Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 133
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Phys Chem Chem Phys ; 26(22): 15868-15876, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38787703

RESUMEN

Lifshitz transition was proposed to explain a change of the topology structure in a Fermi surface induced by continuous lattice deformation without symmetry breaking since 1960. It is well known that the anomalies of the kinetic coefficients (the coefficient of heat conduction and electrical conductivity, viscosity, sound absorption, etc.) are usually closely connected with the Lifshitz transition behavior. 2H-TaS2 is a typical representative to study its anomalies of temperature dependence of heat capacity, resistivity, Hall effect, and magnetic susceptibility. Its geometrical structure of the charge density wave (CDW) phase and layer number dependence of carrier-sign alternation upon cooling in the Hall measurements have not been well understood. The geometrical structure (T-Ts) of the CDW phase was predicted through first principles calculations for bulk and mono-layer 2H-TaS2. Driven by electron-lattice coupling, Ta atoms contract to form a partially gapped CDW phase. The CDW phase has a larger average interlayer separation of S-S atoms in the adjacent two layers compared with the metal phase, which results in a weaker chemical bonding among S-S atoms in the adjacent two layers and then a narrower bandwidth of the energy band. The narrower bandwidth of the energy band leads to a larger density of states (DOS) in the out-of-plane direction above the Fermi level for the CDW phase. As the Fermi level continually drops from the DOS region with a negative slope to that with a positive slope on cooling, the reversal of the p → n type carrier and the pocket-vanishing-type Lifshitz transition occur in the bulk 2H-TaS2. However, the Fermi level slightly drops by 6 meV and happens to be at the positions of pseudo band gaps, so the reduction of in-plane DOS and total DOS is responsible for the always p-type carrier in the mono-layer samples. Our CDW vector of the k-space separation between two saddle points is QSP ≈ 0.62 GK and can provide a theoretical support for the "saddle-point" CDW mechanism proposed by Rice and Scott. Our theoretical explanation gives a new understanding of both Lifshitz transition for symmetry breaking and reversal for the p-n carrier sign in the Hall measurements in various two-dimensional transition metal disulfides.

2.
Phys Chem Chem Phys ; 26(3): 2376-2386, 2024 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-38167696

RESUMEN

In most two-dimensional transition metal chalcogenides, the superconducting phase coexists with the charge density wave (CDW) phase. There exists at least one case, i.e. bulk 2H-NbS2, that does not conform to this picture. Scientists have shown great interest in trying to experimentally find the CDW phase of bulk NbS2 since 1975. Is there any theoretically more stable thermodynamic state than its higher-temperature metal phase, especially in the case of charge injection? Theoretically more stable CDW bulk configurations (TC for 2H-NbS2 and TTs for 2H-NbSe2) with partial pseudo energy gaps were predicted through the harmonic phonon softening theory and first-principles calculations. The ratios of larger to smaller pseudo gaps around K-H segment in the Brillouin zone for CDW phases are basically equal to those of superconductivity phases for bulk 2H-NbX2 (X = S and Se). The CDW phase should coexist with its superconductor state below the critical temperature rather than the metal phase for bulk 2H-NbS2. The presence of CDW phase should be more easily observed experimentally when the injected charge reaches 0.5e/Nb18S36 for bulk 2H-NbS2. Our calculations of density of state (DOS) indicated that, during Nb atoms contracting to form the CDW phases with symmetry breaking in the in-plane direction, dominant conductive carriers are always of p-type for bulk 2H-NbS2 while the alternation of carrier type from p-type to n-type occurs for bulk 2H-NbSe2. The Fermi level continuously drops and then the M-L segment of the out-of-plane energy band emerges from the Fermi surface, which corresponds to the reversal of p-n type sign. Lifshitz transition of pocket-vanishing types occurs in the out-of-plane direction without symmetry breaking during the geometrical structural phase transition for bulk 2H-NbSe2. Our calculations have theoretically addressed the long-standing coexistence issue of CDW and superconducting phases.

