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BACKGROUND: The emergence of robotic surgical systems compensated for the technological shortcomings of laparoscopic approaches. However, whether robotic gastrectomy (RG) has better perioperative outcomes and survival than laparoscopic gastrectomy (LG) for gastric cancer is still unclear but increasingly drawing attention. MATERIALS AND METHODS: In this systematic review and meta-analysis, we searched the PubMed, EMBASE, Web of Science, and Cochrane Library as of January 20, 2024 and referenced list of eligible articles for all published studies comparing RG and LG for patients with gastric cancer, Data on study characteristics, individual characteristics, and outcome parameters were extracted. The quality of studies was assessed using the Revised Cochrane risk-of-bias 2 tool and the risk of bias in non-randomized studies of interventions tool. The main outcome measures were overall survival (OS) and disease-free survival (DFS). RESULTS: We identified 3641 articles, of which 72 studies (30081 patients) were included in the meta-analysis. Compared with LG, RG was associated with higher OS [hazard ratio (HR)=0.89, 95% CI=0.83 to 0.96), lower rate of overall postoperative complications [odds ratio (OR)=0.77, 95% CI=0.71 to 0.84], longer operating time [mean difference (MD)=35.53, 95% CI=29.23 to 41.83], less estimated blood loss (MD=-37.45, 95% CI=-46.24 to -28.67), a higher number of retrieved lymph nodes (MD=1.88, 95% CI=0.77 to 3.00), faster postoperative recovery, and lower rate of conversion (OR=0.44, 95% CI=0.36 to 0.55). Mortality and DFS were not significantly different between the two groups. The subgroup of meta-analysis results also showed the advantages of robotic surgery over laparoscopic surgery in intracorporeal reconstruction, total gastrectomy, â /â ¡ stage, and BMI≥25, especially for patients with stage â /â ¡, there is better overall survival and disease-free survival. CONCLUSION: Our findings point to robotic surgery having great benefits compared with laparoscopic surgery in gastric cancer. Our study may help inform decision-making in applying robotic surgical systems to clinical treatment.
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Akkermansia muciniphila (A. muciniphila), a probiotic, has been linked to macrophage phenotypic polarization in different diseases. However, the role and mechanisms of A. muciniphila in regulating macrophage during ulcerative colitis (UC) are not clear. This research aimed to examine the impact of A. muciniphila on dextran sulfate sodium (DSS)-induced acute colitis and elucidate the underlying mechanism related to macrophage phenotypic polarization. A. muciniphila inhibited weight loss, increased disease activity index, and ameliorated inflammatory injury in colonic tissues in mice induced with DSS. Furthermore, A. muciniphila reduced macrophage M1 polarization and ameliorated epithelial barrier damage in colonic tissues of DSS-induced mice through inhibition of histone deacetylase 5 (HDAC5). In contrast, the effect of A. muciniphila was compromised by HDAC5 overexpression. HDAC5 deacetylated H3K9ac modification of the disabled homolog 2 (DAB2) promoter, which led to repressed DAB2 expression. DAB2 overexpression blocked HDAC5-induced pro-inflammatory polarization of macrophages, whereas knockdown of DAB2 resulted in the loss of effects of A. muciniphila against colonic injury in DSS-induced mice. Taken together, A. muciniphila-induced loss of HDAC5 hampered the deacetylation of DAB2 and enhanced the expression of DAB2. Our findings propose that A. muciniphila may be a possible probiotic agent for alleviating DSS-induced acute colitis.
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Polysaccharide-stabilized emulsions have received extensive attention, but emulsifying activity of polysaccharides is poor. In this study, konjac glucomannan (KGM) and tannic acid (TA) complex (KGM-TA) was prepared via non-covalent binding to increase the polysaccharide interfacial stability. The emulsifying stabilities of KGM-TA complex-stabilized emulsions were analyzed under different TA concentrations and oil fractions. The results indicated that hydrogen bonds and hydrophobic bonds were the main binding forces for KGM-TA complex, which were closely related to TA concentrations. The interfacial tension of KGM-TA complex decreased from 20.0 mN/m to 13.4 mN/m with TA concentration increasing from 0 % to 0.3 %, indicating that TA improved the interfacial activity of KGM. Meanwhile, the contact angle of KGM-TA complex was closer to 90° with the increasing TA concentrations. The emulsifying stability of KGM-TA complex-stabilized emulsions increased in an oil mass fraction-dependent manner, reaching the maximum at 75 % oil mass fraction. Moreover, the droplet sizes of KGM-TA complex-stabilized high-internal-phase emulsions (HIPEs) decreased from 82.7 µm to 44.7 µm with TA concentration increasing from 0 to 0.3 %. Therefore, high TA concentrations were conducive to the improvement of the emulsifying stability of KGM-TA complex-stabilized HIPEs. High oil mass fraction promoted the interfacial contact of adjacent droplets, thus enhancing the non-covalent binding of KGM molecules at the interfaces with TA as bridges. Additionally, the high TA concentrations increased the gel network density in the aqueous phase, thus enhancing the emulsifying stability of emulsions. Our findings reveal the mechanisms by which polysaccharide-polyphenol complex stabilized HIPEs. Therefore, this study provides theoretical basis and references for the developments of polysaccharide emulsifier with high emulsifying capability and high-stability emulsions.
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Mananos , Polifenoles , Polisacáridos , Emulsiones/química , Tamaño de la Partícula , Polisacáridos/químicaRESUMEN
The duration of storage significantly influences the quality and market value of Qingzhuan tea (QZT). Herein, a high-resolution multiple reaction monitoring (MRMHR) quantitative method for markers of QZT storage year was developed. Quantitative data alongside multivariate analysis were employed to discriminate and predict the storage year of QZT. Furthermore, the content of the main biochemical ingredients, catechins and alkaloids, and free amino acids (FAA) were assessed for this purpose. The results show that targeted marker-based models exhibited superior discrimination and prediction performance among four datasets. The R2Xcum, R2Ycum and Q2cum of orthogonal projection to latent structure-discriminant analysis discrimination model were close to 1. The correlation coefficient (R2) and the root mean square error of prediction of the QZT storage year prediction model were 0.9906 and 0.63, respectively. This study provides valuable insights into tea storage quality and highlights the potential application of targeted markers in food quality evaluation.
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Camellia sinensis , Almacenamiento de Alimentos , Metabolómica , Té , Té/química , Análisis Multivariante , Camellia sinensis/química , Análisis Discriminante , Catequina/análisis , Catequina/química , Aminoácidos/análisis , Aminoácidos/química , Alcaloides/análisis , Alcaloides/química , Cromatografía Líquida de Alta Presión , Extractos Vegetales/química , Extractos Vegetales/análisisRESUMEN
It's generally believed that the longer the storage, the better the quality of dark tea, but the chemical differences of Qingzhuan tea (QZT) with different storage years is still unclear. Herein, in this work, an untargeted metabolomic approach based on SWATH-MS was established to investigate the differential compounds of QZT with 0-9 years' storage time. These QZT samples were roughly divided into two categories by principal component analysis (PCA). After orthogonal projections to latent structures discriminant analysis (OPLS-DA), 18 differential compounds were putatively identified as chemical markers for the storage year variation of QZT. Heatmap visualization showed that the contents of catechins, fatty acids, and some phenolic acids significantly reduced, flavonoid glycosides, triterpenoids, and 8-C N-ethyl-2-pyrrolidinone-substituted flavan-3-ols (EPSFs) increased with the increase of storage time. Furthermore, these chemical markers were verified by the peak areas corresponding to MS2 ions from SWATH-MS. Based on the extraction chromatographic peak areas of MS and MS2 ions, a duration time prediction model was built for QZT with correlation coefficient R2 of 0.9080 and 0.9701, and RMSEP value of 0.85 and 1.24, respectively. This study reveals the chemical differences of QZT with different storage years and provides a theoretical basis for the quality evaluation of stored dark tea.
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Catequina , Té , Té/química , Flavonoides/análisis , Metabolómica/métodos , Catequina/análisis , IonesRESUMEN
The interaction mechanism between nanoliposomes (NL) and a soybean protein isolate (SPI) was investigated via the complexation between NL and two major components of SPI, i.e., ß-conglycinin (7S) and glycinin (11S). The endogenous fluorescence emissions of 7S and 11S were statically quenched after complexation with NL, and the polarity of the SPI fluorophore increased. The interaction between NL and SPI was exothermic and spontaneous, 7S/11S secondary structures were altered, and more hydrophobic groups were exposed on protein surfaces. Moreover, the NL-SPI complex had a large zeta potential to attain system stability. Hydrophobic forces and hydrogen bonds played vital roles in the interaction between NL and 7S/11S, and a salt bridge was also involved in the NL-11S interaction. The binding characteristics between NL and 7S/11S were chiefly governed by the protein characteristics, such as amino acid composition, surface hydrophobicity, and advanced structure. These findings could deepen the understanding of the interaction mechanism between NL and SPI.
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Globulinas , Proteínas de Soja , Proteínas de Soja/química , Globulinas/química , Antígenos de Plantas/química , Proteínas de Almacenamiento de Semillas/química , Glycine max/químicaRESUMEN
This paper investigated the effects of Lentinus edodes stipes insoluble dietary fiber (LESIDF, 0%-3.0%) on the quality and microscopic properties of pork myofibrillar protein (MP) gels. The results showed that the water holding capacity and gel strength of composite gels enhanced with increasing LESIDF (1.0%-2.5%), and reached the maximum at the level of 2.5%-3.0%. Disulfide and non-disulfide covalent bonds were major chemical forces maintaining the 3D network of LESIDF-MP composite gels. LESIDF also promoted the formation of ionic and hydrogen bonds, confirmed by the self-assembly of ß-sheets to α-helices, leading to a compact gel network structure. The observation of paraffin section revealed that LESIDF could capture more water molecules in gels, which was consistent with the transformation of free water to immobilized water. Overall, the optimal addition of LESIDF was 2.5%-3.0%, which provided a good strategy for LESIDF as an agricultural by-product to improve the quality of gel meat products.
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Carne de Cerdo , Carne Roja , Hongos Shiitake , Animales , Porcinos , Carne Roja/análisis , Proteínas Musculares/química , Agua/química , Reología , Geles/química , Fibras de la Dieta/análisis , Miofibrillas/químicaRESUMEN
The poor interfacial stability of protein-stabilized high internal phase Pickering emulsions (HIPEs) is a major hurdle to realize their practical applications in food processing. The emulsifying stability is not only related to the protein itself, but also dependent upon the oil phases. In this study, four plant-based oils were studied to understand their respective effects on the interfacial stability of HIPEs prepared by ovalbumin (OVA) and ovalbumin-tannic acid complex (OVA-TA). Our findings revealed that the interfacial activities were closely related to the physicochemical properties of the oil phase, such as the number of carboncarbon double bonds in the unsaturated fatty acids, melting point, and polarity. The emulsifying abilities were ranked as palm oil > soybean oil > olive oil > perilla oil. OVA-TA stabilized HIPEs exhibited excellent emulsifying stability compared with free OVA stabilized ones. This work provided a unique insight into understanding the interfacial stabilization mechanisms for protein-stabilized HIPEs with different kinds of oil phases.
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Aceites de Plantas , Taninos , Emulsiones/química , Ovalbúmina , Tamaño de la Partícula , CarbonoRESUMEN
OBJECTIVE: Robotic surgery has been increasingly used worldwide owing to its advanced features. However, the significant benefits of robotic total gastrectomy (RTG) over laparoscopic total gastrectomy (LTG) have yet to be demonstrated. We conducted a prospective cohort study to compare the safety and efficacy of robotic and laparoscopic total gastrectomy (LTG) with D2 lymphadenectomy for AGC. METHODS: Between March 26, 2018 and July 30, 2021, 155 patients between 18 and 80 years of age with locally advanced gastric cancer (cT2-4a, N0/+, M0) were enrolled. The perioperative outcomes within 30 days after surgery were compared between the RTG (n = 69) and LTG (n = 73) groups on a per-protocol (PP) basis. Postoperative complications were evaluated according to the Clavien-Dindo classification. RESULTS: The overall postoperative morbidity rate was 21.74% in the RTG group and 28.77% in the LTG group with no significant difference (P = 0.44), RTG was associated with a lower incidence of pneumonia (4.35% vs. 15.07%, P = 0.047). No mortality was observed in either group. There was no significant difference in the total operative time (284.48 vs. 271.73 min, P = 0.171), but RTG was associated with a lower estimated volume of blood loss (110 vs. 150 ml, P < 0.001) and more total retrieved lymph nodes (LNs) (41.36 vs 35.1, P = 0.019), more extraperigastric LNs (14.91 vs. 12.19, P = 0.024) and more LNs in the suprapancreatic areas (14.68 vs. 11.82, P = 0.017). The laboratory data (amylase, inflammatory, Albumin and T lymphocyte levels) of the RTG group were better than those of the LTG group. CONCLUSION: According to the results of this prospective cohort study, for patients with locally advanced gastric cancer, Robotic surgery has advantages over laparoscopic surgery for radical total gastrectomy with D2 lymphadenectomy performed by well-trained doctors.
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Laparoscopía , Procedimientos Quirúrgicos Robotizados , Neoplasias Gástricas , Gastrectomía/efectos adversos , Gastrectomía/métodos , Humanos , Laparoscopía/efectos adversos , Laparoscopía/métodos , Escisión del Ganglio Linfático/métodos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Estudios Prospectivos , Estudios Retrospectivos , Procedimientos Quirúrgicos Robotizados/efectos adversos , Procedimientos Quirúrgicos Robotizados/métodos , Neoplasias Gástricas/patología , Neoplasias Gástricas/cirugía , Resultado del TratamientoRESUMEN
In this study, ovalbumin (OVA) interacted with pectin (PE) to form soluble electrostatic complexes to improve the functional properties of high internal phase Pickering emulsions (HIPEs) under extreme conditions. The results showed that the stability of the OVA-PE soluble complexes-stabilized HIPEs was significantly better than that of the free OVA-stabilized HIPEs and was modulated by the biopolymer ratio. In particular, the complexes at an OVA:PE ratio of 1:1 (C-1:1) may form particulates with a core-shell structure by a flocculation mechanism. The C-1:1-stabilized HIPEs had the smallest oil droplet size (11.34 ± 1.14 µm) and the best resistance to extreme environmental stresses due to their strong, rigid structure and dense interfacial architecture. The in vitro digestion results showed that the bioaccessibility (from 18.3% ± 0.5% to 38.8% ± 4.8%) of curcumin improved with increasing PE content. Our work is helpful in understanding OVA-PE complexes as stabilizers for HIPEs and their potential applications in food delivery systems.
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Curcumina , Curcumina/química , Emulsiones/química , Ovalbúmina , Tamaño de la Partícula , PectinasRESUMEN
The surface characteristics and emulsifying properties of whey proteins (WP) after complexation with nanoliposomes (NL) were investigated. WP surface hydrophobicity enhanced after complexation with NL, and it indicated the exposure increase of WP hydrophobic groups. WPNL interfacial tension significantly decreased compared with that of WP. The interfacial protein content of WPNL-stabilized emulsions was slightly different from that of WP-stabilized emulsions. WP emulsifying properties were significantly improved after complexation with NL. The mean sizes and polydispersity indexes of WPNL-stabilized emulsion droplets were smaller than those of WP-stabilized emulsion droplets. The absolute zeta-potential values of WPNL-stabilized emulsions were greater than those of WP-stabilized emulsions. Electrostatic repulsion played a vital role in WPNL-stabilized emulsion stability. Moreover, surface and emulsifying properties of WPNL were changed by exterior factor-induced alteration of protein advanced structures. The emulsifying properties of WP after complexation with NL were improved due to the modification of WP surface characteristics.
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Emulsionantes , Emulsionantes/química , Emulsiones/química , Interacciones Hidrofóbicas e Hidrofílicas , Proteína de Suero de Leche/químicaRESUMEN
Egg yolk low density lipoprotein (LDL) was used to prepare high internal phase Pickering emulsions (HIPEs) and its role as a stabilizer was comprehensively studied in this work. LDL exists as homogenous nanoparticles with an average size of 49 nm and amphiphilic nature, having a contact angle close to 90°. HIPEs were studied by varying compositions of 75%-90% oil phase and 25%-10% aqueous phase containing 0.5%-2% LDL. Rheological measurement, confocal laser scanning and optical microscopes imaging together with digital photos revealed the solid gel network, the strength of which was dependent upon oil volume fraction and LDL concentration. Optimal formulation of HIPEs was found as 80% oil and 2% LDL concentration, which exhibited small droplets under 10 µm with negligible aggregations, even after four weeks storage under refrigeration or heating at 90 â for 30 min. After three freeze-thawing cycles, the HIPEs were demulsified losing their gel structure, but a simple re-homogenization was able to reconstitute the gel network identical to original microstructure. Encapsulation of curcumin into Pickering HIPEs provided exceptional photostability (around 80% retention rate) against ultraviolet radiation and improved its bioaccessibility from 10% to 50% during in vitro digestion. Our findings may bring new opportunities to design semi-solid foods using natural and edible ingredients.
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Curcumina , Curcumina/química , Yema de Huevo , Emulsiones/química , Lipoproteínas LDL , Tamaño de la Partícula , Rayos UltravioletaRESUMEN
BACKGROUND: Laparoscopic gastrectomy (LG) has been increasingly used for the treatment of locally advanced Siewert type II and III adenocarcinoma of the esophagogastric junction (AEG). However, whether LG can achieve the same short-term efficacy in the treatment of patients who receive neoadjuvant chemotherapy (NACT) remains controversial. Thus, the aim of this study was to investigate the clinical outcomes of NACT combined with LG for Siewert type II and III AEG. METHODS: This retrospective study identified patients with locally advanced Siewert type II and III AEG diagnosed between May 2011 and October 2020 using the clinical tumor-node-metastasis (cTNM) staging system. The short-term outcomes were compared between the matched groups using a 1:3 propensity score matching (PSM) method, which was performed to reduce bias in patient selection. RESULTS: After PSM, 164 patients were selected, including 41 in the NACT group and 123 in the LG group. The baseline characteristics were similar between the two groups. Compared with the LG group, the NACT group exhibit a smaller tumor size and significantly less advanced pathological tumor classification and nodal classification stages. The time to first flatus of the NACT group was significantly shorter, but the hospital stay was significantly longer than that of the LG group. The NACT group showed similar overall (29.3% vs 25.2%, P=0.683), systemic (24.4% vs 21.1%, P=0.663), local (12.2% vs 9.8%, P=0.767), minor (19.5% vs 19.5%, P=1.000) and major (9.8% vs 5.7%, P=0.470) complications as the LG group. Subgroup analyses showed no significant differences in most stratified parameters. Operation time≥ 300 minutes was identified as an independent risk factor for overall complications. Age≥ 60 years was identified as an independent risk factor for major complications. CONCLUSION: NACT combined with LG for AEG does not increase the risk of postoperative morbidity and mortality compared with LG.
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Phytoglycogen (PG), a water-soluble glycogen-like α-d-glucan, exists as natural dendritic nanoparticles which are known as a promising solubility enhancer and delivery vehicle for lipophilic compounds. However, the practical applications of PG in food and pharmaceutical fields are limited by their high hydrophilicity and relatively low encapsulation efficiency compared with other delivery systems. The objectives of this work were to chemically modify native PG nanoparticles with hydrophobic groups and to characterize their physicochemical properties, as well as to evaluate the application feasibility of modified PG (mPG) nanoparticles as a carrier for hydrophobic bioactive compounds. The surface hydroxyl groups of PG nanoparticles were capped with various anhydrides, e.g., acetic, valeric, and N-caprylic, to obtain the PG nanoparticles with different hydrophobicity. Successful modification by acyl groups was evidenced by both Fourier-transform infrared and nuclear magnetic resonance spectroscopies. The mPG nanoparticles exhibited a more compact structure and homogeneous size distribution as revealed by dynamic light scattering measurement and visualized by transmission electron microscope, while their size slightly increased with the chain length of anhydride. Rheological measurement revealed that the viscosity of mPG at low shear rate was increased with the increase of degree of substitution due to the intermolecular hydrophobic association. A novel pH-driven method to load curcumin showed significantly higher encapsulation efficiency and greater antioxidant activity compared with traditional ethanol mediated loading method. Hydrophobic modification of natural dendritic PG nanostructures demonstrates promising potential to develop food-grade nanocarriers for lipophilic bioactive compounds with improved bioactivity.
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Curcumina , Nanopartículas , Interacciones Hidrofóbicas e Hidrofílicas , Tamaño de la Partícula , Solubilidad , AguaRESUMEN
The interaction mechanism between liposomes (Lips) and whey protein isolates (WPI) with different mass ratios was explored in this paper. After binding with different concentration of Lips, the changes in hydrophilic and hydrophobic regions of WPI were investigated with fluorescein isothiocyanate (FITC) and pyrene fluorescence probes. The spatial structure changes of WPI were further characterized by differential scanning calorimetry, Fourier transform infrared spectroscopy, and circular dichroism. The results indicated that the structure of WPI was changed due to binding with Lips in hydrophilic and hydrophobic groups. The binding process might result in the migration, recombination, and alignment of WPI and Lip groups. Moreover, the oil-water interfacial tension with WPI decreased from 9.20 mN/m to 3.29 mN/m upon increasing the Lip-to-WPI ratio. This work suggests that the physiochemical properties of Lip-WPI complexes could be manipulated by adjusting the Lip-to-WPI ratio. This study shed some light on the mechanism explanation of the WPI structural changes due to the interaction with Lips during food processing.
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Interacciones Hidrofóbicas e Hidrofílicas , Liposomas/metabolismo , Proteína de Suero de Leche/metabolismo , Rastreo Diferencial de Calorimetría , Liposomas/química , Espectroscopía Infrarroja por Transformada de Fourier , Tensión Superficial , Proteína de Suero de Leche/químicaRESUMEN
BACKGROUND: Whether laparoscopic gastrectomy is suitable for patients with serosa-invasive gastric cancer remains controversial. We performed this study to evaluate the short- and long-term outcomes after laparoscopic gastrectomy compared with after open gastrectomy. METHODS: We retrospectively analyzed 906 consecutive patients with serosa-invasive gastric cancer from January 2004 to December 2014 in our center, who underwent laparoscopic gastrectomy or open gastrectomy with D2 lymphadenectomy. After propensity score matching, 334 patients were included in each group. Surgical conditions and short- and long-term results were compared. RESULTS: Laparoscopic gastrectomy was associated with less estimated blood loss and longer operation time, while the number of harvested lymph nodes was not significantly different between laparoscopic gastrectomy and open gastrectomy. Patients who underwent laparoscopic gastrectomy had an earlier time to first flatus, first diet, and first ambulation and were discharged earlier. Overall and pulmonary postoperative complication rates were lower in the laparoscopic gastrectomy group. With a minimum follow-up of 60 months, the 5-year overall survival was 39.3% in the laparoscopic gastrectomy group and 34.3% in the open gastrectomy group, and the 5-year disease-free survival was 36.4% in the laparoscopic gastrectomy group and 32.7% in the open gastrectomy group. Laparoscopic gastrectomy was associated with better 5-year overall survival in patients aged ≥60 years. The overall recurrence rates and patterns were not significantly different between the 2 groups. CONCLUSION: Laparoscopic gastrectomy is an alternative surgical approach for patients with serosa-invasive gastric cancer in terms of short-term outcomes and long-term survival, and it might be more advantageous for certain populations.
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Gastrectomía , Laparoscopía , Neoplasias Gástricas/cirugía , Pérdida de Sangre Quirúrgica/estadística & datos numéricos , Supervivencia sin Enfermedad , Femenino , Gastrectomía/efectos adversos , Gastrectomía/métodos , Gastrectomía/mortalidad , Humanos , Laparoscopía/efectos adversos , Laparoscopía/métodos , Laparoscopía/mortalidad , Escisión del Ganglio Linfático/métodos , Escisión del Ganglio Linfático/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Tempo Operativo , Puntaje de Propensión , Estudios Retrospectivos , Membrana Serosa/patología , Membrana Serosa/cirugía , Neoplasias Gástricas/mortalidad , Neoplasias Gástricas/patología , Análisis de Supervivencia , Resultado del TratamientoRESUMEN
The effects of low-frequency magnetic field combined with different heating rates on pork myofibrillar protein (MP) gels were investigated. Samples were treated under different heating rates (1 °C/min and 2 °C/min) in the presence or absence of 9.5 mT low-frequency magnetic field. The highest levels of intermolecular and intramolecular ionic and hydrogen bonds in MP were observed at the heating rate of 2 °C/min under the 9.5 mT magnetic field. These bonds resulted in decreasing the α-helix and increasing the ß-sheet and ß-turn, which promoted the formation of a more uniform microstructure. It also increased the proportion of bound water, increasing the ability of MP to bind with water. This effect, combined with the weaker hydrophobic interactions, as confirmed by the reduced content of tryptophan and aliphatic residues, explained well the high water-holding capacity of MP induced by heating at 2 °C/min under the 9.5 mT magnetic field.
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Geles/química , Campos Magnéticos , Proteínas Musculares/química , Miofibrillas/química , Carne de Cerdo , Animales , Calefacción , Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Reología , Agua/químicaRESUMEN
Ovalbumin (OVA) is an important protein emulsifier. However, it is unstable near the isoelectric point pH, which limits its applications in the food industry. Polysaccharides may be explored to tackle this challenge by improving its pH-dependent instability. In this work, carboxymethyl cellulose (CMC) was used as a model polysaccharide to mix with OVA near its isoelectric point (pH 4.7) with subsequent mild heating at 60 °C for 30 min. The molecular interactions between OVA and CMC were comprehensively studied via a series of characterizations, including turbidity, zeta potential, intrinsic fluorescence, surface hydrophobicity, circular dichroism (CD) spectra and Fourier transform infrared spectroscopy (FTIR). The droplet sizes of the emulsions prepared by OVA-CMC were measured to analyze emulsifying property and stability. The results indicated that free OVA was easily aggregated due to loss of surface charges, while complexing with CMC significantly inhibited OVA aggregation before and after heating owing to the strong electrostatic repulsion. In addition, OVA exposed more hydrophobic clusters after heating, which resulted in the growth of surface hydrophobicity. Altogether, the heated OVA-CMC complexes presented the best emulsifying property and stability. Our study demonstrated that complexing OVA with CMC not only greatly improved its physicochemical properties but also significantly enhanced its functionality as a food-grade emulsifying agent, expanding its applications in the food industry, as development of emulsion-based acidic food products.
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Carboximetilcelulosa de Sodio/química , Ovalbúmina/química , Dicroismo Circular , Emulsionantes/química , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Punto Isoeléctrico , Concentración Osmolar , Espectroscopía Infrarroja por Transformada de Fourier , Electricidad Estática , TemperaturaRESUMEN
The effects of low frequency magnetic field (0-12 mT) on hydrogen peroxide oxidized myoglobin-isolate (MbI) were investigated. The results indicate that the primary target of the hydrogen peroxide oxidation was Met(FeIII)Mb, leading to the fall off of iron ions from the porphyrin ring. Additionally, the increased magnetic field (≥9 mT) enhanced the release of more iron ions to react with H2O2, giving rise to the production of more hydroxyl radicals and the shift of oxidation site from porphyrin ring to Mb skeleton. Moreover, the directional movement of iron ions induced by magnetic field caused the generation of local micro-electric field and the rearrangement of charged groups on the protein surface or near-surface, thus affecting Mb aggregation. Overall, the magnetic field interfered with the hydrogen peroxide chain reaction process, changed the redox equivalents of Mb, and shifted the oxidation sites of Mb.
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Peróxido de Hidrógeno/química , Mioglobina/química , Compuestos Férricos/química , Radical Hidroxilo/química , Hierro/química , Campos Magnéticos , Oxidación-Reducción , Porfirinas/químicaRESUMEN
In this study, the adsorption/desorption characteristics of rapeseed meal polysaccharides extract on four resins (HP-20, D3520, XAD-16, and AB-8) were evaluated. The results indicated that HP-20 resin had the best purification effect. Based on static adsorption test, the kinetics and isotherms of the four resins for protein and polysaccharide were investigated. The adsorption test showed that the pseudo-second-order kinetics model and the Freundlich isotherm model were more suitable for explanation of the adsorption process for protein and polysaccharide. Static desorption test showed that the highest protein desorption ratios of HP-20, D3520, and AB-8 resins could be obtained with 60% ethanol solution as eluate, and the highest protein desorption ratios of XAD-16 resin could be obtained with 40% ethanol solution as eluate. Dynamic adsorption/desorption tests of HP-20 resin showed that the deproteinization ratio was 91% and the polysaccharide recovery ratio was 62% when the treatment amount was 1.5 BV. Compared with three traditional methods, HP-20 resin adsorption method that the deproteinization ratio was 82% was more potent than the three traditional methods for purifying polysaccharides from rapeseed meal. In addition, UV/vis spectroscopy showed that most of the protein was absorbed by resins, and FT-IR spectroscopy indicated that the purity of the polysaccharide after purification was improved. Rapeseed meal polysaccharides could be effectively deproteinized using HP-20 resin, and it was suitable for purifying polysaccharides from rapeseed meal.