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1.
J Hazard Mater ; 476: 135080, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38996676

RESUMO

The current carbon dioxide (CO2) evolution-based standard method for determining biodegradable microplastics (MPs) degradation neglects its priming effect on soil organic matter decomposition, which misestimates their biodegradability. Here, a 13C natural abundance method was used to estimate the mineralization of poly(lactic acid) (PLA) MP in various agricultural soils, and to trace its utilization in different microbial groups. In alkaline soils, the PLA-derived CO2 emissions increased with increasing soil carbon/nitrogen (C/N) ratios, and the mineralization of PLA MP concentrations ranged from 3-33 %, whereas the CO2 evolution method probably over- or under-estimated the mineralization of PLA in alkaline soils with different soil C/N ratios. Low PLA mineralization (1-5 %) were found in the acidic soil, and the standard method largely overestimated the mineralization of PLA MP by 1.3- to 3.3-fold. Moreover, the hydrolysate of PLA MP was preferentially assimilated by Gram-negative bacteria, but Gram-positive bacterial decomposition mainly contributed to the release of PLA-derived CO2 at low MP concentrations (≤ 1 %). Overall, the 13C natural abundance method appears to be suitable for tracking the mineralization and microbial utilization of biodegradable PLA in soils, and the PLA-derived C is mainly assimilated and decomposed by bacterial groups.

2.
Exp Dermatol ; 33(7): e15142, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39032085

RESUMO

Frequent itching and incessant scratching are commonly observed in various chronic inflammatory skin conditions, including atopic dermatitis and psoriasis. The persistent and prolonged nature of pruritus can worsen one's quality of life. Keratinocytes (KCs), the predominant cells of the epidermis, have been confirmed to interact with sensory neurons and immune cells and be involved in chronic skin inflammatory diseases associated with pruritus. Initially, KCs and sensory neurons form a unique synapse-like connection within the epidermis, serving as the structural foundation for their interaction. Additionally, several receptors, including toll-like receptors and protease-activated receptor 2, expressed on KCs, become activated in an inflammatory milieu. On the one hand, activated KCs are sources of pro-inflammatory cytokines and neurotrophic factors, such as adenosine triphosphate, thymic stromal lymphopoietin, and nerve growth factor, which directly or indirectly participate in stimulating sensory neurons, thereby contributing to the itch sensations. On the other hand, KCs also function as primary transducers alongside intraepidermal nerve endings, directly initiating pruritic responses. This review summarizes the current literature and highlights the critical role of KCs in the development and persistence of chronic itch in inflammatory skin disorders.


Assuntos
Queratinócitos , Prurido , Humanos , Prurido/etiologia , Prurido/fisiopatologia , Queratinócitos/metabolismo , Doença Crônica , Células Receptoras Sensoriais/metabolismo , Células Receptoras Sensoriais/fisiologia , Dermatite Atópica/complicações , Animais , Citocinas/metabolismo , Psoríase/complicações
3.
Microorganisms ; 12(5)2024 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-38792855

RESUMO

A healthy animal intestine hosts a diverse population of bacteria in a symbiotic relationship. These bacteria utilize nutrients in the host's intestinal environment for growth and reproduction. In return, they assist the host in digesting and metabolizing nutrients, fortifying the intestinal barrier, defending against potential pathogens, and maintaining gut health. Bacterial colonization is a crucial aspect of this interaction between bacteria and the intestine and involves the attachment of bacteria to intestinal mucus or epithelial cells through nonspecific or specific interactions. This process primarily relies on adhesins. The binding of bacterial adhesins to host receptors is a prerequisite for the long-term colonization of bacteria and serves as the foundation for the pathogenicity of pathogenic bacteria. Intervening in the adhesion and colonization of bacteria in animal intestines may offer an effective approach to treating gastrointestinal diseases and preventing pathogenic infections. Therefore, this paper reviews the situation and mechanisms of bacterial colonization, the colonization characteristics of various bacteria, and the factors influencing bacterial colonization. The aim of this study was to serve as a reference for further research on bacteria-gut interactions and improving animal gut health.

