RESUMO
Objective: To explore the efficacy of venetoclax-based induction regimen for children with newly diagnosed acute myeloid leukemia (AML). Methods: Children with newly diagnosed AML in Beijing Children's Hospital Affiliated to Capital Medical University and Baoding Hospital Affliliated to Capital Medical University from November 2019 and December 2023 were prospectively included. The patients were divided into DAH group (daunorubicin, cytarabine and homoharringtonine) and VAH group (venetoclax, cytarabine and homoharringtonine) according to induction regimen. The clinical data of the children were collected, the clinical characteristics and induced remission rate between the two groups were compared, and multivariate logistic regression was used to analyze the related factors affecting the induced remission rate. Results: A total of 135 patients were enrolled, including 96 cases in the DAH group (54 males and 42 females), aged [M (Q1, Q3)] 6.4 (3.9, 11.6) years and 39 cases in the VAH group (26 males and 13 females), aged 8.0 (6.2, 13.2) years. Among patients initially diagnosed with low-medium risk AML, the morphologic complete remission rates were 94.7% (18/19) in the VAH group and 84.4% (38/45) in the DAH group, respectively, and the negativity conversion rates of minirnal residual disease (MRD) were 57.9% (11/19) and 46.7% (21/45), respectively, with no statistically difference (all P>0.05). Among patients initially diagnoised with high-risk AML, the morphologic complete remission rates in the VAH group was higher than that in the DAH group [95.0% (19/20) vs 70.6% (36/51), P=0.027], and negativity conversion rates of MRD were 45.0% (9/20) and 33.3% (17/51), respectively, with no statistically difference (P=0.359). The induction regimen (venetoclax, cytarabine and homoharringtonin) was beneficial to morphological remission (OR=0.126, 95%CI: 0.025-0.629). FLT3 mutation was not conducive to morphological remission (OR=5.832, 95%CI: 1.778-19.124) and negative MRD (OR=4.166, 95%CI: 1.396-12.433). Conclusion: Venetoclax-based induction regimen is more effective than traditional chemotherapy regimen for newly diagnosed pediatric AML.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Compostos Bicíclicos Heterocíclicos com Pontes , Citarabina , Leucemia Mieloide Aguda , Sulfonamidas , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Criança , Masculino , Feminino , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Sulfonamidas/administração & dosagem , Sulfonamidas/uso terapêutico , Citarabina/administração & dosagem , Citarabina/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Pré-Escolar , Indução de Remissão , Adolescente , Daunorrubicina/administração & dosagem , Daunorrubicina/uso terapêutico , Quimioterapia de Indução , Mepesuccinato de Omacetaxina/administração & dosagem , Mepesuccinato de Omacetaxina/uso terapêutico , Estudos ProspectivosRESUMO
The generation of low emittance electron beams from laser-driven wakefields is crucial for the development of compact x-ray sources. Here, we show new results for the injection and acceleration of quasimonoenergetic electron beams in low amplitude wakefields experimentally and using simulations. This is achieved by using two laser pulses decoupling the wakefield generation from the electron trapping via ionization injection. The injection duration, which affects the beam charge and energy spread, is found to be tunable by adjusting the relative pulse delay. By changing the polarization of the injector pulse, reducing the ionization volume, the electron spectra of the accelerated electron bunches are improved.
RESUMO
AIM: To determine whether computed tomography (CT) texture analysis parameters can be used as quantitative biomarkers to help differentiate giant cell tumour of bones (GCTs), primary aneurysmal bone cysts (PABCs), and aneurysmal bone cysts (ABCs) secondary to giant cell tumours of bone (GABCs). MATERIALS AND METHODS: One hundred and seven patients with 63 GCTs, 31 PABCs, and 13 GABCs were analysed retrospectively. All patients underwent preoperative CT. Two radiologists independently evaluated the qualitative features of the CT images and extracted texture parameters. Patient demographics, qualitative features, and texture parameters among GCTs, PABCs, and GABCs were compared statistically. Differences in these parameters between ABCs and GCTs were also assessed. ROC curves were obtained to determine optimal parameter values. RESULTS: The best preoperative CT parameters to differentiate GCTs, PABCs, and GABCs included one qualitative feature (location around the knee) and four texture parameters (95th percentile, maximum intensity, skewness, and kurtosis). Age and three texture parameters (5th percentile, inhomogeneity, and kurtosis) enabled statistically significant differentiation between GCTs and ABCs. Combination of the above four parameters generated the largest area under the ROC curve (AUC) for the differentiation of GCTs and ABCs. CONCLUSION: CT texture analysis parameters can be used as quantitative biomarkers for preoperative differentiation among GCTs, PABCs, and GABCs.
