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1.
Small ; 20(23): e2311430, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38444270

RESUMO

Effectively tuning magnetic state by using current is essential for novel spintronic devices. Magnetic van der Waals (vdW) materials have shown superior properties for the applications of magnetic information storage based on the efficient spin torque effect. However, for most of known vdW ferromagnets, the ferromagnetic transition temperatures lower than room temperature strongly impede their applications and the room-temperature vdW spintronic device with low energy consumption is still a long-sought goal. Here, the highly efficient room-temperature nonvolatile magnetic switching is realized by current in a single-material device based on vdW ferromagnet Fe3GaTe2. Moreover, the switching current density and power dissipation are about 300 and 60000 times smaller than conventional spin-orbit-torque devices of magnet/heavy-metal heterostructures. These findings make an important progress on the applications of magnetic vdW materials in the fields of spintronics and magnetic information storage.

2.
Nat Mater ; 22(1): 50-57, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36396963

RESUMO

Layered α-RuCl3 is a promising material to potentially realize the long-sought Kitaev quantum spin liquid with fractionalized excitations. While evidence of this state has been reported under a modest in-plane magnetic field, such behaviour is largely inconsistent with theoretical expectations of spin liquid phases emerging only in out-of-plane fields. These predicted field-induced states have been largely out of reach due to the strong easy-plane anisotropy of bulk crystals, however. We use a combination of tunnelling spectroscopy, magnetotransport, electron diffraction and ab initio calculations to study the layer-dependent magnons, magnetic anisotropy, structure and exchange coupling in atomically thin samples. Due to picoscale distortions, the sign of the average off-diagonal exchange changes in monolayer α-RuCl3, leading to a reversal of spin anisotropy to easy-axis anisotropy, while the Kitaev interaction is concomitantly enhanced. Our work opens the door to the possible exploration of Kitaev physics in the true two-dimensional limit.


Assuntos
Elétrons , Campos Magnéticos , Anisotropia
3.
Am J Nephrol ; : 1-12, 2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39312887

RESUMO

INTRODUCTION: Worsening renal function poses a significant health risk to elderly individuals. This study aimed to construct a simple risk prediction model for new-onset chronic kidney disease (CKD) among elderly populations. METHODS: In this retrospective cohort study, 5,416 elderly residents (aged ≥65 years) who underwent physical examinations as part of the National Basic Public Health Service project at least twice between January 2017 and July 2021 were included. The endpoint was new-onset CKD, defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 during the follow-up period. Predictors of new-onset CKD were selected using multivariable Cox regression and a stepwise approach. A risk prediction model based on the selected predictors was constructed and evaluated using the concordance index (C-index) and area under curve (AUC). External validation was conducted to verify the model's performance. RESULTS: During the median follow-up period of 2.3 years, the incident of new-onset CKD was 20.1% (n = 1,088). Age, female gender, diabetes, elevated triglyceride levels, and baseline eGFR were selected as predictors. The model demonstrated good predictive performance across the cohort, with a C-index of 0.802. The AUCs for 2-year, 3-year, and 4-year predictions were 0.831, 0.829, and 0.839, respectively. External validation confirmed the model's efficacy, with a 2-year AUC of 0.735. CONCLUSION: This study developed a simple yet effective risk prediction model for new-onset CKD among elderly populations. The model facilitates prompt identification of elderly individuals at risk of renal function decline in primary care, enabling timely interventions.

4.
Nano Lett ; 23(24): 11526-11532, 2023 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-38079244

RESUMO

Fe3GaTe2, a recently discovered van der Waals ferromagnet, demonstrates intrinsic ferromagnetism above room temperature, necessitating a comprehensive investigation of the microscopic origins of its high Curie temperature (TC). In this study, we reveal the electronic structure of Fe3GaTe2 in its ferromagnetic ground state using angle-resolved photoemission spectroscopy and density functional theory calculations. Our results establish a consistent correspondence between the measured band structure and theoretical calculations, underscoring the significant contributions of the Heisenberg exchange interaction (Jex) and magnetic anisotropy energy to the development of the high-TC ferromagnetic ordering in Fe3GaTe2. Intriguingly, we observe substantial modifications to these crucial driving factors through doping, which we attribute to alterations in multiple spin-splitting bands near the Fermi level. These findings provide valuable insights into the underlying electronic structure and its correlation with the emergence of high-TC ferromagnetic ordering in Fe3GaTe2.

