Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Proc Natl Acad Sci U S A ; 121(24): e2318124121, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38830100

RESUMEN

There is much excitement about the opportunity to harness the power of large language models (LLMs) when building problem-solving assistants. However, the standard methodology of evaluating LLMs relies on static pairs of inputs and outputs; this is insufficient for making an informed decision about which LLMs are best to use in an interactive setting, and how that varies by setting. Static assessment therefore limits how we understand language model capabilities. We introduce CheckMate, an adaptable prototype platform for humans to interact with and evaluate LLMs. We conduct a study with CheckMate to evaluate three language models (InstructGPT, ChatGPT, and GPT-4) as assistants in proving undergraduate-level mathematics, with a mixed cohort of participants from undergraduate students to professors of mathematics. We release the resulting interaction and rating dataset, MathConverse. By analyzing MathConverse, we derive a taxonomy of human query behaviors and uncover that despite a generally positive correlation, there are notable instances of divergence between correctness and perceived helpfulness in LLM generations, among other findings. Further, we garner a more granular understanding of GPT-4 mathematical problem-solving through a series of case studies, contributed by experienced mathematicians. We conclude with actionable takeaways for ML practitioners and mathematicians: models that communicate uncertainty, respond well to user corrections, and can provide a concise rationale for their recommendations, may constitute better assistants. Humans should inspect LLM output carefully given their current shortcomings and potential for surprising fallibility.


Asunto(s)
Lenguaje , Matemática , Solución de Problemas , Humanos , Solución de Problemas/fisiología , Estudiantes/psicología
2.
J Am Chem Soc ; 145(40): 22158-22167, 2023 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-37779473

RESUMEN

Li-SOCl2 batteries possess ultrahigh energy densities and superior safety features at a wide range of operating temperatures. However, the Li-SOCl2 battery system suffers from poor reversibility due to the sluggish kinetics of SOCl2 reduction during discharging and the oxidation of the insulating discharge products during charging. To achieve a high-power rechargeable Li-SOCl2 battery, herein we introduce the molecular catalyst I2 into the electrolyte to tailor the charging and discharging reaction pathways. The as-assembled rechargeable cell exhibits superior power density, sustaining an ultrahigh current density of 100 mA cm-2 during discharging and delivering a reversible capacity of 1 mAh cm-2 for 200 cycles at a current density of 2 mA cm-2 and 6 mAh cm-2 for 50 cycles at a current density of 5 mA cm-2. Our results reveal the molecular catalyst-mediated reaction mechanisms that fundamentally alter the rate-determining steps of discharging and charging in Li-SOCl2 batteries and highlight the viability of transforming a primary high-energy battery into a high-power rechargeable system, which has great potential to meet the ever-increasing demand of energy-storage systems.

3.
Br J Anaesth ; 130(2): 191-201, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36088134

RESUMEN

BACKGROUND: Early exposure to general anaesthetics for multiple surgeries or procedures might negatively affect brain development. Recent studies indicate the importance of microbiota in the development of stress-related behaviours. We determined whether repeated anaesthesia and surgery in early life cause gut microbiota dysbiosis and anxiety-like behaviours in rats. METHODS: Sprague Dawley rats received skin incisions under sevoflurane 2.3 vol% three times during the first week of life. After 4 weeks, gut microbiota, anxiety-related behaviours, hippocampal serotonergic activity, and plasma stress hormones were tested. Subsequently, we explored the effect of faecal microbiota transplantation from multiple anaesthesia/surgery exposed rats after administration of a cocktail of antibiotics on anxiety-related behaviours. RESULTS: Anxiety-like behaviours were observed in rats with repeated anaesthesia/surgery exposures: In the OF test, multiple anaesthesia/surgery exposures induced a decrease in the time spent in the centre compared to the Control group (P<0.05, t=3.05, df=16, Cohen's d=1.44, effect size=0.58). In the EPM test, rats in Multiple AS group travelled less (P<0.05, t=5.09, df=16, Cohen's d=2.40, effective size=0.77) and spent less time (P<0.05, t=3.58, df=16, Cohen's d=1.69, effect size=0.65) in the open arms when compared to the Control group. Repeated exposure caused severe gut microbiota dysbiosis, with exaggerated stress response (P<0.01, t=4.048, df=16, Cohen's d=-1.91, effect size=-0.69), a significant increase in the hippocampal concentration of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) (P<0.05; for 5-HT: t=3.33, df=18, Cohen's d=-1.49, effect size=-0.60; for 5-HIAA: t=3.12, df=18, Cohen's d=-1.40, effect size=-0.57), and changes in gene expression of serotonergic receptors later in life (for Htr1a: P<0.001, t=4.49, df=16, Cohen's d=2.24, effect size=0.75; for Htr2c: P<0.01, t=3.72, df=16, Cohen's d=1.86, effect size=0.68; for Htr6: P<0.001, t=7.76, df=16, Cohen's d=3.88, effect size=0.89). Faecal microbiota transplantation led to similar anxiety-like behaviours and changes in the levels of 5-hydroxytryptamine and 5-hydroxyindoleacetic acid. CONCLUSIONS: Gut microbiota dysbiosis caused by early repeated exposure to anaesthesia and surgery affects long-term anxiety emotion behaviours in rats.


Asunto(s)
Anestesia , Microbioma Gastrointestinal , Ratas , Animales , Serotonina/metabolismo , Ácido Hidroxiindolacético , Ratas Sprague-Dawley , Disbiosis/inducido químicamente , Ansiedad/etiología
4.
Macromol Rapid Commun ; 43(14): e2100897, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35182088

RESUMEN

Conjugated polymers possess better electron conductivity due to large π-electron conjugated configuration endowing them significant scientific and technological interest. However, the obvious deficiency of active-site underutilization impairs their electrochemical performance. Therefore, designing and engineering π-conjugated polymers with rich redox functional groups and mesoporous architectures could offer new opportunities for them in these emerging applications and further expand their application scopes. Herein, a series of 1,3,5-tris(4-aminophenyl) benzene (TAPB)-based π-conjugated mesoporous polymers (π-CMPs) are constructed by one-pot emulsion-induced interface assembly strategy. Furthermore, co-induced in situ polymerization on 2D interfaces by emulsion and micelles is explored, which delivers sandwiched 2D mesoporous π-CMPs-coated graphene oxides (GO@mPTAPB). Benefiting from specific redox-active functional groups, excellent electron conductivity and a 2D mesoporous conjugated framework, GO@mPTAPB exhibits high capability of accommodating Li+ anions (up to 382 mAh g-1 at 0.2 A g-1 ) and outstanding electrochemical stability (87.6% capacity retention after 1000 cycles). The ex situ Raman and impedance spectra are further applied to reveal the high reversibility of GO@mPTAPB. This work will greatly promote the development of advanced π-CMPs-based organic anodes toward energy storage devices.

5.
Surg Endosc ; 35(1): 174-181, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-31993823

RESUMEN

BACKGROUND: The traditional open or laparoscopic segmentectomy of liver segment 7 (S7) requires exposing and controlling the root of the right hepatic vein(RHV)after full mobilization and lifting up of the right liver before liver transection. This approach violates the "no-touch" principle for malignant tumors, and makes laparoscopic resection technically challenging. So reports on isolated totally laparoscopic anatomic S7 segmentectomy have rarely been reported. This study describes our experience in laparoscopic anatomic S7 segmentectomy using in situ split along the right intersectoral and intersegmental planes of the liver. To our knowledge, this is the first description of this novel approach. METHODS: From September 2017 to May 2019, patients who underwent laparoscopic anatomic S7 segmentectomy for hepatocellular carcinoma at the HPB Surgery Department, Sun Yat-Sen Memorial Hospital entered into this retrospective study. This in situ split approach was designed using main vessels as the plane markers of right intersectoral and intersegmental planes, along which liver transection was carried out. There was no need to mobilize the right liver and control the root of RHV. RESULTS: There were 9 women and 15 men. The average diameter of the tumors on preoperative CT/MR was 3.4 cm (range 2-6 cm). All the procedures were successfully carried out laparoscopically. There was no perioperative death. The average operative time was 216.5 min (range 180-310 min). The average blood loss was 320 ml (range 120-620 ml). Pathological study showed all the operations to be R0 resections. CONCLUSION: Laparoscopic anatomic S7 segmentectomy using the in situ split approach resulted in R0 liver resection in all our patients with primary liver cancer. The operation was technically feasible and it provided a better view and increased maneuverability in the cramped operative space compared with the traditional open/laparoscopic approach. The approach also better complies with the "no-touch" principle for malignant tumors. Its long-term oncological outcomes require further studies.


Asunto(s)
Carcinoma Hepatocelular/cirugía , Hepatectomía/métodos , Laparoscopía/métodos , Neoplasias Hepáticas/cirugía , Adulto , Anciano , Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/patología , Femenino , Venas Hepáticas/cirugía , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/patología , Masculino , Persona de Mediana Edad , Tempo Operativo , Estudios Retrospectivos
6.
Liver Int ; 40(7): 1655-1669, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32329946

RESUMEN

BACKGROUND: EDP-305 is a novel and potent farnesoid X receptor (FXR) agonist, with no/minimal cross-reactivity to TGR5 or other nuclear receptors. Herein we report therapeutic efficacy of EDP-305, in direct comparison with the first-in-class FXR agonist obeticholic acid (OCA), in mouse models of liver disease. METHODS: EDP-305 (10 and 30 mg/kg/day) or OCA (30mg/kg/day) was tested in mouse models of pre-established biliary fibrosis (BALBc.Mdr2-/-, n = 9-12/group) and steatohepatitis induced by methionine/choline-deficient diet (MCD, n = 7-12/group). Effects on biliary epithelium were evaluated in vivo and in primary EpCAM + hepatic progenitor cell (HPC) cultures. RESULTS: In a BALBc.Mdr2-/- model, EDP-305 reduced serum transaminases by up to 53% and decreased portal pressure, compared to untreated controls. Periportal bridging fibrosis was suppressed by EDP-305 at both doses, with up to a 39% decrease in collagen deposition in high-dose EDP-305. In MCD-fed mice, EDP-305 treatment reduced serum ALT by 62% compared to controls, and profoundly inhibited perisinusoidal 'chicken wire' fibrosis, with over 80% reduction in collagen deposition. In both models, treatment with 30mg/kg OCA reduced serum transaminases up to 30%, but did not improve fibrosis. The limited impact on fibrosis was mediated by cholestasis-independent worsening of ductular reaction by OCA in both disease models; OCA but not EDP-305 at therapeutic doses promoted ductular proliferation in healthy mice and favoured differentiation of primary HPC towards cholangiocyte lineage in vitro. CONCLUSIONS: EDP-305 potently improved pre-established liver injury and hepatic fibrosis in murine biliary and metabolic models of liver disease, supporting the clinical evaluation of EDP-305 in fibrotic liver diseases including cholangiopathies and non-alcoholic steatohepatitis.


Asunto(s)
Ácido Quenodesoxicólico , Hígado , Animales , Ácido Quenodesoxicólico/farmacología , Fibrosis , Hígado/patología , Cirrosis Hepática/tratamiento farmacológico , Cirrosis Hepática/patología , Ratones , Ratones Endogámicos C57BL , Esteroides
7.
J Autom Reason ; 64(2): 331-360, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32063661

RESUMEN

In complex analysis, the winding number measures the number of times a path (counter-clockwise) winds around a point, while the Cauchy index can approximate how the path winds. We formalise this approximation in the Isabelle theorem prover, and provide a tactic to evaluate winding numbers through Cauchy indices. By further combining this approximation with the argument principle, we are able to make use of remainder sequences to effectively count the number of complex roots of a polynomial within some domains, such as a rectangular box and a half-plane.

8.
Surg Endosc ; 33(1): 206-215, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-29987565

RESUMEN

BACKGROUND: Although laparoscopic liver resection (LLR) has advanced into a safe and effective alternative to conventional open liver resection (OLR), it has not been widely accepted by surgeons. This article aimed to investigate the perioperative and long-term benefits of LLR versus OLR for hepatocellular carcinoma (HCC) in selected patients with well-preserved liver function and cirrhotic background. METHODS: A retrospective study was conducted on 1085 patients with HCC who underwent liver resection at Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University from July 2010 to July 2015, and 346 patients with well-preserved liver function and cirrhotic background were selected. A 1:1 propensity score matching (PSM), which is the best option to overcome selection bias, was conducted to compare the surgical outcomes and long-term prognosis between LLR and OLR. After PSM, a logistic regression analysis was used to identify the predictive risk factors of posthepatectomy liver failure (PHLF). RESULTS: By using PSM, the two groups were well balanced with 86 patients in each group. In the LLR group, only the median operation time was significantly longer than the OLR group, but the hospital stay, overall morbidity, and the incidence of PHLF were significantly decreased compared to OLR. There were no significant differences in the overall survival and disease-free survival rates between the two groups. On multivariate analysis, OLR was identified to be the only independent risk factor for PHLF. CONCLUSIONS: In selected HCC patients with well-preserved liver function and cirrhotic background, LLR could be a better option compared to OLR.


Asunto(s)
Carcinoma Hepatocelular/cirugía , Hepatectomía/métodos , Laparoscopía/métodos , Cirrosis Hepática/cirugía , Neoplasias Hepáticas/cirugía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma Hepatocelular/complicaciones , Carcinoma Hepatocelular/diagnóstico , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Cirrosis Hepática/complicaciones , Cirrosis Hepática/diagnóstico , Neoplasias Hepáticas/complicaciones , Neoplasias Hepáticas/diagnóstico , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Periodo Perioperatorio , Pronóstico , Puntaje de Propensión , Estudios Retrospectivos , Factores de Tiempo , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Adulto Joven
9.
HPB (Oxford) ; 21(7): 784-792, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30878490

RESUMEN

BACKGROUND: The objective of this meta-analysis was to evaluate the effectiveness and safety of lymph node dissection (LND) in patients with intrahepatic cholangiocarcinoma (ICC). METHODS: A literature search with a date range of January 2000 to January 2018 was performed to identify studies comparing lymph node dissection (LND+) with non-lymph node dissection (LND-) for patients with ICC. The LND + group was further divided into positive (LND + N+) and negative (LND + N-) lymph node status groups based on pathological analysis. RESULTS: 13 studies including 1377 patients were eligible. There were no significant differences in overall survival (OS) (HR 1.13, 95% CI 0.94-1.36; P = 0.20), disease-free survival (DFS) (HR 1.23, 95% CI 0.94-1.60; P = 0.13), or recurrence (OR 1.39, 95% CI 0.90-2.15; P = 0.14) between LND + group and LND-group. Postoperative morbidity was significantly higher in the LND + group (OR 2.67, 95% CI 1.74-4.10; P < 0.001). A subset analysis showed that OS was similar between LND + N- and LND-groups (HR 1.13, 95% CI 0.82-1.56; P = 0.450). However when comparing, OS of the LND-group to the LND+N+ group there was a significant increase in OS for the LND-group (HR 3.26, 95% CI 1.85-5.76; P < 0.001). CONCLUSIONS: LND does not seem to positively affect overall survival and is associated with increased post-operative morbidity.


Asunto(s)
Neoplasias de los Conductos Biliares/cirugía , Colangiocarcinoma/cirugía , Hepatectomía , Escisión del Ganglio Linfático , Ganglios Linfáticos/cirugía , Neoplasias de los Conductos Biliares/mortalidad , Neoplasias de los Conductos Biliares/secundario , Colangiocarcinoma/mortalidad , Colangiocarcinoma/secundario , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Hepatectomía/efectos adversos , Hepatectomía/mortalidad , Humanos , Escisión del Ganglio Linfático/efectos adversos , Escisión del Ganglio Linfático/mortalidad , Ganglios Linfáticos/patología , Metástasis Linfática , Factores de Riesgo , Factores de Tiempo
10.
J Cell Mol Med ; 22(7): 3679-3690, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29722127

