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1.
Cell ; 172(5): 1122-1131.e9, 2018 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-29474911

RESUMEN

The implementation of clinical-decision support algorithms for medical imaging faces challenges with reliability and interpretability. Here, we establish a diagnostic tool based on a deep-learning framework for the screening of patients with common treatable blinding retinal diseases. Our framework utilizes transfer learning, which trains a neural network with a fraction of the data of conventional approaches. Applying this approach to a dataset of optical coherence tomography images, we demonstrate performance comparable to that of human experts in classifying age-related macular degeneration and diabetic macular edema. We also provide a more transparent and interpretable diagnosis by highlighting the regions recognized by the neural network. We further demonstrate the general applicability of our AI system for diagnosis of pediatric pneumonia using chest X-ray images. This tool may ultimately aid in expediting the diagnosis and referral of these treatable conditions, thereby facilitating earlier treatment, resulting in improved clinical outcomes. VIDEO ABSTRACT.


Asunto(s)
Aprendizaje Profundo , Diagnóstico por Imagen , Neumonía/diagnóstico , Niño , Humanos , Redes Neurales de la Computación , Neumonía/diagnóstico por imagen , Curva ROC , Reproducibilidad de los Resultados , Tomografía de Coherencia Óptica
2.
J Am Chem Soc ; 146(7): 4508-4520, 2024 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-38320122

RESUMEN

Electroreduction of CO2 into liquid fuels is a compelling strategy for storing intermittent renewable energy. Here, we introduce a family of facet-defined dilute copper alloy nanocrystals as catalysts to improve the electrosynthesis of n-propanol from CO2 and H2O. We show that substituting a dilute amount of weak-CO-binding metals into the Cu(100) surface improves CO2-to-n-propanol activity and selectivity by modifying the electronic structure of catalysts to facilitate C1-C2 coupling while preserving the (100)-like 4-fold Cu ensembles which favor C1-C1 coupling. With the Au0.02Cu0.98 champion catalyst, we achieve an n-propanol Faradaic efficiency of 18.2 ± 0.3% at a low potential of -0.41 V versus the reversible hydrogen electrode and a peak production rate of 16.6 mA·cm-2. This study demonstrates that shape-controlled dilute-metal-alloy nanocrystals represent a new frontier in electrocatalyst design, and precise control of the host and minority metal distributions is crucial for elucidating structure-composition-property relationships and attaining superior catalytic performance.

3.
J Surg Res ; 300: 253-262, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38833753

RESUMEN

INTRODUCTION: Obesity is frequent among organ transplant recipients, increasing the risk of acute graft rejection and overall morbimortality. Laparoscopic sleeve gastrectomy (LSG) effectively improves graft survival and associated comorbidities. We first compared 30-d outcomes between chronic immunosuppressed (CI) and nonchronic immunosuppressed (non-CI) patients. Then, between organ transplant and non-organ transplant CI patients who underwent LSG. METHODS: Patients who underwent LSG within the metabolic and bariatric surgery accreditation and quality improvement program 2017-2019 were included. Using 1:1 and 1:4 propensity score matching analysis, the cohorts were matched for 30 characteristics. We then compared 30-d outcomes between CI and non-CI (analysis 1) and between organ transplant and non-organ transplant CI patients who underwent LSG (analysis 2). RESULTS: A total of 486,576 patients were included. The matched cohorts in analysis 1 (n = 8978) and analysis 2 (n = 1152, n = 371) had similar preoperative characteristics. Propensity score matching in analysis 1 showed that patients in the CI group had significantly higher rates of renal complications (0.4% versus 0.2%, P = 0.006), unplanned intensive care unit admission (1.1% versus 0.7%, P = 0.003), blood transfusions (1.1% versus 0.7%, P = 0.003), readmissions (4.6% versus 3.5%, P < 0.001), reoperations (1.4% versus 1.0%, P = 0.033), interventions (1.3% versus 1.0%, P = 0.026), and postoperative bleeding (0.6% versus 0.4%, P = 0.013). In analysis 2, patients with organ transplant CI had a higher rate of pulmonary complications (1.1% versus 0.3%, P = 0.043), renal complications (2.4% versus 0.2%, P < 0.001), blood transfusions (6.5% versus 1.3%, P < 0.001), and readmissions (10.0% versus 4.6%, P < 0.001). CONCLUSIONS: Patients with transplant-related CI who underwent LSG have higher 30-d postoperative complication rates compared to nontransplant-related CI patients; however, there were no differences in terms of mortality, intensive care unit admissions, staple line leaks, or bleeding. LSG is safe and feasible in this high-risk population.


Asunto(s)
Gastrectomía , Trasplante de Órganos , Complicaciones Posoperatorias , Humanos , Masculino , Femenino , Gastrectomía/efectos adversos , Persona de Mediana Edad , Adulto , Estudios Retrospectivos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Trasplante de Órganos/efectos adversos , Puntaje de Propensión , Resultado del Tratamiento , Laparoscopía/efectos adversos , Terapia de Inmunosupresión/efectos adversos , Supervivencia de Injerto , Rechazo de Injerto/epidemiología , Rechazo de Injerto/inmunología , Rechazo de Injerto/etiología
4.
Surg Endosc ; 2024 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-39037465

RESUMEN

BACKGROUND: Sleeve gastrectomy is the most common bariatric procedure and its long-term complications include inadequate weight loss, weight regain, and de novo GERD, often requiring revisional surgery. Revisions, notably re-sleeve and conversion to Roux-en-Y gastric bypass (RYGB), are frequently performed, but safety data is limited. Herein, we used the MBSAQIP database to compare 30 day outcomes of primary sleeve gastrectomy (SG) with re-sleeve (RS) and SG to RYGB conversion. METHODS: Patients who underwent primary SG, RS, and SG to RYGB conversion within the MBSAQIP data registry from January 1, 2020 to December 31, 2022 were included in this study. Using Propensity Score Matching analysis, the cohorts were matched for 23 preoperative characteristics. We then compared 30 day postoperative outcomes and bariatric-specific complications between primary SG and RS (analysis 1) and between RS and SG to RYGB conversion (analysis 2). RESULTS: A total of 302,961 were included. The matched cohorts in analysis 1 (n = 1630) and analysis 2 (n = 1633) had similar pre-operative characteristics. Propensity-matched outcomes in analysis 1 showed that patients in the RS group had significantly higher staple line leak (1.3% vs. 0.1%, p < 0.001) when compared to primary SG. Similarly, longer operative times (90.16 ± 51.90 min vs. 68.32 ± 37.54 min, p < 0.001) and higher rates of readmissions (5.5% vs. 2.1%, p < 0.001), reoperations (2.3% vs. 0.6%, p < 0.001), interventions (2.5% vs. 0.4%, p < 0.001) were found in those who underwent RS. In analysis 2, RS showed higher leak rates (1.3% vs. 0.5%, p = 0.015) when compared to conversion from SG to RYGB. CONCLUSION: The RS group has a higher risk of staple line leaks compared to primary SG and conversion from SG to RYGB. In our study, there was a 2.6-fold increase in staple line leak after re-sleeve compared to RYGB conversion and a 13-fold increase compared to primary SG.

5.
Surg Endosc ; 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38862824

RESUMEN

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) in patients with BMI ≥ 60 presents technical challenges, that might be overcome by robotic surgery, but its effectiveness has not been rigorously evaluated. We compared the 30-day outcomes of LSG and robotic sleeve gastrectomy (RSG) in patients with BMI < 60 versus ≥ 60 and between LSG and RSG in patients with BMI ≥ 60. METHODS: Patients aged 18-65 years who underwent sleeve gastrectomy were included using the 2019-2022 MBSAQIP database. We performed a Propensity Score Matching analysis, with 21 preoperative characteristics. We compared 30-day postoperative outcomes for patients with BMI < 60 versus ≥ 60 using either a laparoscopic (Analysis 1) or robotic approach (Analysis 2) and compared LSG versus RSG in patients with BMI ≥ 60 (Analysis 3). RESULTS: 297,250 patients underwent LSG and 81,008 RSG. Propensity-matched¸ outcomes in analysis 1 (13,503 matched cases), showed that patients with BMI ≥ 60 had higher rates of mortality (0.1% vs. 0.0%, p = 0.014), staple line leak (0.3% vs. 0.2%, p = 0.035), postoperative bleeding (0.2% vs 0.1%, p = 0.028), readmissions (3.5% vs. 2.4%, p < 0.001), and interventions (0.7% vs. 0.5%, p = 0.028) when compared to patients with BMI < 60. In analysis 2 (4350 matched cases), patients with BMI ≥ 60 demonstrated longer operative times, length of stay, and higher rates of unplanned ICU when compared to patients with BMI < 60. In analysis 3 (4370 matched cases), patients who underwent RSG had fewer readmissions (2.9% vs. 3.7%, p = 0.037), staple line leaks (0.1% vs. 0.3%, p = 0.029), and postoperative bleeding (0.1% vs. 0.3%, p = 0.045), compared to LSG. Conversely, a longer operative time (92.74 ± 38.65 vs. 71.69 ± 37.45 min, p < 0.001) was reported. CONCLUSION: LSG patients with BMI ≥ 60 have higher rates of complications compared to patients with a BMI < 60. Moreover, some outcomes may be improved with the robotic approach in patients with BMI ≥ 60. These results underscore the importance of considering a robotic approach in this super super obese population.

6.
Nano Lett ; 23(10): 4471-4478, 2023 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-37155184

RESUMEN

Metal ion intercalation into Group VI transition metal dichalcogenides enables control over their carrier transport properties. In this work, we demonstrate a low-temperature, solution-phase synthetic method to intercalate cationic vanadium complexes into bulk WS2. Vanadium intercalation expands the interlayer spacing from 6.2 to 14.2 Å and stabilizes the 1T' phase of WS2. Kelvin-probe force microscopy measurements indicate that vanadium binding in the van der Waals gap causes an increase in the Fermi level of 1T'-WS2 by 80 meV due to hybridization of vanadium 3d orbitals with the conduction band of the TMD. As a result, the carrier type switches from p-type to n-type, and carrier mobility increases by an order of magnitude relative to the Li-intercalated precursor. Both the conductivity and thermal activation barrier for carrier transport are readily tuned by varying the concentration of VCl3 during the cation-exchange reaction.

7.
Angew Chem Int Ed Engl ; 63(19): e202317710, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38407502

RESUMEN

Stereoselective hydrogenation of tetrasubstituted olefins is an attractive method to access compounds with two contiguous stereocenters. However, homogeneous catalysts for enantio- and diastereoselective hydrogenation exhibit low reactivity toward tetrasubstituted olefins due to steric crowding between the ligand scaffold and the substrate. Monometallic heterogeneous catalysts, on the other hand, provide accessible surface active sites for hindered olefins but exhibit unpredictable and inconsistent stereoinduction. In this work, we develop a Pt-Ni bimetallic alloy catalyst that can diastereoselectively hydrogenate unactivated, sterically-bulky tetrasubstituted olefins, utilizing the more oxophilic Ni atoms to adsorb a hydroxyl directing group and direct facially-selective hydrogen addition to the olefin via the Pt atoms. Structure-activity studies on several Pt-Ni compositions underscore the importance of exposing a uniform PtNi alloy surface to achieve high diastereoselectivity and minimize side reactions. The optimized Pt-Ni/SiO2 catalyst exhibits good functional group tolerance and broad scope for tetrasubstituted olefins in a cyclopentene scaffold, generating cyclopentanol products with three contiguous stereocenters. The synthetic utility of the method is demonstrated in a four-step synthesis of (1R,2S)-(+)-cis-methyldihydrojasmonate with high yield and enantiopurity.

8.
Nicotine Tob Res ; 25(1): 19-27, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-35894290

RESUMEN

INTRODUCTION: Poly-tobacco use (PTU), or the concomitant use of two or more nicotine and tobacco products, are a growing public health concern. Adults reporting increased psychological distress (PD) experience profound nicotine and tobacco health-related disparities. Sexual minority (SM) adults report more PTU and higher levels of PD than heterosexuals, yet little is known about patterns of nicotine and tobacco use and its relationship to PD in SM populations. AIMS AND METHODS: The purpose of this study was to investigate sexual identity differences in PD and PTU. Data were drawn from the 2016-2018 National Health Interview Survey (N = 83 017), an annual cross-sectional survey of a nationally representative sample of U.S. adults. PD was assessed using the Kessler Psychological Distress Scale (K6). We fit sex-stratified, weighted, adjusted logistic models to compare PTU and PD by sexual identity. RESULTS: PTU was more prevalent in adults with higher K6 scores. Female adults and SM adults had significantly higher K6 scores and were significantly more likely to experience serious PD when compared to their male and heterosexual counterparts. CONCLUSIONS: The current study provides a snapshot of trends in PTU in relation to PD, gender, and sexual identity. Findings suggest higher rates of both PD and PTU in SM adults. Further research examining the mechanisms underlying this disparity is critical to the development of effective intervention and prevention strategies. IMPLICATIONS: Little is known about sex and sexual identity differences in the relations between patterns of tobacco product use and PD. This study is the first to examine the effect of gender and sexual identity on both PD and PTU. SMs reported higher rates of PD and were more likely to be poly-tobacco users. As new ways of engaging nicotine/tobacco continue to proliferate, health risks will endure especially for marginalized populations. An increased understanding of the psychological and social correlates of PTU in SMs is warranted.


Asunto(s)
Distrés Psicológico , Minorías Sexuales y de Género , Adulto , Masculino , Femenino , Humanos , Estudios Transversales , Nicotina , Uso de Tabaco/psicología
9.
Surg Endosc ; 37(9): 7106-7113, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37400685

RESUMEN

BACKGROUND: Severe obesity is a relative contraindication for renal transplantation, therefore bariatric surgery is an important option as a pre-kidney transplant weight loss strategy. However, comparative data regarding postoperative outcomes of laparoscopic sleeve gastrectomy (LSG) or laparoscopic Roux-en-Y gastric bypass (LRYGB) in patients with or without ESRD on dialysis are scarce. METHODS: Patients between 18- and 80-year-old who underwent LSG and RYGB were included. To determine the outcomes of patient who underwent bariatric surgery with ESRD on dialysis, a 1:4 PSM was performed between the patients with ESRD on dialysis and those without renal disease. The PSM analyses in both groups were performed using 20 preoperative characteristics. Then 30-day postoperative outcomes were assessed. RESULTS: The operative time and postoperative-LOS were significantly longer in ESRD patients on dialysis compared to those with no renal disease either for LSG (82.37 ± 40.42 vs. 73.62 ± 38.65; P < 0.001, 2.22 ± 3.01 vs. 1.67 ± 1.90; P < 0.001) or for LRYGB (129.13 ± 63.20 vs. 118.72 ± 54.16; P = 0.002, 2.53 ± 1.74 vs. 2.00 ± 1.68; P < 0.001). In the LSG cohort (2137 vs. 8495 matched cases), patients with ESRD on dialysis showed significant increase in mortality (0.7% vs 0.3%; P = 0.019), unplanned ICU admission (3.1% vs 1.3%; P < 0.001), blood transfusions (2.3% vs 0.8%; P 0.001), readmissions (9.1% vs. 4.0%; P < 0.001), reoperations (3.4% vs. 1.2%; P < 0.001), interventions (2.3% vs. 1.0%; P = 0.006). In the LRYGB group (443 vs. 1769 matched cases), patients with ESRD on dialysis showed a significantly higher need for unplanned ICU admission (3.8% vs. 1.4%; P = 0.027), readmissions (12.4% vs. 6.6%; P = 0.011), and interventions (5.2% vs. 2.0%; P = 0.050). CONCLUSION: Bariatric surgery is a safe procedure for patients with ESRD on dialysis to help them get a kidney transplant. Even though this group experienced a higher incidence of postoperative complications compared to those without kidney disease, the absolute complication rates are low and not associated with bariatric-specific complications. Therefore, ESRD should not be perceived as contraindications to bariatric surgery.


Asunto(s)
Cirugía Bariátrica , Derivación Gástrica , Fallo Renal Crónico , Trasplante de Riñón , Laparoscopía , Obesidad Mórbida , Humanos , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Diálisis Renal , Cirugía Bariátrica/efectos adversos , Cirugía Bariátrica/métodos , Derivación Gástrica/métodos , Obesidad Mórbida/complicaciones , Obesidad Mórbida/cirugía , Obesidad Mórbida/epidemiología , Laparoscopía/efectos adversos , Gastrectomía/métodos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Fallo Renal Crónico/cirugía , Resultado del Tratamiento , Estudios Retrospectivos
10.
Surg Endosc ; 37(10): 7947-7954, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37433912

RESUMEN

BACKGROUND: Secondary bariatric surgery rates have increased, accounting for approximately 19% of the total bariatric cases in the last years, most commonly conversion of sleeve gastrectomy to gastric bypass. Using the MBSAQIP, we evaluate the outcomes of this procedure compared to the primary RYGB surgery. METHODS: The new variable, conversion of sleeve gastrectomy to RYGB in the 2020 and 2021 MBSAQIP database was analyzed. Patients who underwent primary laparoscopic RYGB and those who underwent laparoscopic sleeve gastrectomy to RYGB conversion were identified. Using Propensity Score Matching analysis, the cohorts were matched for 21 preoperative characteristics. We then compared 30-day outcomes and bariatric-specific complications between primary RYGB and conversion from sleeve gastrectomy to RYGB. RESULTS: There were 43,253 primary RYGB procedures performed and 6,833 conversions from sleeve gastrectomy to RYGB. The matched cohorts (n = 5912) for the two groups have similar pre-operative characteristics. Propensity-matched outcomes showed that conversion from sleeve gastrectomy to RYGB was associated with more readmissions (6.9% vs 5.0%, p < 0.001), interventions (2.6% vs 1.7%, p < 0.001), conversion to open (0.7% vs 0.2%, p < 0.001), length of stay (1.79 ± 1.77 days vs 1.62 ± 1.66 days, p < 0.001), and operative time (119.16 ± 56.82 min vs 138.27 ± 66.00, p < 0.001). There were no significant differences in mortality (0.1% vs 0.1%, p = 0.405), and bariatric-specific complications such as anastomotic leak (0.5% vs 0.4%, p = 0.585), intestinal obstruction (0.1% vs 0.2%, p = 0.808), internal hernia (0.2% vs 0.1%, p = 0.285) or anastomotic ulcer (0.3% vs 0.3%, p = 0.731) rates. CONCLUSION: Conversion from sleeve gastrectomy to RYGB is a safe and feasible operation with reasonable outcomes compared with primary RYGB.


Asunto(s)
Derivación Gástrica , Laparoscopía , Obesidad Mórbida , Humanos , Derivación Gástrica/efectos adversos , Derivación Gástrica/métodos , Obesidad Mórbida/cirugía , Puntaje de Propensión , Estudios Retrospectivos , Laparoscopía/métodos , Gastrectomía/efectos adversos , Gastrectomía/métodos , Resultado del Tratamiento
11.
Surg Endosc ; 37(10): 7970-7979, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37439819

RESUMEN

BACKGROUND: This study aims to compare outcomes and utilization of robotics in bariatric procedures across two-time intervals, chosen because they correspond to drastic changes in technology utilization-namely, a new platform and a new stapling device. Outcomes of robotic Roux-en-Y gastric bypass (rRYGB) and robotic sleeve gastrectomy (rSG) across this changing landscape have not been well studied, despite increasing popularity. METHODS: The MBSAQIP database was analyzed over early (2015-2016) and late (2019-2020) time intervals. Patients who underwent rSG and rRYGB were identified, and the cohorts were matched for 26 preoperative characteristics using Propensity Score Matching Analysis. We then compared 30-day outcomes and bariatric-specific complications between the early and late time frames for rSG and rRYGB. RESULTS: 49,442 rSG were identified: 13,526 cases in the early time frame and 35,916 in the late time frame. The matched cohorts were 13,526 for the two groups. 30-day outcomes showed that in the late time frame, rSG was associated with lower rates of pulmonary complications (0.1% vs 0.3%, p < 0.001), readmissions (2.5% vs 3.6%, p < 0.001), interventions (0.6% vs 1.4%, p < 0.001), reoperations (0.7% vs 1.0%, p = 0.024), length of stay (1.36 ± 1.01 days vs 1.76 ± 1.79 days, p < 0.001), operative time (92.47 ± 41.70 min vs102.76 ± 45.67 min p < 0.001), staple line leaks (0.2% vs 0.4%, p = 0.001) and strictures (0.0% vs 0.2%, p < 0.001). Similarly, 21,933 rRYGB were found: 6,514 cases were identified in the early time frame and 15,419 in the late time frame. The matched cohorts were 6,513 for the two groups. 30-day outcomes revealed that the late time fame rRYGB was associated with lower rates of pulmonary complications (0.1% vs 0.3%, p = 0.012), readmissions (6.3% vs 7.2%, p = 0.050), interventions (2.0% vs 3.1%, p < 0.001), length of stay (1.69 ± 1.46 days vs 2.13 ± 2.12 days p < 0.001), postoperative bleeding (0.4% vs 0.7%, p = 0.001), stricture (0.4% vs 0.8%, p < 0.001) and anastomotic ulcer (0.2% vs 0.4%, p = 0.013). CONCLUSION: Compared to early robotic bariatric surgery outcomes, a significant reduction in pulmonary complications, readmissions, reoperations, interventions and length of stay were seen in 2019-20 after rSG and rRYGB. Potential contributing factors include increased surgical experience and advances in the robotic platform. A significant recent reduction in staple line leaks with faster operative times associated with rSG suggests that stapling technology has had a positive impact on patient outcomes.


Asunto(s)
Cirugía Bariátrica , Derivación Gástrica , Laparoscopía , Obesidad Mórbida , Procedimientos Quirúrgicos Robotizados , Robótica , Humanos , Obesidad Mórbida/cirugía , Obesidad Mórbida/complicaciones , Estudios Retrospectivos , Cirugía Bariátrica/efectos adversos , Cirugía Bariátrica/métodos , Derivación Gástrica/métodos , Procedimientos Quirúrgicos Robotizados/efectos adversos , Procedimientos Quirúrgicos Robotizados/métodos , Laparoscopía/métodos , Gastrectomía/efectos adversos , Gastrectomía/métodos , Resultado del Tratamiento , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía
12.
Nano Lett ; 22(19): 7811-7818, 2022 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-36130299

RESUMEN

Achieving superradiance in solids is challenging due to fast dephasing processes from inherent disorder and thermal fluctuations. Perovskite quantum dots (QDs) are an exciting class of exciton emitters with large oscillator strength and high quantum efficiency, making them promising for solid-state superradiance. However, a thorough understanding of the competition between coherence and dephasing from phonon scattering and energetic disorder is currently unavailable. Here, we present an investigation of exciton coherence in perovskite QD solids using temperature-dependent photoluminescence line width and lifetime measurements. Our results demonstrate that excitons are coherently delocalized over 3 QDs at 11 K in superlattices leading to superradiant emission. Scattering from optical phonons leads to the loss of coherence and exciton localization to a single QD at temperatures above 100 K. At low temperatures, static disorder and defects limit exciton coherence. These results highlight the promise and challenge in achieving coherence in perovskite QD solids.

13.
Angew Chem Int Ed Engl ; 62(49): e202311575, 2023 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-37844276

RESUMEN

Black phosphorus (bP) is a two-dimensional van der Waals material unique in its potential to serve as a support for single-site catalysts due to its similarity to molecular phosphines, ligands quintessential in homogeneous catalysis. However, there is a scarcity of synthetic methods to install single metal centers on the bP lattice. Here, we demonstrate the functionalization of bP nanosheets with molecular Re and Mo complexes. A suite of characterization techniques, including infrared, X-ray photoelectron and X-ray absorption spectroscopy as well as scanning transmission electron microscopy corroborate that the functionalized nanosheets contain a high density of discrete metal centers directly bound to the bP surface. Moreover, the supported metal centers are chemically accessible and can undergo ligand exchange transformations without detaching from the surface. The steric and electronic properties of bP as a ligand are estimated with respect to molecular phosphines. Sterically, bP resembles tri(tolyl)phosphine when monodentate to a metal center, and bis(diphenylphosphino)propane when bidentate, whereas electronically bP is a σ-donor as strong as a trialkyl phosphine. This work is foundational in elucidating the nature of black phosphorus as a ligand and underscores the viability of using bP as a basis for single-site catalysts.

14.
Surg Endosc ; 36(9): 6886-6895, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35020060

RESUMEN

BACKGROUND: Up to 37% of class three obesity patients have a Hiatal Hernia (HH). Most of the existent HHs get repaired at the time of bariatric surgery. Although the robotic platform might offer potential technical advantages over traditional laparoscopy, the clinical outcomes of the concurrent bariatric surgery and HH repair comparing robotic vs laparoscopic approaches have not been reported. METHODS: Using the 2015-2018 Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database, patients between 18 and 65 year old who underwent Sleeve gastrectomy (SG) or Roux en-Y Gastric Bypass (RYGB) with concurrent HH repair were identified. Demographic, operative, and 30-day postoperative outcomes data were compared between laparoscopic and robotic groups. To adjust for potential confounders, 1:1 propensity score matching was performed using 22 preoperative characteristics. RESULTS: 75,034 patients underwent SG (n = 61,458) or RYGB (n = 13,576) with concurrent HH repair. The operative time was significantly longer in the Robotic-assisted compared to the laparoscopic approach both for SG (102.31 ± 44 vs. 75.27 ± 37; P < 0.001) and for RYGB (163.48 ± 65 vs. 132.87 ± 57; P < 0.001). In the SG cohort (4639 matched cases), the robotic approach showed similar results in 30 day outcomes as in the laparoscopic approach, with no statistical difference. Conversely, for the RYGB cohort (1502 matched cases), the robotic approach showed significantly fewer requirements for blood transfusions (0.3% vs. 1.7%; P = 0.001), fewer anastomotic leaks (0.2% vs. 0.8%; P = 0.035), and less postoperative bleeding (0.4% vs. 1.1%; P = 0.049). CONCLUSION: Robotic concurrent bariatric surgery and HH repair leads to similar overall clinical outcomes as the laparoscopic approach despite longer operative times. Furthermore, the robotic approach is associated with reduced blood transfusion and anastomotic leak incidence in the RYGB group.


Asunto(s)
Cirugía Bariátrica , Derivación Gástrica , Laparoscopía , Obesidad Mórbida , Robótica , Acreditación , Adolescente , Adulto , Anciano , Fuga Anastomótica/cirugía , Cirugía Bariátrica/métodos , Gastrectomía/efectos adversos , Gastrectomía/métodos , Derivación Gástrica/efectos adversos , Derivación Gástrica/métodos , Herniorrafia/métodos , Humanos , Laparoscopía/métodos , Persona de Mediana Edad , Obesidad Mórbida/complicaciones , Obesidad Mórbida/cirugía , Puntaje de Propensión , Mejoramiento de la Calidad , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
15.
Surg Endosc ; 36(11): 8481-8489, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35226162

RESUMEN

BACKGROUND: There is an increased incidence of post-operative bleeding in patients on chronic anticoagulation (CAC). This incited some surgeons to oversew the sleeve staple line as a potentially preventive measure for post-operative bleeding. However, there is no clear evidence to assess the effectiveness of staple line oversewing during laparoscopic sleeve gastrectomy (LSG) in patients with CAC. METHODS: Using the 2015-2018 metabolic and bariatric surgery accreditation and quality improvement program database, patients between ages 18 and 65 who underwent LSG were included. To investigate the role of CAC, we performed 1:1 propensity score matching (PSM) between the CAC and non-CAC patients. Then, to explore the impact of oversewing, we focused on the CAC patients and divided them into 2 subgroups: oversewing versus non-oversewing. PSM was also performed to compare both subgroups. To avoid confounders, both PSM analyses were performed using 22 preoperative characteristics. 30-day postoperative outcomes including bleeding and blood transfusion requirement were assessed. RESULTS: 402,826 patients underwent LSG. 9148 patients (2.3%) were on CAC. In the CAC cohort (8843 matched cases), the anticoagulated patients showed significant increase in postoperative bleeding (1.2% vs. 0.5%; P < 0.001), blood transfusion requirements (1.7% vs. 0.7%; P < 0.001), unplanned ICU admissions (2.0% vs. 1.3%; P = 0.001), interventions (2.0% vs. 1.5%; P = 0.015), and readmissions (6.2% vs. 4.7%; P < 0.001). 1939 (21.2%) patients on CAC underwent oversewing during the LSG. The operative time was significantly longer in these patients (87.11 ± 40 vs. 76.19 ± 37; P < 0.001). Patients who underwent oversewing showed similar results in 30-day outcomes as those who did not, with no statistical difference, including postoperative bleeding (1.0% vs. 0.9%; P = 0.8) and blood transfusion requirements (1.4% vs. 1.8%; P = 0.9). CONCLUSION: Incidences of post-operative bleeding and blood transfusion requirements are higher in patients on CAC during the LSG. Oversewing the sleeve staple line leads to longer operative times without additional benefit in 30-day outcomes.


Asunto(s)
Laparoscopía , Obesidad Mórbida , Humanos , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Anciano , Obesidad Mórbida/cirugía , Obesidad Mórbida/complicaciones , Puntaje de Propensión , Laparoscopía/efectos adversos , Laparoscopía/métodos , Gastrectomía/efectos adversos , Gastrectomía/métodos , Grapado Quirúrgico/métodos , Hemorragia Posoperatoria/epidemiología , Hemorragia Posoperatoria/etiología , Hemorragia Posoperatoria/cirugía , Anticoagulantes/efectos adversos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Resultado del Tratamiento , Estudios Retrospectivos
16.
Inorg Chem ; 60(10): 6950-6956, 2021 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-33835781

RESUMEN

Electronic doping of transition-metal oxides (TMOs) is typically accomplished through the synthesis of nonstoichiometric oxide compositions and the subsequent ionization of intrinsic lattice defects. As a result, ambipolar doping of wide-band-gap TMOs is difficult to achieve because the formation energies and stabilities of vacancy and interstitial defects vary widely as a function of the oxide composition and crystal structure. The facile formation of lattice defects for one carrier type is frequently paired with the high-energy and unstable generation of defects required for the opposite carrier polarity. Previous work from our group showed that the brucite (ß-phase) layered metal hydroxides of Co and Ni, intrinsically p-type materials in their anhydrous three-dimensional forms, could be n-doped using a strong chemical reductant. In this work, we extend the electron-doping study to the α polymorph of Co(OH)2 and elucidate the defects responsible for n-type doping in these two-dimensional materials. Through structural and electronic comparisons between the α, ß, and rock-salt structures within the cobalt (hydr)oxide family of materials, we show that both layered structures exhibit facile formation of anion vacancies, the necessary defect for n-type doping, that are not accessible in the cubic CoO structure. However, the brucite polymorph is much more stable to reductive decomposition in the presence of doped electrons because of its tighter layer-to-layer stacking and octahedral coordination geometry, which results in a maximum conductivity of 10-4 S/cm, 2 orders of magnitude higher than the maximum value attainable on the α-Co(OH)2 structure.

17.
Nano Lett ; 20(10): 7580-7587, 2020 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-32877192

RESUMEN

Ambipolar doping of metal oxides is critical toward broadening the functionality of semiconducting oxides in electronic devices. Most metal oxides, however, show a strong preference for a single doping polarity due to the intrinsic stability of particular defects in an oxide lattice. In this work, we demonstrate that layered metal hydroxide nanomaterials of Co and Ni, which are intrinsically p-doped in their anhydrous rock salt form, can be n-doped using n-BuLi as a strong electron donor. A combination of X-ray characterization techniques reveal that hydroxide vacancy formation, Li+ adsorption, and varying degrees of electron delocalization are responsible for the stability of injected electrons. The doped electrons induce conductivity increases of 4-6 orders of magnitude relative to the undoped M(OH)2. We anticipate that chemical electron doping of layered metal hydroxides may be a general strategy to increase carrier concentration and stability for n-doping of intrinsically p-type metal oxides.

18.
Biomacromolecules ; 21(9): 3945-3956, 2020 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-32786527

RESUMEN

Oral bacterial infection represents the leading cause of the gradual destruction of tooth and periodontal structures anchoring the teeth. Lately, injectable hydrogels have gained increased attention as a promising minimally invasive platform for localized delivery of personalized therapeutics. Here, an injectable and photocrosslinkable gelatin methacryloyl (GelMA) hydrogel is successfully engineered with ciprofloxacin (CIP)-eluting short nanofibers for oral infection ablation. For this purpose, CIP or its ß-cyclodextrin (ß-CD)-inclusion complex (CIP/ß-CD-IC) has been incorporated into polymeric electrospun fibers, which were subsequently cut into short nanofibers, and then embedded in GelMA to obtain an injectable hybrid antimicrobial hydrogel. Thanks to the solubility enhancement of CIP by ß-CD-IC and the tunable degradation profile of GelMA, the hydrogels promote localized, sustained, and yet effective cell-friendly antibiotic doses, as measured by a series of bacterial assays that demonstrated efficacy in attenuating the growth of Gram-positive Enterococcus faecalis. Altogether, we foresee significant potential in translating this innovative hybrid hydrogel as an injectable platform technology that may have broad applications in oral infection ablation, such as periodontal disease and pulpal pathology.


Asunto(s)
Antiinfecciosos , Nanofibras , Antibacterianos/farmacología , Gelatina , Hidrogeles
19.
Nature ; 508(7497): 504-7, 2014 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-24717429

RESUMEN

The electrochemical conversion of CO2 and H2O into liquid fuel is ideal for high-density renewable energy storage and could provide an incentive for CO2 capture. However, efficient electrocatalysts for reducing CO2 and its derivatives into a desirable fuel are not available at present. Although many catalysts can reduce CO2 to carbon monoxide (CO), liquid fuel synthesis requires that CO is reduced further, using H2O as a H(+) source. Copper (Cu) is the only known material with an appreciable CO electroreduction activity, but in bulk form its efficiency and selectivity for liquid fuel are far too low for practical use. In particular, H2O reduction to H2 outcompetes CO reduction on Cu electrodes unless extreme overpotentials are applied, at which point gaseous hydrocarbons are the major CO reduction products. Here we show that nanocrystalline Cu prepared from Cu2O ('oxide-derived Cu') produces multi-carbon oxygenates (ethanol, acetate and n-propanol) with up to 57% Faraday efficiency at modest potentials (-0.25 volts to -0.5 volts versus the reversible hydrogen electrode) in CO-saturated alkaline H2O. By comparison, when prepared by traditional vapour condensation, Cu nanoparticles with an average crystallite size similar to that of oxide-derived copper produce nearly exclusive H2 (96% Faraday efficiency) under identical conditions. Our results demonstrate the ability to change the intrinsic catalytic properties of Cu for this notoriously difficult reaction by growing interconnected nanocrystallites from the constrained environment of an oxide lattice. The selectivity for oxygenates, with ethanol as the major product, demonstrates the feasibility of a two-step conversion of CO2 to liquid fuel that could be powered by renewable electricity.

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