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1.
Nano Lett ; 22(23): 9470-9476, 2022 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-36455210

RESUMEN

Materials for studying biological interactions and for alternative energy applications are continuously under development. Semiconductor quantum dots are a major part of this landscape due to their tunable optoelectronic properties. Size-dependent quantum confinement effects have been utilized to create materials with tunable bandgaps and Auger recombination rates. Other mechanisms of electronic structural control are under investigation as not all of a material's characteristics are affected by quantum confinement. Demonstrated here is a new structure-property concept that imparts the ability to spatially localize electrons or holes within a core/shell heterostructure by tuning the charge carrier's kinetic energy on a parabolic potential energy surface. This charge carrier separation results in extended radiative lifetimes and in continuous emission at the single-nanoparticle level. These properties enable new applications for optics, facilitate novel approaches such as time-gated single-particle imaging, and create inroads for the development of other new advanced materials.


Asunto(s)
Nanopartículas , Puntos Cuánticos , Puntos Cuánticos/química , Nanopartículas/química , Semiconductores , Electrones , Electrónica
2.
BMC Oral Health ; 23(1): 661, 2023 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-37705022

RESUMEN

BACKGROUND: This study is to evaluate and compare the improvement of upper airway morphology and hyoid bone position in children with Class II mandibular retrusion treated with Invisalign mandibular advancement (MA) and Twin-Block (TB) appliances, utilizing cone beam computed tomography (CBCT). METHODS: 32 children aged between 8 and 11.5 years old were included in this study, with an average age of 10.2 years old. These children were divided into two groups, MA and TB, with 16 children in each group. Changes in upper airway morphology and hyoid bone position before and after treatment were analyzed using CBCT. RESULTS: (1) Changes in upper airway before and after treatment: the oropharynx volume (Or-V), the oropharynx minimum cross-sectional area (Or-mCSA), the hypopharynx volume (Hy-V), and the hypopharynx minimum cross-sectional area (Hy-mCSA) in both the MA and TB groups increased after treatment, and the differences were statistically significant (P < 0.05) compared to pre-treatment status. (2) Changes in hyoid bone position before and after treatment: The distances between H point and third cervical vertebra (H-C3), H point and pogonion (H-RGN), H point and mandibular plane (H-MP), H point and Frankfort horizontal plane (H-FH), H and S point (H-S), and H point and palatal plane (H-PP) in both the MA and TB groups increased after treatment, and the differences were statistically significant (P < 0.05). CONCLUSION: Both MA and TB appliances effectively improved the structural narrowness of the upper airway and reduced respiratory resistance, thus improving breath quality. However, MA showed more effectiveness in improving the narrowest part of the hypopharynx compared to TB. Both appliances also promoted anterior downward movement of the hyoid bone, which opens the upper airway of the oropharynx and hypopharynx and helps the upper airway morphology return to normal range.


Asunto(s)
Avance Mandibular , Aparatos Ortodóncicos Removibles , Niño , Humanos , Estudios Retrospectivos , Hueso Hioides/diagnóstico por imagen , Nariz
3.
Phys Chem Chem Phys ; 25(1): 471-477, 2022 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-36477113

RESUMEN

We performed QM/MM simulations to investigate excess-electron attachment to four aqueous DNA nucleotide anions (dRT-). The negative QM/MM vertical electron affinities (-0.86 to -0.59 eV) reveal that aqueous dRT- anions improbably capture the excess electron near 0 eV. Comparing with the calculations in the gas phase and without the background charges, it can be found that first-shell water molecules have a larger contribution to the promotion of the ability of the excess-electron capture and the bulk-water polarization has a small effect on vertical electron affinities. The phosphate group hampers the attachment of the very low-energy excess electron to aqueous dRT-. The large adiabatic electron affinities (1.45-1.96 eV) and vertical detachment energies (1.92-2.44 eV) reveal that stable dRT2- dianions could be formed after dRT- anions catch the higher-energy excess electron (>0.59 eV). We computed the energy changes in the dRT2- structural relaxations. The QM-region conformational changes cause small energy alterations (-0.28 to 0.35 eV). The QM/MM energy decreases are 2.31-2.73 eV which mainly come from QM computations (3.49-4.00 eV) embedded in the background charges. The analysis of excess-electron distributions indicates that the polarization of bulk water and structural relaxations of dianions induce the excess-electron redistributions in the QM region and produce large QM-energy decreases. The MM energy changes are -1.27 to -1.11 eV for four aqueous dianions. The negative values demonstrate that the energy of the MM region would increase in dRT2- structural relaxations. In contrast with the values of the polarized QM computations, about 30% of the energy released by the QM region is transferred to bulk water in the MM region. The large energy dissipation probably suppresses DNA damage by the low-energy electron.