Assuntos
Cistos Ósseos Aneurismáticos , Neoplasias Ósseas , Tumor de Células Gigantes do Osso , Humanos , Tumor de Células Gigantes do Osso/complicações , Tumor de Células Gigantes do Osso/diagnóstico por imagem , Cistos Ósseos Aneurismáticos/complicações , Cistos Ósseos Aneurismáticos/diagnóstico por imagem , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos , Biomarcadores , Neoplasias Ósseas/patologiaRESUMO
Objective: To explore the relationship between white matter lesions and clinical features and response of cerebral spinal fluid (CSF) tap test in patients with idiopathic normal pressure hydrocephalus(iNPH). Methods: Possible iNPH patients were enrolled from outpatients and inpatients in Peking Union Medical College Hospital between 2014 and 2019. All patients underwent detailed neuropsychological and walking assessments, CSF tap test, as well as head magnetic resonance imaging. The Fazekas score of white matter lesions, the fractional anisotropy (FA)and mean diffusivity (MD) values of regions of interest by means ofdiffusion tensor imaging (DTI) were compared between CSF tap test positive and negative response groups. The correlation between DTI parameters and clinical characteristics was analyzed. Results: Forty-three patients (29 male and 14 female, age range: 52-79 years] wererecruited.Compared with the negative group, patients in the positive group tended to have higher Fazekas score of periventricular white matter(U=108.00, P=0.03), higher MD value of the region near anterior horn of left lateral ventricles[(1.14±0.27)×10-9mm2/s vs (0.85±0.08) ×10-9mm2/s, P=0.003], lower FA value of the region near anterior horn of the right lateral ventricles[(0.20±0.07)vs(0.27±0.09), P=0.058], and higher MD value near the posterior horn of right lateral ventricle [(1.17±0.34)×10-9mm2/s vs (0.95±0.01)×10-9mm2/s, P=0.003]. FA and MD were significantly correlated with motor function, cognitive and functional scores, and iNPH grading scale (iNPHGS) scores(all P<0.05). Conclusions: The white matter lesions might be one of the pathogeneses of lNPH and apathological changewhich can be reversed by CSF drainage. More white matter lesions should not be the contraindication of CSF drainage surgery.
Assuntos
Hidrocefalia de Pressão Normal , Substância Branca , Idoso , Anisotropia , Imagem de Tensor de Difusão/métodos , Feminino , Humanos , Hidrocefalia de Pressão Normal/cirurgia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Substância Branca/patologiaRESUMO
AIM: To characterize the bacterial community present in the extraradicular biofilm and periradicular lesions associated with persistent apical periodontitis. METHODOLOGY: Eighteen adult patients who presented with persistent periradicular lesions after root canal treatment and scheduled for endodontic surgery were selected. During surgery, extraradicular samples of biofilms and periradicular lesions were collected. Ten pairs of periradicular lesions and extraradicular biofilm samples were randomly selected for ribosomal 16S rRNA cloning and sequencing. A Wilcoxon's rank-sum test was used to compare total bacterial counts and the levels of individual genera and species between the two groups (P < 0.05). RESULTS: Overall, seventy-three phylotypes belonging to six different phyla were identified from 1000 sequenced clones. Mogibacterium timidum, Streptococcus intermedius and Enterococcus faecalis predominated in both extraradicular biofilm and periapical lesions. Propionibacterium propionicus, Abiotrophia adiacens, Peptostreptococcus prevotii, Campylobacter gracilis and Pseudomonas aeruginosa were found in significantly higher levels in the extraradicular biofilm than periapical lesions, whilst Parvimonas micra and Atopobium rimae were more abundant in periapical lesions (P < 0.05). CONCLUSIONS: The microbial profile of extraradicular biofilms differed from periapical lesions, indicating the presence of diverse bacterial populations in these regions. Several genera and species were significantly associated with the formation of extraradicular biofilms.
Assuntos
Periodontite Periapical , Actinobacteria , Adulto , Biofilmes , Campylobacter , Carnobacteriaceae , Clostridiales , Cavidade Pulpar , Firmicutes , Humanos , RNA Ribossômico 16S/genéticaRESUMO
Objective: To investigate the differential expression of long non-coding RNA (lncRNA) in placental tissues of women with preeclampsia (PE) and the effect of MIR210HG on the biological function of HTR8/SVneo cells. Methods: A total of 39 cases of PE women (PE group) and 39 cases of normal pregnant women (CTL group) admitted to the Affiliated Hospital of Qingdao University from July 2018 to July 2019 were collected. (1) Transcriptome sequencing (RNA-seq) was used to analyze the differentially expressed lncRNAs in the placental tissues of the two groups. (2) The expression level of MIR210HG, one of the differentially expressed lncRNAs, in the placental tissues of the two groups was detected by real-time quantitative PCR. And the correlations between the expression level of MIR210HG and systolic blood pressure, diastolic blood pressure and neonatal birth weight were analyzed. (3) The constructed small interfering RNA and negative control (NC) RNA were transfected into the HTR8/SVneo cells. The cells were divided into MIR210HG knockdown (KD) group and NC group. The effects of living cell counting (CCK-8) and transwell assay on the proliferation and migration of HTR8/SVneo cells were detected. (4) RNA interacting with MIR210HG was predicted using the Encyclopedia of RNA Interactomes (ENCORI) database. Gene Ontology (GO) functional annotation, Kyoto Encyclopedia of Gene and Genomes (KEGG) and BioCarta pathway enrichment analysis were performed. Results: (1) A total of 26 significantly differentially expressed lncRNAs were found by RNA-seq, among which 21 lncRNAs were up-regulated and 5 lncRNAs were down-regulated. (2) The relative expression level of MIR210HG in the PE group was significantly higher than that in the CTL group (9.30±1.90 and 1.10±0.20, respectively; t=4.425, P<0.01). The relative expression level of MIR210HG had positive linear correlation with systolic blood pressure (r2=0.234, P<0.05) and diastolic blood pressure (r2=0.190, P<0.05), but had a negative linear correlation with newborn birth weight (r2=0.157, P<0.05). (3) Compared with the NC group, the proliferation and migration ability of HTR8/SVneo cells in the KD group were increased (all P<0.05). (4) A total of 38 RNAs that might interact with MIR210HG were predicted by ENCORI database. GO functional annotation analysis showed that MIR210HG might be involved in the functions of 27 pathways, including the regulation of production of molecular mediator of immune response, etc; KEGG pathway analysis showed that MIR210HG might be involved in the function of 8 pathways including allograft rejection, etc; Biocarta pathway analysis showed that MIR210HG may be involved in the functions of 8 pathways, including the eukaryotic initiation factor (eIF) pathway, etc. Conclusion: The expression of MIR210HG is up-regulated in the placental tissue of PE women, and MIR210HG might be a regulator of the biological behavior of trophoblast cells.
Assuntos
Placenta , Pré-Eclâmpsia , RNA Longo não Codificante , Feminino , Humanos , Recém-Nascido , Pré-Eclâmpsia/genética , Gravidez , RNA Longo não Codificante/genética , RNA Interferente Pequeno , TrofoblastosRESUMO
Objective: To examine the early outcome of valve sparing aortic root replacement with reimplantation technique (David procedure) with partial upper sternotomy. Methods: From April 2016 to April 2020, 31 patients underwent valve sparing aortic root replacement under partial upper sternotomy at Vascular Surgery Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. There were 28 males and 3 females, aging (44±13) years (range: 11 to 65 years). Preoperative aortic regurgitation was found greater than moderate in 15 patients, moderate in 6 patients and less than moderate in 10 patients. The diameter of aortic annulus was (26±3) mm (range: 21 to 34 mm), the diameter of aortic sinus was (51±6) mm (range: 41 to 68 mm), the diameter of ascending aorta was (43±8) mm (range: 26 to 62 mm). The preoperative ejection fraction was (65±4) % (range: 59% to 72%) and left ventricular end-diastolic diameter was (55±6) mm (range: 42 to 68 mm). All cases were treated with David â procedure, including simple David procedure in 26 patients, David+ascending aorta and partial aortic arch replacement in 3 patients, David+thoracic endovascular aortic repair in 1 patient, David+stent elephant trunk implantation in 1 patient. Results: The operation time, cardiopulmonary bypass time and aortic cross-clamping time were (330±58) minutes (range: 214 to 481 minutes), (138±23) minutes (range: 106 to 192 minutes) and (108±17) minutes (range: 82 to 154 minutes), respectively. There were no death and serious complications (stroke, myocardial infarction, renal insufficiency, severe infection, etc.). The postoperative drainage volume within 24 hours was (314±145) ml (range: 130 to 830 ml). The intubation time was (14±3) hours (range: 8 to 21 hours), and the ICU time was (M(QR)) 2.1(1.5) days (range: 1.0 to 5.0 days). Eight patients had no blood transfusion, the proportion of red blood cell use was 9.7% (3/31), plasma use was 22.6% (7/31), and platelet use was 71.0% (22/31). The postoperative left ventricular ejection fraction was (62±4)% (range: 54% to 69%), and left ventricular end-diastolic diameter was (48±4) mm (range: 39 to 56 mm). After operation, aortic regurgitation was significantly improved, with no more than moderate regurgitation, small to moderate regurgitation in 3 patients, minor regurgitation in 3 patients, micro regurgitation in 12 patients and no regurgitation in 13 patients. The follow-up period was 3.5(6.1) months (range: 2.0 to 39.0 months). Echocardiographic follow-up data were obtained in 26 cases, including moderate regurgitation in 1 patient, small to moderate regurgitation in 9 patients, minor regurgitation in 5 patients, micro regurgitation in 6 patients and no regurgitation in 5 patients. There were no major adverse cardiovascular events and aortic events during the follow-up period. No patient was reoperated for aortic regurgitation. Conclusion: Valve sparing aortic root replacement under partial upper sternotomy is safe and feasible, and the early result is satisfactory.
Assuntos
Valva Aórtica , Esternotomia , Aorta , Feminino , Humanos , Masculino , Reimplante , Volume Sistólico , Função Ventricular EsquerdaRESUMO
BACKGROUND AND PURPOSE: The role of intracranial steno-occlusive disease in cognitive impairment and dementia is unclear and has not been well studied. METHODS: A total of 32 consecutive patients (13 males, aged 54 ± 12 years) with asymptomatic steno-occlusive middle cerebral artery (MCA) disease, defined as >70% stenosis on maximum intensity projection images or a complete signal loss of MCA trunk on magnetic resonance angiography, and 20 age- and education-matched normal controls (12 males, 60 ± 8 years old) were compared for neuropsychological performance, gray matter volume and neural network analysis. RESULTS: The patient group did not show a significant decrease in gray matter volume or cognitive tests except for their performance on the grooved pegboard test. However, graph analysis of resting-state functional magnetic resonance imaging showed significant decreases in network strength, global efficiency and the clustering coefficient, as well as a longer characteristic path length (P < 0.05). The diffusive decrease pattern was particularly located in interhemispheric connectivity and there was no compensatory hyperconnectivity in any brain regions. CONCLUSION: In asymptomatic steno-occlusive MCA disease, cognition and neural network changes are mismatched and have underlying pathophysiological mechanisms that are different from those of neurodegenerative disease.
Assuntos
Artéria Cerebral Média , Doenças Neurodegenerativas , Adulto , Idoso , Cognição , Feminino , Humanos , Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Redes Neurais de ComputaçãoRESUMO
Objective: To explore the correlation of endothelial microparticles and progression of advanced lung cancer, and its predictive value in therapeutic effect. Methods: The data of patients with advanced lung cancer in the Oncology Department of Frist Medical Center of Chinese PLA General Hospital from October 2018 to May 2019 were collected. Blood routine, lactate dehydrogenase (LDH), tumor markers, and circulating endothelial microparticles (CD105+ EMPs) were measured before treatment. Flow cytometry was used to detect the number of CD105+ EMPs, and multivariate regression analysis was used to study the predict factors of advanced lung cancer progression. Results: A total of 88 patients were recruited in the study, including 60 in the objective response (OR) group and 28 in the disease progression (PD) group. There were no significant differences in gender, age, basic diseases, tumor stage, cancer type and therapeutic intervention between two groups, while there were significant differences in tumor marker, LDH, total microparticles (MPs), and endothelial microparticles (CD105+ EMPs) between two groups (P<0.05). In the multivariate regression analysis, CD105+ EMPs ≥70 events/µl (OR=3.623, 95%CI=1.345~9.761, P=0.011) and LDH (OR=1.008, 95%CI=1.001~1.015, P=0.032) were able to predict the progression of advanced lung cancer. A predictive model of advanced lung cancer progression was established based on the multivariate regression results. The area under the receiver operating characteristic curve (AUC) was 0.729 (95%CI=0.620~0.837, P=0.001), the sensitivity was 32.1%, the specificity was 91.6%, the positive predictive value was 64.2%, and the negative predictive value was 74.3%. Conclusion: Circulating endothelial microparticles are associated with the progression of advanced lung cancer, it combined with LDH can predict the therapeutic effect of advanced lung cancer.
Assuntos
Micropartículas Derivadas de Células , Neoplasias Pulmonares , Progressão da Doença , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/terapia , Prognóstico , Curva ROCRESUMO
Episodic memory, a fundamental component of human cognition, is significantly impaired in autism. We believe we report the first evidence for this problem in the Fmr1-knockout (KO) mouse model of Fragile X syndrome and describe potentially treatable underlying causes. The hippocampus is critical for the formation and use of episodes, with semantic (cue identity) information relayed to the structure via the lateral perforant path (LPP). The unusual form of synaptic plasticity expressed by the LPP (lppLTP) was profoundly impaired in Fmr1-KOs relative to wild-type mice. Two factors contributed to this defect: (i) reduced GluN1 subunit levels in synaptic NMDA receptors and related currents, and (ii) impaired retrograde synaptic signaling by the endocannabinoid 2-arachidonoylglycerol (2-AG). Studies using a novel serial cue paradigm showed that episodic encoding is dependent on both the LPP and the endocannabinoid receptor CB1, and is strikingly impaired in Fmr1-KOs. Enhancing 2-AG signaling rescued both lppLTP and learning in the mutants. Thus, two consequences of the Fragile-X mutation converge on plasticity at one site in hippocampus to prevent encoding of a basic element of cognitive memory. Collectively, the results suggest a clinically plausible approach to treatment.
Assuntos
Síndrome do Cromossomo X Frágil/metabolismo , Hipocampo/metabolismo , Potenciação de Longa Duração/fisiologia , Memória Episódica , Animais , Ácidos Araquidônicos/metabolismo , Discriminação Psicológica/efeitos dos fármacos , Discriminação Psicológica/fisiologia , Modelos Animais de Doenças , Endocanabinoides/metabolismo , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Síndrome do Cromossomo X Frágil/tratamento farmacológico , Síndrome do Cromossomo X Frágil/patologia , Glicerídeos/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Potenciação de Longa Duração/efeitos dos fármacos , Masculino , Camundongos Knockout , Proteínas do Tecido Nervoso/metabolismo , Neurotransmissores/farmacologia , Percepção Olfatória/efeitos dos fármacos , Percepção Olfatória/fisiologia , Técnicas de Patch-Clamp , Receptor CB1 de Canabinoide/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Técnicas de Cultura de TecidosRESUMO
AIMS: The purpose of this experiment was to study the bacterial diversity and predominance of spoilage bacteria in chicken skin at different thermal treatment temperatures (60, 70, 80, 90, 100, 110, 120°C). METHOD AND RESULTS: Bacteria in chicken skin was collected, then propidium monoazide treatment to remove the DNA of dead cell, total DNA was extracted by Tiandz Bacterial DNA Kit, and investigated by high-throughput sequencing of the v3/v4 regions of the 16S rDNA gene. A total of 796 008 high-quality bacterial sequences were obtained for assessing the microbial diversity of chicken skin from seven thermal treatment group and control group. The results showed that the bacterial diversity in chicken skin at 90°C was lowest. And Acinetobacter (25·88%), Clostridium (20·70%), Bacteroides (13·93%) and Myroides (13·13%) were the main flora at 25°C; The Clostridium was dominant genus of the samples heat-treated by 60, 70, 80 and 90°C, the proportion of this genus were up to 64·86, 77·42, 52·22 and 87·30% respectively. The Bacillus was the main flora of the samples heat-treated by 100, 110 and 120°C, and the relative percentages were 39·44, 79·61 and 45·96% respectively. In addition, high-temperature-resistant Serratia was found in chicken skin. CONCLUSIONS: The study revealed that the relationship between thermal treatment temperature and bacterial diversity and dominant spoilage bacteria in chicken skin, which had a strong guiding significance for the control and prediction of micro-organisms in foods. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this paper could provide a theoretical basis for meat products containing chicken skin, including the safe use of chicken skin, determination of sterilization process parameters and selection of preservatives for compounding, which has strong practicality in China.
Assuntos
Bactérias/classificação , Bactérias/isolamento & purificação , Biodiversidade , Temperatura Alta , Produtos da Carne/microbiologia , Pele/microbiologia , Animais , Azidas/química , Bactérias/genética , Galinhas , DNA Bacteriano/química , DNA Bacteriano/genética , Propídio/análogos & derivados , Propídio/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
AIMS: The purpose of this experiment was to study the bacterial diversity and predominance of spoilage bacteria in chicken skin at different storage temperatures (4, 25 and 37°C). METHODS AND RESULTS: The total bacteria in chicken skin were collected, total DNA was extracted by an E. Z. N. A. Bacterial DNA Kit, and the v3-v4 regions of the 16S rDNA gene in the microbiota of the chicken skin were studied using the Illumina Hiseq platform. A total of 91 862 bacterial sequences were obtained for assessing the microbial diversity from chicken skin at three storage temperatures. The results showed that the bacterial diversity in chicken skin at 25°C was the highest, and Pseudomonas was dominant at 4°C, while Acinetobacter and Clostridium were the main flora at 25°C. Clostridium dominated and played a critical role in the chicken skin stored at 37°C. CONCLUSIONS: The effect of temperature on bacterial diversity in chicken skin was significant and the dominant spoilage bacteria were different in chicken skin at different temperatures, which had a strong guiding significance for the control and prediction of micro-organisms in foods. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this article could provide a theoretical basis for meat products containing chicken skin, including the safe use of chicken skin, determination of sterilization process parameters and selection of preservatives for compounding.
Assuntos
Galinhas/microbiologia , Microbiologia de Alimentos , Armazenamento de Alimentos , Pele/microbiologia , Animais , Bactérias/classificação , Bactérias/isolamento & purificação , Temperatura Baixa , Carne/análise , Carne/microbiologiaRESUMO
The cross-Kerr effects between the cavity and the mechanical oscillator in a parity-time symmetric optomechanical system are investigated. It is found that in the double-passive case there appears an asymmetric optomechanically induced transparency (OMIT) spectrum which is composed of a broad absorption peak located around the resonant point and a absorption line at the frequency position mainly determined by the Kerr interaction. The distinctive asymmetry induced by the cross-Kerr coupling is precisely demonstrated by the analytic findings. In the passive-active case, the resonance peaks in the OMIT spectrum are increased with the weak tunnel coupling, which is contrary to that in the double-passive case. When the tunnel coupling is increased up in the strong coupling region, the broad absorption peak and the absorption line in the OMIT spectrum are sequentially changed into the amplification ones, and the central amplification dip is split into two parts due to the normal mode splitting induced by the strong tunnel coupling. This can be used to realize a switching from absorption to amplification by only adjusting the tunnel interaction.
RESUMO
AIM: To evaluate the frequency of dentinal microcracks after ultrasonic removal of fractured files from the middle third of root canals using micro-computed tomography (micro-CT). METHODOLOGY: Eighteen bilaterally matched pairs of human mandibular incisors extracted for periodontal reasons were included. The matched pairs of teeth were then divided into a control group and an experimental group, with one member of each pair assigned to each group. In the control group, the canals were instrumented using the ProTaper Next (PTN) system. In the experimental group, size 20 K-files were fractured in the middle third of the root canals, followed by their ultrasonic removal. Subsequently, the canals were instrumented with the PTN system. All teeth were scanned using high-resolution micro-CT before (preoperative) and after (intraoperative) file removal and after (postoperative) root canal preparation. Pre-, intra-, and postoperative cross-sectional images of the roots were screened to identify the presence of dentinal defects. Two experienced observers evaluated the images twice in a blinded manner. The incidence of dentinal microcracks was noted and statistically analysed using Fisher's exact and McNemar's tests (P = 0.05), with the root cross-section and the tooth root as the units of analysis, respectively. RESULTS: All fractured files in the experimental group were removed successfully. New microcracks were detected in 0.56% (93/16 472) cross-sections (8/18 specimens) generated after file removal in the experimental group. These microcracks were detected 4-6 mm below the root canal orifice and exhibited a width and length of 12-36 µm and 48-72 µm, respectively. They did not disappear or propagate after canal preparation. No new dentinal microcracks were observed in the control group. There was a significant difference in the incidence of new microcracks between the two groups (P < 0.05). CONCLUSIONS: Ultrasonic removal of fractured files from root canals resulted in the formation of short microcracks in a small number of cross-sections in approximately half the specimens. Further studies are necessary to determine the cause and consequences of this finding.
Assuntos
Cavidade Pulpar/lesões , Dentina/lesões , Obturação do Canal Radicular/métodos , Fraturas dos Dentes/cirurgia , Cavidade Pulpar/diagnóstico por imagem , Dentina/diagnóstico por imagem , Humanos , Radiografia Dentária , Fraturas dos Dentes/diagnóstico por imagem , Ultrassom/métodos , Microtomografia por Raio-XRESUMO
OBJECTIVE: To compare the effects of autoclave on surface microstructure and cyclic fatigue resistance of K3XF and K3. METHODS: Forty-eight size 25, 0.06 taper 25 mm-long K3XF or K3 were randomly divided into 4 groups (n=12). The instruments from group 1 were not autoclaved, and the groups 2 to 4 underwent autoclave for 10 cycles, 20 cycles, and 30 cycles, respectively. The surface microstructure of two instruments randomly selected from each group was observed using scanning electron microscope (SEM). The remaining 10 instruments were submitted to the cyclic fatigue test by using a simulated metal root canal with curvature of 60° and radius 3.5 mm. The time till fracture was recorded, the number of cyclic fatigue (NCF) calculated, the fragment length evaluated, and the topographic features were analyzed using SEM. The data were analyzed using the two-way ANOVA analysis by SAS 9.3 software at a significance level of P<0.05. RESULTS: SEM observation identified rough features on the surface of K3XF with micropores existing evenly. K3 was characterized by machining grooves, which located specifically in the flute, leaving a smooth cutting edge. After autoclave, SEM observation indicated that the micropores in the surface of K3XF became larger and more, whereas the machining grooves in the surface of K3 were squeezed, out of shape and flaking. As far as the NCF was concerned, new K3XF was 210±59, and no significant difference was found after 10, 20, and 30 cycles of autoclave for K3XF, values being 178±37, 208±48, and 227±43, respectively (P>0.05). For K3, the new one was 145±38, and no significant difference in NCF was demonstrated after 10 and 20 cycles of autoclave, with the values of 128±43 and 124±46, respectively (P>0.05). However, after 30 cycles of autoclave of K3, significant increase to 216±38 was identified (P<0.05). Topographic features demonstrated typical cyclic fatigue for all the groups. CONCLUSION: The surface roughness of K3XF was increased after autoclave, while the cyclic resistance remained stable after up to 30 cycles.
Assuntos
Instrumentos Odontológicos , Desinfecção , Preparo de Canal Radicular , Ligas Dentárias , Falha de Equipamento , Temperatura Alta , Teste de Materiais , Níquel , Preparo de Canal Radicular/instrumentação , TitânioRESUMO
Objective: To characterize the brain functional changes of amyotrophic lateral sclerosis (ALS) patients with various levels of cognitive impairment as measured by resting-state functional MRI (RS-fMRI). Methods: From September 2013 to March 2017, a total of 55 patients diagnosed with ALS in Peking Union Medical College Hospital and 20 healthy controls (HCs) were included in this study, and all participants underwent neuropsychological assessments and diffusion tensor imaging scans. According to their cognitive performance, ALS patients were further subclassified into ALS with normal cognition (ALS-Cn, n=27), those with cognitive impairment (ALS-Ci, n=17) and ALS-FTD (n=11). Comparisons of fractional amplitude of low frequency fluctuation (fALFF) value and regional homogeneity (ReHo) value were conducted among the 4 subgroups. Results: The fALFF showed significant differences in bilateral frontal lobe, left temporal lobe and cingulate gyrus, (P<0.001, uncorrected) and the ReHo showed significant differences in left frontal lobe, right temporal lobe and left cingulate gyrus (P<0.001, FDR corrected). The differences mainly stemmed from that patients with ALS-FTD showed decreased fALFF and ReHo in these areas when compared to the other three groups, especially in relation to HCs, mainly locating in left prefrontal lobe and anterior cingulate cortex. The whole-brain comparisons of fALFF and ReHo between ALS-Ci, ALS-Cn and HCs revealed no significant difference (P<0.001, uncorrected). Conclusion: Hypoactivities are detected in extramotor areas in patients with ALS-FTD. RS-fMRI is helpful in investigating the pathophysiologic mechanism of cognitive impairment in ALS.
Assuntos
Esclerose Lateral Amiotrófica , Encéfalo , Disfunção Cognitiva , Imagem de Tensor de Difusão , Humanos , Imageamento por Ressonância MagnéticaRESUMO
Objective: To explore the role of MRI in the pre-operative diagnosis and classification of oblique vaginal septum syndrome (OVSS) . Methods: A retrospective analysis of the clinical records and pre-operative MRI images of 19 patients with surgery proved OVSS was carried out. Two experienced radiologists reviewed the pre-operative pelvic MRI of the 19 patients in consensus blind to the surgery results. Characteristics including malformations of the uterus, cervix and vagina, the diagnosis of the disorder and classification were evaluated. Pre-operative MRI diagnosis and classification were correlated with surgical findings. Results: Mean age of onset of symptoms for the 19 patients was 15 years (ranged 9-25 years) , and mean age of menarche was 12 years. Ten patients suffered from dysmenorrhea or lower abdominal pain, 5 patients complained of vaginal discharge, 3 patients had a history of irregular menstruation, 1 patient suffered from primary infertility. All 19 patients showed uteri didelphys. Eighteen patients showed vaginal oblique septum.One patient showed cervical atresia.MRI was completely correlated with the surgery in the pre-operative diagnosis of OVSS. MRI classification was in line with surgery in 17 patients, including 9 patients with imperforate septum (typeâ ) , 6 patients with perforate septum (type â ¡) , 1 patient with imperforate septum and cervical fistula (type â ¢) , and another one with cervical agenesis (type â £) . One case of type â ¡ was misdiagnosed as type â , another one of type â was misdiagnosed as type â ¢. Pre-operative MRI classification was correlated with surgery in 17 out of 19 patients. Conclusion: Pre-operative MRI allows excellent manifestation and accurate diagnosis of OVSS, and could also facilitate the evaluation of the classification.
Assuntos
Imageamento por Ressonância Magnética , Pelve/diagnóstico por imagem , Anormalidades Urogenitais/classificação , Anormalidades Urogenitais/diagnóstico por imagem , Vagina/anormalidades , Dor Abdominal/etiologia , Adolescente , Adulto , Dismenorreia/etiologia , Feminino , Humanos , Distúrbios Menstruais , Estudos Retrospectivos , Anormalidades Urogenitais/cirurgia , Doenças do Colo do Útero , Vagina/cirurgia , Descarga Vaginal , Adulto JovemRESUMO
Asthma is a highly prevalent chronic allergic inflammatory disease of the airways affecting people worldwide. House dust mite (HDM) is the most common allergen implicated in human allergic asthma. HDM-induced allergic responses are thought to depend upon activation of pathways involving Toll-like receptors and their adaptor protein myeloid differentiation factor 88 (MyD88). We sought here to determine the role of MyD88 in myeloid and type II lung epithelial cells in the development of asthma-like allergic disease using a mouse model. Repeated exposure to HDM caused allergic responses in control mice characterized by influx of eosinophils into the bronchoalveolar space and lung tissue, lung pathology and mucus production and protein leak into bronchoalveolar lavage fluid. All these responses were abrogated in mice with a general deficiency of MyD88 but unaltered in mice with MyD88 deficiency, specifically in myeloid or type II lung epithelial cells. We conclude that cells other than myeloid or type II lung epithelial cells are responsible for MyD88-dependent HDM-induced allergic airway inflammation.
Assuntos
Asma/imunologia , Células Epiteliais/imunologia , Hipersensibilidade/imunologia , Células Mieloides/fisiologia , Fator 88 de Diferenciação Mieloide/metabolismo , Pneumonia/imunologia , Pyroglyphidae/imunologia , Animais , Antígenos de Dermatophagoides/imunologia , Movimento Celular , Células Epiteliais/patologia , Humanos , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genéticaRESUMO
We consider the probe absorption properties in a mechanically coupled optomechanical system in which the two coupled nanomechanical oscillators are driven by the time-dependent forces, respectively. It is found that the mechanical interaction splits the transparency window for a usual single-mode optomechanical system into two parts and then leads to appearance of the double optomechanically induced transparency. The distance between the two transparency positions (the frequency for the maximal transparency) is determined by the mechanical interaction amplitude. This can be explained by using optomechanical dressed-mode picture which is analogue to the interacting dark resonances in coherent atoms. When the mechanical resonators are driven by the external forces, the transparencies in the double-transparency spectrum can be increased into amplifications or be suppressed by tuning the amplitude of the forces. Additionally, it is shown that the double transparencies or the amplifications oscillate with the initial phases of the forces with a period of 2π. These investigations will be useful for more flexible controllability of multi-channel optical communication based on the optomechanical systems.
RESUMO
We apply active feedback optimization methods to pyroelectric measurements of a THz signal generated by four wave mixing in air using 1 mJ to 12 mJ, 35 fs laser pulses operating at 12 kHz repetition rate. A genetic algorithm, using the THz signal as a figure of merit, determines the voltage settings to a deformable mirror and results in up to a 6 fold improvement in the THz signal compared with settings optimized for the best focus. It is possible to optimize for different THz generation processes using this technique.