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BACKGROUND: Vascular calcification is a common vascular lesion associated with high morbidity and mortality from cardiovascular events. Antibiotics can disrupt the gut microbiota (GM) and have been shown to exacerbate or attenuate several human diseases. However, whether antibiotic-induced GM disruption affects vascular calcification remains unclear. METHODS: Antibiotic cocktail (ABX) treatment was utilized to test the potential effects of antibiotics on vascular calcification. The effects of antibiotics on GM and serum short-chain fatty acids (SCFAs) in vascular calcification mice were analyzed using 16 S rRNA gene sequencing and targeted metabolomics, respectively. Further, the effects of acetate, propionate and butyrate on vascular calcification were evaluated. Finally, the potential mechanism by which acetate inhibits osteogenic transformation of VSMCs was explored by proteomics. RESULTS: ABX and vancomycin exacerbated vascular calcification. 16 S rRNA gene sequencing and targeted metabolomics analyses showed that ABX and vancomycin treatments resulted in decreased abundance of Bacteroidetes in the fecal microbiota of the mice and decreased serum levels of SCFAs. In addition, supplementation with acetate was found to reduce calcium salt deposition in the aorta of mice and inhibit osteogenic transformation in VSMCs. Finally, using proteomics, we found that the inhibition of osteogenic transformation of VSMCs by acetate may be related to glutathione metabolism and ubiquitin-mediated proteolysis. After adding the glutathione inhibitor Buthionine sulfoximine (BSO) and the ubiquitination inhibitor MG132, we found that the inhibitory effect of acetate on VSMC osteogenic differentiation was weakened by the intervention of BSO, but MG132 had no effect. CONCLUSION: ABX exacerbates vascular calcification, possibly by depleting the abundance of Bacteroidetes and SCFAs in the intestine. Supplementation with acetate has the potential to alleviate vascular calcification, which may be an important target for future treatment of vascular calcification.
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Acetatos , Antibacterianos , Ácidos Grasos Volátiles , Microbioma Gastrointestinal , Calcificación Vascular , Animales , Microbioma Gastrointestinal/efectos de los fármacos , Calcificación Vascular/metabolismo , Calcificación Vascular/etiología , Calcificación Vascular/tratamiento farmacológico , Ratones , Ácidos Grasos Volátiles/metabolismo , Acetatos/farmacología , Antibacterianos/efectos adversos , Antibacterianos/farmacología , Masculino , Osteogénesis/efectos de los fármacos , ARN Ribosómico 16S/genética , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Vancomicina/efectos adversos , Vancomicina/farmacología , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/efectos de los fármacosRESUMEN
2,2'-Bipyridyl (bpy) is widely used as a chelating unit for metal complexation but is not usually considered as a hydrogen-bonding unit. This is because the metal-free bpy units are usually in a transoid conformation, and the two nitrogen lone pairs are pointed to the opposite sides. We now report a metallomacrocycle whose three metal-free bpy units are in a cisoid conformation and are fixed in the cavity. The complexation of nickel(II) only at the salen units of the triangular bpytrisalen ligand produced this rigid and planar macrocycle. Its cavity is surrounded by hydrogen-bond acceptors (N of bpy and O of salen), and it was found that unique pentagonal prism clusters of water molecules templated by the cavity were formed in the crystal. This study has not only increased the variation of the synthetic methodologies of multinuclear complexes but has also provided the structural platform on which multiple bpy units exert hydrogen-bonding functions.
