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1.
Int J Biol Macromol ; 268(Pt 2): 131788, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38657931

RESUMO

While individual starch types may not possess the ideal gelatinization and retrogradation properties for specific applications, the amalgamation of multiple starch varieties might bestow desirable physicochemical properties upon resulting starch-based products. This study explored the impact of incorporating purple rice starch (PRS), as a novel starch variant (up to 15 % PRS), on the gelatinization and retrogradation (within 14 days) of regular wheat starch (WS). Rheological and texture assessments demonstrated that the introduction of PRS diminished the viscoelasticity and hardness of fresh WS paste. Additionally, in the case of retrograded WS pastes stored at 4 °C for 1-14 days, the incorporation of 10 % or 15 % PRS effectively retarded the reduction in transparency and significantly reduced hardness, retrogradation degree, the ratio of absorbance at 1047/1017 cm-1, and relative crystallinity. Notably, 10 % PRS results in a more pronounced effect. Conversely, 5 % PRS induced an opposing impact on retrograded WS post-storage. Moreover, scanning electron microscopy revealed that as the proportion of PRS increased, the microstructure of gelatinized WS-PRS closely resembled that of pure PRS. In conclusion, the diverse effects of varying PRS proportions on WS alter the texture and characteristics of starch-based foods, underscoring the potential of starch blending for improved applications.


Assuntos
Oryza , Reologia , Amido , Triticum , Amido/química , Triticum/química , Oryza/química , Viscosidade , Dureza
2.
Chem Commun (Camb) ; 60(17): 2385-2388, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38321968

RESUMO

We present a red light-activated zincII bis(dipyrrin) symmetry breaking charge transfer (SBCT) architecture, showing a large molar absorption coefficient (ε = 15.4 × 104 M-1 cm-1), high reactive singlet oxygen generation efficiency (ΦΔ ≈ 0.8) and long-lived triplet state (τT = 150 µs) compared to the donor-acceptor analogue dipyrrin-BF2 complex, highlighting the superiority of the SBCT approach. For the first time, we demonstrated the potential of a SBCT scaffold in red-light-induced methyl methacrylate (MMA) polymerization, using a dual photocatalyst excitation approach.

3.
Int J Biol Macromol ; 261(Pt 2): 129748, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38281537

RESUMO

The advantages of physically modifying starch are evident: minimal environmental impact, no by-products, and straightforward control. The impact of dual modification on starch properties is contingent upon modification conditions and starch type. Herein, we subjected purple rice starch (PRS) to heat-moisture treatment (HMT, 110 °C, 4 h) with varying moisture content, ultrasound treatment (UT, 50 Hz, 30 min) with different ultrasonic power, and a combination of HMT and UT. Our findings reveal that UT following HMT dispersed starch granules initially aggregated by HMT and resulted in a rougher granule surface. Rheological analysis showcased a synergistic effect of HMT and UT, enhancing the fluidity of PRS and reinforcing its resistance to deformation in paste form. The absorbance ratio R1047/1015 indicates that increased moisture content during HMT and high ultrasound power for UT reduced the short-range order degree (1.69). However, the combined HMT-UT exhibited an increased R1047/1015 (1.38-1.64) compared to HMT alone (1.29-1.45), likely due to short-chain rearrangement. Notably, the A-type structure of PRS remained unaltered, but overall crystallinity significantly decreased (23.01 %-28.56 %), consistent with DSC results. In summary, physical modifications exerted significant effects on PRS, shedding light on the mechanisms governing the transformation of structural properties during HMT-UT.


Assuntos
Temperatura Alta , Oryza , Oryza/química , Amido/química , Fenômenos Químicos
4.
Int J Biol Macromol ; 254(Pt 3): 127885, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37926307

RESUMO

To comprehend the intricate interplay of five common food polysaccharides, κ-Carrageenan (KC), konjac glucomannan (KGM), locust bean gum (LBG), low-acyl gellan gum (LAG), and sodium alginate (SA), within composite polysaccharide gels, widely employed for textural modulation and flavor enhancement. This study systematically modulates the quantities of these five polysaccharides to yield six distinct multi-polysaccharide gels. The unique impact of each polysaccharide on the overall quality of composite gels were studied by thermostability, microstructure, water-holding capacity (WHC), texture, and sensory attributes. The findings unequivocally manifest the phenomenon of thermoreversible gelation in all composite gels, except for the KC-devoid sample, which displayed an inability to solidify. Notably, KGM, LBG, and LAG emerged as pivotal enhancers of the network structure in these composite gels, while SA was identified as a promotor of layered structure, resulting in a reduction of surface hardness. Leveraging principal component analysis (PCA) to analyzed 14 critical evaluation parameters of the five multi-polysaccharide gels, revealing the order as follows: KC > KGM > SA > LAG > LBG. These findings would imparts valuable insights into the pragmatic utilization of multi-polysaccharide gels for the development of food products (e.g. Bobo balls in milk tea) with tailored textural and sensory attributes.


Assuntos
Alginatos , Mananas , Carragenina/química , Mananas/química , Polissacarídeos Bacterianos/química , Géis/química
5.
Chemistry ; 29(1): e202202677, 2023 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-36250277

RESUMO

Tuning the redox potential of commonly available photocatalyst to improve the catalytic performance or expand its scope for challenging synthetic conversions is an ongoing demand in synthetic chemistry. Herein, the excited state properties and redox potential of commercially available [Ru(bpy)3 ]2+ photocatalyst were tuned by modifying the structure of the bipyridine ligands with electron-donating/withdrawing units. The visible-light-mediated photoredox phosphorylation of tertiary aliphatic amines was demonstrated under mild conditions. A series of cross-dehydrogenative coupling reactions were performed employing the RuII complexes as photocatalyst giving the corresponding α-aminophosphinoxides and α-aminophosphonates via carbon-phosphorus (C-P) bond formation.

6.
Phys Chem Chem Phys ; 24(35): 20901-20912, 2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36047252

RESUMO

Herein, a series of compact anthracene carboxyimide (ACI) based donor-acceptor dyads were prepared by substituting bulky aryl moieties with various electron-donating ability to study the triplet-excited state properties. The ISC mechanism and triplet yield of the dyads were successfully tuned via structural manipulation. Efficient ISC (ΦΔ ≈ 99%) and long-lived triplet state (τT ≈ 122 µs) was observed for the orthogonal anthracene-labeled ACI derivative compared to the Ph-ACI and NP-ACI dyads, which showed fast triplet state decay (τT ≈ 7.7 µs). Femtosecond transient absorption study demonstrated the ultrafast charge separation (CS) and efficient charge recombination (CR) in the orthogonal dyads and ISC occurring via spin-orbit charge transfer (SOCT) mechanism (AN-ACI: τCS = 355 fs, τCR = 2.41 ns; PY-ACI: τCS = 321 fs, τCR = 1.61 ns), while in Ph-ACI and NP-ACI dyads triplet populate following the normal ISC channel (nπ* → ππ* transition), no CS was observed. We found that the attachment of suitable aryl donor moiety (AN- or PY-) to the ACI core can ensure the insertion of the intermediate triplet state, resulting in a small energy gap among charge separated state (CSS) and triplet state, which leads to efficient ISC in these derivatives. The SOCT-ISC-based AN-ACI dyad was confirmed to be a potent photodynamic therapeutic reagent; an ultra-low IC50 value (0.27 nM) that was nearly 214 times lower than that of the commercial Rose Bengal photosensitizer (57.8 nM) was observed.


Assuntos
Elétrons , Fármacos Fotossensibilizantes , Antracenos , Indicadores e Reagentes , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia
7.
Zhonghua Gan Zang Bing Za Zhi ; 13(4): 249-51, 2005 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-15850508

RESUMO

OBJECTIVE: To study the practical use of the model for end-stage liver disease (MELD) in clinics and to assess its validity in predicting the prognoses of patients with severe viral hepatitis and to determine the validity of the model by the concordance (c)-statistic which is equivalent to the area under the receiver operating characteristic (ROC) curve. Also, the optimal cutoff values of MELD to discriminate between deceased and surviving patients were calculated using ROC curves. METHODS: 121 patients were divided into a plasma exchange (PE) group and a non-plasma exchange (non-PE) group, and they were graded with the MELD formula. The death rate was observed within three months. RESULTS: 81 patients died within 3 months (35 cases in the PE group, 46 cases in the non-PE group). The mortality rates of patients in the PE group whose MELD scores were between 20 to 30 and 30 to 40 were 31.6% and 57.7% respectively, but in non-PE cases they were 67.6%, 81.3% respectively; there was a significant difference between the PE group and non-PE group. The mortality rates of patients whose MELD score was higher than 40 were 93.3% in the PE group and 100% in the non-PE group, however there was no significant difference between the two groups. The optimal cut-off values of MELD to predict the prognoses of patients were 30 in the PE group whose sensitivity, specificity and c-statistic were 80.0%, 52.0% and 0.777, but in the non-PE group they were 25, 82.6%, 86.7% and 0.869, respectively. CONCLUSIONS: This study suggests that MELD scores can serve as an index of the severity of the disease of patients with severe viral hepatitis, and that the mortality rates of the patients increase with the increase of their MELD scores. MELD can accurately predict the short-term prognoses of patients with severe viral hepatitis.


Assuntos
Hepatite Viral Humana/diagnóstico , Hepatite Viral Humana/mortalidade , Falência Hepática/diagnóstico , Índice de Gravidade de Doença , Progressão da Doença , Hepatite Viral Humana/terapia , Humanos , Falência Hepática/etiologia , Falência Hepática/mortalidade , Modelos Biológicos , Troca Plasmática , Valor Preditivo dos Testes , Prognóstico
8.
World J Gastroenterol ; 11(6): 899-902, 2005 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-15682490

RESUMO

AIM: To study the practical use of the model for end-stage liver disease (MELD) on clinic and assess its validity by the concordance (C)-statistic in predicting the prognosis of the patient with severe viral hepatitis. METHODS: One hundred and twenty-one patients were divided into plasma exchange group and non-plasma exchange group, and were graded with MELD formula. The death rate was observed within 3 mo. RESULTS: Eighty-one patients died within 3 mo (35 cases in PE group, 46 cases in non-PE group). The mortality of patients in PE group whose MELD score between 20-30 and 30-40 were 31.6% and 57.7%, respectively, but in non-PE cases they were 67.6%, 81.3% respectively. There was significant difference between PE group and non-PE group (P<0.05). However, the mortality of patients whose MELD score higher than 40 were 93.3% in PE group and 100% in non-PE group and there was no significant difference between the two groups (P = 0.65>0.05). The optimal cut-off values of MELD to predict the prognosis of patients were 30 in PE group whose sensitivity, specificity and C-statistic were 80.0%, 52.0% and 0.777, but in non-PE group they were 25, 82.6%, 86.7% and 0.869, respectively. CONCLUSION: The MELD score can act as a disease severity index for patients with severe viral hepatitis, and the mortality of the patient increases with the increase of the MELD score. The MELD can accurately predict the short-term prognosis of patients with severe viral hepatitis.


Assuntos
Hepatite Viral Humana/diagnóstico , Hepatite Viral Humana/mortalidade , Índice de Gravidade de Doença , Adolescente , Adulto , Idoso , Feminino , Hepatite Viral Humana/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Troca Plasmática , Valor Preditivo dos Testes , Prognóstico , Sensibilidade e Especificidade
9.
World J Gastroenterol ; 9(1): 152-4, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12508372

RESUMO

AIM: To study the effects of pentoxifylline (PTX) on the content of hepatic TGF-beta1, type I and type III collagen in schistosomiasis japonica mice with liver fibrosis and its mechanism of anti-fibrosis. METHODS: Forty mice with schistosomiasis were divided into four groups: one group as control without any treatment, other three were treated with Praziquantel 500 mg/(kg x d)for 2 d, high dose PTX 360 mg/(kg x d) for 8 wk, and low dose PTX 180 mg/(kg x d) for 8 wk respectively. Immunohistochemical technique and multimedia color pathographic analysis system were applied to observe the content change of hepatic TGF-beta1, type I and type III collagen in schistosomiasis japonica mice with liver fibrosis before and after PTX treatment. RESULTS: Effects of PTX on the content change of hepatic TGF-beta1, type I and type III collagen in schistosomiasis japonica mice with liver fibrosis were related to the dosage of PTX, high dose PTX treated group could significantly reduce the content of TGF-beta1 (0.709+/-0.111), type I (0.644+/-0.108) and type III (0.654+/-0.152) collagen compared with those of control group (0.883+/-0.140, 0.771+/-0.156, 0.822+/-0.129) with statistical significance (P<0.05). Low dose PTX could also reduce the hepatic content of TGF-beta1 (0.752+/-0.152), type I (0.733+/-0.117) and type III (0.788+/-0.147) collagen, but without statistical significance (P>0.05). Both high dose and low dose PTX groups have significant differences on the content of TGF-beta1, type I and type III collagen (P<0.05, P<0.05, P<0.01, respectively). CONCLUSION: High dose of PTX treatment could reduce the content of hepatic TGF-beta1, type I and type III collagen significantly in schistosomiasis japonica mice with liver fibrosis, and thus plays its role of antifibrosis.


Assuntos
Colágeno Tipo III/metabolismo , Colágeno Tipo I/metabolismo , Fígado/efeitos dos fármacos , Fígado/patologia , Pentoxifilina/farmacologia , Esquistossomose Japônica/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Animais , Anti-Helmínticos/farmacologia , Feminino , Fígado/metabolismo , Cirrose Hepática/metabolismo , Cirrose Hepática/parasitologia , Cirrose Hepática/patologia , Camundongos , Praziquantel/farmacologia , Distribuição Aleatória , Esquistossomose Japônica/complicações , Esquistossomose Japônica/patologia , Fator de Crescimento Transformador beta1
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