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1.
J Neurooncol ; 164(2): 397-404, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37650954

RESUMEN

OBJECTIVE: Primary intracranial angiosarcomas (PIAs) are exceedingly uncommon, with the literature predominantly comprising case reports. The clinical characteristics and prognosis of this condition remain elusive. Our objective is to describe the clinical characteristics and surgical prognosis of this rare disease while offering insights into the most effective contemporary treatment strategy. METHODS: The authors of this article incorporated a cohort of 28 cases of PIAs, consisting of 3 from our institution and 25 from previously documented literature sources. Subsequently, we conducted both Cox univariate and multivariate analyses to assess the potential risk factors influencing overall survival (OS). RESULTS: The cohort include 19 males and 9 females with a mean age of 39.6 ± 23.5 years (range: 0.03-73 years). Radiologically, 24 cases were located at supratentorial area, while only 4 cases were located at infratentorial area. 17 cases underwent gross total resection (GTR), and 11 cases underwent Non-GTR. Postoperative radiotherapy was administered to 17 cases, and postoperative chemotherapy was administered to 6 cases. After a mean follow-up time of 21.5 ± 26.4 months, 19 (67.9%) patients died. The 1-year, 2-year, 5-year OS is 55.3%, 50.7% and 24.6%, respectively. Univariate and multivariate Cox regression analysis showed that Non-GTR was the sole factor predicting a shorter OS (p = 0.004). CONCLUSION: In this study, we found that PIAs have a higher incidence in males than in females, and most cases show evidence of old hemorrhage on preoperative MRI. Through our statistical analysis, GTR plays a crucial role in for treating this rare disease. Further clinical data are needed to validate our conclusions.


Asunto(s)
Hemangiosarcoma , Masculino , Femenino , Humanos , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Hemangiosarcoma/cirugía , Enfermedades Raras , Resultado del Tratamiento , Pronóstico , Factores de Riesgo , Estudios Retrospectivos
2.
J Environ Manage ; 331: 117348, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-36706603

RESUMEN

The most commonly used model in constructed wetlands is the first-order removal model, and first order kinetic constants (k) are the key parameters. The presumption is often made that k are constants. However, it is possible that k are functions of operating conditions, but the influence of operation conditions on k is unclear. In this study, response surface methodology was used to explore the variation patterns of ka (area rate constants) and kV (volume rate constants) for the removal of total nitrogen (TN) and total phosphorus (TP) in free water surface (FWS) wetlands. The experimental variables included hydraulic loading rate (HLR), water depth, and inlet concentration (Cin). The results showed that kV was more variable than ka, and the area-based first-order model is more suitable for simulating TN and TP in FWS wetlands. Inlet concentration (Cin) was significant for ka; Cin and water depth were significant for kV; HLR and the interaction between factors were insignificant. The effects of Cin on ka and kV can be described by an upward convex quadratic curve, while the effect of water depth on kV demonstrates a downward convex quadratic curve. The first-order area rate constant for TN removal was given by k = -47.66 + 22.01 Cin - 1.154 Cin2; the first-order area rate constant for TP removal was given by k = -27.75 + 95.88 Cin - 30.73 Cin2. Based on the variation patterns, the traditional k-C model was modified to the kψ-C model. The kψ-C model produced the best results at simulating the outlet concentration and removal efficiency (RE).


Asunto(s)
Eliminación de Residuos Líquidos , Purificación del Agua , Eliminación de Residuos Líquidos/métodos , Purificación del Agua/métodos , Humedales , Nitrógeno , Fósforo , Agua
3.
J Environ Manage ; 344: 118372, 2023 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-37343474

RESUMEN

Alternate wet and dry (AWD) irrigation and organic fertilizers substitution (OFS) have contrasting effects on CH4 and N2O emissions in rice cultivation. Combining these two practices may be feasible for simultaneous reduction of CH4 and N2O emission from paddy. Hence, we conducted a two-year field experiment to explore the reduction of greenhouse gases under the combination of AWD and OFS. The field experiment which was designed with two irrigation methods (continuous flooding (CF) irrigation and AWD irrigation), and five nitrogen regimes (N0, N135, and N180 represent 0, 135, and 180 kg N ha-1, respectively, ON25 and ON50 represent 25% and 50% OFS for inorganic fertilizer, respectively). The results showed a single-peak emission for CH4 fluxes during the whole rice growing season in all water and nitrogen treatments while the N2O fluxes peak only observed during tillering period with AWD irrigation. AWD irrigation and OFS showed a limited reduction in global warming potential (GWP). These were owing to that AWD irrigation reduced 38.3% CH4 emissions while increase 145.9% N2O emissions when compared to CF irrigation, and the low rate (25%) OFS only reduced CH4 emission by 29.4% while high rate (50%) only reduce N2O emission by 38.8% when compared to conventional inorganic nitrogen fertilizer (N180). Combined AWD and ON25 could maximize the reduction in GWP and yield-scaled GWP, which were reduce 58.0% and 52.5%, respectively, compare to the conventional water and nitrogen management (CF and N180). Furthermore, the structural equation modelling (SEM) indicated that the soil dissolved organic carbon (DOC) and rice aboveground biomass showed a significant positive effect on CH4 fluxes while soil NH4+ with a negative effect, and the soil NH4+, nitrification potential, denitrification potential significant affected N2O fluxes with a positive effect while DOC with a negative effect. These results investigated that 25% OFS rate for inorganic fertilizer could further reduce warming potential in AWD irrigation rice field.


Asunto(s)
Gases de Efecto Invernadero , Oryza , Gases de Efecto Invernadero/análisis , Fertilizantes/análisis , Metano/análisis , Óxido Nitroso/análisis , Suelo/química , Nitrógeno/análisis , Agua , Agricultura/métodos , China
4.
Sensors (Basel) ; 22(9)2022 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-35591058

RESUMEN

Motor function evaluation is a significant part of post-stroke rehabilitation protocols, and the evaluation of wrist motor function helps provide patients with individualized rehabilitation training programs. However, traditional assessment is coarsely graded, lacks quantitative analysis, and relies heavily on clinical experience. In order to objectively quantify wrist motor dysfunction in stroke patients, a novel quantitative evaluation system based on force feedback and machine learning algorithm was proposed. Sensors embedded in the force-feedback robot record the kinematic and movement data of the subject, and the rehabilitation doctor used an evaluation scale to score the wrist function of the subject. The quantitative evaluation models of wrist motion function based on random forest (RF), support vector machine regression (SVR), k-nearest neighbor (KNN), and back propagation neural network (BPNN) were established, respectively. To verify the effectiveness of the proposed quantitative evaluation system, 25 stroke patients and 10 healthy volunteers were recruited in this study. Experimental results show that the evaluation accuracy of the four models is all above 88%. The accuracy of BPNN model is 94.26%, and the Pearson correlation coefficient between model prediction and clinician scores is 0.964, indicating that the BPNN model can accurately evaluate the wrist motor function for stroke patients. In addition, there was a significant correlation between the prediction score of the quantitative assessment system and the physician scale score (p < 0.05). The proposed system enables quantitative and refined assessment of wrist motor function in stroke patients and has the feasibility of helping rehabilitation physicians in evaluating patients' motor function clinically.


Asunto(s)
Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular , Retroalimentación , Humanos , Accidente Cerebrovascular/diagnóstico , Rehabilitación de Accidente Cerebrovascular/métodos , Extremidad Superior , Muñeca
5.
Sensors (Basel) ; 22(3)2022 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-35161913

RESUMEN

Rehabilitation training and movement evaluation after stroke have become a research hotspot as stroke has become a very common and harmful disease. However, traditional rehabilitation training and evaluation are mainly conducted under the guidance of rehabilitation doctors. The evaluation process is time-consuming and the evaluation results are greatly influenced by doctors. In this study, a desktop upper limb rehabilitation robot was designed and a quantitative evaluation system of upper limb motor function for stroke patients was proposed. The kinematics and dynamics data of stroke patients during active training were collected by sensors. Combined with the scores of patients' upper limb motor function by rehabilitation doctors using the Wolf Motor Function Test (WMFT) scale, three different quantitative evaluation models of upper limb motor function based on Back Propagation Neural Network (BPNN), K-Nearest Neighbors (KNN), and Support Vector Regression (SVR) algorithms were established. To verify the effectiveness of the quantitative evaluation system, 10 healthy subjects and 21 stroke patients were recruited for experiments. The experimental results show that the BPNN model has the best evaluation performance among the three quantitative evaluation models. The scoring accuracy of the BPNN model reached up to 87.1%. Moreover, there was a significant correlation between the models' scores and the doctors' scores. The proposed system can help doctors to quantitatively evaluate the upper limb motor function of stroke patients and accurately master the rehabilitation progress of patients.


Asunto(s)
Robótica , Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular , Fenómenos Biomecánicos , Humanos , Recuperación de la Función , Accidente Cerebrovascular/diagnóstico , Extremidad Superior
6.
Nano Lett ; 21(22): 9729-9735, 2021 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-34761680

RESUMEN

Unveiling the internal dynamics of rotation in molecular machine at single-molecule scale is still a challenge. In this work, three crank-shaped molecules are elaborately designed with the conformational flipping between syn and anti fulfilled by two naphthyl groups rotating freely along 1,3-butadiynyl axis. By investigating the single-molecule conductance using scanning tunnelling microscope break junction (STM-BJ) technique and theoretical simulation, the internal rotation of these crank-shaped molecules is well identified through low and high conductance corresponding to syn- and anti-conformations. As demonstrated by theoretically computational study, the orbital energy changes with the conformational flipping and influences the intraorbital quantum interference, thus eventually modulating the single-molecule conductance. This work demonstrates single-molecule conductance measurement to be a rational approach for characterizing the internal rotation of molecular machines.


Asunto(s)
Conformación Molecular , Nanotecnología , Rotación , Simulación por Computador
7.
J Exp Bot ; 72(4): 1073-1084, 2021 02 24.
Artículo en Inglés | MEDLINE | ID: mdl-33180933

RESUMEN

The primary cell walls of plants provide mechanical strength while maintaining the flexibility needed for cell extension growth. Cell extension involves loosening the bonds between cellulose microfibrils, hemicelluloses and pectins. Pectins have been implicated in this process, but it remains unclear if this depends on the abundance of certain pectins, their modifications, and/or structure. Here, cell wall-related mutants of the model plant Arabidopsis were characterized by biochemical and immunohistochemical methods and Fourier-transform infrared microspectroscopy. Mutants with reduced pectin or hemicellulose content showed no root cell elongation in response to simulated drought stress, in contrast to wild-type plants or mutants with reduced cellulose content. While no association was found between the degrees of pectin methylesterification and cell elongation, cell wall composition analysis suggested an important role of the pectin rhamnogalacturonan II (RGII), which was corroborated in experiments with the RGII-modifying chemical 2ß-deoxy-Kdo. The results were complemented by expression analysis of cell wall synthesis genes and microscopic analysis of cell wall porosity. It is concluded that a certain amount of pectin is necessary for stress-induced root cell elongation, and hypotheses regarding the mechanistic basis of this result are formulated.


Asunto(s)
Arabidopsis , Pared Celular/química , Pectinas/química , Raíces de Plantas/crecimiento & desarrollo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Celulosa , Raíces de Plantas/citología
8.
Neurosurg Rev ; 44(5): 2755-2765, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33409764

