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1.
Proc Natl Acad Sci U S A ; 120(15): e2214558120, 2023 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-37011203

RESUMO

The modern pattern of the Asian monsoon is thought to have formed around the Oligocene/Miocene transition and is generally attributed to Himalaya-Tibetan Plateau (H-TP) uplift. However, the timing of the ancient Asian monsoon over the TP and its response to astronomical forcing and TP uplift remains poorly known because of the paucity of well-dated high-resolution geological records from the TP interior. Here, we present a precession-scale cyclostratigraphic sedimentary section of 27.32 to 23.24 million years ago (Ma) during the late Oligocene epoch from the Nima Basin to show that the South Asian monsoon (SAM) had already advanced to the central TP (32°N) at least by 27.3 Ma, which is indicated by cyclic arid-humid fluctuations based on environmental magnetism proxies. A shift of lithology and astronomically orbital periods and amplified amplitude of proxy measurements as well as a hydroclimate transition around 25.8 Ma suggest that the SAM intensified at ~25.8 Ma and that the TP reached a paleoelevation threshold for enhancing the coupling between the uplifted plateau and the SAM. Orbital short eccentricity-paced precipitation variability is argued to be mainly driven by orbital eccentricity-modulated low-latitude summer insolation rather than glacial-interglacial Antarctic ice sheet fluctuations. The monsoon data from the TP interior provide key evidence to link the greatly enhanced tropical SAM at 25.8 Ma with TP uplift rather than global climate change and suggest that SAM's northward expansion to the boreal subtropics was dominated by a combination of tectonic and astronomical forcing at multiple timescales in the late Oligocene epoch.

2.
Int J Paediatr Dent ; 32(6): 785-792, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35315146

RESUMO

AIM: The purpose of this research was to present an artificial intelligence (AI) model, which can automatically segment and detect ectopic eruption of first permanent molars (EMMs) in early mixed dentition on panoramic radiographs using the no-new-Net (nnU-Net) model. DESIGN: A total of 438 EMMs obtained from 285 panoramic radiographs were included in this study. An AI model based on nnU-Net was trained to segment and detect EMMs. The performance of the model was evaluated by the intersection over union (IoU), precision, F1-score, accuracy and FROC. Furthermore, the detecting performance of nnU-Net was compared with that of three dentists with different years of experience using the McNemar chi-squared test. The reliability of different dentists was evaluated by intraclass correlation coefficients (ICCs). RESULTS: The nnU-Net yielded an IoU of 0.834, a precision of 0.845, an F1-score of 0.902 and an accuracy of 0.990, whereas the dentists yielded a mean IoU of 0.530, a mean precision of 0.539, a mean F1-score of 0.699 and a mean accuracy of 0.811. The ICC of different dentists was 0.776. The statistical analysis of the McNemar chi-squared test showed that the nnU-Net results were statistically significant and superior to those of dentists (p < .05). CONCLUSION: This study validated an AI model based on nnU-Net for automatically segmenting and detecting EMMs more consistently and accurately on panoramic radiography.


Assuntos
Inteligência Artificial , Dente Molar , Dentição Mista , Humanos , Dente Molar/diagnóstico por imagem , Radiografia Panorâmica , Reprodutibilidade dos Testes
3.
Am J Orthod Dentofacial Orthop ; 162(5): e230-e245, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36055884

RESUMO

INTRODUCTION: This study aimed to investigate the midsagittal reference plane (MSP) reliability derived from the 3-dimensional characteristics of patients with or without facial asymmetry in the anterior cranial base (ACB). METHODS: We divided the cone-beam computed tomography (CBCT) images of 60 adult patients into maxillofacial symmetry and asymmetry groups. The ACB models were 3-dimensionally constructed, and then symmetrical characteristics were evaluated with surface asymmetry for each group. The reliability of the MSP derived from the symmetry of the anterior cranial base (MSPACB) was assessed in comparison with the true craniofacial symmetry plane determined using the morphometric method. RESULTS: The ACB was symmetrical, as demonstrated by slight surface asymmetry. The MSPACB was reliable for maxillofacial asymmetrical analysis as the intraobserver and interobserver measurements using the MSPACB were of excellent agreement, and there was no significant difference between MSPACB and morphometric method in asymmetrical measurements in both groups. The MSPACB remained stable (maximum deviation <0.32 mm) when cranial landmark identification errors (1 mm and 4 mm) were simulated. CONCLUSIONS: MSPACB is reliable for patients with or without facial asymmetry in maxillofacial asymmetry analysis, which is beneficial to patients with severe midfacial asymmetry or trauma when conventional landmarks are displaced or disappear. When using MSPACB for patients with cranial malformations or those whose ACBs differ from normal dimensions, caution should be taken.


Assuntos
Pontos de Referência Anatômicos , Assimetria Facial , Adulto , Humanos , Assimetria Facial/diagnóstico por imagem , Reprodutibilidade dos Testes , Cefalometria/métodos , Base do Crânio/diagnóstico por imagem , Tomografia Computadorizada de Feixe Cônico/métodos , Imageamento Tridimensional/métodos
4.
BMC Oral Health ; 22(1): 106, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35365122

RESUMO

BACKGROUND: Radiographic periodontal bone loss is one of the most important basis for periodontitis staging, with problems such as limited accuracy, inconsistency, and low efficiency in imaging diagnosis. Deep learning network may be a solution to improve the accuracy and efficiency of periodontitis imaging staging diagnosis. This study aims to establish a comprehensive and accurate radiological staging model of periodontal alveolar bone loss based on panoramic images. METHODS: A total of 640 panoramic images were included, and 3 experienced periodontal physicians marked the key points needed to calculate the degree of periodontal alveolar bone loss and the specific location and shape of the alveolar bone loss. A two-stage deep learning architecture based on UNet and YOLO-v4 was proposed to localize the tooth and key points, so that the percentage of periodontal alveolar bone loss was accurately calculated and periodontitis was staged. The ability of the model to recognize these features was evaluated and compared with that of general dental practitioners. RESULTS: The overall classification accuracy of the model was 0.77, and the performance of the model varied for different tooth positions and categories; model classification was generally more accurate than that of general practitioners. CONCLUSIONS: It is feasible to establish deep learning model for assessment and staging radiographic periodontal alveolar bone loss using two-stage architecture based on UNet and YOLO-v4.


Assuntos
Perda do Osso Alveolar , Aprendizado Profundo , Periodontite , Perda do Osso Alveolar/diagnóstico por imagem , Odontólogos , Humanos , Periodontite/diagnóstico por imagem , Papel Profissional
5.
BMC Infect Dis ; 20(1): 511, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32669095

RESUMO

BACKGROUND: Salmonella enterica subsp. enterica serovar Typhimurium infections continue to be a significant public health threat worldwide. The aim of this study was to investigate antibiotic resistance among 147 S. Typhimurium isolates collected from patients in Henan, China from 2006 to 2015. METHODS: 147 S. Typhimurium isolates were collected from March 2006 to November 2015 in Henan Province, China. Antimicrobial susceptibility testing was performed, and the resistant genes of ciprofloxacin, cephalosporins (ceftriaxone and cefoxitin) and azithromycin were detected and sequenced. Clonal relationships were assessed by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). RESULTS: Of the 147 isolates, 91.1% were multidrug resistant (MDR), with 4.1% being resistant to all antibiotic classes tested. Of concern, 13 MDR isolates were co-resistant to the first-line treatments cephalosporins and ciprofloxacin, while three were also resistant to azithromycin. Seven PFGE patterns were identified among the 13 isolates. All of the isolates could be assigned to one of four main groups, with a similarity value of 89%. MLST assigned the 147 isolates into five STs, including two dominant STs (ST19 and ST34). Of the 43 ciprofloxacin-resistant isolates, 39 carried double gyrA mutations (Ser83Phe, Asp87Asn/Tyr/Gly) and a single parC (Ser80Arg) mutation, including 1 isolate with four mutations (gyrA: Ser83Phe, Asp87Gly; parC: Ser80Arg; parE: Ser458Pro). In addition, 12 isolates not only carried mutations in gyrA and parC but also had at least one plasmid-mediated quinolone resistance (PMQR) gene. Among the 32 cephalosporin-resistant isolates, the most common extended-spectrum ß-lactamase (ESBL) gene was blaOXA-1, followed by blaCTX-M, blaTEM-1, and blaCMY-2. Moreover, the mphA gene was identified in 5 of the 15 azithromycin-resistant isolates. Four MDR isolates contained ESBL and PMQR genes, and one of them also carried mphA in addition. CONCLUSION: The high level of antibiotic resistance observed in S. Typhimurium poses a great danger to public health, so continuous surveillance of changes in antibiotic resistance is necessary.


Assuntos
Antibacterianos/uso terapêutico , Azitromicina/uso terapêutico , Cefalosporinas/uso terapêutico , Ciprofloxacina/uso terapêutico , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Salmonella/tratamento farmacológico , Infecções por Salmonella/epidemiologia , Salmonella/genética , Sorogrupo , Adolescente , Adulto , Criança , Pré-Escolar , China/epidemiologia , Eletroforese em Gel de Campo Pulsado , Feminino , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Tipagem de Sequências Multilocus , Infecções por Salmonella/microbiologia , Adulto Jovem
6.
Appl Environ Microbiol ; 84(8)2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-29500254

RESUMO

Since the initial discovery of mcr-1 in an Escherichia coli isolate from China, the gene has also been detected in Klebsiella pneumoniae and Salmonella enterica but is rarely reported in other Enterobacteriaceae Here, we report the isolation and identification of a Shigella flexneri strain harboring mcr-1 from stool samples in a pig farm in China from 2009. The MIC of colistin for the isolate is 4 µg/ml. Conjugation assays showed that the donor S. flexneri strain has functional and transferable colistin resistance. Sequencing revealed that mcr-1 was present on a putative composite transposon flanked by inverted repeats of ISApl1IMPORTANCE There are four species of Shigella, and Shigella flexneri is the most frequently isolated species in low- and middle-income countries (LMICs). In this study, we report a functional, transferable, plasmid-mediated mcr-1 gene in S. flexneri We have shown that mcr-1 is located on a novel composite transposon which is flanked by inverted repeats of ISApl1 The host strain is multidrug resistant, and this multidrug resistance is also transferable. The finding of a functional mcr-1 gene in S. flexneri, a human-associated Enterobacteriaceae family member, is a cause for concern as infections due to S. flexneri are the main Shigella infections in most low- and middle-income countries.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Colistina/farmacologia , Farmacorresistência Bacteriana/genética , Shigella flexneri/genética , Sus scrofa/microbiologia , Animais , Proteínas de Bactérias/metabolismo , Fezes/microbiologia , Plasmídeos/genética , Shigella flexneri/efeitos dos fármacos
7.
BMC Infect Dis ; 18(1): 292, 2018 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-29970024

RESUMO

BACKGROUND: Among 2179 Salmonella isolates obtained during national surveillance for salmonellosis in China from 2005 to 2013, we identified 46 non-H2S-producing strains originating from different sources. METHODS: The isolates were characterized in terms of antibiotic resistance and genetic variability by pulsed-field gel electrophoresis and multilocus sequence typing. Mutation in the phs operon, which may account for the non-H2S-producing phenotype of the isolated Salmonella strains, was performed in this study. RESULTS: Among isolated non-H2S-producing Salmonella strains, more than 50% were recovered from diarrhea patients, of which H2S-negative S. Gallinarum, S. Typhimurium, S. Choleraesuis and S. Paratyphi A isolates constituted 76%. H2S-negative isolates exhibited a high rate of resistance to ticarcillin, ampicillin, and tetracycline, and eight of them had the multidrug resistance phenotype. Most H2S-negative Salmonella isolates had similar pulsed-field gel electrophoresis profiles and the same sequence type as H2S-positive strains, indicating a close origin, but carried mutations in the phsA gene, which may account for the non-H2S-producing phenotype. CONCLUSIONS: Our data indicate that multiple H2S-negative strains have emerged and persist in China, emphasizing the necessity to implement efficient surveillance measures for controlling dissemination of these atypical Salmonella strains.


Assuntos
Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos , Sulfeto de Hidrogênio/metabolismo , Infecções por Salmonella/microbiologia , Salmonella/efeitos dos fármacos , Animais , China , Eletroforese em Gel de Campo Pulsado , Humanos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Fenótipo , Salmonella/genética , Salmonella/isolamento & purificação , Salmonella/metabolismo , Salmonella enterica , Sorogrupo
8.
Artigo em Inglês | MEDLINE | ID: mdl-28373192

RESUMO

Here, we report for the first time a waterborne outbreak of Shigella sonnei in China in 2015. Eleven multidrug-resistant (MDR) S. sonnei isolates were recovered, showing high resistance to azithromycin and third-generation cephalosporins in particular, due to an mph(A)- and blaCTX-M-14-harboring IncB/O/K/Z group transmissible plasmid of 104,285 kb in size. Our study highlights the potential prevalence of the MDR outbreak of S. sonnei in China and its further dissemination worldwide with the development of globalization.


Assuntos
Azitromicina/farmacologia , Cefalosporinas/farmacologia , Shigella sonnei/efeitos dos fármacos , Antibacterianos/farmacologia , China , Farmacorresistência Bacteriana Múltipla/genética , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Shigella sonnei/genética
9.
J Theor Biol ; 403: 59-67, 2016 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-27179460

RESUMO

How to select and combine good traits of rice to get high-production individuals is one of the key points in developing crop ideotype cultivation technologies. Existing cultivation methods for producing ideal plants, such as field trials and crop modeling, have some limits. In this paper, we propose a method based on a genetic algorithm (GA) and a functional-structural plant model (FSPM) to optimize plant types of virtual rice by dynamically adjusting phenotypical traits. In this algorithm, phenotypical traits such as leaf angles, plant heights, the maximum number of tiller, and the angle of tiller are considered as input parameters of our virtual rice model. We evaluate the photosynthetic output as a function of these parameters, and optimized them using a GA. This method has been implemented on GroIMP using the modeling language XL (eXtended L-System) and RGG (Relational Growth Grammar). A double haploid population of rice is adopted as test material in a case study. Our experimental results show that our method can not only optimize the parameters of rice plant type and increase the amount of light absorption, but can also significantly increase crop yield.


Assuntos
Algoritmos , Oryza/genética , Característica Quantitativa Herdável , Absorção de Radiação , Simulação por Computador , Aptidão Genética , Luz , Tamanho do Órgão , Oryza/anatomia & histologia , Oryza/efeitos da radiação , Fenótipo , Reprodutibilidade dos Testes
10.
J Theor Biol ; 387: 136-43, 2015 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-26408336

RESUMO

A method to compute the similarity between different plants is proposed, using features of a plant׳s topological structure and peripheral contour, as well as its geometry. The topological structures are described using tree graphs, and their similarity can be calculated based on the edit distance of these graphs. The peripheral contour of a plant is abstracted by its three-dimensional convex hull, which is projected in several directions. The similarity of the different projections is calculated by an algorithm to compute the similarity of two-dimensional shapes. The similarity of the geometrical detail is computed by considering the geometrical properties of different level branches. Finally the overall similarity between different plants is calculated by combining these different similarity measures. The validity of proposed method is evaluated by detailed experiments.


Assuntos
Imageamento Tridimensional/métodos , Plantas/anatomia & histologia , Algoritmos , Simulação por Computador , Especificidade da Espécie , Árvores/anatomia & histologia
11.
J Org Chem ; 80(9): 4760-5, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25825953

RESUMO

The synthesis of ß-alkynyl ketones was achieved in good to excellent yields by an iron-catalyzed domino reaction of N-cyclohexyl propargylamines and 1,3-diketones. A plausible mechanism involving nucleophilic substitution, intramolecular cyclization, and reverse Claisen condensation for this process is proposed.

12.
J Org Chem ; 79(18): 8882-8, 2014 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-25171324

RESUMO

We report an efficient route to pyridine derivatives via an FeCl3-catalyzed four-component nucleophilic addition/intermolecular cyclization. This simple fragment assembly strategy uses mild conditions and affords a broad range of polysubstituted pyridines in moderate to good yield from simple and readily available starting materials. A plausible mechanism for this process is proposed.


Assuntos
Cloretos/química , Compostos Férricos/química , Piridinas/síntese química , Catálise , Ciclização , Estrutura Molecular , Piridinas/química
13.
Heliyon ; 10(10): e31052, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38799758

RESUMO

Objectives: To establish a novel deep learning networks (MSF-MPTnet) based on panoramic radiographs (PRs) for automatic assessment of relationship between maxillary sinus floor (MSF) and maxillary posterior teeth (MPT), and to compare accuracy of MSF-MPTnet, dentists and radiologists identifying contact relationship. Study design: A total of 1035 PRs and 1035 Cone-beam computed tomographys (CBCT)images were collected from January 2018 to April 2022. The relationships were classified into class I and II by CBCT. Class I represents non-contact group, and class II represents contact group. 350 PRs were randomly selected as test dataset and accuracy of MSF-MPTnet, dentists, and radiologists was compared. Results: The intraclass correlation coefficient of dentists was 0.460-0.690 and it was 0.453-0.664 for radiologists. Sensitivity and accuracy of MSF-MPTnet were 0.682-0.852and 0.890-0.951, indicating that the output performance of MSF-MPTnet was reliable. Accuracy of maxillary premolars and molars were 79.7%-90.3 %, 76.2%-89.2 % and 72.9%-88.3 % in MSF-MPTnet model, dentists and radiologists. Accuracy of class I relationship in the MSF-MPTnet model (67.7%-94.6 %) was higher than that of dentists (56.5%-84.6 %) in maxillary first premolars and right second premolar, and accuracy of class I relationship in the MSF-MPTnet model is also higher than radiologists (40.0%-78.1 %) in all teeth positions (p < 0.05). Conclusions: MSF-MPTnet model could increase detecting accuracy of the relationship between MSF and MPT, minimize pseudo contact relationship and reduce frequency of CBCT use.

14.
Front Public Health ; 10: 852410, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35372245

RESUMO

Patients treated in the intensive care unit (ICU) are closely monitored and receive intensive treatment. Such aggressive monitoring and treatment will generate high-granularity data from both electronic healthcare records and nursing charts. These data not only provide infrastructure for daily clinical practice but also can help to inform clinical studies. It is technically challenging to integrate and cleanse medical data from a variety of sources. Although there are several open-access critical care databases from western countries, there is a lack of this kind of database for Chinese adult patients. We established a critical care database involving patients with infection. A large proportion of these patients have sepsis and/or septic shock. High-granularity data comprising laboratory findings, baseline characteristics, medications, international statistical classification of diseases (ICD) code, nursing charts, and follow-up results were integrated to generate a comprehensive database. The database can be utilized for a variety of clinical studies. The dataset is fully accessible at PhysioNet(https://physionet.org/content/icu-infection-zigong-fourth/1.0/).


Assuntos
Cuidados Críticos , Bases de Dados Factuais , Sepse , Adulto , Humanos , Unidades de Terapia Intensiva
15.
Front Genet ; 13: 855355, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35480301

RESUMO

Gastric cancer is a kind of gastrointestinal tumor with high morbidity and mortality. Finding effective methods for early diagnosis and treatment of gastric cancer has important significance and application prospects. MicroRNAs without protein coding potential affect the occurrence and development of gastric cancer. This study aims to explore the biological function and mechanism of microRNA-107 (miR-107) in gastric cancer. The results show that miR-107 is low expressed in gastric cancer, while TRIAP1 is highly expressed; the overexpression of miR-107 can inhibit the progression of gastric cancer in vivo and in vitro, while the overexpression plasmid of TRIAP1 can restore the miR-107 mimic-induced cell proliferation and metastasis inhibition, and the small interfering RNA of TRIAP1 can inhibit the cell proliferation and invasion induced by miR-107 inhibitor. In conclusion, the results of this study show that miR-107 can inhibit the proliferation of gastric cancer in vivo and in vitro by targeting TRIAP1.

16.
Science ; 378(6624): 1074-1079, 2022 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-36480632

RESUMO

The uplift of the Tibet Plateau (TP) during the Miocene is crucial to understanding the evolution of Asian monsoon regimes and alpine biodiversity. However, the northern Tibet Plateau (NTP) remains poorly investigated. We use pollen records of montane conifers (Tsuga, Podocarpus, Abies, and Picea) as a new paleoaltimetry to construct two parallel midrange paleoelevation sequences in the NTP at 1332 ± 189 m and 433 ± 189 m, respectively, during the Middle Miocene [~15 million years ago (Ma)]. Both midranges increased rapidly to 3685 ± 87 m in the Late Miocene (~11 Ma) in the east, and to 3589 ± 62 m at ~7 Ma in the west. Our estimated rises in the east and west parts of the NTP during 15 to 7 Ma, together with data from other TP regions, indicate that during the Late Miocene the entire plateau may have reached a high elevation close to that of today, with consequent impacts on atmospheric precipitation and alpine biodiversity.


Assuntos
Biodiversidade , Evolução Biológica , Fenômenos Geológicos , Traqueófitas , Tibet , Polinização
17.
Diagnostics (Basel) ; 11(9)2021 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-34574005

RESUMO

This study aimed to develop a novel detection model for automatically assessing the real contact relationship between mandibular third molars (MM3s) and the inferior alveolar nerve (IAN) based on panoramic radiographs processed with deep learning networks, minimizing pseudo-contact interference and reducing the frequency of cone beam computed tomography (CBCT) use. A deep-learning network approach based on YOLOv4, named as MM3-IANnet, was applied to oral panoramic radiographs for the first time. The relationship between MM3s and the IAN in CBCT was considered the real contact relationship. Accuracy metrics were calculated to evaluate and compare the performance of the MM3-IANnet, dentists and a cooperative approach with dentists and the MM3-IANnet. Our results showed that in comparison with detection by dentists (AP = 76.45%) or the MM3-IANnet (AP = 83.02%), the cooperative dentist-MM3-IANnet approach yielded the highest average precision (AP = 88.06%). In conclusion, the MM3-IANnet detection model is an encouraging artificial intelligence approach that might assist dentists in detecting the real contact relationship between MM3s and IANs based on panoramic radiographs.

18.
Sci Bull (Beijing) ; 66(22): 2320-2328, 2021 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-36654458

RESUMO

As a crucial part of the Asian monsoon stretching from tropical India to temperate East Asia, the Indian monsoon (IM) contributes predominant precipitation over Asian continent. However, our understanding of IM's onset, development and the underlying driving mechanisms is limited. Increasing evidence indicates that the IM began in the Eocene or even the Paleocene and was unexceptionally linked to the early rise of the Tibetan Plateau (TP). These were challenged by the heterogeneous and diachronous uplift of the TP and all the reported records were confined to tropical zone under tropical monsoon driven by the Intertropical Convergence Zone (ITCZ) that is irrelevant to the TP. Therefore, reliable paleoclimatic records from the extra-tropical IM region is crucial to reveal how the tropical IM expanded to subtropical and temperate zones and what driving factors might be related to it. Here we present robust Eocene paleoenvironmental records from central Yunnan (~26°N) in subtropical East Asia. The multiproxy results of two sites demonstrate a consistent sudden switch from a dry environment in the early Eocene to a seasonally wet one at 41 Ma, suggesting a jump of the tropical IM to the southern subtropical zone at 41 Ma. The full collision of India with Asia, and the resulting changes in paleogeography at 41 Ma (closure of the Neotethys sea, retreat of the Paratethys seas, fast northward movement of the southern margin of the TP and rise of the central TP), aided by synchronous Antarctic cooling, might have worked together to drive the IM enhancement and northward expansion.


Assuntos
Clima Extremo , Regiões Antárticas , Ásia , Ásia Oriental , China , Índia
19.
Comput Methods Programs Biomed ; 184: 105286, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31891901

RESUMO

BACKGROUND AND OBJECTIVE: Myocardial infarction (MI) is a myocardial anoxic incapacitation caused by severe cardiovascular obstruction that can cause irreversible injury or even death. In medical field, the electrocardiogram (ECG) is a common and effective way to diagnose myocardial infarction, which often requires a wealth of medical knowledge. It is necessary to develop an approach that can detect the MI automatically. METHODS: In this paper, we propose a multi-branch fusion framework for automatic MI screening from 12-lead ECG images, which consists of multi-branch network, feature fusion and classification network. First, we use text detection and position alignment to automatically separate twelve leads from ECG images. Then, those 12 leads are input into the multi-branch network constructed by a shallow neural network to get 12 feature maps. After concatenating those feature maps by depth fusion, classification is explored to judge the given ECG is MI or not. RESULTS: Based on extensive experiments on an ECG image dataset, performances of different combinations of structures are analyzed. The proposed network is compared with other networks and also compared with physicians in the practical use. All the experiments verify that the proposed method is effective for MI screening based on ECG images, which achieves accuracy, sensitivity, specificity and F1-score of 94.73%, 96.41%, 95.94% and 93.79% respectively. CONCLUSIONS: Rather than using the typical one-dimensional electrical ECG signal, this paper gives an effective model to screen MI by analyzing 12-lead ECG images. Extracting and analyzing these 12 leads from their corresponding ECG images is a good attempt in the application of MI screening.


Assuntos
Eletrocardiografia/métodos , Infarto do Miocárdio/diagnóstico , Eletrocardiografia/instrumentação , Humanos , Modelos Teóricos , Infarto do Miocárdio/fisiopatologia , Sensibilidade e Especificidade
20.
Int J Antimicrob Agents ; 52(1): 14-21, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29501823

RESUMO

Since the plasmid-mediated polymyxin resistance gene mcr-1 was first reported in Escherichia coli and Klebsiella pneumoniae in China, only one mcr-1-positive isolate of Shigella sonnei, containing inactivated mcr-1, has been reported worldwide. In this study, 1650 historical S. sonnei strains isolated from 2003-2015 in China were screened for the mcr-1 gene. Antimicrobial susceptibilities and resistance genes of mcr-1-positive isolates were determined, and the transferability of polymyxin resistance by plasmid conjugation was investigated. Pulsed-field gel electrophoresis (PFGE), plasmid profiles and Southern blotting were used to analyse genetic relationships and plasmid characteristics, and mcr-1-positive plasmids were sequenced. Six mcr-1-positive S. sonnei isolates from Shanghai (2010-2012) with polymyxin B resistance (MICs 4-8 µg/mL) were identified. Four of these exhibited multidrug resistance, including resistance to azithromycin and third-generation cephalosporins, and co-harboured blaCTX-M-14, mph(A) and blaTEM on different plasmids. mcr-1-positive plasmids shared highly similar IncI2 backbones that resembled reference plasmids, although some differences were observed, including various and abundant insertion sequences/patterns (IS1294, IS1 and ISApl1) and a diverse recombination shufflon region. mcr-1 in S. sonnei may date back to mid-2006. Here we report for the first time the presence of active mcr-1 in multidrug-resistant S. sonnei in China, which has existed since at least 2010. This study highlights the diverse mobile genetic elements on mcr-1-harboring plasmids, potentially resulting in high rates of mcr-1 horizontal transfer among Enterobacteriaceae. These findings emphasise the importance of continuous national and international surveillance of mcr-1-positive Shigella and changes in antibiotic resistance patterns.


Assuntos
Proteínas de Bactérias/genética , Farmacorresistência Bacteriana Múltipla/genética , Shigella sonnei/efeitos dos fármacos , Shigella sonnei/genética , Adulto , Southern Blotting , China , Conjugação Genética , Disenteria Bacilar/microbiologia , Eletroforese em Gel de Campo Pulsado , Humanos , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Polimixina B/farmacologia , Shigella sonnei/isolamento & purificação
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