RESUMEN

The cell surface antigen CD90 has recently been established as a promising marker for liver cancer stem cells. This study aimed to investigate potential implications of SHH/Gli signalling in CD90+ liver cancer stem cells. Correlation of the expression of SHH signalling components and CD90 in liver cancer cells and clinical tissues, as well as in enriched CD90+ liver cancer stem cells and the TCGA database, were analysed by quantitative RT-PCR, Western blotting and flow cytometry. Functional analysis was conducted by siRNA-mediated CD90, Gli1 and Gli3 gene knockdown, SHH treatment and application of the JAK2 inhibitor AZD1480 and IL6 neutralizing antibody in CD90+ liver cancer stem cells, followed by cell proliferation, migration, sphere formation and tumorigenicity assays. CD90 expression exhibited a high positive correlation with Gli1 and Gli3 in multiple liver cancer cell lines and human cancerous liver tissues, both of which showed a significant increase in liver cancer. Analysis of TCGA data revealed an association of CD90, Gli1 and Gli3 with a short overall survival and positive correlation between CD90 expression and Gli3 expression level. The stem cell potentials of CD90+ 97L liver cancer cells were greatly impaired by Gli1/3 knockdown with siRNA but enhanced by SHH treatment. Application of the JAK2 inhibitor AZD1480 and IL6 neutralizing antibody showed the CD90 and SHH/Gli-regulated liver cancer stem cell functions were mediated by the IL6/JAK2/STAT3 pathway. The stem cell properties of CD90+ liver cancer cells are regulated by the downstream SHH/Gli and IL6/JAK2/STAT3 signalling pathways.


Asunto(s)
Neoplasias Hepáticas/patología , Células Madre Neoplásicas/patología , Proteínas del Tejido Nervioso/metabolismo , Antígenos Thy-1/metabolismo , Proteína con Dedos de Zinc GLI1/metabolismo , Proteína Gli3 con Dedos de Zinc/metabolismo , Línea Celular Tumoral , Femenino , Regulación Neoplásica de la Expresión Génica , Proteínas Hedgehog/metabolismo , Humanos , Interleucina-6/metabolismo , Janus Quinasa 2/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/mortalidad , Masculino , Células Madre Neoplásicas/metabolismo , Proteínas del Tejido Nervioso/genética , Factor de Transcripción STAT3/metabolismo , Antígenos Thy-1/genética , Proteína con Dedos de Zinc GLI1/genética , Proteína Gli3 con Dedos de Zinc/genética
11.
Plant Cell ; 26(3): 862-75, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24632533

RESUMEN

Auxin is a key regulator of plant growth and development. Within the root tip, auxin distribution plays a crucial role specifying developmental zones and coordinating tropic responses. Determining how the organ-scale auxin pattern is regulated at the cellular scale is essential to understanding how these processes are controlled. In this study, we developed an auxin transport model based on actual root cell geometries and carrier subcellular localizations. We tested model predictions using the DII-VENUS auxin sensor in conjunction with state-of-the-art segmentation tools. Our study revealed that auxin efflux carriers alone cannot create the pattern of auxin distribution at the root tip and that AUX1/LAX influx carriers are also required. We observed that AUX1 in lateral root cap (LRC) and elongating epidermal cells greatly enhance auxin's shootward flux, with this flux being predominantly through the LRC, entering the epidermal cells only as they enter the elongation zone. We conclude that the nonpolar AUX1/LAX influx carriers control which tissues have high auxin levels, whereas the polar PIN carriers control the direction of auxin transport within these tissues.


Asunto(s)
Arabidopsis/metabolismo , Ácidos Indolacéticos/metabolismo , Raíces de Plantas/metabolismo , Transporte Biológico , Fracciones Subcelulares/metabolismo
12.
Hepatol Res ; 47(7): 650-657, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27487979

RESUMEN

AIM: Laparoscopic hepatectomy (LH), microwave ablation (MWA), and open hepatectomy (OH) are three widely used methods to treat small hepatocellular carcinoma (HCC). However, few studies have compared the short- and long-term outcomes of these three treatments. The aim of this study was to investigate their effectiveness. METHODS: The data were reviewed from 280 patients with HCCs measuring ≤3 cm (Barcelona Clinic Liver Cancer stage 0 or A) who received LH (n = 133), OH (n = 87), or MWA (n = 60) in our research center from 2005 to 2010. Short-term outcomes included intraoperative blood loss, operation time, and length of hospital stay. The disease-free survival and overall survival rates were analyzed as long-term outcomes. RESULTS: The patients in the MWA and LH groups showed better short-term outcomes compared with those in the OH group. There were no significant differences in overall survival rates among the three treatments. The LH group showed significantly lower recurrence rates than the MWA group (P = 0.0146). CONCLUSIONS: Laparoscopic hepatectomy may be a better option for patients with small HCC located on the liver surface and left lateral lobe. The short-term outcome of MWA is promising, although the high risk of local recurrence after the operation should be considered when planning treatment.

13.
Surg Endosc ; 29(11): 3146-53, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25539696

RESUMEN

BACKGROUND: The aim of this study was to determine whether tumor manipulation enhances cancer cell release from the primary tumor in HCC patients and which surgical approach, open surgery or laparoscopic resection, is superior with respect to preventing tumor cells from scattering in the blood. METHODS: A total of 26 HCC patients were prospectively randomized to receive either open surgery (n = 14) or laparoscopic surgery (n = 12). Blood samples were obtained at three time points: preoperative, postoperative, and 24 h after surgery. The CD45(-)/CD44(+)/CD90(+) cells were obtained and counted using quantitative flow cytometry. The serum levels of interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor (TNF-α) were also compared between the two groups. RESULTS: There was no significant difference between the laparoscopic and open groups in terms of patient characteristics. The levels of CCSCs increased immediately after surgical manipulation, and the laparoscopy group released fewer tumor cells into the blood stream. The amount of CCSCs in both groups decreased to reach a similar level 24 h after surgery. Both IL-6 and IL-8 increased after surgery, and the mean postoperative increases in IL-6 and IL-8 serum levels were significantly less in the laparoscopic group than in the open group. The TNF-α levels showed no differences at any time point. CONCLUSIONS: Our results showed that patients with laparoscopic surgery have lower IL-6, IL-8 secretion and less CTCs, which may suggest an advantage by restricting CTCs release and a preserved immune response. Further studies are needed to investigate the relationship between the number of CCSCs after surgery and long-term survival rates.


Asunto(s)
Carcinoma Hepatocelular/cirugía , Hepatectomía/métodos , Laparoscopía/métodos , Laparotomía/efectos adversos , Neoplasias Hepáticas/cirugía , Células Neoplásicas Circulantes/patología , Adulto , Anciano , Carcinoma Hepatocelular/patología , Femenino , Humanos , Neoplasias Hepáticas/patología , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia/prevención & control
14.
Zhonghua Wai Ke Za Zhi ; 52(6): 405-8, 2014 Jun.
Artículo en Zh | MEDLINE | ID: mdl-25219553

RESUMEN

OBJECTIVE: To evaluate the feasibility, safety and long-term outcomes of laparoscopic repeat hepatectomy for recurrent hepatocellular carcinoma (HCC) following previous resection. METHODS: Between January 2003 and January 2011, 14 patients with recurrent HCC were carefully selected to undergo repeat laparoscopic hepatectomy, among which 9 patients were male, 5 patients were female, and the average age was 54 years. Prior to re-resection, all patients had undergone at least one open hepatectomy for HCC. The perioperative and long-term outcomes of these patients were retrospectively analyzed. RESULTS: Repeat laparoscopic hepatectomy for these 14 patients were successfully performed without major perioperative complications. The mean operative time, intraoperative blood loss and hospital stay were (124 ± 82) minutes, (112 ± 43) ml and (7 ± 4) days, respectively. The mean follow-up period was 23 months (range 14 to 42 months). At the time of follow-up, 11 patients were still alive, among which 3 patients developed recurrent disease and 8 patients remained disease free. One patient died of liver dysfunction at 21 months, and another 2 patients died of tumor recurrence at 17, 31 months, respectively. CONCLUSION: Laparoscopic surgery for recurrent HCC remains a viable option for repeat hepatectomy in selected patients who have undergone open hepatectomy.


Asunto(s)
Carcinoma Hepatocelular/cirugía , Hepatectomía/métodos , Laparoscopía , Neoplasias Hepáticas/cirugía , Adulto , Anciano , Femenino , Estudios de Seguimiento , Humanos , Laparotomía , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/cirugía , Estudios Retrospectivos
15.
J Agric Food Chem ; 71(4): 1845-1851, 2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36655791

RESUMEN

Camptothecin (CPT) is a prominent molecule in natural product research because of its application prospects in medicine and agriculture. In this study, CPT and its derivatives were discovered to be competitive inhibitors of group II and group h insect chitinases, both of which are key components of insect chitinolytic systems. CPT and 7-ethyl-10-hydroxycamptothecin (SN-38) inhibited group II chitinase from Ostrinia furnacalis (OfChtII) with Ki values of 5.1 and 2.0 µM, respectively. Results from tryptophan fluorescence spectroscopy, molecular docking analysis, and molecular dynamics simulations revealed that both CPT and SN-38 inhibit OfChtII-C1 by interacting with solvent-exposed tryptophan residues in a substrate-binding cleft. CPT exhibited high insecticidal activity toward the orthopteran pest Locusta migratoria, possibly because of the midgut metabolism of CPT, with only moderate activities toward lepidopteran pests. Even though SN-38 exhibited much lower insecticidal activities than CPT, it still showed higher inhibitory activity toward chitinase. This study reports a new molecular target of CPT and provides insights into molecular design of CPT-based insecticides against different kinds of pests.


Asunto(s)
Quitinasas , Insecticidas , Irinotecán , Insecticidas/farmacología , Insecticidas/química , Simulación del Acoplamiento Molecular , Quitinasas/genética , Quitinasas/farmacología , Triptófano
16.
Nat Commun ; 14(1): 5235, 2023 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-37640714

RESUMEN

Stable cathodes with multiple redox-active centres affording a high energy density, fast redox kinetics and a long life are continuous pursuits for aqueous zinc-organic batteries. Here, we achieve a high-performance zinc-organic battery by tuning the electron delocalization within a designed fully conjugated two-dimensional hydrogen-bonded organic framework as a cathode material. Notably, the intermolecular hydrogen bonds endow this framework with a transverse two-dimensional extended stacking network and structural stability, whereas the multiple C = O and C = N electroactive centres cooperatively trigger multielectron redox chemistry with super delocalization, thereby sharply boosting the redox potential, intrinsic electronic conductivity and redox kinetics. Further mechanistic investigations reveal that the fully conjugated molecular configuration enables reversible Zn2+/H+ synergistic storage accompanied by 10-electron transfer. Benefitting from the above synergistic effects, the elaborately tailored organic cathode delivers a reversible capacity of 498.6 mAh g-1 at 0.2 A g-1, good cyclability and a high energy density (355 Wh kg-1).

17.
Nat Protoc ; 18(8): 2459-2484, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37460631

RESUMEN

Conducting polymers with conjugated backbones have been widely used in electrochemical energy storage, catalysts, gas sensors and biomedical devices. In particular, two-dimensional (2D) mesoporous conducting polymers combine the advantages of mesoporous structure and 2D nanosheet morphology with the inherent properties of conducting polymers, thus exhibiting improved electrochemical performance. Despite the use of bottom-up self-assembly approaches for the fabrication of a variety of mesoporous materials over the past decades, the synchronous control of the dimensionalities and mesoporous architectures for conducting polymer nanomaterials remains a challenge. Here, we detail a simple, general and robust route for the preparation of a series of 2D mesoporous conducting polymer nanosheets with adjustable pore size (5-20 nm) and thickness (13-45 nm) and controllable morphology and composition via solution-based self-assembly. The synthesis conditions and preparation procedures are detailed to ensure the reproducibility of the experiments. We describe the fabrication of over ten high-quality 2D-ordered mesoporous conducting polymers and sandwich-structured hybrids, with tunable thickness, porosity and large specific surface area, which can serve as potential candidates for high-performance electrode materials used in supercapacitors and alkali metal ion batteries, and so on. The preparation time of the 2D-ordered mesoporous conducting polymer is usually no more than 12 h. The subsequent supercapacitor testing takes ~24 h and the Na ion battery testing takes ~72 h. The procedure is suitable for users with expertise in physics, chemistry, materials and other related disciplines.


Asunto(s)
Nanoestructuras , Polímeros , Polímeros/química , Reproducibilidad de los Resultados , Nanoestructuras/química , Porosidad , Catálisis
18.
Adv Sci (Weinh) ; 10(19): e2301918, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37098637

RESUMEN

Despite the impressive progress in mesoporous materials over past decades, for those precursors having no well-matched interactions with soft templates, there are still obstacles to be guided for mesoporous structure via soft-template strategies. Here, a polyoxometalate-assisted co-assembly route is proposed for controllable construction of superstructured mesoporous materials by introducing polyoxometalates as bifunctional bridge units, which weakens the self-nucleation tendency of the precursor through coordination interactions and simultaneously connects the template through the induced dipole-dipole interaction. By this strategy, a series of meso-structured polymers, featuring highly open radial mesopores and dendritic pore walls composed of continuous interwoven nanosheets can be facilely obtained. Further carbonization gave rise to nitrogen-doped hierarchical mesoporous carbon decorated uniformly with ultrafine γ-Mo2 N nanoparticles. Density functional theory proves that nitrogen-doped carbon and γ-Mo2 N can strongly adsorb polyiodide ions, which effectively alleviate polyiodide dissolving in organic electrolytes. Thereby, as the cathode materials for sodium-iodine batteries, the I2 -loaded carbonaceous composite shows a high specific capacity (235 mA h g-1 at 0.5 A g-1 ), excellent rate performance, and cycle stability. This work will open a new venue for controllable synthesis of new hierarchical mesoporous functional materials, and thus promote their applications toward diverse fields.

19.
Sci Data ; 10(1): 895, 2023 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-38092796

RESUMEN

Small-scale motion detection using non-invasive remote sensing techniques has recently garnered significant interest in the field of speech recognition. Our dataset paper aims to facilitate the enhancement and restoration of speech information from diverse data sources for speakers. In this paper, we introduce a novel multimodal dataset based on Radio Frequency, visual, text, audio, laser and lip landmark information, also called RVTALL. Specifically, the dataset consists of 7.5 GHz Channel Impulse Response (CIR) data from ultra-wideband (UWB) radars, 77 GHz frequency modulated continuous wave (FMCW) data from millimeter wave (mmWave) radar, visual and audio information, lip landmarks and laser data, offering a unique multimodal approach to speech recognition research. Meanwhile, a depth camera is adopted to record the landmarks of the subject's lip and voice. Approximately 400 minutes of annotated speech profiles are provided, which are collected from 20 participants speaking 5 vowels, 15 words, and 16 sentences. The dataset has been validated and has potential for the investigation of lip reading and multimodal speech recognition.

20.
ACS Nano ; 17(20): 20643-20653, 2023 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-37796635

RESUMEN

Here, by introducing polystyrenesulfonate (PSS) as a multifunctional bridging molecule to synchronously coordinate the interaction between the precursor and the structure-directing agent, we developed a mesoporous conductive polymer of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) featuring adjustable size in the range of 105-1836 nm, open nanochannels, large specific surface area (105.5 m2 g-1), and high electrical conductivity (172.9 S cm-1). Moreover, a large-area ultrathin PEDOT:PSS thin film with well-defined mesopores can also be obtained by controllable growth on various functional interfaces. As an example, we demonstrated that the iodine-loaded mesoporous PEDOT:PSS nanospheres can serve as a promising cathode for aqueous zinc-iodine batteries with high specific capacity (241 mAh g-1), excellent rate performance, and superlong 20,000 cycle life. In-depth theoretical calculations and systematic experimental results together reveal that the exposed sulfur- and oxygen-containing functional groups hold strong interactions with iodine species, resulting in effectively anchoring iodine species and inhibiting the shuttling of polyiodide intermediates, thus ensuring the long-term stability of the batteries. This work introduces a member to the family of mesoporous materials as well as porous polymers with versatile applications.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA