RESUMEN
BACKGROUND. Consensus is lacking regarding optimal embolic agents for transcatheter arterial embolization (TAE) of renal angiomyolipomas (AMLs). OBJECTIVE. The purpose of our study was to compare the safety and efficacy of TAE with polyvinyl alcohol (PVA) and TAE with a combination of ethiodized oil (Lipiodol)-bleomycin emulsion and N-butyl cyanoacrylate (NBCA)-Lipiodol emulsion for the treatment of patients with large or symptomatic AMLs. METHODS. This prospective study enrolled patients referred for TAE of a large (> 4 cm) or symptomatic renal AML from July 2007 to December 2018. Patients were randomized to undergo TAE using PVA particles or a combination of Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion. Patients underwent serial clinical follow-up visits and follow-up CT or MRI examinations after TAE. Outcomes were compared between groups. RESULTS. Seventy-eight patients were enrolled. After exclusions, the analysis included 72 patients (15 men, 57 women; mean age, 35.0 years; 51 patients with hematuria, 66 patients with flank pain): 35 patients were randomized to treatment by PVA and 37 were randomized to treatment by a combination of Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion. Complete occlusion of all angiographically visible arterial supply was achieved in all patients. No major adverse event occurred in any patient. The mean follow-up after TAE was 77 ± 45 (SD) months (range, 37-180 months). The frequency of resolution of hematuria after initial TAE without recurrence was greater after treatment by Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion than by PVA (100.0% vs 80.0%, respectively; p = .03). At 12-month follow-up, the frequency of complete resolution of flank pain was higher after treatment by Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion than by PVA (100.0% vs 75.0%, p = .03). Mean reduction in AML volume at 36 months or longer after TAE versus at baseline was greater in patients treated by Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion than in those treated by PVA (98.0% vs 85.7%, respectively; p = .04). The frequency of complete response by modified RECIST (mRECIST) criteria at 36 months or longer after TAE was greater in patients treated by Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion than by PVA (94.6% vs 74.3%, p = .04). The rate of repeat TAE was higher among patients treated by PVA than among those treated by Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion (25.7% vs 8.1%, p = .04). CONCLUSION. Superior outcomes after TAE of AML were achieved using Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion than using PVA. CLINICAL IMPACT. TAE using a combination of Lipiodol-bleomycin emulsion and NBCA-Lipiodol emulsion is a safe and effective treatment option for large or symptomatic AMLs. TRIAL REGISTRATION. Chinese Clinical Trial Registry ChiCTR2100053296.
Asunto(s)
Angiomiolipoma , Embolización Terapéutica , Enbucrilato , Neoplasias Renales , Leucemia Mieloide Aguda , Masculino , Humanos , Femenino , Adulto , Aceite Etiodizado/uso terapéutico , Bleomicina , Estudios Prospectivos , Alcohol Polivinílico/uso terapéutico , Angiomiolipoma/diagnóstico por imagen , Angiomiolipoma/terapia , Emulsiones , Enbucrilato/uso terapéutico , Dolor en el Flanco , Hematuria , Neoplasias Renales/terapia , Neoplasias Renales/tratamiento farmacológico , Embolización Terapéutica/métodos , Resultado del Tratamiento , Leucemia Mieloide Aguda/tratamiento farmacológicoRESUMEN
PURPOSE: To study short-term and long-term outcomes of lower extremity venous stents placed at a single center and to characterize changes in vein diameter achieved by stent placement. MATERIALS AND METHODS: A database of all patients who received lower extremity venous stents between 1996 and 2018 revealed 1,094 stents were placed in 406 patients (172 men, 234 women; median age, 49 y) in 513 limbs, including patients with iliocaval stents (9.4% acute thrombosis, 65.3% chronic thrombosis, 25.3% nonthrombotic lesions). Primary, primary assisted, and secondary patency rates were assessed for lower extremity venous stents at 1, 3, and 5 years using Kaplan-Meier analyses and summary statistics. Subset analyses and Cox regression were performed to identify risk factors for patency loss. Vein diameters and Villalta scores before and up to 12 months after stent placement were compared. Complication and mortality rates were calculated. RESULTS: Primary, primary assisted, and secondary patency rates at 5 years were 57.3%, 77.2%, and 80.9% by Kaplan-Meier methods and 78.6%, 90.3%, and 92.8% by summary statistics. Median follow-up was 199 days (interquartile range, 35.2-712.0 d). Patency rates for the subset of patients (n = 46) with ≥ 5 years of follow-up (mean ± SD 9.1 y ± 3.4) were nearly identical to cohort patency rates at 5 years. Patients with inferior vena cava stent placement (hazard ratio 2.11, P < .0001) or acute thrombosis (hazard ratio 3.65, P < .0001) during the index procedure had significantly increased risk of losing primary patency status. Vein diameters were significantly greater after stent placement. There were no instances of stent fracture, migration, or structural deformities. In patients with chronic deep vein thrombosis, Villalta scores significantly decreased after stent placement (from 15.7 to 7.4, P < .0001). Perioperative mortality was < 1%, and major perioperative complication rate was 3.7%. CONCLUSIONS: Cavo-ilio-femoral stent placement for venous occlusive disease achieves improvement of vein disease severity scores, increase in treated vein diameters, and satisfactory long-term patency rates.
Asunto(s)
Procedimientos Endovasculares/instrumentación , Vena Ilíaca , Extremidad Inferior/irrigación sanguínea , Stents , Vena Cava Inferior , Trombosis de la Vena/terapia , Adulto , Bases de Datos Factuales , Procedimientos Endovasculares/efectos adversos , Procedimientos Endovasculares/mortalidad , Femenino , Humanos , Vena Ilíaca/diagnóstico por imagen , Vena Ilíaca/fisiopatología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Grado de Desobstrucción Vascular , Vena Cava Inferior/diagnóstico por imagen , Vena Cava Inferior/fisiopatología , Trombosis de la Vena/diagnóstico por imagen , Trombosis de la Vena/mortalidad , Trombosis de la Vena/fisiopatologíaRESUMEN
Tactoids are nuclei of an orientationally ordered nematic phase that emerge upon cooling the isotropic phase. In addition to providing a natural setting for exploring chromonics under confinement, we show that tactoids can also serve as optical probes to delineate the role of temperature and concentration in the aggregation behavior of chromonics. For high concentrations, we observe the commonly reported elongated bipolar tactoids. As the concentration is lowered, breaking of achiral symmetry in the director configuration is observed with a predominance of twisted bipolar tactoids. On further reduction of concentration, a remarkable transformation of the director configuration occurs, wherein it conforms to a unique splay-minimizing configuration. Based on a simple model, we arrive at an interesting result that lower concentrations have longer aggregates at the same reduced temperature. Hence, the splay deformation that scales linearly with the aggregate length becomes prohibitive for lower concentrations and is relieved via twist and bend deformations in this unique configuration. Raman scattering measurements of the order parameters independently verify the trend in aggregate lengths and provide a physical picture of the nematic-biphasic transition.
