Coating CoFe2O4 shell on Fe particles to increase the utilization efficiencies of Fe and peroxymonosulfate for low-cost Fenton-like reactions.

Bimetallic composites (Fe@CoFe2O4) with zero-valent Fe as the core encapsulated by CoFe2O4 layers are synthesized by a coprecipitation-calcination method, which are applied to activate PMS for the degradation of bisphenol A (BPA). Enhanced activity of Fe@CoFe2O4 is achieved with very fast degradation rate (kobs = 0.5737 min-1). In the fixed-bed reactor, the catalyst lifetime (tul) of Fe@CoFe2O4 is determined to be 22 h compared to 11 h of Fe, and the deactivation rate constant (kd) for Fe@CoFe2O4 is 0.0083 mg·L-1·h-1, only ∼1/10 of Fe (0.0731). The XPS results indicate that the core-shell structure of Fe@CoFe2O4 could promote the redox cycles of Co3+/Co2+ and Fe3+/Fe2+. It is proved that the coating of CoFe2O4 shell on Fe0 can protect the Fe0 core from being oxidized by PMS to form passivation layer. The electrons of Fe0 can therefore be used effectively for activating PMS to produce ROSs via the CoFe2O4 shell. This modification method of Fe0 would decrease the cost of PMS based wastewater remediation greatly, thus should have great potential on an industrial scale.

Field Measurements of Wind-Induced Responses of the Shanghai World Financial Center during Super Typhoon Lekima.

In this paper, the wind-induced responses of the Shanghai World Financial Center (SWFC) under Super Typhoon Lekima are measured using the health monitoring system. Based on the measurements, the characteristics of vibration, including probability density distribution of accelerations, power spectra, and mode shapes are studied. The curve method and the standard deviation method are used to analyze the relationship of the first- and second-order natural frequencies and damping ratios with amplitudes and the mean wind speed. The results show the following: (1) The structural wind-induced responses in the X and Y directions have high consistencies, and the vibration signals exhibit a peak state; moreover, response amplitudes and acceleration signals disperse when the floor height increases. (2) The first- and second-order natural frequencies in the X and Y directions decrease with the increasing amplitudes and are negatively correlated with mean wind speed; the maximum decrease in natural frequency is 5.794%. The first- and second-order damping ratios in the X and Y directions increase with the increasing amplitudes and are positively correlated with the mean wind speed; the maximum increase in damping ratio is 95.7%. (3) The curve method and the standard deviation method are similar in identifying dynamic characteristic parameters, but the discreteness of the natural frequencies obtained by the curve method is lesser. (4) Under excitations of various typhoons, the mode shapes of SWFC are basically the same, and the mode shapes in the X and Y directions increase with the height and have nonlinearity.

A plan verification platform for online adaptive proton therapy using deep learning-based Monte-Carlo denoising.

BACKGROUND PURPOSE: This study focused on developing a fast Monte Carlo (MC) plan verification platform via a deep learning (DL)-based denoising approach. It can maintain the MC dose calculation accuracy while significantly reducing the computation time. We also investigated its potential applications for online adaptive proton therapy (APT). METHODS: First, we modeled an MC platform for proton therapy using the beam data library (BDL) required for treatment planning systems and then tested it with measured data. To accelerate the dose calculation, a dl-based denoising model with deep ResNet-deconvolution networks was developed. It was trained on the MC dose distribution of tumor sites obtained from 52 patients. The input MC dose distribution was with 1 × 106 simulated protons and the reference was 1 × 108. Fivefold cross-validation was performed. RESULTS: Comparing the MC model with measured data, the range agreement (point-to-point difference) was better than 0.85 mm, and the lateral dose profile difference was below 2.41 %. For the denoising approach, we found a significant improvement in the dose volume histogram (DVH) for predicted images compared with input images. The root mean squared error (RMSE) for predicted versus reference images was 3.94 times lower than that of the input versus reference images. Moreover, for the gamma passing rate (3 mm/3%), the predicted versus reference images have an average of 99 %, much higher than the 82 % of the input versus reference images. The MC model successfully denoised the test dose map (high noise) to approach the reference (low noise). The elapsed time can be reduced to < 60 s (simulation time [high noise] + predicted time), much lower than the simulation time of a low noise dose map (e.g., >100 min of simulation of 1 + E8 particles). CONCLUSIONS: We propose an analogous end-to-end fast plan verification platform using the combination of MC and DL methods. The platform yields dose calculation accuracy similar to MC codes while significantly reducing the elapsed time and can be used for online APT as an alternative to online plan verification.

Distribution of ecological restoration projects associated with land use and land cover change in China and their ecological impacts.

