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1.
Langenbecks Arch Surg ; 409(1): 164, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38775920

RESUMO

PURPOSE: To explore the risk factors for incisional hernia (IH) recurrence following open prepertioneal repair. METHODS: Patients diagnosed with primary IH who underwent open preperitoneal repair at our hospital were enrolled. Patients were assessed, and perioperative factors were collected. Recurrence surveys were performed at regular intervals throughout the long-term postoperative follow-up. The risk factors for IH recurrence were identified using univariate and multivariate analyses. RESULTS: This study included 145 patients. Significant differences were found between recurrence and non-recurrence patients regarding pulmonary ventilation function (PVT), age, body mass index (BMI), mesh materials, type of surgery (clean, clean-contaminated, or contaminated), surgical site infections (SSIs), maximum width of the hernia defect (MWHD), and site of incisional hernia (P < 0.01). The univariate survival analysis revealed that PVT abnormalities, age > 70 years, BMI > 27 kg/m2, porcine small intestine submucosal (PSIS) mesh, non-clean surgery, SSIs, MWHD > 10 cm, and location in the lateral zones were significant factors for IH recurrence after open preperitoneal repair. The multivariate survival analysis showed that PVT abnormalities, age > 70 years, BMI > 27 kg/m2, and PSIS mesh were independent risk factors for IH recurrence after open preperitoneal repair. CONCLUSIONS: We identified PVT abnormalities, age > 70 years, BMI > 27 kg/m2, and PSIS mesh as novel risk factors for IH recurrence after open preperitoneal repair.


Assuntos
Herniorrafia , Hérnia Incisional , Recidiva , Telas Cirúrgicas , Humanos , Masculino , Feminino , Hérnia Incisional/cirurgia , Hérnia Incisional/etiologia , Estudos Retrospectivos , Fatores de Risco , Idoso , Pessoa de Meia-Idade , Herniorrafia/efeitos adversos , Herniorrafia/métodos , Adulto , Estudos de Coortes , Idoso de 80 Anos ou mais
2.
Updates Surg ; 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38512634

RESUMO

Tension-free hernia repair is the gold standard for groin hernia repair. However, the optimal surgical treatment for incarcerated or strangulated groin hernia in elderly populations is controversial. The aim of this study is to compare the clinical efficacy of mesh repair and suture repair in the treatment of incarcerated or strangulated groin hernia in elderly patients. Patients ≥ 65 years who underwent urgent surgical repair for incarcerated or strangulated groin hernia from January 2012 to June 2022 were included. Patients' demographic data and postoperative outcomes were retrospectively analyzed. Patients with limited life expectancy were screened from the elderly population for subgroup analysis. A total of 103 patients (median age: 84 years old, range 65-96; mean follow-up time: 36.8 ± 24.8 months) were included, involving 42 cases in the suture repair group and 61 cases in the mesh repair group. Suture repair and mesh repair had similar lengths of ICU and hospital stay, and rates of small bowel resection, chronic pain, surgical site infection, and surgical-related death. However, suture repair had a significantly higher recurrence rate than mesh repair (7% vs. 2%, P = 0.04). In our subgroup analysis, for patients with limited life expectancy (41 patients; median age: 88 years old, range: 80-96), suture repair had no statistical difference in postoperative outcomes compared with mesh repair. Mesh repair is suitable for elderly patients with acutely incarcerated or strangulated groin hernias. However, for elderly patients with limited life expectancy, suture repair and mesh repair showed similar clinical outcomes.

