, once daily. The body weight, kidney weight, index of kidney weight, fasting blood sugar, 24 h urinary albumin excretion rate were examined after experiment. The pathological changes of the renal tissue were observed by HE staining, Masson staining, and electron microscope. The expression of renal transforming growth factor-beta1, (TGF-beta1) and Smad4 were detected using immunohistochemical assay. RESULTS: Compared with the normal control group, the body weight of rats decreased significantly; the kidney weight, index of kidney weight, blood sugar, 24 h urinary protein excretion, the urinary albumin excretion rate,TGF-beta1 and Smad4 expression increased significantly in the model group (all P < 0.01). Compared with the model group, the aforesaid indices were improved in each treatment group with statistical difference (P < 0.05, P < 0.01). Compared with the Western medicine control group, the kidney weight, index of kidney weight, blood sugar, 24 h urinary protein excretion, and the urinary albumin excretion rate were obviously improved in the Chinese herbs prevented group (P < 0.01). The renal pathological changes were most obvious in the model group significantly, but they were improved in all treatment groups. CONCLUSION: TD could obviously improve the symptoms of diabetes and down-regulate the expression of renal TGF-beta1 and Smad4 of early diabetic nephropathy rats, which suggested that TD had certain preventive effect on early diabetic nephropathy.