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1.
Molecules ; 29(12)2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38930834

ABSTRACT

Electrospinning is a cost-effective and flexible technology for producing nanofibers with large specific surface areas, functionalized surfaces, and stable structures. In recent years, electrospun nanofibers have attracted more and more attention in electrochemical biosensors due to their excellent morphological and structural properties. This review outlines the principle of electrospinning technology. The strategies of producing nanofibers with different diameters, morphologies, and structures are discussed to understand the regulation rules of nanofiber morphology and structure. The application of electrospun nanofibers in electrochemical biosensors is reviewed in detail. In addition, we look towards the future prospects of electrospinning technology and the challenge of scale production.


Subject(s)
Biosensing Techniques , Electrochemical Techniques , Nanofibers , Biosensing Techniques/methods , Nanofibers/chemistry , Electrochemical Techniques/methods , Nanotechnology/methods , Humans
2.
Small ; : e2402061, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38805742

ABSTRACT

Carbon-based CsPbI3 perovskite solar cells without hole transporter (C-PSCs) have achieved intense attention due to its simple device structure and high chemical stability. However, the severe interface energy loss at the CsPbI3/carbon interface, attributed to the lower hole selectivity for inefficient charge separation, greatly limits device performance. Hence, dipole electric field (DEF) is deployed at the above interface to address the above issue by using a pole molecule, 4-trifluoromethyl-Phenylammonium iodide (CF3-PAI), in which the ─NH3 group anchors on the perovskite surface and the ─CF3 group extends away from it and connects with carbon electrode. The DEF is proven to align with the built-in electric field, that is pointing toward carbon electrode, which well enhances hole selectivity and charge separation at the interface. Besides, CF3-PAI molecules also serve as defect passivator for reducing trap state density, which further suppresses defect-induced non-radiative recombination. Consequently, the CsPbI3 C-PSCs achieve an excellent efficiency of 18.33% with a high VOC of 1.144 V for inorganic C-PSCs without hole transporter.

3.
Nanomaterials (Basel) ; 14(6)2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38535695

ABSTRACT

Nowadays, two of the biggest obstacles restricting the further development of methanol fuel cells are excessive cost and insufficient catalytic activity of platinum-based catalysts. Herein, platinum nanoparticle supported graphene aerogel (Pt/3DGA) was successfully synthesized by a one-step hydrothermal self-assembly method. The loose three-dimensional structure of the aerogel is stabilized by a simple one-step method, which not only reduces cost compared to the freeze-drying technology, but also optimizes the loading method of nanoparticles. The prepared Pt/3DGA catalyst has a three-dimensional porous structure with a highly cross-linked, large specific surface area, even dispersion of Pt NPs and good electrical conductivity. It is worth noting that its catalytic activity is 438.4 mA/mg with long-term stability, which is consistent with the projected benefits of anodic catalytic systems in methanol fuel cells.. Our study provides an applicable method for synthesizing nano metal particles/graphene-based composites.

4.
Sci Bull (Beijing) ; 69(8): 1050-1060, 2024 Apr 30.
Article in English | MEDLINE | ID: mdl-38341351

ABSTRACT

Defects formed at the surface, buried interface and grain boundaries (GB) of CsPbI3 perovskite films considerably limit photovoltaic performance. Such defects could be passivated effectively by the most prevalent post modification strategy without compromising the photoelectric properties of perovskite films, but it is still a great challenge to make this strategy comprehensive to different defects spatially distributed throughout the films. Herein, a spatially selective defect management (SSDM) strategy is developed to roundly passivate various defects at different locations within the perovskite film by a facile one-step treatment procedure using a piperazine-1,4-diium tetrafluoroborate (PZD(BF4)2) solution. The small-size PZD2+ cations could penetrate into the film interior and even make it all the way to the buried interface of CsPbI3 perovskite films, while the BF4- anions, with largely different properties from I- anions, mainly anchor on the film surface. Consequently, virtually all the defects at the surface, buried interface and grain boundaries of CsPbI3 perovskite films are effectively healed, leading to significantly improved film quality, enhanced phase stability, optimized energy level alignment and promoted carrier transport. With these films, the fabricated CsPbI3 PSCs based on carbon electrode (C-PSCs) achieve an efficiency of 18.27%, which is among the highest-reported values for inorganic C-PSCs, and stability of 500 h at 85 °C with 65% efficiency maintenance.