3.
J Mater Chem B ; 12(8): 2070-2082, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38305057

RESUMO

The natural healing of diabetic wounds is collectively impeded by multiple factors, including hyperglycemia, angiogenesis disorders, acute oxidative stress, and prolonged inflammation. Although considerable effort has been devoted to solving these problems, the treatment of diabetic wounds remains a major clinical obstacle. In light of this, we developed an innovative wound microenvironment self-adaptive hydrogel to promote the healing of diabetic wounds. The hydrogel was constructed by the crosslinking of 3-aminobenzeneboronic acid (PBA)-modified gelatin (Gel) and polyvinyl alcohol (PVA) by borate ester bonds, which showed high responsiveness to glucose. Meanwhile, the liposomes that encapsulated metformin, L-arginine, and L(+)-ascorbic acid were incorporated into the hydrogel framework. The hydrogel@lipo composite demonstrated shape adaptability, glucose responsiveness, and all-in-one capability, thereby effectively improving the intricate microenvironment of diabetic wounds. In vitro and in vivo experiments demonstrated the ability of hydrogel@lipo to mitigate oxidative stress, enhance angiogenesis, and attenuate inflammatory responses. Consequently, the hydrogel@lipo could accelerate diabetic wound healing (within two weeks). The cumulative findings strongly suggest the potential of hydrogel@lipo as a highly promising therapeutic dressing for advancing diabetic wound recovery.


Assuntos
Diabetes Mellitus , Hidrogéis , Humanos , Hidrogéis/farmacologia , Arginina , Ácido Ascórbico , Glucose
4.
Epilepsia ; 65(1): 46-56, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37347512

RESUMO

OBJECTIVES: Although hemispheric surgeries are among the most effective procedures for drug-resistant epilepsy (DRE) in the pediatric population, there is a large variability in seizure outcomes at the group level. A recently developed HOPS score provides individualized estimation of likelihood of seizure freedom to complement clinical judgement. The objective of this study was to develop a freely accessible online calculator that accurately predicts the probability of seizure freedom for any patient at 1-, 2-, and 5-years post-hemispherectomy. METHODS: Retrospective data of all pediatric patients with DRE and seizure outcome data from the original Hemispherectomy Outcome Prediction Scale (HOPS) study were included. The primary outcome of interest was time-to-seizure recurrence. A multivariate Cox proportional-hazards regression model was developed to predict the likelihood of post-hemispheric surgery seizure freedom at three time points (1-, 2- and 5- years) based on a combination of variables identified by clinical judgment and inferential statistics predictive of the primary outcome. The final model from this study was encoded in a publicly accessible online calculator on the International Network for Epilepsy Surgery and Treatment (iNEST) website (https://hops-calculator.com/). RESULTS: The selected variables for inclusion in the final model included the five original HOPS variables (age at seizure onset, etiologic substrate, seizure semiology, prior non-hemispheric resective surgery, and contralateral fluorodeoxyglucose-positron emission tomography [FDG-PET] hypometabolism) and three additional variables (age at surgery, history of infantile spasms, and magnetic resonance imaging [MRI] lesion). Predictors of shorter time-to-seizure recurrence included younger age at seizure onset, prior resective surgery, generalized seizure semiology, FDG-PET hypometabolism contralateral to the side of surgery, contralateral MRI lesion, non-lesional MRI, non-stroke etiologies, and a history of infantile spasms. The area under the curve (AUC) of the final model was 73.0%. SIGNIFICANCE: Online calculators are useful, cost-free tools that can assist physicians in risk estimation and inform joint decision-making processes with patients and families, potentially leading to greater satisfaction. Although the HOPS data was validated in the original analysis, the authors encourage external validation of this new calculator.


Assuntos
Epilepsia Resistente a Medicamentos , Epilepsia , Hemisferectomia , Espasmos Infantis , Criança , Humanos , Hemisferectomia/métodos , Espasmos Infantis/cirurgia , Estudos Retrospectivos , Fluordesoxiglucose F18 , Resultado do Tratamento , Epilepsia/diagnóstico por imagem , Epilepsia/cirurgia , Convulsões/diagnóstico , Convulsões/etiologia , Convulsões/cirurgia , Epilepsia Resistente a Medicamentos/diagnóstico por imagem , Epilepsia Resistente a Medicamentos/cirurgia , Imageamento por Ressonância Magnética , Eletroencefalografia
5.
Nat Commun ; 14(1): 7012, 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37919285

RESUMO

The search for topological superconductivity (TSC) is currently an exciting pursuit, since non-trivial topological superconducting phases could host exotic Majorana modes. However, the difficulty in fabricating proximity-induced TSC heterostructures, the sensitivity to disorder and stringent topological restrictions of intrinsic TSC place serious limitations and formidable challenges on the materials and related applications. Here, we report a new type of intrinsic TSC, namely intrinsic surface topological superconductivity (IS-TSC) and demonstrate it in layered AuSn4 with Tc of 2.4 K. Different in-plane and out-of-plane upper critical fields reflect a two-dimensional (2D) character of superconductivity. The two-fold symmetric angular dependences of both magneto-transport and the zero-bias conductance peak (ZBCP) in point-contact spectroscopy (PCS) in the superconducting regime indicate an unconventional pairing symmetry of AuSn4. The superconducting gap and surface multi-bands with Rashba splitting at the Fermi level (EF), in conjunction with first-principle calculations, strongly suggest that 2D unconventional SC in AuSn4 originates from the mixture of p-wave surface and s-wave bulk contributions, which leads to a two-fold symmetric superconductivity. Our results provide an exciting paradigm to realize TSC via Rashba effect on surface superconducting bands in layered materials.

6.
Altern Ther Health Med ; 29(8): 856-862, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37708557

RESUMO

Objective: This study aims to determine the variations in myocardial work among patients with essential hypertension at varying risk levels by analyzing the left ventricular pressure-strain loop. Additionally, this research aims to investigate the potential diagnostic significance of myocardial work parameters in identifying myocardial dysfunction in patients with essential hypertension. Methods: We conducted a study with 79 patients who have essential hypertension and 30 healthy adults. The essential hypertension patients were categorized according to their risk level, with 10 patients in the low-risk group, 11 in the medium-risk group, 23 in the high-risk group, and 35 in the very high-risk group. We included 30 healthy adults in the study as a control group. Clinical data such as height, weight, and blood pressure were collected for all groups. Routine echocardiographic dynamic images were collected, and speck tracking echocardiography was performed to analyze global longitudinal strain and myocardial work parameters were detected by the left ventricular pressure-strain loop. Finally, the global work index, global constructive work, global wasted work, global work efficiency, and global longitudinal strain were calculated and compared among groups. The correlation between blood pressure and myocardial work parameters was analyzed. Results: Compared with the control group, inter-ventricular septum thickness was thickened in the medium-risk groups, high-risk groups,and very high-risk groups, P < .001). There was a negative linear correlation between global work efficiency and blood pressure (systolic and diastolic, and a positive linear correlation was observed between blood pressure and global work index, global constructive work, and global wasted work. Conclusion: Left ventricular pressure-strain loop can be used to evaluate changes in left ventricular myocardial work of essential hypertension patients in the early stage and with different risk stratifications.


Assuntos
Hipertensão , Adulto , Humanos , Pressão Ventricular , Volume Sistólico/fisiologia , Hipertensão/complicações , Ecocardiografia/métodos , Hipertensão Essencial
7.
Phys Rev Lett ; 131(8): 086501, 2023 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-37683154

RESUMO

Strong electron correlation under two-dimensional limit is intensely studied in the transition metal dichalcogenides monolayers, mostly within their charge density wave (CDW) states that host a star of David period. Here, by using scanning tunneling microscopy and spectroscopy and density functional theory calculations with on-site Hubbard corrections, we study the VTe_{2} monolayer with a different 2sqrt[3]×2sqrt[3] CDW period. We find that the dimerization of neighboring Te-Te and V-V atoms occurs during the CDW transition, and that the strong correlation effect opens a Mott-like full gap at Fermi energy (E_{F}). We further demonstrate that such a Mott phenomenon is ascribed to the combination of the CDW transition and on-site Coulomb interactions. Our work provides a new platform for exploring Mott physics in 2D materials.

