Shell thickness-induced thermal dependence: highly sensitive core-shell CdSe/ZnS/POSS-based temperature probes.

Fluorescence nanothermometry based on quantum dots is a current research hotspot for novel non-contact temperature monitoring, and is of vital significance for the modulation and design of the sensing properties of sensors. Herein, a design strategy to modulate the temperature-sensing characteristics of quantum dots based on the thickness of a shell is proposed. In this study, CdSe/ZnS quantum dot/POSS-based temperature probe films with varying fluorescence characteristics were developed, and the influence of the ZnS shell on temperature sensing was examined by varying the thickness of the ZnS shell. The temperature dependency, linearity, range of applications, and reversibility of quantum dot thin film probes were all considerably regulated by the ZnS shell, according to research on quantum dot/POSS-based films coated with various shell thicknesses. The CdSe/ZnS temperature probe with 4 monolayers (MLs) stood out among the rest due to its strong thermal stability (at least 5 cycles), large usable temperature range (20-80 °C), and excellent temperature sensitivity (R2 > 0.994). The results demonstrated that the temperature sensing performance of quantum dots was the consequence of the combined effect of multiple temperature response properties induced by the thickness of the shell, and the shell control of quantum dots to optimize the temperature sensing performance was an essential approach for the design of temperature probes. This work demonstrates the great potential of the shell in tuning the temperature sensing performance of quantum dots and provides a viable approach for the design of quantum dot temperature probes.

Detection approach for GEO space objects with a wide-field optical telescope array.

In 2020, Changchun Observatory developed a 280 mm wide-field optical telescope array to improve surveillance of space debris in the geosynchronous belt. There are many advantages including a wide field of view, the ability to observe a large area of sky and high reliability. However, the wide field of view causes a significant number of background stars to appear in the image when photographing space objects, making it difficult to detect them. This research focuses on the precise detection of GEO space objects from images taken by this telescope array in order to position them in large quantities. Our work further investigates the motion feature of an object, namely that the object can be seen as being in a uniform linear motion for a brief length of time. Based on this feature, the belt can be divided into a number of smaller areas and the telescope array scans each smaller area one at a time from east to west. To detect objects in the subarea, a combination of image differencing with trajectory association is used. The image differencing algorithm is used to remove most stars and screen out suspected objects in the image. Next, the trajectory association algorithm is employed to further filter out the real objects among the suspected ones, and the trajectories attributed to the same object are linked. The feasibility and accuracy of the approach were verified by the experiment results. The accuracy rate of trajectory association exceeds 90% and on average, more than 580 space objects can be detected per observation night. Since the J2000.0 equatorial system can accurately describe the apparent position of an object, the object can be detected by using this coordinate system as opposed to the pixel coordinate system.

Is Reaction Acceleration of Microdroplet Chemistry Favorable to Controlling the Enantioselectivity?

Microdroplet chemistry has been proven to amazingly accelerate many chemical and biological reactions in the past 2 decades. Current microdroplet accelerated reactions are predominantly symmetric synthetic but minorly asymmetric synthetic reactions, where stereoselectivity is scarcely concerned. This study selected unimolecular and bimolecular reactions, multicomponent Passerini reactions, and enzymatic ketone reduction as the model reactions to illustrate whether reaction acceleration of microdroplet chemistry is favorable to retaining a chiral center and controlling the enantioselectivity or not. The results illustrated that microdroplet chemistry did not disrupt pre-existing stereogenic centers in chiral starting materials during reactions but did harm to stereospecificity in asymmetric catalysis by chiral catalysts and chiral organic ligands with the exclusion of enzymatic reactions. Our preliminary study reminds us of more cautions to the product enantioselectivity when conducting asymmetric catalysis in microdroplets. We also hope this study may promote more valuable further research on the stereoselectivity of microdroplet chemistry.

Microdroplet Chemistry Accelerating a Three-Component Passerini Reaction for α-Acyloxy Carboxamide Synthesis.

α-Acyloxy carboxamides are important multifunctional natural products that show bioactive and pharmacological activities. Traditional three-component Passerini reactions among isocyanates, aldehydes/ketones, and carboxylic acids for affording α-acyloxy carboxamides suffer from several drawbacks such as long reaction time, high reaction temperature, special reaction devices, etc. Herein, we developed a high-efficiency microdroplet method for accelerating the Passerini reactions by 3 orders of magnitude by comparing with the rate constants in bulk, achieving high-yield and gram-scale (scaling up to 1.91 g for 1 h collection) synthesis of α-acyloxy carboxamides at near room temperature. The Passerini microdroplet method shows a wide scope for a variety of benzoic acids, aryl aldehydes, and isocyanates. Moreover, the Passerini reaction was poorly conducted in aqueous microdroplets but well accelerated in acetonitrile microdroplets with at least 230 times efficiency than on-water Passerini reactions. All results proved it an attractive alternative to classic organic synthesis for the construction of α-acyloxy carboxamides and derivatives.