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BACKGROUND: Astaxanthin (AST) is a natural compound with anti-inflammatory/immunomodulatory properties that has been found to have probiotic properties. However, the role and mechanism of AST in chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) are still not fully understood. PURPOSE: The aim of this study was to evaluate the effect of AST on CP/CPPS and elucidate the mediating role of the gut microbiota. MATERIALS AND METHODS: An experimental autoimmune prostatitis (EAP) mouse model was utilized to test the potential role of AST on CP/CPPS. Antibiotic cocktail (ABX) treatment and fecal microbiota transplantation (FMT) were used to elucidate the gut microbiota-mediated effects on AST. In addition, 16S rRNA gene sequencing and qRT-PCR analyses were used to analyze changes in the gut microbiota of EAP mice and CP/CPPS patients. Finally, the mechanism by which AST exerts a protective effect on CP/CPPS was explored by untargeted metabolomics and gut barrier function assays. RESULTS: Oral administration of AST reduced prostate inflammation scores, alleviated tactile sensitization of the pelvic region in EAP mice, reduced CD4+ T cell and CD68+ macrophage infiltration in the prostatic interstitium, and inhibited the up-regulation of systemic and localized pain/pro-inflammatory mediators in the prostate. After ABX, the protective effect of AST against CP/CPPS was attenuated, whereas colonization with fecal bacteria from AST-treated EAP mice alleviated CP/CPPS. 16S rRNA gene sequencing and qRT-PCR analyses showed that Akkermansia muciniphila in the feces of EAP mice and CP/CPPS patients showed a trend toward a decrease, which was associated with poor progression of CP/CPPS. In contrast, oral administration of AST increased the relative abundance of A. muciniphila, and oral supplementation with A. muciniphila also alleviated inflammation and pain in EAP mice. Finally, we demonstrated that both AST and A. muciniphila interventions increased serum levels of SCFAs acetate, up-regulated expression of colonic tight junction markers, and decreased serum lipopolysaccharide levels in EAP mice. CONCLUSION: Our results showed that AST improved CP/CPPS by up-regulating A. muciniphila, which provides new potentially effective strategies and ideas for CP/CPPS management.
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Dolor Crónico , Prostatitis , Humanos , Masculino , Ratones , Animales , Prostatitis/tratamiento farmacológico , ARN Ribosómico 16S , Inflamación/tratamiento farmacológico , Dolor Pélvico/tratamiento farmacológico , Dolor Pélvico/metabolismo , Intestinos , Akkermansia , XantófilasRESUMEN
Objective: To compare the safety and effectiveness of robot-assisted partial nephrectomy (RAPN) vs laparoscopic partial nephrectomy (LPN) in the treatment of central renal angiomyolipomas (AMLs). Methods: We retrospectively analyzed the clinical data of 103 patients who were treated with either RAPN or LPN for central AMLs between January 2017 and June 2022. Propensity scores were matched according to sex, age, laterality, body mass index, symptoms, diameter of tumor, location of tumor distribution, R.E.N.A.L score, preoperative hemoglobin, preoperative serum creatinine, preoperative estimated glomerular filtration rate, chronic disease, previous abdominal surgery, preoperative selective arterial embolization, American Society of Anesthesiologists scale, and duration of follow-up, and after matching, perioperative and prognostic data of the two groups were compared. Results: A total of 57 patients underwent RAPN, and 46 patients underwent LPN. Before matching, there were more complex AMLs in the RAPN group, and R.E.N.A.L scores differed between the two groups (10 vs 9, p < 0.001). After matching, the median warm ischemic time in the RAPN group was significantly shorter than that in the LPN group (21.5 minutes vs 28 minutes, p = 0.034), as well as the median time of postoperative mobilization (1 day vs 2 days, p < 0.001). The other indicators were not significantly different between the groups. Conclusions: For central AMLs, both RAPN and LPN were safe and feasible surgical treatments, but RAPN might be associated with shorter warm ischemia time and earlier postoperative mobilization.