4.
Sci Rep ; 14(1): 6102, 2024 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-38480729

RESUMO

The mechanisms underlying the organization and evolution of the telencephalic pallium are not yet clear.. To address this issue, we first performed comparative analysis of genes critical for the development of the pallium (Emx1/2 and Pax6) and subpallium (Dlx2 and Nkx1/2) among 500 vertebrate species. We found that these genes have no obvious variations in chromosomal duplication/loss, gene locus synteny or Darwinian selection. However, there is an additional fragment of approximately 20 amino acids in mammalian Emx1 and a poly-(Ala)6-7 in Emx2. Lentiviruses expressing mouse or chick Emx2 (m-Emx2 or c-Emx2 Lv) were injected into the ventricle of the chick telencephalon at embryonic Day 3 (E3), and the embryos were allowed to develop to E12-14 or to posthatchling. After transfection with m-Emx2 Lv, the cells expressing Reelin, Vimentin or GABA increased, and neurogenesis of calbindin cells changed towards the mammalian inside-out pattern in the dorsal pallium and mesopallium. In addition, a behavior test for posthatched chicks indicated that the passive avoidance ratio increased significantly. The study suggests that the acquisition of an additional fragment in mammalian Emx2 is associated with the organization and evolution of the mammalian pallium.


Assuntos
Córtex Cerebral , Telencéfalo , Camundongos , Animais , Telencéfalo/metabolismo , Córtex Cerebral/metabolismo , Encéfalo/metabolismo , Mamíferos/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Regulação da Expressão Gênica no Desenvolvimento
5.
Artigo em Inglês | MEDLINE | ID: mdl-38270847

RESUMO

Atherosclerosis commonly remains undiagnosed until disease manifestations occur. The disease is associated with dysregulated micro(mi)RNAs, but how this is linked to atherosclerosis-related immune reactions is largely unknown. A mouse model of carotid atherosclerosis, human APOB100-transgenic Ldlr-/- (HuBL), was used to study the spatiotemporal dysregulation of a set of miRNAs. Middle-aged HuBL mice with established atherosclerosis had decreased levels of miR-143-3p in their carotid arteries. In young HuBL mice, early atherosclerosis was observed in the carotid bifurcation, which had lower levels of miR-15a-5p, miR-143-3p, and miR-199a-3p, and higher levels of miR-155-5p. The dysregulation of these miRNAs was reflected by specific immune responses during atheroprogression. Finally, levels of miR-143-3p were 70.6% lower in extracellular vesicles isolated from the plasma of patients with carotid stenosis compared to healthy controls. Since miR-143-3p levels progressively decrease when transitioning between early and late experimental carotid atherosclerosis, we propose it as a biomarker for atherosclerosis.

6.
J Anim Sci ; 1012023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-37899715

RESUMO

New feed additives as antibiotics substitutes are in urgent need in poultry production. Nano-composite of copper and carbon (NCCC), a novel copper donor with stronger antibacterial properties, is expected to promote broiler growth and diminish the negative effects of excess copper (Cu). Hence, the purpose of this study is to investigate the effects of NCCC on growth performance, immunity, and antioxidant ability of yellow-feathered broilers. A total of 240 1-d-old male yellow-feathered broilers were selected and randomly divided into four groups, with five replications per group and 12 birds per replication. The CON group was fed corn-soybean basal diets, while the N50, N100, and N200 groups were supplemented with 50, 100, and 200 mg/kg of NCCC in basal diets, respectively. The trial lasted for 63 d. The results demonstrated that only 200 mg/kg NCCC addition significantly increased the Cu content in serum and feces, and liver Cu content linearly increased with NCCC dosage increment (P < 0.05). Meanwhile, NCCC supplementation did not alter the growth performance, slaughter performance, immune organ indexes, and liver antioxidant ability of broilers (P > 0.05), but optimized the serum cytokine pattern by elevating the level of serum IL-10 (P < 0.05), and there were linear and quadratic increases in serum IL-4 with NCCC dosage increment (P < 0.05). On the whole, in spite of no impact on growth performance, 50 mg/kg NCCC was optimal to supplement in chicken diets due to the rise of serum IL-10 level and no extra environmental pollution and tissue residues.


Livestock and poultry industries require eco-friendly antibacterial agents and growth promoters due to the ban on antibiotics in the European Union and China. High-dose copper is considered a bactericide and has the advantage of growth promotion in animals, but it also disturbs the absorption of other metal elements and causes heavy metal residues. In this experiment, a nano-composite of copper and carbon (NCCC) was chosen as an alternative copper donor, hoping to not only inherit the growth-promoting merit but also diminish the disadvantage of excess copper. Hence, the effects of NCCC on growth performance, immune function, and antioxidant capacity of yellow-feathered broilers were explored, and we discovered that there were no copper residues in liver, serum, and feces after 50 or 100 mg/kg NCCC treatment. Meanwhile, obvious increases in levels of serum IL-10 and IL-4 were observed with NCCC dosage increment, despite no notable changes in the growth performance, slaughter performance, and liver antioxidant ability of chickens. As a result, NCCC has been found to optimize serum cytokine pattern but not promote the growth of broilers.


Assuntos
Antioxidantes , Cobre , Animais , Masculino , Cobre/farmacologia , Galinhas , Interleucina-10 , Suplementos Nutricionais , Dieta/veterinária , Ração Animal/análise
7.
iScience ; 26(9): 107485, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37636055

RESUMO

Smart wearable sensors are electronic devices worn on the body that collect, process, and transmit various physiological data. Compared to traditional devices, their advantages in terms of portability and comfort have made them increasingly important in the medical field. This review takes a unique clinical physician's standpoint, diverging from conventional sensor-type-based classifications, and provides a comprehensive overview of the diverse clinical applications of wearable sensors in recent years. In this review, we categorize these applications according to different diseases, encompassing skin diseases and injuries, cardiovascular diseases, abnormal human motion, as well as endocrine and metabolic disorders. Additionally, we discuss the challenges and perspectives hindering the development of sensors for clinical use, emphasizing the critical need for interdisciplinary collaboration between medical and engineering professionals. Overall, this review would serve as an important reference for the future direction of sensor devices in clinical use.

8.
Poult Sci ; 102(11): 103010, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37633080

RESUMO

The present study was performed to explore the effects of dietary supplementation of hydrolyzed gallotannin (HGT) on intestinal physical barrier, immune function and microbiota structure in yellow-feather broilers. A total of 288 male yellow-feather broilers were randomly allocated to 4 diet treatments: the basal diet (CON) and 3 diets supplemented with 150, 300, and 450 mg/kg HGT for 63 d, respectively, with 6 replicates per treatment and 12 birds per replicate. The findings demonstrated that 300 or 450 mg/kg HGT addition enhanced the expression of duodenal occludin (OCLN) and tight junction protein1 (TJP-1) genes of birds at 21 d of age, and the expression of duodenal and ileal OCLN gene in 63-day-old broilers was upregulated due to 450 mg/kg HGT treatment (P < 0.05). The dietary supplementation of 150 mg/kg HGT strengthened the expression of duodenal IL-6 and IL-4 genes and ileal IL-4 gene of 21-day-old broilers, whereas the expression of jejunal IL1B and IL-6 genes in birds at 63 d of age weakened because of 300 or 450 mg/kg HGT addition (P < 0.05). As for microbial community, the HGT addition altered the cecal microbiota structure of birds at 21 d of age based on analysis of similarities (ANOSIM) test and 450 mg/kg HGT treatment increased the relative abundance of norank Eubacterium coprostanoligenes group at 21 d of age and unclassified Lachnospiraceae at 63 d of age (P < 0.05). In short, diet supplemented with 300 to 450 mg/kg HGT may be the optimal for yellow-feather broilers to enhance intestinal barrier function. Altogether, our study clarified the regulatory role of HGT in broiler intestinal health in earnest, but the underlying mechanism is still unclear. Hence, more research is needed to carry out until the application of HGT as a new functional additive in broiler production.

9.
Poult Sci ; 102(10): 102844, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37579647

RESUMO

Exhaustive understanding of intestinal physiological characteristics is the critical precondition for the improvement of intestinal health and growth performance of yellow-feather broilers (YFB). As a vital part of gastrointestinal tract, the symbiotic, complex, and variable microbiota have a profound effect on the nutrition, immunity, health, and production of broilers. Hence, the development status of proventriculus, jejunum, and cecum, and spatial heterogeneity of bacterial community in crop, proventriculus, gizzard, jejunum, cecum, and rectum of adult YFB were detected in our study. The results revealed that proventriculus, jejunum, and cecum of broilers are well-developed based on morphological observation. The Chao and Shannon indexes in cecum and rectum are notably higher than other sections and their microbiota structure is also distinct from foregut. Firmicutes and Lactobacillus are the predominant phylum and genus in all gastrointestinal sections, respectively. As feature species of crop, Lactobacillus spp. mainly settle in foregut, whereas some Clostridia species (unclassified Lachnospiraceae, Faecalibacterium, Romboutsia and so on) are characteristic and more abundant in cecum and rectum. Interestingly, there are 2 Ruminococcus torques strains positively and negatively correlated with cecum development, respectively. In a whole, our findings reveal the specialized digestive physiology and regional distribution of intestinal microbiota in YFB, which provides a reference for the future study on the improvement of growth performance and intestinal development through microbiota manipulation in yellow-feather broilers.


Assuntos
Microbioma Gastrointestinal , Animais , Galinhas/microbiologia , Plumas , Trato Gastrointestinal/microbiologia , Ceco/microbiologia , Lactobacillus , Ração Animal , Dieta/veterinária
10.
Behav Brain Res ; 452: 114564, 2023 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-37459956

RESUMO

Significant sex differences are found in songbirds' song control nuclei and their controlled song behaviors. To elucidate the underlying mechanisms, we explored the role of Notch1 during the development of the high vocal centre (HVC) and song learning in zebra finch. Our study first found that Notch1 positive cells were distributed in HVC with female-biased densities at posthatching day (PHD) 15, but male-biased at PHD 45 and adult. There were about 60 putative oestrogen-responsive elements within 2.5 kb upstream of Notch1, and Notch1 mRNA in the explants that contained the developing male HVC was significantly increased after estrogen addition into the cultured medium for 48 h. After injecting Notch1-interfering lentivirus into the male or female HVC at PHD 15, cell proliferation was significantly promoted in the ventricle zone overlying the HVC at PHD 23. In addition, neuronal differentiation towards Hu+ /BrdU+ at PHD 31, mature neurons (NeuN+/BrdU+) including those projecting to RA in HVC and the sizes of HVC and RA at adult increased significantly after Notch1-interfering lentiviruses were injected into the male HVC at PHD 15. However, the above measurements decreased, following the injection of the lentiviruses expressing Notch intracellular domain (NICD). Finally, the repeat numbers of syllables 'b' or 'c' of learned songs changed after the injection of Notch1-interfering or NICD-expressing lentiviruses into the HVC at PHD15. Our study suggests that Notch1 is related to the development of HVC and song learning in the zebra finch.


Assuntos
Tentilhões , Centro Vocal Superior , Animais , Feminino , Masculino , Centro Vocal Superior/fisiologia , Bromodesoxiuridina , Vocalização Animal/fisiologia , Tentilhões/fisiologia , Diferenciação Celular
11.
12.
Br J Neurosurg ; 35(5): 611-618, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34002649

RESUMO

OBJECTIVES: We reviewed our institutional experience during a 10-year period for improvement of safety and efficacy of stereotactic biopsy procedures. METHODS: We performed a retrospective review of inpatient summaries, stereotactic worksheets and radiologic investigations of 208 consecutive patients, who underwent MRI-guided stereotactic biopsies between March 2010 and March 2020. RESULTS: The overall diagnostic yield was 96.2%. CT-confirmed intracranial hemorrhage occurred in 17 patients (8.2%), and the overall mortality rate was 0.5%. Combined MRS and PWI helped target selection in 27 cases (13.0%), the diagnostic yield was 100%. The results of the regression analysis revealed that non-diagnostic biopsy specimen significantly correlated with the cystic trait (p<.01) and edema of lesions (p<.05). Enhancement (p<.01) is shown to be an important factor for obtaining a diagnostic biopsy. Furthermore, the edema trait of lesions (p<.01) showed the important factors of hemorrhage. CONCLUSIONS: The radiological features of lesions and use of the most suitable MRI sequences during biopsy planning are recommended ways to improve the diagnostic yield and safety of this technique.


Assuntos
Neoplasias Encefálicas , Técnicas Estereotáxicas , Biópsia , Encéfalo/diagnóstico por imagem , Encéfalo/cirurgia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/cirurgia , Humanos , Biópsia Guiada por Imagem , Imageamento por Ressonância Magnética , Estudos Retrospectivos
13.
Sci Rep ; 10(1): 8130, 2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32424160

RESUMO

Huntington's disease (HD) is caused by CAG repeat expansion in the huntingtin gene. The expanded polyglutamine (polyQ) repeat of the encoded protein leads to protein misfolding and aggregation, resulting in increased neuronal cell death. DNAJ co-chaperones play a crucial role in transferring misfolded/unfolded proteins to HSP70 chaperones, which play an essential role for protein folding. Here, we investigated the effect of knock out (KO) of three individual DNAJ genes in HEK293 cells expressing polyglutamine74exon1 huntingtin (polyQ74htt). Flourescence microscopy analysis revealed that KO of DNAJB6 resulted in a 5-fold increase in polyQ74htt aggregation and that DNAJA1 KO resulted in a 4-fold decrease of polyQ74htt aggregation. KO of DNAJB1 did not change the propensity of polyQ74htt to aggregate in cells. These findings where confirmed both by fluorescence microscopy analysis and filter trap assay (FTA). DNAJB6 KO cells displayed an increased rate of cell death as assessed by trypan blue exclusion and propidium iodide (PI) uptake assays. These results demonstrate that the DNAJ proteins DNAJA1 and DNAJB6 can modulate polyQ aggregation in opposite manners, and thus that fine-tuning the cellular levels of DNAJ proteins is critical for suppression of polyQ aggregation and cell survival.


Assuntos
Proteínas de Choque Térmico HSP40/metabolismo , Chaperonas Moleculares/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Peptídeos/química , Peptídeos/metabolismo , Células HEK293 , Proteínas de Choque Térmico HSP40/genética , Humanos , Proteína Huntingtina/química , Proteína Huntingtina/genética , Proteína Huntingtina/metabolismo , Doença de Huntington/genética , Doença de Huntington/metabolismo , Chaperonas Moleculares/genética , Proteínas do Tecido Nervoso/genética , Agregados Proteicos
14.
Curr Med Chem ; 27(16): 2681-2703, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31622196

RESUMO

Natural hydrogels are three-dimensional (3D) water-retaining materials with a skeleton consisting of natural polymers, their derivatives or mixtures. Natural hydrogels can provide sustained or controlled drug release and possess some unique properties of natural polymers, such as biodegradability, biocompatibility and some additional functions, such as CD44 targeting of hyaluronic acid. Natural hydrogels can be used with photosensitizers (PSs) in photodynamic therapy (PDT) to increase the range of applications. In the current review, the pertinent design variables are discussed along with a description of the categories of natural hydrogels available for PDT.


Assuntos
Fotoquimioterapia , Liberação Controlada de Fármacos , Ácido Hialurônico , Hidrogéis , Fármacos Fotossensibilizantes
15.
Food Funct ; 9(8): 4376-4383, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30051131

RESUMO

Enteromorpha prolifera is an edible alga and previous studies have indicated that E. prolifera polysaccharide (EP) attenuates non-alcoholic fatty liver disease (NAFLD) in high-fat diet rats. Hydrogen sulfide (H2S) has recently been found to exert many physiological effects. The purpose of this study was to evaluate whether EP prevents NAFLD via regulation of H2S production. EP was orally administered to high-fat diet rats for 5 weeks. Treatment with EP (200 mg per kg body weight per d) significantly increased the serum H2S level and reduced the serum triglyceride level (p < 0.05) in rats fed a high-fat diet. These effects were similar to those observed with NaHS, a H2S donor. Real-time PCR and western blotting analysis revealed that EP significantly upregulated hepatic mRNA and protein expression of cystathionine-ß-synthase, which is the enzyme responsible for H2S production. These results indicate that EP decreases the serum TG level by increasing H2S production, suggesting that EP may be beneficial for the treatment of NAFLD and may reduce the risk of cardiovascular disease.


Assuntos
Sulfeto de Hidrogênio/sangue , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Extratos Vegetais/administração & dosagem , Polissacarídeos/administração & dosagem , Ulva/química , Verduras/química , Animais , Cistationina beta-Sintase/metabolismo , Dieta Hiperlipídica/efeitos adversos , Feminino , Humanos , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/etiologia , Extratos Vegetais/química , Polissacarídeos/química , Ratos , Ratos Sprague-Dawley , Triglicerídeos/sangue
16.
J Chem Phys ; 141(6): 064311, 2014 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-25134575