8.
Langmuir ; 39(32): 11304-11316, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37535432

RESUMO

Silane is known as an effective coating for enhancing the resistance of concrete to harmful acids and radicals that are usually produced by the metabolism of microorganisms. However, the mechanism of silane protection is still unclear due to its nanoscale attributes. Here, the protective behavior of silane on the calcium silicate hydrate (C-S-H) surface is examined under the attack environment of nitrate/sulfate ions using molecular dynamics simulations. The findings revealed that silane coating improved the resistance of C-S-H to nitrate/sulfate ions. This resistance is considered the origin of silane protection against harmful ion attacks. Further research on the details of molecular structures suggests that the interaction between the oxygen in the silane molecule and the calcium in C-S-H, which can prevent the coordination of sulfate and nitrate to calcium on the C-S-H surface, is the cause of the silane molecules' strong adsorption. These results are also proved in terms of free energy, which found that the adsorption free energy on the C-S-H surface followed the order silane > sulfate > nitrate. This research confirms the excellent protection performance of silane on the nanoscale. The revealed mechanism can be further used to help the development of high-performance composite coatings.

9.
ACS Omega ; 8(18): 16016-16031, 2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37179597

RESUMO

The application of silane in sulfoaluminate cement repair materials can improve its waterproof, permeability, freeze-thaw, and other properties, but it would reduce the mechanical properties of sulfoaluminate cement-based materials, making it unable to better meet the engineering requirements and durability indices. The modification of silane with graphene oxide (GO) can effectively address this issue. However, the failure mechanism of the interface between silane and sulfoaluminate cement-based materials and the modification mechanism of GO remain unclear. In this paper, the interface-bonding mechanical models of isobutyltriethoxysilane (IBTS)/ettringite and GO-IBTS/ettringite are established by molecular dynamics method to study the source of interface-bonding properties of IBTS, GO-IBTS, and ettringite, as well as the failure mechanism of interface bonding, to reveal the mechanism of GO-modifying IBTS to improve the interface-bonding properties of IBTS and ettringite. This study finds that the bonding properties of the IBTS, GO-IBTS, and ettringite interface are derived from the amphiphilic nature of IBTS, which can only produce unilateral bonding with ettringite, thus becoming a weak link in interface dissociation. The double-sided nature of GO functional groups enables GO-IBTS to interact well with bilateral ettringite, thus enhancing the interface-bonding properties.

10.
Materials (Basel) ; 16(7)2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-37049207

RESUMO

Layered double hydroxides (LDHs) intercalating with a corrosion inhibitor for slowing down the corrosion of a reinforcing bar has attracted considerable attention. However, achieving high-loading capacity of organic inhibitor in LDH with high efficiency and long-term protection characteristics remains an important challenge. In this work, the CaAl-LDH intercalating with eugenol (EG) was synthesized via a continuous hydrothermal method. The prepared LDHs were characterized by SEM, XRD, UV-vis absorption spectra and TGA. Additionally, the corrosion protection performances of LDH-EG for steel bar were studied in detail via the electrochemical method. The results show that the loading amount of EG in LDHs was about 30% and about 80% EG could be released from LDH-EG within 4 h in SCPs containing 3.5% NaCl. The electrochemical test results show that the Rct value (105~106 Ω · cm2) of steel-mortar incorporated with LDH-EG has increased by 3-4 orders of magnitude compared to the specimen without LDHs (102~103 Ω · cm2) after 16 dry-wet cycles corrosion test. The significantly improved protection capability is mainly derived from two aspects: one is the filling effect of LDH, which can fill the pores of mortar and improve the impermeability; another reason is that the intercalated EG can slowly diffuse out of the inner structure of LDHs in a controllable way and result in a relatively long-term effect of corrosion inhibition.

11.
Sci Bull (Beijing) ; 68(10): 990-997, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37100643

RESUMO

The itinerant ferromagnetism can be induced by a van Hove singularity (VHS) with a divergent density of states at Fermi level. Utilizing the giant magnified dielectric constant εr of SrTiO3(111) substrate with cooling, here we successfully manipulated the VHS in the epitaxial monolayer (ML) 1T-VSe2 film approaching to Fermi level via the large interfacial charge transfer, and thus induced a two-dimensional (2D) itinerant ferromagnetic state below 3.3 K. Combining the direct characterization of the VHS structure via angle-resolved photoemission spectroscopy (ARPES), together with the theoretical analysis, we ascribe the manipulation of VHS to the physical origin of the itinerant ferromagnetic state in ML 1T-VSe2. Therefore, we further demonstrated that the ferromagnetic state in the 2D system can be controlled through manipulating the VHS by engineering the film thickness or replacing the substrate. Our findings clearly evidence that the VHS can serve as an effective manipulating degree of freedom for the itinerant ferromagnetic state, expanding the application potentials of 2D magnets for the next-generation information technology.