Asunto(s)
Nucleótidos , Agua , Agua/química , Electrones , ADN/química , Transferencia de Energía
4.
Colorectal Dis ; 23(2): 424-433, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33191594

RESUMEN

AIM: The aim was to evaluate the physiological variation in rectoanal inhibitory reflex (RAIR) after laparoscopic intersphincteric resection (Lap-ISR) for ultralow rectal cancer. METHOD: This was a retrospective study that included 56 patients who underwent Lap-ISR from a prospectively collected database. The RAIR was examined preoperatively and up to 12 months after ileostomy closure. The primary outcome included physiological variation in RAIR and its difference between partial, subtotal and total ISR. The secondary outcome was its correlation with functional outcome. RESULTS: The reflex was present in 95% (53/56) of patients preoperatively, in 36% (20/56) before ileostomy closure, in 48% (27/56) at 3-6 months and in 61% (34/56) at 12 months after ileostomy closure. The elicited volume of RAIR was significantly increased at 12 months after ileostomy closure than at baseline (P = 0.005), but its duration and amplitude did not differ significantly. There was no significant difference in the reflex recovery between the ISR groups (partial vs. subtotal vs. total: 65% vs. 63% vs. 44%, P = 0.61). At 12 months after ileostomy closure, the RAIR-present group had favourable functional results and patient satisfaction (P < 0.05). Major faecal incontinence was found in 82% of patients in the RAIR-absent group. CONCLUSION: The RAIR is abolished in the majority of patients after Lap-ISR, but a time-dependent recovery could be observed in more than half of the patients. The reflex recovery is not influenced by the resection grade of the internal sphincter. However, persistent loss of the RAIR correlates with worse continence.


Asunto(s)
Laparoscopía , Neoplasias del Recto , Canal Anal/cirugía , Humanos , Neoplasias del Recto/cirugía , Reflejo , Estudios Retrospectivos
5.
Biophys J ; 118(10): 2458-2469, 2020 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-32359407

RESUMEN

Many biophysical problems involve molecular and nanoscale targets moving next to a curvilinear track, e.g., a cytosolic cargo transported by motor proteins moving along a microtubule. For this type of problem, fluorescence imaging is usually the primary tool of choice. There is, however, an ∼20-fold mismatch between target-localization precision and track-imaging resolution such that questions requiring high-fidelity definition of the target's track remain inaccessible. On the other hand, if the contextual image of the tracks can be refined to a level comparable to that of the target, many intuitive yet mechanistically important issues can begin to be addressed. This work demonstrates that it is possible to statistically infer, to subpixel precision, curvilinear features in a low signal/noise image. This is achieved by a framework that consists of three stages: the Hessian-based feature enhancement, the subimage feature sampling and registration, and the statistical learning of the underlying curvilinear structure using a new, to our knowledge, method developed here for inferring the principal curves. In each stage, the descriptive prior information that the features come from curvilinear elements is explicitly taken into account. It is fully automated without user supervision, which is distinctly different from approaches that require user seeding or well-defined training data sets. Computer simulations of realistic images are used to investigate the performance of the framework and its implementation. The characterization results suggest that curvilinear features are refined to the same order of precision as that of the target and that the bootstrap confidence intervals from the analysis allow an estimate for the statistical bounds of the simulated "true" curve. Also shown are analyses of experimental images from three different microscopy modalities: two-photon laser-scanning microscopy, epifluorescence microscopy, and total internal reflection fluorescence microscopy. The practical application of this prior-apprised unsupervised learning framework as well as its potential outlook are discussed.


Asunto(s)
Algoritmos , Procesamiento de Imagen Asistido por Computador , Simulación por Computador , Aprendizaje Automático no Supervisado
6.
Biophys J ; 115(2): 217-229, 2018 07 17.
Artículo en Inglés | MEDLINE | ID: mdl-29241585

RESUMEN

The position-time trajectory of a biological subject moving in a complex environment contains rich information about how it interacts with the local setting. Whether the subject be an animal or an intracellular endosomal vesicle, the two primary modes of biological locomotion are directional movement and random walk, respectively characterized by velocity and diffusion coefficient. This contribution introduces a method to quantitatively divide a single-particle trajectory into segments that exhibit changes in the diffusion coefficient, velocity, or both. With the determination of these two physical parameters given by the maximum likelihood estimators, the relative precisions are given as explicit functions of the number of data points and total trajectory time. The method is based on rigorous statistical tests and does not require any presumed kinetics scheme. Results of extensive characterizations, extensions to 2D and 3D trajectories, and applications to common scenarios are also discussed.


Asunto(s)
Difusión , Cinética , Funciones de Verosimilitud , Movimiento (Física)
7.
Int J Colorectal Dis ; 32(4): 587-590, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27878621

RESUMEN

PURPOSE: The purpose of this study is to compare the clinical and functional outcomes of three types of hand-sewn colo-anal anastomosis (CAA) after laparoscopic intersphincteric resection (Lap-ISR) for patients with ultralow rectal cancer. METHODS: A total of 79 consecutive patients treated by Lap-ISR for low-lying rectal cancer in an academic medical center from June 2011 to February 2016. According to the distal tumor margin and individualized anal length, the patients underwent three types of hand-sewn CAA including partial-ISR, subtotal-ISR, and total-ISR. RESULTS: Of the 79 patients, 35.4% required partial-ISR, 43% adopted subtotal-ISR, and 21.5% underwent total-ISR. R0 resection was achieved in 78 patients (98.7%). In addition to distal resection margin, there were no significant differences in clinicopathological parameters and postoperative complications between the three groups. The type of hand-sewn CAA did not influence the 3-year disease-free survival (DFS) or local relapse-free survival (LFS). At 24-months follow-up, in spite of higher incontinence scores in total-ISR group, there were not statistically significant differences in functional outcomes including Wexner score or Kirwan grade between the groups. Nevertheless, patients with chronic anastomotic stricture showed worse anal function than those without the complication. CONCLUSION: The type of hand-sewn CAA after Lap-ISR may not influence oncological and functional outcomes, but chronic stricture deteriorates continence status.


Asunto(s)
Canal Anal/fisiopatología , Canal Anal/cirugía , Colon/cirugía , Laparoscopía , Neoplasias del Recto/fisiopatología , Neoplasias del Recto/cirugía , Adulto , Anciano , Canal Anal/patología , Anastomosis Quirúrgica , Colon/patología , Femenino , Humanos , Laparoscopía/efectos adversos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Neoplasias del Recto/patología , Resultado del Tratamiento
8.
J Chem Phys ; 145(12): 124305, 2016 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-27782672

RESUMEN

The quantum dynamics calculations of the H + HS (v = 0, j = 0) reaction on the 3A' and 3A″ potential energy surfaces (PESs) are performed using the reactant coordinate based time-dependent wave packet method. State-averaged and state-resolved results for both channels of the title reaction are presented in the 0.02-1.0 eV collision energy range and compared with those carried out with quasi-classical trajectory (QCT) method. Total integral cross sections (ICSs) for both channels are in excellent agreement with previous quantum mechanical (QM)-Coriolis coupling results while poorly agree with the QCT ICSs of the exchange channel, particularly near the threshold energy region. The product rotational distributions show that for the abstraction channel, the agreement between our QM and the QCT results improves with increasing collision energy. For the exchange channel, our calculations predict colder rotational distributions as compared to those obtained by QCT calculations. Although the QM total differential cross sections (DCSs) are in qualitatively good agreement with the QCT results, the two sets of the state-to-state DCSs with several peaks exhibit great divergences. The origin of the divergences are traced by analyzing the QM DCS for the H + HS (v = 0, j = 0) → H2 (v' = 0, j' = 0) + S reaction on the 3A″ PES at Ec = 1.0 eV. It is discovered that several groups of J partial waves are involved in the reaction and the shape of the DCS is greatly altered by quantum interferences between them.

9.
Drug Dev Ind Pharm ; 42(11): 1792-9, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27042965

RESUMEN

LLC-0601(S,S) and LLC-0601(R,R) are two novel synthesized isomerism platinum compounds both with encouraging anticancer activity. However, the previous study showed that toxicity of LLC-0601(R,R) was much higher than that of LLC-0601(S,S) with higher body weight loss and mortality rate of tested rats. This paper is focused on the comparison of the two compounds with their pharmacokinetic (PK) profiles in rats and tissue distribution in mice after intravenous administration. The atomic absorption spectrometry (AAS) method was successfully developed and applied for the determination of platinum in plasma and tissues. The results showed that main PK parameters such as half-life, AUC and MRT of the two compounds had no significant difference after intravenous administration to rats (p  > 0.05). The tissue distribution after intravenous administration to mice showed that the concentration of LLC-0601(R,R) in heart at 0.083 h was higher than that of LLC-0601(S,S) (p < 0.05) and it was the same case for AUC5min-4 h (p < 0.05). Different distribution of the two compounds in heart was possibly the main reason of different toxicity and more in-depth research on the metabolites and other mechanism are needed to investigate the toxicity.