RESUMO

The dynamics of the (18)O((3)P) + (32)O2 isotope exchange reaction were studied using crossed atomic and molecular beams at collision energies (E(coll)) of 5.7 and 7.3 kcal/mol, and experimental results were compared with quantum statistical (QS) and quasi-classical trajectory (QCT) calculations on the O3(X(1)A') potential energy surface (PES) of Babikov et al. [D. Babikov, B. K. Kendrick, R. B. Walker, R. T. Pack, P. Fleurat-Lesard, and R. Schinke, J. Chem. Phys. 118, 6298 (2003)]. In both QS and QCT calculations, agreement with experiment was markedly improved by performing calculations with the experimental distribution of collision energies instead of fixed at the average collision energy. At both collision energies, the scattering displayed a forward bias, with a smaller bias at the lower E(coll). Comparisons with the QS calculations suggest that (34)O2 is produced with a non-statistical rovibrational distribution that is hotter than predicted, and the discrepancy is larger at the lower E(coll). If this underprediction of rovibrational excitation by the QS method is not due to PES errors and/or to non-adiabatic effects not included in the calculations, then this collision energy dependence is opposite to what might be expected based on collision complex lifetime arguments and opposite to that measured for the forward bias. While the QCT calculations captured the experimental product vibrational energy distribution better than the QS method, the QCT results underpredicted rotationally excited products, overpredicted forward-bias and predicted a trend in the strength of forward-bias with collision energy opposite to that measured, indicating that it does not completely capture the dynamic behavior measured in the experiment. Thus, these results further underscore the need for improvement in theoretical treatments of dynamics on the O3(X(1)A') PES and perhaps of the PES itself in order to better understand and predict non-statistical effects in this reaction and in the formation of ozone (in which the intermediate O3* complex is collisionally stabilized by a third body). The scattering data presented here at two different collision energies provide important benchmarks to guide these improvements.

17.
J Chem Phys ; 139(1): 014306, 2013 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-23822302

RESUMO

The gas-phase reaction dynamics for the C((1)D) + H2(D2) → CH(D) + H(D) is investigated on a new ab initio potential energy surface (PES). The initial state-specified integral cross section and rate constant are obtained using the Chebyshev real wave packet method; the low-lying vibrational energy levels are also calculated on this new PES using Lanczos algorithm. The vibrational energy levels agree well with the experimental data and are superior to Bussery-Honvault-Honvault-Launay [B. Bussery-Honvault, P. Honvault, and J.-M. Launay, J. Chem. Phys. 115, 10701 (2001)] surfaces' results. The reaction probabilities display oscillatory structure due to the numerous long-lived resonances supported by the deep potential well. The rate constants show nearly temperature independence at the range of 100 K-350 K.

18.
J Am Chem Soc ; 129(10): 2866-70, 2007 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-17300194

RESUMO

The recombination of oxygen atoms with oxygen molecules to form ozone exhibits several strange chemical characteristics, including unusually large differences in formation rate coefficients when different isotopes of oxygen participate. Purely statistical chemical reaction rate theories cannot describe these isotope effects, suggesting that reaction dynamics must play an important role. We investigated the dynamics of the 18O + 32O2 --> O3(*) --> 16O + 34O2 isotope exchange reaction (which proceeds on the same potential energy surface as ozone formation) using crossed atomic and molecular beams at a collision energy of 7.3 kcal mol(-1), providing the first direct experimental evidence that the dissociation of excited ozone exhibits significant nonstatistical behavior. These results are compared with quantum statistical and quasi-classical trajectory calculations in order to gain insight into the potential energy surface and the dynamics of ozone formation.

19.
Di Yi Jun Yi Da Xue Xue Bao ; 23(12): 1307-9, 2003 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-14678898

RESUMO

OBJECTIVE: To observe the changes in peripheral blood lymphocyte subsets in patients with latent syphilis after treatment, who had persistent positive results of test for rapid plasma reagin (RPR) and remained infectious. METHODS: T-lymphocyte subsets and natural killer (NK) cells in peripheral blood were measured with flow cytometry (FCM) in these 43 patients and 30 normal subjects served as controls. RESULTS: Peripheral blood CD3, CD4 and NK cells exhibited no significant difference between the latent patients and the controls (P>0.05), but CD8 cells were higher in these patients (P<0.05). The treated patients with persistent positive RPR within two years had elevated levels of CD3, CD4 and CD8 lymphocytes (P<0.05), but NK cells appeared to be lowered (P<0.05); in patients with positive RPR for over two years, CD3, CD4 and NK cells were comparable with those in the controls (P>0.05), but CD8 cells was elevated (P<0.05). Patients with RPR positivity within two years had higher CD3 and CD4 lymphocytes, but lower NK cells in comparison with the patients with more than two years' of positivity (P<0.05); CD8 cells were comparable between the two groups (P>0.05). CONCLUSIONS: Cellular immunity imbalance and immune suppression can be present in treated syphilis patients with persistent positive RPR and the risk to transmission, which may lower the host ability to resist and clear Treponema pallidum and is associated with the difficulty in treating syphilis patients and the persistence of positive RPR even after treatment.


Assuntos
Reaginas/sangue , Sífilis/imunologia , Subpopulações de Linfócitos T/imunologia , Adulto , Feminino , Citometria de Fluxo , Humanos , Masculino , Sífilis/tratamento farmacológico
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