3.
Environ Res ; 243: 117708, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-37993044

RESUMEN

The Dongjiang River, a major tributary of the Pearl River system that supplies water to more than 40 million people in Guangdong Province and neighboring regions of China, harbors rich biodiversity, including many endemic and endangered species. However, human activities such as urbanization, agriculture, and industrialization have posed serious threats to its water quality and biodiversity. To assess the status and drivers of phytoplankton diversity, which is a key indicator of aquatic ecosystem health, this study used Environmental DNA (eDNA) metabarcoding combined with machine learning methods to explore spatial variations in the composition and structure of phytoplankton communities along the Dongjiang River, including its estuary. The results showed that phytoplankton diversity exhibited spatial distribution patterns, with higher community structure similarity and lower network complexity in the upstream than in the downstream regions. Environmental selection was the main mechanism shaping phytoplankton community composition, with natural factors driving the dominance of Pyrrophyta, Ochrophyta, and Cryptophyta in the upstream regions and estuaries. In contrast, the downstream regions was influenced by high concentrations of pollutants, resulting in increased abundance of Cryptophyta. The random forest model identified temperature, dissolved oxygen, chlorophyll a, NO2-, and NH4+ as the main factors influencing the primary phytoplankton communities and could be used to predict changes during wet periods. This study provides valuable insights into the factors influencing phytoplankton diversity and community composition in the Dongjiang River, and demonstrates the application value of eDNA metabarcoding technique in large-scale, long-distance river biodiversity monitoring.


Asunto(s)
ADN Ambiental , Fitoplancton , Humanos , Fitoplancton/genética , Ecosistema , Clorofila A , Código de Barras del ADN Taxonómico , Biodiversidad , China , Monitoreo del Ambiente/métodos
4.
J Environ Manage ; 354: 120352, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38367503

RESUMEN

Tidal river networks are affected by the tide and influenced by complex factors related to sediment oxygen demand (SOD). In this study, we used chemical inhibition to measure the oxygen consumption of different types of SOD to explore the specific oxygen consumption mechanism of sediments. Then, we evaluated the diffusion fluxes of the sediment-water interface and factors affecting SOD using diffusive gradients in thin films. Total SOD in the tidal river network area of the Pearl River basin was ∼0.5928 g/m2/day, which was 8.47% higher than that in the non-tidal river network area but lower than that in black and odorous water reported previously. In the tidal river network area, biological SOD was 15.6% higher in summer than in winter, and the difference in total SOD was greatly influenced by human activity. We observed a significant effect of sediment on SOD in winter, whereas there were no significant correlations between sediment and SOD in summer. Different particle-size distributions lead to different organic matter contents, resulting in different biological SOD ratios between seasons. Our study found that seasonal tidal changes can affect ion exchange at the sediment water interface, leading to changes in SOD.These findings will be of great significance for the study of phenomena associated with low dissolved oxygen in tidal river networks and provide directions for future sediment pollution control.


Asunto(s)
Monitoreo del Ambiente , Ríos , Humanos , Monitoreo del Ambiente/métodos , Ríos/química , Sedimentos Geológicos/química , Agua , Oxígeno
5.
Gastroenterol Hepatol ; 47(6): 627-645, 2024.
Artículo en Inglés, Español | MEDLINE | ID: mdl-38307489

RESUMEN

We conducted this study to systematically review and assess the current clinical practice guidelines (CPGs) related to the diagnosis and treatment of Helicobacter pylori (H. pylori) infection. The aim was to evaluate the quality of these included CPGs and provide clinicians with a convenient and comprehensive reference for updating their own CPGs. We searched four databases to identify eligible CPGs focusing on H. pylori diagnosis and treatment recommendations. The results were presented using evidence mappings. Quality and clinical applicability were assessed comprehensively using AGREE-II and AGREE-REX. Statistical tests, specifically Bonferroni tests, were employed to compare the quality between evidence-based guidelines and consensus. A total of 30 eligible CPGs were included, comprising 17 consensuses and 13 guidelines. The quality showed no statistical significance between consensuses and guidelines, mainly within the moderate to low range. Notably, recommendations across CPGs exhibited inconsistency. Nevertheless, concerning diagnosis, the urea breath test emerged as the most frequently recommended method for testing H. pylori. Regarding treatment, bismuth quadruple therapy stood out as the predominantly recommended eradication strategy, with high-dose dual therapy being a newly recommended option. Our findings suggest the need for specific organizations to update their CPGs on H. pylori or refer to recently published CPGs. Specifically, CPGs for pediatric cases require improvement and updating, while a notable absence of CPGs for the elderly was observed. Furthermore, there is a pressing need to improve the overall quality of CPGs related to H. pylori. Regarding recommendations, additional evidence is essential to elucidate the relationship between H. pylori infection and other diseases and refine test indications. Clinicians are encouraged to consider bismuth quadruple or high-dose dual therapy, incorporating locally sensitive antibiotics, as empirical radical therapy. .


