Spectrogram representations of acoustic scenes have achieved competitive performance for acoustic scene classification. Yet, the spectrogram alone does not take into account a substantial amount of time-frequency info...Spectrogram representations of acoustic scenes have achieved competitive performance for acoustic scene classification. Yet, the spectrogram alone does not take into account a substantial amount of time-frequency information. In this study, we present an approach for exploring the benefits of deep scalogram representations, extracted in segments from an audio stream. The approach presented firstly transforms the segmented acoustic scenes into bump and morse scalograms, as well as spectrograms; secondly, the spectrograms or scalograms are sent into pre-trained convolutional neural networks; thirdly,the features extracted from a subsequent fully connected layer are fed into(bidirectional) gated recurrent neural networks, which are followed by a single highway layer and a softmax layer;finally, predictions from these three systems are fused by a margin sampling value strategy. We then evaluate the proposed approach using the acoustic scene classification data set of 2017 IEEE AASP Challenge on Detection and Classification of Acoustic Scenes and Events(DCASE). On the evaluation set, an accuracy of 64.0 % from bidirectional gated recurrent neural networks is obtained when fusing the spectrogram and the bump scalogram, which is an improvement on the 61.0 % baseline result provided by the DCASE 2017 organisers. This result shows that extracted bump scalograms are capable of improving the classification accuracy,when fusing with a spectrogram-based system.展开更多
With the increasingly stringent standards for limiting sulfide content in liquid fuels,oxidative desulfurization(ODS)has become a promising ultra-deep desulfurization process in fuel desulfurization.TS-1 zeolites show...With the increasingly stringent standards for limiting sulfide content in liquid fuels,oxidative desulfurization(ODS)has become a promising ultra-deep desulfurization process in fuel desulfurization.TS-1 zeolites show great potential as catalysts for ODS reactions,due to its remarkable oxidation activity at low temperatures and pressure.However,the inherent microporous structure of conventional TS-1 zeolites restricts the mass transportation and renders the active sites in the microporous space of TS-1 zeolites inaccessible for bulky aromatic organosulfur compounds.Fabrication of hierarchical TS-1 zeolites by incorporating meso-/macropores into microporous TS-1 zeolites is an effective strategy to improve mass transportability.In recent years,abundant efforts have been dedicated to developing synthetic strategies of hierarchical TS-1 zeolite,thereby improving its catalytic performance in the ODS process.This mini-review addresses the synthetic methods of hierarchical TS-1 catalysts and their catalytic performance in the ODS reactions.In addition,some current problems and prospects of synthesis routes for constructing hierarchical TS-1 catalysts have also been revised.We expect this mini-review to shed light on the more efficient preparation strategies of hierarchical TS-1 zeolites for the ODS process.展开更多
Macroscopic SiO2 spheres with a homogeneous amine distribution were synthesized by a one-step emulsion based synthesis approach in a flow column reactor. The CO2 adsorption capacity of the nanostructured amine-functio...Macroscopic SiO2 spheres with a homogeneous amine distribution were synthesized by a one-step emulsion based synthesis approach in a flow column reactor. The CO2 adsorption capacity of the nanostructured amine-functionalized silica spheres was studied in absence and presence of H2O. The structural properties were adjusted by varying solvents and surfactants during the synthesis and, at constant amine loadings, were found to be the main factor for influencing the CO2 sorption capacities. Under water-free conditions CO2 is bound to the amino groups via the formation of carbamates, which require two neighboring amino groups to adsorb one CO2 molecule. At constant amine concentrations sorbents with lower surface area allow to establish a higher amine density on the surface, which enhances the CO2 uptake capacities under dry conditions. In presence of H2O the CO2 adsorption changes to 1：1 stoichiometry due to stabilization of carbamates by protonation of H2O and formation of further species such as bicarbonates, which should in principle double the adsorption capacities. Low concentrations of physisorbed H2O（0.3 mmol/g） did not impair the adsorption capacity of the adsorbents for CO2, while at higher water uptakes（0.6 and 1.1 mmol/g） the CO2 uptake is reduced, which could be attributed to capillary condensation of H2O or formation of bulky reaction products blocking inner pores and access to active sites.展开更多