RESUMEN

At present, limited data exists to discuss the characteristics of suprasellar arachnoid cysts (SACs). The aim of this study is to elucidate the relationship between characteristics of cysts and outcomes, quantitatively analyze improvement in hydrocephalus, and evaluate the risk factors for the prognosis of SACs treated by endoscope. From June 2002 to 2017 December, 247 cases of SACs treated by endoscope in Beijing Tiantan Hospital were included in this study. The severity of hydrocephalus was evaluated by Evans' index (EI). The results showed that the slit-valve and the transparent/thin membrane were noted in 86.2% and 76.5% of overall patients, respectively, and the distribution differences among age-groups were statistically significant (p < 0.01). After a mean follow-up duration of 73.1 months, 18 patients underwent a reoperation. Ventriculocystostomy (VC) (hazard ratio (HR), 3.37; 95% confidence interval (CI), 1.2-9.47; p = 0.024) and history of treatment (HR, 3.98; 95% CI, 1.31-12.31; p = 0.015) were adverse factors for reoperation rate. MRI at 1-year follow-up revealed mean decreases of 78.4% and 9.13% in cyst size and EI. No paraventricular edema was an adverse factor associated with the improvement in hydrocephalus (HR, 11.22; 95% CI, 5.43-23.18; p < 0.01). These results indicated that ventriculocystocisternostomy (VCC) and no history of treatment is favorable factors for prognosis of SACs treated by endoscope. If feasible, VCC is the optimal choice for SACs. Slit-valve phenomenon and transparent/thin membrane are correlated with age but did not influence the outcomes of endoscopic fenestration. The mechanism for the expansion of cysts may be different between child and adult patients. Paraventricular edema is a favorable factor for the improvement in hydrocephalus after endoscopic surgery.


Asunto(s)
Quistes Aracnoideos , Hidrocefalia , Adulto , Quistes Aracnoideos/diagnóstico , Quistes Aracnoideos/epidemiología , Quistes Aracnoideos/cirugía , Niño , Endoscopía , Estudios de Seguimiento , Humanos , Hidrocefalia/etiología , Hidrocefalia/cirugía , Imagen por Resonancia Magnética , Resultado del Tratamiento
9.
Neurosurg Rev ; 44(3): 1645-1653, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32712745

RESUMEN

A tendency for suprasellar arachnoid cysts (SACs) to occur in young children is known. Data of adult SACs were rare in previous reports. The aim of this study is to discuss their clinical presentations, radiological features, and treatment outcomes based on 23 adult patients who underwent endoscopic fenestration in our hospital between January 2003 and December 2018. Preoperative cyst volume ranged from 12.3 to 72.5 cm3 (mean 39.8 ± 19.8). Endocrine disorders occurred in 7 (30.4%) patients. Hydrocephalus was observed in 20 patients. In the patients with hydrocephalus, the mean preoperative Evans' index (EI) (%) and frontooccipital horn ratio (FOHR) (%) were 44.8 (ranged 32.2-63.4) and 49.6 (ranged 36.7-59.8), respectively. A bivariate correlation showed significant positive association between preoperative cyst volume and preoperative EI or FOHR (Pearson correlation, r = 0.607, p = 0.005; r = 0.583, p = 0.007). The slit-valve phenomenon was observed in 13 (56.5%) patients. Pale/tenacious cyst walls were observed in 12 (52.2%) patients. Postoperatively, all patients achieved the improvement in clinical symptoms and a decrease in cyst size. The mean decreases in cyst volume, EI, and FOHR were 64.7%, 7.89%, and 5.8%, respectively. A bivariate correlation indicated the irrelevance between the postoperative cyst volume and postoperative EI or FOHR (Pearson correlation: r = 0.37, p = 0.11; r = 0.43, p = 0.054). These results reveal that there are a few differences in several aspects between adult patients and child patients. The severity of hydrocephalus is correlated with cyst size in adult patients. Additionally, the excellent outcomes in adult SACs can be obtained by endoscopic fenestration.


Asunto(s)
Quistes Aracnoideos/diagnóstico por imagen , Quistes Aracnoideos/cirugía , Imagen por Resonancia Magnética/tendencias , Neuroendoscopía/tendencias , Tomografía Computarizada por Rayos X/tendencias , Adolescente , Adulto , Quistes Aracnoideos/complicaciones , Femenino , Estudios de Seguimiento , Humanos , Hidrocefalia/diagnóstico por imagen , Hidrocefalia/etiología , Hidrocefalia/cirugía , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
10.
J Am Chem Soc ; 142(38): 16493-16505, 2020 09 23.
Artículo en Inglés | MEDLINE | ID: mdl-32830966

RESUMEN

An efficient catalytic method to convert an α-C-H bond of N-alkylamines into an α-C-alkynyl bond was developed. In the past, such transformations were carried out under oxidative conditions, and the enantioselective variants were confined to tetrahydroisoquinoline derivatives. Here, we disclose a method for the union of N-alkylamines and trimethylsilyl alkynes, without the presence of an external oxidant and promoted through cooperative actions of two Lewis acids, B(C6F5)3 and a Cu-based complex. A variety of propargylamines can be synthesized in high diastereo- and enantioselectivity. The utility of the approach is demonstrated by the late-stage site-selective modification of bioactive amines. Kinetic investigations that shed light on various mechanistic nuances of the catalytic process are presented.