5.
Pediatr Res ; 93(5): 1258-1266, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-35986150

RESUMO

BACKGROUND: Urinary tract obstruction is associated with impaired renal urinary concentration; even after the release of the obstruction, patients still suffer from polyuria. It has been reported that the decreased expression of aquaporins (AQPs) is associated with postobstructive polyuria, and erythropoietin (EPO) can promote the recovery of decreased AQP2 expression induced by bilateral ureteral obstruction. However, whether EPO can promote the recovery of the expression of AQP1-3 after the release of unilateral ureteral obstruction (UUO) has not yet been reported. AIMS: To investigate the effects of EPO treatment on the expression of renal AQP1-3 after the release of UUO. METHODS: UUO was established in rats by 24-h temporary unilateral obstruction of renal ureters. Three days following EPO treatment, the kidneys were removed to determine the expression levels of AQP1-3, NLRP3, caspase-1, and IL-1ß via semiquantitative immunoblotting and immunohistochemistry. RESULTS: EPO inhibited the expression of NLRP3, caspase-1, and IL-1ß; reduced plasma creatinine and urea; and promoted the recovery of AQP1-3 expression in UUO rats. CONCLUSIONS: EPO treatment prevented the decreased expression of renal AQPs and the development of impaired urinary concentration capacity after the release of UUO, which may partially occur by way of anti-inflammasome effects. IMPACT: EPO treatment could prevent the decreased expression of renal water transporter proteins AQP1-3 and the development of impaired renal functions, which may be associated with its anti-inflammasome effects. EPO regulated the expression of renal water transporter proteins AQP1-3, which could provide the potential for the treatment of postobstructive polyuresis. EPO treatment could be one of the effective methods by participating in multiple dimensions for patients with obstructive nephropathy.


Assuntos
Eritropoetina , Ureter , Obstrução Ureteral , Ratos , Animais , Obstrução Ureteral/complicações , Obstrução Ureteral/tratamento farmacológico , Obstrução Ureteral/metabolismo , Ureter/metabolismo , Aquaporina 2/metabolismo , Poliúria/complicações , Poliúria/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Rim/metabolismo , Eritropoetina/farmacologia , Eritropoetina/metabolismo , Água , Caspases/metabolismo , Caspases/farmacologia
6.
Lipids Health Dis ; 22(1): 209, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38037060

RESUMO

BACKGROUND: Visceral adiposity index (VAI) and lipid accumulation product (LAP) are comprehensive indicators to evaluate visceral fat and determine the metabolic health of individuals. Carotenoids are a group of naturally occurring antioxidants associated with several diseases. The purpose of this investigation was to explore the association between serum carotenoid concentration and VAI or LAP. METHODS: The data were obtained from the National Health and Nutrition Examination Survey between 2001 and 2006. The levels of serum carotenoids were evaluated using high-performance liquid chromatography. Multivariate linear regression models were employed to investigate the relationship between levels of serum carotenoids and VAI or LAP. The potential non-linear relationship was determined using threshold effect analysis and fitted smoothing curves. Stratification analysis was performed to investigate the potential modifying factors. RESULTS: In total, 5,084 participants were included in this population-based investigation. In the multivariate linear regressions, compared to the lowest quartiles of serum carotenoids, the highest quartiles were significantly associated with VAI, and the effect size (ß) and 95% CI was - 0.98 (- 1.34, - 0.62) for α-carotene, - 1.39 (- 1.77, - 1.00) for ß-carotene, - 0.79 (- 1.18, - 0.41) for ß-cryptoxanthin, - 0.68 (- 0.96, - 0.39) for lutein/zeaxanthin, and - 0.88 (- 1.50, - 0.27) for trans-lycopene. Using piece-wise linear regression models, non-linear relationships were found between ß-carotene and trans-lycopene and VAI with an inflection point of 2.44 (log2-transformed, ug/dL) and 3.80 (log2-transformed, ug/dL), respectively. The results indicated that α-carotene, ß-cryptoxanthin, and lutein/zeaxanthin were linearly associated with VAI. An inverse association was also found between serum carotenoids and LAP after complete adjustments. CONCLUSION: This study revealed that several serum carotenoids were associated with VAI or LAP among the general American population. Further large prospective investigations are warranted to support this finding.


Assuntos
Produto da Acumulação Lipídica , beta Caroteno , Humanos , Licopeno , Inquéritos Nutricionais , Estudos Transversais , Luteína , Zeaxantinas , beta-Criptoxantina , Adiposidade , Estudos Prospectivos , Carotenoides
7.
Proc Natl Acad Sci U S A ; 117(40): 24664-24669, 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-32968024

RESUMO

We used a combination of polarized Raman spectroscopy experiment and model magnetism-phonon coupling calculations to study the rich magneto-Raman effect in the two-dimensional (2D) magnet CrI3 We reveal a layered-magnetism-assisted phonon scattering mechanism below the magnetic onset temperature, whose Raman excitation breaks time-reversal symmetry, has an antisymmetric Raman tensor, and follows the magnetic phase transitions across critical magnetic fields, on top of the presence of the conventional phonon scattering with symmetric Raman tensors in N-layer CrI3 We resolve in data and by calculations that the first-order A g phonon of the monolayer splits into an N-fold multiplet in N-layer CrI3 due to the interlayer coupling [Formula: see text] and that the phonons within the multiplet show distinct magnetic field dependence because of their different layered-magnetism-phonon coupling. We further find that such a layered-magnetism-phonon coupled Raman scattering mechanism extends beyond first-order to higher-order multiphonon scattering processes. Our results on the magneto-Raman effect of the first-order phonons in the multiplet and the higher-order multiphonons in N-layer CrI3 demonstrate the rich and strong behavior of emergent magneto-optical effects in 2D magnets and underline the unique opportunities of spin-phonon physics in van der Waals layered magnets.

8.
Entropy (Basel) ; 25(4)2023 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-37190461

RESUMO

In this study, we examined the effect of charging current density on the hydrogen embrittlement (HE) of MEA and the associated HE mechanisms using electron backscattered diffraction (EBSD). Results show that MEA is susceptible to HE, but is stronger than as-rolled and 3D-printed Cantor alloy and stainless steel. The HE susceptibility of MEA decreases with increasing current density. Ductile fracture with transgranular dimples switches to intergranular brittle fracture with clear slip bands in the interior of grains. EBSD results uncovered that hydrogen facilitates localized slips and deformation twins. Hydrogen-enhanced localized plasticity and hydrogen decohesion are the possible HE mechanisms.

9.
Nanotechnology ; 31(38): 385705, 2020 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-32503016

RESUMO

High entropy alloys (HEAs) holding several principal elements in high concentration have unprecedented combination properties. The design of strong and highly ductile HEAs has attracted extensive attention from researchers in the last decade, such as in mechanisms for inducing different types of phase and nano-sized precipitates. Since some HEAs have low stacking fault energy, nanotwins can form during the plastic deformation process or magnetron sputtering, resulting in enhanced mechanical properties due to the existence of twin boundaries. The addition of twin boundaries is implied to be a promising method in engineering HEAs. Understanding how these twin boundaries affect the mechanical properties of nanotwinned HEAs is the key to designing strong and ductile examples. In this study, we performed a large-scale molecular dynamic simulation to investigate the mechanical properties of HEAs with different twin boundary spacings at various temperatures. The results show that the strength of HEAs at all tested temperatures increases with decreasing twin boundary spacing until a lower critical value of 1.83 nm is reached, which is close to the experimental value (2 nm). The strength of the HEAs at all tested temperatures decreases as the twin boundary spacing is decreased further. The dislocation motion transitions at the critical twin boundary spacing. In the sample with a twin boundary spacing bigger than 1.83 nm, Shockley dislocations tend to intersect the twin boundaries and glide in the hardening modes; on the other hand, Shockley dislocations travel along the direction parallel to the twin boundaries in samples with a twin boundary spacing smaller than 1.83 nm, leading to detwinning and softening in the HEAs. The dislocation motion and entanglement at 1 K are respectively slower and stronger than those at 300 K; the grain boundary activity is more obvious at a higher temperature. A mechanistic theoretical model together with a Hall-Petch relationship is then proposed to consider the coupled twin boundary and temperature effect on the deformation of nanotwinned HEAs.

10.
Med Sci Monit ; 26: e924097, 2020 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-32324718

RESUMO

BACKGROUND Studies have shown that bariatric surgery, such as sleeve gastrectomy (SG), has an adverse effect on bone, including decreased bone mineral density (BMD) and bone metabolism. Peripheral 5-hydroxytryptamine (5-HT) has an adverse regulatory effect on bone formation. Here, we assessed changes in bone metabolism and whether 5-HT is involved in the effect of SG on bone metabolism. MATERIAL AND METHODS A rat model of obesity was established using Wistar rats. After successful modeling, rats were randomly assigned to 2 groups - the SG group and the Sham group - with 10 rats in each group. We then performed sleeve gastrectomy or sham operation. Bone metabolic markers and BMD of rats were measured at 2 and 16 weeks after the operation and the level of 5-HT in serum was determined. Rats were killed at 16 weeks after the operation, and bones of the hind limbs were harvested to measure 5-HT by immunofluorescence. RESULTS BMD was decreased and bone metabolism demonstrated a trend of bone destruction in the rats after SG. A significantly increasing trend in the level of serum 5-HT was found, and bone immunofluorescence showed increased expression of 5-HT. CONCLUSIONS BMD was decrease and bone metabolism demonstrated a trend of bone destruction after SG. SG can affect the level of 5-HT in serum or bone tissue and the 5-HT may be involved in the process through which SG affects bone metabolism.


Assuntos
Osso e Ossos/metabolismo , Gastrectomia/efeitos adversos , Obesidade/metabolismo , Animais , Cirurgia Bariátrica/efeitos adversos , Cirurgia Bariátrica/métodos , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/sangue , Gastrectomia/métodos , Masculino , Obesidade/cirurgia , Obesidade Mórbida/metabolismo , Obesidade Mórbida/cirurgia , Ratos , Ratos Wistar , Serotonina/análise , Serotonina/sangue , Redução de Peso
11.
Med Sci Monit ; 26: e927458, 2020 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-32845875

RESUMO

BACKGROUND The mechanism by which sleeve gastrectomy (SG) improves glycometabolism has remained unclear so far. Increasing evidence has demonstrated that bone is a regulator of glucose metabolism, and osteoblast-derived forkhead box O1 (FoxO1) and lipocalin-2 (LCN2) are regulators of energy metabolism. The aim of this study was to investigate whether the FOXO1/LCN2 signaling pathway is involved in the anti-diabetic effect of SG. MATERIAL AND METHODS Insulin resistance was induced in Wistar rats, which were then intraperitoneally injected with streptozotocin to induce a type 2 diabetic state. Levels of fasting blood glucose, serum insulin, HbA1c, and LCN2 were analyzed at corresponding time points after SG and sham surgeries. The expressions of FOXO1, LCN2, and the melanocortin 4 receptor (MC4R) in bone and hypothalamus were detected by immunofluorescence. FOXO1 siRNA was applied to downregulate FOXO1 expression in osteoblasts of rats. The influence of FOXO1 gene on expression of LCN2 was investigated in cultured osteoblasts by western blot and PCR. RESULTS Glucose metabolism in the SG group was significantly improved. The LCN2 expression in bone in the SG group was higher than that in the sham group, whereas FOXO1 expression in the SG group was lower than that in the sham group. The binding rate of LCN2 and MC4R in the hypothalamus was also higher in the SG group compared with that in the sham group. The downregulation of FOXO1 expression in osteoblasts was accompanied by upregulation of LCN2 expression. CONCLUSIONS These results suggest that the FOXO1/LCN2 signaling pathway participates in the anti-diabetic effect of SG.