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Angiomiolipoma , Neoplasias Renales , Laparoscopía , Procedimientos Quirúrgicos Robotizados , Robótica , Humanos , Angiomiolipoma/cirugía , Puntaje de Propensión , Estudios Retrospectivos , Neoplasias Renales/cirugía , Nefrectomía , Resultado del TratamientoRESUMEN
Outer membrane protein A (OmpA) is the most abundant porin in bacterial outer membranes. KJΔOmpA299-356, an ompA C-terminal in-frame deletion mutant of Stenotrophomonas maltophilia KJ, exhibits pleiotropic defects, including decreased tolerance to menadione (MD)-mediated oxidative stress. Here, we elucidated the underlying mechanism of the decreased MD tolerance mediated by ΔompA299-356. The transcriptomes of wild-type S. maltophilia and the KJΔOmpA299-356 mutant strain were compared, focusing on 27 genes known to be associated with oxidative stress alleviation; however, no significant differences were identified. OmpO was the most downregulated gene in KJΔOmpA299-356. KJΔOmpA299-356 complementation with the chromosomally integrated ompO gene restored MD tolerance to the wild-type level, indicating the role of OmpO in MD tolerance. To further clarify the possible regulatory circuit involved in ompA defects and ompO downregulation, σ factor expression levels were examined based on the transcriptome results. The expression levels of three σ factors were significantly different (downregulated levels of rpoN and upregulated levels of rpoP and rpoE) in KJΔOmpA299-356. Next, the involvement of the three σ factors in the ΔompA299-356-mediated decrease in MD tolerance was evaluated using mutant strains and complementation assays. rpoN downregulation and rpoE upregulation contributed to the ΔompA299-356-mediated decrease in MD tolerance. OmpA C-terminal domain loss induced an envelope stress response. Activated σE decreased rpoN and ompO expression levels, in turn decreasing swimming motility and oxidative stress tolerance. Finally, we revealed both the ΔompA299-356-rpoE-ompO regulatory circuit and rpoE-rpoN cross regulation. IMPORTANCE The cell envelope is a morphological hallmark of Gram-negative bacteria. It consists of an inner membrane, a peptidoglycan layer, and an outer membrane. OmpA, an outer membrane protein, is characterized by an N-terminal ß-barrel domain that is embedded in the outer membrane and a C-terminal globular domain that is suspended in the periplasmic space and connected to the peptidoglycan layer. OmpA is crucial for the maintenance of envelope integrity. Stress resulting from the destruction of envelope integrity is sensed by extracytoplasmic function (ECF) σ factors, which induce responses to various stressors. In this study, we revealed that loss of the OmpA-peptidoglycan (PG) interaction causes peptidoglycan and envelope stress while simultaneously upregulating σP and σE expression levels. The outcomes of σP and σE activation are different and are linked to ß-lactam and oxidative stress tolerance, respectively. These findings establish that outer membrane proteins (OMPs) play a critical role in envelope integrity and stress tolerance.
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Stenotrophomonas maltophilia , Stenotrophomonas maltophilia/genética , Stenotrophomonas maltophilia/metabolismo , Regulón , Peptidoglicano/metabolismo , Factor sigma/metabolismo , Estrés Oxidativo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Regulación Bacteriana de la Expresión GénicaRESUMEN
Akkermansia muciniphila (A. muciniphila) is an anaerobic bacterium that widely colonizes the mucus layer of the human and animal gut. The role of this symbiotic bacterium in host metabolism, inflammation, and cancer immunotherapy has been extensively investigated over the past 20 years. Recently, a growing number of studies have revealed a link between A. muciniphila, and aging and aging-related diseases (ARDs). Research in this area is gradually shifting from correlation analysis to exploration of causal relationships. Here, we systematically reviewed the association of A. muciniphila with aging and ARDs (including vascular degeneration, neurodegenerative diseases, osteoporosis, chronic kidney disease, and type 2 diabetes). Furthermore, we summarize the potential mechanisms of action of A. muciniphila and offer perspectives for future studies.
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BACKGROUND: The response of advanced clear cell renal cell carcinoma (ccRCC) to immunotherapy is still not durable, suggesting that the immune landscape of ccRCC still needs to be refined, especially as some molecules that have synergistic effects with immune checkpoint genes need to be explored. METHODS: The expression levels of CENPM and its relationship with clinicopathological features were explored using the ccRCC dataset from TCGA and GEO databases. Quantitative polymerase chain reaction (qPCR) analysis was performed to validate the expression of CENPM in renal cancer cell lines. Kaplan-Meier analysis, COX regression analysis and Nomogram construction were used to systematically evaluate the prognostic potential of CENPM in ccRCC. Besides, single gene correlation analysis, protein-protein interaction (PPI) network, genetic ontology (GO), kyoto encyclopedia of genes and genomes (KEGG) and gene set enrichment analysis (GSEA) were used to predict the biological behaviour of CENPM and the possible signalling pathways involved. Finally, a comprehensive analysis of the crosstalk between CENPM and immune features in the tumor microenvironment was performed based on the ssGSEA algorithm, the tumor immune dysfunction and exclusion (TIDE) algorithm, the TIMER2.0 database and the TISIDB database. RESULTS: CENPM was significantly upregulated in ccRCC tissues and renal cancer cell lines and was closely associated with poor clinicopathological features and prognosis. Pathway enrichment analysis revealed that CENPM may be involved in the regulation of the cell cycle in ccRCC and may have some crosstalk with the immune microenvironment in tumors. The ssGSEA algorithm, CIBERSOPT algorithm suggests that CENPM is associated with suppressor immune cells in ccRCC such as regulatory T cells. The ssGSEA algorithm, CIBERSOPT algorithm suggests that CENPM is associated with suppressor immune cells in ccRCC such as regulatory T cells. Furthermore, the TISIDB database provides evidence that not only CENPM is positively associated with immune checkpoint genes such as CTLA4, PDCD1, LAG3, TIGIT, but also chemokines and receptors (such as CCL5, CXCL13, CXCR3, CXCR5) may be responsible for the malignant phenotype of CENPM in ccRCC. Meanwhile, predictions based on the TIDE algorithm support that patients with high CENPM expression have a worse response to immunotherapy. CONCLUSIONS: The upregulation of CENPM in ccRCC predicts a poor clinical outcome, and this malignant phenotype may be associated with its exacerbation of the immunosuppressive state in the tumor microenvironment.
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Carcinoma de Células Renales , Carcinoma , Proteínas de Ciclo Celular , Neoplasias Renales , Humanos , Carcinoma de Células Renales/genética , Neoplasias Renales/genética , Activación Transcripcional , Microambiente Tumoral/genética , Regulación hacia Arriba , Proteínas de Ciclo Celular/genéticaRESUMEN
The prognosis for advanced clear cell renal cell carcinoma (ccRCC) is not satisfactory, even though its treatment has evolved rapidly over the past 20 years. Systemic ccRCC treatment options mainly involve antiangiogenic therapy, immune checkpoint blockade, or a combination of these therapies, and as more clinical evidence becomes available, immune checkpoint inhibitors (ICIs) are increasingly dominant. Conventional ICIs lead to the restoration of T-cell activation and a reduction in T-cell depletion by specifically blocking programmed cell death 1 (PD-1), programmed cell death 1 ligand 1 (PD-L1) or cytotoxic T lymphocyte antigen 4 (CTLA-4), ultimately enhancing the antitumor immune response. There is no doubt that these therapies have achieved some clinical efficacy in the overall ccRCC population, but response rates and durability remain a great challenge. Therefore, novel immune checkpoints or new combination therapeutic strategies based on ICIs continue to be sought and developed. This review will provide a comprehensive overview of ICI-based therapeutic strategies in advanced ccRCC, including their mechanisms of action and the latest clinical evidence.
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Carcinoma de Células Renales , Antígeno B7-H1 , Carcinoma de Células Renales/tratamiento farmacológico , Humanos , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Inmunoterapia , Receptor de Muerte Celular Programada 1RESUMEN
AIMS: The emerging of drug resistant Pseudomonas aeruginosa is a critical challenge and renders an urgent action to discover innovative antimicrobial interventions. One of these interventions is to disrupt the pseudomonas quinolone signal (pqs) quorum sensing (QS) system, which governs multiple virulence traits and biofilm formation. This study aimed to investigate the QS inhibitory activity of a series of new PqsR inhibitors bearing a quinoline scaffold against Ps. aeruginosa. METHODS AND RESULTS: The results showed that compound 1 suppressed the expression of QS-related genes and showed the best inhibitory activity to the pqs system of wild-type Ps. aeruginosa PAO1 with an IC50 of 20.22 µmol L-1 . The virulence factors including pyocyanin, total protease, elastase and rhamnolipid were significantly suppressed in a concentration-dependent manner with the compound. In addition, compound 1 in combination with tetracycline inhibited synergistically the bacterial growth and suppressed the biofilm formation of PAO1. The molecular docking studies also suggested that compound 1 could potentially interact with the ligand-binding domain of the Lys-R type transcriptional regulator PqsR as a competitive antagonist. CONCLUSIONS: The quinoline-based derivatives were found to interrupt the quorum sensing system via the pqs pathway and thus the production of virulence factors was inhibited and the antimicrobial susceptibility of Ps. aeruginosa was enhanced. SIGNIFICANCE AND IMPACT OF STUDY: The study showed that the quinoline-based derivatives could be used as an anti-virulence agent for treating Ps. aeruginosa infections.
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Pseudomonas aeruginosa , Piocianina , Antibacterianos/química , Proteínas Bacterianas/metabolismo , Biopelículas , Endopeptidasas/farmacología , Ligandos , Simulación del Acoplamiento Molecular , Elastasa Pancreática/metabolismo , Pseudomonas aeruginosa/metabolismo , Piocianina/metabolismo , Percepción de Quorum , Tetraciclinas/farmacología , Factores de Virulencia/genética , Factores de Virulencia/metabolismoRESUMEN
Background: The aim of this study was to identify novel genetic features of Hunner's lesion interstitial cystitis (HIC) via comprehensive analysis of the Gene Expression Omnibus (GEO) database. Methods: The GSE11783 and GSE28242 datasets were downloaded from GEO for further analysis. Differentially expressed genes (DEGs) were identified and analyzed for functional annotation. The diagnostic markers for HIC were screened and validated using the least absolute shrinkage and selection operator (LASSO) logistic regression and support vector machine recursive feature elimination (SVM-RFE) algorithms. Finally, the cell-type identification by estimating relative subsets of RNA transcripts (CIBERSORT) algorithm was adopted to investigate the correlation between immune cell infiltration and diagnostic markers in HIC. Results: A total of 7837 DEGs were identified in GSE11783 and 1583 DEGs in GSE28242. Venn diagrams were used to obtain 16 overlapping upregulated and 67 overlapping downregulated DEGs separately. The LASSO logistic model and SVM-RFE algorithm were used to identify 6 genes including KRT20, SLFN11, CD86, ITGA4, PLAC8, and BTN3A3 from DEGs as diagnostic markers for HIC. Their diagnostic potential in HIC and bladder pain syndrome/interstitial cystitis (BPS/IC) were acceptable. PLAC8 exhibited the best diagnostic performance in BPS/IC with an area under the curve of 0.916. The results of immune infiltration involving GSE11783 revealed that the plasma cell ratio (p = 0.017), activated memory CD4+ T cells (p = 0.009), activated dendritic cells (p = 0.01), eosinophils (p = 0.004), and neutrophils (p = 0.03) were significantly higher in HIC than in normal samples, in contrast to resting mast cells (p = 0.022). A positive correlation existed between diagnostic markers and infiltrating immune cells. Conclusion: KRT20, SLFN11, CD86, ITGA4, PLAC8, and BTN3A3 represent novel and potent diagnostic markers for HIC. They also exhibit certain diagnostic potential in BPS/IC. Immune cell infiltration might play a key role in the pathogenesis and progression of BPS/IC.
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Pathogenic bacteria experience diverse stresses induced by host cells during infection and have developed intricate systems to trigger appropriate responses. Bacterial stress responses have been reported to defend against these stresses and cross-protect bacteria from antibiotic attack. In this study, we aimed to assess whether oxidative stress affects bacterial susceptibility to fluoroquinolone (FQ) and the underlying mechanism. Stenotrophomonas maltophilia, a species with high genetic diversity, is distributed ubiquitously and is an emerging multidrug-resistant opportunistic pathogen. FQs are among the limited antibiotic treatment options for S. maltophilia infection. The minimum inhibitory concentrations (MICs) of 103 S. maltophilia clinical isolates against ciprofloxacin (CIP) and levofloxacin (LVX) were determined using the agar dilution method in Mueller-Hinton plates with or without menadione (MD), a superoxide generator. The resistance rates for ciprofloxacin and levofloxacin were 40% and 18% in the MD-null group and increased to 91% and 23%, respectively, in the MD-treated group. Of the 103 isolates tested, 54% and 27% had elevated MICs against ciprofloxacin and levofloxacin, respectively, in the presence of MD. The involvement of oxidative stress responses in the MD-mediated FQ resistance was further assessed by mutants construction and viability assay. Among the 16 oxidative stress alleviation systems evaluated, fadACB and smeU1VWU2X contributed to MD-mediated FQ resistance. The antibiotic susceptibility test is an accredited clinical method to evaluate bacterial susceptibility to antibiotics in clinical practice. However, oxidative stress-mediated antibiotic resistance was not detected using this test, which may lead to treatment failure.
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Infecciones por Bacterias Gramnegativas , Stenotrophomonas maltophilia , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Ciprofloxacina/farmacología , Ciprofloxacina/uso terapéutico , Fluoroquinolonas/farmacología , Fluoroquinolonas/uso terapéutico , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Humanos , Levofloxacino/farmacología , Levofloxacino/uso terapéutico , Pruebas de Sensibilidad Microbiana , Estrés OxidativoRESUMEN
Gonadotropin-releasing hormone (GnRH) receptor agonists are still the most commonly used androgen deprivation treatment (ADT) drugs for prostate cancer in clinical practice. Currently, the GnRH receptor antagonists used for endocrine therapy for prostate cancer primarily include degarelix and relugolix (TAK-385). The former is administered by subcutaneous injection, while the latter is an oral drug. Compared to GnRH agonists, GnRH antagonists reduce serum testosterone levels more rapidly without an initial testosterone surge or subsequent microsurges. This review focuses on the mechanism of action of GnRH antagonists and agonists, the developmental history of GnRH antagonists, and emerging data from clinical studies of the two antagonists used as endocrine therapy for prostate cancer.
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Antagonistas de Andrógenos/farmacología , Antineoplásicos/farmacología , Oligopéptidos/farmacología , Compuestos de Fenilurea/farmacología , Neoplasias de la Próstata/tratamiento farmacológico , Pirimidinonas/farmacología , Receptores LHRH/antagonistas & inhibidores , Humanos , Masculino , Neoplasias de la Próstata/metabolismo , Receptores LHRH/metabolismoRESUMEN
BACKGROUND: To evaluate the feasibility and safety of robot-assisted retroperitoneal laparoscopic adrenalectomy (RARLA) for large pheochromocytomas (PHEOs; size≥6 cm) compared with retroperitoneal laparoscopic adrenalectomy (RLA). METHODS: Fifty-one patients who underwent adrenalectomy for large PHEOs between March 2016 and January 2019 were enrolled and divided into two groups, including 32 RLA cases and 19 RARLA cases. We compared the perioperative efficacy and long-term follow-up results between the two groups. RESULTS: Preoperative data, including demographics, comorbidities and tumour characteristics, were similar between the groups. Intraoperatively, the RARLA group had a lower incidence of haemodynamic instability (26.3% vs. 56.2%, P = 0.038) and less intraoperative blood loss (100 ml vs. Two hundred milliliter, P = 0.042) than the RLA group. The groups showed no significant differences in operative time or transfusion rates. Postoperatively, the time to diet resumption, time to ambulation, time to drainage removal and postoperative hospital stay were shorter in the RARLA group than in the RLA group (1 d vs. 2 d, P = 0.027; 1 d vs. 2 d, P = 0.034; 3 d vs. 5 d, P = 0.002; 5 d vs. 6 d, P = 0.02, respectively). The groups exhibited no significant differences in the duration of anaesthetic use, complications, or long-term follow-up results for the blood pressure (BP) improvement rate. CONCLUSIONS: Compared with RLA, RARLA is a safe, feasible and even optimized procedure for large PHEOs.
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Neoplasias de las Glándulas Suprarrenales , Adrenalectomía , Laparoscopía , Feocromocitoma , Procedimientos Quirúrgicos Robotizados , Neoplasias de las Glándulas Suprarrenales/cirugía , Adrenalectomía/métodos , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Feocromocitoma/cirugía , Estudios RetrospectivosRESUMEN
To investigate the traditional village living environment adaptability to desertification and topography, the suitability evaluation index system and weight of traditional Buyei traditional villages in the rocky desertification area human settlement were quantified using Delphi method and comprehensive weighting method. We calculated human settlements environment suitability value and threshold to comprehensively analyze the human settlements environment suitability. The results showed that 10% of the traditional Buyei traditional villages were located in the rocky desertification areas with high intensity and extremely high intensity and had the tradition of selecting the best environment. The index system of residential environment suitability was composed of five first-level indices (economy, historic culture, ecology, society, and building environment suitability) and 26 second-level indices. This index system was applicable to villages in karst regions. The comprehensive environmental suitability value (2.81-3.77), the economy value (0.77-1.17), the historic culture value (0.39-0.50), the ecology value (0.83-1.07), the social environment value (0.38-0.53) all decreased with the increasing intensity of rocky desertification, but the suitability value of building environment did not change, which ranged from 0.43 to 0.51. Rocky desertification had profound and synergistic impacts on economy, historic culture, ecology and social environment. The floor level of the human settlement suitability threshold was 2.93. If the threshold was lower than 2.93, it could be considered to move or take measures to improve its value. The suitability value (3.56) of traditional village living environment in mountain slope was higher than that in depression (3.42) and valley (3.16). The human settlement suitability of traditional villages in rocky desertification area was higher than that of ordinary villages, but was lower than that of normal landform, with the differences in economy and ecology being the main reasons. To improve the living environment of traditional villages in rocky desertification areas, we should strengthen the comprehensive control of rocky desertification and policy support, develop ecological economy and tourism, protect historic culture or choose ecological migration. This research could provide theoretical base for the planning and construction of village living environment protection in karst areas.
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Conservación de los Recursos Naturales , Ecosistema , China , Sequías , Ecología , HumanosRESUMEN
Mesoporous activated carbons with high surface area were prepared from three waste polymers, i. e., tire rubber, polyvinyl chloride (PVC) and polyethyleneterephtalate (PET), by KOH activation. The adsorption/desorption characteristics of dyes (methylene blue and methyl orange) on the carbons were studied. The effects of pH, ionic strength and surface surfactants in the solution on the dye adsorption were also investigated. The results indicated that the carbons derived from PVC and PET exhibited high surface area of 2 666 and 2 831 m2 x g(-1). Their mesopore volume were as high as 1.06 and 1.30 cm3 g(-1), respectively. 98.5% and 97.0% of methylene blue and methyl orange were removed in 15 min by PVC carbon, and that of 99.5% and 95.0% for PET carbon. The Langmuir maximum adsorption capacity to these dyes was more than 2 mmol x g(-1), much higher than that of commercial activated carbon F400. Compared with Freundlich model, the adsorption data was fitted better by Langmiur model, indicating monolayer coverage on the carbons. The adsorption was highly dependent on solution pH, ionic strength and concentration of surface surfactants. The activated carbons exhibited higher adsorption to methylene blue than that of methyl orange, and it was very hard for both of the dyes to be desorbed. The observation in this study demonstrated that activated carbons derived from polymer waste could be effective adsorbents for the treatment of wastewater with dyes.
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Carbón Orgánico/química , Colorantes/aislamiento & purificación , Polímeros/química , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/aislamiento & purificación , Adsorción , Colorantes/química , Residuos Industriales/prevención & controlRESUMEN
We report herein a fluoroionophore sensor derivated from tryptophan that shows high sensitivity (detection limit up to 0.15 microM) and specific selectivity for lead ion (Pb2+) over Ca2+, Cd2+, Co2+, Cr3+, Cu2+, K+, Mg2+, Na+, Fe2+, Mn2+, Ni2+ and Zn2+ in aqueous solution.