Analysis of the Impact of Atmospheric Models on the Orbit Prediction of Space Debris.

Atmospheric drag is an important influencing factor in precise orbit determination and the prediction of low-orbit space debris. It has received widespread attention. Currently, calculating atmospheric drag mainly relies on different atmospheric density models. This experiment was designed to explore the impact of different atmospheric density models on the orbit prediction of space debris. In the experiment, satellite laser ranging data published by the ILRS (International Laser Ranging Service) were used as the basis for the precise orbit determination for space debris. The prediction error of space debris orbits at different orbital heights using different atmospheric density models was used as a criterion to evaluate the impact of atmospheric density models on the determination of space-target orbits. Eight atmospheric density models, DTM78, DTM94, DTM2000, J71, RJ71, JB2006, MSIS86, and NRLMSISE00, were compared in the experiment. The experimental results indicated that the DTM2000 atmospheric density model is best for determining and predicting the orbits of LEO (low-Earth-orbit) targets.

Ballistic Coefficient Calculation Based on Optical Angle Measurements of Space Debris.

Atmospheric drag is an important factor affecting orbit determination and prediction of low-orbit space debris. To obtain accurate ballistic coefficients of space debris, we propose a calculation method based on measured optical angles. Angle measurements of space debris with a perigee height below 1400 km acquired from a photoelectric array were used for orbit determination. Perturbation equations of atmospheric drag were used to calculate the semi-major-axis variation. The ballistic coefficients of space debris were estimated and compared with those published by the North American Aerospace Defense Command in terms of orbit prediction error. The 48 h orbit prediction error of the ballistic coefficients obtained from the proposed method is reduced by 18.65% compared with the published error. Hence, our method seems suitable for calculating space debris ballistic coefficients and supporting related practical applications.

Development of nomogram models of inflammatory markers based on clinical database to predict prognosis for hepatocellular carcinoma after surgical resection.

BACKGROUND: Inflammation plays a significant role in tumour development, progression, and metastasis. In this study, we focused on comparing the predictive potential of inflammatory markers for overall survival (OS), recurrence-free survival (RFS), and 1- and 2-year RFS in hepatocellular carcinoma (HCC) patients. METHODS: A total of 360 HCC patients were included in this study. A LASSO regression analysis model was used for data dimensionality reduction and element selection. Univariate and multivariate Cox regression analyses were performed to identify the independent risk factors for HCC prognosis. Nomogram prediction models were established and decision curve analysis (DCA) was conducted to determine the clinical utility of the nomogram model. RESULTS: Multivariate Cox regression analysis indicated that the prognostic nutritional index (PNI) and neutrophil-to-lymphocyte ratio (NLR) were independent prognostic factors of OS, and aspartate aminotransferase-to-platelet ratio (APRI) was a common independent prognostic factor among RFS, 1-year RFS, and 2-year RFS. The systemic inflammation response index (SIRI) was an independent prognostic factor for 1-year RFS in HCC patients after curative resection. Nomograms established and achieved a better concordance index of 0.772(95% CI: 0.730-0.814), 0.774(95% CI: 0.734-0.815), 0.809(95% CI: 0.766-0.852), and 0.756(95% CI: 0.696-0.816) in predicting OS, RFS, 1-year RFS, and 2-year RFS respectively. The risk scores calculated by nomogram models divided HCC patients into high-, moderate- and low-risk groups (P < 0.05). DCA analysis revealed that the nomogram models could augment net benefits and exhibited a wider range of threshold probabilities in the prediction of HCC prognosis. CONCLUSIONS: The nomograms showed high predictive accuracy for OS, RFS, 1-year RFS, and 2-year RFS in HCC patients after surgical resection. The nomograms could be useful clinical tools to guide a rational and personalized treatment approach and prognosis judgement.

A pressure-driven capillary electrophoretic system with injection valve sampling.