Asunto(s)
Aminas/química , Cobre/química , Ácidos de Lewis/química , Compuestos Organometálicos/química , Pargilina/análogos & derivados , Propilaminas/síntesis química , Catálisis , Estructura Molecular , Pargilina/síntesis química , Pargilina/química , Propilaminas/química , Estereoisomerismo
11.
J Immunol ; 201(7): 2132-2140, 2018 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-30111633

RESUMEN

Translating studies on T cell function and modulation from mouse models to humans requires extrapolating in vivo results on mouse T cell responses in lymphoid organs (spleen and lymph nodes [LN]) to human peripheral blood T cells. However, our understanding of T cell responses in human lymphoid sites and their relation to peripheral blood remains sparse. In this study, we used a unique human tissue resource to study human T cells in different anatomical compartments within individual donors and identify a subset of memory CD8+ T cells in LN, which maintain a distinct differentiation and functional profile compared with memory CD8+ T cells in blood, spleen, bone marrow, and lungs. Whole-transcriptome and high-dimensional cytometry by time-of-flight profiling reveals that LN memory CD8+ T cells express signatures of quiescence and self-renewal compared with corresponding populations in blood, spleen, bone marrow, and lung. LN memory T cells exhibit a distinct transcriptional signature, including expression of stem cell-associated transcription factors TCF-1 and LEF-1, T follicular helper cell markers CXCR5 and CXCR4, and reduced expression of effector molecules. LN memory T cells display high homology to a subset of mouse CD8+ T cells identified in chronic infection models that respond to checkpoint blockade immunotherapy. Functionally, human LN memory T cells exhibit increased proliferation to TCR-mediated stimulation and maintain higher TCR clonal diversity compared with memory T cells from blood and other sites. These findings establish human LN as reservoirs for memory T cells with high capacities for expansion and diverse recognition and important targets for immunotherapies.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Inmunoterapia/métodos , Ganglios Linfáticos/inmunología , Factor 1 de Transcripción de Linfocitos T/metabolismo , Animales , Anticuerpos Monoclonales , Biodiversidad , Autorrenovación de las Células , Células Clonales , Receptores Coestimuladores e Inhibidores de Linfocitos T/inmunología , Humanos , Memoria Inmunológica , Factor de Unión 1 al Potenciador Linfoide/metabolismo , Ratones , Receptores de Antígenos de Linfocitos T/metabolismo , Transducción de Señal , Transcriptoma
12.
J Am Chem Soc ; 141(37): 14570-14575, 2019 09 18.
Artículo en Inglés | MEDLINE | ID: mdl-31480842

RESUMEN

An efficient deuteration process of ß-amino C-H bonds in various N-alkylamine-based pharmaceutical compounds has been developed. Catalytic reactions begin with the action of Lewis acidic B(C6F5)3 and Brønsted basic N-alkylamine, converting a drug molecule into the corresponding enamine. The acid/base catalysts also promote the dedeuteration of acetone-d6 to afford a deuterated ammonium ion. Ensuing deuteration of the enamine then leads to the formation of ß-deuterated bioactive amines with up to 99% deuterium incorporation.


Asunto(s)
Deuterio/química , Preparaciones Farmacéuticas/química , Aminas/química , Catálisis
13.
Angew Chem Int Ed Engl ; 57(18): 5129-5133, 2018 04 23.
Artículo en Inglés | MEDLINE | ID: mdl-29512253

RESUMEN

The first example of PdII -catalyzed enantioselective C-H olefination with non-chiral or racemic sulfoxides as directing groups was developed. A variety of chiral diaryl sulfoxides were synthesized with high enantioselectivity (up to 99 %) through both desymmetrization and parallel kinetic resolution (PKR). This is the first report of PdII -catalyzed enantioselective C(sp2 )-H functionalization through PKR, and it represents a novel strategy to construct sulfur chiral centers.

14.
Mutat Res ; 828: 111852, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38368811

RESUMEN

OBJECTIVES: Our group previously found that LINC00665 was upregulated in hepatocellular carcinoma (HCC) tissues through database analysis; however, the potential molecular mechanism of LINC00665 in HCC progression still needs further study. METHODS: qRTPCR was performed to determine the differential expression of LINC00665 and let-7i in HCC cells. Dual-luciferase reporter assays were performed to analyze the interaction of LINC00665 and let-7i. CCK-8 assays, scratch assays, Transwell invasion assays, qRTPCR and western blotting were performed to determine the regulatory mechanism of LINC00665/let-7i/HMGA1 in HCC cells. RESULTS: LINC00665 was upregulated in HCC cells compared with normal hepatocytes. A potential binding site between LINC00665 and let-7i was confirmed by dual-luciferase reporter assay. In HCC cells, inhibition of LINC00665 significantly reduced cell proliferation, migration and invasion ability via the let-7i/HMGA1 signaling axis. CONCLUSION: LINC00665 promotes the proliferation and invasion of HCC cells via the let-7i/HMGA1 signaling axis.


Asunto(s)
Carcinoma Hepatocelular , Movimiento Celular , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Proteína HMGA1a , Neoplasias Hepáticas , MicroARNs , Invasividad Neoplásica , ARN Largo no Codificante , Humanos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Proteína HMGA1a/genética , Proteína HMGA1a/metabolismo , Línea Celular Tumoral , Transducción de Señal
15.
Vet Sci ; 11(4)2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38668443

RESUMEN

Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) play key roles in regulating testosterone secretion and spermatogenesis in male mammals, respectively, and they maintain the fertility of male animals by binding to their corresponding receptors. We designed and prepared a recombinant LH receptor (LHR) subunit vaccine and a recombinant FSH receptor (FSHR) subunit vaccine and used male Sprague Dawley (SD) rats as a model to examine their effects on testicular development, spermatogenesis, and testosterone secretion in prepubertal and pubertal mammals. Both vaccines (LHR-DTT and FSHR-DTT) significantly decreased the serum testosterone level in prepubertal rats (p < 0.05) but had no effect on the testosterone secretion in pubertal rats; both vaccines decreased the number of cell layers in the seminiferous tubules and reduced spermatogenesis in prepubertal and pubertal rats. Subunit vaccine FSHR-DTT decreased the sperm density in the epididymis in both prepubertal and pubertal rats (p < 0.01) and lowered testicular index and sperm motility in pubertal rats (p < 0.05), whereas LHR-DTT only reduced the sperm density in the epididymis in pubertal rats (p < 0.05). These results indicate that the FSHR subunit vaccine may be a promising approach for immunocastration, but it still needs improvements in effectiveness.

16.
Anal Chem ; 85(9): 4507-11, 2013 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-23607453

RESUMEN

Matrix effect is unavoidable in direct solid analysis, which usually is a leading cause of the nonstoichiometric effect in quantitative analysis. In this research, experiments were carried out to study the overall characteristics of atomization and ionization in laser-solid interaction. Both nanosecond (ns) and femtosecond (fs) lasers were applied in a buffer-gas-assisted ionization source coupled with an orthogonal time-of-flight mass spectrometer. Twenty-nine solid standards of ten different matrices, including six metals and four dielectrics, were analyzed. The results indicate that the fs-laser mode offers more stable relative sensitivity coefficients (RSCs) with irradiance higher than 7 × 10(13) W·cm(-2), which could be more reliable in the determination of element composition of solids. The matrix effect is reduced by half when the fs-laser is employed, owing to the fact that the fs-laser ablation and ionization (fs-LAI) incurs an almost heat-free ablation process and creates a dense plasma for the stable ionization.


Asunto(s)
Rayos Láser , Metales/análisis , Suelo/química , Sulfuros/análisis , Iones/química , Metales/química , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Sulfuros/química , Factores de Tiempo
17.
Anal Chem ; 85(9): 4268-72, 2013 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-23544353

RESUMEN

In modern bioanalytics, elemental analysis of single cells is important yet challenging due to the complicated biological matrices and elemental contents. We have developed the high irradiance femtosecond laser ionization orthogonal time-of-flight mass spectrometry (fs-LI-O-TOFMS) to determine the elemental composition of individual cells. The sample preparation procedure is simple and fast through heating and drying the cells. Under typical operating conditions, elements above femtogram levels in a single cell can be clearly observed in the spectrum with reasonable isotope ratios. Some of the nonmetallic elements that are difficult to measure by ICPMS, such as P, S, and Cl, can be easily determined by fs-LI-O-TOFMS. Replicate analyses show that signal variations are 15-35% for metallic elements and 25-50% for nonmetallic elements. The results demonstrate that fs-LI-O-TOFMS is a simple, rapid, and practical tool for the elemental determination of single cells.


Asunto(s)
Rayos Láser , Paramecium/citología , Análisis de la Célula Individual , Análisis de la Célula Individual/instrumentación , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/instrumentación , Factores de Tiempo
18.
Artículo en Inglés | MEDLINE | ID: mdl-36901657

RESUMEN

Based on the panel data of prefecture-level cities in China from 2006 to 2019, this paper uses the PSM-DID method to empirically test the internal impact mechanism among high-speed railway opening, inter-regional factor allocation efficiency, and urban environmental governance. The research results show that: (1) There is a serious factor-misallocation problem among prefecture-level cities in China. From 2006 to 2019, the factor misallocation between prefecture-level cities led to an average annual loss of total factor productivity in China's economy of 52.5%, an average labor misallocation of 23.16%, and an average capital misallocation of 18.69%. Since 2013, capital misallocation has exceeded labor misallocation as the main reason for factor misallocation among prefecture-level cities in China. (2) The opening of high-speed railways can promote the efficiency of urban factor allocation through the technological innovation effect, the foreign investment attraction effect, and the population agglomeration effect. The improvement of urban factor allocation efficiency can promote the improvement of urban environmental quality through the effects of industrial structure optimization, income enhancement, and human capital agglomeration. Therefore, the opening of a high-speed railway can improve urban environmental quality through the intermediary effect of improving the efficiency of urban factor allocation; that is, the opening of a high-speed railway has a dual positive effect of economic efficiency and environmental quality improvement. (3) The optimization effect of factor allocation and the environmental governance effect of the opening of high-speed railways have strong urban scale heterogeneity, urban characteristic heterogeneity, and regional heterogeneity. The research content of this paper has important guiding significance for the construction of China's new development paradigm, accelerating the construction of "a unified national market," and green and low-carbon development.


Asunto(s)
Conservación de los Recursos Naturales , Mejoramiento de la Calidad , Humanos , Política Ambiental , Asignación de Recursos , Carbono , China , Ciudades , Desarrollo Económico , Eficiencia
19.
PLoS One ; 18(10): e0292927, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37883356

RESUMEN

This paper aims to study the impact of correcting the factor misallocation among China's three major industries on China's income gap and income distribution pattern. By using the industry Panel data at the provincial level in China, we measure the degree of factor misallocation among the three major industries in China's provinces from 2002 to 2019 by building a factor misallocation measurement model, and then uses reverse thinking to compare the income gap under the condition of no factor misallocation with the actual income gap, and then obtains the impact of factor misallocation on the income gap, And use this method to focus on analyzing the impact of factor allocation efficiency changes among the three industries on income distribution pattern. The research finds that: (1) There is a serious factor misallocation among the three major industries in each province. From the perspective of subdivided factors, the factor misallocation among the three major industries in China's provinces is mainly caused by labor misallocation. Factor misallocation shows a trend of convergence first and then divergence among regions. (2) There is a strong heterogeneity in the explanatory power of different dimensions of the income gap of factor misallocation among the three major industries in China's provinces. Among them, correcting the misallocation of total factors among the three major industries in China's provinces can only narrow the internal income gap of the tertiary sector of the economy, and expand the internal income gap between the primary and secondary industries. (3) The impact of correcting the total misallocation, capital misallocation and labor misallocation among the three industries on the income gap among industries or provinces is narrowing first and then expanding. (4) Further research shows that although the level of factor misallocation among provinces in China is significantly lower than the average level of factor misallocation among the three major industries within each province, it has a stronger explanatory power for the inter-provincial income gap. Correcting the total factor misallocation and labor misallocation among provinces can significantly reduce the inter-provincial income gap in China. Correcting the total factor misallocation and labor misallocation among provinces in 2019 can reduce the inter-provincial income gap by 51.48% and 81.68% respectively. Only correcting the capital misallocation among provinces will expand the inter-provincial income gap, and only correcting the capital misallocation among provinces in 2019 will expand the inter-provincial income gap by 112.21%.