RESUMEN
BACKGROUND: The efficacy and safety of transarterial chemoembolization (TACE) combined with lenvatinib plus programmed cell death protein-1 (PD-1) for unresectable hepatocellular carcinoma (HCC) have rarely been evaluated and it is unknown which factors are related to efficacy. AIM: To evaluate the efficacy and independent predictive factors of TACE combined with lenvatinib plus PD-1 inhibitors for unresectable HCC. METHODS: This study retrospectively enrolled patients with unresectable HCC who received TACE/lenvatinib/PD-1 treatment between March 2019 and April 2022. Overall survival (OS) and progression-free survival (PFS) were determined. The objective response rate (ORR) and disease control rate (DCR) were evaluated in accordance with the modified Response Evaluation Criteria in Solid Tumors. Additionally, the prognostic factors affecting the clinical outcome were assessed. RESULTS: One hundred and two patients were enrolled with a median follow-up duration of 12.63 months. The median OS was 26.43 months (95%CI: 17.00-35.87), and the median PFS was 10.07 months (95%CI: 8.50-11.65). The ORR and DCR were 61.76% and 81.37%, respectively. The patients with Barcelona Clinic Liver Cancer Classification (BCLC) B stage, early neutrophil-to-lymphocyte ratio (NLR) response (decrease), or early alpha-fetoprotein (AFP) response (decrease > 20%) had superior OS and PFS than their counterparts. CONCLUSION: This study showed that TACE/lenvatinib/PD-1 treatment was well tolerated with encouraging efficacy in patients with unresectable HCC. The patients with BCLC B-stage disease with early NLR response (decrease) and early AFP response (decrease > 20%) may achieve better clinical outcomes with this triple therapy.
RESUMEN
Automated concentration gradient generation is one of the most important applications of lab-on-a-chip devices. Digital microfluidics is a unique platform that can effectively achieve digitalized gradient concentration preparation. However, the dynamic range and concentration resolution of the prepared samples heavily rely on the size and the number of effective electrodes. In this work, we report an active-matrix digital microfluidic device with polar coordinate electrode arrangement. The device contains 33 different electrode sizes, generating digital droplets of different volumes. To compare with the conventional rectangular coordinate arrangement with a similar electrode number, this work shows an approximately 19 times resolution enhancement for the achievable concentration gradient. We characterized the stability and uniformity of droplets generated by electrodes of different sizes, and the coefficient of variation of stable droplets was less than 3%. The fluorescent nanomaterial's concentration quantification and glucose concentration characterization experiments were also conducted, and the correlation coefficients for the linearities were all above 0.99.
RESUMEN
We demonstrate trapping and characterization of multiple gold nanospheres with a setup composed of dark field imaging and optical tweezers. The number of trapped nanospheres is quantified by the overall dark-field scattering intensity. The spectra of the scattering intensity show that there is no interparticle coupling among trapped nanospheres when the density of nanospheres in the trap is low enough (less than 10 particles), while the density of nanosphere increases the interparticle coupling of nanospheres becomes obvious. In addition, the trapping potential of a single gold nanosphere is obtained by trapping an ensemble of gold nanospheres.
RESUMEN
An optical bottle method is developed to determine the potential-energy profile of colloidal Rayleigh nanoparticles in an optical trap. The three-dimensional distribution of fluorescent particles in the trap is measured by laser scanning confocal fluorescence microscopy. At sufficiently low concentrations at which interactions between the particles are negligible, the single-particle trapping potential-energy profile is determined from the equilibrium number-density profile by use of the Boltzmann distribution. Fluorescence imaging as well as calculations based on a discrete dipole approximation show that effects due to scattering forces are negligible for polystyrene particles of size less than 10% of the wavelength of the trapping laser, thus justifying the assumption of conservative forces in the equilibrium potential-energy determinations. The new optical bottle method measures the entire two-dimensional trapping-potential profile for an individual nanoparticle without the restriction that only one particle be contained in the trap, thus obviating the need for high laser power.
Asunto(s)
Nanopartículas/química , Pinzas Ópticas , Coloides , Tamaño de la Partícula , Poliestirenos/químicaRESUMEN
We report a method in the framework of surface wave holography to manipulate the electromagnetic wave on the metallic surface for realizing complicated electromagnetic wave transport functionalities in three-dimensional (3D) space. The method allows for direct determination of the metallic surface structure morphology for a given transport functionality, by means of writing desirable object information on the metallic surface via interference with a reference surface wave. We have employed the analytical approach to design and build metallic surface structures that realize arbitrary single-point focusing, arbitrary single-direction beam collimation, and simultaneous two-point focusing of electromagnetic wave in 3D space. Good agreement between numerical simulations and microwave experimental measurements has been found and confirms the power of the method in conceptually understanding and exploiting the surface electromagnetic wave on subwavelength metal structures.
Asunto(s)
Holografía/métodos , Metales/química , Metales/efectos de la radiación , Modelos Químicos , Simulación por Computador , Luz , Dispersión de Radiación , Propiedades de SuperficieRESUMEN
A three-dimensional metamaterial nanostructure for realizing all-optical absorption switching is proposed and investigated. The structure consists of dual metallic layers for allowing near-perfect absorption due to electric and magnetic resonances, and a nonlinear Kerr-dielectric layer for actively manipulating the nanostructure absorption. The finite-difference time-domain simulation results demonstrate that, by adjusting the incident optical intensity, the metamaterial absorption can be flexibly tuned from near unity to zero. The all-optical absorption switching structure can find potential applications in actively integrated photonic circuits for thermal sensing, photo detecting, and optical imaging.
RESUMEN
OBJECTIVE: A large prostate size (>80 âmL) of benign prostatic hyperplasia (BPH) is technically challenging to treat surgically. This study aimed to investigate the safety and efficacy of super-selective prostatic artery embolization (PAE) for the treatment of urinary retention caused by large BPH. METHODS: A total of 21 patients with urinary retention, indwelling urinary catheter, or suprapubic cystostomy as a consequence of giant BPH (prostate volume [PV] â> â80 âmL) who sought treatment between January 2013 and December 2017 were enrolled. A microcatheter (1.9-2.7 Fr) and a "two-step embolization" combining 50-µm and 100-µm polyvinyl alcohol embolization particles were used in all patients. International Prostate Symptom Score (IPSS), quality of life (QoL), PV, and prostate-specific antigen (PSA) were evaluated at 3, 6, and 12 months post-PAE. Clinical success was defined as removal of urinary catheter or suprapubic cystostomy and ability to void spontaneously. RESULTS: The clinical success rate was 95.2% (20/21). Compared with pre-procedural values, IPSS, QoL, PV, and PSA showed statistically significant differences at 3, 6, and 12 months post-PAE (P â< â0.05). There were no serious complications after PAE. CONCLUSIONS: PAE was safe and effective for the treatment of urinary retention caused by large BPH in patients without surgical treatment options.
RESUMEN
OBJECTIVE: To investigate the performance of hybrid angio-CT in preoperative detection and localization for insulinomas. METHODS: Fifty-four postoperative pathology-confirmed patients from April 2015 to March 2017 were retrospectively reviewed; all patients underwent angio-CT with administration of contrast media in SMA, GDA and SA due to negative, inconclusive or controversial findings by several preoperative diagnostic methods including TAUS, CEUS, EUS, ECT, EMRI and DSA. Surgery was used as gold standard for localization of insulinomas; detection sensitivity and localization accuracy of angio-CT were assessed and compared with other preoperative image options. RESULTS: Fifty-six benign insulinomas (mean diameter, 15.8 mm) in 54 patients (18 men and 36 women) were found according to surgical results; the overall detection sensitivity of TAUS, CEUS, EUS, ECT, EMRI and DSA was 21.4, 78.4, 79.2, 70.0, 79.2 and 72.2%, respectively. The overall localization accuracy was 14.3, 58.8, 68.8, 60.0, 75.0 and 44.4%, respectively. A total of 53 tumors were detected by angio-CT, 51 tumors were accurately located, and the overall detection sensitivity and localization accuracy of angio-CT was 94.4 and 90.7%, which was significantly higher than that of all other preoperative diagnostic methods (p < 0.05). No any serious complications occurred during angio-CT. CONCLUSION: Our study indicates the great potential value of angio-CT in the preoperative detection and localization of insulinomas; angio-CT can be used as a preferred invasive diagnostic method.