Epiphytic plant species are an important part of biological diversity. It is therefore essential to understand the distribution pattern and the factors influencing such patterns. The present study is aimed at observin...Epiphytic plant species are an important part of biological diversity. It is therefore essential to understand the distribution pattern and the factors influencing such patterns. The present study is aimed at observing the patterns of species richness, abundances and species composition of epiphytic orchids and ferns in two subtropical forests in Nepal. We also studied the relationship of host plants(Schima wallichii and Quercus lanata) and epiphyte species. Data were collected in Naudhara community forest(CF) and the national forest(NF) in Shivapuri Nagarjun National Park. The data were analyzed using univariate and multivariate tests. In total, we recorded 41 species of epiphytes(33 orchid and 8 fern species). Orchid species abundance is significantlyhigher in CF compared to NF. Orchid species richness and abundance increased with increasing southern aspect whereas it decreased with increasing canopy cover, and fern species richness increased with host bark roughness. Orchid abundance was positively correlated with increasing bark p H, stem size, tree age and tree height and negatively correlated with increasing steepness of the area. Likewise, fern abundances were high in places with high canopy cover, trees that were tall and big, but decreased with increasing altitude and southern aspect. The composition of the orchid and fern species was affected by altitude, aspect, canopy cover, DBH, number of forks and forest management types. We showed that the diversity of orchid and fern epiphytes is influenced by host characteristics as well as host types. The most important pre-requisite for a high epiphyte biodiversity is the presence of oldrespectively tall trees, independent of the recent protection status. This means:(i) for protection, e.g.in the frame of the national park declaration, such areas should be used which host such old tall trees;and(ii) also in managed forests and even in intensively used landscapes epiphytes can be protected by letting a certain number of trees be and by giving them space to grow old and tall.展开更多
In our previous work [Phys. Lett. （to be published）, Chin. Phys. Lett. 23 （2006） 3226], we introduced a separable pairing force for relativistic Hartree-Bogoliubov calculations. This force was adjusted to reproduc...In our previous work [Phys. Lett. （to be published）, Chin. Phys. Lett. 23 （2006） 3226], we introduced a separable pairing force for relativistic Hartree-Bogoliubov calculations. This force was adjusted to reproduce the pairing properties of the Gogny force in nuclear matter. By using the well known techniques of Talmi and Moshinsky it can be expanded in a series of separable terms and converges quickly after a few terms. It was found that the pairing properties can be depicted on almost the same footing as the original pairing interaction, not only in nuclear matter, but also in finite nuclei. In this study, we construct a relativistic quasiparticle random phase approximation （RQRPA） with this separable pairing interaction and calculate the excitation energies of the first excited 2^＋ states and reduced B（E2; 0^＋ → 2^＋） transition rates for a chain of Sn isotopes in RQRPA. Compared with the results of the full Gogny force, we find that this simple separable pairing interaction can describe the pairing properties of the excited vibrational states as well as the original pairing interaction.展开更多
The past few decades have witnessed a great endeavor in the search for quantum spin liquids(QSLs).;This phase of matter,which features long-ranged quantum entanglement and fractionalized spin excitations,is beyond Lan...The past few decades have witnessed a great endeavor in the search for quantum spin liquids(QSLs).;This phase of matter,which features long-ranged quantum entanglement and fractionalized spin excitations,is beyond Landau’s symmetrybreaking paradigm and is naturally associated with the celebrated idea of resonating valence bond(RVB).;What is more,high-temperature superconductivity was proposed to emerge from doping such an RVB state.展开更多
The authors investigated the PRNP Met129Val polymorphismin 1,393 subjects including 482 patients with Alzheimer disease (AD) and two independent control groups. In patients, PRNP Met homozygosity conferred increasing ...The authors investigated the PRNP Met129Val polymorphismin 1,393 subjects including 482 patients with Alzheimer disease (AD) and two independent control groups. In patients, PRNP Met homozygosity conferred increasing risk with decreasing age at onset (onset: 61 to 70 years, n=151, p=0.02, odds ratio =1.72, 95% CI=1.2 to 2.53; onset: ≤ 60 years, n=138, p = 0.013, OR=1.92, 95% CI=1.31 to 2.87), whereas no association was obtained in patients with onset at older than 70 years. The results suggest involvement of the prion protein in the pathogenesis of early onset AD.展开更多
