Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
1.
Sensors (Basel) ; 24(11)2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38894073

RESUMO

This article presents a hierarchical control framework for autonomous vehicle trajectory planning and tracking, addressing the challenge of accurately following high-speed, at-limit maneuvers. The proposed time-optimal trajectory planning and tracking (TOTPT) framework utilizes a hierarchical control structure, with an offline trajectory optimization (TRO) module and an online nonlinear model predictive control (NMPC) module. The TRO layer generates minimum-lap-time trajectories using a direct collocation method, which optimizes the vehicle's path, velocity, and control inputs to achieve the fastest possible lap time, while respecting the vehicle dynamics and track constraints. The NMPC layer is responsible for precisely tracking the reference trajectories generated by the TRO in real time. The NMPC also incorporates a preview algorithm that utilizes the predicted future travel distance to estimate the optimal reference speed and curvature for the next time step, thereby improving the overall tracking performance. Simulation results on the Catalunya circuit demonstrated the framework's capability to accurately follow the time-optimal raceline at an average speed of 116 km/h, with a maximum lateral error of 0.32 m. The NMPC module uses an acados solver with a real-time iteration (RTI) scheme, to achieve a millisecond-level computation time, making it possible to implement it in real time in autonomous vehicles.

2.
BMC Nurs ; 23(1): 436, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38926673

RESUMO

OBJECTIVE: This study aimed to analyze and explore the nursing effects of integrated medical and nursing care intervention in correction surgery for children with concealed penis. METHODS: A total of 76 eligible patients with concealed penis were randomly divided into an observation group and a control group. The control group received conventional nursing care, while the observation group received integrated medical and nursing care intervention. Outcomes include pain levels, comfort status, incidence of complications, and nursing satisfaction were collected and analyzed to investigate the nursing effects of the integrated medical and nursing care model. RESULTS: After 2/3 days of nursing intervention, the patients in the observation group had significantly lower pain scores (measured by FPS-R) compared to the control group (P < 0.05). The patients in the observation group also had significantly higher comfort scores (measured by Kolcabal) compared to the control group (P < 0.05). The incidence of complications in the observation group was significantly lower than that in the control group (2.63 vs. 23.68, P < 0.05). Parental satisfaction in the observation group was significantly higher than that in the control group (P < 0.05). CONCLUSION: The integrated medical and nursing care intervention in correction surgery for children with concealed penis demonstrated positive nursing effects. It effectively reduced pain, improved comfort, lowered the risk of complications, and increased parental satisfaction. This approach maximizes the role of nursing care and is recommended for clinical implementation.

3.
J Neurooncol ; 163(2): 429-437, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37222918

RESUMO

OBJECTIVE: To compare the clinical outcomes of large or giant vestibular schwannomas (VSs) between older patients and younger patients who underwent microsurgery and to explore whether the incidence of postoperative complications increased and whether the postoperative hospital stay was prolonged. METHODS: We conducted a retrospective matched cohort study based on the surgical approach, maximum tumor diameter and extent of resection. Older patients (≥ 60 years) and a matched group (<60 years) who had undergone microsurgery for VSs between January 2015 and December 2021 were included. Clinical data, surgical outcomes and postoperative complications were analyzed statistically. RESULTS: Forty-two older patients (≥ 60 years, 66.0 ± 3.8 years) were identified and matched to younger patients (<60 years, 43.9 ± 11.2 years), and they all underwent microsurgery through a retrosigmoid approach. There were twenty-nine patients with 3-4 cm VSs and thirteen patients with > 4 cm VSs in both groups. The older patients had a higher proportion of imbalance (P = 0.016) and lower American Society of Anesthesiology scores (P = 0.003) before surgery than the younger patients. There was no significant difference in facial nerve function one week (p = 0.851) and one year (p = 0.756) after surgery and no difference in the postoperative complication incidence (40.5% vs. 23.8%, p = 0.102) between the older patients and controls. Furthermore, the older patients had longer postoperative hospital stays than the younger patients (p = 0.043). In the older group, six patients with near total resection and five with subtotal resection were administered stereotactic radiotherapy, and one had recurrence three years after surgery and received conservative treatment. The postoperative follow-up time ranged from 1 to 83 months, with an average of 33.5 ± 21.1 months. CONCLUSIONS: For older patients (≥ 60 years) with symptomatic, large or giant -VSs, microsurgery is the only effective method to prolong lifespan, alleviate clinical symptoms and cure the tumor. However, radical resection of VSs may result in a decreased preservation rate of facial-acoustic nerve function and an increased postoperative complication incidence. Therefore, subtotal resection followed by stereotactic radiotherapy should be recommended.


Assuntos
Neuroma Acústico , Radiocirurgia , Humanos , Idoso , Estudos de Coortes , Estudos Retrospectivos , Microcirurgia/efeitos adversos , Microcirurgia/métodos , Resultado do Tratamento , Neuroma Acústico/patologia , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Radiocirurgia/efeitos adversos , Nervo Facial/patologia
4.
Neurosurg Rev ; 46(1): 224, 2023 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-37665381

RESUMO

The incidence of unplanned reoperation after surgery during the same hospitalization is considered one of most important evaluation indicators for health care quality. The purpose of this study was to determine the incidence and risk factors related to unplanned reoperation after an endoscopic endonasal approach (EEA). All patients who underwent elective endoscopic endonasal surgery from January 2016 to December 2021 in the Department of Neurosurgery, Tangdu Hospital, Air Force Military Medical University, were included. We identified the patients who underwent an unplanned reoperation and those who did not and divided them into two groups. The demographic data and risk factors were compared between the groups by univariate and multivariate logistic regression analyses. Of the 1783 patients undergoing EEA for various lesions of the skull base, the incidence of unplanned reoperation was 2.3%. The most common unplanned reoperations were repair of cerebrospinal fluid (CSF) leakage (39%), sellar hematoma evacuation (34.1%), hemostasis of epistaxis (14.6%) and external ventricular drainage for obstructive hydrocephalus (9.8%). The maximum diameter of tumor ≥ 3 cm (OR 2.654, CI 1.236-5.698; p = 0.012), meningioma (OR 4.198, CI 1.169-15.072; p = 0.028), craniopharyngioma (OR 5.020, CI 2.020-12.476; p = 0.001) and other sellar lesions (OR 4.336, CI 1.390-13.527; p = 0.012) and an operation time ≥ 240 min (OR 2.299, CI 1.170-4.518; p = 0.016) were the independent risk factors for unplanned reoperations in multivariate regression analysis. Of the 41 patients undergoing unplanned reoperation, 16 patients died, twenty-one patients had panhypopituitarism, 13 patients had transient and 6 had permanent diabetes insipidus, and 11 patients presented with intracranial infection and 6 of these patients were cured. By reviewing our department's data, we stated the incidence and risk factors for unplanned reoperation. It is important for the hospital administration and neurosurgeons to place more emphasis on these indicators. Furthermore, we suggest some effective quality improvement initiatives to reduce the incidence of unplanned reoperation.


Assuntos
Neoplasias Meníngeas , Neoplasias Hipofisárias , Humanos , Reoperação , Incidência , Endoscopia , Vazamento de Líquido Cefalorraquidiano/epidemiologia , Vazamento de Líquido Cefalorraquidiano/cirurgia , Neoplasias Hipofisárias/cirurgia
5.
Zhongguo Yi Liao Qi Xie Za Zhi ; 47(5): 582-586, 2023 Sep 30.
Artigo em Chinês | MEDLINE | ID: mdl-37753902

RESUMO

In recent years, with the rapid development of Chinese domestic surgical robot technology and the expansion of the application market, the "industry-university-research-medicine" collaborative innovation transformation mode has gradually developed and formed. Medical institutions play an important role in multi-party cooperation with enterprises, universities, and research institutes, as well as in product planning, technology research and development, achievement transformation, and personnel training. On the basis of reviewing the current situation of the development of the "industry-university-research-medicine" collaborative innovation transformation mode of domestic surgical robots, this study explores the multiple roles played by medical institutions in this mode and challenges, further putting forward corresponding recommendations.


Assuntos
Medicina , Robótica , Humanos , Universidades , Indústrias , Tecnologia
6.
J Transl Med ; 19(1): 415, 2021 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-34620163

RESUMO

BACKGROUND: Immune checkpoint blockades (ICBs) therapy showed limited efficacy in ovarian cancer management. Increasing evidence indicated that conventional and targeted therapies could affect tumor-associated immune responses and increase the effectiveness of immunotherapy. However, the effects of Niraparib, one of the poly (ADP) ribose polymerase (PARP) inhibitors, on the immune response remains unclear. Delineating the crosstalk between cytotoxic anticancer agents and cancer-associated immunity may lead to more efficient combinatorial strategies. METHODS: Programmed death ligand 1 (PD-L1) expression in human ovarian cancer cells after PARP inhibitors treatment was examined by western blotting (WB) and flow cytometry. The expression of poly ADP-ribose polymerase (PARP1), PD-L1, and CD8 in human ovarian cancer tissues was detected by immunohistochemistry(IHC). The effect of Niraparib and PD-L1 blockade in ovarian cancer progression was investigated in vivo. The changes of immune cells and cytokines in vitro and in vivo were detected by flow cytometry and enzyme-linked immunosorbent assay (ELISA). Changes of cGAS/STING signal pathway after Niraparib treatment were determined by WB, ELISA. RESULTS: Niraparib upregulated membrane PD-L1 and total PD-L1 expression in ovarian cancer cells and had a synergistic effect with PD-L1 blockade in vivo. In clinical patient samples, Niraparib augmented cytotoxic CD8+T cell proportion and function. In vivo and vitro, Niraparib can also increase the proportion of T cells and combined with PD-L1 blockade could further enhance the effect. Besides, Niraparib activated the cGAS-STING pathway, increasing the levels of cytokines such as CCL5 and CXCL10, which played a vital role in augmenting the infiltration and activation of cytotoxic T cells. CONCLUSIONS: Niraparib could modulate the immune response via the activation of the cGAS/STING pathway, and combination with PD-L1 blockade could further enhance the effect. These results provide a sound theoretical basis for clinical treatment.


Assuntos
Antígeno B7-H1 , Neoplasias Ovarianas , Feminino , Humanos , Imunidade , Indazóis/farmacologia , Indazóis/uso terapêutico , Neoplasias Ovarianas/tratamento farmacológico , Piperidinas
7.
Acta Obstet Gynecol Scand ; 100(10): 1771-1778, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34027996

RESUMO

Ovarian granulosa cell tumor (GCT) is a rare, low-grade malignant tumor that accounts for 70% of the sex cord-stromal tumors. It has two histopathologic types with different clinical and biologic features: adult GCT and juvenile GCT. Most women diagnosed with the adult GCT have a favorable prognosis, with a 5-year survival rate of 97%-98%, but adult GCT has a feature of late relapse; the recurrence time could be more than 20 years after diagnosis. Juvenile GCT has a survival rate of 97% in stage I and a 5-year survival rate of 0%-22% in advanced stage with earlier recurrence than adult GCT. Consequently, the scenario emphasizes the need for early diagnosis, standardized treatment protocols, and long-term follow up. However, there is a lack of consensus regarding accurate diagnosis of GCT and adjuvant treatment. Furthermore, GCT tends to occur in young women, which emphasizes the viability of fertility-sparing surgery. The current review performed a systematic literature review of 60 articles to summarize the latest advances in GCT, with an emphasis on the molecular pathogenesis and survival after fertility-sparing surgery. We found that young women with fertility-sparing surgery had a desirable reproductive and survival outcome compared with those undergoing radical surgery.


Assuntos
Preservação da Fertilidade , Tumor de Células da Granulosa/cirurgia , Recidiva Local de Neoplasia/cirurgia , Neoplasias Ovarianas/cirurgia , Feminino , Tumor de Células da Granulosa/mortalidade , Humanos , Recidiva Local de Neoplasia/mortalidade , Neoplasias Ovarianas/mortalidade , Análise de Sobrevida
9.
Opt Lett ; 41(14): 3317-9, 2016 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-27420524

RESUMO

Composite YAG/15 at. % Yb:LuAG/YAG transparent ceramic planar waveguide was fabricated by a tape casting method and vacuum sintering technology. Under a 970 nm diode laser pumping, the absorbed efficiency of 85.4% was achieved, and efficient CW laser operation at 1030.7 nm was accomplished with a good beam quality with Gaussian spatial profile. A maximum output power of 288 mW was obtained under a pump power of 4.69 W, corresponding to a slope efficiency of 9% and an O-O conversion efficiency of 5%.

10.
Sensors (Basel) ; 16(6)2016 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-27304956

RESUMO

We developed a new method for detecting S1 nuclease and hydroxyl radicals based on the use of water-soluble conjugated poly[9,9-bis(6,6-(N,N,N-trimethylammonium)-fluorene)-2,7-ylenevinylene-co-alt-2,5-dicyano-1,4-phenylene)] (PFVCN) and tungsten disulfide (WS2) nanosheets. Cationic PFVCN is used as a signal reporter, and single-layer WS2 is used as a quencher with a negatively charged surface. The ssDNA forms complexes with PFVCN due to much stronger electrostatic interactions between cationic PFVCN and anionic ssDNA, whereas PFVCN emits yellow fluorescence. When ssDNA is hydrolyzed by S1 nuclease or hydroxyl radicals into small fragments, the interactions between the fragmented DNA and PFVCN become weaker, resulting in PFVCN being adsorbed on the surface of WS2 and the fluorescence being quenched through fluorescence resonance energy transfer. The new method based on PFVCN and WS2 can sense S1 nuclease with a low detection limit of 5 × 10(-6) U/mL. Additionally, this method is cost-effective by using affordable WS2 as an energy acceptor without the need for dye-labeled ssDNA. Furthermore, the method provides a new platform for the nuclease assay and reactive oxygen species, and provides promising applications for drug screening.


Assuntos
Técnicas Biossensoriais/métodos , Endonucleases/isolamento & purificação , Radical Hidroxila/isolamento & purificação , Nanoestruturas/química , DNA de Cadeia Simples/química , Endonucleases/química , Fluorenos/química , Transferência Ressonante de Energia de Fluorescência , Radical Hidroxila/química , Limite de Detecção , Polímeros/química , Espécies Reativas de Oxigênio/química , Compostos de Tungstênio/química , Água/química
11.
Analyst ; 140(13): 4642-7, 2015 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-25978496

RESUMO

In this paper, we described a new DNAzyme-based fluorescent biosensor for the detection of Pb(2+). In the biosensor, the bulged structure is formed between the substrate labeled with fluorescein amidite (FAM) and DNAzyme after being annealed. Ethidium bromide (EB), the DNA intercalator, then intercalates into the double-stranded DNA section. Once FAM is excited, the FRET takes place from FAM to EB, which leads to the fluorescence of FAM decreasing greatly. In the presence of Pb(2+), the substrate is cleaved by DNAzyme, which breaks the bulged structure. Then EB is released and the FRET from FAM to EB is inhibited. In this case, the fluorescence of FAM increases dramatically. Thus, the Pb(2+) ions can be detected by measuring the fluorescence enhancement of FAM. Under optimal conditions, the increased fluorescence intensity ratio of FAM is dependent on the lead level in the sample, and exhibits a linear response over a Pb(2+) concentration range of 0-100 nM with a detection limit of 530 pM. The sensor showed high selectivity in the presence of a number of interference ions. The river water samples were also tested with satisfying results by using the new method. This sensor is highly sensitive and simple without any additional treatments, which provides a platform for other biosensors based on DNAzyme.


Assuntos
Técnicas Biossensoriais/métodos , DNA Catalítico/metabolismo , Poluentes Ambientais/análise , Chumbo/análise , Limite de Detecção , Sequência de Bases , DNA Catalítico/química , DNA Catalítico/genética , Etídio/química , Fluoresceína/química , Espectrometria de Fluorescência , Fatores de Tempo
12.
Int Urol Nephrol ; 56(6): 1795-1801, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38305938

RESUMO

OBJECTIVE: To evaluate the efficacy of different dressing methods in wound healing and the postoperative outcome in children who underwent hypospadias repair. METHODS: Altogether 109 children with distal hypospadias who underwent urethroplasty were recruited from our hospital between January 2021 and March 2023. All patients were randomized in two groups according to the different dressing methods: Group A receiving 3 M antimicrobial incise drape + MEBO (moisture-exposed burn ointment) and Group B receiving absorbent dressing + elastic bandage dressing. The age at surgery, operation time, bleeding during the dressing, postoperative changes in glans color, dressing fell off, comfort of children during the dressing, difficulty in dressing removal, and degree of pain during dressing removal were compared between the two groups. RESULTS: Differences in age at surgery (p = 0.337) and operation time (p = 0.055) were not significant between the two groups. The overall effectiveness of the dressing was better in Group A than that in Group B. Only five cases in Group A had blood leakage after dressing (p = 0.006), and there was no dressing dislocation (p < 0.001) or glans color abnormality (p < 0.001). Moreover, the number of complication cases was less. The overall comfort and pain degree during dressing removal in Group A was better than that in Group B (p < 0.001). CONCLUSION: Postoperative dressing using 3 M antimicrobial incise drape + MEBO can achieve lower incidence rates of bleeding during dressing, postoperative glans darkening, and dressing falling off, a lower pain degree during dressing removal, and a better overall comfort level than those of the control group. This method is cost-effective and clinically safe, which contributes to the postoperative recovery of children with hypospadias and is thus worth promoting and applying.


Assuntos
Bandagens , Hipospadia , Cicatrização , Humanos , Hipospadia/cirurgia , Masculino , Pré-Escolar , Lactente , Procedimentos Cirúrgicos Urológicos Masculinos/métodos , Cuidados Pós-Operatórios/métodos
13.
Polymers (Basel) ; 16(3)2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38337202

RESUMO

Wood is easily affected by decay fungi, mildew fungi, insects, water, UV, and other factors when used outdoors. In particular, mildew on the surface of wood negatively affects the appearance and practical use of wood or wood-based engineered products. In recent years, as a class of popular crystalline materials, metal-organic frameworks (MOFs) have been widely applied in electrochemistry, adsorption, anti-mildew efforts, and other areas. In this study, we first grew a Co-based metal-organic framework (Co-MOF) in situ on a wood surface and subsequently converted the Co-MOF in situ into a cobalt-nickel double hydroxide layer, which formed micro- and nanohierarchical composite structures on the wood surface. The low surface energy of the CoNi-DH@wood was further modified via impregnation with sodium laurate to obtain the superhydrophobic wood (CoNi-DH-La@wood). We characterized the microstructure, chemical composition, water contact angle, and anti-mold properties of the CoNi-DH-La@wood using SEM, XRD, XPS, water contact angle tests, and anti-fungal tests. The SEM, XRD, and XPS results confirmed that the metal-organic framework was coated on the wood surface, with the long-chain sodium laurate grafted onto it. The CoNi-DH-La@wood had a water contact angle of 151°, demonstrating excellent self-cleaning ability. In addition, the fabricated superhydrophobic balsa wood exhibited excellent chemical and environment stability. Lastly, the CoNi-DH-La@wood exhibited excellent anti-mildew properties in a 30-day anti-mildew test because the superhydrophobic coating was successfully coated on the wood surface. In summary, this work presents an attractive strategy for obtaining wood with superhydrophobic properties at room temperature, thereby endowing the wood or wood-based engineered products with excellent anti-mildew properties.

14.
Sci Rep ; 14(1): 11985, 2024 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-38796629

RESUMO

Clear cell renal cell carcinoma (ccRCC) is a malignant tumor of the urinary system. To explore the potential mechanisms of DHODH in ccRCC, we analyzed its molecular characteristics using public databases. TCGA pan-cancer dataset was used to analyze DHODH expression in different cancer types and TCGA ccRCC dataset was used to assess differential expression, prognosis correlation, immune infiltration, single-gene, and functional enrichment due to DHODH. The GSCALite and CellMiner databases were employed to explore drugs and perform molecular docking analysis with DHODH. Protein-protein interaction networks and ceRNA regulatory networks of DHODH were constructed using multiple databases. The effect of DHODH on ccRCC was confirmed in vitro. DHODH was highly expressed in ccRCC. Immune infiltration analysis revealed that DHODH may be involved in regulating the infiltration of immunosuppressive cells such as Tregs. Notably, DHODH influenced ccRCC progression by forming regulatory networks with molecules, such as hsa-miR-26b-5p and UMPS and significantly enhanced the malignant characteristics of ccRCC cells. Several drugs, such as lapatinib, silmitasertib, itraconazole, and dasatinib, were sensitive to DHODH expression and exhibited strong molecular binding with it. Thus, DHODH may promote ccRCC progression and is a candidate effective therapeutic target for ccRCC.


Assuntos
Carcinoma de Células Renais , Biologia Computacional , Di-Hidro-Orotato Desidrogenase , Regulação Neoplásica da Expressão Gênica , Neoplasias Renais , Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , Carcinoma de Células Renais/metabolismo , Humanos , Neoplasias Renais/genética , Neoplasias Renais/patologia , Biologia Computacional/métodos , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Linhagem Celular Tumoral , Mapas de Interação de Proteínas , Simulação de Acoplamento Molecular , Prognóstico , Redes Reguladoras de Genes , MicroRNAs/genética , MicroRNAs/metabolismo
15.
Int J Biol Macromol ; : 133251, 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38945708

RESUMO

Bioactive hydrogels are currently receiving significant attention. In this study, silk fibroin tyramine-modified gelatin hydrogels (SF-TG) with varying degrees of tyramine root substitution were explored. The physicochemical property and biocompatibility of low degree of substitution tyramine-modified gelatin hydrogel (SF-LTG) and high degree of substitution tyramine-modified gelatin hydrogel (SF-HTG) were compared. The results showed that SF-LTG possessed better mechanical property and higher biocompatibility. Thus, SF-LTG was selected as a bioactive matrix and loaded with basic fibroblast growth factor (bFGF); subsequently, curcumin-coupled chitosan rods (CCCRs-EGF) enriched with epidermal growth factor (EGF) were added to obtain SF-LTG-bFGF@CCCRs-EGF hydrogels. The results showed that SF-LTG-bFGF@CCCRs-EGF retained the basic structural and mechanical properties of the SF-LTG matrix gel material and underwent multiple loading and orderly release with different activities while displaying antioxidant, anti-inflammatory, antimicrobial, and pro-cellular proliferation activities and orderly regulation of activity during wound healing. Therefore, the SF-LTG-bFGF@CCCRs-EGF hydrogel is of great value in healing complex wounds.

16.
Langmuir ; 29(37): 11547-53, 2013 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-24001363

RESUMO

A critical challenge in nanoparticle functionalization has been the preparation of polymer-grafted asymmetric (Janus) nanoparticles (diameter < 100 nm). We describe a robust and cyclic method involving a reversible click reaction and "grafting to" strategies to synthesize such nanoparticles. Mechanochemistry was used in a protection-deprotection process to separate nanoparticles cleanly that were anchored to larger particles, and the recovered azide-functionalized larger particles could be recycled as face-blocking moieties. With this combination of strategies, we prepared 15 nm silica nanoparticles that were partially functionalized with poly(methyl methacrylate). Additionally, the unique self-assembly behaviors of the resultant Janus nanoparticles were investigated in different solvents at different concentrations.


Assuntos
Nanopartículas/química , Dióxido de Silício/química , Química Click , Tamanho da Partícula , Polimetil Metacrilato/química , Propriedades de Superfície
17.
Front Oncol ; 13: 1172143, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37554166

RESUMO

Intracranial hemangiopericytoma is a rare invasive tumor originating from mesenchymal fibroblasts and is prone to local recurrence and distant metastasis. This study reports a case of a 27-year-old woman who presented with severe headache, nausea and vomiting for two weeks at thirty-three weeks of gestation. Cranial magnetic resonance imaging (MRI) demonstrated a giant lesion in the bilateral parietal lobe with a size of 5.12x9.19x6.03 cm and severe edema in the surrounding brain tissue. The patient underwent four operations and 3 gamma knife radiosurgery procedures and is recovering well now. The histopathology findings showed hemangiopericytoma and STAT6 and CD34 positivity after the first and second surgeries. Because of tumor progression, the patient received gamma knife radiosurgery at 1, 3, and 4 years after the first operation. Total tumor resection was achieved in the fourth surgery. Nevertheless, the patient showed malignant transformation to from low-grade to high-grade hemangiopericytoma.

18.
Materials (Basel) ; 17(1)2023 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-38204047

RESUMO

Concrete cracking is a significant issue in the global construction industry, and the restraint stress of concrete is a crucial contributing factor to early concrete cracking. The addition of magnesium oxide additive (MEA) to concrete is a method to enhance its crack resistance. In this paper, concrete specimens with four different contents of MEA were tested with a temperature stress testing machine. The deformation characteristics and mechanical properties of concrete with varying contents of MEA were investigated using both free deformation tests and fully constrained deformation tests. The prediction model for the early restrained stress of concrete was developed by integrating the stress relaxation phenomenon of concrete with models for autogenous shrinkage, temperature deformation, and elastic modulus. According to the results, (1) the thermal expansion coefficient exhibits a pattern of initially increasing and subsequently decreasing with the increasing ratio of MEA; (2) the addition of 3% and 8% MEA can offset 23% and 35.1% of the concrete's self-shrinkage, respectively. Nevertheless, when the added MEA content is 5%, the self-shrinkage of concrete increases by 6%; (3) the addition of 3-8% MEA can result in a 0.5-1.67 times increase in the maximum expansion stress of concrete, as well as a 0.5-0.95 times increase in cracking stress; (4) as the MEA content continues to increase, the stress relaxation level of concrete also increases. In comparison to concrete mixed without MEA, the maximum increase in the stress relaxation level of concrete is 65.5%, thereby enhancing the concrete's anti-cracking ability. However, when the MEA dosage reaches a certain threshold, the stress relaxation enhancement brought about by the addition of MEA will no longer be significant; (5) when compared to the experimental data, the established model of early-age constraint stress accurately predicts the tensile constraint stress of concrete.

19.
Int J Biol Macromol ; 244: 125067, 2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37245747

RESUMO

A novel reusable, high-compressible cotton regenerated cellulose/chitosan composite aerogel (RC/CSCA) was prepared using N-methylmorpholine-N-oxide (NMMO) as the green cellulose solvent, and glutaraldehyde (GA) as the crosslinking agent. The regenerated cellulose obtained from cotton pulp could chemically crosslink with chitosan and GA, to form a stable 3D porous structure. The GA played an essential role in preventing shrinkage and preserving the deformation recovery ability of RC/CSCA. Due to the ultralow density (13.92 mg/cm3), thermal stability (above 300 °C), and high porosity (97.36 %), the positively charged RC/CSCA can be used as a novel biocomposite adsorbent for effective and selective removal of toxic anionic dyes from wastewater, showing an excellent adsorption capacity, environmental adaptability, and recyclability. The maximal adsorption capacity and removal efficiency of RC/CSCA for methyl orange (MO) was 742.68 mg/g and 95.83 %.


Assuntos
Quitosana , Poluentes Químicos da Água , Quitosana/química , Corantes/química , Adsorção , Celulose/química , Poluentes Químicos da Água/química
20.
J Hazard Mater ; 454: 131397, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37104952

RESUMO

Cellulose-based carbon aerogels as biodegradable and renewable biomass materials have presented potential applications in oil/water separation. Herein, a novel carbon aerogel composed of natural microfibrils/regenerated cellulose (NM/RCA) was directly prepared by economical hardwood pulp as raw material using a novel co-solvent composed of deep eutectic solvent (DES) and N-methyl morpholine-N-oxide monohydrate (NMMO·H2O). In addition, the morphology and structure of the filiform natural microfibers could be remained after carbonized at 400 â„ƒ, which resulted in a low density (8-10 mg cm-3), high specific surface area (768.89 m2 g-1) and high sorption capability. In addition, the aerogel exhibited high compressibility, outstanding elasticity, excellent fatigue resistance, and recyclability (80.5% height recovery after repeating 100 cycles at the strain of 80%). Due to the morphology and composition of the carbonized microfiber surface, the superhydrophobic materials with a water contact angle of 151.5°, could sorb various oils and organic solvents with 65-133 times its own weight and maintain 91.9% sorption capacity after 25 cycles. In addition, the aerogels could achieve the continuous separation of carbon tetrachloride (CCl4) from water with a high flux rate of 11,718.8 L m-2 h-1. Therefore, our prepared NM/RCA aerogels are anticipated to have broad potential applications in oil purification and contaminant remediation.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA