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1.
J Cell Mol Med ; 26(14): 3837-3849, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35672925

RESUMEN

The PBRM1 (PB1) gene which encodes the specific subunit BAF180 of the PBAF SWI/SNF complex, is highly mutated (~ 40%) in clear cell renal cell carcinoma (ccRCC). However, its functions and impact on cell signalling are still not fully understood. Aerobic glycolysis, also known as the 'Warburg Effect', is a hallmark of cancer, whether PB1 is involved in this metabolic shift in clear cell renal cell carcinoma remains unclear. Here, with established stable knockdown PB1 cell lines, we performed functional assays to access the effects on 786-O and SN12C cells. Based on the RNA-seq data, we selected some genes encoding key glycolytic enzymes, including PFKP, ENO1, PKM and LDHA, and examined the expression levels. The AKT-mTOR signalling pathway activity and expression of HIF1α were also analysed. Our data demonstrate that PB1 deficiency promotes the proliferation, migration, Xenograft growth of 786-O and SN12C cells. Notably, knockdown of PB1 activates AKT-mTOR signalling and increases the expression of key glycolytic enzymes at both mRNA and protein levels. Furthermore, we provide evidence that deficient PB1 and hypoxic conditions exert a synergistic effect on HIF 1α expression and lactate production. Thus, our study provides novel insights into the roles of tumour suppressor PB1 and suggests that the AKT-mTOR signalling pathway, as well as glycolysis, is a potential drug target for ccRCC patients with deficient PB1.


Asunto(s)
Carcinoma de Células Renales , Proteínas de Unión al ADN , Neoplasias Renales , Factores de Transcripción , Animales , Carcinoma de Células Renales/patología , Línea Celular Tumoral , Proliferación Celular/genética , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Glucólisis/genética , Humanos , Neoplasias Renales/patología , Dependencia del Oncogén , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Serina-Treonina Quinasas TOR/genética , Serina-Treonina Quinasas TOR/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
2.
Opt Express ; 30(12): 21698-21709, 2022 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-36224883

RESUMEN

Based on a single-beam injection distributed feedback semiconductor laser (DFB-SL) combining with optical heterodyne, a photonic scheme for generating dual-linear chirp microwave (dual-LCM) signal with identical or complementary chirp is proposed and experimentally demonstrated. For such a scheme, a continuous-wave (CW) light with a frequency of finj is split into two parts. One part is passing through a Mach-Zehnder modulator (MZM) driven by a modified sawtooth signal, and then its intensity varies with time as a sawtooth wave. Such a light is injected to a DFB-SL for generating a single linearly chirped microwave (single-LCM) signal. The other part of the CW light with frequency of finj is sent to a phase modulator (PM) driven by a sinusoidal signal, and one of higher-order sidebands is selected by a tunable optical filter and taken as the referenced light. Through heterodyning the referenced light with the single-LCM signal, a dual-LCM signal with identical (or complementary) chirp can be obtained. The experimental results demonstrate that, by adjusting the injection parameters and the frequency of the sinusoidal signal loaded on the PM, the central frequency of the generated dual-LCM signal can be widely tuned. For the period of the sawtooth signal at 10 µs, the bandwidth for each frequency band included in the generated dual-LCM signal is 19.36 GHz under identical chirp and 16.98 GHz under complementary chirp, respectively. Correspondingly, the time bandwidth product (TBWP) for each frequency band can reach 1.936 × 105 under identical chirp and 1.698 × 105 under complementary chirp, respectively.

3.
Opt Express ; 29(16): 26265-26274, 2021 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-34614936

RESUMEN

Frequency-modulated continuous-wave (FMCW) can be acquired by using a distributed feedback semiconductor laser (DFB-SL) operating at period-one (P1) oscillation under an optical injection modulated by a Mach-Zehnder modulator (MZM). In this work, through introducing another MZM to establish cascade-modulated optical injection, an improved photonic scheme for generating high-quality FMCW is proposed and experimentally demonstrated. The experimental results indicate that, under appropriate injection parameters, the central frequency of the generated FMCW is widely tunable, and the bandwidth is larger than that obtained under a single MZM modulation. Further introducing optical feedback for suppressing the phase noise, the frequency comb contrast of the generated FMCW can be improved obviously.

4.
Appl Opt ; 59(9): 2935-2941, 2020 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-32225845

RESUMEN

Based on a three-level model for quantum dot (QD) lasers, the characteristics of the photonic microwave generated by a QD laser simultaneously subject to optical injection and optical feedback are numerically investigated. First, the performance of the microwave signal generated by an optical injected QD laser operating at period one state are analyzed, and the mappings of the frequency and intensity of the generated microwave in the parameter space of the frequency detuning and injection strength are given, which are roughly similar to those reported experimentally. Next, an optical feedback loop is further introduced to the optically injected QD laser for compressing the linewidth of the microwave signal, and the results demonstrate that the linewidth of the generated microwave can be reduced by at least 1 order of magnitude under suitable feedback parameters. Finally, the effect of the linewidth enhancement factor on the generated microwave signal is analyzed.

5.
Opt Express ; 27(14): 19931-19939, 2019 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-31503747

RESUMEN

Via Santa Fe time series prediction and nonlinear channel equalization tasks, the performances of a reservoir computing (RC) system based on an optical feedback semiconductor laser (SL) under electrical information injection are numerically investigated. The simulated results show that the feedback delay time and strength seriously affect the performances of this RC system. By adopting a current-related optimized feedback delay time and strength, the RC can achieve a good performance for an SL biased within a wide region of 1.1-3.5 times its threshold. The prediction errors are smaller than 0.01 when implementing the Santa Fe tests, and the symbol error rates (SERs) are very low on the order of 10-5 for accomplishing nonlinear channel equalization tests under a signal-to-noise ratio (SNR) of 32 dB. Moreover, under a given RC performance level, the information processing rate of the RC can be improved by increasing the SL current.

6.
Matern Child Nutr ; 14(2): e12540, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-28994511

RESUMEN

This study examined how food-related behaviours differed in mothers and their preschool children by levels of family functioning (cohesion and conflict) and household disorganization (chaos). A nationally representative sample of mothers of preschoolers completed an online survey assessing food-related behaviours of themselves and their children. Maternal and child diet, eating behaviours, and health status; household availability of fruits/vegetables, salty/fatty snacks, and sugar-sweetened beverages; family mealtime atmosphere; and family conflict, cohesion, and household chaos were assessed with valid, reliable scales. Cluster analyses assigned families into low, middle, and high conflict, cohesion, and chaos groups. Participants (n = 550) were 72% White, and 82% had some post-secondary education. Regression analysis examining the association of cluster grouping levels on diet-related behaviour measures revealed that positive home environments (i.e., low family conflict, high family cohesion, and low household chaos) were associated with healthier food-related behaviours (e.g., increased fruits/vegetables intake), whereas negative home environments (i.e., high family conflict, low family cohesion, and high household chaos) were associated with unhealthy food-related behaviours (e.g., greater % total calories from fat) even after controlling for sociodemographic and related behavioural factors. Findings suggest family functioning and household chaos are associated with food-related behaviours. This frequently overlooked component of family interaction may affect intervention outcomes and objectives of educational and interventional initiatives.


Asunto(s)
Fenómenos Fisiológicos Nutricionales Infantiles , Dieta/métodos , Dieta/psicología , Relaciones Familiares/psicología , Conducta Alimentaria/psicología , Fenómenos Fisiologicos Nutricionales Maternos , Adolescente , Adulto , Preescolar , Análisis por Conglomerados , Conflicto Familiar/psicología , Femenino , Estado de Salud , Humanos , Masculino , Persona de Mediana Edad , Madres/psicología , Adulto Joven
7.
J Pediatr Nurs ; 29(6): 536-46, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25135882

RESUMEN

The purpose of this study was to examine the discrepancies between perceived and reported overweight status among U.S. adolescents (n>70,000), and to identify factors contributing to such discrepancies. We used the YRBSS data (years 2001-2009) and found statistically significant, gender and race specific discrepancies between perceived and reported overweight status. Factors such as BMI, school performance, and being sexually active are additional predictors of overweight misperception. The findings suggest that evidence based strategies should be employed to help adolescents establish correct weight perception. These strategies should also be tailored based on gender, race, and weight perception of target audience.


Asunto(s)
Imagen Corporal , Sobrepeso/psicología , Adolescente , Índice de Masa Corporal , Escolaridad , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Factores de Riesgo , Estados Unidos
8.
Neurosci Bull ; 40(2): 241-254, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37755677

RESUMEN

The accumulation and spread of prion-like proteins is a key feature of neurodegenerative diseases (NDs) such as Alzheimer's disease, Parkinson's disease, or Amyotrophic Lateral Sclerosis. In a process known as 'seeding', prion-like proteins such as amyloid beta, microtubule-associated protein tau, α-synuclein, silence superoxide dismutase 1, or transactive response DNA-binding protein 43 kDa, propagate their misfolded conformations by transforming their respective soluble monomers into fibrils. Cellular and molecular evidence of prion-like propagation in NDs, the clinical relevance of their 'seeding' capacities, and their levels of contribution towards disease progression have been intensively studied over recent years. This review unpacks the cyclic prion-like propagation in cells including factors of aggregate internalization, endo-lysosomal leaking, aggregate degradation, and secretion. Debates on the importance of the role of prion-like protein aggregates in NDs, whether causal or consequent, are also discussed. Applications lead to a greater understanding of ND pathogenesis and increased potential for therapeutic strategies.


Asunto(s)
Enfermedad de Alzheimer , Enfermedades Neurodegenerativas , Enfermedad de Parkinson , Priones , Humanos , Enfermedades Neurodegenerativas/patología , Péptidos beta-Amiloides , alfa-Sinucleína , Proteínas tau
9.
Foods ; 13(17)2024 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-39272448

RESUMEN

The Dietary Guidelines for Americans (DGA) recommend twice-weekly consumption of seafood for health benefits, yet many U.S. consumers have historically fallen short of this target. The economic and societal impacts of the COVID-19 pandemic brought concern about further declines in seafood intake. This study evaluated the influence of COVID-19 on seafood intake among U.S. residents, toward understanding potential public health implications. A nationally representative cross-sectional survey of 1200 U.S. residents conducted in June 2021 evaluated the frequency and types of seafood consumed, and purchase methods used, before and during the early stages of the COVID-19 pandemic. The results (weighted data) indicate most U.S. consumers (90%) eat seafood, yet only 19% meet the seafood DGA. The likelihood of meeting the DGA was higher among consumers who were Asian, Black, or Hispanic; older; unmarried; of higher income; familiar with the DGA; choosing seafood for health reasons; and living in Atlantic or Gulf coast states. During COVID-19, some increased seafood intake for health reasons (45%), while others reduced intake due to factors such as cost (29%), limited availability (16%), and challenges with preparation (11%). Fresh salmon (68%), frozen shrimp (59%), and cooked oysters (41%) were most frequently purchased by consumers of these foods. More consumers indicated purchasing wild salmon (62%), shrimp (44%), and oysters (51%) than farm-raised products, though many were unsure. Fewer consumers included seafood in online grocery orders (36%) than meal kit orders (61%) when using these services. Though many consumers continued to eat seafood despite decreased restaurant patronage, most did not reach the intake level needed to maximize health benefits. Educational and marketing efforts promoting the health benefits of seafood and the convenience of procurement via online purchase methods may encourage intake across demographic groups to benefit public health outcomes in the U.S.

10.
J Glob Antimicrob Resist ; 38: 223-226, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38723713

RESUMEN

OBJECTIVES: The aim of this study was to characterize an NDM-1-producing Acinetobacter seifertii isolates from a patient in South Korea. METHODS: Antibiotic susceptibility testing and genotyping using multigene sequencing were performed and whole plasmid sequences were determined. RESULTS: The genotype of A. seifertii was ST1899 and was resistant to ceftazidime, trimethoprim-sulfamethoxazole, and piperacillin-tazobactam, in addition to carbapenem. blaNDM-1 was surrounded by the ISAba125 insertion sequence within the structure of Tn125 in the 47 kb-sized plasmid. The plasmid exhibited a structure similar to that of other plasmids of diverse Acinetobacter sp. found worldwide. Transconjugation and the growth curve indicated that the plasmid was adapted to A. seifertii rather than other closely related Acinetobacter sp. CONCLUSIONS: Acquisition of carbapenem resistance by horizontal transfer of the blaNDM-1-carrying plasmid from another Acinetobacter species was found with no growth defect.


Asunto(s)
Infecciones por Acinetobacter , Acinetobacter , Antibacterianos , Pruebas de Sensibilidad Microbiana , Plásmidos , beta-Lactamasas , Acinetobacter/genética , Acinetobacter/efectos de los fármacos , Acinetobacter/aislamiento & purificación , Acinetobacter/enzimología , beta-Lactamasas/genética , Plásmidos/genética , Humanos , República de Corea , Antibacterianos/farmacología , Infecciones por Acinetobacter/microbiología , Farmacorresistencia Bacteriana Múltiple/genética , Transferencia de Gen Horizontal , Genotipo , Carbapenémicos/farmacología , Conjugación Genética
11.
Front Med (Lausanne) ; 11: 1350975, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39050544

RESUMEN

Objective: To explore the application effect of the online and offline mixed teaching mode in nursing practice teaching based on the Source Message Channel Receiver (SMCR) communication model. Methods: By using the convenience sampling method, 15 nursing students who practiced their internship in the Department of Critical Care Medicine at Beijing Friendship Hospital affiliated to Capital Medical University for 4 weeks, from 1 April 2022 to 31 December 2023, were selected as the experimental group. A total of 16 nursing students who practiced in the same hospital in 2021 were selected as the control group. The control group used traditional teaching mode for teaching, and the experimental group used the online and offline teaching mode for teaching. The theoretical and practical achievements, competency, and teaching satisfaction of the two groups of nursing students were compared and analyzed after the internship. Results: The theoretical knowledge, operational performance, competence of the nurses, and satisfaction with the teaching in the experimental group were higher than those of the control group (P < 0.05). Conclusion: Based on the SMCR communication model, exploring the online and offline mixed teaching mode plays an important role in the teaching process of nursing practice, which can not only effectively improve the comprehensive performance of nursing students but also help to improve their satisfaction with teaching and has a positive impact on the cultivation of high-quality nursing talents.

12.
Int Immunopharmacol ; 134: 112143, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38692016

RESUMEN

Chronic inflammation is a significant contributor to hypertensive heart failure. Carnosol (Car), primarily derived from the sage plant (Salvia carnosa), exhibits anti-inflammatory properties in a range of systems. Nevertheless, the influence of angiotensin II (Ang II) on cardiac remodeling remains uncharted. Car was shown to protect mice's hearts against Ang II-induced heart damage at dosages of 20 and 40 mg/kg/d. This protection was evident in a concentration-related decrease in the remodeling of the heart and dysfunction. Examination of the transcriptome revealed that the pivotal roles in mediating the protective effects of Car involved inhibiting Ang II-induced inflammation and the activation of the mitogen-activated protein kinase (MAPK) pathway. Furthermore, Car was found to inhibit p38 phosphorylation, therefore reducing the level of inflammation in cultured cardiomyocytes and mouse hearts. This effect was attributed to the direct binding to p38 and inhibition of p38 protein phosphorylation by Car both in vitro and in vivo. In addition, the effects of Car on inflammation were neutralized when p38 was blocked in cardiomyocytes.


Asunto(s)
Abietanos , Angiotensina II , Antiinflamatorios , Ratones Endogámicos C57BL , Miocitos Cardíacos , Remodelación Ventricular , Proteínas Quinasas p38 Activadas por Mitógenos , Animales , Angiotensina II/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Masculino , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Ratones , Abietanos/farmacología , Abietanos/uso terapéutico , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Remodelación Ventricular/efectos de los fármacos , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Inflamación/inducido químicamente , Fosforilación/efectos de los fármacos , Células Cultivadas
13.
Front Psychol ; 14: 1169845, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37388659

RESUMEN

Introduction: The COVID-19 pandemic has significantly impacted global economies and individual health. This study uses data from the China Family Panel Data (CFPS) in 2018 (before the pandemic) and 2020 (during the pandemic) to a) estimate the relationships between the perceived risk of unemployment and individuals' mental health, physical health, and health behaviors; and b) explore the variations of these relationships between rural and urban adults in China. Methods: Ordinary linear regression models or Logit models are employed, depending on the nature (continuous vs. discrete) of the dependent variables. Results: We find that the perceived risk of unemployment was statistically and positively associated with the risk of depression, and the association was greater for rural adults than for urban adults. Rural-urban variations were observed in various dimensions. For rural adults, the perceived risk of unemployment was statistically and negatively associated with life satisfaction, the probability of gaining weight and becoming obese, the probability of having adequate sleep, and computer-based screen time. These associations were statistically insignificant for urban adults. On the other hand, the perceived risk of unemployment was statistically and negatively associated with self-rated very-good-to-excellent health condition and health-compromising behaviors (e.g., smoking and drinking) for urban adults; but such associations were statistically insignificant for rural adults. Discussion: These findings suggest that rural and urban adults exhibited different psychological and behavioral responses to the unemployment risk during the COVID-19 pandemic. Public policies aiming to improve health and employment should be strategically designed to address the unique needs of urban and rural populations.

14.
Cell Adh Migr ; 17(1): 1-14, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37749865

RESUMEN

The LMNA gene encoding lamin A/C is amplified in some clear cell renal cell carcinoma (ccRCC) samples. Our data showed that depletion of the tumor suppressor PBRM1 can upregulate lamin A/C levels, and lamin A/C could interact with PBRM1. However, the role of lamin A/C in ccRCC is not yet fully understood. Our functional assays showed that although the proliferation ability was slightly impaired after LMNA depletion, the migration and invasion of ccRCC cells were significantly inhibited. This suppression was accompanied by a reduction in MMP2, MMP9, AKT/p-AKT, and Wnt/ß-catenin protein levels. Our data therefore suggest that lamin A/C, as an interaction partner of the tumor suppressor PBRM1, plays a crucial role in tumor invasion and metastasis in ccRCC.


Asunto(s)
Carcinoma de Células Renales , Neoplasias Renales , Humanos , Carcinoma de Células Renales/metabolismo , Neoplasias Renales/metabolismo , beta Catenina/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Lamina Tipo A/genética , Lamina Tipo A/metabolismo , Proliferación Celular/genética , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica
15.
Injury ; 54(2): 778-783, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36481053

RESUMEN

PURPOSE: The study aimed to introduce anterior superior iliac spine distraction to treat severe and recalcitrant diabetic foot ulcers. For comparison, we also included another group of diabetic foot ulcers treated with proximal tibial cortex transverse distraction. METHODS: From February 1998 to February 2020, 87 patients (87 feet) with severe and recalcitrant diabetic foot ulcers were treated. The mean age of patients at surgery was 64 years (range, 47 to 87 years). The severity of the narrowed artery was assessed using the ankle-brachial index test. For comparison, another group of 91 patients (91 diabetic foot ulcers) treated with proximal tibial cortex transverse distraction was included. RESULTS: The mean preoperative ankle-brachial indexes of the two groups were 0.41±0.07 and 0.39±0.05 (OR 0.65 [95% CI -0.77 to 1.58]; P=0.62), respectively. The mean preoperative limb pain was 3.42±2.84 cm and 3.52±3.11 cm (OR 1.54 [95% CI -077 to 1.35]; P=0.083), respectively. At the 2-year follow-up visit, ulcers healed in 72 (83%) and 74 (81%) patients, respectively (P=0.188). The mean postoperative limb pain was 0.52±0.23 cm and 0.49±0.41 cm (OR 2.32 [95% CI -0.27 to 1.66]; P=0.078), respectively. Pin-site infection occurred in 2 patients and 8 patients (P=0.09), respectively. Ulcer recurrence occurred in 13 (15%) patients and 15 (16%) patients (P=0.205), respectively. CONCLUSIONS: Anterior superior iliac spine transverse distraction may be an effective alternative treatment for severe and recalcitrant diabetic foot ulcers. It may be associated with fewer distraction-site complications than proximal tibial cortex transverse distraction. LEVEL OF EVIDENCE: Therapeutic study, Level IIa.


Asunto(s)
Diabetes Mellitus , Pie Diabético , Humanos , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Pie Diabético/cirugía , Cicatrización de Heridas , Pie , Tibia/cirugía , Resultado del Tratamiento , Dolor
16.
Int J Rehabil Res ; 46(1): 92-97, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36727671

RESUMEN

The aim of this study is to explore the factors influencing early mobilisation behaviours and patients' needs in critically ill patients after liver transplantation (LT). This interview study used phenomenological research, and Pender's health promotion model (HPM) was used to construct the interview guide. With the use of purposeful sampling, a total of 19 critically ill patients who experienced early mobilisation after LT were recruited at three tertiary hospitals in Beijing from August to November 2022. Data were collected through semi-structured interviews and analysed using Colaizzi's seven-step method. Nine themes were categorised into the three domains of Pender's HPM. The first domain was individual characteristics and experiences: (1) symptoms of end-stage liver disease limiting premobility behaviours and (2) previous treatment experience affecting understanding of early mobilisation after LT. The second domain was behaviour-specific cognition and affect: (3) coexistence of benefits and concerns in early mobilisation after LT, (4) barriers to early mobilisation after LT, (5) high self-efficacy in early mobilisation after LT, (6) individual differences in early mobilisation and (7) support and encouragement from family, wardmates and medical staff. The final domain was behavioural outcomes: (8) the need for sufficient staff, a quiet environment, safety, goals, guidance and family participation and (9) a strong willingness to comply with early mobilisation plans. The three areas and nine themes extracted in this study are helpful for the long-term development of early mobilisation in patients after LT.


Asunto(s)
Ambulación Precoz , Trasplante de Hígado , Humanos , Enfermedad Crítica , Promoción de la Salud , Investigación Cualitativa
17.
Risk Anal ; 32(12): 2152-65, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22563722

RESUMEN

This study empirically investigates the association between country-level socioeconomic characteristics and risk of being victimized in transnational terrorism events. We find that a country's annual financial contribution to the U.N. general operating budget has a positive association with the frequency of being victimized in transnational terrorism events. In addition, per capita GDP, political freedom, and openness to trade are nonlinearly related to the frequency of being victimized in transnational terrorism events.


Asunto(s)
Terrorismo , Presupuestos , Investigación Empírica , Naciones Unidas
18.
J Environ Manage ; 95(1): 39-48, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22115509

RESUMEN

Using data from three contingent valuation studies, this study investigates if socio-economic factors and the type of good being valued can help explain changes in respondents' answers. A bias ratio, defined as the ratio of respondents who change their choice under hypothetical and "real" settings, is developed to help explain changes in respondents' answers. Marginal changes in the bias ratio resulting from a change in a particular independent variable consist of changes in responses in both the hypothetical and real situation. Results provide limited evidence that socio-economic variables and type of good being study can help in explaining bias. Respondents who are older, have a higher level of education, and are environmentally conscious tend to show less bias. Familiarity with the good also tend to decrease bias. A large amount of the variation in bias, however, remains unexplained.


Asunto(s)
Variaciones Dependientes del Observador , Animales , Conservación de los Recursos Naturales , Humanos , Modelos Estadísticos , República de Corea , Factores Socioeconómicos
19.
J AOAC Int ; 105(5): 1319-1329, 2022 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-35451477

RESUMEN

BACKGROUND: At present, the research on achiral drug and pesticide residue detection methods is still the mainstay at home and abroad, and there is still a lack of systematic research on the enantiomeric analysis of chiral drugs and pesticides. OBJECTIVE: In order to prepare a novel chiral stationary phase, whose "multi-mode" chiral separation chromatographic performance and its utility was verified. METHOD: An S-(-)-2-benzylamino-1-phenylethanol mono-derivative ß-cyclodextrin bonded stationary phase (BzCSP) was prepared based on the "thiol-ene" addition reaction. The chiral compounds including four types of chiral compounds were used as "probes," and their chiral chromatographic properties were evaluated. Furthermore, a new LC-MS/MS method for the determination of the enantiomeric residues of three chiral pesticides in five kinds of fruits and vegetables was established. RESULTS: The study found that the novel stationary phase was suitable for a variety of chromatographic modes (normal phase mode, reversed-phase mode, polar organic mode). The resolutions of hexaconazole (Hex), tebuconazole (Teb), and triticonazole (Trit) enantiomers could be up to 2.31, 1.68, and 1.48, respectively, within 30 min under reversed-phase chromatography. Based on the optimal chromatographic and mass spectrum conditions, a new LC-MS/MS quantitative method for the Hex, Teb, and Trit enantiomers was established by multi-reaction positive ion monitoring (MRM). The detection limits (LODs) of enantiomers were less than 0.89 µg/kg for Hex, 0.93 µg/kg for Teb, and 0.93 µg/kg for Trit, and the averaged recoveries of enantiomers were in the range of 75.8-106.3% for Hex, 77.4-116.3% for Teb, and 78.7-113.4% for Trit. The method had good reproducibility with the RSDs (<5%) for intraday and (<7%) for interday. CONCLUSIONS: The established method had the characteristics of good selectivity, high sensitivity, strong resistance to matrix interference, and good reproducibility. It is indicated that the stationary phase prepared by the "thiol-ene" addition reaction is a new type of multi-mode stationary phase, which has a good development value. HIGHLIGHTS: The study reported a new method for the rapid preparation of a rare "multi-mode" chiral stationary phase BzCSP based on the "thiol-ene" addition reaction and verified the practicability of BzCSP including good selectivity, high sensitivity, strong resistance to matrix interference, and good reproducibility.


Asunto(s)
Plaguicidas , beta-Ciclodextrinas , Cromatografía Líquida de Alta Presión/métodos , Cromatografía Liquida/métodos , Frutas/química , Plaguicidas/análisis , Reproducibilidad de los Resultados , Estereoisomerismo , Compuestos de Sulfhidrilo/análisis , Espectrometría de Masas en Tándem/métodos , Verduras/química , beta-Ciclodextrinas/análisis , beta-Ciclodextrinas/química
20.
Materials (Basel) ; 14(12)2021 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-34207222

RESUMEN

As a major component of lignocellulosic biomass, lignin is one of the largest natural resources of biopolymers and, thus, an abundant and renewable raw material for products, such as high-performance fibers for industrial applications. Direct conversion of lignin has long been investigated, but the fiber spinning process for lignin is difficult and the obtained fibers exhibit unsatisfactory mechanical performance mainly due to the amorphous chemical structure, low molecular weight of lignin, and broad molecular weight distribution. Therefore, different textile spinning techniques, modifications of lignin, and incorporation of lignin into polymers have been and are being developed to increase lignin's spinnability and compatibility with existing materials to yield fibers with better mechanical performance. This review presents the latest advances in the textile fabrication techniques, modified lignin-based high-performance fibers, and their potential in the enhancement of the mechanical performance.

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