Asunto(s)
Desarrollo Económico , Industrias , China , Renta , Asignación de Recursos , Eficiencia
20.
JMIR Mhealth Uhealth ; 11: e40416, 2023 02 23.
Artículo en Inglés | MEDLINE | ID: mdl-36821348

RESUMEN

BACKGROUND: In contrast to the large and increasing number of patients with stroke, clinical rehabilitation resources cannot meet their rehabilitation needs. Especially for those discharged, ways to carry out effective rehabilitation training without the supervision of physicians and receive guidance from physicians remain urgent problems to be solved in clinical rehabilitation and have become a research hot spot at home and abroad. At present, there are many studies on home rehabilitation training based on wearable devices, Kinect, among others, but these have disadvantages (eg, complex systems, high price, and unsatisfactory rehabilitation effects). OBJECTIVE: This study aims to design a remote intelligent rehabilitation training system based on wearable devices and human-computer interaction training tasks, and to evaluate the effectiveness and safety of the remote rehabilitation training system for nonphysician-supervised motor rehabilitation training of patients with stroke through a clinical trial study. METHODS: A total of 120 inpatients with stroke having limb motor dysfunction were enrolled via a randomized, parallel-controlled method in the rehabilitation institutions, and a 3-week clinical trial was conducted in the rehabilitation hall with 60 patients in the experimental group and 60 in the control group. The patients in the experimental group used the remote rehabilitation training system for rehabilitation training and routine clinical physical therapy (PT) training and received routine drug treatment every day. The patients in the control group received routine clinical occupational therapy (OT) training and routine clinical PT training and routine drug treatment every day. At the beginning of the training (baseline) and after 3 weeks, the Fugl-Meyer Motor Function Rating scale was scored by rehabilitation physicians, and the results were compared and analyzed. RESULTS: Statistics were performed using SAS software (version 9.4). The total mean Fugl-Meyer score improved by 11.98 (SD 8.46; 95% CI 9.69-14.27) in the control group and 17.56 (SD 11.65; 95% CI 14.37-20.74) in the experimental group, and the difference between the 2 groups was statistically significant (P=.005). Among them, the mean Fugl-Meyer upper extremity score improved by 7.45 (SD 7.24; 95% CI 5.50-9.41) in the control group and 11.28 (SD 8.59; 95% CI 8.93-13.62) in the experimental group, and the difference between the 2 groups was statistically significant (P=.01). The mean Fugl-Meyer lower extremity score improved by 4.53 (SD 4.42; 95% CI 3.33-5.72) in the control group and 6.28 (SD 5.28; 95% CI 4.84-7.72) in the experimental group, and there was no significant difference between the 2 groups (P=.06). The test results showed that the experimental group was better than the control group, and that the patients' motor ability was improved. CONCLUSIONS: The remote rehabilitation training system designed based on wearable devices and human-computer interaction training tasks can replace routine clinical OT training. In the future, through medical device registration certification, the system will be used without the participation of physicians or therapists, such as in rehabilitation training halls, and in remote environments, such as communities and homes. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2200061310; https://tinyurl.com/34ka2725.


Asunto(s)
Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular , Telerrehabilitación , Dispositivos Electrónicos Vestibles , Humanos , Rehabilitación de Accidente Cerebrovascular/métodos , Proyectos Piloto , Resultado del Tratamiento
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