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1.
J Pediatr Surg ; 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31679773

RESUMO

OBJECTIVE: Chylous ascites (CA) is a rare form of ascites that results from the leakage of lipid-rich lymph into the peritoneal cavity. In infants, CA is mostly caused by lymphatic malformation or unknown reasons. The creation of a shunt for the lymphorrhea is the last option for patients unresponsive to all other conservative treatments. Localization of the leakage is a critical problem during surgery. We applied a carbon nanoparticle suspension (CNS) in CA patients to locate the external lymphatic leakage and evaluated its utility during surgery. PATIENTS AND METHODS: Twelve infants with CA were treated in our center recently. Ten patients received laparotomy, one refused therapy, and one was cured after undergoing conservative treatment. Recently, two infants with CA received CNS in the visceral peritoneum during laparotomy. The results of the traditional procedure were compared to our innovative technique for CA to evaluate the use of CNS in treating CA. RESULTS: The features of the baseline data did not differ substantially. Location of the leakage with CNS was employed in 2 of the 10 patients whose lymphatic leakages were identified with the resolution of the refractory CA. Overall, in 5 patients, ascites was resolved successfully. The refractory CA was resolved more effectively in patients in whom the leakage site was identified with CNS than in patients in whom the leakage site could not be identified under conventional surgery. CONCLUSIONS: Injecting CNS improved the accuracy of lymphorrhagia leakage site identification and the outcomes of infants who underwent surgical treatment for refractory CA. LEVEL OF EVIDENCE: II-III.

2.
PLoS One ; 14(10): e0223650, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31622370

RESUMO

Public transit, especially urban rail systems, plays a vital role in shaping commuting patterns. Compared with census data and survey data, large-scale and real-time big data can track the impacts of urban policy implementations at finer spatial and temporal scales. Therefore, this study proposed a multi-level analytical framework using transit smartcard data to examine urban commuting dynamics in response to rail transit upgrades. The study area was Shenzhen, one of the most highly urbanized and densely populated cities in China, which provides the opportunity to examine the effects of rail transit upgrades on commuting patterns in a rapidly developing urban context. Changes in commuting patterns were examined at three levels: city, region, and individual. At the city level, we considered the average commuting time, commuting speed, and commuting distance across the whole city. At the region level, we analyzed changes in the job accessibility of residential zones. Finally, this study evaluated the potential effects of rail transit upgrades on the jobs-housing relationship at the individual level. Difference-in-difference models were used for causal inference between rail transit upgrades and commuting patterns. In the very short term, the opening of new rail transit lines resulted in no significant changes in overall commuting patterns across the whole city; however, two effects of rail transit upgrades on commuting patterns were identified. First, rail transit upgrades enhanced regional connectivity between residential zones and employment centers, thus improving job accessibility. Second, rail transit improvement increased the commuting distances of individuals and contributed to the separation of workplaces and residences. This study provides meaningful insights into the effects of rail transit upgrades on commuting patterns.

4.
Hortic Res ; 6: 90, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31645948

RESUMO

[This corrects the article DOI: 10.1038/s41438-019-0142-6.].

5.
Artigo em Inglês | MEDLINE | ID: mdl-31588954

RESUMO

BACKGROUND: There remains a relative paucity of evidence for the association between changes in depressive symptoms with cardiovascular disease (CVD) and mortality. This study aimed to evaluate the association of change in depressive symptoms and incident CVD and mortality in a large prospective cohort of middle-aged and older adults. METHODS: A total of 6,810 participants free of CVD in the China Health and Retirement Longitudinal Study with two assessments of depressive symptoms at wave 1 (2011-2012) and wave 2 (2013-2014) were included. Elevated depressive symptoms were defined as a score of ≥ 12 on the 10-item Center for Epidemiologic Studies Depression scale. We used a modified Poisson regression to examine the association of changes in depressive symptoms (never, onset, remitted, and persistent) and incident CVD (a composite endpoint of heart disease or stroke) and mortality at wave 3 (2015-2016). RESULTS: During follow-up, 457 CVDs and 148 deaths occurred. Multivariable analyses revealed that persistent depressive symptoms were associated with an elevated risk of CVD (risk ratio [RR] 1.77, 95% CI 1.38-2.26) and mortality (RR 1.63, 95% CI 1.01-2.64) compared with participants without any depressive symptoms. New-onset depressive symptoms increased the mortality risk (RR 2.37, 95% CI 1.52-3.69), but not CVD (RR 1.15, 95% CI 0.84-1.58). Remitted depressive symptoms were associated with a 35% and 13% excess risk of CVD and mortality, respectively. CONCLUSION: Persistent and remitted depressive symptoms were associated with an increased risk of CVD. New-onset depressive symptoms predicted elevated mortality risk.

6.
Rev Sci Instrum ; 90(9): 096102, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31575218

RESUMO

In order to obtain the high velocity in compact size, a piezoelectric stick-slip linear actuator is proposed in this paper. The proposed actuator adopts rhombus-type flexure hinge mechanism which can be used as a displacement amplifier which can easily produce a parasitic motion. The working principle of the proposed actuator is discussed, and the finite element method is adopted to verify the generation of parasitic motion of the flexure hinge mechanism. A prototype is manufactured to investigate the working performance. The prototype achieves a maximum velocity of 13.08 mm/s at a frequency of 570 Hz under the sawtooth wave exciting voltage of 100 Vp-p. The maximum efficiency is about 1.26% with a load of 135 g and velocity of 7.12 mm/s.

7.
Spectrochim Acta A Mol Biomol Spectrosc ; 225: 117506, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31494381

RESUMO

In this study, by coupling benzothiazole and spiropyrans, three fluorescent probes HBT-pH 1, HBT-pH 2, and HBT-pH 3 were developed for pH variation monitoring. All these probes exhibited remarkable changes of absorption and emission accompanying its protonation under acidic conditions. HBT-pH 1 exhibited OFF-ON response when pH value was changed from 12.00 to 2.02, whereas ratiometric responses (large Stokes shifts) were obtained for HBT-pH 2 and HBT-pH 3. The response was attributed to the open-loop of spiropyran under acidic conditions, which was confirmed by 1H NMR. The pKa values of 6.57, 4.90, and 3.95 were obtained for HBT-pH 1, HBT-pH 2, and HBT-pH 3, respectively, indicating they were suitable for pH variation monitoring. Furthermore, low cytotoxicity and cell imaging of pH changes with HBT-pH 2 in living cells were successfully demonstrated, suggesting potential application in early diagnosis of pH-related diseases.

8.
Phys Rev Lett ; 123(5): 051101, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31491288

RESUMO

We report on the highest energy photons from the Crab Nebula observed by the Tibet air shower array with the underground water-Cherenkov-type muon detector array. Based on the criterion of a muon number measured in an air shower, we successfully suppress 99.92% of the cosmic-ray background events with energies E>100 TeV. As a result, we observed 24 photonlike events with E>100 TeV against 5.5 background events, which corresponds to a 5.6σ statistical significance. This is the first detection of photons with E>100 TeV from an astrophysical source.

9.
Opt Express ; 27(16): 22393-22407, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31510534

RESUMO

High-power fiber lasers have been widely explored in engineering and science, and improving the beam quality restricted by transverse mode instability (TMI) is waiting to be solved for extra high-power applications. Here, we theoretically propose a phase transition model for understanding TMI in a fiber oscillator. A general dynamics model describing TMI is established by modifying the heat equation, and then a special dynamics model of a two-mode fiber (TMF) oscillator is obtained by applying this general dynamics model to TMF oscillator case. Theoretical analysis shows that there is a reversible phase transition point in this TMF oscillator model, which can well explain the sudden and reversible change of TMI. Based on linear stability analysis near the phase transition point, an analytical threshold formula of TMI is given to calculate the TMI threshold in the TMF oscillator. The calculated results are consistent with the reported experimental results. Furthermore, the relationship between the TMI threshold and several parameters was also discussed in detail such as laser wavelength, pump wavelength, core radius, cladding radius, etc. This theoretical model will be useful to understand and suppress the TMI in fiber oscillators.

10.
Artigo em Inglês | MEDLINE | ID: mdl-31470512

RESUMO

Background: The aims of this study were to determine the prevalence of deliberate self-harm (DSH) and to compare the risk of self-harm in Chinese children with different types and severity of disabilities. Methods: Participants were 1300 children aged 6-17 years in Beijing, China; 650 children with disabilities and 650 healthy peers matched on age, gender and residence district. Questionnaires were completed anonymously by parents or children if the age or disability made it necessary. The associations between the disability type, severity and DSH were examined using the Chi-square testing and logistic regression models. Results: Children with a single disability or multiple disabilities had statistically higher rates of DSH than children without disabilities (15.6% and 39.7% compared to 10.9%). The prevalence of DSH was associated with the severity of disability, being 36.2% among children with level 1 (the most severe) disability, 19.8% among children with level 2 disability, and 9.2% among children with level 3 + 4 disability. The multivariable odds ratio (OR) of DSH among children with any disability was statistically higher than that among children without a disability (OR = 2.40; 95% CI = 1.71, 3.36; p < 0.05). Children with multiple disabilities (OR = 6.89; 95% CI: 4.24-11.20) and level 1 severity of disability (OR = 6.11; 95% CI: 3.91-9.56) had the highest risk of DSH. Conclusions: This study clearly demonstrated associations between the severity and type of disability and DSH. This finding highlights the importance of DSH in children with disabilities, and underlines the importance of the prevention of DSH among a vulnerable pediatric population in China.

11.
Sports Med ; 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31529300

RESUMO

BACKGROUND: Besides physical activity as a target for dementia prevention, sedentary behaviour is hypothesized to be a potential target in its own right. The rising number of persons with dementia and lack of any effective treatment highlight the urgency to better understand these modifiable risk factors. Therefore, we aimed to investigate whether higher levels of sedentary behaviour are associated with reduced global cognitive functioning and slower cognitive decline in older persons without dementia. METHODS: We used five population cohorts from Greece, Australia, USA, Japan, and Singapore (HELIAD, PATH, SALSA, SGS, and SLAS2) from the Cohort Studies of Memory in an International Consortium. In a coordinated analysis, we assessed the relationship between sedentary behaviour and global cognitive function with the use of linear mixed growth model analysis (mean follow-up range of 2.0-8.1 years). RESULTS: Baseline datasets combined 10,450 older adults without dementia with a mean age range between cohorts of 66.7-75.1 years. After adjusting for multiple covariates, no cross-sectional association between sedentary behaviour and cognition was found in four studies. One association was detected where more sedentary behaviour was cross-sectionally linked to higher cognition levels (SLAS2, B = 0.118 (0.075; 0.160), P < 0.001). Longitudinally, there were no associations between baseline sedentary behaviour and cognitive decline (P > 0.05). CONCLUSIONS: Overall, these results do not suggest an association between total sedentary time and lower global cognition in older persons without dementia at baseline or over time. We hypothesize that specific types of sedentary behaviour may differentially influence cognition which should be investigated further. For now, it is, however, too early to establish undifferentiated sedentary time as a potential effective target for minimizing cognitive decline in older adults without dementia.

12.
Acta Biomater ; 2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31525534

RESUMO

PURPOSE: Encapsulated microbubbles (MBs) have been reported as new theranostic carriers for simultaneous imaging and ultrasound (US)-triggered therapy. Here, we designed a dual-modality US/NIRF contrast agent and extended its applications from image contrast enhancement to combined diagnosis and therapy with US-directed and site-specific targeting. METHODS: Gold nanorods (AuNRs) resonant at 880 nm together with the NIR797 dye were first encapsulated in lipid-shelled MBs to construct fluorescent gold microbubbles (NIR797/AuMBs) via thin film hydration and mechanical shaking in the presence of sulfur hexafluoride (SF6) gas. Then, polyethylenimine (PEI)-DNA complexes were electrostatically conjugated onto the surface of the NIR797/AuMBs, forming theranostic encapsulated MBs (PEI-DNA/NIR797/AuMBs). The potential of the PEI-DNA/NIR797/AuMBs for use as a dual-modality contrast enhancement agent was evaluated in vitro and in vivo. The antitumor effect of US/NIR laser irradiation mediating double-fusion suicide gene and photothermal therapy was also investigated using Bel-7402 cells and xenografts. RESULTS: The developed theranostic AuMB complexes could not only provide excellent US and NIRF imaging to detect tumors but also serve as an efficient US-triggered carrier for gene delivery and photothermal ablation of tumors in xenografted nude mice. And US + laser exposure group showed a much higher rate of cell inhibition, apoptosis and necrosis as well as a higher Bel-7402 xenograft inhibition rate than the single gene therapy or single exposure (US or laser) group. CONCLUSIONS: PEI-DNA/NIR797/AuMBs would be of great value for providing more comprehensive diagnostic information and to guide more accurate and effective synergistic cancer therapy. STATEMENT OF SIGNIFICANCE: This is an original paper focusing on developing a dual-modality US/NIRF contrast agent and extended its applications from image contrast enhancement to combined diagnosis and therapy with US-directed and site-specific targeting. The developed theranostic AuMB complexes could not only provide excellent US and NIRF imaging to detect tumors but also serve as an efficient US-triggered carrier for gene delivery and photothermal ablation of tumors in xenografted nude mice. PEI-DNA/NIR797/AuMBs would be of great value for providing more comprehensive diagnostic information and to guide more accurate and effective synergistic cancer therapy.

13.
PLoS One ; 14(9): e0222035, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31504073

RESUMO

CDK2-associated cullin domain 1 (CAC1) is as a novel cell cycle regulator widely expressed in colorectal cancer (CRC). However, its expression and function in drug resistant CRC cells remains elusive. Therefore, the present study aimed to assess the biochemical function and relevance of CAC1 in drug resistant CRC cells, and detect the potential mechanism. For this purpose, a total of 83 CRC cases were collected for the immunohistochemical analysis of CAC1 expression. Functional studies (stable transfection, flow cytometry, colony formation, and invasion and migration assays) were performed in SW480, LoVo and their corresponding 5-FU resistant cells. In addition, a nude mice xenograft model was established for further observation in vivo. In the present study, CAC1 protein expression was higher in CRC tissues than that in normal tissues (P<0.05). Furthermore, CAC1 protein expression was higher in SW480/5-FU cells than in SW480 cells. CAC1 knockdown arrested 5-FU resistant cells at the G1/S phase and increased the sensitivity of 5-FU resistant cells to 5-FU by inducing apoptosis. In addition, CAC1 reduced the invasive and migration ability of SW480/5-FU and LoVo/5-FU cells in vitro, and reduced their tumorigenicity and metastatic ability in vivo. Finally, CAC1 knockdown resulted in decreased P-glycoprotein and MRP-1 protein expression. Based on these results, it can be concluded that CAC1 plays an important role in the occurrence and promotion of drug resistance in CRC. Therefore, the knockdown of CAC1 may be considered as a new strategy for the development of CRC drug resistance treatments in the future.

14.
Virology ; 537: 1-13, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31425969

RESUMO

Viral spread is considered a promising target for antiviral therapeutics, but the associated mechanisms remain unclear for gallid alpha herpesvirus 1 (ILTV). We previously identified proto-oncogene tyrosine-protein kinase Src (Src) as a crucial host determinant of ILTV infection. The present study revealed accelerated spread of ILTV upon Src inhibition. This phenomenon was independent of either viral replication or the proliferation of infected cells and could not be compromised by neutralizing antibody. Neither extracellular vesicles nor the direct cytosol-to-cytosol connections between adjacent cells contributed to the enhanced spread of ILTV upon Src inhibition. Further genome-wide transcriptional profile analyses in combination with functional validation identified fatty acid metabolism as an essential molecular event during modulation of the intercellular spread and subsequent cytopathic effect of ILTV by Src. Overall, these data suggest that Src controls the cell-to-cell spread of ILTV in a cellular fatty acid metabolism-dependent manner, which determines the virus's cytopathic effect.

15.
Sci Total Environ ; 695: 133875, 2019 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-31421340

RESUMO

The surface functional group plays an important role in H2S catalytic oxidization. However, the specific effect of each group species has seldom been investigated. For the first time, we revealed by experimental and theoretical methods that the pyrone group was the most valuable group. An increase in the pyrone-group amount obviously decreased the kinetic reaction order of H2S catalytic oxidization. The catalyst with the largest amount of pyrone group (0.1321 mmol·g-1) showed the lowest reaction order (0.5896) and activation energy (16.25 kJ·mol-1). By comparison, a catalyst with 0.0008 mmol·g-1 of pyrone group had a reaction order of just 1.1852 and an activation energy of 81.22 kJ·mol-1. The contribution of pyrone content to the kinetic reaction order had a negative correlation coefficient of -8.0665, which was three and five times larger than that of the quinone (-2.5568) and acidic groups (-1.7454), respectively. Moreover, density functional theory calculations showed that the pyrone group had the lowest energy gap (0.156 eV), far less than that (1.921 eV) of the carboxyl group. After H2S was adsorbed, the pyrone group had a Mulliken atomic charge of 0.510, which was larger than that (0.236) of the carboxyl group. In other words, the pyrone group showed the best ability to facilitate electron transfer. As a result, the catalyst with 0.1321 mmol·g-1 of the pyrone group removed 100% of the H2S (450 ppm). This amount was 42% higher than a catalyst with 0.0008 mmol·g-1 of the pyrone group. The main results of this work help to explain the mechanism of carbon material in various types of catalysis.

16.
Mol Immunol ; 112: 387-393, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31288148

RESUMO

Programmed cell death 4 (Pdcd4) was found to be related to apoptosis upon first discovery. It was later found to play the role of tumor suppressor gene in a variety of tumors by inhibiting transcription and translation. Recently, it has been proposed that it may play an important role in some inflammatory diseases and in the immune response. In our previous study, deficiency of Pdcd4 was found to attenuate the formation of atherosclerotic plaques. This might be because deficiency of Pdcd4 may increase IL-10 expression and lipoautophagy by macrophages and attenuate the formation of foam cells. However, the effect of Pdcd4 on the subsets of T cells in hyperlipidemic mice still remained unclear. In the present study, results showed that Pdcd4 deficiency decreased the percentage of CD8+ T cells and increased that of regulatory T cells (Tregs) under hyperlipidemic conditions both in vitro and in vivo, which may be due to the reduced expression of co-stimulatory molecules CD28 and CD137, and the enhancive expression of co-inhibitory molecules CTLA-4. These results indicated that endogenous Pdcd4 promotes immune response mediated by T cells through regulation of the co-stimulatory molecules expression, which may contribute to the development of advanced atherosclerotic plaques. The current work provides new data to understand the role of Pdcd4 in different T cell subsets under hyperlipidemic microenvironment.


Assuntos
Proteínas Reguladoras de Apoptose/deficiência , Proteínas Reguladoras de Apoptose/metabolismo , Hiperlipidemias/metabolismo , Proteínas de Ligação a RNA/metabolismo , Subpopulações de Linfócitos T/metabolismo , Animais , Apoptose/fisiologia , Antígenos CD28/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Células Espumosas/metabolismo , Interleucina-10/metabolismo , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Placa Aterosclerótica/metabolismo , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo
17.
PLoS Med ; 16(7): e1002853, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31335910

RESUMO

BACKGROUND: With no effective treatments for cognitive decline or dementia, improving the evidence base for modifiable risk factors is a research priority. This study investigated associations between risk factors and late-life cognitive decline on a global scale, including comparisons between ethno-regional groups. METHODS AND FINDINGS: We harmonized longitudinal data from 20 population-based cohorts from 15 countries over 5 continents, including 48,522 individuals (58.4% women) aged 54-105 (mean = 72.7) years and without dementia at baseline. Studies had 2-15 years of follow-up. The risk factors investigated were age, sex, education, alcohol consumption, anxiety, apolipoprotein E ε4 allele (APOE*4) status, atrial fibrillation, blood pressure and pulse pressure, body mass index, cardiovascular disease, depression, diabetes, self-rated health, high cholesterol, hypertension, peripheral vascular disease, physical activity, smoking, and history of stroke. Associations with risk factors were determined for a global cognitive composite outcome (memory, language, processing speed, and executive functioning tests) and Mini-Mental State Examination score. Individual participant data meta-analyses of multivariable linear mixed model results pooled across cohorts revealed that for at least 1 cognitive outcome, age (B = -0.1, SE = 0.01), APOE*4 carriage (B = -0.31, SE = 0.11), depression (B = -0.11, SE = 0.06), diabetes (B = -0.23, SE = 0.10), current smoking (B = -0.20, SE = 0.08), and history of stroke (B = -0.22, SE = 0.09) were independently associated with poorer cognitive performance (p < 0.05 for all), and higher levels of education (B = 0.12, SE = 0.02) and vigorous physical activity (B = 0.17, SE = 0.06) were associated with better performance (p < 0.01 for both). Age (B = -0.07, SE = 0.01), APOE*4 carriage (B = -0.41, SE = 0.18), and diabetes (B = -0.18, SE = 0.10) were independently associated with faster cognitive decline (p < 0.05 for all). Different effects between Asian people and white people included stronger associations for Asian people between ever smoking and poorer cognition (group by risk factor interaction: B = -0.24, SE = 0.12), and between diabetes and cognitive decline (B = -0.66, SE = 0.27; p < 0.05 for both). Limitations of our study include a loss or distortion of risk factor data with harmonization, and not investigating factors at midlife. CONCLUSIONS: These results suggest that education, smoking, physical activity, diabetes, and stroke are all modifiable factors associated with cognitive decline. If these factors are determined to be causal, controlling them could minimize worldwide levels of cognitive decline. However, any global prevention strategy may need to consider ethno-regional differences.

18.
Nutrition ; 66: 180-186, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31310959

RESUMO

OBJECTIVES: Older adults who are malnourished are at high risk for adverse functional and mortality outcomes. The aim of this study was to assess the long-term changes in nutritional status among community-living older adults and their associations with adverse health outcomes. METHODS: This was a population-based observational cohort study (Singapore Longitudinal Aging Study, SLAS 1), with a 4- to 5-y follow-up of 2075 community-living adults ≥60 y of age. Nutritional status (Mini Nutritional Assessment Short-Form [MNA-SF] and Nutritional Screening Initiative [NSI]), instrumental/basic activities of daily living (IADLs/ADLs) and quality of life (QoL) were assessed at both baseline and at the 4- to 5-y follow-up. The 10-y mortality was assessed from the date of 4- to 5-y follow-up to March 2017. Estimates of associations between changes in nutritional status and adverse health outcomes were analyzed using multinomial logistic regression or Cox proportional hazards regression, and indicated by odds ratios/hazard ratios (ORs/HRs) and 95% confidence intervals (CIs). RESULTS: Nutritional status was dynamic from baseline to the 4- to 5-y follow-up according to both MNA-SF and NSI. Compared with persistent normal nutrition, nutritional deterioration was associated with increased incident IADL/ADL disability (MNA-SF: OR, 3.22; 95% CI, 1.13-9.16), poor QoL (MNA-SF: OR, 4.53; 95% CI 2.13-9.64), and mortality (MNA-SF: HR, 4.76; 95% CI, 2.82-8.03; NSI: HR, 1.99; 95% CI, 1.27-3.14); nutritional improvement was associated with decreased incident IADL/ADL disability (NSI: OR, 0.17; 95% CI, 0.05-0.59); persistent poor nutrition (MNA-SF at risk/malnourished or NSI moderate/high nutritional risk) was associated with elevated incidence of poor QoL (MNA-SF: OR, 1.92,; 95% CI, 1.05-3.52; NSI: OR, 2.31; 95% CI, 1.19-4.49) and mortality (MNA-SF: HR, 2.57; 95% CI, 1.59-4.15; NSI: HR 1.97; 95% CI, 1.17-3.32). Compared with persistent poor nutrition, nutritional improvement was also associated with decreased incidence of mortality (MNA-SF: HR, 0.43; 95% CI, 0.23-0.80). CONCLUSIONS: Changes in nutritional status are associated with adverse health outcomes, and should be monitored with simple screening tools to identify older adults at high risk for adverse functional and mortality outcomes for selective nutritional interventions.

19.
J Org Chem ; 84(16): 10024-10031, 2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31283876

RESUMO

Retro-Brook rearrangements refer to the intramolecular migration of a silyl group from oxygen to carbon. In this study, we report a novel propargylic retro-Brook rearrangement observed in terminal alkynes bearing a silyl ether moiety. Retro-Brook rearrangements involving [1,2]-, [1,4]-, and [1,5]-migrations are described, affording propargylsilanes in reasonable yield. The reaction mechanism was investigated experimentally by deuterium quenching and rationalized by density functional theory calculations. The terminal alkyne and the subsequent propargyl/allenyl dianion were shown to be crucial for the reaction favoring the retro-Brook rearrangement product over the Brook rearrangement. The second deprotonation at the propargylic position was determined to be the rate-limiting step. In addition, a gas-phase Brook-type rearrangement of the propargylsilanes was observed under GC-MS conditions. This observation was also further confirmed by DFT calculations.

20.
AAPS PharmSciTech ; 20(6): 219, 2019 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-31201583

RESUMO

Hydroxypropyl methylcellulose (HPMC) is a hydrophilic retarding-release polymer with the limited application in hot melt extrusion (HME) due to its high glass transition temperature (Tg 181-191°C) and melt viscosity. The aim of this study is to develop hot melt extruded matrices using hydroxypropyl cellulose (HPC) and felodipine (FLDP) with HPMC for controlled release and explore the relations of their specialty, processability, and structure with the product properties. Results showed that FLDP/HPCEF/HPMC can be extruded at 160°C with torques not more than 0.5 N·m. The extruded matrices of FLDP/HPCEF/HPMCK15M (10:45:45 and 30:35:35) achieved the controlled release for 24 h. Rheological behaviors demonstrated that HPCEF and FLDP were miscible with HPMCK15M, attaining maximum 30% FLDP soluble in the molten mixtures. HPCEF and FLDP decreased the complex viscosity and plasticized HPMCK15M to improve the extrusion processing. DSC and FT-IR indicated that the molten soluble FLDP was amorphous in the extruded matrices by hydrogen bonding with HPCEF/HPMCK15M. SEM/energy-dispersive X-ray microanalysis illustrated that the microstructure of extrudates was surface dense and interior loose, and FLDP was homogenously dispersed. Three-point bending test revealed that the plasticizers of HPCEF and FLDP contributed differently to the mechanical properties. HPCEF decreased the flexural modulus of HPMCK15M while that of HPCEF/HPMCK15M was increased by FLDP. Besides controlled release, low moisture absorption and enhanced stability were also the correlated achievements. Therefore, HPCEF-combined poorly water-soluble drugs to plasticize HPMCK15M provide an alternative novel potential approach to realize the controlled-release delivery via HME.


Assuntos
Preparações de Ação Retardada , Felodipino/química , Derivados da Hipromelose/química , Plastificantes/química , Química Farmacêutica/métodos , Temperatura Alta , Polímeros/química , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Viscosidade
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