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1.
Sensors (Basel) ; 24(3)2024 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-38339723

RESUMO

Accurately extracting pixel-level buildings from high-resolution remote sensing images is significant for various geographical information applications. Influenced by different natural, cultural, and social development levels, buildings may vary in shape and distribution, making it difficult for the network to maintain a stable segmentation effect of buildings in different areas of the image. In addition, the complex spectra of features in remote sensing images can affect the extracted details of multi-scale buildings in different ways. To this end, this study selects parts of Xi'an City, Shaanxi Province, China, as the study area. A parallel encoded building extraction network (MARS-Net) incorporating multiple attention mechanisms is proposed. MARS-Net builds its parallel encoder through DCNN and transformer to take advantage of their extraction of local and global features. According to the different depth positions of the network, coordinate attention (CA) and convolutional block attention module (CBAM) are introduced to bridge the encoder and decoder to retain richer spatial and semantic information during the encoding process, and adding the dense atrous spatial pyramid pooling (DenseASPP) captures multi-scale contextual information during the upsampling of the layers of the decoder. In addition, a spectral information enhancement module (SIEM) is designed in this study. SIEM further enhances building segmentation by blending and enhancing multi-band building information with relationships between bands. The experimental results show that MARS-Net performs better extraction results and obtains more effective enhancement after adding SIEM. The IoU on the self-built Xi'an and WHU building datasets are 87.53% and 89.62%, respectively, while the respective F1 scores are 93.34% and 94.52%.

2.
Chinese Journal of School Health ; (12): 1902-1906, 2023.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-1004916

RESUMO

Objective@#To understand the knowledge of disinfection and its influencing factors among caregivers in childcare centers in Huangpu District, Shanghai, in order to provide a basis for the future development of targeted training programs and the work plan to enhance the professional level of disinfection practitioners in childcare centers.@*Methods@#A total of 423 caregivers from 62 childcare centers (including nursery schools) in Huangpu District were selected for a questionnaire about disinfection knowledge, influencing factors, and training needs in March 2023. Differences in disinfection knowledge among subjects with different characteristics were compared using χ 2 tests, and influencing factors were analyzed using a multi factor binary Logistic regression model.@*Results@#The overall knowledge rate of disinfection among caregivers was 50.12%, and those in public kindergartens, private ones, and nursery schools were 51.35%, 46.18%, and 42.57%, respectively, with statistically significant differences ( χ 2=14.25, P < 0.05 ). The caregivers in the highest level kindergartens ( OR =4.50, 95% CI =1.97-10.29), in first level ones ( OR =4.29, 95% CI = 1.98-9.33), in the institutions had clusters of outbreaks ( OR =1.87, 95% CI =1.14-3.07), in which the number of children to caregivers ratio being less than 10∶1 ( OR =21.81, 95% CI =2.55-186.59), with 6-14 years of working experience ( OR =3.51, 95% CI = 1.59 -7.75) had better knowledge of disinfection( P <0.05).@*Conclusions@#Knowledge of disinfection among caregivers of childcare institutions is low in Huangpu District, Shanghai. Training of caregivers disinfection knowledge should be strengthened for caregivers with fewer years of experience, in childcare institutions, to improve caregivers disinfection expertise and skills.

3.
Angew Chem Int Ed Engl ; 60(15): 8488-8493, 2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33369828

RESUMO

The first highly enantioselective CuI -catalyzed azide-alkyne cycloaddition (CuAAC) of tertiary alcohols and their kinetic resolution is reported. This approach allows facile access to multifunctional tertiary alcohols featuring an α-ethynyl or α-triazole moiety, and represents the first successful kinetic resolution of racemates with a tetrasubstituted carbon stereocenter via CuAAC. Newly developed pyridinebisoxazoline (PYBOX) ligands with a C4 phosphonate group play a key role.

4.
Chem Sci ; 11(1): 97-106, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-32110361

RESUMO

We report the highly enantioselective synthesis of P-chiral tertiary phosphine oxides featuring an ethynyl group via Cu(i)-catalyzed azide-alkyne cycloaddition. Newly developed chiral pyridinebisoxazolines (PYBOX) bearing a bulky C4 shielding group play an important role in achieving excellent enantioselectivity while suppressing side bis-triazoles formation in desymmetrizing prochiral diethynylphosphine oxides. Notably, by tuning the size of the C4 shielding group, it is possible to achieve excellent remote enantiofacial control in desymmetrizing phosphole oxide-diynes with the prochiral P-center farther from the ethynyl group by four covalent bonds. Time-dependent enantioselectivity is observed for these desymmetric CuAAC reactions, suggesting a synergic combination of a desymmetrization and a kinetic resolution, and our ligands prove to be better than unmodified PYBOX in both steps. This finding contributes to a highly enantioselective kinetic resolution of racemic ethynylphosphine oxides. The resulting chiral ethynylphosphine oxides are versatile P-chiral synthons, which can undergo a number of diversifying reactions to enrich structural diversity.

5.
Org Lett ; 22(4): 1270-1274, 2020 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-31999130

RESUMO

We report an unprecedented highly enantioselective desymmetric Cu(I)-catalyzed 1,3-dipolar cycloaddition of diazides with terminal alkynes and 1-iodoalkynes, affording tertiary alcohols bearing a 1,2,3-triazole moiety in high yield and excellent ee value. PYBOX ligands with a C4 shielding group once again show the promising ability to achieve higher enantioselectivity.

6.
BMC Infect Dis ; 17(1): 537, 2017 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-28774267

RESUMO

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) was first reported in China in 2011. Human-to-human transmission of the virus occurred occasionally in family clusters. However, pneumonia as an onset syndrome was not common in most SFTS cases. Our aim is to report a family cluster of SFTS with clinical manifestation of pneumonia in Shanghai. METHODS: Epidemiologic investigations were conducted when a family cluster of severe fever with thrombocytopenia syndrome virus (SFTSV) infection was identified in Shanghai in June 2016. Samples were collected from two secondary cases and two close contacts with fever. SFTSV was detected by Real-Time reverse transcription polymerase chain reaction (RT-PCR). RESULTS: There were two confirmed STFS cases and one potential index case. The potential index case became ill on 21 May and died on 31 May. Case A had onset from 4 to 23 June and case B from 8 June to 25 June. All the three cases experienced pneumonia at the early stage of SFTSV infection. Three (3) out of thirty two (32) close contacts had symptoms of fever or cough but were detected STFSV negative by real-time RT-PCR. According to epidemiologic investigations, the potential index case had outdoor activities on a nearby hill. A tick bite could have been the reason for the SFTSV infection in the potential index case as ticks were found both in grassland or shrubs on the hill and also found on mice caught in her house. Both cases A and B had provided bedside care for the potential index case without any protection and had contacted with blood and other body fluids. CONCLUSION: It was a family cluster of SFTSV infection imported from Jiangsu province located in the east of China. We suggested to become alert to atypical SFTSV infected cases.


Assuntos
Infecções por Bunyaviridae/epidemiologia , Phlebovirus/genética , Pneumonia Viral/epidemiologia , Trombocitopenia/epidemiologia , Idoso , Animais , Infecções por Bunyaviridae/tratamento farmacológico , Infecções por Bunyaviridae/etiologia , China/epidemiologia , Família , Feminino , Febre/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Phlebovirus/patogenicidade , Pneumonia Viral/virologia , Reação em Cadeia da Polimerase em Tempo Real , Trombocitopenia/virologia , Carrapatos/virologia
7.
Chem Commun (Camb) ; 51(59): 11798-801, 2015 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-26107929

RESUMO

A chemoselective [3+3] cycloaddition of in situ generated azomethine ylides with quinone monoimides has been established, which efficiently led to the construction of dihydrobenzoxazine frameworks with biological relevance, with excellent chemoselectivities and high yields (up to >95 : 5 cr and 98% yield).

8.
J Org Chem ; 80(1): 512-20, 2015 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-25479415

RESUMO

The first catalytic asymmetric 1,3-dipolar cycloadditions (1,3-DCs) of isatin-derived azomethine ylide with allenes have been established, which efficiently assembly isatins, amino-esters and 2,3-allenoate into enantioenriched spiro[indoline-3,2'-pyrrole] derivatives with a quaternary stereogenic center in generally high enantioselectivities (80-98% ee). In this allene-involved 1,3-DC, an unexpected spirooxindole framework bearing an intra-annular C═C double bond was generated, which is quite different from previously reported 1,3-DCs of allenes. This approach not only confronted the great challenge in using allenes as dipolarophiles of 1,3-DCs, but also provided a unique strategy of using allenes as equivalents of alkynes to construct spiro[indoline-3,2'-pyrrole] structure. Besides, this reaction also represents the first catalytic asymmetric ketone-involved 1,3-DCs of allenes, which will also greatly enrich the research contents of 1,3-DCs, the chemistry of allenes as well as the synthetic methods of spirooxindoles.


Assuntos
Alcadienos/química , Alcinos/química , Indóis/síntese química , Pirróis/síntese química , Catálise , Ciclização , Indóis/química , Estrutura Molecular , Pirróis/química , Estereoisomerismo
9.
J Org Chem ; 79(19): 9305-12, 2014 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-25207672

RESUMO

The first organocatalytic asymmetric inverse-electron-demand 1,3-dipolar cycloaddition (IED 1,3-DC) of N,N'-cyclic azomethine imines has been established in the presence of chiral phosphoric acid. This approach assembles N,N'-cyclic azomethine imines and o-hydroxystyrenes into chiral N,N-bicyclic pyrazolidin-3-one derivatives with the creation of two stereogenic centers, one of which is quaternary, in excellent diastereoselectivities and good enantioselectivities (up to >95:5 dr, 88:12 er). The investigation of the activation mode of the reaction revealed that the dual hydrogen-bonding interaction between the two substrates and the catalyst together with the conjugative effect initiated by the o-hydroxyl group played a crucial role in the designed IED 1,3-DC. This study will not only greatly enrich the underdeveloped research potential of catalytic asymmetric IED 1,3-DCs but will also facilitate the design of other enantioselective IED 1,3-DCs based on different activation modes.

10.
Chemistry ; 20(9): 2597-604, 2014 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-24488673

RESUMO

A catalytic asymmetric formal [3+3] cycloaddition of 3-indolylmethanol and an in situ-generated azomethine ylide has been established to construct a chiral six-membered piperidine framework with two stereogenic centers. This approach not only represents the first enantioselective cycloaddition of isatin-derived 3-indolylmethanol, but also has realized an unusual enantioselective formal [3+3] cycloaddition of azomethine ylide rather than its common [3+2] cycloadditions. Besides, this protocol combines the merits of a multicomponent reaction and organocatalysis, which efficiently assembles a variety of isatin-derived 3-indolylmethanols, aldehydes, and amino esters into structurally diverse spiro[indoline-3,4'-pyridoindoles] with one all-carbon quaternary stereogenic center in high yields and excellent enantioselectivities (up to 93 % yield, >99 % enantiomeric excess (ee)). Although the diastereoselectivity of the reaction is generally moderate, most of the diastereomers can be separated by using column chromatography followed by preparative TLC.

11.
Org Biomol Chem ; 11(9): 1482-9, 2013 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-23344919

RESUMO

A catalytic asymmetric construction of synthetically and biologically important 2,5-dihydropyrrole scaffolds with concomitant creation of multiple chiral carbon centers including one quaternary stereogenic center in high yields (up to 99%) and excellent enantioselectivities (up to 99% ee) has been established via an organocatalytic 1,3-dipolar cycloaddition using α-arylglycine esters as azomethine precursors. Moreover, a detailed investigation has been performed on the catalytic asymmetric 1,3-dipolar cycloadditions of α-arylglycine ester-generated azomethine ylides with alkynes, providing an efficient way to simultaneously access both 2,5-dihydropyrrole diastereomers in good enantioselectivities.


Assuntos
Ésteres/química , Glicina/química , Pirróis/química , Pirróis/síntese química , Catálise , Ciclização , Glicina/análogos & derivados , Estrutura Molecular , Estereoisomerismo
12.
Org Lett ; 15(1): 128-31, 2013 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-23240812

RESUMO

The first catalytic asymmetric isatin-involved Povarov reaction has been established. This method provides an unprecedented approach to access the enantioenriched spiro[indolin-3,2'-quinoline] scaffold with concomitant creation of two quaternary stereogenic centers in high yields and excellent stereoselectivities (all >99:1 dr's, up to 97% ee).

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