Assuntos
Gastrectomia/métodos , Glucose/metabolismo , Lipocalina-2/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Animais , Osso e Ossos/metabolismo , Regulação para Baixo , Lipocalina-2/sangue , Masculino , Ratos , Ratos Wistar , Transdução de Sinais , Redução de Peso
12.
J Environ Manage ; 271: 110948, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32778268

RESUMO

Climate change not only intensifies eutrophication and enhances the rainfall, but also elevates the contents of greenhouse gases, which can further increase the intensity and frequency of extreme precipitation events. The effectivity of phytoremediation of urban wastewaters by water hyacinths under an extreme rainfall event (up to 380 mm d-1) was investigated using self-designed fabrications with six flow rates (2-15 m3 d-1) in situ on pilot scale for 30 days. The results suggest that water hyacinths had high N and P removal capacities even under adverse conditions such as low dissolved oxygen concentrations (DO, <1 mg L-1) and high ammonium concentrations (NH4+-N, >7 mg L-1). Specifically, the highest removal yields of N and P were 13.14 ± 0.47 g N·m-2·d-1 and 2.12 ± 0.04 g P·m-2·d-1, respectively. The results indicate that water hyacinths can be used for water treatment to reduce the amounts of NH4+-N, dissolved organic nitrogen (DON) and phosphate (PO43-) even during extreme precipitation events. Moreover, DO increased due to wet deposition, runoff and surface flows during the extreme rainfall event, resulting in shifts between nitrification and denitrification processes which significantly altered nitrogen forms in urban wastewater. Results of this study suggest that water hyacinths could be recommended as a cost-effective and eco-friendly technology for urban wastewater phytoremediation in areas suffering from frequent extreme precipitation events.


Assuntos
Eichhornia , Poluentes Químicos da Água/análise , Biodegradação Ambiental , Nitrogênio/análise , Águas Residuárias
13.
Pediatr Res ; 86(5): 595-602, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31261369

RESUMO

BACKGROUND: Decreased expression of the renal aquaporin (AQP) protein family is associated with hydronephrosis in adult humans and animals. However, the expression of AQPs, especially subtypes AQP1-3, which play a core role in the urinary concentration function, in hydronephrotic human fetuses is not clear. The aim of this study is to investigate the expression of the AQP1-3 in normal and hydronephrotic human fetal kidneys. METHODS: Twenty-one normal and six hydronephrotic kidney (HK) samples were harvested from abortive fetuses. Meanwhile, seven normal adult human kidney samples were collected as positive controls. Quantitative real-time PCR, western blotting, and immunohistochemistry were used to analyze the expression of AQP1-3. RESULTS: Both the protein and messenger mRNA expression levels of AQP1-3 increased with gestational age in the normal fetuses, but the levels were significantly lower than those in the adult tissues and significantly higher than those in the hydronephrotic fetuses at the same gestational age. CONCLUSIONS: The increased expression of AQP1-3 with gestational age in the fetal kidney may indicate maturation of the urinary concentrating ability. The lower expression of AQP1-3 in HKs may reflect a maturation obstacle with regard to urinary concentration in human hydronephrotic fetuses.


Assuntos
Aquaporina 1/metabolismo , Aquaporina 3/metabolismo , Feto/metabolismo , Hidronefrose/metabolismo , Rim/metabolismo , Aquaporina 1/genética , Aquaporina 3/genética , Estudos de Casos e Controles , Humanos , Rim/embriologia , RNA Mensageiro/genética
14.
Biochem Biophys Res Commun ; 506(3): 585-589, 2018 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-30366672

RESUMO

OBJECTIVES: Aquaporin-2 (AQP2) is an important water channel protein that is expressed in the renal collecting duct and plays a key role in urine concentration and body water homeostasis. It has been demonstrated that the urinary excretion of AQP2 correlates strongly with its expression in the kidney in adult humans and rats. However, there have been no studies on the urinary excretion of AQP2 in human fetuses during development. Fetal urine is the main source of the amniotic fluid; we speculate that the level of AQP2 in the amniotic fluid could reflect the expression level of the AQP2 protein in the fetal kidney. The purpose of the present study was to explore the relationship between AQP2 in the amniotic fluid and that in the fetal kidney. METHODS: In the present study, the concentration of the AQP2 protein in human amniotic fluid was measured by Enzyme-linked immunosorbent assay (ELISA) and its expression level in human fetal kidneys were examined by wastern blot and immunohistochemistry. RESULTS: Both the expression level of AQP2 in the fetal kidney (F = 195.9, P < 0.001) and the concentration of AQP2 in the amniotic fluid increased with gestational age (F = 1098, P < 0.001). Moreover, the concentration of AQP2 in the amniotic fluid was positively correlated with its expression level in the fetal kidney (r = 0.872, P < 0.0001). CONCLUSIONS: Our research indicates that AQP2 levels in the amniotic fluid may be used as a marker for AQP2 expression in the fetal kidney.


Assuntos
Líquido Amniótico/metabolismo , Aquaporina 2/metabolismo , Feto/metabolismo , Rim/embriologia , Rim/metabolismo , Adulto , Humanos , Rim/anatomia & histologia , Túbulos Renais Coletores/citologia , Túbulos Renais Coletores/metabolismo
15.
Sensors (Basel) ; 18(6)2018 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-29874825

RESUMO

Since the discovery of the giant magnetoresistive (GMR) effect, GMR sensors have gained much attention in last decades due to their high sensitivity, small size, and low cost. The full Wheatstone-bridge-based GMR sensor is most useful in terms of the application point of view. However, its manufacturing process is usually complex. In this paper, we present an efficient and concise approach to fabricate a full Wheatstone-bridge-based angular GMR sensor by depositing one GMR film stack, utilizing simple patterned processes, and a concise post-annealing procedure based on a special layout. The angular GMR sensor is of good linear performance and achieves a sensitivity of 0.112 mV/V/Oe at the annealing temperature of 260 °C in the magnetic field range from -50 to +50 Oe. This work provides a design and method for GMR-sensor manufacturing that is easy for implementation and suitable for mass production.

16.
Crit Rev Biotechnol ; 37(2): 218-228, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26810214

RESUMO

The objective of this review is to provide a concise summary of literature in the Chinese language since late 1970s and focuses on recent development in global scenarios. This work will replenish the FAO summary of water hyacinth utilization from 1917 to 1979 and review ecological and socioeconomic impacts of the water hyacinth from 1980 to 2010. This review also discusses the debate on whether the growth of the water hyacinth is a problem, a challenge or an opportunity. Literature suggested that integrated technologies and good management may be an effective solution and the perception of water hyacinth could change from that of a notorious aquatic weed to a valuable resource, including its utilization as a biological agent for the application in bioremediation for removing excess nutrients from eutrophic water bodies at low cost. Key aspects on system integration and innovation may focus on low-cost and efficient equipment and the creation of value-added goods from water hyacinth biomass. In the socioeconomic and ecological domain of global development, all the successful and sustainable management inputs for the water hyacinth must generate some sort of social and economic benefit simultaneously, as well as benefiting the ecosystem. Potential challenges exist in linkages between the management of water hyacinth on the large scale to the sustainable development of agriculture based on recycling nutrients, bio-energy production or silage and feed production. Further research and development may focus on more detailed biology of water hyacinth related with its utilization, cost-benefit analysis of middle to large-scale application of the technologies and innovation of the equipment used for harvesting and dehydrating the plant.


Assuntos
Eichhornia , Espécies Introduzidas , Controle de Plantas Daninhas/métodos , Animais , Ecossistema , Eichhornia/anatomia & histologia , Eichhornia/fisiologia , Fitoplâncton , Qualidade da Água
17.
Fish Shellfish Immunol ; 44(2): 674-82, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25839971

RESUMO

Copper nanoparticles (Cu-NPs) are widely used in various industrial and commercial applications, but little is known about their potential hazard in the intestines of marine teleosts. In this study we investigated the effects of Cu-NPs and soluble Cu in the intestines of juvenile Epinephelus coioides. The fish were exposed in triplicate to control, 20 or 100 µg Cu L(-1) as either copper sulphate (CuSO4) or Cu-NPs for 25 days. With an increase in Cu-NPs or CuSO4 dose, the concentration of malonaldehyde in the intestines significantly increased, whereas the activities of total superoxide dismutase and catalase as well as glutathione concentration decreased compared to the control. Statistical analysis of an apoptosis index of intestinal cells showed that general dose-dependent apoptosis was induced by Cu-NPs or CuSO4, with Cu-NPs inducing the significantly higher apoptosis index than CuSOv. Caspase-3 and caspase-9 activities were increased with an increase in Cu-NPs or CuSO4 dose, more so in the Cu-NPs than CuSO4 treatment. With an increase in Cu-NPs or CuSOv dose, succinate dehydrogenase and Na(+)-K(+)-ATPase activity and cytochrome c concentration in mitochondria decreased, accompanied by increased cytochrome c concentration in the cytosol. Concentration of heat shock proteins 70 and 90 in the intestines and expression of corresponding genes were enhanced with an increase in the Cu-NPs or CuSOv dose, but the concentrations and expressions of immunoglobulin M and lysozyme decreased (more in the Cu-NPs than CuSO4 treatment) compared to the control. Expression of interleukin-1beta and tumor necrosis factor-alpha showed a dose-dependent increase with the increased Cu-NPs or CuSO4 dose, with the highest expression found in the Cu-NPs treatment. In conclusion, Cu-NPs had similar toxic effects as CuSOv in the intestines of juvenile E. coioides, but toxicity of Cu-NPs was more severe than that of CuSO4.


Assuntos
Apoptose/efeitos dos fármacos , Sulfato de Cobre/toxicidade , Mucosa Intestinal/metabolismo , Intestinos/imunologia , Nanopartículas Metálicas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Perciformes/imunologia , Análise de Variância , Animais , Apoptose/imunologia , Caspase 3/metabolismo , Caspase 9/metabolismo , Catalase/metabolismo , Primers do DNA/genética , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Glutationa/metabolismo , Proteínas de Choque Térmico/metabolismo , Mitocôndrias/efeitos dos fármacos , Estresse Oxidativo/imunologia , Perciformes/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Superóxido Dismutase/metabolismo
18.
J Environ Sci (China) ; 27: 217-24, 2015 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-25597680

RESUMO

The emission of N2 is important to remove excess N from lakes, ponds, and wetlands. To investigate the gas emission from water, Gao et al. (2013) developed a new method using a bubble trap device to collect gas samples from waters. However, the determination accuracy of sampling volume and gas component concentration was still debatable. In this study, the method was optimized for in situ sampling, accurate volume measurement and direct injection to a gas chromatograph for the analysis of N2 and other gases. By the optimized new method, the recovery rate for N2 was 100.28% on average; the mean coefficient of determination (R(2)) was 0.9997; the limit of detection was 0.02%. We further assessed the effects of the new method, bottle full of water, vs. vacuum bag and vacuum vial methods, on variations of N2 concentration as influenced by sample storage times of 1, 2, 3, 5, and 7 days at constant temperature of 15°C, using indices of averaged relative peak area (%) in comparison with the averaged relative peak area of each method at 0 day. The indices of the bottle full of water method were the lowest (99.5%-108.5%) compared to the indices of vacuum bag and vacuum vial methods (119%-217%). Meanwhile, the gas chromatograph determination of other gas components (O2, CH4, and N2O) was also accurate. The new method was an alternative way to investigate N2 released from various kinds of aquatic ecosystems.


Assuntos
Cromatografia Gasosa , Monitoramento Ambiental/métodos , Nitrogênio/análise , Poluentes Químicos da Água/análise , Gases/análise
19.
Sci Rep ; 14(1): 14697, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38926441

RESUMO

Laser powder bed fusion (LPBF) is an additive manufacturing technology with high practical value. In order to improve the quality of the fabricated parts, process monitoring has become a crucial solution, offering the potential to ensure manufacturing stability and repeatability. However, a cardinal challenge involves discerning a precise correlation between process characteristics and potential defects. This paper elucidates the integration of an off-axis vision monitoring mechanism via a high-speed camera focused on capturing the single-track melting phenomenon. An innovative image processing method was devised to segment the plume and spatters, while Kalman filter was employed for multi-object tracking of the spatters. The features of both the plume and spatters were extracted, and their relationship with molten states was investigated. Finally, the PSO-XGBoost algorithm was utilized to identify five molten states, achieving an accuracy of 92.16%. The novelty of this approach resides in its unique combination of plume characteristics, spatter features, and computationally efficient machine learning models, which collectively address the challenge of limited field of view prevalent in real production scenarios, thereby enhancing process monitoring efficacy. Relative to existing methodologies, the proposed PSO-XGBoost approach offers heightened accuracy, convenience, and appropriateness for the monitoring of the LPBF process. This work provides an effective and novel approach to monitor the LPBF process and evaluate the part fabrication quality for complex and changeable working conditions.

20.
Diabetol Metab Syndr ; 16(1): 51, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38414084

RESUMO

BACKGROUND: Diabetic individuals often encounter various sleep-related challenges. Although the association between sleep duration and atrial fibrillation (AF) have been explored, the association of other sleep traits with the incidence of AF remains unclear. A comprehensive understanding of these traits is essential for a more accurate assessment of sleep conditions in patients with diabetes and the development of novel AF prevention strategies. METHODS: This study involved 23,785 patients with diabetes without any pre-existing cardiovascular disease, drawn from the UK Biobank. Sleep behaviour traits examined encompassed sleep duration, chronotype, insomnia, snoring and daytime sleepiness. Sleep duration was categorised into three groups: low (≤ 5 h), proper (6-8 h) and long (≥ 9 h). We assessed associations using multivariate Cox proportional risk regression models. Furthermore, four poor sleep behaviours were constructed to evaluate their impact on the risk of new-onset AF. RESULTS: Over a mean follow-up period of 166 months, 2221 (9.3%) new cases of AF were identified. Short (hazard ratio (HR), 1.28; 95% confidence interval (CI) 1.10-1.50) and long sleep durations (HR 1.16; 95% CI 1.03-1.32) consistently exhibited an elevated risk of AF compared to optimal sleep duration. Early chronotype, infrequent insomnia and daytime sleepiness were associated with 11% (HR 0.89; 95% CI 0.82-0.97), 15% (HR 0.85; 95% CI 0.77-0.95) and 12% (HR 0.88; 95% CI 0.81-0.96) reduced risk of new-onset AF, respectively. However, no significant association was found between snoring and the incidence of AF (HR 0.99; 95% CI 0.91-1.07). CONCLUSIONS: In diabetic populations, sleep duration, chronotype, insomnia and daytime sleepiness are strongly associated with AF incidence. An optimal sleep duration of 6-8 h presents the lowest AF risk compared to short or long sleep duration. Additionally, poor sleep patterns present a greater risk of new-onset AF in women than in men.

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