5.
Chemistry ; 30(17): e202303594, 2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38278765

ABSTRACT

Graphene aerogel (GA) has important application potential as piezoresistive sensors due to its low density, high conductivity, high porosity, and good mechanical properties. However, the fabrication of GA-based sensors with good mechanical properties and excellent sensing performance is still challenging. Herein, liquid- metal-modified GAs (GA/LM) are proposed for the development of an excellent GA-based sensor. GA/LM with three-dimensional interconnected layered structure exhibits excellent compressive stress of 41 KPa and fast response time (<20 ms). While generally flexible GA composites cannot be compressed beyond 80 % strain without plastic deformation, GA/LM demonstrates a high compressive strength of 60 kPa under a strain of 90 %. A real-time pressure sensor was fabricated based on GA/LM-2 to monitor swallowing, pulse beating, finger, wrist and knee bending, and even plantar pressure during walking. These excellent features enable potential applications in health detection.

6.
Med Phys ; 51(1): 670-681, 2024 Jan.
Article in English | MEDLINE | ID: mdl-36939370

ABSTRACT

BACKGROUND: Ultra-high dose rate (FLASH) radiation has been reported to efficiently suppress tumor growth while sparing normal tissue; however, the mechanism of the differential tissue sparing effect is still not known. Oxygen has long been known to profoundly impact radiobiological responses, and radiolytic oxygen depletion has been considered to be a possible cause or contributor to the FLASH phenomenon. PURPOSE: This work investigates the impact of tissue pO2 profiles, oxygen depletion per unit dose (g), and the oxygen concentration yielding half-maximum radiosensitization (the average of its maximum value and one) (k) in tumor and normal tissue. METHODS: We developed a model that considers the dependent relationship between oxygen depletion and change of radiosensitivity by FLASH irradiation. The model assumed that FLASH irradiation depletes intracellular oxygen more rapidly than it diffuses into the cell from the extracellular environment. Cell survival was calculated based on the linear quadratic-linear model and the radiosensitivity related parameters were adjusted in 1 Gy increments of the administered dose. The model reproduced published experimental data that were obtained with different cell lines and oxygen concentrations, and was used to analyze the impact of parameter uncertainties on the radiobiological responses. This study expands the oxygen depletion analysis of FLASH to normal human tissue and tumor based on clinically determined aggregate and individual patient pO2 profiles. RESULTS: The results show that the pO2 profile is the most essential factor that affects biological response and analyses based on the median pO2 rather than the full pO2 profile can be unreliable and misleading. Additionally, the presence of a small fraction of cells on the threshold of radiobiologic hypoxia substantially alters biological response due to FLASH oxygen depletion. We found that an increment in the k value is generally more protective of tumor than normal tissue due to a higher frequency of lower pO2 values in tumors. Variation in the g value affects the dose at which oxygen depletion impacts response, but does not alter the dose-dependent response trends, if the g value is identical in both tumor and normal tissue. CONCLUSIONS: The therapeutic efficacy of FLASH oxygen depletion is likely patient and tissue-dependent. For breast cancer, FLASH is beneficial in a minority of cases; however, in a subset of well oxygenated tumors, a therapeutic gain may be realized due to induced normal tissue hypoxia.


Subject(s)
Neoplasms , Oxygen , Humans , Oxygen/metabolism , Radiation Tolerance , Neoplasms/radiotherapy , Radiobiology , Hypoxia
7.
Chem Commun (Camb) ; 59(73): 10996-10999, 2023 Sep 12.
Article in English | MEDLINE | ID: mdl-37615934

ABSTRACT

In this study, 2-fluoro-5-iodopyridine (2-F-5-IPy) was used as an electrolyte additive, which can not only protect the negative electrode effectively by forming a stable SEI, but also convert dead lithium into active lithium. Benefits from this are a capacity retention of a Li‖LiFePO4 cell after 300 cycles from 36.5% to 89.4%, and the symmetrical cell can work stably for more than 800 hours. Therefore, the addition of 2-F-5-IPy can effectively improve the performance of lithium metal batteries.

8.
Cancers (Basel) ; 15(8)2023 Apr 13.
Article in English | MEDLINE | ID: mdl-37190197

ABSTRACT

Ultra-high dose rate irradiation has been reported to protect normal tissues more than conventional dose rate irradiation. This tissue sparing has been termed the FLASH effect. We investigated the FLASH effect of proton irradiation on the intestine as well as the hypothesis that lymphocyte depletion is a cause of the FLASH effect. A 16 × 12 mm2 elliptical field with a dose rate of ~120 Gy/s was provided by a 228 MeV proton pencil beam. Partial abdominal irradiation was delivered to C57BL/6j and immunodeficient Rag1-/-/C57 mice. Proliferating crypt cells were counted at 2 days post exposure, and the thickness of the muscularis externa was measured at 280 days following irradiation. FLASH irradiation did not reduce the morbidity or mortality of conventional irradiation in either strain of mice; in fact, a tendency for worse survival in FLASH-irradiated mice was observed. There were no significant differences in lymphocyte numbers between FLASH and conventional-dose-rate mice. A similar number of proliferating crypt cells and a similar thickness of the muscularis externa following FLASH and conventional dose rate irradiation were observed. Partial abdominal FLASH proton irradiation at 120 Gy/s did not spare normal intestinal tissue, and no difference in lymphocyte depletion was observed. This study suggests that the effect of FLASH irradiation may depend on multiple factors, and in some cases dose rates of over 100 Gy/s do not induce a FLASH effect and can even result in worse outcomes.

9.
Molecules ; 28(8)2023 Apr 20.
Article in English | MEDLINE | ID: mdl-37110837

ABSTRACT

Disease-related biomarkers may serve as indicators of human disease. The clinical diagnosis of diseases may largely benefit from timely and accurate detection of biomarkers, which has been the subject of extensive investigations. Due to the specificity of antibody and antigen recognition, electrochemical immunosensors can accurately detect multiple disease biomarkers, including proteins, antigens, and enzymes. This review deals with the fundamentals and types of electrochemical immunosensors. The electrochemical immunosensors are developed using three different catalysts: redox couples, typical biological enzymes, and nanomimetic enzymes. This review also focuses on the applications of those immunosensors in the detection of cancer, Alzheimer's disease, novel coronavirus pneumonia and other diseases. Finally, the future trends in electrochemical immunosensors are addressed in terms of achieving lower detection limits, improving electrode modification capabilities and developing composite functional materials.


Subject(s)
Biosensing Techniques , COVID-19 , Humans , Immunoassay , Electrochemical Techniques , COVID-19/diagnosis , Biomarkers
10.
ACS Appl Mater Interfaces ; 15(14): 18516-18527, 2023 Apr 12.
Article in English | MEDLINE | ID: mdl-36996410

ABSTRACT

Collagen fibers (CFs) were previously used as packing materials for the separation of flavonoids based on hydrogen bond and hydrophobic interactions. However, as for flavonoid aglycones, CFs presented unsatisfactory adsorption capacity and separation efficiency due to the fact that they include limited hydroxyls and phenyls. In order to improve the adsorption capacity and separation efficiency, the hydrophobic modification strategy was employed in this research to enhance the hydrophobic interaction of CF with flavonoid aglycones by using silane coupling agents with different alkyl chains (isobutyl, octyl, and dodecyl). FT-IR analysis, DSC, TG, SEM, EDS mapping, water contact angle, and absorption time of solvent proved the successful grafting of alkyl chains on the CF without disturbing its special fiber structure, leading to the significantly enhanced hydrophobicity of the CF. The dynamic adsorption and elution behavior of kaempferol and quercetin (the typical flavonoid aglycones) on the hydrophobic CF showed that the adsorption rate and retention rate were largely increased in comparison with the CF without modification. Molecular dynamic simulations indicated that the CF grafted with isobutyls could interact with flavonoid aglycones through the highest synergetic effect of hydrophobic and hydrogen bond interactions, which exhibited the strongest retention to flavonoid aglycones. On further increasing the alkyl length (octyl and dodecyl), the hydrophobic interaction was further enhanced, but the hydrogen bonds were significantly weakened by steric hindrance, which showed that the retention to flavonoid aglycones was appropriately increased but without causing peak tailing. In the column separation of kaempferol and quercetin, the CF with hydrophobic modification presented a greater separation efficiency, with the purity of kaempferol increased from 71.99 to 86.57-97.50% and the purity of quercetin increased from 82.69 to 88.07-99.37%, which was much better than that of polyamide and close to that of sephadex LH 20. Therefore, the hydrophobicity of the CF could be controllably adjusted to enhance the adsorption rate and retention capacity, specifically improving the separation efficiency of flavonoid aglycones.


Subject(s)
Flavonoids , Quercetin , Flavonoids/chemistry , Kaempferols , Adsorption , Spectroscopy, Fourier Transform Infrared , Hydrophobic and Hydrophilic Interactions , Collagen/chemistry
11.
Biosensors (Basel) ; 13(2)2023 Feb 07.
Article in English | MEDLINE | ID: mdl-36831999

ABSTRACT

Carbon dots (CDs) are widely used in the detection of foodborne contaminants because of their biocompatibility, photoluminescence stability, and ease of chemical modification. In order to solve the interference problem of complexity in food matrices, the development of ratiometric fluorescence sensors shows great prospects. In this review, the progress of ratiometric fluorescence sensors based on CDs in foodborne contaminant detection in recent years will be summarized, focusing on the functionalized modification of CDs, the fluorescence sensing mechanism, the types of ratiometric fluorescence sensors, and the application of portable devices. In addition, the outlook on the development of the field will be presented, with the development of smartphone applications and related software helping to better enable the on-site detection of foodborne contaminants to ensure food safety and human health.


Subject(s)
Quantum Dots , Humans , Carbon , Fluorescence , Food Safety , Food , Fluorescent Dyes
12.
Phys Med Biol ; 68(5)2023 02 27.
Article in English | MEDLINE | ID: mdl-36731139

ABSTRACT

Objective. Irradiation at FLASH dose rates (>40 Gy s-1) has received great attention due to its reported normal tissue sparing effect. The FLASH effect was originally observed in electron irradiations but has since been shown to also occur with both photon and proton beams. Several mechanisms have been proposed to explain the tissue sparing at high dose rates, including effects involving oxygen, such as depletion of oxygen within the irradiated cells. In this study, we investigated the protective role of FLASH proton irradiation on the skin when varying the oxygen concentration.Approach. Our double scattering proton system provided a 1.2 × 1.6 cm2elliptical field at a dose rate of ∼130 Gy s-1. The conventional dose rate was ∼0.4 Gy s-1. The legs of the FVB/N mice were marked with two tattooed dots and fixed in a holder for exposure. To alter the skin oxygen concentration, the mice were breathing pure oxygen or had their legs tied to restrict blood flow. The distance between the two dots was measured to analyze skin contraction over time.Main results. FLASH irradiation mitigated skin contraction by 15% compared to conventional dose rate irradiation. The epidermis thickness and collagen deposition at 75 d following 25 to 30 Gy exposure suggested a long-term protective function in the skin from FLASH irradiation. Providing the mice with oxygen or reducing the skin oxygen concentration removed the dose-rate-dependent difference in response.Significance. FLASH proton irradiation decreased skin contraction, epidermis thickness and collagen deposition compared to standard dose rate irradiations. The observed oxygen-dependence of the FLASH effect is consistent with, but not conclusive of, fast oxygen depletion during the exposure.


Subject(s)
Proton Therapy , Protons , Mice , Animals , Proton Therapy/methods , Oxygen , Skin , Photons , Radiotherapy Dosage
13.
Cancer Med ; 12(8): 9175-9185, 2023 04.
Article in English | MEDLINE | ID: mdl-36708134

ABSTRACT

BACKGROUND: The role of induction chemotherapy (IC) in oropharyngeal squamous cell carcinoma (OPSCC) remains controversial. Its interpretation can be confounded by heterogeneity in chemosensitivity and human papillomavirus (HPV) status. This study aimed to investigate the prognostic impact of IC response in HPV-positive and -negative OPSCC. METHODS: Patients with OPSCC who underwent IC and concurrent chemoradiotherapy (CCRT) were retrospectively analyzed. Radiologic response to IC by ≥50% was defined as IC-sensitive (IC-s), while lesser response was deemed as IC-resistant (IC-r). Progression-free survival (PFS) and overall survival (OS) were compared between subgroups. RESULTS: A total of 51 HPV-positive and 57 HPV-negative patients were included. IC-s patients accounted for 55.6%, 62.7%, and 49.1% in the entire cohort, HPV-positive, and HPV-negative subgroup, respectively. Compared with IC-r subgroup, IC-s was associated with better clinical outcomes either in the entire cohort (3y-PFS 91.7%vs.43.7%, P < 0.001; 3y-OS 98.3% vs. 67.4%, P = 0.002), the HPV-positive subgroup (3-year PFS 94.7% vs. 47.9%, P < 0.001; 3-year OS 100% vs. 73.5%, P = 0.055) or the HPV-negative subgroup (3-year PFS 88.2% vs. 40.9%, P = 0.001; 3-year OS 96.4% vs. 63.1%, P = 0.026). Multivariate analysis demonstrated that response to IC represents an independent prognosticator for 3-year PFS (HR, 0.088; 95% CI, 0.027-0.289; P < 0.001) and 3-year OS (HR, 0.100; 95% CI, 0.021-0.477; P = 0.004). CONCLUSIONS: Response to IC exerts a critical predictive effect on prognosis of both HPV-positive and -negative OPSCC. Personalized treatment strategy based on IC response is worthy of further exploration in the future.


Subject(s)
Carcinoma, Squamous Cell , Head and Neck Neoplasms , Oropharyngeal Neoplasms , Papillomavirus Infections , Humans , Carcinoma, Squamous Cell/drug therapy , Induction Chemotherapy , Retrospective Studies , Oropharyngeal Neoplasms/drug therapy , Oropharyngeal Neoplasms/pathology , Squamous Cell Carcinoma of Head and Neck , Prognosis , Chemoradiotherapy , Head and Neck Neoplasms/complications
14.
World J Hepatol ; 15(12): 1294-1306, 2023 Dec 27.
Article in English | MEDLINE | ID: mdl-38223413

ABSTRACT

BACKGROUND: Liver cirrhosis (LC) is a prevalent and severe disease in China. The burden of LC is changing with widespread vaccination of hepatitis B virus (HBV) and antiviral therapy. However, the recent transition in etiologies and clinical features of LC cases requiring hospitalization is unclear. AIM: To identify the transition in etiologies and clinical characteristics of hospitalized LC patients in Southern China. METHODS: In this retrospective, cross-sectional study we included LC inpatients admitted between January 2001 and December 2020. Medical data indicating etiological diagnosis and LC complications, and demographic, laboratory, and imaging data were collected from our hospital-based dataset. The etiologies of LC were mainly determined according to the discharge diagnosis, and upper gastrointestinal bleeding, ascites, hepatic encephalopathy, spontaneous bacterial peritonitis, hepatocellular carcinoma (HCC), portal vein thrombosis, hepatorenal syndrome, and acute-on-chronic liver failure (ACLF) were considered LC-related complications in our study. Changing trends in the etiologies and clinical characteristics were investigated using logistic regression, and temporal trends in proportions of separated years were investigated using the Cochran-Armitage test. In-hospital prognosis and risk factors associated with in-hospital mortality were also investigated. RESULTS: A total of 33143 patients were included in the study [mean (SD) age, 51.7 (11.9) years], and 82.2% were males. The mean age of the study population increased from 51.0 years in 2001-2010 to 52.0 years in 2011-2020 (P < 0.001), and the proportion of female patients increased from 16.7% in 2001-2010 to 18.2% in 2011-2020 (P = 0.003). LC patients in the decompensated stage at diagnosis decreased from 68.1% in 2001-2010 to 64.6% in 2011-2020 (P < 0.001), and the median score of model for end-stage liver disease also decreased from 14.0 to 11.0 (P < 0.001). HBV remained the major etiology of LC (75.0%) and the dominant cause of viral hepatitis-LC (94.5%) during the study period. However, the proportion of HBV-LC decreased from 82.4% in 2001-2005 to 74.2% in 2016-2020, and the proportion of viral hepatitis-LC decreased from 85.2% in 2001-2005 to 78.1% in 2016-2020 (both P for trend < 0.001). Meanwhile, the proportions of LC caused by alcoholic liver disease, autoimmune hepatitis and mixed etiology increased by 2.5%, 0.8% and 4.5%, respectively (all P for trend < 0.001). In-hospital mortality was stable at 1.0% in 2011-2020, whereas HCC and ACLF manifested the highest increases in prevalence among all LC complications (35.8% to 41.0% and 5.7% to 12.4%, respectively) and were associated with 6-fold and 4-fold increased risks of mortality (odds ratios: 6.03 and 4.22, respectively). CONCLUSION: LC inpatients have experienced changes in age distribution and etiologies of cirrhosis over the last 20 years in Southern China. HCC and ACLF are associated with the highest risk of in-hospital mortality among LC complications.

15.
Proc Natl Acad Sci U S A ; 118(45)2021 11 09.
Article in English | MEDLINE | ID: mdl-34725151

ABSTRACT

Liver metastasis is a major cause of mortality for patients with colorectal cancer (CRC). Mismatch repair-proficient (pMMR) CRCs make up about 95% of metastatic CRCs, and are unresponsive to immune checkpoint blockade (ICB) therapy. Here we show that mouse models of orthotopic pMMR CRC liver metastasis accurately recapitulate the inefficacy of ICB therapy in patients, whereas the same pMMR CRC tumors are sensitive to ICB therapy when grown subcutaneously. To reveal local, nonmalignant components that determine CRC sensitivity to treatment, we compared the microenvironments of pMMR CRC cells grown as liver metastases and subcutaneous tumors. We found a paucity of both activated T cells and dendritic cells in ICB-treated orthotopic liver metastases, when compared with their subcutaneous tumor counterparts. Furthermore, treatment with Feline McDonough sarcoma (FMS)-like tyrosine kinase 3 ligand (Flt3L) plus ICB therapy increased dendritic cell infiltration into pMMR CRC liver metastases and improved mouse survival. Lastly, we show that human CRC liver metastases and microsatellite stable (MSS) primary CRC have a similar paucity of T cells and dendritic cells. These studies indicate that orthotopic tumor models, but not subcutaneous models, should be used to guide human clinical trials. Our findings also posit dendritic cells as antitumor components that can increase the efficacy of immunotherapies against pMMR CRC.


Subject(s)
Colorectal Neoplasms/drug therapy , Immune Checkpoint Inhibitors/therapeutic use , Liver Neoplasms, Experimental/drug therapy , Animals , Cell Line, Tumor , Colorectal Neoplasms/immunology , Colorectal Neoplasms/pathology , DNA Mismatch Repair , Dendritic Cells , Drug Screening Assays, Antitumor , Humans , Interferon-gamma/therapeutic use , Liver Neoplasms, Experimental/immunology , Liver Neoplasms, Experimental/secondary , Male , Mice, Inbred C57BL
16.
J Colloid Interface Sci ; 597: 393-400, 2021 Sep.
Article in English | MEDLINE | ID: mdl-33892422

ABSTRACT

Stretchable conductors are susceptible to wear through repeated deformation over time. Stretchable conductors with self-healing properties can increase longevity and reduce safety hazards. However, most current self-healing conductors can only repair either the conductive layer or the insulating layer. Meantime, high mechanical robustness and self-healing efficiency are exclusive especially at ambient conditions. Realizing a stretchable conductor with integral self-healing and ultra-high mechanical strength is challenging, because this requires good interfacial compatibility and adaptability of the conductive and insulating layers. We adapt a biphasic dynamic network strategy to add toughness to self-healing materials. The DOU (dimethylglyoxime-urethane polyurethane) dynamic bonds and hydrogen bonds in the soft phase enable high self-healing efficiency, while the graphene as a hard phase supports the material's superior mechanical properties. We have prepared an overall self-healing stretchable conductor through the soft phase as a self-encapsulating insulating layer. This all-solid (Tg = -49.5 °C) graphene/dimethylglyoxime-urethane polyurethane (Gr/DOU-PU) composites characteristic of both high mechanical strength (~6 MPa, ~1000%, ~48 MJ m-3), self-healing conductivity (~90%, 10 min, 25 °C) and conductivity (R□=47.8 Ω □-1, d = 0.4 mm). The conductor has excellent stability for flexible electronics and for building stress sensors.

17.
Radiat Res ; 194(6): 656-664, 2020 12 01.
Article in English | MEDLINE | ID: mdl-32991708

ABSTRACT

Extremely high-dose-rate irradiation, referred to as FLASH, has been shown to be less damaging to normal tissues than the same dose administrated at conventional dose rates. These results, typically seen at dose rates exceeding 40 Gy/s (or 2,400 Gy/min), have been widely reported in studies utilizing photon or electron radiation as well as in some proton radiation studies. Here, we report the development of a proton irradiation platform in a clinical proton facility and the dosimetry methods developed. The target is placed in the entry plateau region of a proton beam with a specifically designed double-scattering system. The energy after the double-scattering system is 227.5 MeV for protons that pass through only the first scatterer, and 225.5 MeV for those that also pass through the second scatterer. The double-scattering system was optimized to deliver a homogeneous dose distribution to a field size as large as possible while keeping the dose rate >100 Gy/s and not exceeding a cyclotron current of 300 nA. We were able to obtain a collimated pencil beam (1.6 × 1.2 cm2 ellipse) at a dose rate of ∼120 Gy/s. This beam was used for dose-response studies of partial abdominal irradiation of mice. First results indicate a potential tissue-sparing effect of FLASH.


Subject(s)
Proton Therapy/methods , Animals , Female , Mice , Mice, Inbred C57BL , Monte Carlo Method , Radiotherapy Dosage , Reproducibility of Results
18.
Gastroenterol Res Pract ; 2020: 8065972, 2020.
Article in English | MEDLINE | ID: mdl-32676106

ABSTRACT

BACKGROUND: Evaluation of lymph node status is critical in colorectal carcinoma (CRC) treatment. However, as patients with node involvement may be incorrectly classified into earlier stages if the examined lymph node (ELN) number is too small and escape adjuvant therapy, especially for stage II CRC. The aims of this study were to assess the impact of the ELN on the survival of patients with stage II colorectal cancer and to determine the optimal number. METHODS: Data from the US Surveillance, Epidemiology, and End Results (SEER) database on stage II resected CRC (1988-2013) were extracted for mathematical modeling as ELN was available since 1988. Relationship between ELN count and stage migration and disease-specific survival was analyzed by using multivariable models. The series of the mean positive LNs, odds ratios (ORs), and hazard ratios (HRs) were fitted with a LOWESS (Locally Weighted Scatterplot Smoothing) smoother, and the structural break points were determined by the Chow test. An independent cohort of cases from 2014 was retrieved for validation in 5-year disease-specific survival (DSS). RESULTS: An increased ELN count was associated with a higher possibility of metastasis LN detection (OR 1.010, CI 1.009-1.011, p < 0.001) and better DSS in LN negative patients (OR 0.976, CI 0.975-0.977, p < 0.001). The cut-off point analysis showed a threshold ELN count of 21 nodes (HR 0.692, CI 0.667-0.719, p < 0.001) and was validated with significantly better DSS in the SEER 2009 cohort CRC (OR 0.657, CI 0.522-0.827, p < 0.001). The cut-off value of the ELN count in site-specific surgeries was analyzed as 20 nodes in the right hemicolectomy (HR 0.674, CI 0.638-0.713, p < 0.001), 19 nodes in left hemicolectomy (HR 0.691, CI 0.639-0.749, p < 0.001), and 20 nodes in rectal resection patients (HR 0.671, CI 0.604-0.746, p < 0.001), respectively. CONCLUSIONS: A higher number of ELNs are associated with more-accurate node staging and better prognosis in stage II CRCs. We recommend that at least 21 lymph nodes be examined for accurate diagnosis of stage II colorectal cancer.

19.
PLoS One ; 15(5): e0232319, 2020.
Article in English | MEDLINE | ID: mdl-32369515

ABSTRACT

Aiming at the problem of fast certification for a constrained iris in the same category caused by the unstable iris features caused by the change of the iris acquisition environment and shooting status under lightweight training samples, a one-to-one fast certification algorithm for constrained unsteady-state iris based on the scale change stable feature and multi-algorithm voting is proposed. Scale change stable features are found by constructing an isometric differential Gaussian space, and a local binary pattern algorithm with extended statistics (ES-LBP), the Haar wavelet with over threshold detection and the Gabor filter algorithm with immune particle swarm optimization (IPSO) are used to represent the stable features as binary feature codes. Iris certification is performed by the Hamming distance. According to the certification results of three algorithms, the final result is obtained by multi-algorithm voting. Experiments with the JLU and CASIA iris libraries under the iris prerequisite conditions show that the correct recognition rate of this algorithm can reach a high level of 98% or more, indicating that this algorithm can improve the operation speed, accuracy and robustness of certification.


Subject(s)
Algorithms , Biometric Identification/methods , Iris , Pattern Recognition, Automated/methods , Humans , Image Processing, Computer-Assisted/methods
20.
RSC Adv ; 10(11): 6609-6617, 2020 Feb 07.
Article in English | MEDLINE | ID: mdl-35496022

ABSTRACT

Biofilm formation in the production of fermented vegetable might impact its quality and safety. In this study, physicochemical and microbial properties, volatile and aroma-active compounds between PRPs without biofilm (NPRP) and with biofilm (FPRP) were investigated by gas chromatography-mass spectrometry, gas chromatography-olfactometry, aroma extract dilution analysis, and spiking tests. The pH and titratable acidity were 3.66 ± 0.00 and 0.47 ± 0.08 g/100 g lactic acid in NPRP and 3.48 ± 0.01 and 0.87 ± 0.10 g/100 g lactic acid in FPRP, respectively. The nitrite level of the two PRPs was 1.87-1.92 mg kg-1, which was below the limited value (20 mg kg-1) of fermented vegetables regulated by the GB2760-2017. FPRP had relatively higher microbial and yeast numbers than NPRP, three common pathogens, namely, Salmonella spp., Staphylococcus aureus, and Shigella spp. were not detected. A total of 70 and 151 aroma compounds were detected in NPRP and FPRP, respectively, including 13 classes of compounds. The dominant aroma attributes of FPRP were sour, floral, mushroom-like, green, and smoky, while NPRP exhibits a mushroom-like flavor. Acetic acid, ethanol, α-terpineol, (E)-2-nonenal, 2-heptanol, phenylethyl alcohol, and linalool were potent key aroma-active compounds in NPRP and FPRP. Results of spiking tests showed that the addition of each substance not only increased its own odour, but also had significant effects on other smells. FPRP displayed richer varieties and contents of aroma profile than NPRP. However, some compounds, such as 4-ethylguaiacol and 4-vinylguaiacol, which were only detected in FPRP, had negative roles on the aroma attributes.

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