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Allogeneic chimeric antigen receptor (CAR)-T cells hold great promise for expanding the accessibility of CAR-T therapy, whereas the risks of allograft rejection have hampered its application. Here, we genetically engineered healthy-donor-derived, CD19-targeting CAR-T cells using CRISPR-Cas9 to address the issue of immune rejection and treated one patient with refractory immune-mediated necrotizing myopathy and two patients with diffuse cutaneous systemic sclerosis with these cells. This study was registered at ClinicalTrials.gov (NCT05859997). The infused cells persisted for over 3 months, achieving complete B cell depletion within 2 weeks of treatment. During the 6-month follow-up, we observed deep remission without cytokine release syndrome or other serious adverse events in all three patients, primarily shown by the significant improvement in the clinical response index scores for the two diseases, respectively, and supported by the observations of reversal of inflammation and fibrosis. Our results demonstrate the high safety and promising immune modulatory effect of the off-the-shelf CAR-T cells in treating severe refractory autoimmune diseases.
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The topological physics has sparked intensive investigations into topological lattices in photonic, acoustic, and mechanical systems, powering counterintuitive effects otherwise inaccessible with usual settings. Following the success of these endeavors in classical wave dynamics, there has been a growing interest in establishing their topological counterparts in diffusion. Here, we propose an additional real-space dimension in diffusion, and the system eigenvalues are transformed from "imaginary" to "real." By judiciously tailoring the effective Hamiltonian with coupling networks, localized and delocalized topological modes are realized in heat transfer. Simulations and experiments in active thermal lattices validate the effectiveness of the proposed theoretical strategy. This approach can be applied to establish various topological lattices in diffusion systems, offering insights into engineering topologically protected edge states in dynamic diffusive scenarios.
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Resistance to neoadjuvant chemotherapy leads to poor prognosis of locally advanced rectal cancer (LARC), representing an unmet clinical need that demands further exploration of therapeutic strategies to improve clinical outcomes. Here, we identified a noncanonical role of RB1 for modulating chromatin activity that contributes to oxaliplatin resistance in colorectal cancer (CRC). We demonstrate that oxaliplatin induces RB1 phosphorylation, which is associated with the resistance to neoadjuvant oxaliplatin-based chemotherapy in LARC. Inhibition of RB1 phosphorylation by CDK4/6 inhibitor results in vulnerability to oxaliplatin in both intrinsic and acquired chemoresistant CRC. Mechanistically, we show that RB1 modulates chromatin activity through the TEAD4/HDAC1 complex to epigenetically suppress the expression of DNA repair genes. Antagonizing RB1 phosphorylation through CDK4/6 inhibition enforces RB1/TEAD4/HDAC1 repressor activity, leading to DNA repair defects, thus sensitizing oxaliplatin treatment in LARC. Our study identifies a RB1 function in regulating chromatin activity through TEAD4/HDAC1. It also provides the combination of CDK4/6 inhibitor with oxaliplatin as a potential synthetic lethality strategy to mitigate oxaliplatin resistance in LARC, whereby phosphorylated RB1/TEAD4 can serve as potential biomarkers to guide the patient stratification.