Assuntos
Asma , Doença Pulmonar Obstrutiva Crônica , Humanos , Imãs , Temperatura Baixa
12.
Phys Rev Lett ; 131(25): 256002, 2023 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-38181352

RESUMO

The Fe_{4}Se_{5} with a sqrt[5]×sqrt[5] Fe vacancy order is suggested to be a Mott insulator and the parent state of bulk FeSe superconductor. The iron vacancy ordered state has been considered as a Mott insulator and the parent compound of bulk FeSe-based superconductors. However, for the superconducting FeSe/SrTiO_{3} monolayer (FeSe/STO) with an interface-enhanced high transition temperature (T_{c}), the electronic evolution from its Fe vacancy ordered parent phase to the superconducting state, has not been explored due to the challenge to realize an Fe vacancy order in the FeSe/STO monolayer, even though important to the understanding of superconductivity mechanism. In this study, we developed a new method to generate Fe vacancies within the FeSe/STO monolayer in a tunable fashion, with the assistance of atomic hydrogen. As a consequence, an insulating sqrt[5]×sqrt[5] Fe vacancy ordered monolayer is realized as the parent state. By using scanning tunneling microscopy and scanning tunneling spectroscopy, the spectral evolution from superconductivity to insulator is fully characterized. Surprisingly, a prominent spectral weight transfer occurs, thus implying a strong electron correlation effect. Moreover, the Fe vacancy induced insulating gap exhibits no Mott gap-like features. This work provides new insights in understanding the high-T_{c} superconductivity in FeSe/STO monolayer.

13.
ACS Appl Mater Interfaces ; 14(35): 40297-40312, 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36002909

RESUMO

The construction of multiple microstructures is a significant measure in improving the protective performance of composite polymer coatings. In this paper, a novel polystyrene acrylate-highly hydrophobic polysiloxane composite emulsion was fabricated by innovatively integrating the core-shell emulsion method and Pickering emulsion method through the interfacial stabilization and molecular polymerization regulation of graphene oxide, achieving a significant improvement in the compatibility of the thermoplastic core with a thermoset shell. The bonding degree between the polystyrene acrylate (PSA) component and the siloxane component is significantly improved in the synthesized composite emulsions, achieving the dual protection of the cementitious substrate with surface shielding and internal crystalline hydrophobicity. The capillary water absorption of the concrete treated with Pickering emulsions is reduced by over 98.3% with high hydrophobicity and low permeability. Meanwhile, the absolute ζ-potential and impedance of composite membranes reach over 45 mV and 109 ohms, respectively, giving the cementitious substrate excellent resistance to ionic attack and acid/alkaline corrosion. In addition, the composite membranes have excellent resistance to tensile cracking and physical erosion, maintaining a favorable adhesion level and plastic deformation under acid/alkaline attack and thermal aging, respectively.

14.
Artigo em Inglês | MEDLINE | ID: mdl-35805721

RESUMO

Monitoring the fine spatiotemporal distribution of urban GDP is a critical research topic for assessing the impact of the COVID-19 outbreak on economic and social growth. Based on nighttime light (NTL) images and urban land use data, this study constructs a GDP machine learning and linear estimation model. Based on the linear model with better effect, the monthly GDP of 34 cities in China is estimated and the GDP spatialization is realized, and finally the GDP spatiotemporal correction is processed. This study analyzes the fine spatiotemporal distribution of GDP, reveals the spatiotemporal change trend of GDP in China's major cities during the current COVID-19 pandemic, and explores the differences in the economic impact of the COVID-19 pandemic on China's major cities. The result shows: (1) There is a significant linear association between the total value of NTL and the GDP of subindustries, with R2 models generated by the total value of NTL and the GDP of secondary and tertiary industries being 0.83 and 0.93. (2) The impact of the COVID-19 pandemic on the GDP of cities with varied degrees of development and industrial structures obviously varies across time and space. The GDP of economically developed cities such as Beijing and Shanghai are more affected by COVID-19, while the GDP of less developed cities such as Xining and Lanzhou are less affected by COVID-19. The GDP of China's major cities fell significantly in February. As the COVID-19 outbreak was gradually brought under control in March, different cities achieved different levels of GDP recovery. This study establishes a fine spatial and temporal distribution estimation model of urban GDP by industry; it accurately monitors and assesses the spatial and temporal distribution characteristics of urban GDP during the COVID-19 pandemic, reveals the impact mechanism of the COVID-19 pandemic on the economic development of major Chinese cities. Moreover, economically developed cities should pay more attention to the spread of the COVID-19 pandemic. It should do well in pandemic prevention and control in airports and stations with large traffic flow. At the same time, after the COVID-19 pandemic is brought under control, they should speed up the resumption of work and production to achieve economic recovery. This study provides scientific references for COVID-19 pandemic prevention and control measures, as well as for the formulation of urban economic development policies.


Assuntos
COVID-19 , COVID-19/epidemiologia , China/epidemiologia , Cidades/epidemiologia , Humanos , Pandemias , Urbanização
15.
Cancer Manag Res ; 14: 1795-1806, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35637941

RESUMO

Purpose: The fibrinogen/albumin ratio (FAR) is increasingly considered as a potential biomarker for predicting prognosis in various malignant tumors, whereas the value of the FAR in predicting the recurrence-free survival (RFS) in patients with combined hepatocellular cholangiocarcinoma (cHCC-CCA) after surgery has not been studied. Patients and Methods: A total of 104 patients with surgical-pathologically proved cHCC-CCA were retrospectively analyzed. The best cut-off value of the FAR was calculated via receiver operating characteristic (ROC) curve analysis, and the cohort was then divided into two groups as high-FAR (H-FAR) group and low-FAR (L-FAR) group. The correlation between the preoperative FAR and clinicopathological characteristics was analyzed. Uni- and multi-variable analyses for RFS were evaluated using a Cox proportional hazards model to verify the predictive value of FAR on the RFS of cHCC-CCA. Additionally, a novel clinical nomogram based on FAR was developed to preoperatively predict the RFS of HCC-CCA. The C-index and calibration were conducted to evaluate the performance of the developed nomogram. Results: According to the cut-off value of the FAR, the patients were grouped into the H-FARI (>0.075) and L-FARI (≤0.075) groups. FAR was significantly correlated with several clinical-pathological features, including age, cirrhosis, AFP, CA19-9, BCLC staging, NLR, and PLR. In the multi-variate analysis, FAR, cirrhosis and tumor size were independent prognostic predictors for poor RFS in cHCC-CCA patients after surgery. Moreover, the clinical nomogram based on FAR was constructed, showing well-predictive accuracy. Conclusion: The preoperative FAR is a convenient and feasible serum biomarker for predicting the RFS of cHCC-CCA after surgery. Such developed FAR-based nomogram integrating tumor size and cirrhosis could be served as a feasible and convenient tool to assist the decision-making of clinical strategy.

16.
Artigo em Inglês | MEDLINE | ID: mdl-35409987

RESUMO

Rapid economic and social development has caused serious atmospheric environmental problems. The temporal and spatial distribution characteristics of PM2.5 concentrations have become an important research topic for sustainable social development monitoring. Based on NPP-VIIRS nighttime light images, meteorological data, and SRTM DEM data, this article builds a PM2.5 concentration estimation model for the Chang-Zhu-Tan urban agglomeration. First, the partial least squares method is used to calculate the nighttime light radiance, meteorological elements (temperature, relative humidity, and wind speed), and topographic elements (elevation, slope, and topographic undulation) for correlation analysis. Second, we construct seasonal and annual PM2.5 concentration estimation models, including multiple linear regression, support random forest, vector regression, Gaussian process regression, etc., with different factor sets. Finally, the accuracy of the PM2.5 concentration estimation model that results in the Chang-Zhu-Tan urban agglomeration is analyzed, and the spatial distribution of the PM2.5 concentration is inverted. The results show that the PM2.5 concentration correlation of meteorological elements is the strongest, and the topographic elements are the weakest. In terms of seasonal estimation, the spring estimation results of multiple linear regression and machine learning estimation models are the worst, the winter estimation results of multiple linear regression estimation models are the best, and the annual estimation results of machine learning estimation models are the best. At the same time, the study found that there is a significant difference in the temporal and spatial distribution of PM2.5 concentrations. The methods in this article overcome the high cost and spatial resolution limitations of traditional large-scale PM2.5 concentration monitoring, to a certain extent, and can provide a reference for the study of PM2.5 concentration estimation and prediction based on satellite remote sensing technology.

17.
Nat Mater ; 21(3): 284-289, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34916657

RESUMO

Nanoscale periodic moiré patterns, for example those formed at the interface of a twisted bilayer of two-dimensional materials, provide opportunities for engineering the electronic properties of van der Waals heterostructures1-11. In this work, we synthesized the epitaxial heterostructure of 1T-TiTe2/1T-TiSe2 with various twist angles using molecular beam epitaxy and investigated the moiré pattern induced/enhanced charge density wave (CDW) states with scanning tunnelling microscopy. When the twist angle is near zero degrees, 2 × 2 CDW domains are formed in 1T-TiTe2, separated by 1 × 1 normal state domains, and trapped in the moiré pattern. The formation of the moiré-trapped CDW state is ascribed to the local strain variation due to atomic reconstruction. Furthermore, this CDW state persists at room temperature, suggesting its potential for future CDW-based applications. Such moiré-trapped CDW patterns were not observed at larger twist angles. Our study paves the way for constructing metallic twist van der Waals bilayers and tuning many-body effects via moiré engineering.

18.
Adv Mater ; 34(6): e2107799, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34818689

RESUMO

The superconducting proximity effect (SPE) induces a superconductivity transition in otherwise non-superconducting thin films in proximity with a superconductor. The SPE usually occurs in real space and decays exponentially with film thickness. Herein, an abnormal SPE in a topological insulator (TI)/superconductor heterostructure is unveiled, which is attributed to the topologically protected surface state. Surprisingly, such abnormal SPE occurs in momentum space regardless of the TI film thickness, as long as the topological surface states are robust and form a continuous conduction loop. Combining transport measurements and scanning tunneling microscopy/spectroscopy techniques, the SPE in Bi2 Se3 /FeSe0.5 Te0.5 heterostructures is explored, where Bi2 Se3 is an ideal 3D topological insulator and FeSe0.5 Te0.5 a typical iron-based superconductor. As the thickness of the Bi2 Se3 thin film exceeds 400 nm, there still exists SPE-induced superconductivity on the surface of Bi2 Se3 thin film with a transition temperature Tc not less than 10 K. Such an extraordinary behavior is induced by the unique properties of topologically protected surface states of Bi2 Se3 . This research deepens the understanding of the important role of topologically protected surface states in the SPE.

19.
Sensors (Basel) ; 21(21)2021 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-34770701

RESUMO

Rapid and accurate extraction of water bodies from high-spatial-resolution remote sensing images is of great value for water resource management, water quality monitoring and natural disaster emergency response. For traditional water body extraction methods, it is difficult to select image texture and features, the shadows of buildings and other ground objects are in the same spectrum as water bodies, the existing deep convolutional neural network is difficult to train, the consumption of computing resources is large, and the methods cannot meet real-time requirements. In this paper, a water body extraction method based on lightweight MobileNetV2 is proposed and applied to multisensor high-resolution remote sensing images, such as GF-2, WorldView-2 and UAV orthoimages. This method was validated in two typical complex geographical scenes: water bodies for farmland irrigation, which have a broken shape and long and narrow area and are surrounded by many buildings in towns and villages; and water bodies in mountainous areas, which have undulating topography, vegetation coverage and mountain shadows all over. The results were compared with those of the support vector machine, random forest and U-Net models and also verified by generalization tests and the influence of spatial resolution changes. First, the results show that the F1-score and Kappa coefficients of the MobileNetV2 model extracting water bodies from three different high-resolution images were 0.75 and 0.72 for GF-2, 0.86 and 0.85 for Worldview-2 and 0.98 and 0.98 for UAV, respectively, which are higher than those of traditional machine learning models and U-Net. Second, the training time, number of parameters and calculation amount of the MobileNetV2 model were much lower than those of the U-Net model, which greatly improves the water body extraction efficiency. Third, in other more complex surface areas, the MobileNetV2 model still maintained relatively high accuracy of water body extraction. Finally, we tested the effects of multisensor models and found that training with lower and higher spatial resolution images combined can be beneficial, but that using just lower resolution imagery is ineffective. This study provides a reference for the efficient automation of water body classification and extraction under complex geographical environment conditions and can be extended to water resource investigation, management and planning.


Assuntos
Redes Neurais de Computação , Tecnologia de Sensoriamento Remoto , Geografia , Aprendizado de Máquina , Máquina de Vetores de Suporte
20.
Epilepsia ; 62(11): 2707-2718, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34510448

RESUMO

OBJECTIVE: This study was undertaken to determine whether the vertical parasagittal approach or the lateral peri-insular/peri-Sylvian approach to hemispheric surgery is the superior technique in achieving long-term seizure freedom. METHODS: We conducted a post hoc subgroup analysis of the HOPS (Hemispheric Surgery Outcome Prediction Scale) study, an international, multicenter, retrospective cohort study that identified predictors of seizure freedom through logistic regression modeling. Only patients undergoing vertical parasagittal, lateral peri-insular/peri-Sylvian, or lateral trans-Sylvian hemispherotomy were included in this post hoc analysis. Differences in seizure freedom rates were assessed using a time-to-event method and calculated using the Kaplan-Meier survival method. RESULTS: Data for 672 participants across 23 centers were collected on the specific hemispherotomy approach. Of these, 72 (10.7%) underwent vertical parasagittal hemispherotomy and 600 (89.3%) underwent lateral peri-insular/peri-Sylvian or trans-Sylvian hemispherotomy. Seizure freedom was obtained in 62.4% (95% confidence interval [CI] = 53.5%-70.2%) of the entire cohort at 10-year follow-up. Seizure freedom was 88.8% (95% CI = 78.9%-94.3%) at 1-year follow-up and persisted at 85.5% (95% CI = 74.7%-92.0%) across 5- and 10-year follow-up in the vertical subgroup. In contrast, seizure freedom decreased from 89.2% (95% CI = 86.3%-91.5%) at 1-year to 72.1% (95% CI = 66.9%-76.7%) at 5-year to 57.2% (95% CI = 46.6%-66.4%) at 10-year follow-up for the lateral subgroup. Log-rank test found that vertical hemispherotomy was associated with durable seizure-free progression compared to the lateral approach (p = .01). Patients undergoing the lateral hemispherotomy technique had a shorter time-to-seizure recurrence (hazard ratio = 2.56, 95% CI = 1.08-6.04, p = .03) and increased seizure recurrence odds (odds ratio = 3.67, 95% CI = 1.05-12.86, p = .04) compared to those undergoing the vertical hemispherotomy technique. SIGNIFICANCE: This pilot study demonstrated more durable seizure freedom of the vertical technique compared to lateral hemispherotomy techniques. Further studies, such as prospective expertise-based observational studies or a randomized clinical trial, are required to determine whether a vertical approach to hemispheric surgery provides superior long-term seizure outcomes.


Assuntos
Epilepsia Resistente a Medicamentos , Epilepsia , Hemisferectomia , Criança , Epilepsia Resistente a Medicamentos/cirurgia , Epilepsia/cirurgia , Hemisferectomia/métodos , Humanos , Projetos Piloto , Estudos Prospectivos , Estudos Retrospectivos , Convulsões/cirurgia , Resultado do Tratamento
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