Fruit production and especially fresh tropical fruit trade, has an important relevance on world economy. Refining knowledge on virus diseases affecting tropical fruits is required to improve the understanding of these...Fruit production and especially fresh tropical fruit trade, has an important relevance on world economy. Refining knowledge on virus diseases affecting tropical fruits is required to improve the understanding of these diseases, their dynamics and consequently, the ability to manage them. In this paper, samples of “uchuva” plants (Physalis peruviana L.) obtained from Centro Agropecuario Marengo (CAM) Municipality of Mosquera, Cundinamarca region of Colombia were analyzed after expressing symptoms of leaf chlorosis, leaf malformation, mosaic patterns and dwarfing. Electron microscopy revealed the presence of two different viral particles congruent with Potyvirus and Tobamovirus genus morphology. The presence of Potyvirus affecting the P. peruviana L. culture was confirmed in the samples analyzed by means of electronic microscopy images and serology. Similarly, the existence of viral particles with coherent characteristics of a putative Tobamovirus was observed. However, its presence could not be confirmed by means of serological tests. Nevertheless, its incidence should not be neglected. The mechanism of Potyvirus disease transmission in P. peruviana L. remains unknown, as well as the vectors associated with this disease. Therefore, complementary work and research should be considered. In addition to serology and electron microscopy, the use of indicator plants for diagnosis is suggested. Finally, a complete molecular characterization of the Potyvirus is recommended for a better understanding of the characteristics of its association with P. peruviana L.展开更多
Background The number of pediatric cases of infection with the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)Omicron variant has increased.Here,we describe the clinical characteristics of children in a te...Background The number of pediatric cases of infection with the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)Omicron variant has increased.Here,we describe the clinical characteristics of children in a tertiary children's medical center in Shanghai.Methods A total of 676 pediatric coronavirus disease 2019(COVID-19)cases caused by the Omicron variant who were admitted to the Shanghai Children's Medical Center from March 28 to April 30,2022 were enrolled in this single-center,prospective,observational real-world study.Patient demographics and clinical characteristics,especially COVID-19 vaccine status,were assessed.Results Children of all ages appeared susceptible to the SARS-CoV-2 Omicron variant,with no significant difference between sexes.A high SARS-CoV-2 viral load upon admission was associated with leukocytopenia,neutropenia,and thrombocytopenia(P=0.003,P=0.021,and P=0.017,respectively)but not with physical symptoms or radiographic chest abnormalities.Univariable linear regression models indicated that comorbidities(P=0.001)were associated with a longer time until viral clearance,and increasing age(P<0.001)and two doses of COVID-19 vaccine(P=0.001)were associated with a shorter time to viral clearance.Multivariable analysis revealed an independent effect of comorbidities(P<0.001)and age(P=0.003).The interaction effect between age and comorbidity showed that the negative association between age and time to virus clearance remained significant only in patients without underlying diseases(P<0.001).Conclusion This study describes the clinical characteristics of children infected with the Omicron variant of SARS-CoV-2 and calls for additional studies to evaluate the effectiveness and safety of vaccination against COVID-19 in children.展开更多
Plants emit an overabundance of volatile compounds, which act in their producers either as appreciated attractants to lure beneficial animals or as repellent toxins to deter pests in a species-specific and concentrati...Plants emit an overabundance of volatile compounds, which act in their producers either as appreciated attractants to lure beneficial animals or as repellent toxins to deter pests in a species-specific and concentration-dependent manner. Plants have evolved solutions to provide sufficient volatiles without poisoning themselves. Uridine-diphosphate sugar-dependent glycosyltransferases （UGTs） acting on vola-tiles is one important part of this sophisticated system, which balances the levels of bioactive metabolites and prepares them for cellular and long-distance transport and storage but enables the remobilization of disarmed toxins for the benefit of plant protection. This review provides an overview of the research history of glycosidically bound volatiles （GBVs）, a relatively new group of plant secondary metabolites, and discusses the role of UGTs in the production of GBVs for plant protection.展开更多
Liver sinusoidal endothelial cells （LSECs） line the liver sinusoids and separate passenger leukocytes in the sinusoidal lumen from hepatocytes. LSECs further act as a platform for adhesion of various liver-resident ...Liver sinusoidal endothelial cells （LSECs） line the liver sinusoids and separate passenger leukocytes in the sinusoidal lumen from hepatocytes. LSECs further act as a platform for adhesion of various liver-resident immune cell populations such as Kupffer cells, innate lymphoid cells or liver dendritic cells. In addition to having an extraordinary scavenger function, LSECs possess potent immune functions, serving as sentinel cells to detect microbial infection through pattern recognition receptor activation and as antigen （cross）-presenting cells. LSECs cross-prime naive CD8 T cells, causing their rapid differentiation into memory T cells that relocate to secondary lymphoid tissues and provide protection when they re-encounter the antigen during microbial infection. Cross-presentation of viral antigens by LSECs derived from infected hepatocytes triggers local activation of effector CD8 T cells and thereby assures hepatic immune surveillance. The immune function of LSECs complements conventional immune-activating mechanisms to accommodate optimal immune surveillance against infectious microorganisms while preserving the integrity of the liver as a metabolic organ.展开更多
The effects of welding speed on the macroscopic and microscopic residual stresses(RSes) in friction stir welded 17 vol.% SiCp/2009 Al-T4 composite plates were studied via neutron diffraction and an improved decoupled ...The effects of welding speed on the macroscopic and microscopic residual stresses(RSes) in friction stir welded 17 vol.% SiCp/2009 Al-T4 composite plates were studied via neutron diffraction and an improved decoupled hierarchical multiscale modeling methods. Measurements showed that the macroscopic and total RSes had the largest variations in the longitudinal direction(LD). Increasing the welding speed led to higher values of measured LD macroscopic and total RSes in the matrix. The welding speed also significantly influenced the distributions and magnitudes of the microscopic RSes. The RSes were predicted via an improved hierarchical multiscale model, which includes a constant coefficient of friction based thermal model. The RSes in the composite plates before friction stir welding(FSW) were computed and then set as the initial states of the FSW process during modeling. This improved decoupled multiscale model provided improved predictions of the temperature and RSes compared with our previous model.展开更多
Originally developed for diagnostic ultrasound imaging,piezoelectric transducers are the most widespread technology employed in optoacoustic(photoacoustic)signal detection.However,the detection requirements of optoaco...Originally developed for diagnostic ultrasound imaging,piezoelectric transducers are the most widespread technology employed in optoacoustic(photoacoustic)signal detection.However,the detection requirements of optoacoustic sensing and imaging differ from those of conventional ultrasonography and lead to specifications not sufficiently addressed by piezoelectric detectors.Consequently,interest has shifted to utilizing entirely optical methods for measuring optoacoustic waves.All-optical sound detectors yield a higher signal-to-noise ratio per unit area than piezoelectric detectors and feature wide detection bandwidths that may be more appropriate for optoacoustic applications,enabling several biomedical or industrial applications.Additionally,optical sensing of sound is less sensitive to electromagnetic noise,making it appropriate for a greater spectrum of environments.In this review,we categorize different methods of optical ultrasound detection and discuss key technology trends geared towards the development of all-optical optoacoustic systems.We also review application areas that are enabled by all-optical sound detectors,including interventional imaging,non-contact measurements,magnetoacoustics,and nondestructive testing.展开更多
基金supported by the German National BMBF IKT2020-Grant(16SV7213)(EmotAsS)the European-Unions Horizon 2020 Research and Innovation Programme(688835)(DE-ENIGMA)the China Scholarship Council(CSC)
文摘Spectrogram representations of acoustic scenes have achieved competitive performance for acoustic scene classification. Yet, the spectrogram alone does not take into account a substantial amount of time-frequency information. In this study, we present an approach for exploring the benefits of deep scalogram representations, extracted in segments from an audio stream. The approach presented firstly transforms the segmented acoustic scenes into bump and morse scalograms, as well as spectrograms; secondly, the spectrograms or scalograms are sent into pre-trained convolutional neural networks; thirdly,the features extracted from a subsequent fully connected layer are fed into(bidirectional) gated recurrent neural networks, which are followed by a single highway layer and a softmax layer;finally, predictions from these three systems are fused by a margin sampling value strategy. We then evaluate the proposed approach using the acoustic scene classification data set of 2017 IEEE AASP Challenge on Detection and Classification of Acoustic Scenes and Events(DCASE). On the evaluation set, an accuracy of 64.0 % from bidirectional gated recurrent neural networks is obtained when fusing the spectrogram and the bump scalogram, which is an improvement on the 61.0 % baseline result provided by the DCASE 2017 organisers. This result shows that extracted bump scalograms are capable of improving the classification accuracy,when fusing with a spectrogram-based system.
基金supported by the National Natural Science Foundation of China(21971082)the Jilin Province Science and Technology Development Plan(20200201096JC and 20190201229JC)+1 种基金the China Postdoctoral Science Foundation(2019T120235 and 2018M640280)for supporting this workthe 111 Project(B17020)。
文摘With the increasingly stringent standards for limiting sulfide content in liquid fuels,oxidative desulfurization(ODS)has become a promising ultra-deep desulfurization process in fuel desulfurization.TS-1 zeolites show great potential as catalysts for ODS reactions,due to its remarkable oxidation activity at low temperatures and pressure.However,the inherent microporous structure of conventional TS-1 zeolites restricts the mass transportation and renders the active sites in the microporous space of TS-1 zeolites inaccessible for bulky aromatic organosulfur compounds.Fabrication of hierarchical TS-1 zeolites by incorporating meso-/macropores into microporous TS-1 zeolites is an effective strategy to improve mass transportability.In recent years,abundant efforts have been dedicated to developing synthetic strategies of hierarchical TS-1 zeolite,thereby improving its catalytic performance in the ODS process.This mini-review addresses the synthetic methods of hierarchical TS-1 catalysts and their catalytic performance in the ODS reactions.In addition,some current problems and prospects of synthesis routes for constructing hierarchical TS-1 catalysts have also been revised.We expect this mini-review to shed light on the more efficient preparation strategies of hierarchical TS-1 zeolites for the ODS process.
基金supported by the German Research Council(DFG)within the priority program(Schwerpunktprogramm),“Poröse Medien mit definierter Porenstruktur in der Verfahrenstechnik–Modellierung,Anwendngen,Synthese”(SPP 1570)under the projects LE 1187/10 and SP 648/4the framework of the DFG Excellence Initiative the Cluster of Excellence“Engineering of Advanced Materials”(DFG EXC 415)funding via the DFG research training group GRK 1896
文摘Macroscopic SiO2 spheres with a homogeneous amine distribution were synthesized by a one-step emulsion based synthesis approach in a flow column reactor. The CO2 adsorption capacity of the nanostructured amine-functionalized silica spheres was studied in absence and presence of H2O. The structural properties were adjusted by varying solvents and surfactants during the synthesis and, at constant amine loadings, were found to be the main factor for influencing the CO2 sorption capacities. Under water-free conditions CO2 is bound to the amino groups via the formation of carbamates, which require two neighboring amino groups to adsorb one CO2 molecule. At constant amine concentrations sorbents with lower surface area allow to establish a higher amine density on the surface, which enhances the CO2 uptake capacities under dry conditions. In presence of H2O the CO2 adsorption changes to 1：1 stoichiometry due to stabilization of carbamates by protonation of H2O and formation of further species such as bicarbonates, which should in principle double the adsorption capacities. Low concentrations of physisorbed H2O（0.3 mmol/g） did not impair the adsorption capacity of the adsorbents for CO2, while at higher water uptakes（0.6 and 1.1 mmol/g） the CO2 uptake is reduced, which could be attributed to capillary condensation of H2O or formation of bulky reaction products blocking inner pores and access to active sites.
基金“Bauer-Stiftung und Glaser-Stiftung im Stifterverband für die Deutsche Wissenschaft” Project No. T237/24905/2013/Kg for the research grantgrant number 14-36098G of the Czech Science Foundation and the institutional support RVO 67985939
文摘Epiphytic plant species are an important part of biological diversity. It is therefore essential to understand the distribution pattern and the factors influencing such patterns. The present study is aimed at observing the patterns of species richness, abundances and species composition of epiphytic orchids and ferns in two subtropical forests in Nepal. We also studied the relationship of host plants(Schima wallichii and Quercus lanata) and epiphyte species. Data were collected in Naudhara community forest(CF) and the national forest(NF) in Shivapuri Nagarjun National Park. The data were analyzed using univariate and multivariate tests. In total, we recorded 41 species of epiphytes(33 orchid and 8 fern species). Orchid species abundance is significantlyhigher in CF compared to NF. Orchid species richness and abundance increased with increasing southern aspect whereas it decreased with increasing canopy cover, and fern species richness increased with host bark roughness. Orchid abundance was positively correlated with increasing bark p H, stem size, tree age and tree height and negatively correlated with increasing steepness of the area. Likewise, fern abundances were high in places with high canopy cover, trees that were tall and big, but decreased with increasing altitude and southern aspect. The composition of the orchid and fern species was affected by altitude, aspect, canopy cover, DBH, number of forks and forest management types. We showed that the diversity of orchid and fern epiphytes is influenced by host characteristics as well as host types. The most important pre-requisite for a high epiphyte biodiversity is the presence of oldrespectively tall trees, independent of the recent protection status. This means:(i) for protection, e.g.in the frame of the national park declaration, such areas should be used which host such old tall trees;and(ii) also in managed forests and even in intensively used landscapes epiphytes can be protected by letting a certain number of trees be and by giving them space to grow old and tall.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10875150, 10775183 and 10535010, the National Basis Research Program of China under Grant No 2007CB815000, the Asia-Europe Link Project [CN/ASIA-LINK/008 （094-791）], the Bundesministerium fur Bildung und Forschung, Germany under Grant No 06MT246, and the DFG Cluster of Excellence ＂Origin and Structure of the Universe＂ （www.universe-cluster.de）.
文摘In our previous work [Phys. Lett. （to be published）, Chin. Phys. Lett. 23 （2006） 3226], we introduced a separable pairing force for relativistic Hartree-Bogoliubov calculations. This force was adjusted to reproduce the pairing properties of the Gogny force in nuclear matter. By using the well known techniques of Talmi and Moshinsky it can be expanded in a series of separable terms and converges quickly after a few terms. It was found that the pairing properties can be depicted on almost the same footing as the original pairing interaction, not only in nuclear matter, but also in finite nuclei. In this study, we construct a relativistic quasiparticle random phase approximation （RQRPA） with this separable pairing interaction and calculate the excitation energies of the first excited 2^＋ states and reduced B（E2; 0^＋ → 2^＋） transition rates for a chain of Sn isotopes in RQRPA. Compared with the results of the full Gogny force, we find that this simple separable pairing interaction can describe the pairing properties of the excited vibrational states as well as the original pairing interaction.
文摘The past few decades have witnessed a great endeavor in the search for quantum spin liquids(QSLs).;This phase of matter,which features long-ranged quantum entanglement and fractionalized spin excitations,is beyond Landau’s symmetrybreaking paradigm and is naturally associated with the celebrated idea of resonating valence bond(RVB).;What is more,high-temperature superconductivity was proposed to emerge from doping such an RVB state.
文摘The authors investigated the PRNP Met129Val polymorphismin 1,393 subjects including 482 patients with Alzheimer disease (AD) and two independent control groups. In patients, PRNP Met homozygosity conferred increasing risk with decreasing age at onset (onset: 61 to 70 years, n=151, p=0.02, odds ratio =1.72, 95% CI=1.2 to 2.53; onset: ≤ 60 years, n=138, p = 0.013, OR=1.92, 95% CI=1.31 to 2.87), whereas no association was obtained in patients with onset at older than 70 years. The results suggest involvement of the prion protein in the pathogenesis of early onset AD.
基金supported by the German Research Foundation(DFG)the Technische Universitat Munchen within the funding program Open Access Publishing.
文摘Fruit production and especially fresh tropical fruit trade, has an important relevance on world economy. Refining knowledge on virus diseases affecting tropical fruits is required to improve the understanding of these diseases, their dynamics and consequently, the ability to manage them. In this paper, samples of “uchuva” plants (Physalis peruviana L.) obtained from Centro Agropecuario Marengo (CAM) Municipality of Mosquera, Cundinamarca region of Colombia were analyzed after expressing symptoms of leaf chlorosis, leaf malformation, mosaic patterns and dwarfing. Electron microscopy revealed the presence of two different viral particles congruent with Potyvirus and Tobamovirus genus morphology. The presence of Potyvirus affecting the P. peruviana L. culture was confirmed in the samples analyzed by means of electronic microscopy images and serology. Similarly, the existence of viral particles with coherent characteristics of a putative Tobamovirus was observed. However, its presence could not be confirmed by means of serological tests. Nevertheless, its incidence should not be neglected. The mechanism of Potyvirus disease transmission in P. peruviana L. remains unknown, as well as the vectors associated with this disease. Therefore, complementary work and research should be considered. In addition to serology and electron microscopy, the use of indicator plants for diagnosis is suggested. Finally, a complete molecular characterization of the Potyvirus is recommended for a better understanding of the characteristics of its association with P. peruviana L.
基金This work was funded by the Innovative Research Team of High-Level Local Universities in Shanghai(SHSMUZDCX20212800)Science and Technology Commission Shanghai Municipality(20JC1410200,20JC1410204)+2 种基金2021 Shanghai University Teacher Training Plan-Industry University Research Practice Plan Project(EYJ26.RLO17)Shanghai Municipal Health Commission(2019SY049)Shanghai Medical Leading Talents Program(2019LJ22).
文摘Background The number of pediatric cases of infection with the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)Omicron variant has increased.Here,we describe the clinical characteristics of children in a tertiary children's medical center in Shanghai.Methods A total of 676 pediatric coronavirus disease 2019(COVID-19)cases caused by the Omicron variant who were admitted to the Shanghai Children's Medical Center from March 28 to April 30,2022 were enrolled in this single-center,prospective,observational real-world study.Patient demographics and clinical characteristics,especially COVID-19 vaccine status,were assessed.Results Children of all ages appeared susceptible to the SARS-CoV-2 Omicron variant,with no significant difference between sexes.A high SARS-CoV-2 viral load upon admission was associated with leukocytopenia,neutropenia,and thrombocytopenia(P=0.003,P=0.021,and P=0.017,respectively)but not with physical symptoms or radiographic chest abnormalities.Univariable linear regression models indicated that comorbidities(P=0.001)were associated with a longer time until viral clearance,and increasing age(P<0.001)and two doses of COVID-19 vaccine(P=0.001)were associated with a shorter time to viral clearance.Multivariable analysis revealed an independent effect of comorbidities(P<0.001)and age(P=0.003).The interaction effect between age and comorbidity showed that the negative association between age and time to virus clearance remained significant only in patients without underlying diseases(P<0.001).Conclusion This study describes the clinical characteristics of children infected with the Omicron variant of SARS-CoV-2 and calls for additional studies to evaluate the effectiveness and safety of vaccination against COVID-19 in children.
基金This work was supported by the Deutsche Forschungsgemeinschaft DFG （SCHW634/32-1） and National Natural Science Foundation of China （grant numbers 31870678）.
文摘Plants emit an overabundance of volatile compounds, which act in their producers either as appreciated attractants to lure beneficial animals or as repellent toxins to deter pests in a species-specific and concentration-dependent manner. Plants have evolved solutions to provide sufficient volatiles without poisoning themselves. Uridine-diphosphate sugar-dependent glycosyltransferases （UGTs） acting on vola-tiles is one important part of this sophisticated system, which balances the levels of bioactive metabolites and prepares them for cellular and long-distance transport and storage but enables the remobilization of disarmed toxins for the benefit of plant protection. This review provides an overview of the research history of glycosidically bound volatiles （GBVs）, a relatively new group of plant secondary metabolites, and discusses the role of UGTs in the production of GBVs for plant protection.
文摘Liver sinusoidal endothelial cells （LSECs） line the liver sinusoids and separate passenger leukocytes in the sinusoidal lumen from hepatocytes. LSECs further act as a platform for adhesion of various liver-resident immune cell populations such as Kupffer cells, innate lymphoid cells or liver dendritic cells. In addition to having an extraordinary scavenger function, LSECs possess potent immune functions, serving as sentinel cells to detect microbial infection through pattern recognition receptor activation and as antigen （cross）-presenting cells. LSECs cross-prime naive CD8 T cells, causing their rapid differentiation into memory T cells that relocate to secondary lymphoid tissues and provide protection when they re-encounter the antigen during microbial infection. Cross-presentation of viral antigens by LSECs derived from infected hepatocytes triggers local activation of effector CD8 T cells and thereby assures hepatic immune surveillance. The immune function of LSECs complements conventional immune-activating mechanisms to accommodate optimal immune surveillance against infectious microorganisms while preserving the integrity of the liver as a metabolic organ.
基金supported financially by the National Key R&D Program of China (No. 2017YFB0703104)the National Natural Science Foundation of China (No. 51401219)
文摘The effects of welding speed on the macroscopic and microscopic residual stresses(RSes) in friction stir welded 17 vol.% SiCp/2009 Al-T4 composite plates were studied via neutron diffraction and an improved decoupled hierarchical multiscale modeling methods. Measurements showed that the macroscopic and total RSes had the largest variations in the longitudinal direction(LD). Increasing the welding speed led to higher values of measured LD macroscopic and total RSes in the matrix. The welding speed also significantly influenced the distributions and magnitudes of the microscopic RSes. The RSes were predicted via an improved hierarchical multiscale model, which includes a constant coefficient of friction based thermal model. The RSes in the composite plates before friction stir welding(FSW) were computed and then set as the initial states of the FSW process during modeling. This improved decoupled multiscale model provided improved predictions of the temperature and RSes compared with our previous model.
基金support from the DFG Leibniz Prize and SFB 1123.
文摘Originally developed for diagnostic ultrasound imaging,piezoelectric transducers are the most widespread technology employed in optoacoustic(photoacoustic)signal detection.However,the detection requirements of optoacoustic sensing and imaging differ from those of conventional ultrasonography and lead to specifications not sufficiently addressed by piezoelectric detectors.Consequently,interest has shifted to utilizing entirely optical methods for measuring optoacoustic waves.All-optical sound detectors yield a higher signal-to-noise ratio per unit area than piezoelectric detectors and feature wide detection bandwidths that may be more appropriate for optoacoustic applications,enabling several biomedical or industrial applications.Additionally,optical sensing of sound is less sensitive to electromagnetic noise,making it appropriate for a greater spectrum of environments.In this review,we categorize different methods of optical ultrasound detection and discuss key technology trends geared towards the development of all-optical optoacoustic systems.We also review application areas that are enabled by all-optical sound detectors,including interventional imaging,non-contact measurements,magnetoacoustics,and nondestructive testing.