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Terapia Neoadjuvante , Neoplasias Retais , Humanos , Oxaliplatina/farmacologia , Terapia Neoadjuvante/métodos , Neoplasias Retais/tratamento farmacológico , Neoplasias Retais/genética , Quimiorradioterapia/métodos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cromatina , Resultado do Tratamento , Fatores de Transcrição de Domínio TEA , Ubiquitina-Proteína Ligases , Proteínas de Ligação a RetinoblastomaRESUMO
BACKGROUND AND AIMS: Heart failure (HF) is a leading cause of mortality worldwide and characterized by significant co-morbidities and dismal prognosis. Neutrophil extracellular traps (NETs) aggravate inflammation in various cardiovascular diseases; however, their function and mechanism of action in HF pathogenesis remain underexplored. This study aimed to investigate the involvement of a novel VWF-SLC44A2-NET axis in HF progression. METHODS: NET levels were examined in patients with HF and mouse models of transverse aortic constriction (TAC) HF. PAD4 knockout mice and NET inhibitors (GSK-484, DNase I, NEi) were used to evaluate the role of NETs in HF. RNA sequencing was used to investigate the downstream mechanisms. Recombinant human ADAMTS13 (rhADAMTS13), ADAMTS13, and SLC44A2 knockouts were used to identify novel upstream factors of NETs. RESULTS: Elevated NET levels were observed in patients with HF and TAC mouse models of HF. PAD4 knockout and NET inhibitors improved the cardiac function. Mechanistically, NETs induced mitochondrial dysfunction in cardiomyocytes, inhibiting mitochondrial biogenesis via the NE-TLR4-mediated suppression of PGC-1α. Furthermore, VWF/ADAMTS13 regulated NET formation via SLC44A2. Additionally, sacubitril/valsartan amplifies the cardioprotective effects of the VWF-SLC44A2-NET axis blockade. CONCLUSIONS: This study established the role of a novel VWF-SLC44A2-NET axis in regulating mitochondrial homeostasis and function, leading to cardiac apoptosis and contributing to HF pathogenesis. Targeting this axis may offer a potential therapeutic approach for HF treatment.
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BACKGROUND: Low-grade glioma (LGG) has an extremely poor prognosis, and the mechanism leading to malignant development has not been determined. The aim of our study was to clarify the function and mechanism of anoikis and TIMP1 in the malignant progression of LGG. METHODS: We screened 7 anoikis-related genes from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases to construct a prognostic-predicting model. The study assessed the clinical prognosis, pathological characteristics, and immune cell infiltration in both high- and low-risk groups. Additionally, the potential modulatory effects of TIMP1 on proliferation, migration, and anoikis in LGG were investigated both in vivo and in vitro. RESULTS: In this study, we identified seven critical genes, namely, PTGS2, CCND1, TIMP1, PDK4, LGALS3, CDKN1A, and CDKN2A. KaplanâMeier (KâM) curves demonstrated a significant correlation between clinical features and overall survival (OS), and single-cell analysis and mutation examination emphasized the heterogeneity and pivotal role of hub gene expression imbalances in LGG development. Immune cell infiltration and microenvironment analysis further elucidated the relationships between key genes and immune cells. In addition, TIMP1 promoted the malignant progression of LGG in both in vitro and in vivo models. CONCLUSIONS: This study confirmed that TIMP1 promoted the malignant progression of LGG by inhibiting anoikis, providing insights into LGG pathogenesis and potential therapeutic targets.
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Anoikis , Glioma , Inibidor Tecidual de Metaloproteinase-1 , Humanos , Anoikis/genética , Glioma/genética , Glioma/imunologia , Glioma/patologia , Prognóstico , Inibidor Tecidual de Metaloproteinase-1/genética , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/mortalidade , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Camundongos , Masculino , Proliferação de Células/genética , Feminino , Camundongos Nus , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia , Gradação de TumoresRESUMO
Platinum (Pt)-based alloys have received considerable attention due to their compositional variability and unique electrochemical properties. However, homogeneous element distribution at the nanoscale, which is beneficial to various electrocatalytic reactions, is still a great challenge. Herein, a universal approach is proposed to synthesize homogeneously alloyed and size-tunable Pt-based nanoflowers utilizing high gravity technology. Owing to the significant intensification of micro-mixing and mass transfer in unique high gravity shearing surroundings, five typical binary/ternary Pt-based nanoflowers are instantaneously achieved at room temperature. As a proof-of-concept, as-synthesized Platinum-Silver nanoflowers (PtAg NFs) demonstrate excellent catalytic performance and anti-CO poisoning ability for anodic methanol oxidation reaction with high mass activity of 1830 mA mgPt -1, 3.5 and 3.2 times higher than those of conventional beaker products and commercial Pt/C, respectively. The experiment in combination with theory calculations suggest that the enhanced performance is due to additional electronic transmission and optimized d-band center of Pt caused by high alloying degree.
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This study investigates the macroscopic and optical properties of cirrus clouds in the 32N region from July 2016 to May 2017, leveraging data from ground-based lidar observations and CALIOP to overcome the inconsistencies in detected cirrus cloud samples. Through extensive data analysis, statistical characteristics of cirrus clouds were discerned, revealing lidar ratio values of 28.5 ± 10.8 from ground-based lidar and 27.4 ± 11.2 from CALIOP. Validation with a decade of CALIOP data (2008-2018) confirmed these findings, presenting a consistent lidar ratio of 27.4 ± 12.0. A significant outcome of the analysis was the identification of a positive correlation between the lidar ratio and cloud centroid temperature, indicating a gradual decrease in the lidar ratio as temperatures dropped. The study established a fundamental consistency in their macroscopic properties, including cloud base height, cloud top height, cloud thickness, cloud centroid height, and cloud centroid temperature. The results for ground-based lidar (CALIOP) are: 10.0 ± 2.1â km (10.0 ± 2.2â km), 11.8 ± 2.1â km (11.5 ± 2.3â km), 1.87 ± 0.83â km (1.52 ± 0.71â km), and 10.5 ± 2.2â km, -46.9 ± 9.7°C (-47.1 ± 10.0°C).These properties exhibited seasonal variations, with cirrus clouds reaching higher altitudes in summer and lower in winter, influenced by the height of the tropopause. The optical properties of cirrus clouds were also analyzed, showing an annual average optical depth of 0.31 ± 0.35 for ground-based lidar and 0.32 ± 0.44 for CALIOP. The study highlighted the distribution of subvisible, thin, and thick cirrus clouds, with a notable prevalence of subvisible clouds during summer, suggesting their frequent formation above 14â km. Furthermore, the study observed linear growth in geometric thickness and optical depth up to 2.5â km from CALIOP and 2.9â km from ground-based lidar. Maximum optical depth was observed at cloud centroid temperatures of -35°C for CALIOP and -40°C for ground-based lidar, with optical depth decreasing as temperatures fell. This suggests that fully glaciated cirrus clouds exhibit the highest optical depth at warmer temperatures, within the complete glaciation temperature range of -35°C to -40°C.
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Global climate change intensifies the water cycle and makes freshest waters become fresher and vice-versa. But how this change impacts phytoplankton in coastal, particularly harmful algal blooms (HABs), remains poorly understood. Here, we monitored a coastal bay for a decade and found a significant correlation between salinity decline and the increase of Karenia mikimotoi blooms. To examine the physiological linkage between salinity decreases and K. mikimotoi blooms, we compare chemical, physiological and multi-omic profiles of this species in laboratory cultures under high (33) and low (25) salinities. Under low salinity, photosynthetic efficiency and capacity as well as growth rate and cellular protein content were significantly higher than that under high salinity. More strikingly, the omics data show that low salinity activated the glyoxylate shunt to bypass the decarboxylation reaction in the tricarboxylic acid cycle, hence redirecting carbon from CO2 release to biosynthesis. Furthermore, the enhanced glyoxylate cycle could promote hydrogen peroxide metabolism, consistent with the detected decrease in reactive oxygen species. These findings suggest that salinity declines can reprogram metabolism to enhance cell proliferation, thus promoting bloom formation in HAB species like K. mikimotoi, which has important ecological implications for future climate-driven salinity declines in the coastal ocean with respect to HAB outbreaks.
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Mudança Climática , Proliferação Nociva de Algas , Salinidade , Fotossíntese , Fitoplâncton/crescimento & desenvolvimento , Fitoplâncton/fisiologia , Carbono/metabolismo , Carbono/análiseRESUMO
An intelligent delivery nanoformulation could enhance the utilization efficacy, uptake, and translocation of pesticides in plants. Herein, a redox/pH-triggered and fluorescent smart delivery nanoformulation was designed and constructed by using hollow mesoporous organosilica nanoparticles (HMONs) and ZnO quantum dots as the nanocarrier and capping agent, respectively. Boscalid was further loaded to generate Boscalid@HMONs@ZnO with a loading rate of 9.8% for controlling Botrytis cinerea (B. cinerea). The quantity of boscalid released by Boscalid@HMONs@ZnO in a glutathione environment or at pH 3.0 was 1.3-fold and 1.9-fold higher than that in a neutral condition. Boscalid@HMONs@ZnO has 1.7-fold the toxicity index of boscalid technical against B. cinerea in antifungal experiments. Pot experiments revealed that the efficacy of Boscalid@HMONs@ZnO was significantly enhanced more than 1.27-fold compared to commercially available water-dispersible granules of boscalid. Due to the fluorescence properties of Boscalid@HMONs@ZnO, pesticide transport's real-time monitoring of pesticide translocation in tomato plants could be observed by confocal laser scanning microscopy. Fluorescence images revealed that HMONs@ZnO had been effectively transported via treated leaves or roots in tomato plants. This research showed the successful application of HMONs@ZnO as a nanocarrier for controlling disease and offered an effective avenue to explore the real-time tracking of pesticide translocation in plants.
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Botrytis , Nanopartículas , Oxirredução , Óxido de Zinco , Botrytis/efeitos dos fármacos , Nanopartículas/química , Óxido de Zinco/química , Óxido de Zinco/farmacologia , Concentração de Íons de Hidrogênio , Corantes Fluorescentes/química , Compostos de Bifenilo/química , Pontos Quânticos/química , Pontos Quânticos/toxicidade , Solanum lycopersicum/química , Praguicidas/química , Praguicidas/toxicidade , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Compostos de Organossilício/química , Compostos de Organossilício/farmacologia , Liberação Controlada de Fármacos , Fungicidas Industriais/química , Fungicidas Industriais/farmacologia , Niacinamida/análogos & derivadosRESUMO
The structure-property relationship of poly(vinyl chloride) (PVC)/CaCO3 nanocomposites is investigated by all-atom molecular dynamics (MD) simulations. MD simulation results indicate that the dispersity of nanofillers, interfacial bonding, and chain mobility are imperative factors to improve the mechanical performance of nanocomposites, especially toughness. The tensile behavior and dissipated work of the PVC/CaCO3 model demonstrate that 12 wt % CaCO3 modified with oleate anion and dodecylbenzenesulfonate can impart high toughness to PVC due to its good dispersion, favorable interface interaction, and weak migration of PVC chains. Under the guidance of MD simulation, we experimentally prepared a transparent PVC/CaCO3 nanocomposite with good mechanical properties by in situ polymerization of monodispersed CaCO3 in vinyl chloride monomers. Interestingly, experimental tests indicate that the optimum toughness of a nanocomposite (a 368% increase in the elongation at break and 204% improvement of the impact strength) can be indeed realized by adding 12 wt % CaCO3 modified with oleic acid and dodecylbenzenesulfonic acid, which is remarkably consistent with the MD simulation prediction. In short, this work provides a proof-of-concept of using MD simulation to guide the experimental synthesis of PVC/CaCO3 nanocomposites, which can be considered as an example to develop other functional nanocomposites.
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This work reports a highly-strain flexible fiber sensor with a core-shell structure utilizes a unique swelling diffusion technique to infiltrate carbon nanotubes (CNTs) into the surface layer of Ecoflex fibers. Compared with traditional blended Ecoflex/CNTs fibers, this manufacturing process ensures that the sensor maintains the mechanical properties (923% strain) of the Ecoflex fiber while also improving sensitivity (gauge factor is up to 3716). By adjusting the penetration time during fabrication, the sensor can be customized for different uses. As an application demonstration, the fiber sensor is integrated into the glove to develop a wearable gesture language recognition system with high sensitivity and precision. Additionally, the authors successfully monitor the pressure distribution on the curved surface of a soccer ball by winding the fiber sensor along the ball's surface.
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Gestos , Nanotubos de Carbono , Pressão , Propriedades de Superfície , Dispositivos Eletrônicos Vestíveis , Nanotubos de Carbono/química , HumanosRESUMO
BACKGROUND: Great saphenous vein (GSV) valve incompetence is one of the most common manifestations of chronic venous insufficiency (CVI) in the lower limbs. There have been no reported attempts to repair the valve prior to the appearance of varicose morphology. METHOD: We describe two cases. Before surgery, the male patient had obvious pigmentation in the ankle area, and the female patient had obvious pain and swelling in the lower limbs after prolonged standing. Neither patient has obvious varicose veins. After retrograde venography, both patients were found to have severe reflux of the GSV valves (Kinster IV). We performed internal valvuloplasty and sleeve wrapping in two patients. RESULTS: After surgery, both patients had a significant improvement in symptoms and no particular complaints. Vascular ultrasound also suggested a good outcome. CONCLUSION: This surgery is safe and feasible in the treatment of early GSV incompetence, with good short-term results; long-term results remain to be seen.
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To evaluate the inter-observer variability and the intra-observer repeatability of pulmonary transit time (PTT) measurement using contrast-enhanced ultrasound (CEUS) in healthy rabbits, and assess the effects of dilution concentration of ultrasound contrast agents (UCAs) on PTT. Thirteen healthy rabbits were selected, and five concentrations UCAs of 1:200, 1:100, 1:50, 1:10, and 1:1 were injected into the right ear vein. Five digital loops were obtained from the apical 4-chamber view. Four sonographers obtained PTT by plotting the TIC of right atrium (RA) and left atrium (LA) at two time points (T1 and T2). The frame counts of the first appearance of UCAs in RA and LA had excellent inter-observer agreement, with intra-class correlations (ICC) of 0.996, 0.988, respectively. The agreement of PTT among four observers was all good at five different concentrations, with an ICC of 0.758-0.873. The reproducibility of PTT obtained by four observers at T1 and T2 was performed well, with ICC of 0.888-0.961. The median inter-observer variability across 13 rabbits was 6.5% and the median variability within 14 days for 4 observers was 1.9%, 1.7%, 2.2%, 1.9%, respectively; The PTT of 13 healthy rabbits is 1.01 ± 0.18 second. The difference of PTT between five concentrations is statistically significant. The PTT obtained by a concentration of 1:200 and 1:100 were higher than that of 1:1, while there were no significantly differences in PTT of a concentration of 1:1, 1:10, and 1:50. PTT measured by CEUS in rabbits is feasible, with excellent inter-observer and intra-observer reliability and reproducibility, and dilution concentration of UCAs influences PTT results.
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Meios de Contraste , Estudos de Viabilidade , Variações Dependentes do Observador , Ultrassonografia , Animais , Coelhos , Reprodutibilidade dos Testes , Ultrassonografia/métodos , Hexafluoreto de Enxofre/farmacocinética , Circulação Pulmonar/fisiologiaRESUMO
In environments where silent communication is essential, such as libraries and conference rooms, the need for a discreet means of interaction is paramount. Here, we present a single-electrode, contact-separated triboelectric nanogenerator (CS-TENG) characterized by robust high-frequency sensing capabilities and long-term stability. Integrating this TENG onto the inner surface of a mask allows for the capture of conversational speech signals through airflow vibrations, generating a comprehensive dataset. Employing advanced signal processing techniques, including short-time Fourier transform (STFT), Mel-frequency cepstral coefficients (MFCC), and deep learning neural networks, facilitates the accurate identification of speaker content and verification of their identity. The accuracy rates for each category of vocabulary and identity recognition exceed 92% and 90%, respectively. This system represents a pivotal advancement in facilitating secure and efficient unobtrusive communication in quiet settings, with promising implications for smart home applications, virtual assistant technology, and potential deployment in security and confidentiality-sensitive contexts.
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OBJECT: This study aimed to investigate the changes in the translucency and color of four different multi-layered zirconia materials when the sintering temperature were inaccurate. MATERIALS AND METHODS: Two hundred zirconia samples (11 × 11 × 1.0 mm) of four multi-layered zirconia, Upcera TT-GT (UG), Upcera TT-ML (UM), Cercon xt ML (CX), and Lava Esthetic (LE), were divided into five subgroups according to the sintering temperature: L1 (5% lower temperature), L2 (2.5% lower temperature), R (recommended sintering temperature), H2 (2.5% higher temperature), H1 (5% higher temperature). After sintering, color coordinates were measured. Then the translucency parameter (TP) values, and the color differences (between the inaccurate sintering temperature and the recommended temperature) of each zirconia specimen were calculated. Statistical analysis was performed by using three-way ANOVA tests, the one-way ANOVA, and Tukey's post hoc test. RESULTS: Three-way ANOVA results showed that material type, sintering temperature, specimen section, and their interactions significantly influenced the TP values (except for the interactions of specimen section and sintering temperature) (P < .05). TP values of zirconia specimens were significantly different in the inaccurate sintering temperatures (P < .05), except for the cervical and body sections of UG group (P > .05). Compared with recommended sintering temperature, higher sintering temperature caused higher TP values for CX, but lower for LE. Three-way ANOVA results showed that material type, sintering temperature, and their interactions significantly influenced the ∆E00 values (P < .05). There were no significant differences in ∆E00 values of UM and CX groups at different inaccurate sintering temperatures, and were clinical imperception (except for UM-L1) (∆E00 < 1.25). ∆E00 values of all zirconia specimens showed clinically acceptable (∆E00 < 2.23). CONCLUSION: The deviations in sintering temperature significantly influenced the translucency and color of tested multi-layered zirconia. The trends of translucency in the multi-layered zirconia depended on material type and the color changes of all zirconia materials were clinically acceptable at inaccurate sintering temperatures.
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Cerâmica , Zircônio , Humanos , Temperatura , Teste de Materiais , Propriedades de Superfície , CorRESUMO
BACKGROUND: Aortoesophageal fistula (AEF) is a rare condition characterized by communication between the aorta and esophagus. AEF caused by an esophageal foreign body is even rare, and there is currently no recommended standard treatment protocol. We report a case of delayed aortic rupture after the endoscopic removal of a fish bone, which was successfully treated with a combined approach of vascular stenting and thoracic surgery. CASE PRESENTATION: A 33-year-old man presented to the hospital after experiencing chest discomfort for 3 days following the accidental ingestion of a fish bone. Under endoscopic guidance, the fish bone was successfully removed, and the patient was subsequently admitted for medical therapy. On the fourth postoperative day, the patient suddenly developed hematemesis, and chest computed tomography angiography revealed the presence of an AEF. This necessitated urgent intervention; hence, thoracic surgery was performed and a vascular-covered stent was placed. Following the surgical procedure, the patient received active medical treatment, recovered well, and was successfully discharged from the hospital. CONCLUSIONS: In patients with esophageal perforation caused by foreign bodies, hospitalization for observation, computed tomography angiography examination, early use of antibiotics, and careful assessment of aortic damage are advised. Thoracic endovascular aortic repair and esophageal rupture repair may have benefits for the treatment of AEF.
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Doenças da Aorta , Fístula Esofágica , Fístula Vascular , Masculino , Animais , Humanos , Adulto , Cirurgia Torácica Vídeoassistida/efeitos adversos , Doenças da Aorta/cirurgia , Doenças da Aorta/complicações , Fístula Esofágica/cirurgia , Fístula Esofágica/complicações , Hemorragia Gastrointestinal , Stents/efeitos adversos , Fístula Vascular/diagnóstico por imagem , Fístula Vascular/etiologia , Fístula Vascular/cirurgiaRESUMO
A 46-year-old woman with stage 5 chronic kidney disease was unable to undergo hemodialysis treatment due to thoracic central venous obstruction (TCVO) and blockage of the tunneled cuffed catheter. This patient also presented with symptoms of TCVO. When percutaneous procedure was not possible, we resolved the obstruction with the innominate-to-right-atrial bypass grafting technique under extracorporeal circulation. There are few reports on this surgical approach. In terms of patient prognosis, this may be an effective solution to this problem.
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Obstruction and/or reflux compromise during venous emptying can facilitate different pathophysiologies in chronic venous insufficiency (CVI). We present a patient with persistent lower limb CVI edema caused by post-thrombotic syndrome (PTS), who responded well to femoral vein valve therapy via axillary vein bypass after unsuccessful valvuloplasty, and led a normal life. During a 12 month observation period, bridging vessels completely restored original anatomical structures. In a literature study, no similar surgeries were reported, but we show that this operation may be feasible in selected patients.
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Insuficiência Venosa , Humanos , Insuficiência Venosa/cirurgia , Veia Femoral/cirurgia , Extremidade Inferior/irrigação sanguínea , Edema/etiologiaRESUMO
Combination of taxa and function can provide a more comprehensive picture on human-induced microbial homogenization. Here, we obtained 2.58 billion high-throughput sequencing reads and 479 high-quality metagenome-assembled genomes (MAGs) of planktonic microbial communities in a subtropical river for 5 years. We found the microbial taxa homogenization and functional homogenization were uncoupled. Although human activities in downstream sites significantly decreased the taxonomic diversity of non-abundant ASV communities (16S rRNA gene amplicon sequence variants), they did not significantly decrease the taxonomic diversity of abundant ASV and total observed MAG communities. However, the total observed MAG communities in downstream sites tended to homogenize into some specific taxa which encode human-activity-related functional genes, such as nutrient cycles, greenhouse gas emission, antibiotic and arsenic resistance. Those specific MAGs with high taxonomic diversity caused the weak heterogenization of total observed MAG communities in downstream sites. Moreover, functional homogenization promoted the synchrony among downstream MAGs, and these MAGs constructed some specific network modules might to synergistically execute or resist the human-activity-related functions. High synchrony also led to the tandem effects among MAGs and thus decreased community stability. Overall, our findings revealed the links of microbial taxa, functions and stability under human activity impacts, and provided a strong evidence to encourage us re-thinking biotic homogenization based on microbial taxa and their functional attributes.
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Bactérias , Microbiota , Humanos , Bactérias/genética , RNA Ribossômico 16S/genética , Metagenoma , Microbiota/genética , RiosRESUMO
Algicidal bacteria exhibit promising potential against harmful algal blooms (HABs); however, their application has been limited due to their limited algicidal activity. This study demonstrates the enhanced algicidal activity of Alteromonas sp. FDHY-CJ bacteria against harmful Skeletonema costatum using a 5 L fermenter. Utilizing this refined framework increased the OD600 value and algal cell mortality by 6.50 and 2.88 times, respectively, compared to non-optimized culture cultivated in a flask using marine broth 2216E medium. The mechanism of action involves significant inhibition of algal photosynthetic efficiency with concurrent degradation of photosynthetic pigments. Relative to the non-optimized group, the optimized bacterial treatment led to a significant increase in H2O2 and MDA (malondialdehyde) by 19.54 and 4.22-fold, respectively, and resulted in membrane damage. The culture optimization procedure yielded effectual algicidal substances capable of considerably reducing the severity of S. costatum HABs through cell membrane disruption.