To improve repeatability and efficiency and to simplify the operation procedure of capillary electrophoresis (CE), a pressurized CE system (p-CE) with injection valve sampling was developed. It consisted of one high-pressure pump, a six-port injection valve, a PEEK cross, a separation and back pressure capillary, an ultraviolet-visible detector and a high voltage power supply. The pressure-driven flow ranging from 4.5 nL min(-1) to 0.81 µL min(-1) in the separation capillary was produced by splitting to the flow from the high-pressure pumps (0.005-0.4 mL min(-1)). Nano-volume sample injection (<10 nL) was conducted by a micro-volume rotary injector (0.5-5 µL) with flow splitting. In the p-CE system, the new commercial capillary could be directly used without any wash, and the capillary-flush process between runs was also eliminated. In this case, the analytes were driven toward the outlet of the separation capillary by the pressurized flow, the electric field force and minute electroosmotic flow, and they were separated owing to the electrophoretic mobility. The p-CE system allows for the independent variation of the pressurized flow rate and electrical field and electrophoretic separation of good repeatability (below 3%) under high electrical fields (500-1000 V cm(-1)) and flow rate gradient modes. The feasibility of the p-CE system in real analysis was demonstrated by iodate quantification in iodized table salts. The separation of iodide and iodate was realized within 0.3 min, proving its high analytical speed.

Catalyst-Free Accelerated Three-Component Synthesis of Betti Bases in Microdroplets.

Due to their important roles in medicine and asymmetric metal catalysis, the formation of Betti bases has attracted wide interest in organic chemical community. Traditional multicomponent reaction methods for synthesizing Betti bases normally require long reaction times under harsh conditions (high temperature, microwave or ultrasonic irradiation, etc.) in the presence of various catalysts. In this study, we developed a mild, highly efficient and environmentally friendly method to synthesize Betti bases without the use of any catalysts in microdroplets. The Betti reaction was accelerated by 6.53×103 in microdroplets by comparing the measured rate constant in bulk. Fifteen Betti bases were synthesized by the microdroplet method using a variety of aldehydes, naphthols and amines with 68-98 % yields at a scaled-up amount of 1.9 g h-1 . Overall it is an attractive alternative to classic organic synthesis for the construction of Betti bases and derivatives.

Suzuki C-C Coupling in Paper Spray Ionization: Microsynthesis of Biaryls and High-Sensitivity MS Detection of Aryl Bromides.

Suzuki-Miyaura cross-coupling is one of the most powerful strategies for constructing biaryl compounds. However, classic Suzuki-Miyaura coupling suffers from hour-scale reaction time and competitive protodeboronation. To address these problems, a mild nonaqueous potassium trimethylsilanolate (TMSOK)-assisted Suzuki-Miyaura coupling strategy was designed for the microsynthesis of biaryls in paper spray ionization (PSI). Due to the acceleration power facilitated by microdroplet chemistry in reactive PSI, the microsynthesis of biaryls by reactive PSI was accomplished within minutes with comparable yields to the bulk, showing good substrate applicability from 32 Suzuki-Miyaura reactions of aryl bromides and aryl boronic acid/borates bearing different substituents. Based on the above TMSOK-assisted Suzuki-Miyaura coupling strategy, we further developed a high-sensitivity and selective PSI mass spectrometry (MS) method for quantitative analysis of aryl bromides, a class of environmentally persistent organic pollutants that cannot be directly detected by ambient mass spectrometry due to their low ionization efficiency. In situ derivatization of aryl bromides was achieved with aryl borates bearing quaternary ammonium groups in PSI. The proposed PSI-MS method shows good linearity over the 0.01-10 µmol L-1 range with low detection limits of 1.8-4.8 nmol L-1 as well as good applicability to the rapid determination of six aryl bromides in three environmental water samples. The proposed PSI-MS method also shows good applicability to brominated flame retardants (polybrominated diphenyls/diphenyl esters). Overall, this study provides a simple, rapid, low-cost, high-sensitivity, and high-selectivity strategy for trace aryl bromides and other brominated pollutants in real samples with minimal/no sample pretreatment.

Nomogram for the Preoperative Prediction of the Macrotrabecular-Massive Subtype of Hepatocellular Carcinoma.

Background: The macrotrabecular-massive subtype of hepatocellular carcinoma (MTM-HCC) is an aggressive histological type and results in poor prognosis. We developed a nomogram model based on laboratory results to predict the presence of MTM-HCC. Methods: A total of 357 HCC patients who underwent radical surgery between January 2015 and December 2020 at Ningbo Medical Center Lihuili Hospital were grouped according to histological type. After propensity score matching (PSM), 267 patients were divided into MTM-HCC (n = 76) and non-MTM-HCC (n = 191) groups. A LASSO regression analysis model was used to select predictive factors. Finally, a nomogram for predicting the presence of MTM-HCC was established. Decision curve analysis (DCA) was conducted to determine the clinical usefulness of the nomogram model by quantifying the net benefits along with the increase in threshold probabilities. Results: The 1-, 3-, and 5-year disease-free survival (DFS) and overall survival (OS) rates for MTM-HCC were 60.0%, 36.0%, 32.4% and 92.1%, 68.7%, 52.2%, respectively. Survival analysis indicated that the probabilities of achieving DFS and OS were significantly worse in the MTM-HCC group than in the non-MTM-HCC group (P < 0.05). The nomogram model that included AST levels, PT and AFP levels achieved a better C-index of 0.723 (95% CI: 0.659-0.787). DCA revealed that the nomogram model could lead to net benefits and exhibited a wider range of threshold probabilities in the prediction of MTM-HCC. Conclusion: The nomogram model included AST, PT and AFP could achieve an optimal performance in the preoperative prediction of MTM-HCC.

Comparison of the short-term outcomes of open and laparoscopic hepatectomy in the treatment of recurrent hepatocellular carcinoma: a single-center retrospective study.

Background: To retrospectively analyze the short-term outcomes between open hepatectomy (OH) and laparoscopic hepatectomy (LH) in the treatment of recurrent hepatocellular carcinoma (HCC). The objective is to develop the optimal surgical method for patients with recurrent liver cancer after operation. Methods: We retrospectively reviewed the data of 165 HCC patients whose cancer recurred after hepatectomy between January 2015 and March 2021 at our medical center. According to the inclusion and exclusion criteria, a total of 74 patients were eventually enrolled in this study. Results: Tumors located in S1, S7, or S8 and larger tumor diameters were more frequent in the OH group, and the difference was statistically significant. Furthermore, there were notable differences between the LH and OH groups in terms of intraoperative blood loss (140.00 vs. 348.68 mL, P<0.001), mean operation time (150.95 vs. 203.28 min, P=0.024), and mean postoperative hospital stay (6.76 vs. 11.28 days, P=0.014). There were no statistically significant differences in the remaining characteristics between the two groups. There was no significant difference in recurrence-free survival and overall survival between the two groups. Conclusions: Compared with OH, LH can significantly reduce the amount of intraoperative blood loss and shorten the operation time and postoperative hospital stay. At the same time, laparoscopic surgery may be a better surgical approach for patients with tumors of smaller diameter located in segments 2 to 6.

A High-Similarity Modeling Method for Low-Porosity Porous Material and Its Application in Bearing Cage Self-Lubrication Simulation.

The porous oil-containing cage achieves the storage, spillage, and suction of lubricating oil by its micro-pore structure, thus ensuring the self-lubricating performance of the bearing. Carrying out fast and accurate modeling of the cage microscopic pore structure is the key to the analysis of the self-lubricating mechanism of bearings. In response to the issues where current modeling methods of porous materials have a low similarity of pore distribution, morphology, structure, and size characteristics, and the transition of pore surfaces is sharp, this paper proposed a modeling method of a highly similar micro-pore structure based on the idea of median filtering, the quartet structure generation set (QSGS), and the slice method. By extracting and analyzing the pore characteristics of the porous model and comparing them with the experimental results of CT scanning, the advantages of the modeling method in terms of morphology and pore connectivity were verified. Finally, by carrying out simulation analysis of the centrifugal force of oil splashing and capillary oil absorption on the constructed model by combining the parameters of porous structures such as porosity and tortuosity, the advantages of the modeling method in the construction of the porous model and multi-physical field analysis were further verified.

Flow Mechanism Characterization of Porous Oil-Containing Material Base on Micro-Scale Pore Modeling.

The self-lubricating effect of the porous oil-containing cage is realized by storing and releasing lubricants through its internal micro-scale pore structure. The internal flow and heat transfer process in the micron-submicron pore structure is crucial to the self-lubricating mechanism of the porous oil-containing cage. To this end, a new modeling method of porous cage was proposed based on random seeds theory, and the local two-dimensional models of porous cage with different micro-scale pore structure were established. The multiphysics coupling simulation analysis of lubricating oil inside the porous cage with the effect of centrifugal force and thermal expansion was carried out based on the COMSOL Multiphysics platform. In order to characterize the micro-scale pore structure, new structural parameter indicators, such as relative surface perimeter, effective porosity, tortuosity and fluid properties related to the internal flow process, were all extracted from the above models. Combing with the Hagen-Poiseuille equation, a flow resistance model of oil flow inside the porous oil-containing cage was obtained. Finally, comparison of simulation results and analytical solutions of the micro-scale resistance model was carried out to verify the correctness of the micro-scale resistance model. The work provides a new direction for the study of the lubrication mechanism of the porous oil-containing cage.

Surgical Treatment of Postoperative Abdominal Metastases of Hepatocellular Carcinoma: 10-Year Experience in a Single Center.

OBJECTIVE: The significance of surgical treatment was analyzed by retrospectively collecting data on the re-resection of intra-abdominal metastases after hepatocellular carcinoma (HCC) surgery in our center over the past 10 years. METHODS: The clinical and pathological data of 15 patients who developed intra-abdominal metastases after HCC resection and underwent re-resection from January 2010 to January 2020 were collected to analyze the patients' characteristics and prognosis. RESULTS: Of the 15 cases of abdominal metastasis, the majority (8 cases) had greater omental metastasis. There were 4 cases of mesenteric metastases, 1 case of abdominal wall metastasis, 1 case of mesenteric plus rectal wall metastasis, and 1 case of colon and mesenteric metastasis. The 1-year, 3-year, and 5-year disease-free survival (DFS) rates were 31.1%, 23.3%, and 11.7%, respectively. The 1-year, 3-year, and 5-year overall survival rates were 93.3%, 28.7%, and 19.1%, respectively. Three patients are currently surviving disease-free, with survival times of 130.4 months, 43.3 months, and 9.4 months, respectively. CONCLUSION: Although the current guidelines do not recommend surgical resection as the preferred treatment for postoperative abdominal metastases of HCC, surgical resection is recommended for patients with limited or solitary metastasis in the abdominal cavity.

Simultaneous multi-elemental speciation of As, Hg and Pb by inductively coupled plasma mass spectrometry interfaced with high-performance liquid chromatography.

This work establishes a hyphenated methodology coupling HPLC with ICP-MS for simultaneous speciation analysis of arsenic, mercury and lead for the first time. Four arsenicals (As(III), DMA, MMA and As(V)), four mercurials (Hg(II), MeHg, EtHg and PhHg) and three lead compounds (Pb(II), TML and TEL) were simultaneously analyzed within only 8 min with acceptable resolution (2.0-8.2 for As, 1.6-6.1 for Hg and 2.7-4.0 for Pb). The detection limits were 0.036-0.20 for As-species, 0.023-0.041 for Hg-species, and 0.0076-0.14 µg L-1 for Pb-species. The developed method was applied for the measurement of five lotus seed samples, indicating the presence of DMA (19.6-28.2 µg kg-1), TML (1.4-2.9 µg kg-1), MeHg (1.2-4.8 µg kg-1) and EtHg (0.8-2.2 µg kg-1). This method provides a promising tool for studying the toxic, metabolic and bioavailable behaviors of arsenic, mercury and lead.

Multi-particle frits for packed capillary columns in electrochromatographic use.

Further development of capillary electrochromatography (CEC) is to some extent restricted by column technology. Packed capillary columns are most commonly used in CEC because of higher sample capacity and higher sensitivity than open tubular columns, and better reproducibility and uniformity than monolithic columns. Fritting is the core component for the fabrication of packed capillary columns. Therefore various fritting technologies attract continuous attention from analytical community. A convenient fritting method was developed in this study. In contrast to the reported single-particle fritting, this method applies a multi-particle fritting technology to hold stationary phase in capillary columns. Several large porous particles smaller than the column internal diameter were tapped in and immobilized in inlet and outlet of the packing material bed due to direct and indirect keystone effect. Except the smallest permeability by the sintered frit and the lowest breaking pressure by the single-particle frit, EOF mobility and peak dispersion of the multi-particle frit were at the same levels with the formers. In addition, all the three frits avoided bubble formation. It demonstrated that the multi-particle frits met the general requirements of permeability, mechanical resistance and efficiency for packing capillary microcolumns as well as the sintered frits and the single-particle frits. Thus, peak efficiency around 4.3 µm plate height (approximately 232,560 plates per meter) was obtained by multi-particle fritted capillary columns with electrokinetic packing, compared to 6.5 µm plate height by single-particle fritted columns with slurry pressure packing. In particular, the multi-particle fritting was simpler, faster, and more reproducible than the sintered fritting, and the multi-particle fritting was suitable to pack capillary columns of various capillary bore sizes owing to rich commercial resources of fritting particles of various diameters. Multi-particle fritted columns offered satisfactory run-to-run and column-to-column reproducibilities for retention factor, plate height and peak area (precisions of 4.1-9.3% for 10 replicated columns, and precisions of 0.9-3.1% for 30 replicated trials). They also had consistent CEC performance (differences of 1.1-3.9% between the first and 31 st day) during a lifetime more than one month. Application examples in packing capillary columns of 75 and 100 µm i.d. and CEC analysis of sixteen polycyclic aromatic hydrocarbons prove the diversity and reliability of the multi-particle fritting in column technology.

Migration of phthalates from plastic packages to convenience foods and its cumulative health risk assessments.

Convenience foods are commonly packaged with plastic materials. Many of the phthalate plasticizers (PAEs) in the packages may migrate into the foods and cause health hazards. In the present study, the contents of some PAEs were analyzed in 283 convenience foods and the plastic packaging materials. Health hazards were assessed for infants, children and young people. The contents of diethylhexyl phthalate (DEHP), found in the samples rich in fat, ranged from below the limit of detection to 5.23 mg/kg. The content of dibutylphthalate (DBP) ranged from 0.511 mg/kg in meat to 2.54 mg/kg in cake. The content of PAEs in convenience foods near their expiration date was much higher than that of just manufactured packages. Children are more prone to be adversely affected by the PAEs than the adults. In addition, females are more sensitive to the PAEs than males.

Use of ion-pairing reagent for improving iodine speciation analysis in seaweed by pressure-driven capillary electrophoresis and ultraviolet detection.

This study achieved resolution improvement for iodine speciation in the presence of an ion-pairing reagent by a pressure-driven capillary electrophoresis (CE) system. Addition of 0.01mM tetrabutyl ammonium hydroxide (TBAH) as the ion-pairing reagent into the electrophoretic buffer resulted in the complete separation of four iodine species (I(-), IO3(-), mono-iodothyrosine-MIT and di-iodothyrosine-DIT), because of the electrostatic interaction between TBAH and the negatively charged analytes. A +16kV separation voltage was applied along the separation capillary (50µm i.d., 80cm total and 60cm effective) with the inlet grounded. The detection wavelength was fixed at 210nm, and the pressure-driven flow rate was set at 0.12mLmin(-1) with an injected volume of 2µL. The optimal electrolyte consisted of 2mM borate, 2mM TBAH and 80% methanol with pH adjusted to 8.5. Baseline separation of iodine species was achieved within 7min. The detection limits for I(-), IO3(-), MIT and DIT were 0.052, 0.040, 0.032 and 0.025mgL(-1), respectively. The relative standard deviations of peak heights and areas were all below 3% for 5mgL(-1) and 5% for 1mgL(-1). Application of the proposed method was demonstrated by speciation analysis of iodine in two seaweed samples. The developed method offered satisfactory recoveries in the 91-99% range and good precisions (<5%). Good agreement between the determined values by the proposed CE method and the HPLC-ICP-MS method was also obtained. All results proved its great potential in routine analysis of iodine speciation in environmental, food and biological samples.

Suppressor of Zeste 12 homolog RNA interference inhibits retinoblastoma cell invasion.

Suppressor of Zeste 12 homolog (SUZ12) is known to regulate tumor phenotype through altering gene expression, with an important regulatory role in tumor genesis and development. SUZ12 has been widely investigated; however, no studies regarding the role of the SUZ12 gene in retinoblastoma (RB) have been conducted. In this study, SUZ12 small interfering (si)RNA was transfected into SO-RB50 human RB cells. The influence of SUZ siRNA on RB cell invasion was detected using a soft agar colony forming assay and a Transwell cabin model. The effect of the SUZ12 siRNA on the expression levels of the associated proteins, vascular endothelial growth factor (VEGF), matrix metalloproteinase (MMP)-9 and MMP-2, was detected by western blotting. The number of cell clones was found to be reduced by the siRNA in a dose-dependent manner, and the number of cells that had permeated through the filter membrane was reduced following transfection with the siRNA. SUZ12 inhibition resulted in a marked reduction in VEGF, MMP-2 and MMP-9 expression levels (0.26±0.04, 0.16±0.02 and 0.12±0.02, respectively) compared with the levels in the non-transfected group (0.80±0.10, 0.94±0.16 and 1.15±0.18, respectively) (P<0.01). In conclusion, SUZ12 siRNA inhibited cell invasion and the expression of VEGF, MMP-2 and MMP-9 in SO-RB50 retinoblastoma cells.