Asunto(s)
Antineoplásicos/farmacocinética , Compuestos Organoplatinos/farmacocinética , Compuestos de Platino/farmacocinética , Animales , Antineoplásicos/química , Isomerismo , Ratones , Compuestos Organoplatinos/química , Compuestos de Platino/química , Ratas , Distribución Tisular
10.
J Biol Chem ; 289(22): 15867-79, 2014 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-24737327

RESUMEN

The serine-histidine-aspartate triad is well known for its covalent, nucleophilic catalysis in a diverse array of enzymatic transformations. Here we show that its nucleophilicity is shielded and its catalytic role is limited to being a specific general base by an open-closed conformational change in the catalysis of (1R,6R)-2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate synthase (or MenH), a typical α/ß-hydrolase fold enzyme in the vitamin K biosynthetic pathway. This enzyme is found to adopt an open conformation without a functional triad in its ligand-free form and a closed conformation with a fully functional catalytic triad in the presence of its reaction product. The open-to-closed conformational transition involves movement of half of the α-helical cap domain, which causes extensive structural changes in the α/ß-domain and forces the side chain of the triad histidine to adopt an energetically disfavored gauche conformation to form the functional triad. NMR analysis shows that the inactive open conformation without a triad prevails in ligand-free solution and is converted to the closed conformation with a properly formed triad by the reaction product. Mutation of the residues crucial to this open-closed transition either greatly decreases or completely eliminates the enzyme activity, supporting an important catalytic role for the structural change. These findings suggest that the open-closed conformational change tightly couples formation of the catalytic triad to substrate binding to enhance the substrate specificities and simultaneously shield the nucleophilicity of the triad, thus allowing it to expand its catalytic power beyond the nucleophilic catalysis.


Asunto(s)
Escherichia coli/enzimología , Oxo-Ácido-Liasas/química , Oxo-Ácido-Liasas/metabolismo , Ácido Aspártico/metabolismo , Catálisis , Cristalografía por Rayos X , Activación Enzimática/fisiología , Histidina/metabolismo , Enlace de Hidrógeno , Mutagénesis Sitio-Dirigida , Oxo-Ácido-Liasas/genética , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Serina/metabolismo , Relación Estructura-Actividad , Vitamina K/biosíntesis
11.
J Am Chem Soc ; 137(2): 580-3, 2015 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-25562211

RESUMEN

The seemingly inevitable protein corona appears to be an insurmountable obstacle to wider application of functional nanomaterials in biotechnology. The accumulation of serum proteins can block targeting functionalities and alter the in vivo fate of these nanomaterials. Here we demonstrate a method to generate non-stick, robustly passivated functional nanoparticles (NPs) using a tailored silica coating. We apply agarose gel electrophoresis to sensitively evaluate protein binding to NPs with different surface chemistry. Using gel banding and retardation as a read-out for protein adsorption, we optimize the surface chemistry to yield a mixed charge surface which displays remarkable binding resistance to a wide range of serum proteins and nucleic acids. The hard silica shell also protects the functional NP core in harsh environments (down to pH 1) while still showing the ability to be targeted for cellular uptake with little or no non-specific binding.


Asunto(s)
ADN/química , Nanopartículas/química , Proteínas/química , Dióxido de Silicio/química , Animales , Geles , Concentración de Iones de Hidrógeno , Ratones , Células 3T3 NIH , Puntos Cuánticos/química
12.
Mol Cell Biochem ; 409(1-2): 113-22, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26188800

RESUMEN

Many recent studies have suggested that bergapten (BP), a class of native compound with numerous biological activities such as anti-resorptive properties, may exert protective effects against postmenopausal bone loss. However, it remains unknown whether BP regulates or improves the osteogenic function of bone marrow stromal cells (BMSCs) in the treatment and prevention of osteoporosis. In our study, BMSCs were cultured in osteogenic induction medium with the addition of BP for 2 weeks and an ovariectomized mouse model of osteoporosis was used to investigate the anti-resorptive effect of BP by gavage administration for 3 months. The concentrations of BP used were 0.1, 1, and 10 µmol/L in vitro and the gavage dose was 20 mg/kg/d. The result of our study indicated that BP promotes the expression of alkaline phosphatase (ALP) by BMSCs in vitro in a dose-dependent manner, as revealed by ALP staining. Runt-related transcription factor 2 and osteocalcin were up-regulated both in vitro and vivo, while osterix and collagen Iα1, assessed by immunofluorescence and immunohistochemistry, were correspondingly raised in the presence of BP in BMSCs in vitro. In addition, a protective effect of BP against ovariectomy-induced bone loss was found by distal femur micro-CT scanning, with improvements of bone metabolism parameters such as bone mineral density, trabecular number, and trabecular separation. Furthermore, WNT/ß-catenin signaling was activated in the presence of BP in BMSCs in osteogenic culture. Finally, BP promoted differentiation of BMSCs into osteoblasts by up-regulation of the WNT/ß-catenin pathway.


Asunto(s)
Células Madre Mesenquimatosas/citología , Metoxaleno/análogos & derivados , Osteoblastos/citología , Osteogénesis/efectos de los fármacos , Fármacos Fotosensibilizantes/farmacología , Vía de Señalización Wnt/efectos de los fármacos , 5-Metoxipsoraleno , Fosfatasa Alcalina/biosíntesis , Animales , Células de la Médula Ósea/citología , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Colágeno Tipo I/biosíntesis , Subunidad alfa 1 del Factor de Unión al Sitio Principal/biosíntesis , Femenino , Metoxaleno/farmacología , Ratones , Ratones Endogámicos C57BL , Osteocalcina/biosíntesis , Osteoporosis/patología , Factor de Transcripción Sp7 , Factores de Transcripción/biosíntesis , Proteínas Wnt/metabolismo , beta Catenina/metabolismo
13.
J Colloid Interface Sci ; 657: 880-892, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38091911

RESUMEN

Covalent post-synthetic modification of metal-organic frameworks (MOFs) represents an underexplored but promising avenue for allowing the addition of specific fluorescent recognition elements to produce the novel MOF-based sensory materials with multiple-analyte detection capability. Here, an excited-state proton transfer (ESPT) active sensor 2D-Zn-NS-P was designed and constructed by covalent post-synthetic incorporation of the excited-state tautomeric 2-hydroxypyridine moiety into the ultrasonically exfoliated amino-tagged 2D Zn-MOF nanosheets (2D-Zn-NS). The water-mediated ESPT process facilitates the highly accessible active sites incorporated on the surface of 2D-Zn-NS-P to specifically respond to the presence of water in common organic solvents via fluorescence turn-on behavior, and accurate quantification of trace amount of water in acetonitrile, acetone and ethanol was established using the as-synthesized nanosheet sensor with the detection sensitivity (<0.01% v/v) superior to the conventional Karl Fischer titration. Upon exposure to Fe3+ or Cr2O72-, the intense blue emission of the aqueous colloidal dispersion of 2D-Zn-NS-P was selectively quenched even in the coexistence of common inorganic interferents. The prohibition of the water-mediated ESPT process and local emission, induced by the coordination of ESPT fluorophore with Fe3+ or by Cr2O72- competitively absorbs the excitation energy, was proposed to responsible for the fluorescence turn-off sensing of the respective analytes. The present study offers the attractive prospect to develop the ESPT-based fluorescent MOF nanosheets by covalent post-synthetic modification strategy as multi-functional sensors for detection of target analytes.

14.
Sci Total Environ ; 904: 166862, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37689193

RESUMEN

High­arsenic (As) sinter deposited from geothermal water is a potentially overlooked hazardous matrix and there remain substantial gaps in our comprehension of the stability of As sequestered within it. In this study, qualitative and quantitative analysis of the mineralogy of As-bearing sinter was conducted by Mineral Liberation Analyzer (MLA) in geothermal areas of the Tibetan Plateau to reveal the geochemical stability of As. Our results indicated that the contents of As in sinter were 3 orders of magnitude higher than the local soil. The dominant host minerals of As were calcite (40.9 %), thenardite (22.5 %), calcium silicate (13.0 %), and halite (8.1 %). Additionally, it was found that a relatively higher As bioavailability was extracted by ethylene diamine tetraacetic acid (EDTA), with a leaching rate of 41.2 %. Notably, the X-ray diffraction (XRD) showed that the thenardite and halite were decomposed after the leaching. The combination of mineralogy and geochemistry data suggested that calcite and calcium silicate were a crucial mechanism for As retention in sinter, while the dissolution of saline minerals (e.g., thenardite, halite, and calcium chloride) served as the primary sources for As release. This finding unveils the potential risks and mechanisms associated with high-As sinter, providing scientific guidance for risk management of sinter.

15.
Environ Sci Pollut Res Int ; 30(58): 122230-122244, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37966647

RESUMEN

The seasonal variations of shallow groundwater arsenic have been widely documented. To gain insight into the monthly variations and mechanisms behind high groundwater arsenic and arsenic exposure risk in different climate scenarios, the monthly probability of high groundwater arsenic in Hetao Basin was simulated through random forest model. The model was based on arsenic concentrations obtained from 566 groundwater sample sites, and the variables considered included soil properties, climate, topography, and landform parameters. The results revealed that spatial patterns of high groundwater arsenic showed some fluctuations among months under different future climate scenarios. The probability of high total arsenic and trivalent arsenic was found to be elevated at the start of the rainy season, only to rapidly decrease with increasing precipitation and temperature. The probability then increased again after the rainy season. The areas with an increased probability of high total arsenic and trivalent arsenic and arsenic exposure risk under SSP126 were typically found in the high-arsenic areas of 2019, while those with decreased probabilities were observed in low-arsenic areas. Under SSP585, which involves a significant increase in precipitation and temperature, the probability of high total arsenic and trivalent arsenic and arsenic exposure risk was widely reduced. However, the probability of high total arsenic and trivalent arsenic and arsenic exposure risk was mainly observed in low-arsenic areas from SSP126 to SSP585. In conclusion, the consumption of groundwater for human and livestock drinking remains a threat to human health due to high arsenic exposure under future climate scenarios.


Asunto(s)
Arsénico , Agua Subterránea , Contaminantes Químicos del Agua , Humanos , Arsénico/análisis , Clima , Estaciones del Año , Temperatura , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente
16.
Environ Sci Pollut Res Int ; 30(3): 8226-8238, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36056284

RESUMEN

The Tibetan Plateau (TP) is known as the water tower of Asia, and the water quality has long been a focus of public concern, especially in the Yarlung Tsangpo River Basin (YTRB), a unique area that is climate-sensitive, geologically complex, eco-fragile, and densely populated. Thallium (Tl) is a typical metal that is more toxic than Pb, Cd, and As and often occurs in sulfide minerals. Although large-scale polymetallic sulfide mineralization developed in the YTRB, the geochemical dispersion and potential risk of Tl in aquatic environments of the YTRB remain poorly understood. In this study, the concentration, distribution, source, and health risk of Tl and associated metal(loid)s in the hot springs and surface water in the YTRB were systematically analyzed. The results showed that the trace elements (Cd, Cr, Zn, Cu, Al, Sr, Ni, Co, Mn, Pb) in water environments are within the recommended limits, except for Tl and As. Principal component analysis (PCA) and correlation analysis (CA) showed that the elements of Tl and As were positively related to each other in either both hot spring water and surface water, indicating their common origin. Spatial variations suggested that high levels of Tl and As observed in the north YTRB, which may be relevant to the reduction-dissolution of Tl (As)-bearing minerals and the magmatic hydrothermal system formed in the shallow part of the northern YTRB. Furthermore, source apportionment identified natural sources of Cu, Ni, Cr, Co, Mn, Zn, and Cd and anthropogenic inputs of Al and Pb. Exposure assessment studies have found that ingestion is the primary route of As and Tl exposure to local population, and balneological and bathing purposes do not constitute a human health concern. This study offers valuable insights into the risk of naturally occurring Tl enrichment being hidden in As-rich hydrosphere in the YTRB and other regions with similar geoenvironmental contexts.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Humanos , Talio/análisis , Metales Pesados/análisis , Tibet , Cadmio/análisis , Ríos , Plomo/análisis , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente/métodos , Medición de Riesgo , Sulfuros/análisis , China
17.
J Microbiol Immunol Infect ; 56(2): 257-266, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36127231

RESUMEN

BACKGROUND: The exploration of virology knowledge was limited by the optical technology for the observation of virus. Previously, a three-dimensional multi-resolution real-time microscope system (3D-MRM) was developed to observe the uptake of HIV-1-tat peptide-modified nanoparticles in cell membrane. In this study, we labeled HIV-1 virus-like particles (VLPs) with passivated giant quantum dots (gQDs) and recorded their interactive trajectories with human Jurkat CD4 cells through 3D-MRM. METHODS: The labeled of gQDs of the HIV-1 VLPs in sucrose-gradient purified viral lysates was first confirmed by Cryo-electronic microscopy and Western blot assay. After the infection with CD4 cells, the gQD-labeled VLPs were visualized and their extracellular and intracellular trajectories were recorded by 3D-MRM. RESULTS: A total of 208 prime trajectories was identified and classified into three distinct patterns: cell-free random diffusion pattern, directional movement pattern and cell-associated movement pattern, with distributions and mean durations were 72.6%/87.6 s, 9.1%/402.7 s and 18.3%/68.7 s, respectively. Further analysis of the spatial-temporal relationship between VLP trajectories and CD4 cells revealed the three stages of interactions: (1) cell-associated (extracellular) diffusion stage, (2) cell membrane surfing stage and (3) intracellular directional movement stage. CONCLUSION: A complete trajectory of HIV-1 VLP interacting with CD4 cells was presented in animation. This encapsulating method could increase the accuracy for the observation of HIV-1-CD4 cell interaction in real time and three dimensions.


Asunto(s)
Linfocitos T CD4-Positivos , Membrana Celular , VIH-1 , Microscopía Electrónica , Puntos Cuánticos , Productos del Gen tat del Virus de la Inmunodeficiencia Humana , Humanos , Linfocitos T CD4-Positivos/fisiología , Linfocitos T CD4-Positivos/ultraestructura , Linfocitos T CD4-Positivos/virología , VIH-1/fisiología , VIH-1/ultraestructura , Imagenología Tridimensional/métodos , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/fisiología , Péptidos de Penetración Celular/fisiología , Membrana Celular/fisiología , Membrana Celular/ultraestructura , Membrana Celular/virología , Nanopartículas/ultraestructura , Nanopartículas/virología , Partículas Similares a Virus Artificiales/fisiología , Microscopía Electrónica/métodos
18.
Cancer Nurs ; 45(1): E206-E228, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-33214516

RESUMEN

BACKGROUND: Up-to-date research from low- and middle-income countries is needed to inform local pediatric cancer nursing care and share best practices from these settings. Access to all current Chinese-language publications on pediatric oncology nursing research is limited because of a language barrier. OBJECTIVE: The aim of this study was to document the volume, type of research study, and yearly and geographical distribution of published pediatric oncology nursing research in Mainland China and evaluate their content and quality. METHODS: A systematic search was performed for published pediatric oncology research conducted by nurses in Mainland China (2008-2018), using 3 English databases and 3 Chinese databases. Included articles were evaluated using the Johns Hopkins Nursing Evidence-Based Practice Research Evidence Appraisal for strength and quality of evidence. RESULTS: A total of 133 articles were included: 106 in Chinese and 27 in English. Most studies showed level III evidence (88/133) and were rated as good quality (81/133). The most frequently researched topics were psychosocial care, clinical nursing practice, and psychometric testing, which accounted for 63.2% of all publications. CONCLUSIONS: Progress in pediatric oncology nursing research capacity among Mainland China is promising. To gain higher-quality evidence and make existing evidence transferable for nursing practice, optimization of specific research topics is still needed. IMPLICATIONS FOR PRACTICE: In Mainland China, developing interventions to address the symptoms of children with cancer and caregivers' psychosocial issues based on local nursing research should be prioritized. Some synthesized findings of this review may serve as guidance for the future of pediatric oncology nursing science in similar settings.


Asunto(s)
Neoplasias , Investigación en Enfermería , Niño , China , Humanos , Oncología Médica , Enfermería Oncológica , Enfermería Pediátrica
19.
Ann Palliat Med ; 11(12): 3743-3754, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36635999

RESUMEN

BACKGROUND: In hemodialysis (HD) patients, anemia is greatly improved due to regular weekly use of iron and erythropoietin (EPO), but a large number of patients still show persistent anemia. We do a survey to elucidate the influencing factors that contribute to the failure of hemoglobin (Hb) to meet the standard and provide epidemiological data reference for promoting the recognition of renal anemia and improving the treatment effect of renal anemia. METHODS: The clinical data of End-Stage Renal Disease (ESRD) HD patients in 22 tertiary hospital HD centers in Liaoning Province from September 2021 to June 2022 were collected by convenient sampling. According to the 2012 Kidney Disease: Improving Global Outcomes (KDIGO) anemia diagnostic criteria. The standard of Hb compliance: Hb ≥110 g/L is considered as Hb compliant, and Hb <110 g/L as Hb non-compliant. The factors influencing Hb up-to-standard in ESRD HD patients and their correlations were analyzed by comparison between the two groups. RESULTS: The results of this study showed that among the 1,652 ESRD patients investigated in Liaoning Province, the prevalence rate of anemia was 89.29% (1,475/1,652), and the Hb compliance rate was 46.25% (764/1,652). The Hb compliance rate in maintenance hemodialysis (MHD) patients with different primary diseases was statistically significant (P<0.05). Compared with the Hb non-standard group, the gender, dialysis access, HD frequency, concurrent infection, primary disease of ESRD patients, red blood cell (RBC) count, hematocrit (HCT), mean RBC Hb concentration, mean RBC Hb content, platelet (PLT), albumin (ALB), total protein (TP), serum creatinine (Cr), serum calcium (Ca), serum potassium (K), ferritin (Fer), serum iron (SI), and transferrin (TRE) saturation were significantly different between both groups (P<0.05). Adrenaline was an independent risk factor affecting Hb failure in ESRD patients (OR =1.001, 95% CI: 1.000-1.002); dialysis frequency (OR =0.726, 95% CI: 0.601-0.878), ALB (OR =0.959, 95% CI: 0.929-0.990), TP (OR =0.982, 95% CI: 0.968-0.996), serum Cr (OR =0.959, 95% CI: 0.929-0.999), and SI (OR =0.961, 95% CI: 0.940-0.982) were protective factors affecting Hb failure in ESRD patients (P<0.05). Pearson correlation analysis showed that ALB, TP, serum Cr, serum Ca, serum K, SI, and TRE saturation were positively correlated with Hb (P<0.05). CONCLUSIONS: The anemia rate of ESRD patients treated with MHD in Liaoning Province is high. Based on the results, increasing the frequency of dialysis can improve anemia. Parathyroid hormone levels need to be controlled.


Asunto(s)
Anemia , Fallo Renal Crónico , Humanos , Diálisis Renal , Estudios Transversales , Prevalencia , Anemia/epidemiología , Anemia/etiología , Hierro , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/terapia , Hemoglobinas/análisis , Hemoglobinas/metabolismo , Hemoglobinas/uso terapéutico , Albúminas/análisis , Albúminas/uso terapéutico
20.
Dis Colon Rectum ; 54(4): 418-24, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21383561

RESUMEN

BACKGROUND: Stapled transanal rectal resection is a novel surgery for obstructed defecation syndrome. Few data on the functional and morphologic outcome after the surgery have been reported. OBJECTIVE: This study aimed to evaluate the functional and morphologic outcome after stapled transanal rectal resection. DESIGN: This is a prospective study of consecutive patients undergoing transanal rectal resection. SETTING: The study was conducted at a tertiary referral hospital, Beijing, China, from May 2007 to May 2009. PARTICIPANTS: Eighty-six consecutive female patients with obstructed defecation syndrome were carefully selected. INTERVENTIONS: All patients underwent stapled transanal rectal resection. MAIN OUTCOME MEASURES: The main outcome measures were patients' symptoms, obstructed defecation syndrome score, Wexner incontinence score, anorectal manometry and defecography before and 1 year after surgery. RESULTS: The occurrence of all symptoms were significantly reduced after the procedure (P < .0001). Obstructed defecation syndrome score was decreased from 18.17 ± 4.68 preoperatively to 7.36 ± 3.52 postoperatively (P < .0001) with the Wexner incontinence score unchanged. Maximum tolerable rectal volume was significantly decreased (236.08 ± 50.00 vs 205.25 ± 29.60, P < .0001) after surgery with anal sphincter pressures unchanged. Postoperative defecography was performed in 64 patients. Rectocele disappeared in 40 of 62 patients. The depth of rectocele was reduced from 35.40 ± 4.58 mm preoperatively to 19.77 ± 9.19 mm postoperatively (P < .0001). Incomplete evacuation disappeared in 41 of 51 patients. Intussusception was completely corrected in 39 of 56 patients. The reduction of obstructed defection syndrome score was greater in patients with both rectocele and intussusception corrected than others (12.75 ± 2.24 vs 9.17 ± 3.47; P < .0001). LIMITATIONS: This study was limited owing to the lack of a control group and the medium-term results. CONCLUSIONS: Stapled transanal rectal resection is an effective procedure for obstructed defecation syndrome. The functional outcome is good with the preservation of sphincter function and continence postoperatively. The morphologic outcome confirmed its efficacy in correcting rectocele and intussusception, and correlated well with clinical improvement.


Asunto(s)
Defecación/fisiología , Procedimientos Quirúrgicos del Sistema Digestivo/métodos , Enfermedades del Recto/cirugía , Grapado Quirúrgico/métodos , Adulto , Anciano , Defecografía , Femenino , Humanos , Masculino , Manometría , Persona de Mediana Edad , Estudios Prospectivos , Calidad de Vida , Recuperación de la Función , Enfermedades del Recto/fisiopatología , Estadísticas no Paramétricas , Síndrome , Resultado del Tratamiento
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