Asunto(s)
Infecciones por Helicobacter , Helicobacter pylori , Guías de Práctica Clínica como Asunto , Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/diagnóstico , Humanos , Pruebas Respiratorias , Antibacterianos/uso terapéutico , Bismuto/uso terapéutico , Quimioterapia Combinada
6.
Zhongguo Dang Dai Er Ke Za Zhi ; 26(5): 444-449, 2024 May 15.
Artículo en Zh | MEDLINE | ID: mdl-38802902

RESUMEN

Recombinant human growth hormone (rhGH) is an effective therapeutic drug for improving short stature. Currently, rhGH can be used for various causes of short stature, including growth hormone deficiency, and the expansion of its clinical application has raised concerns about its safety. Based on existing evidence, when rhGH is used in a standardized manner for physiological replacement therapy, its safety profile is favorable. In clinical practice, attention should be focused on short-term safety during rhGH treatment, with the combination of literature evidence and clinical experience. There is still no definitive conclusion on the long-term safety due to insufficient duration of rhGH treatment. This paper reviews the possible adverse events that may occur during rhGH treatment and their risk control measures, aiming to help clinical physicians understand the overall safety of rhGH treatment and improve its clinical standardization.


Asunto(s)
Hormona de Crecimiento Humana , Proteínas Recombinantes , Humanos , Hormona de Crecimiento Humana/efectos adversos , Hormona de Crecimiento Humana/uso terapéutico , Hormona de Crecimiento Humana/administración & dosificación , Proteínas Recombinantes/efectos adversos , Proteínas Recombinantes/uso terapéutico , Proteínas Recombinantes/administración & dosificación
7.
Prev Med ; 172: 107524, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37127121

RESUMEN

With the improvement of people's quality of life, various cardiovascular diseases are the most common diseases. Therefore, the main site of disease atherosclerosis is blood vessels, so we can see that its flow rate has obvious changes. Through the analysis of coronary heart disease, this paper studies the relationship between coronary artery disease and cardiovascular disease, which is helpful to evaluate the risk of disease, and also provides the best prevention and treatment plan to overcome cardiovascular disease. As the material of artificial cartilage repair, nanocomposite hydrogel has excellent application value and attraction, because nanocomposite hydrogel has a structure similar to the extracellular matrix of natural chondrocytes. The patients in the experimental group were treated with nano composite hydrogel stent implantation. The other group of patients used the traditional way to carry out the comparative experiment. In the perfusion data of each ventricular wall in the coronary angiography and anterior wall perfusion group, the percentage of lateral wall in the normal proportion was the highest, 69.2%, 59.3% in the anterior wall, 39.5% in the inferior wall, and 19.7% in the apical value and interval. The percentage of LAD stenosis in anterior wall perfusion was O. The highest percentage in the lateral wall was 69.2%, and the lowest in the septum and apex was 19.7%. Nanocomposite hydrogel stent implantation can effectively treat coronary heart disease. The research shows that it is safe and effective in application.


Asunto(s)
Enfermedades Cardiovasculares , Enfermedad de la Arteria Coronaria , Humanos , Enfermedad de la Arteria Coronaria/cirugía , Nanogeles , Calidad de Vida , Stents , Hidrogeles/uso terapéutico
8.
Artículo en Inglés | MEDLINE | ID: mdl-36708201

RESUMEN

OBJECTIVE: This retrospective analysis was to examine the efficacy and safety of belimumab in lupus nephritis in China. MATERIALS AND METHODS: 25 patients who were regularly followed up every 3 months in our hospital in China were included. All patients were diagnosed as having lupus nephritis and received belimumab to complement standard therapy. The primary outcomes 24-hour proteinuria, complement level, estimated glomerular filtration rate (eGFR), SELENA-SLEDAI scores, prednisone daily dose, and adverse reactions were recorded at 12, 24, 36, and 48 weeks. RESULTS: The SELENA-SLEDAI scores and 24-hour urine protein of the 25 patients decreased visibly from baseline 15.96 ± 3.02, 1.52 ± 1.72 to 9.52 ± 2.66 (p < 0.01), 0.5 ± 0.2 (p < 0.05) at 48 weeks, the eGFR of the 25 patients increased from 76.45 ± 22.2 to 85.48 ± 19.26 (p < 0.01) at 48 weeks, complement levels also showed a trend to increase. One patient experienced renal flare at 48 weeks, and the level of the patient's 24-hour proteinuria had been > 0.7 g at 6 months; this may be a strong predictive factor for further renal response at 12 months. Belimumab added to the standard therapy also improved the hematologic complications caused by systemic lupus erythematosus in 2 patients with a lower glucocorticoid dose. There were no serious adverse events. CONCLUSION: Belimumab may be effective and safe in lupus nephritis even with regard to hematologic complications.

9.
Scand J Gastroenterol ; 57(12): 1509-1516, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35793450

RESUMEN

OBJECTIVE: To determine the risk factors for emergency endoscopic variceal ligation (EVL) failure in acute variceal bleeding (AVB). METHODS: Data from 161 cirrhosis patients with oesophageal variceal bleeding who underwent emergency EVL treatment at the Second Hospital of Hebei Medical University from January 2018 to May 2021 were retrospectively analysed. Enrolled patients were divided into a successful treatment group and a failed treatment group. The variables studied were demographic, clinical, imaging, laboratory, and endoscopic data from the enrolled patients. RESULTS: Of the enrolled patients, 19 patients experienced emergency EVL failure. Of these patients, nine underwent emergency endoscopic treatment again, six patients were treated with a Sengstaken-Blakemore tube for haemostasis and endoscopic treatment, four patients received drug therapy. The presence of portal vein thrombosis (PVT) in the failure group was higher than that in the success group (p < .05). Active bleeding on endoscopy was associated with emergency EVL failure for patients with Child-Pugh class C (p < .05). CONCLUSIONS: Child-Pugh class C with active bleeding on endoscopy or the presence of PVT could increase the risk of emergency EVL failure. The patient's condition should be fully evaluated before emergency endoscopic treatment to reduce the risk of failure.


Asunto(s)
Várices Esofágicas y Gástricas , Trombosis de la Vena , Humanos , Várices Esofágicas y Gástricas/complicaciones , Várices Esofágicas y Gástricas/cirugía , Hemorragia Gastrointestinal/etiología , Hemorragia Gastrointestinal/cirugía , Estudios Retrospectivos , Ligadura , Endoscopía Gastrointestinal/métodos , Insuficiencia del Tratamiento , Factores de Riesgo , Trombosis de la Vena/complicaciones
10.
BMC Public Health ; 22(1): 2345, 2022 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-36517789

RESUMEN

BACKGROUND: Growth chart is a valuable clinical tool to monitor the growth and nutritional status of children. A growth chart widely used in China is based on the merged data sets of national surveys in 2005. We aimed to establish an up-to-date, complete growth curve for urban Chinese children and adolescents with a full range of ages. METHODS: Using data collected in a large-scale, cross-sectional study (Prevalence and Risk factors for Obesity and Diabetes in Youth (PRODY), 2017-2019), we analyzed 201,098 urban children aged 3 to 18 years from 11 provinces, autonomous regions, and municipalities that are geographically representative of China. All participants underwent physical examinations. Sex-specific percentiles of height-for-age and weight-for-age were constructed by Generalized Additive Models for Location Scale and Shape (GAMLSS) model. We also compared the median values of height-for-age or weight-for-age between our growth chart and the established growth reference using Welch-Satterthwaite T-Test. RESULTS: Consistent with the established growth reference, we observed that the P50 percentile of height-for-age reached plateaus at the age of 15 years (172 cm) and 14 years (160 cm) for boys and girls, respectively. In addition, boys aged 10 ~ 14 years and girls aged 10 ~ 12 years exhibited the most dramatic weight difference compared to those of other age groups (19.5 kg and 10.3 kg, respectively). However, our growth chart had higher median values of weight-for-age and height-for-age than the established growth reference with mean increases in weight-for-age of 1.36 kg and 1.17 kg for boys and girls, respectively, and in height-for-age of 2.9 cm and 2.6 cm for boys and girls, respectively. CONCLUSIONS: Our updated growth chart can serve as a reliable reference to assess the growth and nutritional status in urban Chinese children throughout the entire childhood.


Asunto(s)
Estatura , Pueblos del Este de Asia , Adolescente , Masculino , Femenino , Niño , Humanos , Peso Corporal , Estudios Transversales , China/epidemiología , Valores de Referencia
11.
Clin Exp Pharmacol Physiol ; 48(1): 147-156, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32860257

RESUMEN

PURPOSE: Keratin 18 (KRT18) is a cytoskeleton protein that plays a key role in multiple cancers. The present study aims to further investigate the roles of KRT18 in gastric cancer (GC) tissues and cells. METHODS: The KRT18 protein expression levels of GC tissues and cells were detected using immunohistochemistry and western blot. The relationship between KRT18 expression levels and the prognosis of GC patients was further analyzed. To explore this relationship, small interfering RNA (siRNA) was used to inhibit the endogenous expression of KRT18 in GC cells. Furthermore, the effects of KRT18 on the proliferation, invasion, migration, and apoptosis of GC cells were analyzed in vitro. In addition, the role of KRT18 in GC-specific processes was investigated. RESULTS: Keratin 18 expression was shown to be up-regulated in GC tissues and associated with poor prognosis. Following KRT18 silencing with siRNA, the proliferation, invasion, and migration ability of GC cells were significantly inhibited, while the apoptotic process was promoted. Furthermore, the activation of the MAPK signalling pathway was identified as the potential mechanism through which KRT18 influenced GC processes. CONCLUSIONS: Keratin 18 plays a cancer-promoting role and might be a potential therapeutic target in the treatment of GC.

12.
Ecotoxicol Environ Saf ; 213: 112026, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33582411

RESUMEN

Bisphenol A (BPA) is a typical environmental endocrine disruptor that can migrate into organisms through skin contact, breathing, diet and various other approaches. The reproductive toxicity and neurotoxicity of BPA has been confirmed by several toxicological studies. However, the neurotoxicity of BPA is still controversial. In the present study, we used PC12 cells as a model to investigate the mechanism of BPA-induced neuronal apoptosis. BPA exposure reduced cell viability, altered cell morphology and aggravated intracellular Lactate dehydrogenase (LDH) release, intracellular Ca2+ concentration, Reactive oxygen species (ROS) levels, apoptosis and the reduction in the mitochondrial transmembrane potential (ΔΨm). Moreover, the results of the Western blot (WB) and Real-time quantitative polymerase chain reaction (RT-qPCR) assays indicated that the expression levels of Nur77 in the BPA group were down-regulated and accompanied by the downregulation of the NF-κb/Bcl-2 proteins and the upregulation of cleaved-caspase 3, which is a marker of apoptosis. However, these changes were significantly reversed with the upregulation of the Nur77 protein by introducing plasmids carrying the nur77 gene. These results indicated that BPA-induced apoptosis was closely related to Nur77-mediated inhibition of the NF-κb/Bcl-2 pathway.


Asunto(s)
Compuestos de Bencidrilo/toxicidad , Disruptores Endocrinos/toxicidad , Fenoles/toxicidad , Animales , Apoptosis , Supervivencia Celular , Receptores Nucleares Huérfanos , Células PC12 , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Ratas , Especies Reactivas de Oxígeno/metabolismo
13.
Int J Cancer ; 146(1): 236-247, 2020 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-31479522

RESUMEN

Cetuximab and panitumumab bind the human epidermal growth factor receptor (EGFR). Although the chimeric cetuximab (IgG1) triggers antibody-dependent-cellular-cytotoxicity (ADCC) of EGFR positive target cells, panitumumab (a human IgG2) does not. The inability of panitumumab to trigger ADCC reflects the poor binding affinity of human IgG2 Fc for the FcγRIII (CD16) on natural killer (NK) cells. However, both human IgG1 and IgG2 bind the FcγRII (CD32A) to a similar extent. Our study compares the ability of T cells, engineered with a novel low-affinity CD32A131R -chimeric receptor (CR), and those engineered with the low-affinity CD16158F -CR T cells, in eliminating EGFR positive epithelial cancer cells (ECCs) in combination with cetuximab or panitumumab. After T-cell transduction, the percentage of CD32A131R -CR T cells was 74 ± 10%, whereas the percentage of CD16158F -CR T cells was 46 ± 15%. Only CD32A131R -CR T cells bound panitumumab. CD32A131R -CR T cells combined with the mAb 8.26 (anti-CD32) and CD16158F -CR T cells combined with the mAb 3g8 (anti-CD16) eliminated colorectal carcinoma (CRC), HCT116FcγR+ cells, in a reverse ADCC assay in vitro. Crosslinking of CD32A131R -CR on T cells by cetuximab or panitumumab and CD16158F -CR T cells by cetuximab induced elimination of triple negative breast cancer (TNBC) MDA-MB-468 cells, and the secretion of interferon gamma and tumor necrosis factor alpha. Neither cetuximab nor panitumumab induced Fcγ-CR T antitumor activity against Kirsten rat sarcoma (KRAS)-mutated HCT116, nonsmall-cell-lung-cancer, A549 and TNBC, MDA-MB-231 cells. The ADCC of Fcγ-CR T cells was associated with the overexpression of EGFR on ECCs. In conclusion, CD32A131R -CR T cells are efficiently redirected by cetuximab or panitumumab against breast cancer cells overexpressing EGFR.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Cetuximab/administración & dosificación , Neoplasias/tratamiento farmacológico , Panitumumab/administración & dosificación , Receptores de Antígenos de Linfocitos T/metabolismo , Receptores de IgG/metabolismo , Línea Celular Tumoral , Receptores ErbB/metabolismo , Proteínas Ligadas a GPI/metabolismo , Células HEK293 , Humanos , Técnicas In Vitro , Neoplasias/metabolismo , Linfocitos T/metabolismo
14.
Soft Matter ; 16(21): 5009-5019, 2020 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-32436554

RESUMEN

We demonstrated that the formation and solidification of a continuous confined water film played a very important role in changing the elastic modulus of the wet polymer substrate in a nanoindentation process by a coarse-grained molecular dynamics simulation of this process. It was found that as the water content increased, the elastic modulus of the wet polymer substrate showed a non-monotonic change. Relative to the dry polymer substrate, the elastic modulus of the wet polymer first decreased. This is because the appearance of a confined water film caused the force between the polymer substrate and the indenter to change from repulsion to attraction. Subsequently, as the confined water film gradually solidified and then weakened, the elastic modulus of the wet polymer slowly increased and then rapidly increased due to a large number of interstitial water molecules gradually penetrating the polymer substrate. Therefore, it is unreasonable to explain the wet polymer degradation during nanoindentation only from the plasticization and anti-plasticization effects based on the hydrogen bond breaking and formation during stretching. The above-mentioned results will help to more comprehensively understand the degradation mechanism of the polymers' encounter with water, thus promoting further practical applications for polymers.

15.
Ecotoxicol Environ Saf ; 171: 813-822, 2019 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-30660975

RESUMEN

Investigating the occurrence of disinfection by-products (DBPs) and identify the related influencing factors in drinking water is essentially important to control DBPs risk. In this study, 64 tap water samples were collected from 8 counties (or county level cities) in Jinhua Region of Zhejiang Province, China. Results showed that the median (range) of trihalomethane (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), haloketones (HKs) and halonitromethanes (HNMs) were 23.2 (9.1-40.9), 15.3 (5.8-38.6), 2.2 (0.7-7.6), 2.1 (0.2-6.4) and 0.7 (0.2-2.9) µg/L, respectively. HAAs, HANs, HKs and HNMs levels were generally higher in summer than in winter or spring, while for THMs in most counties, higher levels occurred in winter than in summer or spring. Spatially, Yongkang, Yiwu and Dongyang had higher DBPs levels than Pujiang, Pan'an, Lanxi, Wuyi and Jinhua, which was generally consistent with their economy development (GDP). Correlation analysis showed that DBPs occurrence in tap water was significantly related with physicochemical parameters. Principle component analysis further suggested that organic matter (DOC and UVA254) are the major factors influencing the occurrence of THMs, HAAs, HANs and HKs in tap water, while for HNMs, both the organic (DOC and UVA254) and inorganic factors (e.g. Temp, NO2--N, pH, Br- and NH4+-N) played important role in its formation.


Asunto(s)
Desinfectantes/química , Agua Potable/química , Contaminantes Químicos del Agua/química , Acetatos/análisis , Acetonitrilos/análisis , China , Hidrocarburos Halogenados/análisis , Cetonas/análisis , Estaciones del Año , Trihalometanos/análisis
16.
Cardiovasc Diabetol ; 17(1): 90, 2018 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-29907160

RESUMEN

BACKGROUND: Raised hemoglobinA1c (HbA1c) is an indicator of pre-diabetes, which is associated with increased risk of coronary artery disease. However, the detailed morphological characteristics of non-culprit plaques in acute coronary syndrome (ACS) patients remain largely unknown. METHODS: A total of 305 non-culprit plaques from 216 ACS patients were analyzed by intravascular optical coherence tomography. These patients were divided into three groups according to the serum glycosylated hemoglobin level: normal HbA1c (< 5.7%), pre-diabetes with raised HbA1c (5.7-6.4%) and diabetes mellitus (DM). RESULTS: Plaques in patients with raised HbA1c had a longer lipid length (17.0 ± 8.3 mm vs. 13.9 ± 7.2 mm, P = 0.004) and greater lipid index (2775.0 ± 1694.0 mm° vs. 1592.1 ± 981.2 mm°, P = 0.001) than those with normal HbA1c but were similar to DM. The prevalence of calcification in patients with raised HbA1c was significantly higher (38.7% vs. 26.3%, P = 0.048) than normal HbA1c but was similar to DM. The percentage of macrophage infiltration in the DM group was higher than that in the normal HbA1c group (20.5% vs. 7.4%, P = 0.005). CONCLUSIONS: Compared to patients with normal HbA1c, the non-culprit plaques in ACS patients with raised HbA1c had more typical vulnerable features but were similar to DM.


Asunto(s)
Síndrome Coronario Agudo/diagnóstico por imagen , Vasos Coronarios/diagnóstico por imagen , Diabetes Mellitus/sangre , Hemoglobina Glucada/análisis , Placa Aterosclerótica , Estado Prediabético/sangre , Tomografía de Coherencia Óptica , Síndrome Coronario Agudo/sangre , Síndrome Coronario Agudo/patología , Anciano , Biomarcadores/sangre , Angiografía Coronaria , Vasos Coronarios/patología , Diabetes Mellitus/diagnóstico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estado Prediabético/diagnóstico , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Regulación hacia Arriba , Calcificación Vascular/diagnóstico por imagen , Calcificación Vascular/patología
17.
Biomed Eng Online ; 16(1): 53, 2017 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-28449672

RESUMEN

BACKGROUND: The challenge of reconstructing a sparse medical magnetic resonance image based on compressed sensing from undersampled k-space data has been investigated within recent years. As total variation (TV) performs well in preserving edge, one type of approach considers TV-regularization as a sparse structure to solve a convex optimization problem. Nevertheless, this convex optimization problem is both nonlinear and nonsmooth, and thus difficult to handle, especially for a large-scale problem. Therefore, it is essential to develop efficient algorithms to solve a very broad class of TV-regularized problems. METHODS: In this paper, we propose an efficient algorithm referred to as the fast linearized preconditioned alternating direction method of multipliers (FLPADMM), to solve an augmented TV-regularized model that adds a quadratic term to enforce image smoothness. Because of the separable structure of this model, FLPADMM decomposes the convex problem into two subproblems. Each subproblem can be alternatively minimized by augmented Lagrangian function. Furthermore, a linearized strategy and multistep weighted scheme can be easily combined for more effective image recovery. RESULTS: The method of the present study showed improved accuracy and efficiency, in comparison to other methods. Furthermore, the experiments conducted on in vivo data showed that our algorithm achieved a higher signal-to-noise ratio (SNR), lower relative error (Rel.Err), and better structural similarity (SSIM) index in comparison to other state-of-the-art algorithms. CONCLUSIONS: Extensive experiments demonstrate that the proposed algorithm exhibits superior performance in accuracy and efficiency than conventional compressed sensing MRI algorithms.


Asunto(s)
Algoritmos , Artefactos , Compresión de Datos/métodos , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Modelos Lineales , Imagen por Resonancia Magnética/métodos , Humanos , Imagen por Resonancia Magnética/instrumentación , Fantasmas de Imagen , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
18.
PLoS Genet ; 9(5): e1003517, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23696751

RESUMEN

Clathrin and the multi-subunit adaptor protein complex AP2 are central players in clathrin-mediated endocytosis by which the cell selectively internalizes surface materials. Here, we report the essential role of clathrin and AP2 in phagocytosis of apoptotic cells. In Caenorhabditis elegans, depletion of the clathrin heavy chain CHC-1 and individual components of AP2 led to a significant accumulation of germ cell corpses, which resulted from defects in both cell corpse engulfment and phagosome maturation required for corpse removal. CHC-1 and AP2 components associate with phagosomes in an inter-dependent manner. Importantly, we found that the phagocytic receptor CED-1 interacts with the α subunit of AP2, while the CED-6/Gulp adaptor forms a complex with both CHC-1 and the AP2 complex, which likely mediates the rearrangement of the actin cytoskeleton required for cell corpse engulfment triggered by the CED-1 signaling pathway. In addition, CHC-1 and AP2 promote the phagosomal association of LST-4/Snx9/18/33 and DYN-1/dynamin by forming a complex with them, thereby facilitating the maturation of phagosomes necessary for corpse degradation. These findings reveal a non-classical role of clathrin and AP2 and establish them as indispensable regulators in phagocytic receptor-mediated apoptotic cell clearance.


Asunto(s)
Complejo 2 de Proteína Adaptadora/metabolismo , Caenorhabditis elegans/metabolismo , Clatrina/metabolismo , Fagocitosis/genética , Complejo 2 de Proteína Adaptadora/genética , Animales , Apoptosis/genética , Proteínas Reguladoras de la Apoptosis , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Clatrina/genética , Cadenas Pesadas de Clatrina/metabolismo , Endocitosis , Células Germinativas/patología , Proteínas de la Membrana/metabolismo , Fagocitosis/fisiología , Fagosomas/genética , Fagosomas/metabolismo , Fosfoproteínas/metabolismo , Transducción de Señal
19.
J Chem Theory Comput ; 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-39020520

RESUMEN

The success of machine learning in predicting material properties is largely dependent on the design of the model. However, the current designs of deep learning models in materials science have the following prominent problems. First, the model design lacks a rational guidance strategy and heavily relies on a large amount of trial and error. Second, numerous deep learning models are utilized across various fields, each with its own advantages and disadvantages. Therefore, it is important to incorporate a fusion strategy to fully leverage them and further expand the design strategies of the models. To address these problems, we analyze that the main reason is the lack of a new feedback method rich in physical insights. In this study, we developed a feedback method called the Chemical Environment Clustering Vector (CECV) of compounds at different thresholds, which is rich in physical insights. Based on CECV, we rationally designed the Long Short-Term Memory and Gated Recurrent Unit fused with Deep Convolutional Neural Network (L-G-DCNN) to explore the field of structure-agnostic material property predictions. L-G-DCNN accurately captures the interactions between elements in compounds, enabling more accurate and efficient predictions of the material properties. Our results demonstrate that the performance of the L-G-DCNN surpasses the current state-of-the-art structure-agnostic models across 28 benchmark data sets, exhibiting superior sample efficiency and faster convergence speed. By employing different visualization methods, we demonstrate that the fusion strategy based on CECV significantly enhances the comprehension of the L-G-DCNN model design and provides a fresh perspective for researchers in the field of materials informatics.

20.
Magn Reson Imaging ; 111: 246-255, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38663831

RESUMEN

Magnetic resonance imaging produces detailed anatomical and physiological images of the human body that can be used in the clinical diagnosis and treatment of diseases. However, MRI suffers its comparatively longer acquisition time than other imaging methods and is thus vulnerable to motion artifacts, which ultimately lead to likely failed or even wrong diagnosis. In order to perform faster reconstruction, deep learning-based methods along with traditional strategies such as parallel imaging and compressed sensing come into play in recent years in this field. Meanwhile, in order to better analyze the diseases, it is also often necessary to acquire images in the same region of interest under different modalities, which yield images with different contrast levels. However, most of these aforementioned methods tend to use single-modal images for reconstruction, neglecting the correlation and redundancy information embedded in MR images acquired with different modalities. While there are works on multi-modal reconstruction, the information is yet to be efficiently explored. In this paper, we propose an end-to-end neural network called MLMFNet, which helps the reconstruction of the target modality by using information from the auxiliary modality across feature channels and layers. Specifically, this is highlighted by three components: (I) An encoder based on UNet with a single-stream strategy that fuses auxiliary and target modalities; (II) a decoder that tends to multi-level features from all layers of the encoder, and (III) a channel attention module. Quantitative and qualitative analyses are performed on a public brain dataset and knee brain dataset, which show that the proposed method achieves satisfying results in MRI reconstruction within the multi-modal context, and also demonstrate its effectiveness and potential to be used in clinical practice.


Asunto(s)
Algoritmos , Encéfalo , Aprendizaje Profundo , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Humanos , Imagen por Resonancia Magnética/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Encéfalo/diagnóstico por imagen , Redes Neurales de la Computación , Imagen Multimodal/métodos , Rodilla/diagnóstico por imagen
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA