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1.
IEEE Trans Med Imaging ; PP2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39012728

RESUMO

Time-of-flight magnetic resonance angiography (TOF-MRA) is the least invasive and ionizing radiation-free approach for cerebrovascular imaging, but variations in imaging artifacts across different clinical centers and imaging vendors result in inter-site and inter-vendor heterogeneity, making its accurate and robust cerebrovascular segmentation challenging. Moreover, the limited availability and quality of annotated data pose further challenges for segmentation methods to generalize well to unseen datasets. In this paper, we construct the largest and most diverse TOF-MRA dataset (COSTA) from 8 individual imaging centers, with all the volumes manually annotated. Then we propose a novel network for cerebrovascular segmentation, namely CESAR, with the ability to tackle feature granularity and image style heterogeneity issues. Specifically, a coarse-to-fine architecture is implemented to refine cerebrovascular segmentation in an iterative manner. An automatic feature selection module is proposed to selectively fuse global long-range dependencies and local contextual information of cerebrovascular structures. A style self-consistency loss is then introduced to explicitly align diverse styles of TOF-MRA images to a standardized one. Extensive experimental results on the COSTA dataset demonstrate the effectiveness of our CESAR network against state-of-the-art methods. We have made 6 subsets of COSTA with the source code online available, in order to promote relevant research in the community.

2.
J Hazard Mater ; 476: 135160, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38991646

RESUMO

The heterotrophic nitrification-aerobic denitrification (HNAD) strain Exiguobacterium H1 (H1) was isolated in this study. The changes in nitrogen metabolism functions of H1 strain were discussed in presence of disinfectants chloroxylenol (PCMX) and benzethonium chloride (BEC) alone and combined pollution (PCMX+BEC). The H1 strain could use NH4+-N, NO2--N and NO3--N as nitrogen sources and had good nitrogen removal performance under conditions of C/N ratio 25, pH 5-8, 25-35 oC and sodium acetate as carbon. PCMX and BEC alone exhibited hormesis effects on H1 strain which promoted the growth of H1 strain at low concentrations but inhibited it at high concentrations, and combined pollution showed synergistic inhibitory on H1 strain. H1 strain owned a full nitrogen metabolic pathway according to functional genes quantification. PCMX encouraged nitrification process of H1, while BEC and combined pollution mostly blocked nitrogen removal. PCMX, but not BEC, mainly led to the enrichment of resistance genes. These findings will aid in systematic assessment of contaminant tolerance characteristics of HNAD strain and its application prospects.

3.
Front Pharmacol ; 15: 1294122, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38948463

RESUMO

Introduction: Premenstrual dysphoric disorder (PMDD), a severe form of premenstrual syndrome (PMS), is a serious health disorder that affects patient moods. It is caused by cyclic psychological symptoms and its pathogenesis is still unclear. Abnormalities in the basolateral amygdala (BLA) orexin system, which are important causes of the development of depressive mood, have not been reported in PMDD, so exploring its intrinsic mechanisms is meaningful for enriching the pathomechanisms of PMDD. Methods: High performance liquid chromatography was used for the determination of the active ingredients of Jingqianshu granules. Developing a rat model of premenstrual depression using the forced swimming test (FST). The experiment consisted of two parts. In Part 1, the rats were divided into the control group, the model group, the model + Jingqianshu group, and the model + fluoxetine group. The FST, open field test, and elevated plus maze test, were used to assess the behavior of the rats as well as to evaluate the effect of drug intervention. Immunofluorescence and RT-qPCR were used to detect the expression of orexin and its receptors OX1R and OX2R genes and proteins. The expression of Toll-like receptor 4, nuclear factor kappa-B, tumor necrosis factor-α, interleukin 6, and interleukin-1ß in the BLA brain region was detected by Western-Blot. In part 2, the rats were injected intracerebrally with orexin-A. Observe the behavioral activities of rats in the control group, model group, and model+orexin-A group. Immunofluorescence was used to detect microglia in the BLA area of rats, and the expression levels of the above inflammatory factors were detected by Western-Blot. Results: The five components of Jingqianshu granules are: paeoniflorin, erulic acid, liquiritin, hesperidin, and paeonol. During the estrous cycle, rats exhibited depressive-like behavior during the non-receptive phase of the behavioral test, which disappeared during the receptive phase. Immunofluorescence and RT-qPCR showed reduced gene and protein expression of orexin, OX1R, and OX2R in the BLA region of rats in the model group.WB showed elevated levels of inflammatory factors. All returned to control levels after drug treatment. In part 2, injection of orexin-A into the BLA brain region of model rats resulted in reduced immunoreactivity of microglia and decreased expression levels of inflammatory factors. Discussion: Jianqianshu granules can achieve the purpose of treating premenstrual depression by regulating orexin-mediated inflammatory factors, which provides a new idea for further research on the pathogenesis of PMDD. However, the current study is still preliminary and the pathogenesis of PMDD is complex. Therefore, more in-depth exploration is needed.

4.
J Periodontal Res ; 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38991951

RESUMO

Periodontitis is widely acknowledged as the most prevalent type of oral inflammation, arising from the dynamic interplay between oral pathogens and the host's immune responses. It is also recognized as a contributing factor to various systemic diseases. Dysbiosis of the oral microbiota can significantly alter the composition and diversity of the gut microbiota. Researchers have delved into the links between periodontitis and systemic diseases through the "oral-gut" axis. However, whether the associations between periodontitis and the gut microbiota are simply correlative or driven by causative mechanistic interactions remains uncertain. This review investigates how dysbiosis of the gut microbiota impacts periodontitis, drawing on existing preclinical and clinical data. This study highlights potential mechanisms of this interaction, including alterations in subgingival microbiota, oral mucosal barrier function, neutrophil activity, and abnormal T-cell recycling, and offers new perspectives for managing periodontitis, especially in cases linked to systemic diseases.

5.
Clin Genitourin Cancer ; 22(5): 102114, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38959838

RESUMO

BACKGROUND: To evaluate the overall survival (OS) and construct a nomogram to predict the OS of patients with penile squamous cell carcinoma (PSCC). METHODS: This retrospective study analyzed data of patients with PSCC from the First Affiliated Hospital of Soochow University between 2012 and 2022. R software was used to explore factors influencing OS in PSCC. Kaplan-Meier method and log-rank test were employed for OS estimation. Univariate and multivariate Cox proportional hazards regression analyses were performed to identify these factors. A nomogram was created to identify the independent prognostic factors. The model was evaluated by concordance index, receiver operating characteristic (ROC) curves, and calibration plots. RESULTS: A total of 159 patients with T1/T2 PSCC were included in the analysis. Patients with T2/N2 stage, older age, larger tumor size, high preoperative systemic immune-inflammation index (SII), and poor preoperative nutrition had a higher incidence of poor OS. Age, T/N stage, tumor size, and SII were identified as independent prognostic indicators. A prognostic nomogram was formulated, and its predictive accuracy for estimating OS in PSCC patients was validated through ROC curves and calibration plots. CONCLUSION: The nomograms, based on age, T/N stage, tumor size, and high preoperative SII, provide a valuable tool for predicting 1-, 2-, and 3-year OS in patients with T1/T2 PSCC without distant metastases.

6.
Curr Protoc ; 4(7): e1038, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38967962

RESUMO

A variety of metals, e.g., lead (Pb), cadmium (Cd), and lithium (Li), are in the environment and are toxic to humans. Hematopoietic stem cells (HSCs) reside at the apex of hematopoiesis and are capable of generating all kinds of blood cells and self-renew to maintain the HSC pool. HSCs are sensitive to environmental stimuli. Metals may influence the function of HSCs by directly acting on HSCs or indirectly by affecting the surrounding microenvironment for HSCs in the bone marrow (BM) or niche, including cellular and extracellular components. Investigating the impact of direct and/or indirect actions of metals on HSCs contributes to the understanding of immunological and hematopoietic toxicology of metals. Treatment of HSCs with metals ex vivo, and the ensuing HSC transplantation assays, are useful for evaluating the impacts of the direct actions of metals on the function of HSCs. Investigating the mechanisms involved, given the rarity of HSCs, methods that require large numbers of cells are not suitable for signal screening; however, flow cytometry is a useful tool for signal screening HSCs. After targeting signaling pathways, interventions ex vivo and HSCs transplantation are required to confirm the roles of the signaling pathways in regulating the function of HSCs exposed to metals. Here, we describe protocols to evaluate the mechanisms of direct and indirect action of metals on HSCs. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Identify the impact of a metal on the competence of HSCs Basic Protocol 2: Identify the impact of a metal on the lineage bias of HSC differentiation Basic Protocol 3: Screen the potential signaling molecules in HSCs during metal exposure Alternate Protocol 1: Ex vivo treatment with a metal on purified HSCs Alternate Protocol 2: Ex vivo intervention of the signaling pathway regulating the function of HSCs during metal exposure.


Assuntos
Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/citologia , Animais , Metais/toxicidade , Camundongos , Humanos , Transplante de Células-Tronco Hematopoéticas , Citometria de Fluxo/métodos
7.
J Hazard Mater ; 476: 135197, 2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-39018601

RESUMO

Benzylalkyldimethylethyl ammonium compounds (BAC) and polyvinyl chloride microplastics (PVC MPs), as the frequently detected pollutants in wastewater treatment plants (WWTPs), have attracted more concerns on their ecosystem risks. Therefore, this study investigated how the sulfur autotrophic denitrification (SAD) system responded to the single and joint stress of PVC MPs (1, 10 and 100 mg/L) and BAC (0.5, 5 and 10 mg/L). After 100 days of operation, the presence of 10 mg/L BAC led to obviously inhibitory effects on system performance and microbial metabolic activity. And the additions of PVC MPs or/and BAC stimulated the proliferation of intracellular resistance genes (RGs), whereas exposure to BAC increased the abundances of extracellular RGs and free RGs in water more significantly. Compared to the joint stress, BAC single stress resulted in higher abundances of free RGs in water, which further increased the risk of RGs propagation. Moreover, the interaction between mobile genetic elements and extracellular polymeric substances further increased the spread of RGs. Pathogens might be the potential hosts of RGs and enriched in SAD system and plastisphere, thereby leading to more serious ecological risks. This study will broaden the understanding of the environmental hazards posed by PVC MPs and BAC in WWTPs.

8.
J Nanobiotechnology ; 22(1): 320, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38849820

RESUMO

Simultaneously modulating the inflammatory microenvironment and promoting local bone regeneration is one of the main challenges in treating bone defects. In recent years, osteoimmunology has revealed that the immune system plays an essential regulatory role in bone regeneration and that macrophages are critical components. In this work, a mussel-inspired immunomodulatory and osteoinductive dual-functional hydroxyapatite nano platform (Gold/hydroxyapatite nanocomposites functionalized with polydopamine - PDA@Au-HA) is developed to accelerate bone tissues regeneration by regulating the immune microenvironment. PDA coating endows nanomaterials with the ability to scavenge reactive oxygen species (ROS) and anti-inflammatory properties, and it also exhibits an immunomodulatory ability to inhibit M1 macrophage polarization and activate M2 macrophage secretion of osteogenesis-related cytokines. Most importantly, this nano platform promotes the polarization of M2 macrophages and regulates the crosstalk between macrophages and pre-osteoblast cells to achieve bone regeneration. Au-HA can synergistically promote vascularized bone regeneration through sustained release of Ca and P particles and gold nanoparticles (NPs). This nano platform has a synergistic effect of good compatibility, scavenging of ROS, and anti-inflammatory and immunomodulatory capability to accelerate the bone repair process. Thus, our research offers a possible therapeutic approach by exploring PDA@Au-HA nanocomposites as a bifunctional platform for tissue regeneration.


Assuntos
Bivalves , Regeneração Óssea , Durapatita , Ouro , Indóis , Macrófagos , Osteogênese , Regeneração Óssea/efeitos dos fármacos , Durapatita/química , Durapatita/farmacologia , Animais , Camundongos , Ouro/química , Ouro/farmacologia , Bivalves/química , Células RAW 264.7 , Macrófagos/efeitos dos fármacos , Indóis/química , Indóis/farmacologia , Osteogênese/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Polímeros/química , Polímeros/farmacologia , Nanocompostos/química , Nanopartículas Metálicas/química , Osteoblastos/efeitos dos fármacos , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Fatores Imunológicos/farmacologia , Fatores Imunológicos/química , Citocinas/metabolismo
9.
Nano Lett ; 24(23): 6974-6980, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38829211

RESUMO

The plateau phase transition in quantum anomalous Hall (QAH) insulators corresponds to a quantum state wherein a single magnetic domain gives way to multiple domains and then reconverges back to a single magnetic domain. The layer structure of the sample provides an external knob for adjusting the Chern number C of the QAH insulators. Here, we employ molecular beam epitaxy to grow magnetic topological insulator multilayers and realize the magnetic field-driven plateau phase transition between two QAH states with odd Chern number change ΔC. We find that critical exponents extracted for the plateau phase transitions with ΔC = 1 and ΔC = 3 in QAH insulators are nearly identical. We construct a four-layer Chalker-Coddington network model to understand the consistent critical exponents for the plateau phase transitions with ΔC = 1 and ΔC = 3. This work will motivate further investigations into the critical behaviors of plateau phase transitions with different ΔC in QAH insulators.

10.
J Pers Med ; 14(6)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38929779

RESUMO

This study aimed to investigate the impact of various vasculopathies alongside left ventricular hypertrophy (LVH) on cardiovascular risk in the elderly. This prospective cohort study included 3339 older adults from the Northern Shanghai Study, classified into four mutually exclusive left ventricular (LV) geometry groups based on echocardiographic data: normal geometry, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy. Vasculopathy was categorized into three primary types: arteriosclerosis, atherosclerosis, and renal senescence. Major adverse cardiovascular events (MACEs) were defined as non-fatal acute myocardial infarction, non-fatal stroke, and cardiovascular deaths according to ICD-10 codes. Over a median follow-up period of 5.7 years, 221 incident cases of MACEs were identified. Concentric hypertrophy exhibited the highest prevalence of hypertension, the most significant increase in vascular stiffness, and the highest rate of MACEs. The adjusted Cox regression analysis showed that eccentric hypertrophy is associated with an increased risk of MACEs (HR: 1.638 [95% CI: 1.151-2.331], p = 0.006), while concentric hypertrophy shows an even higher risk (HR: 1.751 [95% CI: 1.127-2.721], p = 0.013). Conversely, concentric remodeling was not significantly associated with an increased risk of MACEs. Renal senescence presents a moderate but significant risk for MACEs, with an HR of 1.361 (95% CI: 1.019-1.819; p = 0.037) when adjusted for LVH. The Kaplan-Meier analysis showed that patients with LVH and multiple vasculopathies experience the most significant decrease in survival probability (log-rank p < 0.001). The subgroup analysis revealed that LVH significantly raises the risk of MACEs, especially in older males with hypertension, diabetes, or vasculopathy. This study reinforces the importance of LVH as a predictor of adverse cardiovascular outcomes and underscores the compounded risk associated with the presence of multiple vasculopathies. Additionally, it highlights renal senescence as a distinct and independent risk factor for MACEs, separate from LVH.

11.
J Hazard Mater ; 476: 135070, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38944986

RESUMO

Dialkyldimethyl ammonium compound (DADMAC) is widely used in daily life as a typical disinfectant and often co-exists with the heavy metal zinc in sewage environments. This study investigated the effects of co-exposure to zinc (1 mg/L) and DADMAC (0.2-5 mg/L) on the performance, bacterial community, and resistance genes (RGs) in a partial sulfur autotrophic denitrification coupled with anaerobic ammonium oxidation (PSAD-Anammox) system in a sequencing batch moving bed biofilm reactor for 150 days. Co-exposure to zinc and low concentration (0.2 mg/L) DADMAC did not affect the nitrogen removal ability of the PASD-Anammox system, but increased the abundance and transmission risk of free RGs in water. Co-exposure to zinc and medium-to-high (2-5 mg/L) DADMAC led to fluctuations in and inhibition of nitrogen removal, which might be related to the enrichment of heterotrophic denitrifying bacteria dominated by Denitratisoma. Co-exposure to zinc and high concentration DADMAC (5 mg/L) stimulated the secretion of extracellular polymeric substances and increased the proliferation risk of intracellular RGs in sludge. This study provided insights into the application of PSAD-Anammox system and the ecological risks of wastewater containing zinc and DADMAC.

12.
ACS Biomater Sci Eng ; 10(7): 4093-4113, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38829538

RESUMO

Titanium (Ti) and its alloys are widely used biomaterials in bone repair. Although these biomaterials possess stable properties and good biocompatibility, the high elastic modulus and low surface activity of Ti implants have often been associated with infection, inflammation, and poor osteogenesis. Therefore, there is an urgent need to modify the surface of Ti implants, where changes in surface morphology or coatings loading can confer specific functions to help them adapt to the osseointegration formation phase and resist bacterial infection. This can further ensure a healthy microenvironment for bone regeneration as well as the promotion of immunomodulation, angiogenesis, and osteogenesis. Therefore, in this review, we evaluated various functional Ti implants after surface modification, both in terms of static modifications and dynamic response strategies, mainly focusing on the synergistic effects of antimicrobial activities and functionalized osteogenic. Finally, the current challenges and future perspectives are summarized to provide innovative and effective solutions for osseointegration and bone defect repair.


Assuntos
Antibacterianos , Osseointegração , Osteogênese , Próteses e Implantes , Propriedades de Superfície , Titânio , Titânio/química , Titânio/farmacologia , Osseointegração/efeitos dos fármacos , Humanos , Osteogênese/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Animais , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Regeneração Óssea/efeitos dos fármacos
13.
Nano Lett ; 24(26): 7962-7971, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38885199

RESUMO

The interface of two materials can harbor unexpected emergent phenomena. One example is interface-induced superconductivity. In this work, we employ molecular beam epitaxy to grow a series of heterostructures formed by stacking together two nonsuperconducting antiferromagnetic materials, an intrinsic antiferromagnetic topological insulator MnBi2Te4 and an antiferromagnetic iron chalcogenide FeTe. Our electrical transport measurements reveal interface-induced superconductivity in these heterostructures. By performing scanning tunneling microscopy and spectroscopy measurements, we observe a proximity-induced superconducting gap on the top surface of the MnBi2Te4 layer, confirming the coexistence of superconductivity and antiferromagnetism in the MnBi2Te4 layer. Our findings will advance the fundamental inquiries into the topological superconducting phase in hybrid devices and provide a promising platform for the exploration of chiral Majorana physics in MnBi2Te4-based heterostructures.

14.
ACS Synth Biol ; 13(6): 1956-1962, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38860508

RESUMO

Escherichia coli, one of the most efficient expression hosts for recombinant proteins, is widely used in chemical, medical, food, and other industries. De novo engineering of gene regulation circuits and cell density-controlled E. coli cell lysis are promising directions for the release of intracellular bioproducts. Here, we developed an E. coli autolytic system, named the quorum sensing-mediated bacterial autolytic (QS-BA) system, by incorporating an acyl-homoserine lactone (AHL)-based YasI/YasR-type quorum sensing circuit from Pseudoalteromonas into E. coli cells. The results showed that the E. coli QS-BA system can release the intracellular bioproducts into the cell culture medium in terms of E. coli cell density, which offers an environmentally-friendly, economical, efficient, and flexible E. coli lysis platform for production of recombinant proteins. The QS-BA system has the potential to serve as an integrated system for the large-scale production of target products in E. coli for medical and industrial applications.


Assuntos
Escherichia coli , Percepção de Quorum , Proteínas Recombinantes , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/genética , Acil-Butirolactonas/metabolismo , Pseudoalteromonas/metabolismo , Pseudoalteromonas/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
15.
IEEE Trans Image Process ; 33: 3620-3633, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38787669

RESUMO

With the benefit of deep learning techniques, recent researches have made significant progress in image compression artifacts reduction. Despite their improved performances, prevailing methods only focus on learning a mapping from the compressed image to the original one but ignore the intrinsic attributes of the given compressed images, which greatly harms the performance of downstream parsing tasks. Different from these methods, we propose to decouple the intrinsic attributes into two complementary features for artifacts reduction, i.e., the compression-insensitive features to regularize the high-level semantic representations during training and the compression-sensitive features to be aware of the compression degree. To achieve this, we first employ adversarial training to regularize the compressed and original encoded features for retaining high-level semantics, and we then develop the compression quality-aware feature encoder for compression-sensitive features. Based on these dual complementary features, we propose a Dual Awareness Guidance Network (DAGN) to utilize these awareness features as transformation guidance during the decoding phase. In our proposed DAGN, we develop a cross-feature fusion module to maintain the consistency of compression-insensitive features by fusing compression-insensitive features into the artifacts reduction baseline. Our method achieves an average 2.06 dB PSNR gains on BSD500, outperforming state-of-the-art methods, and only requires 29.7 ms to process one image on BSD500. Besides, the experimental results on LIVE1 and LIU4K also demonstrate the efficiency, effectiveness, and superiority of the proposed method in terms of quantitative metrics, visual quality, and downstream machine vision tasks.

16.
Biomater Adv ; 161: 213892, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38795472

RESUMO

Guided bone regeneration (GBR) stands as an essential modality for craniomaxillofacial bone defect repair, yet challenges like mechanical weakness, inappropriate degradability, limited bioactivity, and intricate manufacturing of GBR membranes hindered the clinical efficacy. Herein, we developed a Janus bacterial cellulose(BC)/MXene membrane through a facile vacuum filtration and etching strategy. This Janus membrane displayed an asymmetric bilayer structure with interfacial compatibility, where the dense layer impeded cell invasion and the porous layer maintained stable space for osteogenesis. Incorporating BC with Ti3C2Tx MXene significantly enhanced the mechanical robustness and flexibility of the material, enabling clinical operability and lasting GBR membrane supports. It also contributed to a suitable biodegradation rate, which aligned with the long-term bone repair period. After demonstrating the desirable biocompatibility, barrier role, and osteogenic capability in vitro, the membrane's regenerative potential was also confirmed in a rat cranial defect model. The excellent bone repair performance could be attributed to the osteogenic capability of MXene nanosheets, the morphological cues of the porous layer, as well as the long-lasting, stable regeneration space provided by the GBR membrane. Thus, our work presented a facile, robust, long-lasting, and biodegradable BC/MXene GBR membrane, offering a practical solution to craniomaxillofacial bone defect repair.


Assuntos
Regeneração Óssea , Celulose , Regeneração Tecidual Guiada , Osteogênese , Titânio , Regeneração Óssea/efeitos dos fármacos , Celulose/química , Animais , Ratos , Titânio/química , Titânio/farmacologia , Regeneração Tecidual Guiada/métodos , Osteogênese/efeitos dos fármacos , Membranas Artificiais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Ratos Sprague-Dawley , Humanos , Porosidade , Crânio/cirurgia , Crânio/efeitos dos fármacos , Crânio/lesões
17.
Materials (Basel) ; 17(10)2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38793400

RESUMO

In the selective laser melting (SLM) process, adjusting process parameters contributes to achieving the desired molten pool morphology, thereby enhancing the mechanical properties and dimensional accuracy of manufactured components. The parameter window characterizing the relationship between molten pool morphology and process parameters serves as an effective tool to improve SLM's forming quality. This work established a mesoscale model of the SLM process for a GH3625 alloy based on the discrete element method (DEM) and computational fluid dynamics (CFD) to simulate the forming process of a single molten track. Subsequently, the formation mechanism and evolution process of the molten pool were revealed. The effects of laser power and scanning speed on the molten pool size and molten track morphology were analyzed. Finally, a parameter window was established from the simulation results. The results indicated that reducing the scanning speed and increasing the laser power would lead to an increase in molten pool depth and width, resulting in the formation of an uneven width in the molten track. Moreover, accelerating the scanning speed and decreasing the laser power cause a reduction in molten pool depth and width, causing narrow and discontinuous molten tracks. The accuracy of the simulation was validated by comparing experimental and simulated molten pool sizes.

18.
Materials (Basel) ; 17(9)2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38730770

RESUMO

During thermal deformation, grain coarsening due to grain growth and grain refinement resulting from dynamic recrystallization (DRX) collectively influence the deformed grain size. To investigate the separative and comprehensive effects of the two mechanisms in the Ni-38Cr-3.8Al alloy, grain growth experiments and isothermal compression tests were conducted. Kinetics models for grain growth and DRX behaviors were established based on the experimental data, which were integrated with finite element (FE) techniques to simulate the evolution of grain size throughout the entire thermal compression process. The effects of grain coarsening and grain refinement during this process were separated and quantified based on the simulation data. The results revealed that grain coarsening predominated during the heating and holding stages, with a longer holding time and higher holding temperatures intensifying this effect. However, during the compression stage, grain coarsening and grain refinement co-existed, and their competition was influenced by deformation parameters. Specifically, grain refinement dominated at strain rates exceeding 0.1 s-1, while grain coarsening dominated at lower strain rates (<0.1 s-1) and higher deformation temperatures (>1373 K). The simulated grain sizes closely matched the experimental observations.

19.
bioRxiv ; 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38746445

RESUMO

Improvements in single-cell whole-genome sequencing (scWGS) assays have enabled detailed characterization of somatic copy number alterations (CNAs) at the single-cell level. Yet, current computational methods are mostly designed for detecting chromosome-scale changes in cancer samples with low sequencing coverage. Here, we introduce HiScanner (High-resolution Single-Cell Allelic copy Number callER), which combines read depth, B-allele frequency, and haplotype phasing to identify CNAs with high resolution. In simulated data, HiScanner consistently outperforms state-of-the-art methods across various CNA types and sizes. When applied to high-coverage scWGS data from human brain cells, HiScanner shows a superior ability to detect smaller CNAs, uncovering distinct CNA patterns between neurons and oligodendrocytes. For 179 cells we sequenced from longitudinal meningioma samples, integration of CNAs with point mutations revealed evolutionary trajectories of tumor cells. These findings show that HiScanner enables accurate characterization of frequency, clonality, and distribution of CNAs at the single-cell level in both non-neoplastic and neoplastic cells.

20.
J Gastrointest Oncol ; 15(2): 585-596, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38756641

RESUMO

Background: Platinum-based chemotherapy combined with immune checkpoint inhibitors (ICIs) is now becoming the standard first-line therapy for human epidermal growth factor receptor 2 (HER2)-negative advanced gastric cancer (AGC). In China, paclitaxel has shown good efficacy and tolerability in AGC as an alternative for first-line therapy. Combining ICIs with paclitaxel-based chemotherapy may lead to improved tumor immune microenvironment, but evidence in paclitaxel combing with ICIs as first-line regimen is lacking. This multicenter, retrospective research aims to compare effectiveness and tolerability of paclitaxel-based chemotherapy combined with ICIs versus chemotherapy alone as a first-line treatment of HER2-negative AGC in a real-world setting. Methods: Eighty-six patients with HER2-negative AGC were included from 2017 to 2022. Among them, 57 patients received paclitaxel-based chemotherapy plus ICIs, and 29 patients received paclitaxel-based chemotherapy alone. We compared the efficacy and incidence of adverse events between the two therapy options. Results: Significant improvements in median progression-free survival (PFS) (8.77 versus 7.47 months; P=0.04) and median overall survival (OS) (15.70 versus 14.33 months; P=0.04) were observed in the ICIs combined with paclitaxel-based chemotherapy group. The use of ICIs also significantly prolonged the duration of response (DOR) (7.47 versus 4.59 months; P=0.02). Meanwhile, the ICIs plus chemotherapy group demonstrated significantly improved objective response rate (ORR) (50.9% vs. 27.6%; P=0.03) and disease control rate (DCR) (98.3% vs. 82.8%; P=0.01), and the side effects were tolerable. Conclusions: In summary, for HER2-negative AGC, ICIs plus paclitaxel-based chemotherapy is effective with mild toxicities, which should be considered as an alternative first-line therapy regimen.

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