Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Arch Environ Contam Toxicol ; 86(4): 325-334, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38664243

RESUMO

We examined the conception rate of wild Japanese monkeys (Macaca fuscata) in Fukushima City that were exposed to radiation as a result of the Fukushima Daiichi Nuclear Power Plant accident in March 2011. The conception rate in the year of delivery from 2009 to 2022 was estimated by dissecting individuals that were euthanized by the government for population control as a countermeasure against crop damage. To evaluate the effects of exposure, the cumulative exposure dose for each individual was calculated using the concentration of radiocesium deposited in the soil at the capture site and the concentration of radiocesium in muscle estimated from the aggregated transfer factor. There were no significant differences in conception rates across all age classes over time. In terms of conception rates by age class, there was a significant decrease post-exposure compared with pre-exposure in the age class ≥ 8 years, but no significant differences in the age class 5-7 years. The non-ovulation rate did not significantly differ between the pre- and post-exposure periods for any age class. Body fat index, which can affect fertility, was compared between the pre- and post-exposure periods, and no significant differences were found in either age class. In contrast, the median total cumulative exposure (cumulative internal exposure + cumulative external exposure) was significantly higher in the age class ≥ 8 years compared with the age class 5-7 years. These results suggest that the total cumulative exposure dose may be one of the reasons for the lower conception rate in the post-exposure period among the age class ≥ 8 years.


Assuntos
Radioisótopos de Césio , Fertilização , Acidente Nuclear de Fukushima , Macaca fuscata , Animais , Radioisótopos de Césio/análise , Japão , Fertilização/efeitos dos fármacos , Feminino , Monitoramento de Radiação , Poluentes Radioativos do Solo/análise
2.
J Hum Nutr Diet ; 37(3): 762-771, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38534044

RESUMO

BACKGROUND: This study examined the effects of animal protein- and plant protein-rich diets on postprandial phosphorus metabolism in healthy male subjects. METHODS: The study was conducted by randomised parallel-group comparison of healthy men aged 21-24 years. In Study 1, participants were divided into two groups and consumed either a 70% animal protein diet (AD, n = 6) or a 70% plant protein diet (PD, n = 6). In Study 2, participants were divided into three groups and consumed either AD (n = 10), PD (n = 10) or AD + DF, a 70% animal protein diet loaded with the same amount of fibre as PD (n = 9). The phosphorus contents of the diets used in this study were nearly equivalent (AD, 710.1 mg; PD, 709.7 mg; AD + DF, 708.9 mg). Blood and urine samples were collected before, and 2 and 4 h after the meal to measure phosphorus and calcium levels. RESULTS: In Study 1, PD consumption resulted in lower blood and urinary phosphorus concentrations 2 h postprandially compared with AD (p < 0.05). In Study 2, blood phosphorus levels in AD + DF after the diet remained lower, but not significantly so compared with AD, and urinary phosphorus levels were significantly lower 2 h postprandially (p < 0.05). CONCLUSIONS: A plant protein-rich diet reduced rapid postprandial increases in blood and urinary phosphorus concentrations compared with the animal protein-rich diets, suggesting that dietary fibre may play a partial role in the postprandial decreases in blood and urinary phosphorus concentrations.


Assuntos
Período Pós-Prandial , Humanos , Masculino , Adulto Jovem , Fibras na Dieta/administração & dosagem , Proteínas Animais da Dieta , Fosfatos/sangue , Fosfatos/urina , Cálcio/sangue , Cálcio/urina , Fósforo/sangue , Fósforo/urina , Proteínas de Vegetais Comestíveis/administração & dosagem , Adulto , Dieta/métodos , Proteínas de Plantas/administração & dosagem
3.
Radiat Res ; 198(2): 200-203, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35604872

RESUMO

Microtubules, one of the cytoskeletons, are highly dynamic structures that play a variety of roles in maintaining cell morphology, cell division and intracellular transport. Microtubules are composed of heterodimers of α- and ß-tubulins, which are repeatedly polymerized and depolymerized. To investigate the radiation-induced impacts on the polymerization reaction of tubulins, we evaluated the molecular interactions between normal and irradiated tubulins. First, the polymerization reaction of the tubulins was measured after stepwise irradiation from 0 Gy to 1,000 Gy of X rays. The polymerization was inhibited in a dose-dependent manner. Next, the tubulins' polymerization reaction was then measured after the tubulin that was damaged from the exposure to 1,000 Gy of X rays was mixed with the normal tubulins. Our findings reveal that the radiation dose-dependent change in the degree of overall microtubule polymerization progression depends on the ratio of damaged tubulin. This result is biochemical evidence that non-DNA damage (in this case, cytoskeletal damage) from cytoplasmic radiation exposure may inhibit cell division, suggesting that some cytoskeletal damage may also affect the fate of the entire cell.


Assuntos
Microtúbulos , Tubulina (Proteína) , Citoplasma , Citoesqueleto , Microtúbulos/química , Polimerização , Tubulina (Proteína)/genética
4.
Opt Express ; 30(6): 9473-9481, 2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35299374

RESUMO

Optical parametric amplification in the range of 1.3-1.8 µm was demonstrated by using a periodically poled LiNbO3 (PPLN) waveguide as a nonlinear medium by varying the detuning of the pump wavelength. A wide range of detuning was enabled by using a multiple-quasi-phase-matched (M-QPM) LiNbO3 waveguide for pump generation through second harmonic generation (SHG) and temperature control of the PPLN waveguide. Broadband optical amplification and wavelength conversion through difference frequency generation (DFG) are considered useful for widening the bandwidth of optical communication.

5.
Phys Chem Chem Phys ; 23(36): 20313-20322, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34486597

RESUMO

Reverse osmosis (RO) is a widely used energy-efficient separation technology for water treatment. Polyamide (PA) membranes are the conventional choice for this process. Fouling is a serious problem for RO separation. This issue leads to significant decreases in the water permeability of PA membranes, and it has yet to be fully elucidated. In particular, the fouling behavior of a nonionic substance on the negatively charged surface of a PA membrane in an aqueous environment has not been previously studied. In this work, the mechanisms of nonionic substances such as polyoxyethylene octyl ether (PE5) and maltose (Mal) were investigated using molecular dynamics (MD) simulations. In a PA membrane in which the carboxyl group was not dissociated, the hydrophobic portion of the membrane was exposed due to the localization of water molecules around the carboxyl groups in the PA membrane. This caused hydrophobic interaction with the hydrophobic groups of PE5. In the case of an amine-modified PA membrane containing no carboxyl groups, water was not localized around the functional group, and the water orientation of the polyamide surface was also low. Due to this membrane property, the presence of stabilized water around PE5 reduced the number of hydrophobic interactions. In similar manner, a PA membrane with a slightly dissociated carboxyl group was hydrophilic, which reduced the PE5 adsorption. The presence of many dissociated carboxyl groups, however, enhanced the adsorption of PE5 due to the increase in interactions between the dissociated carboxyl groups and the hydrophilic groups of PE5. Therefore, PE5 exhibited an amphipathic adsorption wherein both hydrophilic and hydrophobic groups contributed to adsorption onto the PA membrane. Mal, on the other hand, was highly stable in every aqueous environment independent of the state of the functional groups of the PA membrane, and was not easily affected by the properties of the PA membrane.

6.
Nano Lett ; 21(15): 6525-6532, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34339209

RESUMO

A highly permselective nanofiltration membrane was engineered via zwitterionic copolymer assembly regulated interfacial polymerization (IP). The copolymer was molecularly synthesized using single-step free-radical polymerization between 2-methacryloyloxyethyl phosphorylcholine (MPC) and 2-aminoethyl methacrylate hydrochloride (AEMA) (P[MPC-co-AEMA]). The dynamic network of P[MPC-co-AEMA] served as a regulator to precisely control the kinetics of the reaction by decelerating the transport of piperazine toward the water/hexane interface, forming a polyamide (PA) membrane with ultralow thickness of 70 nm, compared to that of the pristine PA (230 nm). Concomitantly, manipulating the phosphate moieties of P[MPC-co-AEMA] integrated into the PA matrix enabled the formation of ridge-shaped nanofilms with loose internal architecture exhibiting enhanced inner-pore interconnectivity. The resultant P[MPC-co-AEMA]-incorporated PA membrane exhibited a high water permeance of 15.7 L·m-2·h-1·bar-1 (more than 3-fold higher than that of the pristine PA [4.4 L·m-2·h-1·bar-1]), high divalent salt rejection of 98.3%, and competitive mono-/divalent ion selectivity of 52.9 among the state-of-the-art desalination membranes.


Assuntos
Membranas Artificiais , Polímeros , Nylons , Polimerização , Água
7.
J Vet Med Sci ; 83(9): 1389-1394, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34234069

RESUMO

The Shimokita Peninsula in Aomori Prefecture, Japan, which is inhabited by Japanese monkeys (Macaca fuscata), is the northernmost habitat for wild primates in the world. This study was the first to determine the conception dates of specific individuals and estimate the pregnancy rate of wild populations in this region. The pregnancy rate of animals aged 5 years or more at delivery was estimated to be 40.9% (27/66). Conception dates of each fetus were also estimated using a regression line of Pig-tail monkeys (Macaca nemestrina), which are taxonomically related to Japanese monkeys and have a similar physique. The conception dates were distributed across 90 days between September 24th and December 23rd, with a mean conception date of November 4th (SD=22.3 days, n=53). Using these findings, the mean birth date was estimated as April 25th, more than two weeks earlier than the mean birth date in previous research determined using direct observations carried out over the past 20 years ago. Global warming due to climate change is thought to be one of the main causes of this difference.


Assuntos
Macaca fuscata , Macaca , Animais , Ecossistema , Feminino , Japão , Gravidez , Primatas
8.
Front Cell Dev Biol ; 9: 640399, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33732705

RESUMO

Glucose is a major energy source consumed by proliferating mammalian cells. Therefore, in general, proliferating cells have the preference of high glucose contents in extracellular environment. Here, we showed that high glucose concentrations impede the proliferation of satellite cells, which are muscle-specific stem cells, under adherent culture conditions. We found that the proliferation activity of satellite cells was higher in glucose-free DMEM growth medium (low-glucose medium with a glucose concentration of 2 mM) than in standard glucose DMEM (high-glucose medium with a glucose concentration of 19 mM). Satellite cells cultured in the high-glucose medium showed a decreased population of reserve cells, identified by staining for Pax7 expression, suggesting that glucose concentration affects cell fate determination. In conclusion, glucose is a factor that decides the cell fate of skeletal muscle-specific stem cells. Due to this unique feature of satellite cells, hyperglycemia may negatively affect the regenerative capability of skeletal muscle myofibers and thus facilitate sarcopenia.

9.
ACS Appl Mater Interfaces ; 12(34): 38662-38673, 2020 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-32693571

RESUMO

In this study, custom-tailored graphene oxide quantum dots (GOQD) were synthesized as functional nanofillers to be embedded into the polyamide (PA) membrane for reverse osmosis (RO) via interfacial polymerization (IP). The heterostructured interface-functionalization of amine/sulfonic decoration on GOQD (N/S-d-GOQD) takes place via the tuning of the molecular design. The embedded N/S-d-GOQD inside the PA matrix contributes to facilitating water molecules quick transport due to the more accessible capturing sites with higher internal polarity, achieving a nearly 3-fold increase in water permeance when compared to the pristine thin-film composite (TFC) membrane. Covalent bonding between the terminal amine groups and the acyl chloride of trimesoyl chloride (TMC) enables the formation of an amplified selective layer, while the sulfonic part assists in maintaining a robust membrane surface negative charge, thus remarkably improving the membrane selectivity toward NaCl. As a result, the newly developed TFN membrane performed remarkably high water permeance up to 5.89 L m-2 h-1 bar-1 without the compromising of its favorable salt (NaCl) rejection ratio of 97.1%, revealing a comparably high separation property when comparing to the state-of-the-art RO membranes, and surpassing the permeability-selectivity trade-off limits. Furthermore, we systematically investigated the GOQDs with different surface decorations but similar configurations (including 3 different nanofillers of pristine GOQD, amine decorated GOQD (N-d-GOQD), and N/S-d-GOQD) to unveil the underlying mechanisms of the swing effects of internal geometry and polarity of the embedded nanofillers on contributing to the uptake, and/or release of aqueous molecules within TFN membranes, providing a fundamental perspective to investigate the impact of embedded nanofillers on the formation of an IP layer and the overall transporting behavior of the RO process.

10.
J Back Musculoskelet Rehabil ; 33(4): 553-560, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32444533

RESUMO

BACKGROUND: Previous studies have examined when activities of daily living (ADL) recovery more than six months after surgery can be predicted, and how much accuracy the predictors have. OBJECTIVE: The purpose of this study was to determine the predictors of ADL decline and evaluate their accuracies one year post-operation for hip-fracture patients. METHODS: We studied patients who underwent hip fracture surgery and were able to walk independently pre-operatively. The predictors of ADL declined one year post-operation, as analyzed using data of the basic medical attributes of the patients, including pain, 30-s chair-stand test, dementia [using the Revised Hasegawa Dementia Scale (HDS-R)], and walking/mobility style [using Barthel Index (BI)]. Using a receiver operating curve (ROC) curve, the cut-off value for each significant predictor was determined in the logistic regression analysis. To calculate the cut-off values and diagnostic performances of each of the extraction factors. RESULTS: The data of 36 patients were collected over a period of one year. The prior probability of ADL decline at one year post-operation was 44.4%. The results of logistic regression analyses showed that the score of HDS-R at admission and the walking/mobility BI score at three weeks post-operation were significant predictors of the one year post-operative decline in ADL. The results of the ROC analyses showed that the cut-off value of the HDS-R score at admission was < 23 points. The posterior probability increased to 62.0%. In contrast, the cut-off value of the walking/mobility BI score was 0 points. The posterior probability increased to 91.0%. CONCLUSION: The ADL decline of the patients who underwent hip fracture surgery at one year after surgery can be predicted at three weeks post-operation.


Assuntos
Atividades Cotidianas , Fraturas do Quadril/reabilitação , Limitação da Mobilidade , Idoso , Idoso de 80 Anos ou mais , Feminino , Fraturas do Quadril/cirurgia , Hospitalização , Humanos , Masculino , Período Pós-Operatório , Estudos Prospectivos , Caminhada
11.
J Pharmacol Exp Ther ; 309(2): 796-803, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-14742740

RESUMO

Pituitary adenylate cyclase-activating polypeptide (PACAP) is an intraislet neuropeptide and shares insulinotropic and insulin-sensitizing properties with glucagon-like peptide-1 (GLP-1); however, the pathophysiological significance of PACAP in diabetes remains largely unknown. To assess this, we crossed our recently developed transgenic mice overexpressing PACAP in pancreatic beta-cells (Tg/+), with lethal yellow agouti (KKA(y)) mice (A(y)/+), a genetic model for obesity-diabetes, and examined the metabolic and morphological phenotypes of F(1) animals. Tg/+ mice with the A(y) allele (Tg/+:A(y)/+) developed maturity-onset obesity and diabetes associated with hyperglycemia, hyperlipidemia, and hyperphagia, similar to those of A(y)/+ mice, but hyperinsulinemia was significantly ameliorated in Tg/+:A(y)/+ mice. Although A(y)/+ mice exhibited a marked increase in islet mass resulting from hyperplasia and hypertrophy, this increase was significantly attenuated in Tg/+:A(y)/+ mice. Size frequency distribution analysis revealed that the very large islets comprising one-fourth of islets of A(y)/+ mice were selectively reduced in Tg/+:A(y)/+ mice. Because functional defects have been demonstrated in the large islets of obese animal models, together these findings suggest that PACAP regulates hyperinsulinemia and the abnormal increase in islet mass that occurs during the diabetic process.


Assuntos
Hiperinsulinismo/prevenção & controle , Ilhotas Pancreáticas/metabolismo , Neuropeptídeos/metabolismo , Animais , Glicemia/metabolismo , Peso Corporal , Ingestão de Alimentos , Feminino , Teste de Tolerância a Glucose , Hiperplasia/prevenção & controle , Insulina/sangue , Ilhotas Pancreáticas/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neuropeptídeos/fisiologia , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase , Triglicerídeos/sangue
12.
Diabetes ; 52(5): 1155-62, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12716746

RESUMO

Pituitary adenylate cyclase-activating polypeptide (PACAP), a member of the vasoactive intestinal peptide/secretin/glucagon family, stimulates insulin secretion from islets in a glucose-dependent manner at femtomolar concentrations. To assess PACAP's pancreatic function in vivo, we generated transgenic mice overexpressing PACAP in the pancreas under the control of human insulin promoter. Northern blot and immunohistochemical analyses showed that PACAP is overexpressed in pancreatic islets, specifically in transgenic mice. Plasma glucose and glucagon levels during a glucose tolerance test were not different between PACAP transgenic mice and nontransgenic littermates. However, plasma insulin levels in transgenic mice were higher after glucose loading. Also, increases of streptozotocin-induced plasma glucose were attenuated in transgenic compared with nontransgenic mice. Notably, an increase in 5-bromo-2-deoxyuridine-positive beta-cells in the streptozotocin-treated transgenic mice was observed but without differences in the staining patterns by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling. Morphometric analysis revealed that total islet mass tends to increase in 12-month-old transgenic mice but showed no difference between 12-week-old transgenic and nontransgenic littermates. This is the first time that PACAP has been observed to play an important role in the proliferation of beta-cells.


Assuntos
Diabetes Mellitus Experimental/prevenção & controle , Insulina/metabolismo , Ilhotas Pancreáticas/fisiologia , Neuropeptídeos/genética , Animais , Apoptose , Northern Blotting , Diabetes Mellitus Experimental/patologia , Humanos , Insulina/genética , Secreção de Insulina , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/patologia , Cinética , Camundongos , Camundongos Transgênicos , Especificidade de Órgãos , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase , Regiões Promotoras Genéticas , RNA Mensageiro/genética , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...