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1.
J Vasc Surg ; 78(6): 1369-1375, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37390850

RESUMEN

OBJECTIVE/BACKGROUND: Endovascular thoracoabdominal and pararenal aortic aneurysm repair is more complex and requires more devices than infrarenal aneurysm repair. It is unclear if current reimbursement covers the cost of delivering this more advanced form of vascular care. The objective of this study was to evaluate the economics of fenestrated-branched (FB-EVAR) physician-modified endograft (PMEG) repairs. METHODS: We obtained technical and professional cost and revenue data for four consecutive fiscal years (July 1, 2017, to June 30, 2021) at our quaternary referral institution. Inclusion criteria were patients who underwent PMEG FB-EVAR in a uniform fashion by a single surgeon for thoracoabdominal/pararenal aortic aneurysms. Patients in industry-sponsored clinical trials or receiving Cook Zenith Fenestrated grafts were excluded. Financial data were analyzed for the index operation. Technical costs were divided into direct costs that included devices and billable supplies and indirect costs including overhead. RESULTS: 62 patients (79% male, mean age: 74 years, 66% thoracoabdominal aneurysms) met inclusion criteria. The mean aneurysm size was 6.0 cm, the mean total operating time was 219 minutes, and the median hospital length of stay was 2 days. PMEGs were created with a mean number of 3.7 fenestrations, using a mean of 8.6 implantable devices per case. The average technical cost per case was $71,198, and the average technical reimbursement was $57,642, providing a net negative technical margin of $13,556 per case. Of this cohort, 31 patients (50%) were insured by Medicare remunerated under diagnosis-related group code 268/269. Their respective average technical reimbursement was $41,293, with a mean negative margin of $22,989 per case, with similar findings for professional costs. The primary driver of technical cost was implantable devices, accounting for 77% of total technical cost per case over the study period. The total operating margin, including technical and professional cost and revenue, for the cohort during the study period was negative $1,560,422. CONCLUSIONS: PMEG FB-EVAR for pararenal/thoracoabdominal aortic aneurysms produces a substantially negative operating margin for the index operation driven largely by device costs. Device cost alone already exceeds total technical revenue and presents an opportunity for cost reduction. In addition, increased reimbursement for FB-EVAR, especially among Medicare beneficiaries, will be important to facilitate patient access to such innovative technology.


Asunto(s)
Aneurisma de la Aorta Toracoabdominal , Procedimientos Endovasculares , Cirujanos , Estados Unidos , Humanos , Anciano , Masculino , Femenino , Estrés Financiero , Medicare , Procedimientos Endovasculares/efectos adversos
2.
J Cardiothorac Vasc Anesth ; 37(12): 2524-2530, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37716892

RESUMEN

OBJECTIVES: Stroke after thoracic aortic surgery is a complication that is associated with poor outcomes. The aim is to characterize the intraoperative risk factors for stroke development. DESIGN: A retrospective analysis. SETTING: Tertiary, high-volume cardiac surgery center. PARTICIPANTS: Patients who had surgical repair of thoracic aortic diseases from January 1, 2017, through December 31, 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 704 patients were included, of whom 533 had ascending aortic aneurysms, and 171 had type A aortic dissection. The incidence of postoperative stroke was 4.5% (95% CI 2.9%-6.6%) for ascending aortic aneurysms compared with 12.3% (95% CI 7.8%-18.16%) in type-A aortic dissections. Patients who developed postoperative strokes had significantly lower intraoperative hemoglobin median (7.5 gm/dL [IQR 6.8-8.6] v 8.55 gm/dL [IQR 7.3-10.0]; p < 0.001). The median cardiopulmonary bypass time was 185 minutes (IQR 136-328) in the stroke group versus 156 minutes (IQR 113-206) in the nonstroke group (p = 0.014). Circulatory arrest was used in 57.8% versus 38.5% of the nonstroke patients (p = 0.017). The initial temperature after leaving the operating room was lower, with a median of 35.0°C (IQR 34-35.92) in the stroke group versus 35.5°C (IQR 35-36) in the nonstroke cohort (p = 0.021). CONCLUSIONS: This single-center study highlighted the potential importance of intra-operative factors in preventing stroke. Lower hemoglobin, longer duration of cardiopulmonary bypass, deep hypothermic circulatory arrest, and postoperative hypothermia are potential risk factors for postoperative stroke. Further studies are needed to prevent this significant complication in patients with thoracic aortic diseases.


Asunto(s)
Aneurisma de la Aorta Torácica , Aneurisma de la Aorta , Enfermedades de la Aorta , Disección Aórtica , Procedimientos Quirúrgicos Cardíacos , Accidente Cerebrovascular , Humanos , Estudios Retrospectivos , Aorta Torácica/cirugía , Accidente Cerebrovascular/epidemiología , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/prevención & control , Factores de Riesgo , Aneurisma de la Aorta/cirugía , Disección Aórtica/epidemiología , Disección Aórtica/cirugía , Enfermedades de la Aorta/cirugía , Enfermedades de la Aorta/etiología , Hemoglobinas , Aneurisma de la Aorta Torácica/cirugía , Paro Circulatorio Inducido por Hipotermia Profunda/efectos adversos , Resultado del Tratamiento
3.
J Vasc Surg ; 75(1): 118-125.e1, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34302934

RESUMEN

OBJECTIVE: Sex-based disparities in surgical outcomes have emerged as an important focus in contemporary healthcare delivery. Likewise, the appropriate usage of endovascular abdominal aortic aneurysm repair (EVAR) in the United States remains a subject of ongoing controversy, with a significant number of U.S. EVARs failing to adhere to the Society for Vascular Surgery (SVS) clinical practice guideline (CPG) diameter thresholds. The purpose of the present study was to determine the effect of sex among patients undergoing EVAR that was not compliant with the SVS CPGs. METHODS: All elective EVAR procedures for abdominal aortic aneurysms without a concomitant iliac aneurysm (≥3.0 cm) in the SVS Vascular Quality Initiative were analyzed (2015-2019; n = 25,112). SVS CPG noncompliant repairs were defined as a size of <5.5 cm for men and <5.0 cm for women. The primary endpoint was 30-day mortality. The secondary endpoints were all-cause mortality, complications, and reintervention. Logistic regression was performed to control for surgeon- and patient-level factors. Freedom from the endpoints was determined using the Kaplan-Meier method. RESULTS: Noncompliant EVAR was performed in 9675 patients (38.5%). Although men were significantly more likely to undergo such procedures (90% vs 10%; odds ratio [OR], 3.1; 95% confidence interval [CI], 2.9-3.4; P < .0001), the 30-day mortality was greater for the women than the men (1.8% vs 0.5%; P = .0003). Women also experienced significantly higher rates of multiple complications, including postoperative myocardial infarction (1% vs 0.3%; P = .006), respiratory failure (1.4% vs 0.6%; P = .01), intestinal ischemia (0.7% vs 0.2%; P = .003), access vessel hematoma (3% vs 1.2%; P = .0006), and iliac access vessel injury (2.4% vs 0.8%; P < .0001). Additionally, women experienced increased overall 1-year reintervention rates (11.5% vs 5.8%; P < .0001). In the adjusted analysis, 30-day mortality and any in-hospital complication risk remained significantly greater for the women (30-day death: OR, 3.1; 95% CI, 1.6-5.8; P = .0005; in-hospital complication: OR, 1.9; 95% CI, 1.4-2.6; P < .0001). Women also experienced increased reintervention rates over time compared with men (OR, 1.5; 95% CI, 1.1-2.2; P = .02). CONCLUSIONS: Although men were more likely to undergo non-CPG compliant EVAR, women experienced increased short-term morbidity and 30-day mortality and higher rates of reintervention when undergoing non-CPG compliant EVAR. These unanticipated findings necessitate increased scrutiny of current U.S. sex-based EVAR practice and should caution against the use of non-CPG compliant EVAR for women.


Asunto(s)
Aneurisma de la Aorta Abdominal/cirugía , Implantación de Prótesis Vascular/estadística & datos numéricos , Procedimientos Quirúrgicos Electivos/estadística & datos numéricos , Adhesión a Directriz/estadística & datos numéricos , Complicaciones Posoperatorias/epidemiología , Factores de Edad , Anciano , Anciano de 80 o más Años , Aneurisma de la Aorta Abdominal/diagnóstico , Aneurisma de la Aorta Abdominal/mortalidad , Implantación de Prótesis Vascular/efectos adversos , Implantación de Prótesis Vascular/normas , Procedimientos Quirúrgicos Electivos/normas , Femenino , Mortalidad Hospitalaria , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Guías de Práctica Clínica como Asunto , Estudios Prospectivos , Sistema de Registros/estadística & datos numéricos , Reoperación/estadística & datos numéricos , Estudios Retrospectivos , Medición de Riesgo/estadística & datos numéricos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores Sexuales , Sociedades Médicas/normas , Factores de Tiempo , Resultado del Tratamiento , Estados Unidos/epidemiología
4.
JOM (1989) ; 74(3): 1020-1026, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35039739

RESUMEN

The fast depletion of critical metals in natural reserves against their increasing demands in advanced technology application presents the necessity to exploit the end-of-life/waste materials as unconventional resources. Due to a higher accumulation of platinum-group metals (PGMs) in exhausted autocatalytic converters, their recycling through an integrative bio-solvo-chemical technique has been studied. PGMs were efficiently dissolved in bio-cyanide solution produced by Chromobacterium violaceum. The autoclave leaching was optimized in the conditions of temperature, 150°C; pO2, 200 psi; and time, 120 min, yielding > 90% PGMs' dissolution. PGMs' separation from cyanide leach liquor was performed using an ionic liquid, Cyphos IL101. Under optimum conditions (i.e., ionic liquid concentration, 0.15 mol/L; extraction pH, 10.4; and temperature, 25°C), Pt and Pd were selectively stripping with > 99% efficiency in 0.1 mol/L (acidic) thiourea and 1.0 mol/L HNO3 solution, respectively, leaving Rh in the raffinate.

5.
J Environ Manage ; 291: 112748, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33971514

RESUMEN

Bimetallic (Ag-Pd/α-Al2O3) catalysts are essentially applied to naptha-cracking process with a controlled CO2 emission. After losing the catalytic properties in long run, the landfilling disposal of spent catalysts poses severe stress to the environment and deprivation of precious metals. Therefore, an innovative solvo-chemical recycling approach that involving the solid-liquid and liquid-liquid mass transfer phenomena was studied. The parametric variations for dissolving precious metals yielded >98% efficiency at a lixiviant concentration, 2.0 mol L-1 HCl; pulp density, 20% (wt./vol.); agitation speed, 300 rpm, temperature, 90 °C, and duration, 60 min. The activation energy of silver (6.9 kJ mol-1) and palladium (11.9 kJ mol-1) leaching indicated that the process was governed by a diffusion-controlled mechanism. Subsequently, silver and palladium were separated using 0.15 mol L-1 LIX 84-I at different acid concentration that yielding the maximum separation factor (ß(Ag/Pd) = 12,501) at 2.0 mol L-1 HCl. Stripping of separately (Ag/Pd)-loaded organic solutions with different solutions of HNO3, (NH4)2SO4, and CH4N2S showed higher affinity for thiourea, yielding 56%, 38%, and 87% efficiency, respectively. Thus the counter-current extraction at an organic-to-aqueous (O:A) ratio of 1:2.5 and stripping with 0.5 mol L-1 CH4N2S at an O:A ratio of 2:1 yielded a five-fold enrich solutions of precious metals (75.2 mg L-1 Ag and 188.5 mg L-1 Pd) with a purity of >99.9%. The process essentially aims to Goal 12 under the United Nations' Sustainable Development Goals for sustainable recycling of industrial wastes consequently conserving the natural mineral reserves.


Asunto(s)
Residuos Electrónicos , Plata , Catálisis , Residuos Electrónicos/análisis , Residuos Industriales , Paladio , Reciclaje
6.
Ann Surg Oncol ; 26(6): 1622-1628, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30761439

RESUMEN

BACKGROUND: Despite burgeoning interest in Complex General Surgical Oncology (CGSO) fellowship training, little is reported about postgraduate employment. The goal of this study was to characterize CGSO graduates' first employment and to identify factors that influenced this decision. METHODS: The National Cancer Institute (NCI) and Society of Surgical Oncology developed and distributed an electronic survey to CGSO fellows who graduated from 2005 to 2016. RESULTS: The survey response rate was 47% (237/509). Fifty-seven percent of respondents were first employed as faculty surgeons at a university-based/affiliated hospital, with 15% returning to their residency institution. The distribution of respondents' current employment across the United States mirrored the locations of their hometowns. Eighty-five percent of respondents care for patients across at least three disease types, most commonly hepatopancreatobiliary (81%), esophagus/gastric (75%), and sarcoma (74%). Twenty-seven percent of respondents spend the majority of their time in one area of surgical oncology; melanoma, breast, and head/neck were the most common. Two-thirds of respondents (67%) reported that they performed either clinical or basic science research as part of their current position. Multiple factors influenced the decision of first faculty position. CONCLUSIONS: Most CGSO graduates are employed at academic medical centers across the country in proximity to NCI-designated centers, treat a variety of disease types, and spend a percentage of their time dedicated to clinical research.


Asunto(s)
Selección de Profesión , Competencia Clínica , Becas/estadística & datos numéricos , Internado y Residencia/estadística & datos numéricos , Neoplasias/cirugía , Oncología Quirúrgica/educación , Adulto , Empleo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cirujanos , Encuestas y Cuestionarios , Factores de Tiempo
7.
Pediatr Transplant ; 23(7): e13566, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31407858

RESUMEN

Renal transplantation is the treatment of choice for ESRD in children. It is associated with better quality of life, growth of children, and improved long-term survival. The aim of the study was to evaluate the outcomes of pediatric renal transplantation at a tertiary care center in UAE. A retrospective chart review was undertaken for all the pediatric renal transplants performed at Sheikh Khalifa Medical City, Abu Dhabi, UAE, over the past 9 years. The study evaluated the demographic data, outcomes, and complications of pediatric renal transplantation. The post-transplantation outcomes including surgical complications, documented infections, graft rejection, graft and patient survival, effect on growth, and eGFR were reviewed. Between 2010 and 2018, 30 pediatric patients underwent renal transplantation. The follow-up period ranged from 1 to 9 years with a mean of 3.3 years. The mean age of the patients at the time of transplant was 9.8 years, and 56.7% were males. Prior to the transplantation, the majority of the recipients were on peritoneal dialysis (70.0%). Main source of renal donation at our center was from LRD, chiefly from parents. Patient survival at 1 and 5 years was 100% and 96.7%, respectively. Graft survival at 1 and 5 years was 96.7% and 83.3%, respectively. During the 9-year follow-up period, 5 (16.7%) recipients experienced rejection episode. This study demonstrates that during 5-year period, pediatric kidney transplantation program has achieved optimal patient (96.7%) and graft (83.3%) survival rates and is comparable to well-established centers.


Asunto(s)
Fallo Renal Crónico/cirugía , Trasplante de Riñón , Adolescente , Niño , Preescolar , Femenino , Tasa de Filtración Glomerular , Rechazo de Injerto , Supervivencia de Injerto , Humanos , Donadores Vivos , Masculino , Desarrollo de Programa , Calidad de Vida , Estudios Retrospectivos , Resultado del Tratamiento , Emiratos Árabes Unidos/epidemiología
8.
J Paediatr Child Health ; 55(10): 1237-1240, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-30714243

RESUMEN

AIM: Atypical haemolytic uraemic syndrome (aHUS) is a debilitating condition that can cause significant morbidity and mortality in children if not adequately and promptly treated. This report shares real-world data on the use of eculizumab in children with aHUS. METHODS: We report our experience with the use of eculizumab in 14 children with aHUS. RESULTS: The median age at aHUS diagnosis was 12 months (range: 2-108 months), with six (42.9%) patients presenting in infancy and six (42.9%) being males. Eculizumab therapy was associated with haematological and thrombotic microangiopathy responses in 14 (100%) and 13 (92.9%) patients after a median of 9 days (range: 7-12 days) and 9.5 days (range: 7-14 days), respectively. None of the six patients who were previously treated with plasma therapy required any further infusions. Of the six patients who previously required dialysis, only one patient continued to do so and eventually received a renal transplant. The median time to ≥25% decrease in serum creatinine level in the remaining patients was 16 days (range: 14-21 days), and estimated glomerular filtration rate increased from a median of 17-101 mL/min/1.73 m2 . The safety profile was similar to that reported in the literature, and 10 patients continue to receive therapy, with 3 being on the drug for 4 or more years. CONCLUSION: Our study adds to the growing body of evidence highlighting the efficacy and safety of eculizumab for the management of children with aHUS.


Asunto(s)
Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales Humanizados/farmacología , Síndrome Hemolítico Urémico Atípico/tratamiento farmacológico , Inactivadores del Complemento/administración & dosificación , Inactivadores del Complemento/farmacología , Evaluación de Resultado en la Atención de Salud , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Emiratos Árabes Unidos
10.
Water Sci Technol ; 78(1-2): 147-155, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30101797

RESUMEN

In the present study, biosorption behavior of a green filamentous alga, spirogyra in its native and modified states was investigated for copper removal from an electroplating industrial effluent. For this, the effluent containing 194 mg·L-1 Cu2+ in sulfate medium was contacted with both forms of spirogyra, under the parametric variations of effluent pH, adsorbent dosage, contact time, and sorption temperature. The study revealed spirogyra as a prominent candidate for removing contaminant metal cation; however, at the same condition, biosorption capacity of modified biomass in gel form was higher than the native spirogyra. At the optimized condition with 6 g sorbent dosage treated to 100 mL effluent for 30 min at pH 6.0 and temperature 20 °C, the maximum 82.8% and 96.4% copper could be adsorbed by the native and modified spirogyra, respectively. The batch sorption data using native biomass followed pseudo-first-order kinetic; exhibiting the multilayer sorption mechanism via surface diffusion could be defined by the Freundlich model. In contrast, the sulfuric acid treated modified spirogyra followed pseudo-second-order kinetics and intra particle diffusion as the rate-limiting step.


Asunto(s)
Cobre , Galvanoplastia , Residuos Industriales/análisis , Spirogyra/metabolismo , Adsorción , Biodegradación Ambiental , Biomasa , Cobre/aislamiento & purificación , Cobre/metabolismo , Cinética , Temperatura
11.
J Immunol ; 195(11): 5117-22, 2015 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-26589749

RESUMEN

Cancer immunotherapy is a rapidly evolving field that exploits T cell responses to tumor-associated Ags to induce tumor rejection. Molecular identification of tumor rejection Ags has helped define several classes of Ags, including tissue differentiation and tumor germline Ags. The ability to genetically engineer Ag-specific receptors into T cells provides an opportunity to translate these findings into therapies. New immunotherapy agents, notably checkpoint inhibitors, have demonstrated unprecedented efficacy in certain cancers. However, the nature of the Ags driving those beneficial immune responses remains unclear. New evidence suggests that tumors express immunogenic, tumor-specific epitopes generated from the same mutations that drive cancer development. Correlations between cancer types responding to immunotherapies and the frequency of somatic mutations may clarify what drives natural antitumor immune responses. This fusion of tumor immunology and genetics is leading to new ways to target this class of ideal tumor-specific Ags and could allow the application of immunotherapy to many cancers.


Asunto(s)
Traslado Adoptivo/métodos , Antígenos de Neoplasias/inmunología , Neoplasias/terapia , Receptores de Antígenos de Linfocitos T/genética , Linfocitos T/inmunología , Antígenos de Diferenciación/genética , Antígenos de Diferenciación/inmunología , Antígenos de Neoplasias/genética , Epítopos de Linfocito T/inmunología , Humanos , Neoplasias/inmunología , Receptores de Antígenos de Linfocitos T/inmunología
12.
Waste Manag ; 174: 187-202, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38056367

RESUMEN

With the rapid deployment of renewable energy using photovoltaic (PV) panels, the sustainable management of decommissioned PV modules has become challenging. Decommissioned modules contain heavy metals, such as copper, cadmium, and lead, and hazardous polymer substances, such as ethylene vinyl acetate, polyethylene terephthalate, and polyvinylidene fluoride, which can pose a serious threat to the environment if disposed in a landfill. In addition, the low concentration value of critical metals, such as silver, indium, and tellurium, can also be lost. In this context, recycling decommissioned PV panels can be useful to resource recovery of valuable metals while lowering environmental stress. However, the lower share of PV modules and the prolonged life of 25-30 years compared to other waste volumes (e.g., electronic waste) hinder the progress in this direction. In contrast, reaching the end-of-life of the deployed first-generation PV panels is creating attraction toward the recycling of decommissioned modules. Henceforth, exploring the commercial viability of PV recycling necessitates a review of the methodologies that have been investigated on a laboratory scale and have the potential to be up-scaled. In this review, the recent trends in various PV-recycling steps, including frame disassembly, delamination, metal extraction, and recovery, are underlined while the associated problems are determined to suggest the required improvements in future technology. Furthermore, the environmental and economic feasibility of a few techniques are discussed to establish the viability of the recycling process. This review contributes to formulating PV waste management strategies and providing future research directions.


Asunto(s)
Residuos Electrónicos , Administración de Residuos , Reciclaje/métodos , Administración de Residuos/métodos , Cobre , Plata , Indio , Sustancias Peligrosas , Residuos Electrónicos/análisis
13.
Sci Total Environ ; 929: 172657, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38649041

RESUMEN

The incineration fly ash (IFA) resulting from municipal solid waste combustion is laden with heavy metals, necessitating proper treatment not only for environmental management but also to reclaim the metal values. The surge in non-traditional metals like cobalt as emerging contaminant within IFA samples further attracts to address this issue. In response, the hydrometallurgical recycling of a cobalt-bearing IFA has been studied. Thereby, approximately 98 % zinc and 96 % cobalt were leached using a 1.0 mol/L H2SO4 solution at 90 °C and 1 h of leaching time. In-depth analysis of the leaching process unveiled metals' dissolution primarily via the ion-exclusion mechanism, as evidenced by lower diffusion coefficients (between 10-9 and 10-11 m2/s) and activation energies (9.6-14.9 kJ/mol). Above 99 % separation of zinc from the cobalt-bearing leach liquor was achieved by extraction with 1.0 mol/L D2EHPA at an equilibrium pH below 3.0, followed by stripping with a 2.0 mol/L H2SO4 solution. Cobalt, remained in the raffinate was efficiently precipitated by adding a 20 % excess dosage of oxalic acid to the stoichiometric ratio of C2O42-:Co2+, resulting in only 5 mg/L cobalt left in the solution when precipitation occurred at a pH of 2.8. Additionally, the conversion of CoC2O4 to high-purity Co3O4 was conducted through heat-treatment at 600 °C. The resulting Co3O4 was mixed with Li2CO3 at a Li/Co molar ratio of 1.1, yielding a LiCoO2 precursor that exhibited good electrochemical properties with a capacity of 128 mAh/g, thus affirming the high quality of the recycled cobalt. A comprehensive life-cycle assessment of the recycling process revealed that cobalt precipitation alone contributes approximately 50 % of the total global warming potential (GWP = 4.2624 kg CO2-eq). Notably, this value is remarkably lower than the GWP reported for primary cobalt production, highlighting the environmentally-friendly approach of this recycling endeavor.

16.
Bioprocess Biosyst Eng ; 35(3): 433-40, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21947702

RESUMEN

Present work describes the bioleaching potential of metals from low-grade mining ore containing smithsonite, sphaerocobaltite, azurite and talc as main gangue minerals with adapted consortium of Sulfobacillus thermosulfidooxidans strain-RDB and Thermoplasma acidophilum. Bioleaching potential improved markedly by added energy source, acid preleaching and adaptation of microbial consortium with mixed metal ions. During whole leaching period including acid preleaching stage of 960 h and bioleaching stage of 212 days about 76% Co, 70% Zn, 84% Cu, 72% Ni and 63% Fe leached out.


Asunto(s)
Bacilos Grampositivos Formadores de Endosporas/crecimiento & desarrollo , Metales/química , Minería , Talco/química , Thermoplasma/crecimiento & desarrollo , Bacilos Grampositivos Formadores de Endosporas/metabolismo , Metales/metabolismo , Thermoplasma/metabolismo
17.
Semin Vasc Surg ; 35(2): 210-218, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35672111

RESUMEN

The incidence of peripheral artery disease continues to rise worldwide, with a concomitant rise in the subset of patients who manifest with chronic limb-threatening ischemia (CLTI). A mainstay of CLTI treatment is revascularization through open surgical bypass, endovascular therapy, or hybrid approaches combining the two modalities. However, a significant proportion of these patients are considered to have nonreconstructable, or no-option, CLTI. This is related to either significant pedal arterial occlusive disease or lack of a bypass conduit. Deep vein arterialization has been used as a potential treatment option for this cohort of patients. We explore the various described methodologies of deep vein arterialization, including open, hybrid, and totally percutaneous. These studies suggest that deep vein arterialization is a promising treatment paradigm for patients with no-option CLTI, with encouraging results in terms of technical feasibility, wound healing, and ultimately limb salvage. However, further study of appropriate patient selection, standardization of techniques, and long-term follow-up are needed.


Asunto(s)
Procedimientos Endovasculares , Enfermedad Arterial Periférica , Amputación Quirúrgica , Enfermedad Crónica , Isquemia Crónica que Amenaza las Extremidades , Procedimientos Endovasculares/efectos adversos , Humanos , Isquemia/diagnóstico por imagen , Isquemia/cirugía , Recuperación del Miembro , Enfermedad Arterial Periférica/diagnóstico por imagen , Enfermedad Arterial Periférica/cirugía , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento
18.
Chemosphere ; 286(Pt 3): 131978, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34426287

RESUMEN

The present study dealt with the restricted microbial tolerance for lead and tin during bioleaching of waste printed circuit boards (WPCBs) and lower extraction yields of valuable metals. Pretreatment of WPCBs in 4.0 mol/L HNO3 at 90 °C for 180 min duration prominently dissolved the toxicant metals before the microbial mobilization of valuable metals. Acid pretreatment followed the first-order kinetics that exhibiting an intermediate-controlled mechanism with the apparent activation energy determined to be Ea(Pb), 25.1 kJ/mol and Ea(Sn), 21.9 kJ/mol. Thereafter, the parametric optimization of aeration rate, O2-enrichment, external CO2 supply, temperature, and time for bioleaching of ground WPCBs was examined using Sulfobacillus thermosulfidooxidans (strain RDB). A favourable condition for Cu-bioleaching under higher oxidative environment in comparison to Ni and Zn exhibited the auto-catalytic behaviour of Cu2+ in the biological system. More than 92% of valuable metals were extracted under the optimal condition of aeration rate, 0.5 L/min; O2-enrichement dosage, 30%; external CO2 supply, 0.1%; temperature, 55 °C; and time, 18 days. The bioleaching kinetics followed shrinking core model that exhibiting the shifting of mass transfer from chemically-controlled to the diffusion-controlled mechanism. This process offers two-fold advantages that restoring the valuable metals with low-emission biotechnological route for waste valorization.


Asunto(s)
Residuos Electrónicos , Clostridiales , Residuos Electrónicos/análisis , Residuos Peligrosos , Cinética , Reciclaje
19.
Front Environ Sci Eng ; 16(3): 31, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34221534

RESUMEN

Previous studies reported that specially designed ventilation systems provide good air quality and safe environment by removing airborne droplets that contain viruses expelled by infected people. These water droplets can be stable in the environment and remain suspended in air for prolonged periods. Encounters between droplets may occur and droplet interactions should be considered. However, the previous studies focused on other physical phenomena (air flow, drag force, evaporation) for droplet transport and neglected droplet interactions. In this work, we used computational fluid dynamics (CFD) to simulate the transport and fate of airborne droplets expelled by an asymptomatic person and considered droplet interactions. Droplet drag with turbulence for prediction of transport and fate of droplets indicated that the turbulence increased the transport of 1 µm droplets, whereas it decreased the transport of 50 µm droplets. In contrast to only considering drag and turbulence, consideration of droplet interactions tended to increase both the transport and fate. Although the length scale of the office is much larger than the droplet sizes, the droplet interactions, which occurred at the initial stages of release when droplet separation distances were shorter, had a significant effect in droplet fate by considerably manipulating the final locations on surfaces where droplets adhered. Therefore, it is proposed that when an exact prediction of transport and fate is required, especially for high droplet concentrations, the effects of droplet interactions should not be ignored. ELECTRONIC SUPPLEMENTARY MATERIAL: Supplementary material is available in the online version of this article at 10.1007/s11783-021-1465-8 and is accessible for authorized users.

20.
Waste Manag ; 154: 175-186, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36244206

RESUMEN

This study presents a novel recycling scheme for spent Li-ion batteries that involves the leaching of lithium in hot water followed by the dissolution of all transition metals in HCl solution and their separation using the ionic liquid Cyphos IL104. The parametric studies revealed that >84 % Li was dissolved while the cathode material was leached at 90 °C for 2 h. Approximately 98 % Li from the non-acidic solution was directly precipitated as Li2CO3 at a Li+:CO32- ratio of 1:1.5. The transition metals from the Li-depleted cathode mass were efficiently (>98 %) dissolved in 3.0 mol·L-1 HCl at 90 °C for a 3 h leaching process. Manganese from the chloride leach liquor was selectively precipitated by adding KMnO4 at a 1.25-fold higher quantity than the stoichiometric ratio, pH value 2.0, and temperature 80 °C. The remaining co-existing metals (Ni and Co) were separated from the chloride solution by contacting it with a phosphonium-based ionic liquid at an equilibrium pH value of 5.4 and an organic-to-aqueous phase ratio of 2/3. The loaded ionic liquid was quantitatively stripped in 2.0 mol·L-1 H2SO4 solution, which yielded high-purity CoSO4·xH2O crystals after evaporation of the stripped liquor. Subsequently, ∼99 % nickel was recovered as nickel carbonate [NiCO3·2Ni(OH)2] from the Co-depleted raffinate by the precipitation performed at Ni2+:CO32- ratio of 1:2.5, pH value of 10.8, and temperature of 50 °C. Finally, a process flow with mass and energy balances yielding a high recovery rate of all metals in the exhausted cathode powder of spent LiBs was proposed.

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