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1.
Behav Res Methods ; 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38689154

RESUMO

The ability to rapidly provide examinees with detailed and effective diagnostic information is a critical topic in psychology. Knowing what diagnostic criteria the examinees have met enables the practitioner to seek the solution to help them in a timely manner, and this can be achieved by cognitive diagnostic computerized adaptive testing (CD-CAT). However, the pervasive challenge of replenishing items in the CD-CAT item bank limits its practical application. Online calibration is a means to address item replenishment, but in CD-CAT, most existing online calibration methods that jointly calibrate the Q-matrix and item parameters of the new items are developed only for dichotomous responses and are time-consuming. Notably, previous studies pay no attention to polytomously scored items that are frequently observed in testing, even though they can offer additional evidence for the examinees' diagnosis. To fill this gap, we propose a SCAD-based method (SCAD-EM) to calibrate the Q-matrix and item parameters of the new items with polytomous response data in order to promote the application of CD-CAT in practice. The performance of the SCAD-EM was investigated in two comprehensive simulation studies and compared against the revised single-item estimation method (SIE-BIC). Results indicated that the SCAD-EM produces a higher calibration accuracy for the category-level Q-matrix and is computationally more efficient across all conditions, but it produces a lower calibration accuracy for the item-level Q-matrix. An empirical study further demonstrated the utility of the SCAD-EM and the SIE-BIC methods in calibrating new items with a real dataset. The advantages of the proposed method, its limitations, and possible future research directions are offered at the end.

2.
Chem Biol Drug Des ; 103(1): e14425, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38082476

RESUMO

The pneumonia outbreak caused by Severe Acute Respiratory Syndrome 2 (SARS-CoV-2) infection poses a serious threat to people worldwide. Although vaccines have been developed, antiviral drugs are still needed to combat SARS-CoV-2 infection due to the high mutability of the virus. SARS-CoV-2 main protein (Mpro ) is a special cysteine protease that is a key enzyme for SARS-CoV-2 replication. It is encoded by peptides and is responsible for processing peptides into functional proteins, making it an important drug target. The paper reviews the structure and peptide-like inhibitors of SARS-CoV-2 Mpro , also the binding mode and structure-activity relationship between the inhibitors and Mpro are introduced in detail. It is hoped that this review can provide ideas and help for the development of anti-coronavirus drugs such as COVID-19, and help to develop broad-spectrum antiviral drug for the treatment of coronavirus diseases as soon as possible.


Assuntos
COVID-19 , Proteases 3C de Coronavírus , Humanos , SARS-CoV-2/metabolismo , Proteínas não Estruturais Virais , Antivirais/farmacologia , Antivirais/uso terapêutico , Antivirais/química , Peptídeos/farmacologia , Inibidores de Proteases/metabolismo , Simulação de Acoplamento Molecular
3.
Open Life Sci ; 18(1): 20220476, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37588998

RESUMO

This study aimed to investigate whether α-fetoprotein (AFP) could affect the malignant behavior of AFP-producing gastric cancer (AFP-GC) and to explore the relationship between AFP and mesenchymal-epithelial transition factor (c-Met) in AFP-GC. In this study, 23 patients with AFP-GC (AFP[+]) and 18 patients with common gastric cancer (AFP[-]) were evaluated for the c-Met expression using immunohistochemical analysis. The AFP-GC cell line, GCIY, was used. The AFP endoribonuclease-prepared small interfering RNA (siRNA) and eukaryotic AFP overexpression vector were used to increase/knockdown the expression of AFP. Afterward, the c-Met expression was evaluated by polymerase chain reaction and western blot. The proliferation, migration, and invasion of GCIY cells were estimated before and after the AFP overexpression/knockdown. The c-Met expression in both groups was the same (p > 0.05), and AFP[+] group had a higher positive incidence of the c-Met expression than the AFP[-] group (p < 0.01). Furthermore, the c-Met expression frequency was decreased by AFP knockdown and increased by AFP overexpression (p < 0.01). The cell counting kit-8 cell proliferation assay, cell invasion, and migration assays confirmed that the AFP could affect the malignant biological behavior of AFP-GC. These findings suggest that AFP contributes to the malignant biological properties of AFP-GC and the high expression of c-Met in AFP-GC.

4.
Nat Prod Res ; : 1-7, 2023 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-37574795

RESUMO

Aimed to explore the mechanisms and targets of Diwu Yanggan Capsule (DWYG), a traditional Chinese medicine in liver regeneration, we used the TCMSP to obtain the active ingredients and targets of DWYG and the GEO database to obtain the DEGs related to liver regeneration. We also searched for liver regeneration-related genes in disease databases and integrated them with the herbal and GEO data to screen for potential targets of DWYG in liver regeneration. Enrichment analysis using R language and molecular docking of the key targets and active ingredients were constructed. We found 73 potential targets of DWYG in liver regeneration and revealed that DWYG may act through pathways such as MAPK, TNF, and IL-17. We also found that quercetin was a major component of DWYG with low binding energy to three key targets. Our results suggest that DWYG can facilitate liver regeneration and quercetin may be its core ingredient.

5.
Appl Radiat Isot ; 200: 110960, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37515858

RESUMO

The evaluation of radiation resistance of the treated radioactive contaminated soil is crucial. The irradiation behavior of simulated radioactive soil waste irradiated with 1.5 MeV Xe20+ ions at fluences of 1 × 1012-1 × 1015 ions/cm2 was studied. Before the irradiation experiment, all the samples were sintered by microwave. The results showed that microwave sintering may be used to treat radioactive contaminated soil. In addition, the irradiation experiment results show that when the Nd2O3 content was low (<20 wt.%), the irradiation has little effect on the sample. When the Nd2O3 content was higher, the Vickers hardness of the sample (25 wt.%) decreased by 7 % at a fluence of 1 × 1015 ions/cm2, which may be due to the high Nd2O3 content that destroyed the overall stability of the glass waste form. The low normalized leaching rate of the irradiated sample (LRNd, ∼10-6 g·m-2·d-1) also proved that it had good aqueous durability. Moreover, the radiation resistance of the sample was illustrated by studying the influence mechanism of 1.5 MeV Xe20+ irradiation on radioactive contaminated soil. This work can help to study the environmental pollution problems of radioactive contaminated soil containing various contents of actinide nuclear waste.

6.
Phytomedicine ; 116: 154893, 2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37236047

RESUMO

BACKGROUND: The liver is renowned for its remarkable regenerative capacity to restore its structure, size and function after various types of liver injury. However, in patients with end-stage liver disease, the regenerative capacity is inhibited and liver transplantation is the only option. Considering the limitations of liver transplantation, promoting liver regeneration is suggested as a new therapeutic strategy for liver disease. Traditional Chinese medicine (TCM) has a long history of preventing and treating various liver diseases, and some of them have been proven to be effective in promoting liver regeneration, suggesting the therapeutic potential in liver diseases. PURPOSE: This review aims to summarize the molecular mechanisms of liver regeneration and the pro-regenerative activity and mechanism of TCM formulas, extracts and active ingredients. METHODS: We conducted a systematic search in PubMed, Web of Science and the Cochrane Library databases using "TCM", "liver regeneration" or their synonyms as keywords, and classified and summarized the retrieved literature. The PRISMA guidelines were followed. RESULTS: Forty-one research articles met the themes of this review and previous critical studies were also reviewed to provide essential background information. Current evidences indicate that various TCM formulas, extracts and active ingredients have the effect on stimulating liver regeneration through modulating JAK/STAT, Hippo, PI3K/Akt and other signaling pathways. Besides, the mechanisms of liver regeneration, the limitation of existing studies and the application prospect of TCM to promote liver regeneration are also outlined and discussed in this review. CONCLUSION: This review supports TCM as new potential therapeutic options for promoting liver regeneration and repair of the failing liver, although extensive pharmacokinetic and toxicological studies, as well as elaborate clinical trials, are still needed to demonstrate safety and efficacy.


Assuntos
Medicamentos de Ervas Chinesas , Medicina Tradicional Chinesa , Humanos , Medicina Tradicional Chinesa/métodos , Medicamentos de Ervas Chinesas/química , Fosfatidilinositol 3-Quinases , Fitoterapia/métodos , Fígado
7.
Artigo em Inglês | MEDLINE | ID: mdl-36833682

RESUMO

The forest-landscape image is the bridge for communication between human beings and the forest. The aim of this paper is to construct the landscape-image conceptual model from the personal perception of the forest, with what people are looking at and how they are viewing themselves as a part of the forest. This research constructed a forest-landscape image by young adults by utilizing the landscape-image-sketching technique and selecting 140 young adults who had lived in Changsha, Central China for ten years, using convenience sampling, during April and May 2018. The results demonstrated that the forest was considered as the people's life world, as rural scenery around the respondents' homes, instead of the perception of the objective forest, an important habitat for animals and a limited resource supplier for human living. In fact, the natural values of the forest, such as the ecological and aesthetic values, received more attention than the social ones of the forest, including the life, production, and cultural values. Finally, it is important to raise the public's awareness of the objective entity of the forest and to guide the variety of experiences for the respondents in the forest.


Assuntos
Ecossistema , Florestas , Humanos , Adulto Jovem , Animais , Estética , Comunicação , Percepção , China , Conservação dos Recursos Naturais
9.
Br J Math Stat Psychol ; 76(2): 283-311, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36289154

RESUMO

Computerized adaptive testing for cognitive diagnosis (CD-CAT) needs to be efficient and responsive in real time to meet practical applications' requirements. For high-dimensional data, the number of categories to be recognized in a test grows exponentially as the number of attributes increases, which can easily cause system reaction time to be too long such that it adversely affects the examinees and thus seriously impacts the measurement efficiency. More importantly, the long-time CPU operations and memory usage of item selection in CD-CAT due to intensive computation are impractical and cannot wholly meet practice needs. This paper proposed two new efficient selection strategies (HIA and CEL) for high-dimensional CD-CAT to address this issue by incorporating the max-marginals from the maximum a posteriori query and integrating the ensemble learning approach into the previous efficient selection methods, respectively. The performance of the proposed selection method was compared with the conventional selection method using simulated and real item pools. The results showed that the proposed methods could significantly improve the measurement efficiency with about 1/2-1/200 of the conventional methods' computation time while retaining similar measurement accuracy. With increasing number of attributes and size of the item pool, the computation time advantage of the proposed methods becomes more significant.


Assuntos
Avaliação Educacional , Aprendizado de Máquina , Avaliação Educacional/métodos
10.
J Environ Manage ; 324: 116342, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36166870

RESUMO

In order to find a rapid, efficient, safe and reliable treatment technology for radioactive contaminated soil, the microwave sintering method was used to sinter the simulated radioactive contaminated soil with different CeO2 content at 1100 °C, 1200 °C and 1300 °C for 30 min to achieve vitrification. The phase, microstructure, morphology, mechanical properties, and chemical durability of the sintered samples were investigated. XRD and SEM-EDS results showed that Ce4+ did not participate in the formation of the glass network, but was fixed in the glass network structure. The amorphous fraction of the samples sintered at 1300 °C can reach up to 98%. EDS results showed that the element distribution was uniform. In addition, the density and hardness values of the sintered matrices were in the range of 1.875-2.543 g/cm3 and 6.667-7.112 GPa, respectively. Our results show that the density and hardness values are related to the sintering temperature and CeO2 content. The normalized leaching rate of Ce in samples reached 10-7 g/(m2·d) after 28 d.


Assuntos
Vidro , Micro-Ondas , Temperatura , Teste de Materiais , Solo
11.
Front Pharmacol ; 13: 807330, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35185566

RESUMO

As a nonspecific antagonist of the adenosine A2A receptor (A2AR), caffeine enhances learning and improves memory impairment. Simultaneously, the consumption of caffeine correlates with a feeling of anxiety. The hippocampus is functionally differentiated along its dorsal/ventral axis and plays a crucial role both in memory and anxiety. Whether caffeine exerts its regulation by inhibiting A2ARs in different subregions of the hippocampus is still unknown. In the present study, we found that after chronic intake of drinking water containing caffeine (1 g/L, 3 weeks), mice exhibited aggravated anxiety-like behavior and enhanced memory function. Tissue-specific, functional disruption of dorsal hippocampal A2ARs by the CRE-LoxP system prevented the memory-enhancing effect of caffeine, while selective disruption of ventral hippocampal A2ARs blocked the impact of caffeine on anxiety. These results, together with the enhanced memory of dorsal hippocampus A2AR knockout mice and greater anxiety-like behavior of ventral hippocampus A2AR knockout mice without caffeine, indicates a dissociation between the roles of ventral and dorsal hippocampal A2A receptors in caffeine's effects on anxiety-like and memory-related behavioral measures, respectively. Furthermore, optogenetic activation of dorsal or ventral hippocampal A2ARs reversed the behavioral alterations caused by drinking caffeine, leading to impaired memory or decreased anxiety-like behaviors, respectively. Taken together, our findings suggest that the memory- and anxiety-enhancing effects of caffeine are related to the differential effects of inhibiting A2ARs in the dorsal and ventral hippocampus, respectively.

12.
Oncol Lett ; 23(3): 84, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35126726

RESUMO

High serum alpha-fetoprotein (AFP) level is a predictor of poor prognosis in patients with gastric cancer (GC). AFP-producing GC (AFP-GC) is an aggressive subtype of GC characterized by a high incidence of liver metastasis and high c-Met expression. High expression of metastasis-associated colon cancer 1 (MACC1), which is the transcription activator of c-Met, also predicts a poor prognosis of GC. c-Met is known to be involved in tumor progression into malignant invasive phenotypes. Considering that high c-Met expression is simultaneously positively correlated with high AFP and MACC1 expression levels and that high expression of AFP or MACC1 predicts poor prognosis in GC, we hypothesized that an interaction may exist between AFP and MACC1. In the present study, GC cell lines with AFP-overexpression, MACC1-downregulation and the combination of both transfections were used as experimental models. The relative mRNA and protein expression of c-Met, AFP and MACC1 were analyzed using reverse transcription quantitative PCR and western blotting, respectively. Cell viability was evaluated using Cell Counting Kit-8 assay. Cell invasion and cell migration were examined using Transwell migration assay with and without Matrigel, respectively. The results demonstrated that, compared with the control group, the mRNA and protein expression of MACC1was significantly elevated in the AFP-overexpressed group and in the group with AFP overexpressed and MACC1 downregulated. Furthermore, a significantly enhanced cell viability, migration and invasion were observed in the AFP-overexpressing group, whereas opposite effects were found in the MACC1-downregulating group. In summary, the results from this study indicated that AFP may promote GC progression by stimulating MACC1. This finding may help illustrating the aggressive behaviors of GC in patients with high AFP serum level and AFP-GC.

13.
Multivariate Behav Res ; 57(6): 940-959, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34152873

RESUMO

To advance the theoretical foundation of incorporating response times (RTs) into diagnostic classification models (DCMs), this study attempts to further derive, test and illustrate a generalized modeling framework (known as the JVRT-LCDM) that can simultaneously analyze response accuracy and differential speediness based on an existing method (Zhan et al., British Journal of Mathematical and Statistical Psychology, 71(2), 262-286, 2018). The JVRT-LCDM not only provides fine-grained diagnostic feedback without strict model constraints but also clarifies the specific speed trajectory of individuals. Moreover, some existing models from psychometric literatures are included in the JVRT-LCDM as special cases. The feasibility of the JVRT-LCDM is investigated via a Monte Carlo simulation study using a Bayesian estimation scheme, and two empirical datasets are then analyzed to illustrate the applicability of the JVRT-LCDM in practice. The results indicate that (1) as a generalized and flexible model, the JVRT-LCDM realizes high correct classification rates and accurate speed parameter recovery; (2) the JVRT-LCDM outperforms the existing models in terms of model-data fit, diagnostic consistency, and estimation of specific individuals in practical cognitive diagnosis assessments; and (3) the JVRT-LCDM provides reliable evidence for nonconstant speed modeling.


Assuntos
Avaliação Educacional , Humanos , Teorema de Bayes , Método de Monte Carlo , Simulação por Computador , Psicometria/métodos
14.
Front Neurorobot ; 16: 1065099, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36714153

RESUMO

Finger-vein biometrics has been extensively investigated for personal verification. Single sample per person (SSPP) finger-vein recognition is one of the open issues in finger-vein recognition. Despite recent advances in deep neural networks for finger-vein recognition, current approaches depend on a large number of training data. However, they lack the robustness of extracting robust and discriminative finger-vein features from a single training image sample. A deep ensemble learning method is proposed to solve the SSPP finger-vein recognition in this article. In the proposed method, multiple feature maps were generated from an input finger-vein image, based on various independent deep learning-based classifiers. A shared learning scheme is investigated among classifiers to improve their feature representation captivity. The learning speed of weak classifiers is also adjusted to achieve the simultaneously best performance. A deep learning model is proposed by an ensemble of all these adjusted classifiers. The proposed method is tested with two public finger vein databases. The result shows that the proposed approach has a distinct advantage over all the other tested popular solutions for the SSPP problem.

15.
J Cell Mol Med ; 25(19): 9112-9127, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34427967

RESUMO

Gastric cancer (GC) serves as a common malignancy. Long non-coding RNAs (lncRNAs) have been proven to regulate many cancers, including GC. Long intergenic non-protein-coding RNA 511 (LINC00511) has been poorly studied in GC, but its detailed regulatory mechanism has not been identified. Here, LINC00511 was detected to be highly expressed in GC cells. Functional assays were conducted and uncovered that LINC00511 boosted cell proliferation, migration, stemness and EMT process while inhibiting the apoptosis of GC cells. From a series of mechanism experiments, it was found that at the transcriptional level, LINC00511 recruited EZH2 (enhancer of zeste 2 polycomb repressive complex 2 subunit) to the promoter of PTEN (phosphatase and tensin homolog) and facilitated methylation of PTEN promoter. LINC00511 epigenetically repressed PTEN to activate the PI3K/AKT pathway. Moreover, SRY-box transcription factor 4 (SOX4) activated the transcription of LINC00511. At the post-transcriptional level, LINC00511 sponged miR-195-5p to elevate SOX4 expression in GC cells. On the whole, the present study disclosed that SOX4-induced LINC00511 activated SOX4 via competing endogenous RNA (ceRNA) pattern and epigenetically repressed PTEN to activate PI3K/AKT pathway by recruiting EZH2, thus facilitating GC cell proliferation, migration and stemness while inhibiting GC cell apoptosis.


Assuntos
Regulação Neoplásica da Expressão Gênica , PTEN Fosfo-Hidrolase/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Longo não Codificante/genética , Fatores de Transcrição SOXC/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Progressão da Doença , Transição Epitelial-Mesenquimal/genética , Imunofluorescência , Xenoenxertos , Humanos , Masculino , Camundongos , Oncogenes , Regiões Promotoras Genéticas , Neoplasias Gástricas/patologia
16.
J Orthop Surg Res ; 16(1): 299, 2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-33962632

RESUMO

OBJECTIVE: To analyze the effect of sacrificing the posterior cruciate ligament (PCL) on the early postoperative outcome of cruciate retaining (CR) highly congruent rotating platform TKA. METHODS: From May 2018 to September 2019, 105 cases of total knee arthroplasty (TKA) with CR highly congruent rotating platform prosthesis were retrospectively analyzed. According to the tension of posterior cruciate ligament, they were divided into sacrifice group (29 cases, 27.6%) and retention group (76 cases, 72.4%). Preoperative and postoperative The Hospital for Special Surgery (HSS) score, range of motion (ROM) were compared between the two groups. In addition, postoperative infection, prosthesis loosening, bearing dislocation, and other complications were also compared. RESULTS: All patients were followed up for 11~24 months (mean 18.14 ± 3.52) months. There was no significant difference in general data, preoperative HSS score, and ROM between the two groups (P > 0.05). At the last follow-up, HSS score and ROM of the two groups were better than those before operation (P < 0.05). However, there was no significant difference between the two groups (P > 0.05). Moreover, there were no complications such as infection, loosening of prosthesis, and bearing dislocation in all cases. CONCLUSION: In CR, highly congruent rotating platform TKA with or without tension of the PCL can achieve satisfactory outcomes. Tension-free PCL do not cause joint instability.


Assuntos
Artroplastia do Joelho/métodos , Prótese do Joelho , Osteoartrite do Joelho/cirurgia , Ligamento Cruzado Posterior/cirurgia , Desenho de Prótese , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/fisiopatologia , Amplitude de Movimento Articular , Estudos Retrospectivos , Resultado do Tratamento
17.
J Card Surg ; 36(8): 2714-2721, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34018259

RESUMO

PURPOSE: Clinical treatment of gastrointestinal neoplasms in patients with severe coronary stenosis is difficult, and it remains controversial to perform staged or simultaneous surgeries. The purpose of this study was to retrospectively analyze the feasibility and indications for simultaneous gastrointestinal tumor resection and off-pump coronary artery bypass (OPCAB) graft surgery. METHODS: Data collected from a total of five patients, including three patients with gastric cancer and two patients with colorectal cancer, who underwent simultaneous radical cancer resection and OPCAB between September 2010 and October 2019, were retrospectively analyzed. Among these patients, one had an incomplete colonic obstruction. All patients had severe coronary stenosis, and one experienced acute heart failure before surgery. OPCAB was performed first, followed by the radical cancer resection. RESULTS: All five patients were discharged from hospital without perioperative death, major cardiovascular events or anastomotic leakage. The mean postoperative hospital stay was 9.4 days. One patient experienced slight gastrointestinal bleeding after surgery, which improved with conservative treatment. After a mean follow-up of 39 months, two patients with gastric cancer died from tumor metastasis at 28 months and 37 months, while the remaining three patients did not have tumor recurrence or metastasis. None of the patients experienced myocardial ischemia. CONCLUSION: It is safe and feasible to perform simultaneous OPCAB and gastrointestinal surgeries on the premise of strictly controlling the indications for patients with gastrointestinal tumors complicated with severe coronary artery stenosis.


Assuntos
Ponte de Artéria Coronária sem Circulação Extracorpórea , Neoplasias Gastrointestinais , Estudos de Viabilidade , Humanos , Recidiva Local de Neoplasia , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Resultado do Tratamento
18.
Gastroenterol Res Pract ; 2021: 6610737, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33574839

RESUMO

We propose a modification to the reconstruction method of natural orifice specimen extraction surgery (NOSES) during laparoscopic anterior resection (LAR) for rectal cancer (RC) and evaluated its feasibility and short-term safety by comparing surgical and postoperative outcomes with those of conventional LAR. Twenty patients with RC underwent "double-purse" NOSES-LAR from October 2017 to June 2018. Data of clinicopathological characteristics, surgical and postoperative outcomes, and follow-up findings in NOSES-LAR cases were collected and retrospectively compared with those of conventional LAR to clarify the clinical benefits. The median postoperative hospital stay was lower in the double-purse NOSES group than the conventional group (6.6 vs. 7.1 days, respectively). In the conventional group, anastomotic leakage and incision site infection occurred in one patient each. In contrast, there were no complications in the double-purse group. There were no significant differences in blood loss, surgical duration, and time of the first flatus between the two groups. Additionally, "double-purse" NOSES-LAR was more economical than the conventional LAR. "Double-purse" NOSES-LAR is a safe, feasible, and minimally invasive promising procedure for LAR of RC with faster recovery, while requiring less surgical skills and lower clinical costs.

19.
J Hazard Mater ; 407: 124761, 2021 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-33316687

RESUMO

Consecutive microwave sintering is a method proposed in this study to dispose soil contaminated by Sr during a nuclear accident by rapidly solidifying the contaminated soil. The results show that soil contaminated with 20 wt% SrSO4 and 30 wt% SrSO4 can be completely solidified by microwave sintering at 1100-1200 and 1300 â„ƒ, respectively, for 30 min. Sr was found to be cured into slawsonite (SrAl2Si2O8) and glass structures. Moreover, soil sintered at 1300 â„ƒ has large cured solubility (30 wt.%), good uniformity, and excellent hardness (6.9-7.2 GPa) and chemical durability (below 1.46 × 10-5 g m-2 d-1 at 28 d). Thus, consecutive microwave sintering technology may provide a new method for treating Sr-contaminated soil in case of a nuclear accident emergency.

20.
J Hazard Mater ; 405: 124273, 2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33131939

RESUMO

In the field of radioactive waste immobilization, the investigation of irradiation stability is of considerable importance. In this study, uranium-contaminated soil samples were irradiated by 1.5 MeV Xe20+ ions with fluences ranging from 1 × 1012 to 1 × 1015 ions/cm2. Xe20+ heavy-ion radiation was used to simulate the self-irradiation of actinide nuclides. The uranium-contaminated soil samples were sintered via microwaves. Grazing incidence X-ray diffraction results showed that irradiation can cause crystallization of the sample. After irradiation, the Vickers hardness of the samples decreased slightly. Comparative analysis showed that the sample had good radiation resistance, and the leaching rate (28 d) of the sample increased slightly after irradiation, but the overall performance was stable. Our investigation reveals the corresponding mechanism of uranium-contaminated soil irradiation of 1.5 MeV Xe20+ ions.

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