360 research outputs found
On averaging block Kaczmarz methods for solving nonlinear systems of equations
A class of averaging block nonlinear Kaczmarz methods is developed for the
solution of the nonlinear system of equations. The convergence theory of the
proposed method is established under suitable assumptions and the upper bounds
of the convergence rate for the proposed method with both constant stepsize and
adaptive stepsize are derived. Numerical experiments are presented to verify
the efficiency of the proposed method, which outperforms the existing nonlinear
Kaczmarz methods in terms of the number of iteration steps and computational
costs
On multi-step extended maximum residual Kaczmarz method for solving large inconsistent linear systems
A multi-step extended maximum residual Kaczmarz method is presented for the
solution of the large inconsistent linear system of equations by using the
multi-step iterations technique. Theoretical analysis proves the proposed
method is convergent and gives an upper bound on its convergence rate.
Numerical experiments show that the proposed method is effective and
outperforms the existing extended Kaczmarz methods in terms of the number of
iteration steps and the computational costs
Perceive, Excavate and Purify: A Novel Object Mining Framework for Instance Segmentation
Recently, instance segmentation has made great progress with the rapid
development of deep neural networks. However, there still exist two main
challenges including discovering indistinguishable objects and modeling the
relationship between instances. To deal with these difficulties, we propose a
novel object mining framework for instance segmentation. In this framework, we
first introduce the semantics perceiving subnetwork to capture pixels that may
belong to an obvious instance from the bottom up. Then, we propose an object
excavating mechanism to discover indistinguishable objects. In the mechanism,
preliminary perceived semantics are regarded as original instances with
classifications and locations, and then indistinguishable objects around these
original instances are mined, which ensures that hard objects are fully
excavated. Next, an instance purifying strategy is put forward to model the
relationship between instances, which pulls the similar instances close and
pushes away different instances to keep intra-instance similarity and
inter-instance discrimination. In this manner, the same objects are combined as
the one instance and different objects are distinguished as independent
instances. Extensive experiments on the COCO dataset show that the proposed
approach outperforms state-of-the-art methods, which validates the
effectiveness of the proposed object mining framework.Comment: Accepted by CVPR Workshops 202
Motion-state Alignment for Video Semantic Segmentation
In recent years, video semantic segmentation has made great progress with
advanced deep neural networks. However, there still exist two main challenges
\ie, information inconsistency and computation cost. To deal with the two
difficulties, we propose a novel motion-state alignment framework for video
semantic segmentation to keep both motion and state consistency. In the
framework, we first construct a motion alignment branch armed with an efficient
decoupled transformer to capture dynamic semantics, guaranteeing region-level
temporal consistency. Then, a state alignment branch composed of a stage
transformer is designed to enrich feature spaces for the current frame to
extract static semantics and achieve pixel-level state consistency. Next, by a
semantic assignment mechanism, the region descriptor of each semantic category
is gained from dynamic semantics and linked with pixel descriptors from static
semantics. Benefiting from the alignment of these two kinds of effective
information, the proposed method picks up dynamic and static semantics in a
targeted way, so that video semantic regions are consistently segmented to
obtain precise locations with low computational complexity. Extensive
experiments on Cityscapes and CamVid datasets show that the proposed approach
outperforms state-of-the-art methods and validates the effectiveness of the
motion-state alignment framework.Comment: Accepted by CVPR Workshops 202
Kaempferol Induces G2/M Cell Cycle Arrest via Checkpoint Kinase 2 and Promotes Apoptosis via Death Receptors in Human Ovarian Carcinoma A2780/CP70 Cells
Kaempferol is a widely distributed dietary flavonoid. Epidemiological studies have demonstrated kaempferol consumption lowers the risk of ovarian cancer. Our previous research proved that kaempferol suppresses human ovarian cancer cells by inhibiting tumor angiogenesis. However, the effects of kaempferol on the cell cycle and extrinsic apoptosis of ovarian cancer cells have not yet been studied. In the present study, we demonstrated that kaempferol induced G2/M cell cycle arrest via the Chk2/Cdc25C/Cdc2 pathway and Chk2/p21/Cdc2 pathway in human ovarian cancer A2780/CP70 cells. Chk2 was not responsible for kaempferol-induced apoptosis and up-regulation of p53. Kaempferol stimulated extrinsic apoptosis via death receptors/FADD/Caspase-8 pathway. Our study suggested that Chk2 and death receptors played important roles in the anticancer activity of kaempferol in A2780/CP70 cells. These findings provide more evidence of the anti-ovarian cancer properties of kaempferol and suggest that kaempferol could be a potential candidate for ovarian cancer adjuvant therapy
Microneedle interventional therapy combined with cervical spine manipulation for cervicogenic dizziness
Formiranje produkata Maillardove reakcije u odležanom octu od sirka i zaštitni učinak melanoidina iz octa na jetru štakora oštećenu tetraklormetanom
Research background. The processing method generally affects the toxicity and biological activity of aged sorghum vinegar. This study investigates the changes in the intermediate Maillard reaction products of sorghum vinegar during ageing and the in vivo hepatoprotective effects of pure melanoidin obtained from it.
Experimental approach. High-performance liquid chromatography (HPLC) and fluorescence spectrophotometry were utilized to quantify intermediate Maillard reaction products. The CCl4-induced liver damage in rats was used to evaluate the protective role of pure melanoidin in rat liver.
Results and conclusions. Compared with the initial concentration, the 18-month ageing process caused a 1.2- to 3.3-fold increase in the concentrations of intermediate Maillard reaction products, i.e. 5-hydroxymethylfurfural (HMF), 5-methylfurfural (MF), methyglyoxal (MGO), glyoxal (GO) and advanced glycation end products (AGEs). The concentrations of HMF in the aged sorghum vinegar were 6.1-fold higher than the 450 μM limit standard for honey, implying the need for shortening the ageing of the vinegar in practice for safety concerns. Pure melanoidin (Mr>3.5 kDa) demonstrated significant protective effects against CCl4-induced rat liver damage, as evidenced by normalized serum biochemical parameters (transaminases and total bilirubin), suppressing hepatic lipid peroxidation and reactive oxygen species, as well as increasing glutathione amount and restoring antioxidant enzyme activities. Histopathological analysis revealed that melanoidin in vinegar reduced cell infiltration and vacuolar hepatocyte necrosis in rat liver. The findings demonstrated that a shortened ageing process should be considered in practice to ensure the safety of aged sorghum vinegar. Vinegar melanoidin is a potential alternative for the prevention of hepatic oxidative damage.
Novelty and scientific contribution. This study demonstrates that the manufacturing process had a profound influence on the generation of vinegar intermediate Maillard reaction products. In particular, it revealed the in vivo hepatoprotective effect of pure melanoidin from aged sorghum vinegar, and provides insight into the in vivo biological activity of melanoidin.Pozadina istraživanja. Postupak pripreme često utječe na toksičnost i biološku aktivnost odležanog octa od sirka. U ovom su radu ispitane promjene u međuproduktima Maillardove reakcije u octu od sirka tijekom starenja, te in vivo hepatoprotektivni učinak čistog melanoidina izdvojenog iz dobivenog octa.
Eksperimentalni pristup. Međuprodukti Maillardove reakcije određeni su visokodjelotvornom tekućinskom kromatografijom i fluorescencijskom spektrofotometrijom. Hepatoprotektivno djelovanje čistog melanoidina ispitano je na jetri šakora oštećenoj tetraklormetanom.
Rezultati i zaključci. U usporedbi s početnom koncentracijom, koncentracija međuprodukata Maillardove reakcije u octu odležanom tijekom 18 mjeseci, i to 5-hidroksimetilfurfurala (HMF), 5-metilfurfurala (MF), metilglioksala (MGO), glioksala (GO) i konačnih produkata glikacije (engl. AGEs), porasla je za 1,2 do 3,3 puta. Koncentracija HMF-a u odležanom octu od sirka bila je 6,1 puta veća od dozvoljene granice od 450 μM u medu kao standardu, što znači da je u praksi potrebno skratiti vrijeme odležavanja octa radi postizanja sigurnosti njegove uporabe za potrošače. Čisti melanoidin (Mr>3,5 kDa) je učinkovito štitio jetru štakora od oštećenja izazvanih tetraklormetanom, što su potvrdili normalizirani biokemijski parametri seruma (aktivnost transaminaze i koncentracija ukupnih bilirubina), smanjena lipidna peroksidacija u jetri i manja količina reaktivnih spojeva kisika, te veća količina glutationa uz obnovljenu aktivnost enzima. Histopatološka analiza je pokazala da je melanoidin u octu smanjio staničnu infiltraciju i nekrozu hepatocita u jetri štakora. Rezultati pokazuju da bi u praksi trebalo razmotriti skraćeno vrijeme odležavanja octa od sirka, da bi on bio siguran za primjenu. Melanoidin iz octa može se koristiti umjesto lijekova za zaštitu jetre od oksidacijskog oštećenja.
Novina i znanstveni doprinos. U radu je prikazano da postupak proizvodnje bitno utječe na stvaranje međuprodukata Maillardove reakcije u octu. Poglavito je prikazan in vivo hepatoprotektivni učinak čistog melanoidina iz odležanog octa od sirka, te je dan uvid u in vivo biološku aktivnost melanoidina
Effects of Temperature on the Quality of Vacuum Concentrated Pear Juice and Construction of Quality Evaluation Model
Objective: To compare the quality of vacuum concentrated pear juice at different temperatures and construct a quality evaluation method for concentrated pear juice. Method: Fresh pear juice was concentrated under decompression condition (vacuum degree 0.005 MPa) at concentration temperatures of 50, 60, 70 and 80 ℃, respectively. The evaluation model of concentrated pear juice was constructed based on the browning degree, pH, total phenolic content, total flavonoid content, Fe3+reducing power, soluble sugar, organic acid and volatile components of the concentrated pear juice. Results: The content of tartaric acid, fumaric acid and pH decreased significantly with the increasing temperature, while the browning degree, total phenolic content, total flavonoid content, Fe3+reducing power, quinic acid, malic acid, citric acid increased significantly. The content of alcohols was the highest in concentrated pear juice of 50 ℃ (4.753 μg/mL), the esters was the highest in concentrated pear juice of 70 ℃ (2.808 μg/mL), the aldehydes and ketones were the highest in concentrated pear juice of 70 ℃ (12.478 μg/mL). This study obtained a model for evaluating the quality of concentrated pear juice and found that 70 ℃ was best vacuum concentration temperature for pear juice. Conclusion: The vacuum concentration temperature could affect the quality of concentrated pear juice, which could be well distinguished by the quality evaluation model. This study would provide references for the quality control of vacuum concentrated pear juice
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