Asunto(s)
Insulinoma/diagnóstico por imagen , Neoplasias Pancreáticas/diagnóstico por imagen , Cuidados Preoperatorios/métodos , Tomografía Computarizada por Rayos X/métodos , Adulto , Medios de Contraste , Diagnóstico por Imagen/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Imagen Multimodal/métodos , Páncreas/diagnóstico por imagen , Intensificación de Imagen Radiográfica/métodos , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y Especificidad , Adulto JovenRESUMEN
AIMS: To evaluate technical feasibility and treatment results of combined transcatheter arterial chemoembolization (TACE) and radiofrequency ablation (RFA) in single-session for solitary hepatocellular carcinoma (HCC) larger than 7 cm in diameter. METHODS: Institutional review board approved this retrospective study. Written informed consent was obtained from all patients. Between June 2007 and July 2013, 87 patients (75 men, 12 women; mean age, 55.5 years ± 15.0) with solitary HCC with a mean maximum diameter of 9.5 cm ± 2.4 (range, 7.1-13.5 cm) not feasible for surgical resection underwent combined TACE and RFA in a single-session. Immediately following TACE, RFA was performed under fluoroscopy and CB-CT guidance. The primary endpoint was overall survival (OS). The secondary endpoints were technical safety and local tumor progression (LTP) rates. OS and time to progression (TTP) were analyzed with the Kaplan-Meier method. Univariate and multivariate analyses were performed to identify prognostic factors affecting OS and TTP. RESULTS: Technical success of combined TACE and RFA in a single-session was achieved in all patients (100%). On 1-month follow-up MRI, complete response (CR) was observed in 76 of 87 patients (87.4 %), partial response (PR) in 8 and stable disease (SD) in 3 patients. The median follow-up period was 49.5 months (interquartile range, 30.0-70.0 months). The median OS was 39 months (range, 15-86 months). The cumulative OS rates at 1, 3 and 5 years were 100%, 65.5% and 47.5%, respectively. The estimated 1, 3 and 5 year LTP rates were 0 %, 29.9% and 55.2 %, respectively. Univariate and multivariate analyses showed a tumor larger than 10.0 cm (P < 0.05) and presence of portal vein branch invasion (P < 0.05) led to the worst prognosis. No major complications were noted. CONCLUSIONS: Combined use of TACE and RFA in single-session is a safe and effective option in the treatment of patients with solitary large HCC (> 7 cm) not amenable to surgery.
Asunto(s)
Carcinoma Hepatocelular/terapia , Quimioembolización Terapéutica/métodos , Neoplasias Hepáticas/terapia , Ablación por Radiofrecuencia/métodos , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/cirugía , Terapia Combinada , Femenino , Humanos , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/cirugía , Masculino , Persona de Mediana Edad , Vena Porta/patología , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
A new optical method is proposed to investigate the reflectance of structurally coloured objects, such as Morpho butterfly wing scales and cholesteric liquid crystals. Using a reflected-light microscope and a digital single-lens reflex (DSLR) camera, we have successfully measured the two-dimensional reflection pattern of individual wing scales of Morpho butterflies. We demonstrate that this method enables us to measure the bidirectional reflectance distribution function (BRDF). The scattering image observed in the back focal plane of the objective is projected onto the camera sensor by inserting a Bertrand lens in the optical path of the microscope. With monochromatic light illumination, we quantify the angle-dependent reflectance spectra from the wing scales of Morpho rhetenor by retrieving the raw signal from the digital camera sensor. We also demonstrate that the polarization-dependent reflection of individual wing scales is readily observed using this method, using the individual wing scales of Morpho cypris. In an effort to show the generality of the method, we used a chiral nematic fluid to illustrate the angle-dependent reflectance as seen by this method.
RESUMEN
BACKGROUND: Currently, treatment of symptomatic polycystic liver disease (PLD) is still a challenging problem, especially for these patients who are not feasible for surgery. Minimally invasive options such as laparoscopic fenestration and percutaneous cyst aspiration with sclerotherapy demonstrated disappointing results due to multiple lesions. Because the cysts in PLD are mostly supplied from hepatic arteries but not from portal veins, transcatheter arterial embolization (TAE) of the hepatic artery branches that supply the major hepatic cysts can lead to shrinkage of the cyst and liver size, relieve symptoms, and improve nutritional status. This study aimed to evaluate the effectiveness of TAE with a mixture of N-butyl-2-cyanoacrylate (NBCA) and iodized oil for patients with severe symptomatic PLD during a more than 2-year follow-up. METHODS: Institutional review board had approved this study. Written informed consent was obtained from all patients. From February 2007 to December 2014, twenty-three patients (20 women and 3 men; mean age, 49.0 ± 14.5 years) infeasible for surgical treatments underwent TAE. Changes in the abdominal circumferences, volumes of intrahepatic cysts, hepatic parenchyma volume, and whole liver, clinical symptoms, laboratory data, and complications were evaluated after TAE. RESULTS: Technical success was achieved in all cases. No procedure-related major complications occurred. The median follow-up period after TAE was 48.5 months (interquartile range, 30.0-72.0 months). PLD-related severe symptoms were improved remarkably in 86% of the treated patients; TAE failed to benefit in four patients (four patients did not benefit from TAE). The mean maximum abdominal circumference decreased significantly from 106.0 ± 8.0 cm to 87.0 ± 15.0 cm (P = 0.021). The mean intrahepatic cystic volume reduction rates compared with pre-TAE were 36% at 12 months, 37% at 24 months, and 38% at 36 months after TAE (P < 0.05). The mean liver volume reduction rates were 32% at 12 months, 31% at 24 months, and 33% at 36 months (P < 0.05). CONCLUSIONS: TAE with the mixture of NBCA and iodized oil appears to be a safe and effective treatment method for patients with symptomatic PLD, especially for those who are not good candidates for surgical treatments, to improve both hepatic volume and hepatic cysts volume.
Asunto(s)
Quistes/terapia , Embolización Terapéutica/métodos , Hepatopatías/terapia , Adulto , Anciano , Quistes/tratamiento farmacológico , Enbucrilato/uso terapéutico , Femenino , Estudios de Seguimiento , Arteria Hepática/efectos de los fármacos , Arteria Hepática/patología , Humanos , Aceite Yodado/uso terapéutico , Hepatopatías/tratamiento farmacológico , Hepatopatías/patología , Masculino , Persona de Mediana Edad , Resultado del TratamientoRESUMEN
The temperature dependence of the orientational order parameters ãP_{2}(cosß)ã and ãP_{4}(cosß)ã in the nematic (N) and twist-bend nematic (N_{tb}) phases of the liquid crystal dimer CB7CB have been measured using x-ray and polarized Raman scattering. The ãP_{2}(cosß)ã obtained from both techniques are the same, while ãP_{4}(cosß)ã, determined by Raman scattering is, as expected, systematically larger than its x-ray value. Both order parameters increase in the N phase with decreasing temperature, drop across the N-N_{tb} transition, and continue to decrease. In the N_{tb} phase, the x-ray value of ãP_{4}(cosß)ã eventually becomes negative, providing a direct and independent confirmation of a conical molecular orientational distribution. The heliconical tilt angle α, determined from orientational distribution functions in the N_{tb} phase, increases to â¼24^{∘} at â¼15 K below the transition. In the N_{tb} phase, α(T)â(T^{*}-T)^{λ}, with λ=0.19±0.03. The transition supercools by 1.7 K, consistent with its weakly first-order nature. The value of λ is close to 0.25 indicating close proximity to a tricritical point.
RESUMEN
The presumed ground state of a nematic fluid confined in a cylindrical geometry with planar anchoring corresponds to that of an axial configuration, wherein the director, free of deformations, is along the long axis of the cylinder. However, upon confinement of lyotropic chromonic liquid crystals in cylindrical geometries, here we uncover a surprising ground state corresponding to a doubly twisted director configuration. The stability of this ground state, which involves significant director deformations, can be rationalized by the saddle-splay contribution to the free energy. We show that sufficient anisotropy in the elastic constants drives the transition from a deformation-free ground state to a doubly twisted structure, and results in spontaneous symmetry breaking with equal probability for either handedness. Enabled by the twist angle measurements of the spontaneous twist, we determine the saddle-splay elastic constant for chromonic liquid crystals for the first time.
Asunto(s)
Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/metabolismo , Compuestos de Fenilurea/uso terapéutico , Quinolinas/uso terapéutico , Humanos , Sorafenib/uso terapéutico , Factor A de Crecimiento Endotelial Vascular/metabolismo , Receptor 1 de Factores de Crecimiento Endotelial Vascular/metabolismo , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Thermophoresis is an efficient process for the manipulation of molecules and nanoparticles due to the strong force it generates on the nanoscale. Thermophoresis is characterized by the Soret coefficient. Conventionally, the Soret coefficient of nanosized species is obtained by fitting the concentration profile under a temperature gradient at the steady state to a continuous phase model. However, when the number density of the target is ultralow and the dispersed species cannot be treated as a continuous phase, the bulk concentration fluctuates spatially, preventing extraction of temperature-gradient induced concentration profile. The present work demonstrates a strategy to tackle this problem by superimposing snapshots of nanoparticle distribution. The resulting image is suitable for the extraction of the Soret coefficient through the conventional data fitting method. The strategy is first tested through a discrete phase model that illustrates the spatial fluctuation of the nanoparticle concentration in a dilute suspension in response to the temperature gradient. By superimposing snapshots of the stochastic distribution, a thermophoretic depletion profile with low standard error is constructed, indicative of the Soret coefficient. Next, confocal analysis of nanoparticle distribution in response to a temperature gradient is performed using polystyrene nanobeads down to 1e-5% (v/v). The experimental results also reveal that superimposing enhances the accuracy of extracted Soret coefficient. The critical particle number density in the superimposed image for predicting the Soret coefficient is hypothesized to depend on the spatial resolution of the image. This study also demonstrates that the discrete phase model is an effective tool to study particle migration under thermophoresis in the liquid phase.
RESUMEN
AIM: To investigate the therapeutic effect of the hepatic arterial administration of sorafenib in rabbit VX-2 hepatocellular carcinoma (HCC) model. METHODS: Rabbit VX-2 HCC models were established via implanting VX-2 tumors into the livers, and randomly divided into four groups, respectively treated with (1) The hepatic arterial administration of iodized oil alone (TACE-i), (2) The hepatic arterial administration of iodized oil and pharmorubicin (TACE-ip), (3) The hepatic arterial administration of iodized and cis-DDP (TACE-ic), (4) The hepatic arterial administration of iodized and sorafenib (TACE-is). The growth rate and intrahepatic metastasis of implanted VX-2 tumor in each rabbit were measured. Microvessel density (MVD) in the adjacent tissues of implanted VX-2 tumor were estimated by detecting the expression of CD34 and VEGF level in tumor adjacent tissues were also examined by Immunohistochemistry. RESULTS: Compared with other groups, TACE-is treatment group presented a better effect on inhibiting tumor growth rate and intrahepatic metastasis in rabbit VX-2 HCC model. The angiogenesis (assessed by MVD) in the adjacent tissues were suppressed more dramatically in TACE-is treated group. Moreover, TACE-is treatment did not significantly increase the levels of alanine transaminase and creatinine compared to the group with TACE-i treatment. CONCLUSION: The hepatic arterial administration of sorafenib and iodized oil (TACE-is) effectively attenuates tumor growth and intrahepatic metastasis in rabbit VX-2 HCC model without obvious hepatic and renal toxicity. One of the related mechanisms may be due to the inhibition of angiogenesis in the adjacent tissues. Our data indicated that TACE-is may be a secure and effective treatment for HCC.