Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 85
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Nature ; 579(7798): 270-273, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32015507

RESUMO

Since the outbreak of severe acute respiratory syndrome (SARS) 18 years ago, a large number of SARS-related coronaviruses (SARSr-CoVs) have been discovered in their natural reservoir host, bats1-4. Previous studies have shown that some bat SARSr-CoVs have the potential to infect humans5-7. Here we report the identification and characterization of a new coronavirus (2019-nCoV), which caused an epidemic of acute respiratory syndrome in humans in Wuhan, China. The epidemic, which started on 12 December 2019, had caused 2,794 laboratory-confirmed infections including 80 deaths by 26 January 2020. Full-length genome sequences were obtained from five patients at an early stage of the outbreak. The sequences are almost identical and share 79.6% sequence identity to SARS-CoV. Furthermore, we show that 2019-nCoV is 96% identical at the whole-genome level to a bat coronavirus. Pairwise protein sequence analysis of seven conserved non-structural proteins domains show that this virus belongs to the species of SARSr-CoV. In addition, 2019-nCoV virus isolated from the bronchoalveolar lavage fluid of a critically ill patient could be neutralized by sera from several patients. Notably, we confirmed that 2019-nCoV uses the same cell entry receptor-angiotensin converting enzyme II (ACE2)-as SARS-CoV.


Assuntos
Betacoronavirus/classificação , Betacoronavirus/genética , Quirópteros/virologia , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Surtos de Doenças , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , Enzima de Conversão de Angiotensina 2 , Animais , Anticorpos Antivirais/sangue , Betacoronavirus/metabolismo , Betacoronavirus/ultraestrutura , COVID-19 , Linhagem Celular , China/epidemiologia , Chlorocebus aethiops , Feminino , Genoma Viral/genética , Humanos , Masculino , Peptidil Dipeptidase A/metabolismo , Filogenia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/classificação , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genética , SARS-CoV-2 , Homologia de Sequência do Ácido Nucleico , Síndrome Respiratória Aguda Grave , Células Vero
2.
J Environ Manage ; 352: 120057, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38198839

RESUMO

The combination of chlorine-mediated electrochemical advanced oxidation (Cl-EAO) and ultraviolet (UV) radiation (UV-E/Cl) can efficiently remove ammonia from wastewater. However, the synergistic mechanisms between Cl-EAO and UV need to be explored in more detail. Thus, in this study, the ammonia oxidation performance of Cl-EAO and UV-E/Cl systems were compared, while the synergistic mechanisms were identified by the performance of UV/chlorine oxidation (UV-ClO) system and the results of electron paramagnetic resonance (EPR) analysis, free radical inhibition assays, and determination of steady-state concentration of free radicals. It was found that, compared with the Cl-EAO system, UV increased the ammonia removal rate by 42.85% and reduced the active chlorine concentration (56.64%) and nitrate yield (53.61%). In the Cl-EAO, and UV-E/Cl systems, Cl• were detected, and the free radical inhibition assays and determination of steady-state concentration of free radicals suggested that UV increased the concentration of Cl• by 51.47%, resulting in Cl• becoming the major contributor to ammonia oxidation in the UV-E/Cl system. Besides, UV also increase the concentrations of HO• and Cl2•-, which further promoted the organic matter removal in the real domestic wastewater. This study also discussed the ammonia oxidation performance of the UV-E/Cl system in real domestic wastewater, even with the presence of significant levels of organic and inorganic anions in the wastewater, UV increased the ammonia oxidation by 21.95%. The results of this study thus clarify the mechanisms and potential applications of UV-E/Cl technology.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Cloro , Amônia , Águas Residuárias , Raios Ultravioleta , Cloretos , Oxirredução , Radicais Livres , Purificação da Água/métodos
3.
Parasitol Res ; 122(12): 2859-2870, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37801131

RESUMO

Prosthogonimiasis poses a threat to the reproductive system of poultry and wild birds, which are the definitive hosts of the parasite causing this disease. However, the parasite infection of the second intermediate host (dragonfly), the primary vector of this pathogen, is rarely reported. In this study, the prevalence of Prosthogonimus infection in dragonflies was investigated from June 2019 to October 2022 in Heilongjiang Province, northeast China. The species of metacercariae isolated from dragonfly were identified by morphological characteristics, molecular biology techniques, and animal infection experiments. The results showed that 11 species of dragonflies and one damselfly were identified and among six of the dragonflies infected by Prosthogonimus metacercariae, Sympetrum depressiusculum (28.53%) had the highest infection rate among all positive dragonflies, followed by Sympetrum vulgatum (27.86%) and Sympetrum frequens (20.99%), which are preferred hosts, and the total prevalence was 20.39% (2061/10,110) in Heilongjiang Province. Three species of Prosthogoniumus metacercariae were isolated, including Prosthogonimus cuneatus, Prosthogonimus pullucidus, and Prosthogonimus sp., among which P. cuneatus was the dominant species in dragonflies in Heilongjiang Province. This is the first report on the prevalence of Prosthogonimus in dragonflies in China, which provides baseline data for the control of prosthogonimiasis in Heilongjiang Province and a reference for the prevention of prosthogonimiasis in other areas of China.


Assuntos
Odonatos , Trematódeos , Animais , Metacercárias , China/epidemiologia , Prevalência
5.
Environ Res ; 193: 110529, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33278472

RESUMO

A novel La-Mg composite was prepared for the removal of low concentration phosphate and ammonium nitrogen to alleviate the eutrophication problem. The composition and morphology of La-Mg composite was characterized; Its surface was composed of La, Mg, C, and O elements, with a specific surface area of 21.92 m2/g. La-Mg composite presented excellent removal of phosphate (100%) and nitrogen (96.8%), and the adsorption capacity reached 49.72 mg-P/g and 159.30 mg-N/g for separated adsorption. The composite also had a wide pH usability range (3-11 for P and 3-9 for N) and the adsorption process was almost not disturbed by coexisting ions. After adsorption, it could be regenerated by Na2CO3 and reused effectively. For actual water treatment, a very low residual P of 0.01 mg/L and N of 0.05 mg/L were achieved. Furthermore, Mechanism analysis showed that P adsorption involved ligand exchange and electrostatic attraction. The potential mechanisms of N adsorption involved electrostatic attraction and ion exchange. The results showed that the La-Mg composite is a novel and efficient adsorbent for actual water treatment to achieve ultra-low nutrients concentration.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Desnitrificação , Concentração de Íons de Hidrogênio , Cinética , Lantânio , Nitrogênio , Fosfatos , Água
6.
Biochem Biophys Res Commun ; 529(2): 148-155, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32703403

RESUMO

Long noncoding RNAs (lncRNAs) have undergone a comprehensive study for their involvements in tumor treatments. The purpose of our study was to explore the biological effects and regulatory mechanisms of lncRNA LINC01194 (LINC01194) in laryngeal squamous cell carcinoma (LSCC). The levels of LINC01194 in 105 LSCC patients were detected by RT-qPCR. The diagnostic and prognostic value of LINC01194 in LSCC patients were statistically analyzed. The potential functions of LINC01194 in proliferation, apoptosis, and metastasis of LSCC cells were evaluated. The interaction among LINC01194, miR-655 and SOX18 was explored by bioinformatics analysis, luciferase reporter assays and biotinylated RNA pull-down. We found that the expression levels of LINC01194 were highly expressed in LSCC, which was negatively correlated with the clinical outcome of LSCC patients. The area under the ROC curve for LINC01194 was up to 0.8388. Functional assays indicated that LINC01194 knockdown distinctly inhibited LSCC cells proliferation, induced apoptosis, and also attenuated LSCC cells migration and invasion in vitro. Furthermore, we elucidated that LINC01194 promoted SOX18 expression in LSCC cells via functioning as a molecular sponge for miR-655. Overall, based on our findings, LINC01194 served as a tumor promoter and potentially represents a novel prognostic indicator and therapeutic target in LSCC.


Assuntos
Neoplasias Laríngeas/genética , MicroRNAs/genética , RNA Longo não Codificante/genética , Fatores de Transcrição SOXF/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Laríngeas/diagnóstico , Neoplasias Laríngeas/patologia , Prognóstico , Carcinoma de Células Escamosas de Cabeça e Pescoço/diagnóstico , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia
7.
Ecotoxicol Environ Saf ; 191: 110228, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31982684

RESUMO

An efficient MnCeOx composite was successfully synthesized for activation of persulfate to degrade acid orange 7 (AO7) and ofloxacin. Pollutants degradation efficiencies with different catalytic systems were investigated. Results showed the performance of MnCeOx was better than MnOx, CeO2 and MnOx + CeO2. Thus, there was a clear synergistic effect (Se) between Mn and Ce in the composite, and the Se was 73.8% for AO7 and 39.6% for ofloxacin. In addition, AO7 removal fitted 1st order reaction while ofloxacin removal fitted 2nd order reaction in MnCeOx/persulfate system. Moreover, MnCeOx/persulfate system showed high efficiency in pH range of 5-9. Mechanism analysis showed that SO4- and OH on the surface of the catalyst were the main active species, and O2- also played an important role in pollutants degradation. Furthermore, MnCeOx showed high activity in actual water. Finally, the possible degradation pathway of ofloxacin was proposed according to the high performance liquid chromatography-mass spectrometry result. Overall, this study provides an efficient and stable catalyst to activate persulfate to degrade refractory pollutants.


Assuntos
Compostos Azo/metabolismo , Benzenossulfonatos/metabolismo , Cério/química , Compostos de Manganês/química , Ofloxacino/metabolismo , Óxidos/química , Sulfatos/química , Poluentes Químicos da Água/metabolismo , Catálise , Oxirredução
8.
Int Ophthalmol ; 40(4): 975-984, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31925656

RESUMO

BACKGROUND: Nerve growth factor (NGF) and ciliary neurotrophic factor (CNTF) are well-known neurotrophic factors and widely used in the clinical treatment for its promotion effect on peripheral nerve regeneration. And they were also recommended for the acute paralytic strabismus treatment. However, whether the NGF and CNTF have protective effect for the extraocular muscles of acute paralytic strabismus patients is still poorly understood. PURPOSE: In this study, we want to evaluate the biological function of NGF and CNTF on the extraocular muscle cells and reveale the regulation mechanism behind it. METHODS: Firstly, the relative expression of ngf and cntf was assessed by quantitative real-time RT-PCR. Then, the influence of NGF and CNTF on the extraocular muscle cell proliferation was determined by CCK-8. The inflammatory response in muscle cells after NGF and CNTF treatment was evaluated by ELISA and ROS detection. In addition to this, the up-stream regulation of the ngf and cntf expression was also studied. The TargetScan was used for the predication of potential miRNAs targeting with ngf and cntf 30-UTR, which is soon confirmed by luciferase activity assay. RESULTS: all the results in this research indicated that NGF and CNTF could promote the muscle cell proliferation and inhibit the inflammatory levels, then exert protective effect on the muscle cell function. RESULTS: All the results in this research indicated that NGF and CNTF could promote the muscle cell proliferation and inhibit the inflammatory levels, then exert protective effect on the muscle cell function. CONCLUSION: It was conceivable that let 7-5p was the up-stream regulator of ngf and cntf, and let 7-5p might serve as a potential molecular target for acute paralytic strabismus treatment.


Assuntos
Fator Neurotrófico Ciliar/genética , MicroRNAs/genética , Fator de Crescimento Neural/genética , Estrabismo/genética , Doença Aguda , Western Blotting , Células Cultivadas , Fator Neurotrófico Ciliar/biossíntese , Regulação da Expressão Gênica , Humanos , MicroRNAs/metabolismo , Fator de Crescimento Neural/biossíntese , Procedimentos Cirúrgicos Oftalmológicos/métodos , Estudos Retrospectivos , Estrabismo/metabolismo , Estrabismo/cirurgia
9.
J Environ Sci (China) ; 89: 206-217, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31892392

RESUMO

Persulfate (PS)-based oxidation technologies are attracting increasing attentions in water treatment due to their high efficiency and stability. In this study, a novel diatomite supported MnCeOx composite (MnCeOx/diatomite) was prepared and characterized for activation of PS to degrade organic pollutants. Results indicated that diatomite not only dispersed MnCeOx and increased the specific surface area of catalyst, but also improved the low-valence metal site (Mn2+ and Ce3+) and reactive oxygen species site (-OH) of MnCeOx, thus enhancing the activities of MnCeOx. MnCeOx/diatomite/PS showed high efficiency for multiple dyes and pharmaceutical pollutants. Constant rate (k) of MnCeOx/diatomite (kMnCeOx/diatomite) was three times higher than the sum of constant rate of MnCeOx (kMnCeOx) and constant rate of diatomite (kdiatomite). In addition, MnCeOx/diatomite showed wide pH application (5-9). Cl- and NO32- had no effect while SO42- and humid acid had slightly negative effects on MnCeOx/diatomite/PS system. Moreover, MnCeOx/diatomite showed good reusability and stability. Mechanism analyses indicated that electron transfer of Mn and Ce attributed to the activation of PS and oxygen to produce free radicals. SO4-, OH and O2- on the surface of catalyst were the main active free radicals to attack pollutants.


Assuntos
Terra de Diatomáceas/química , Poluentes Ambientais , Compostos Orgânicos/química , Modelos Químicos , Oxirredução , Sulfatos , Poluentes Químicos da Água
10.
J Environ Sci (China) ; 96: 109-116, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32819685

RESUMO

Refractory organic pollutants in water threaten human health and environmental safety, and advanced oxidation processes (AOPs) are effective for the degradation of these pollutants. Catalysts play vital role in AOPs, and Ce-based catalysts have exhibited excellent performance. Recently, the development and application of Ce-based catalysts in various AOPs have been reported. Our study conducts the first review in this rapid growing field. This paper clarifies the variety and properties of Ce-based catalysts. Their applications in different AOP systems (catalytic ozonation, photodegradation, Fenton-like reactions, sulfate radical-based AOPs, and catalytic sonochemistry) are discussed. Different Ce-based catalysts suit different reaction systems and produce different active radicals. Finally, future research directions of Ce-based catalysts in AOP systems are suggested.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Catálise , Humanos , Oxirredução , Águas Residuárias
11.
BMC Vet Res ; 15(1): 446, 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31818287

RESUMO

BACKGROUND: Leishmaniosis, a disease caused by pathogenic Leishmania parasites, remains an unresolved health problem in the New World and the Old World. It is well known that lizards can be infected by a subgenus of Leishmania parasites, i.e. Sauroleishmania, which is non-pathogenic to humans. However, evidence suggests that lizards may also harbor pathogenic Leishmania species including the undetermined Leishmania sp., discovered in our previous work. Leishmania DNA in lizard blood can be detected by using molecular methods, such as the polymerase chain reaction (PCR). RESULTS: Three hundred and sixteen lizards, representing 13 species of four genera, were captured for blood samples collection in Northwest China. Two reliable molecular markers (cytochrome b and heat shock protein 70 genes) were used for detection in the lizard blood samples, to confirm a widespread presence of pathogenic Leishmania parasites and the distribution pattern of Leishmania spp. in lizards from Northwest China. The PCR data indicated positive detection rate for Leishmania in all the tested lizards with an overall prevalence of 57.91% (183/316). Apart from lizard parasites like Leishmania tarentolae and Leishmania sp., several pathogenic Leishmania including L. turanica, L. tropica and L. donovani complex were identified by using phylogenetic analysis. Co-existence of different haplotypes was observed in most Leishmania DNA-positive lizards with an overall rate of 77.6% (142/183). Even mixed infections with different Leishmania species appeared to occur in the lizards with an overall rate of 37.7% (69/183). CONCLUSIONS: Lizards can harbor pathogenic Leishmania spp. Co-existence of different haplotypes or even species of Leishmania indicates mixed infections in natural lizard host. Lizards may contribute to the spread of Leishmania parasites. The pathogenic Leishmania species detected in lizards from Northwest China may be of great eco-epidemiological importance.


Assuntos
Leishmania/classificação , Leishmaniose/epidemiologia , Lagartos/parasitologia , Animais , China/epidemiologia , DNA de Protozoário/sangue , Haplótipos , Leishmania/genética , Lagartos/sangue , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
12.
Proc Natl Acad Sci U S A ; 113(20): 5542-6, 2016 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-27140601

RESUMO

A three-dimensionally preserved 2-mm-long larva of the arthropod Leanchoilia illecebrosa from the 520-million-year-old early Cambrian Chengjiang biota of China represents the first evidence, to our knowledge, of such an early developmental stage in a short-great-appendage (SGA) arthropod. The larva possesses a pair of three-fingered great appendages, a hypostome, and four pairs of well-developed biramous appendages. More posteriorly, a series of rudimentary limb Anlagen revealed by X-ray microcomputed tomography shows a gradient of decreasing differentiation toward the rear. This, and postembryonic segment addition at the putative growth zone, are features of late-stage metanauplii of eucrustaceans. L. illecebrosa and other SGA arthropods, however, are considered representative of early chelicerates or part of the stem lineage of all euarthropods. The larva of an early Cambrian SGA arthropod with a small number of anterior segments and their respective appendages suggests that posthatching segment addition occurred in the ancestor of Euarthropoda.


Assuntos
Artrópodes/anatomia & histologia , Biota , Larva/anatomia & histologia , Animais , Artrópodes/ultraestrutura , China , Larva/ultraestrutura , Tomografia Computadorizada por Raios X
13.
J Environ Manage ; 234: 265-272, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30634119

RESUMO

A series of Co3O4-CeO2 mixed metal oxides were synthesized by co-precipitation method and successfully used to activate persulfate for diclofenac removal. The effects of Co:Ce mole ratio, calcination temperature and calcination time on the catalytic activities were investigated. Results showed that the activity of Co3O4-CeO2 catalysts increased with Co:Ce mole ratio from 1:9 to 7:3, and decreased with the calcination temperature from 300 to 800 °C. 90% diclofenac was removed with Co7Ce3-300-1 catalyst (Co:Ce = 7:3, calcinated at 300 °C for 1 h) after 15 min. Moreover, short calcination time and low temperature resulted in smaller crystallite size, more structural defects, more active crystal surfaces and larger surface area of the catalyst, which led to higher removal efficiency of diclofenac. The high ratios of Co2+/Co3+, Ce3+/Ce4+ and Oads/Olatt were very important to enhance the catalytic activity. Finally, a potential reaction mechanism was proposed based on characterization of the fresh and spent catalysts.


Assuntos
Diclofenaco , Óxidos , Catálise , Temperatura
14.
Water Sci Technol ; 79(9): 1675-1684, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31241473

RESUMO

FeNiCeOx was firstly prepared by ultrasonic impregnation method and used to remove diclofenac in a Fenton-like system. The catalytic activity was improved successfully by doping Ni into FeCeOx. The diclofenac removal efficiency reached 97.9% after 30 min reaction. The surface morphology and properties of FeNiCeOx were characterized by Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), Raman and X-ray photoelectron spectroscopy (XPS) analyses. FeNiCeOx in this paper had larger specific surface area than those prepared by other methods, which was attributed to the cavitation effect and hot-spot effect during the ultrasonic synthesis process. Low crystallinity of Fe2O3 and NiO showed by characterization could lead to high interaction of Fe and Ni ions with support of CeO2. They substituted Ce in CeO2, caused lattice contraction and formed more oxygen vacancies, which favoured the catalytic reaction. Meanwhile, Fe and Ce ions both had redox cycles of Fe3+/Fe2+ and Ce4+/Ce3+, which facilitated the electron transfer in the reaction. The synergistic effect among Fe, Ni and Ce might lead to better catalytic performance of FeNiCeOx than any binary metal oxides constituted from the above three elements. Finally, the potential mechanism of diclofenac removal in FeNiCeOx-H2O2 system is proposed.


Assuntos
Diclofenaco/química , Poluentes da Água/química , Catálise , Peróxido de Hidrogênio , Ferro , Ultrassom
15.
Zhonghua Nan Ke Xue ; 25(6): 489-495, 2019 Jun.
Artigo em Zh | MEDLINE | ID: mdl-32223081

RESUMO

OBJECTIVE: To investigate the correlation between the behavioral performance and the expressions of substance P (SP) and neurokinin-1 receptor (NK-1R) in the posterior horn of the L5-S2 spinal cord in rats with chronic prostatitis (CP). METHODS: A CP model was made in 30 adult male SD rats by intraperitoneal injection of 0.5 ml dyphtheria pertussis tetanus (DPT) vaccine and mixed solution of 1 ml prostatein extract and complete adjuvant in a 1∶1 ratio, and another 10 rats were injected with the same volume of normal saline as controls. At 45 (n = 10), 60 (n = 10) and 90 days (n = 10) after modeling, the behavioral changes of the rats were observed by open-field and sucrose consumption tests, the prostatic indexes and levels of serum TNF-α, IL-1ß, IL-2 and IL-10 were obtained, and the expressions of SP and NK1-R in the L5-S2 spinal cord were determined by immunohistochemistry. RESULTS: Compared with the controls, the CP model rats showed obviously decreased horizontal and vertical movement scores and sucrose consumption, particularly in the 90 d group (P < 0.05), significantly reduced prostatic indexes in the 45 d, 60 d and 90 d groups (all P < 0.05), even lower in the 90 d than in the 45 d and 60 d groups (P < 0.05). Edema and lymphocytes were increased in the prostatic tissue with the prolonged time of modeling. The levels of serum TNF-α, IL-1ß, IL-2 and IL-10 were markedly elevated in all the CP rats as compared with those in the controls (P < 0.05), and so were the expressions of SP and NK-1R in the L5-S2 spinal cord (P < 0.05), even more significantly in the 90 d than in the 45 d and 60 d groups (P < 0.05). CONCLUSIONS: Rats with chronic prostatitis are characterized by behavioral manifestation of depression, increased levels of serum TNF-α, IL-1ß, IL-2 and IL-10, and a time-dependent upregulation of the expressions of SP and NK-1R in the posterior horn of the L5-S2 spinal cord, which suggests a correlation between the behavioral performance and the expressions of SP and NK-1R in the L5-S2 spinal cord of the rats.


Assuntos
Comportamento Animal , Prostatite/patologia , Receptores da Neurocinina-1/metabolismo , Medula Espinal/metabolismo , Substância P/metabolismo , Animais , Depressão , Interleucina-10/sangue , Interleucina-1beta/sangue , Interleucina-2/sangue , Masculino , Ratos , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa/sangue
16.
Proc Biol Sci ; 285(1881)2018 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-29925613

RESUMO

Chancelloriids are an extinct group of spiny Cambrian animals of uncertain phylogenetic position. Despite their sponge-like body plan, their spines are unlike modern sponge spicules, but share several features with the sclerites of certain Cambrian bilaterians, notably halkieriids. However, a proposed homology of these 'coelosclerites' implies complex transitions in body plan evolution. A new species of chancelloriid, Allonnia nuda, from the lower Cambrian (Stage 3) Chengjiang Lagerstätte is distinguished by its large size and sparse spination, with modified apical sclerites surrounding an opening into the body cavity. The sclerite arrangement in A. nuda and certain other chancelloriids indicates that growth involved sclerite addition in a subapical region, thus maintaining distinct zones of body sclerites and apical sclerites. This pattern is not seen in halkieriids, but occurs in some modern calcarean sponges. With scleritome assembly consistent with a sponge affinity, and in the absence of cnidarian- or bilaterian-grade features, it is possible to interpret chancelloriids as sponges with an unusually robust outer epithelium, strict developmental control of body axis formation, distinctive spicule-like structures and, by implication, minute ostia too small to be resolved in fossils. In this light, chancelloriids may contribute to the emerging picture of high disparity among early sponges.


Assuntos
Evolução Biológica , Fósseis , Poríferos/crescimento & desenvolvimento , Animais , China , Fósseis/anatomia & histologia , Poríferos/anatomia & histologia
17.
Zhonghua Nan Ke Xue ; 22(7): 602-607, 2016 Jul.
Artigo em Zh | MEDLINE | ID: mdl-28965376

RESUMO

OBJECTIVE: To investigate the expressions of substance P (SP) and neurokinin-1 receptor (NK-1R) in the posterior horn of the L5-S2 spinal cord in the rat model of chronic nonbacterial prostatitis (CNP) at different time points of modeling. METHODS: Forty adult male SD rats were randomly divided into four groups of equal number, control, 45 d model, 60 d model, and 90 d model, and proteins were obtained from the prostatic tissue of another 30 rats. The CNP model was made by intraperitoneal injection of 0.5 ml DPT vaccineand intradermal injection of mixed solution of 1 ml prostatein extract and complete adjuvant at a 1∶1 ratio, while the control rats were injected with the same volume of normal saline. At 45, 60, and 90 days after modeling, we measured the paw withdrawal threshold (PWT) of the rats, determined the levels of TNF-α, IL-1ß, IL-2, and IL-10 in the prostate tissue by ELISA, observed the histomorphological changes in the prostate by transmission electron and light microscopy, and detected the expressions of SP and NK1-R in the L5-S2 spinal cord by immunohistochemistry. RESULTS: The model rats showed significantly increased sensitivity to pain, with remarkably lowered PWT at 45, 60, and 90 days after modeling. The levels of TNF-α, IL-1ß, IL-2, and IL-10 in the prostate tissue were markedly elevated in the CNP models as compared with those in the controls (all P<0.05), most significantly at 90 days (all P<0.05). Immunohistochemistry showed that the expressions of SP and NK-1R were remarkably higher in the CNP model groups than in the control (all P<0.05), the highest at 90 days. Light microscopy revealed no inflammatory cell infiltration in the prostate tissue of the control rats, and obvious edema and increased lymphocytes were observed with the prolonged time of modeling.Transmission electron microscopy showed inflammatory changes in the prostate tissue of the model rats and that peritubular interstitial edema was most obvious at 90 days, with widened intervals between peritubular cells and the epithelial base and increased numbers of fibroblasts and collagen fibrils. CONCLUSIONS: The synthesis of SP and the level of NK-1R were increased in the posterior horn of the L5-S2 spinal cord in the rat model of CNP.