China is prone to broad land degradation and thus has been implementing ecological restoration projects (ERPs) since the reform and opening up. The extent of ERPs, as well as the varied planting efforts including tree gain projects (TGPs), grass gain projects (GGPs), and shrub gain projects (SGPs), have remained largely unknown. In addition, the mixed success of ERPs on preventing soil erosion and improving biodiversity is not well known. Based on a land use and land cover (LULC) product and a trajectory-based change detection approach, we successfully generated the first national map of ERPs associated with land use and land cover change (LUCC) and its three associated subcategories. Then, we applied the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model to evaluate the dynamics of sediment retention and habitat quality. In addition, we explored the heterogeneous patterns for the ecological impacts of ERPs. Our results suggested that during the past 40 years, a total ERP area of 9.54 × 106 hm2 was observed nationwide, mainly in the northwestern provinces of China. Of the three ERP subcategories, TGPs accounted for the largest area (48.55%), followed by GGPs (47.50%) and SGPs (3.96%). The national average sediment retention experienced a significant increase, whereas the national average habitat quality experienced a significant decline. ERP-driven increases in habitat quality were offset partly by the LUCCs induced by economic development policies in some regions, especially in northeast China. The simultaneous effect of construction land expansion and ERP implementation on sediment retention made the synchronization between ERP implementation and sediment retention improvement insignificant. We also suggested the optimal direction for ERP implementation.

Hierarchical N-Doped CuO/Cu Composites Derived from Dual-Ligand Metal-Organic Frameworks as Cost-Effective Catalysts for Low-Temperature CO Oxidation.

Development of multi-ligand metal-organic frameworks (MOFs) and derived heteroatom-doped composites as efficient non-noble metal-based catalysts is highly desirable. However, rational design of these materials with controllable composition and structure remains a challenge. In this study, novel hierarchical N-doped CuO/Cu composites were synthesized by assembling dual-ligand MOFs via a solvent-induced coordination modulation/low-temperature pyrolysis method. Different from a homogeneous system, our heterogeneous nucleation strategy provided more flexible and cost-effective MOF production and offered efficient direction/shape-controlled synthesis, resulting in a faster reaction and more complete conversion. After pyrolysis, they further transformed to a unique metal/carbon matrix with regular morphology and, as a hot template, guided the orderly generation of metal oxides, eliminating sintering and agglomeration of metal oxides and initiating a synergistic effect between the N-doped metal oxide/metal and carbon matrix. The prepared N-doped CuO/Cu catalysts held unique water resistance and superior catalytic activity (100% CO conversion at 140 °C).

Rapid and cost-effective screening of CRISPR/Cas9-induced mutants by DNA-guided Argonaute nuclease.

OBJECTIVE: With the widespread application of CRISPR/Cas9 gene editing technology, new methods are needed to screen mutants quickly and effectively. Here, we aimed to develop a simple and cost-effective method to screen CRISPR/Cas9-induced mutants. RESULT: We report a novel method to identify CRISPR/Cas9-induced mutants through a DNA-guided Argonaute nuclease derived from the archaeon Pyrococcus furiosus. We demonstrated that the Pyrococcus furiosus Argonaute (PfAgo)-based method could distinguish among biallelic mutants, monoallelic mutants and wild type (WT). Furthermore, this method was able to identify 1 bp indel mutations. CONCLUSION: The PfAgo-based method is simple to implement and can be applied to screen biallelic mutants and mosaic mutants generated by CRISPR-Cas9 or other kinds of gene editing tools.

Dose calculation in proton therapy using a discovery cross-domain generative adversarial network (DiscoGAN).

PURPOSE: Accurate dose calculation is a critical step in proton therapy. A novel machine learning-based approach was proposed to achieve comparable accuracy to that of Monte Carlo simulation while reducing the computational time. METHODS: Computed tomography-based patient phantoms were used and three treatment sites were selected (thorax, head, and abdomen), comprising different beam pathways and beam energies. The training data were generated using Monte Carlo simulations. A discovery cross-domain generative adversarial network (DiscoGAN) was developed to perform the mapping between two domains: stopping power and dose, with HU values from CT images incorporated as auxiliary features. The accuracy of dose calculation was quantitatively evaluated in terms of mean relative error (MRE) and mean absolute error (MAE). The relationship between the DiscoGAN performance and other factors such as absolute dose, beam energy and location within the beam cross-section (center and off-center lines) was examined. RESULTS: The DiscoGAN model is found to be effective in dose calculation. For the abdominal case, the MRE is found to 1.47% (mean), 3.30% (maximum) and 0.67% (minimum). For the thoracic case, the MRE is found to ~2.43% (mean), 4.80% (maximum) and 0.71% (minimum). For the head case, the MRE is found to ~2.83% (mean), 4.84% (maximum) and 1.01% (minimum). Comparable accuracy is found in the independent validation dataset (different CT images), achieving a mean MRE of ~1.65% (thorax), 4.02% (head) and 1.64% (abdomen). For the energy span between 80 and 130 MeV, no strong dependency of accuracy on beam energy is found. The results imply that no systematic deviation, either over-dose or under-dose, occurs between the predicted dose and raw dose. CONCLUSION: The DiscoGAN framework demonstrates great potential as a tool for dose calculation in proton therapy, achieving comparable accuracy yet being more efficient relative to Monte Carlo simulation. Its comparison with the pencil beam algorithm (PBA) will be the next step of our research. If successful, our proposed approach is expected to find its use in more advanced applications such as inverse planning and adaptive proton therapy.

Proton FLASH: passive scattering or pencil beam scanning?

This study focused on a direct comparison of dose delivery efficiency between two proton FLASH delivery modes: passive scattering and pencil beam scanning (PBS). Monte-Carlo simulation of the beamline was performed using the Geant4 package. Two proton energies (63 and 230 MeV) were selected, targeting for shallow and deep-seated tumors, respectively. Two irradiation field sizes were selected: 13 × 13 mm2 and 50 × 50 mm2. For each delivery mode, two cases were investigated: shoot-through and Bragg peak, yielding a total of 4 delivery scenarios. For the passive scattering mode, the impact on dose rate by multiple components along the beamline were investigated, including ridge-filter, scatterer, range shifter and collimator. A quantitative comparison among four scenarios was made in terms of field size, dose, dose rate and treatment plan quality (dose volume histogram). For the 230 MeV case, the dose rate (for 1 nA current) is 0.05 Gy s-1 (passive with Bragg peak, field size: 50 × 50 mm2) and 2.6 Gy s-1 (PBS with shoot-through). Dose rate comparison is made between passive scattering and PBS as the delivery changes from spot-layer to shoot-through. In conclusion, the study successfully established a benchmark reference for dose rate performance for different scenarios, taking into account components along the beamline, field size and beam current. The results allow us to predict and compare the required beam current to yield a dose rate sufficiently high, above the threshold of the FLASH effect.

ASSESSMENT OF OCCUPATIONAL EXPOSURE OF RADIATION WORKERS AT A TERTIARY HOSPITAL IN ANHUI PROVINCE, CHINA, DURING 2013-18.

Data on occupational radiation exposure of radiation workers at a tertiary hospital in China during 2013-18 were analyzed to provide decision-making advice for hospitals and health administrative departments. A total of 1255 exposure records of radiation workers were collected. The average annual effective doses of radiation workers during 2013-18 was 0.4977 mSv, with 1150 (91.63%) records ranging between 0 and 1 mSv, 91 (7.25%) between 1 and 2 mSv, 10 (0.80%) between 2 and 5 mSv and 4 (0.32%) records exceeding 5 mSv. There was a significant difference in the average annual effective dose of radiation workers among different occupational categories except in 2015 indicating that hospitals and administrative authorities should pay more attention to the radiation workers in the nuclear medicine and intervention department. The average annual effective doses did not show significant differences between male and female workers except in 2017; in that year the average individual dose of female workers was higher than male workers'. There were no significant differences in the average annual effective doses among doctors, nurses and radiologic technologists except in 2016 and 2017; during that period the individual dose of nurses was higher than doctors' and radiologic technologists'.

Assessment of Clofazimine and TB47 Combination Activity against Mycobacterium abscessus Using a Bioluminescent Approach.

Mycobacterium abscessus is intrinsically resistant to most antimicrobial agents. The emerging infections caused by M. abscessus and the lack of effective treatment call for rapid attention. Here, we intended to construct a selectable marker-free autoluminescent M. abscessus strain (designated UAlMab) as a real-time reporter strain to facilitate the discovery of effective drugs and regimens for treating M. abscessus The UAlMab strain was constructed using the dif/Xer recombinase system. In vitro and in vivo activities of several drugs, including clofazimine and TB47, a recently reported cytochrome bc1 inhibitor, were assessed using UAlMab. Furthermore, the efficacy of multiple drug combinations, including the clofazimine and TB47 combination, were tested against 20 clinical M. abscessus isolates. The UAlMab strain enabled us to evaluate drug efficacy both in vitro and in live BALB/c mice in a real-time, noninvasive fashion. Importantly, although TB47 showed marginal activity either alone or in combination with clarithromycin, amikacin, or roxithromycin, the drug markedly potentiated the activity of clofazimine, both in vitro and in vivo This study demonstrates that the use of the UAlMab strain can significantly facilitate rapid evaluation of new drugs and regimens. The clofazimine and TB47 combination is effective against M. abscessus, and dual/triple electron transport chain (ETC) targeting can be an effective therapeutic approach for treating mycobacterial infections.

[The value of autofluorescence bronchoscopy in assessment of tumor extent and guide of therapeutic strategy in central lung cancer].

OBJECTIVE: To determine the sensitivity of autofluorescence bronchoscopy (AFB) in the assessment of tumor size and therapeutic strategy. METHODS: Patients with imaging suspected of malignancy were examined with both white light bronchoscopy (WLB) and AFB. The area of tumor infiltration, imaging information and pathological results were analyzed. RESULTS: A total of 212 patients were enrolled, including 180 male and 32 female. In 24 patients (13.2%), greater tumor volume was revealed by AFB than by WLB alone. In these patients, the median diameter of tumor was >1 cm wider on AFB examination than on WLB. Therapeutic strategy was changed in 18 patients (9.9%) after receiving AFB, including 15 patients with expanded scope of removal and 3 patients with avoidance of surgery. In the univariate analysis, the pathological type of squamous cell carcinoma and tumor invasion in two or more segments of bronchus were independent predictive factors. Diagnostic sensitivity of AFB group was 85.7%, specificity 73.3%, positive predictive value 95.1%, false predictive value 45.8%. Diagnostic sensitivity of WLB group was 72.5%, specificity 60.0%, positive predictive value 91.7%, false predictive value 26.5%. CONCLUSION: Our study suggests that compared with WLB alone, autofluorescence bronchoscopy plus WLB significantly improves the diagnostic value and treatment outcome of central lung cancer.

[Narrow-band imaging bronchoscopy improves assessment of tumor extent and affects therapeutic strategy for central lung cancer].

OBJECTIVE: To determine the sensitivity of narrow-band imaging bronchoscopy (NBI) in the assessment of tumor extent and therapeutic strategy. METHODS: A total of 196 patients with imaging abnormalities for malignancy were examined with both white light bronchoscopy (WLB) and NBI (Olympus, EVIS LUCERA). Record the tumor infiltration, image and pathological results. RESULTS: There were 152 male and 44 female with a mean age of 58 years. In 22 patients (13.1%), NBI revealed greater tumor extent than WLB alone. And tumor margins were >1 cm wider on NBI examination than on WLB. In 19 patients (11.3%), that finding influenced further therapeutic course, leading to greater resection level (n = 14) or avoidance of surgery (n = 5). According to univariate analysis, tumor size > 30 mm and pathological type of squamous cell carcinoma were independent predictive factors (OR 3.13, 95% CI: 1.06-9.21, P = 0.038; OR 4.68, 95% CI: 1.02-21.58, P = 0.048). The diagnostic sensitivity of NBI group was 88.2%, specificity 83.3%, positive predictive value 98.1% and false predictive value 41.7%. And the diagnostic sensitivity of WLB group was 80.3%, specificity 55.6%, positive predictive value 94.7% and false predictive value 22.2%. CONCLUSIONS: The combined use of NBI bronchoscopy and conventional white-light examination has greater sensitivity and specificity for assessing tumor margins. And this technique also significantly improves the assessment of central lung cancer infiltration and influences the therapeutic strategy.

Producing cell-free culture broth of rhamnolipids as a cost-effective fungicide against plant pathogens.

Biosurfactants of rhamnolipids have been enthusiastically investigated for substitutes of synthetic agrochemicals against plant pathogens. However, all such studies have been conducted on rhamnolipids with high purity which have limitations due to high costs. This paper focused on the applicability of rhamnolipid-containing cell-free culture broth. It was found that rhamnolipids in cell-free culture broth of Pseudomonas aeruginosa ZJU211 were largely composed of di-rhamnolipid and mono-rhamnolipid with the ratio varying with culture time. After 96 h of fermentation, the mass ratio of di-rhamnolipid over mono-rhamnolipid increased to 2.6:1. Crude rhamnolipids in a form of cell-free culture broth showed high antifungal activity against colony growth and biomass accumulation of seven plant pathogens comprising two Oomycetes, three Ascomycota and two Mucor spp. fungi, among which three plant pathogens were firstly reported in this paper showing inhibition to rhamnolipids. Particularly, rhamnolipids showed potent activity against two Oomycetes that acquire resistance to commercial compound of metalaxyal. Furthermore, di-rhamnolipid was elucidated to dominate the antifungal activity of crude rhamnolipids by in vitro studies. At last, the efficacy and safety of cell-free culture broth was preliminarily illustrated on plants in vivo. So cell-free culture broth as a crude rhamnolipid product could be served as a potential cost-effective and environmental-friendly fungicide in agriculture.