Assuntos
Prostatite/metabolismo , Receptores da Neurocinina-1/metabolismo , Medula Espinal/metabolismo , Substância P/metabolismo , Animais , Interleucina-10/metabolismo , Interleucina-1beta/metabolismo , Interleucina-2/metabolismo , Masculino , Dor , Prostatite/fisiopatologia , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa/metabolismo
18.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(3): 724-8, 2016 Mar.
Artigo em Zh | MEDLINE | ID: mdl-27400514

RESUMO

As one of the necessary steps for data processing of Raman spectroscopy, baseline correction is commonly used to eliminate the interference of fluorescence spectra. The traditional baseline correction algorithm based on polynomial fitting is simple and easy to implement, but its flexibility is poor due to the uncertain fitting order. In this paper, instead of using polynomial fitting, non-uniform B-spline is proposed to overcome the shortcomings of the traditional method. Based on the advantages of the traditional algorithm, the node vector of non-uniform B-spline is fixed adaptively using the peak position of the original Raman spectrum, and then the baseline is fitted with the fixed order. In order to verify this algorithm, the Raman spectra of parathion-methyl and colza oil are detected and their baselines are corrected using this algorithm, the result is made comparison with two other baseline correction algorithms. The experimental results show that the effect of baseline correction is improved by using this algorithm with a fixed fitting order and less parameters, and there is no over or under fitting phenomenon. Therefore, non-uniform B-spline is proved to be an effective baseline correction algorithm of Raman spectroscopy.

19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(8): 2487-91, 2016 Aug.
Artigo em Zh | MEDLINE | ID: mdl-30074351

RESUMO

Based on Plasmon-enhanced Raman Spectroscopy (PERS) technology, the detection system for rapid field determination of synthetic edible pigments in food,such as beverage,meat productsand preserves,is presented. The hardware framework of this detection system is mainly composed of double central control chips (ARM and FPGA), a sample pretreatment module (containing a nanoparticle giving device), a laser diode source, and a spectral data acquisitioning module; Besides, the software can run the sample pretreatment module automatically while receiving the Raman spectrogram. To verify its performance in edible synthetic pigments, the rapid detection system was applied to determine carmine, citrine, allure red in three actual samples (i.e. preserves, sodas, sausage). The relative standard deviations of the sample detection were in the range of ±5%, which indicated that the system developed in this paper have the advantage of favorable sensitivity, excellent repeatability and short testing time. Thus, it meets the requirements for rapid field determination of synthetic pigments in food.

20.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(12): 4082-7, 2016 Dec.
Artigo em Zh | MEDLINE | ID: mdl-30256578

RESUMO

To improve time resolution of the Raman measurement system, we need to adopt short scanning time. In this case, the weak Raman signal with vibrational spectrum of the molecular structure is easily to be buried by the high background noise, which influences the further analysis seriously. So it is necessary to de-noise the raw Raman signals. Conventional methods manage to de-noise signal by means of smoothing or averaging based on the difference between signal and noise in frequency characteristic or statistical features. They are commonly applied in the situation where the background noise is not so strong, and cannot give satisfactory results to the Raman signals with low signal-to-noise ratio. In this paper, the algorithm proposed detects peak positions and get peak half-width based on wavelet transform, and then reconstructs the Raman signals by least square fitting algorithm with characteristic parameters obtained, which extracts the useful signal from high background noise efficiently. In the simulation, the Raman curve fitted by the proposed algorithm was smooth, and the peak positions obtained were accurate, so the signal-to-noise ratio improved significantly. In the experiment, we adopted this algorithm to de-noise the tested Raman signal of Cefuroxime Axetil Tablets and Roxithromycin, respectively. The peak positions, peak half-width and amplitude were obtained and proved to be accurate. Therefore, the useful pure Raman signal could be recovered from the high background noise efficiently by the proposed algorithm, which improved the time resolution of Raman system. Both the simulation and the experiment showed that the proposed method could be easily performed with only a few parameters. Comparing with conventional methods, it could achieve satisfactory results under high background noise and provide accurate and reliable information for further analysis.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA