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Current concepts on osteonecrosis of the femoral head 被引量:96
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作者 Joaquin Moya-Angeler Arianna L Gianakos +2 位作者 Jordan C villa Amelia Ni Joseph M Lane 《World Journal of Orthopedics》 2015年第8期590-601,共12页
It is estimated that 20000 to 30000 new patients are diagnosed with osteonecrosis annually accounting for approximately 10% of the 250000 total hip arthroplasties done annually in the United States. Thelack of level 1... It is estimated that 20000 to 30000 new patients are diagnosed with osteonecrosis annually accounting for approximately 10% of the 250000 total hip arthroplasties done annually in the United States. Thelack of level 1 evidence in the literature makes it difficult to identify optimal treatment protocols to manage patients with pre-collapse avascular necrosis of the femoral head, and early intervention prior to collapse is critical to successful outcomes in joint preserving procedures. There have been a variety of traumatic and atraumatic factors that have been identified as risk factors for osteonecrosis, but the etiology and pathogenesis still remains unclear. Current osteonecrosis diagnosis is dependent upon plain anteroposterior and frog-leg lateral radiographs of the hip, followed by magnetic resonance imaging(MRI). Generally, the first radiographic changes seen by radiograph will be cystic and sclerotic changes in the femoral head. Although the diagnosis may be made by radiograph, plain radiographs are generally insufficient for early diagnosis, therefore MRI is considered the most accurate benchmark. Treatment options include pharmacologic agents such as bisphosphonates and statins, biophysical treatments, as well as joint-preserving and joint-replacing surgeries. the surgical treatment of osteonecrosis of the femoral head can be divided into two major branches: femoral head sparing procedures(FHSP) and femoral head replacement procedures(FHRP). In general, FHSP are indicated at pre-collapse stages with minimal symptoms whereas FHRP are preferred at post-collapse symptomatic stages. It is difficult to know whether any treatment modality changes the natural history of core decompression since the true natural history of core decompression has not been delineated. 展开更多
关键词 OSTEONECROSIS FEMORAL head CONSERVATIVE treatment Core DECOMPRESSION Stem cells Total HIP ARTHROPLASTY
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Small bowel capsule endoscopy in 2007:Indications,risks and limitations 被引量:30
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作者 Emanuele Rondonotti Federica villa +2 位作者 Chris JJ Mulder Maarten AJM Jacobs Roberto de Franchis 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第46期6140-6149,共10页
Capsule endoscopy has revoluzionized the study of the small bowel by providing a reliable method to evaluate, endoscopically, the entire small bowel. In the last six years several papers have been published exploring ... Capsule endoscopy has revoluzionized the study of the small bowel by providing a reliable method to evaluate, endoscopically, the entire small bowel. In the last six years several papers have been published exploring the possible role of this examination in different clinical conditions. At the present time capsule endoscopy is generally recommended as a third examination, after negative bidirectional endoscopy, in patients with obscure gastrointestinal bleeding. A growing body of evidence suggests also an important role for this examination in other clinical conditions such as Crohn's disease, celiac disease, small bowel polyposis syndromes or small bowel tumors. The main complication of this examination is the retention of the device at the site of a previously unknown small bowel stricture. However there are also some other open issues mainly due to technical limitations of this tool (which is not driven from remote control, is unable to take biopsies, to insufflate air, to suck fluids or debris and sometimes to correctly size and locate lesions).The recently developed double balloon enteroscope, owing to its capability to explore a large part of the small bowel and to take targeted biopsies, although being invasive and time consuming, can overcome some limitations of capsule endoscopy. At the present time, in the majority of clinical conditions (i.e. obscure GI bleeding), the winning strategy seems to be to couple these two techniques to explore the small bowel in a painless, safe and complete way (with capsule endoscopy) and to define and treat the lesions identified (with double balloon enteroscopy). 展开更多
关键词 Capsule endoscopy Double balloon
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Long-term albumin infusion improves survival in patients with cirrhosis and ascites: An unblinded randomized trial 被引量:24
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作者 Roberto Giulio Romanelli Giorgio La villa +8 位作者 Giuseppe Barletta Francesco Vizzutti Fabio Lanini Umberto Arena Vieri Boddi Roberto Tarquini Pietro Pantaleo Paolo Gentilini Giacomo Laffi 《World Journal of Gastroenterology》 SCIE CAS CSCD 2006年第9期1403-1407,共5页
AIM: To investigate the effects of long-term albumin administration on survival, recurrence of ascites and onset of other complications. METHODS: One hundred consecutive patients admitted for first-onset ascites wer... AIM: To investigate the effects of long-term albumin administration on survival, recurrence of ascites and onset of other complications. METHODS: One hundred consecutive patients admitted for first-onset ascites were randomized to receive diuretics plus human albumin 25 g/wk in the first year and 25 g every two wk thereafter (group 1) or diuretics alone (group 2). The primary endpoint was survival without liver transplantation. Secondary endpoints were recurrence of ascites and occurrence of other complications. RESULTS: Median follow-up was 84 (2-120) mo. Albu- min-treated patients had significantly greater cumulative survival rate (Breslow test= 7.05, P= 0.0078) and lower probability of ascites recurrence (51% versus 94%, P〈0.0001). Chronic albumin infusion resulted in a mean increase in survival of 16 mo. CONCLUSION: Long-term albumin administration after first-onset ascites significantly improves patients' survival and decreases the risk of ascites recurrence. 展开更多
关键词 Long-term albumin administration after first-onset ascites significantly improves patients' survival and decreases the risk of ascites recurrence.
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Coronary artery anomalies overview: The normal and the abnormal 被引量:15
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作者 Adriana DM villa Eva Sammut +3 位作者 Arjun Nair Ronak Rajani Rodolfo Bonamini Amedeo Chiribiri 《World Journal of Radiology》 CAS 2016年第6期537-555,共19页
The aim of this review is to give a comprehensive and concise overview of coronary embryology and normal coronary anatomy, describe common variants of normal and summarize typical patterns of anomalous coronary artery... The aim of this review is to give a comprehensive and concise overview of coronary embryology and normal coronary anatomy, describe common variants of normal and summarize typical patterns of anomalous coronary artery anatomy. Extensive iconography supports the text, with particular attention to images obtained in vivo using non-invasive imaging. We have divided this article into three groups, according to their frequency in the general population: Normal, normal variant and anomaly. Although congenital coronary artery anomalies are relatively uncommon, they are the second most common cause of sudden cardiac death among young athletes and therefore warrant detailed review. Based on the functional relevance of each abnormality, coronary artery anomalies can be classified as anomalies with obligatory ischemia, without ischemia or with exceptional ischemia. The clinical symptoms may include chest pain, dyspnea, palpitations, syncope, cardiomyopathy, arrhythmia, myocardial infarction and sudden cardiac death. Moreover, it is important to also identify variants and anomalies without clinical relevance in their own right as complications during surgery or angioplasty can occur. 展开更多
关键词 CORONARY ARTERIES ANOMALIES VARIANTS ANATOMY Heart
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Hyperglycemia in acute ischemic stroke: physiopathological and therapeutic complexity 被引量:8
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作者 Federica Ferrari Antonio Moretti Roberto Federico villa 《Neural Regeneration Research》 SCIE CAS CSCD 2022年第2期292-299,共8页
Diabetes mellitus and associated chronic hyperglycemia enhance the risk of acute ischemic stroke and lead to worsened clinical outcome and increased mortality. However, post-stroke hyperglycemia is also present in a n... Diabetes mellitus and associated chronic hyperglycemia enhance the risk of acute ischemic stroke and lead to worsened clinical outcome and increased mortality. However, post-stroke hyperglycemia is also present in a number of non-diabetic patients after acute ischemic stroke, presumably as a stress response. The aim of this review is to summarize the main effects of hyperglycemia when associated to ischemic injury in acute stroke patients, highlighting the clinical and neurological outcomes in these conditions and after the administration of the currently approved pharmacological treatment, i.e. insulin. The disappointing results of the clinical trials on insulin(including the hypoglycemic events) demand a change of strategy based on more focused therapies. Starting from the comprehensive evaluation of the physiopathological alterations occurring in the ischemic brain during hyperglycemic conditions, the effects of various classes of glucose-lowering drugs are reviewed, such as glucose-like peptide-1 receptor agonists, DPP-4 inhibitors and sodium glucose cotransporter 2 inhibitors, in the perspective of overcoming the up-to-date limitations and of evaluating the effectiveness of new potential therapeutic strategies. 展开更多
关键词 acute ischemic stroke diabetes mellitus DPP-4 inhibitor glucose-like peptide-1 receptor agonist HYPERGLYCEMIA HYPOGLYCEMIA insulin PHYSIOPATHOLOGY sodium glucose cotransporter 2 inhibitor
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Exploring the Contribution of Pharmacists in Addressing the Opioid Crisis through Naloxone Prescriptions and Pharmacist-Led Interventions
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作者 Michelle Krey Sophia villa +1 位作者 Nadia Gharibyar Haroon Mesdaq 《Pharmacology & Pharmacy》 2024年第2期27-38,共12页
The opioid epidemic in the United States continues to take the lives of many individuals, with overdoses continuing to rise every year. Naloxone is an opioid antagonist that is efficacious in temporarily reversing opi... The opioid epidemic in the United States continues to take the lives of many individuals, with overdoses continuing to rise every year. Naloxone is an opioid antagonist that is efficacious in temporarily reversing opioid overdoses. Pharmacists play an important role in the accessibility and education of naloxone in both the community and health system settings. Recent efforts, such as co-dispensing naloxone with opioid prescriptions, naloxone training programs, and approval of naloxone to be over-the-counter, have been implemented in hopes to better control the opioid epidemic. Despite the efforts to make naloxone more accessible, there are still some barriers to overcome such as lack of training, cost, stigma, and patient refusal. This review aims to explore the contributions pharmacists have made thus far and define the barriers that still have to be resolved. 展开更多
关键词 NALOXONE Narcan Opioid Crisis Opioid Epidemic PHARMACY PHARMACIST Interventions
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Dispersion Relations in Diffraction in Time
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作者 Salvador Godoy Karen villa 《Applied Mathematics》 2024年第7期464-468,共5页
In agreement with Titchmarsh’s theorem, we prove that dispersion relations are just the Fourier-transform of the identity, g(x′)=±Sgn(x′)g(x′), which defines the property of being a truncated functions at the... In agreement with Titchmarsh’s theorem, we prove that dispersion relations are just the Fourier-transform of the identity, g(x′)=±Sgn(x′)g(x′), which defines the property of being a truncated functions at the origin. On the other hand, we prove that the wave-function of a generalized diffraction in time problem is just the Fourier-transform of a truncated function. Consequently, the existence of dispersion relations for the diffraction in time wave-function follows. We derive these explicit dispersion relations. 展开更多
关键词 Diffraction in Time Dispersion Relations Hilbert Transforms
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Bone remodeling:an operational process ensuring survival and bone mechanical competence 被引量:7
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作者 Simona Bolamperti Isabella villa Alessandro Rubinacci 《Bone Research》 SCIE CAS CSCD 2022年第3期421-439,共19页
Bone remodeling replaces old and damaged bone with new bone through a sequence of cellular events occurring on the same surface without any change in bone shape. It was initially thought that the basic multicellular u... Bone remodeling replaces old and damaged bone with new bone through a sequence of cellular events occurring on the same surface without any change in bone shape. It was initially thought that the basic multicellular unit(BMU) responsible for bone remodeling consists of osteoclasts and osteoblasts functioning through a hierarchical sequence of events organized into distinct stages. However, recent discoveries have indicated that all bone cells participate in BMU formation by interacting both simultaneously and at different differentiation stages with their progenitors, other cells, and bone matrix constituents. Therefore,bone remodeling is currently considered a physiological outcome of continuous cellular operational processes optimized to confer a survival advantage. Bone remodeling defines the primary activities that BMUs need to perform to renew successfully bone structural units. Hence, this review summarizes the current understanding of bone remodeling and future research directions with the aim of providing a clinically relevant biological background with which to identify targets for therapeutic strategies in osteoporosis. 展开更多
关键词 REMODELING replace initially
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Pathophysiology and biology of peritoneal carcinomatosis 被引量:8
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作者 Shigeki Kusamura Dario Baratti +4 位作者 Nadia Zaffaroni Raffaella villa Barbara Laterza Maria Rosaria Balestra Marcello Deraco 《World Journal of Gastrointestinal Oncology》 SCIE CAS 2010年第1期12-18,共7页
Peritoneal carcinomatosis represents a devastating form of cancer progression with a very poor prognosis.Its complex pathogenesis is represented by a dynamic process comprising several steps.To the best of our knowled... Peritoneal carcinomatosis represents a devastating form of cancer progression with a very poor prognosis.Its complex pathogenesis is represented by a dynamic process comprising several steps.To the best of our knowledge pathogenesis can be partly explained by 3 major molecular pathways: (1) dissemination from the primary tumor;(2) primary tumor of peritoneum;and (3) independent origins of the primary tumor and peritoneal implants.These are not mutually exclusive and combinations of different mechanisms could occur inside a single case.There are still several aspects which need explanation by future studies.A comprehensive understanding of molecular events involved in peritoneal carcinomatosis is of paramount importance and should be systematically pursued not only to identify novel strategies for the prevention of the condition,but also to obtain therapeutic advances,through the identification of surrogate markers of prognosis and development of future molecular targeted therapies. 展开更多
关键词 PATHOPHYSIOLOGY PERITONEAL CARCINOMATOSIS PERITONEAL MESOTHELIOMA PSEUDOMYXOMA peritonei Ovarian CANCER Gastric and colorectal CANCER
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Altitude as environmental filtering influencing phylogenetic diversity and species richness of plants in tropical mountains 被引量:3
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作者 GALVÁN-CISNEROS Carlos M. villa Pedro M. +2 位作者 COELHO Alex J.P. CAMPOS Prímula V. MEIRA-NETO João A.A. 《Journal of Mountain Science》 SCIE CSCD 2023年第2期285-298,共14页
Elucidating how multiple factors affect biodiversity and plant community assembly is a central issue in ecology,especially in vulnerable ecosystems such as tropical mountains.These studies are more relevant in global ... Elucidating how multiple factors affect biodiversity and plant community assembly is a central issue in ecology,especially in vulnerable ecosystems such as tropical mountains.These studies are more relevant in global warming scenarios that induce the upward displacement of plant species towards reduced habitats and hostile environments in tropical mountains.This study aimed to analyze how altitude affects taxonomic and phylogenetic diversity in plant communities of tropical mountains.Thus,we tested if(i)increased altitude works as an environmental filtering promoting decreased species richness,decreased phylogenetic diversity,and increased phylogenetic clustering in these tropical mountains;and if(ii)plant communities of high altitude in tropical mountains are also result of recent diversification with plant species recently split shortening phylogenetic distances between closest related species.We tested effects of altitude on species richness and phylogenetic metrics using linear mixed-effects models.Mount Haleakala presented 114 species,Mount Kilimanjaro presented 231 species and Mount Purace presented 280 species.We found an environmental filtering effect with increasing altitude causing phylogenetic clustering,decreased phylogenetic diversity and decreased species richness.The decreasing phylogenetic distances between closest relatives are congruent with neo-endemics,suggesting recent plant diversification in high altitudes of tropical mountains,possibly driven by geographic isolation and environmental heterogeneity.Consequences of global warming should be monitored in tropical mountains focusing on distribution shifts. 展开更多
关键词 Tropical mountains Global warming Environmental filtering Phylogenetic ecology Assembly rules Conservation Mountaintop vegetation
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Case Series of 11 Patients Operated with Axial-LIF Technique in a Single Center in Mexico
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作者 Alfonso Vega Sosa Sergio Ivan Reyna Heredia +10 位作者 Apolinar De la Luz Laguna Ivanka Berenice Moreno villa Marlene de la Peña Gutiérrez Ramiro López Elizalde Cuauhtémoc Gil Ortiz Andres Jaime Aguirre Ivan Alejandro Mendez Guerrero Edwin Rolando Sanchez Vallejo Alejandra Grisel Mendoza Zuñiga Ricardo Cazares Mejía Carlos Erosa Velázquez 《Open Journal of Modern Neurosurgery》 2023年第3期129-136,共8页
Introduction: Since the earliest description of spinal fusion in 1911 and later by Dr. Fred H. Albee, it has become one of the most commonly performed procedures by orthopedist and neurosurgeons. The spinal fusion is ... Introduction: Since the earliest description of spinal fusion in 1911 and later by Dr. Fred H. Albee, it has become one of the most commonly performed procedures by orthopedist and neurosurgeons. The spinal fusion is now used to treat a variety of indications, such as traumatic injuries, deformities, primary and secondary tumors, infections and degenerative conditions of the spine. The risk of iatrogenic injury during traditional anterior, posterior, and transforaminal open fusion surgery is significant. The axial lumbar interbody fusion (Axia-LIF) is a minimal invasive technique which uses the retroperitoneumpresacral anatomical corridor to fuse the lumbar vertebral bodies L4-L5-S1 avoiding manipulation of the annular ligament, paravertebral muscles and facet joints. Methods: In this retrospective series, we report all the cases made in the Centro Medico Naval in México City in two years. A total of eleven patients with degenerative disc disease and spondylolisthesis underwent Axia-LIF one or two level systems with a 36 months clinical and radiographic follow-up. The outcomes included Oswestry Disability Index (ODI) score and leg/back pain severity. Radiographic outcome was evaluated with dynamics and orthogonal x-ray, as well as lumbosacral tomography scan to evaluate fusion status. Results: Nine patients underwent Axia-LIF one level system (L5-S1) and the rest two levels system (L4-S1). Ten patients were fixated with transpedicular percutaneous screws and one with facets joints screws. No intraoperative complications were reported. The mean back pain severity improved 57% in 12 months, and the mean leg pain severity improved 50% in the same time (P < 0.001). Mean ODI scores improved 58%, from 60% ± 16% at baseline to 25% ± 8% at twelve months (P < 0.001). At one year, a patient developed pseudoarthrosis that required posterolateral arthrodesis with transpedicular percutaneous screws. At 36 months monitoring, 100% patients presented a total interbody fusion in the tomography scans. At final follow-up, mean O 展开更多
关键词 Spine Surgery Axial-LIF Procedure Axial-LIF CMN 20 de Noviembre Spinal Fusion Centro Médico Naval
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New insights for the catalytic oxidation of cyclohexane to K-A oil 被引量:5
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作者 Alessandro Vomeri Marta Stucchi +3 位作者 Alberto villa Claudio Evangelisti rea Beck Laura Prati 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第7期45-51,I0002,共8页
Au-based catalysts have been reported to be active in the cyclohexane oxidation to K-A oil, but they showed some limitiations in terms of productivity, selectivity and required reaction conditions. The possibility to ... Au-based catalysts have been reported to be active in the cyclohexane oxidation to K-A oil, but they showed some limitiations in terms of productivity, selectivity and required reaction conditions. The possibility to overcome some of these limits has been explored coupling Au with Cu, which can be suitable for undergoing the electron-switch in the initial step of the cyclohexane oxidation. Hence, a bimetallic 2 wt% Au Cu/Al_(2)O_(3) catalyst was tested in the oxidation of cyclohexane, working at mild conditions of 120 ℃ and 4 bar of O_(2). The combination of the catalyst with a very small amount of benzaldehyde used as cheaper and non-toxic radical initiator allowed to obtain a very high productivity of cyclohexanol and cyclohexanone(45 mmol*m L/mgmet*h) with a selectivity of 94%. Moreover, comparing the catalysed reaction with the non-catalysed one, the role of the catalyst has been disclosed. 展开更多
关键词 K-A oil Cyclohexane oxidation BENZALDEHYDE Radical initiator Heterogeneous catalysis Radical mechanism AuCu bimetallic catalyst
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Application of a biochemical and clinical model to predict individual survival in patients with end-stage liver disease 被引量:6
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作者 Eduardo Vilar Gomez Luis Calzadilla Bertot +5 位作者 Bienvenido Gra Oramas Enrique Arus Soler Raimundo Llanio Navarro Javier Diaz Elias Oscar villa Jiménez Maria del Rosario Abreu Vazquez 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第22期2768-2777,共10页
AIM:To investigate the capability of a biochemical and clinical model,BioCliM,in predicting the survival of cirrhotic patients.METHODS:We prospectively evaluated the survival of 172 cirrhotic patients.The model was co... AIM:To investigate the capability of a biochemical and clinical model,BioCliM,in predicting the survival of cirrhotic patients.METHODS:We prospectively evaluated the survival of 172 cirrhotic patients.The model was constructed using clinical(ascites,encephalopathy and variceal bleeding) and biochemical(serum creatinine and serum total bilirubin) variables that were selected from a Cox proportional hazards model.It was applied to estimate 12-,52-and 104-wk survival.The model's calibration using the Hosmer-Lemeshow statistic was computed at 104 wk in a validation dataset.Finally,the model's validity was tested among an independent set of 85 patients who were stratified into 2 risk groups(low risk≤8 and high risk>8).RESULTS:In the validation cohort,all measures of fi t,discrimination and calibration were improved when the biochemical and clinical model was used.The proposed model had better predictive values(c-statistic:0.90,0.91,0.91) than the Model for End-stage Liver Disease(MELD) and Child-Pugh(CP) scores for 12-,52-and 104-wk mortality,respectively.In addition,the Hosmer-Lemeshow(H-L) statistic revealed that the biochemical and clinical model(H-L,4.69) is better calibrated than MELD(H-L,17.06) and CP(H-L,14.23).There were no significant differences between the observed and expected survival curves in the stratified risk groups(low risk,P=0.61;high risk,P=0.77).CONCLUSION:Our data suggest that the proposed model is able to accurately predict survival in cirrhotic patients. 展开更多
关键词 Liver cirrhosis Prognosis Statistical models Prognostic factors Model for end-stage liver disease score Child-Pugh score SURVIVAL
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Coexpression of CD163 and CD141 identifies human circulating IL-10-producing dendritic cells (DC-10) 被引量:5
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作者 Michela Comi Daniele Avancini +7 位作者 Francesca Santoni de Sio Matteo villa Molly Javier Uyeda Matteo Floris Daniela Tomasoni Alessandro Bulfone Maria Grazia Roncarolo Silvia Gregori 《Cellular & Molecular Immunology》 SCIE CAS CSCD 2020年第1期95-107,共13页
Tolerogenic dendritic cells(DCs)are key players in maintaining immunological homeostasis,dampening immune responses,and promoting tolerance.DC-10,a tolerogenic population of human IL-10-producing DCs characterized by ... Tolerogenic dendritic cells(DCs)are key players in maintaining immunological homeostasis,dampening immune responses,and promoting tolerance.DC-10,a tolerogenic population of human IL-10-producing DCs characterized by the expression of HLA-G and ILT4,play a pivotal role in promoting tolerance via T regulatory type 1(Tr1)cells.Thus far,the absence of markers that uniquely identify DC-10 has limited in vivo studies.By in vitro gene expression profiling of differentiated human DCs,we identified CD141 and CD163 as surface markers for DC-10.The coexpression of CD141 and CD163 in combination with CD14 and CD16 enables the ex vivo isolation of DC-10 from the peripheral blood.CD14+CD16+CD141+CD163+cells isolated from the peripheral blood of healthy subjects(ex vivo DC-10)produced spontaneously and upon activation of IL-10 and limited levels of IL-12.Moreover,in vitro stimulation of allogeneic naive CD4+T cells with ex vivo DC-10 induced the differentiation of alloantigen-specific CD49b+LAG-3+Tr1 cells.Finally,ex vivo DC-10 and in vitro generated DC-10 exhibited a similar transcriptional profile,which are characterized by an anti-inflammatory and pro-tolerogenic signature.These results provide new insights into the phenotype and molecular signature of DC-10 and highlight the tolerogenic properties of circulating DC-10.These findings open the opportunity to track DC-10 in vivo and to define their role in physiological and pathological settings. 展开更多
关键词 Dendritic cells IL-10 T regulatory type 1(Tr1)cells TOLERANCE
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Choice of conodont Idiognathodus simulator (sensu stricto) as the event marker for the base of the global Gzhelian Stage (Upper Pennsylvanian Series, Carboniferous System) 被引量:5
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作者 Philip H. Heckel Aleksandr S. Alekseev +7 位作者 James E. Barrick Darwin R. Boardman Natalya V. Goreva Tatiana N. Isakova Tamara I. Nemyrovska Katsumi Ueno Elisa villa David M. Work 《Episodes》 SCIE 2008年第3期319-325,共7页
We propose that the level at which the conodont species Idiognathodus simulator (Ellison 1941) (sensu stricto) first appears be selected to mark the base of the Gzhelian Stage, because we believe that this is the ... We propose that the level at which the conodont species Idiognathodus simulator (Ellison 1941) (sensu stricto) first appears be selected to mark the base of the Gzhelian Stage, because we believe that this is the optimal level by which this boundary can be correlated. This taxon has a short range and a wide distribution, as shown by correlation of glacial-eustatic cyclothems across the Kasimovian-Gzhelian boundary interval among Midcontinent North America and the Moscow and Donets basins of eastern Europe, based on scale of the cyclothems along with several aspects of biostrati- graphy. Outside of these areas, I. simulator (sensu stricto) is known also from other parts of the U.S., and is reported from the southern Urals and south-central China in its expected position between other widespread taxa. Its first appearance is consistent with the current ammonoid placement of the boundary (first appearance of Shumardites cuyleri), and it is also compatible with certain aspects of the distribution of Eurasian fusulinid faunas (e.g., lectotype ofRauserites rossicus). 展开更多
关键词 牙形石 奇颚牙形石属 模拟技术 岩石学
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Plant diversity and community structure of Brazilian Páramos 被引量:2
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作者 Prímula Viana CAMPOS Pedro Manuel villa +3 位作者 Jaquelina Alves NUNES Carlos E.G.R.SCHAEFER Stefan POREMBSKI Andreza Viana NERI 《Journal of Mountain Science》 SCIE CSCD 2018年第6期1186-1198,共13页
In Eastern South America, high altitude grasslands represent a mountain system that has a high number of endemic species. However, studies on the ecology of plant communities in these environments remain scarce. We ai... In Eastern South America, high altitude grasslands represent a mountain system that has a high number of endemic species. However, studies on the ecology of plant communities in these environments remain scarce. We aimed to evaluate the patterns of biodiversity and structure of plant communities from rocky outcrops in high altitude grasslands of three areas at the Caparaó National Park, southeastern Brazil, by sampling 300 randomly distributed plots. Then, we compared the floristic composition, relative abundance, and biological and vegetation spectra among areas. We classified species as endemic and non-endemic and verified the occurrence of endangered species. Species richness was evaluated by rarefaction analysis on the sampling units. The importance value and species abundance distribution(SAD) models were assessed. We also performed an indicator species analysis. We sampled 58 species belonging to 49 genera and 32 families. The number of species decreased with increasing altitude, with significant differences being observed among areas regarding richness, abundance, and cover. Of the total number of species, 10 are endemic to the Caparaó National Park and 17 are listed on the Brazilian Red List of endangered species. The dominant families on all peaks were Asteraceae and Poaceae. The SAD models showed lognormal and geometric distributions, corroborating the fact that 10 species that were common to all three areas were also the most dominant ones in the communities and showed the highest importance values, which ranged between 35% and 60%. Indicator species analysis revealed that 28 species(48.27%) were indicators. Of these, 42.85% had maximum specificity, meaning that they occurred only in one area. Thus, the number of species per life form ratio was similar among areas, yet vegetation spectra differed, especially for hemicryptophytes. The altimetric difference among the areas showed to be a very important driver in the community assembly, influencing the evaluated variables, however, other drivers as soil 展开更多
关键词 Rock outcrops High altitude grasslands Species abundance distribution Species richness
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Role of pulmonary perfusion magnetic resonance imaging for the diagnosis of pulmonary hypertension:A review
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作者 Miriam Lacharie Adriana villa +3 位作者 Xenios Milidonis Hadeer Hasaneen Amedeo Chiribiri Giulia Benedetti 《World Journal of Radiology》 2023年第9期256-273,共18页
Among five types of pulmonary hypertension,chronic thromboembolic pulmonary hypertension(CTEPH)is the only curable form,but prompt and accurate diagnosis can be challenging.Computed tomography and nuclear medicine-bas... Among five types of pulmonary hypertension,chronic thromboembolic pulmonary hypertension(CTEPH)is the only curable form,but prompt and accurate diagnosis can be challenging.Computed tomography and nuclear medicine-based techniques are standard imaging modalities to non-invasively diagnose CTEPH,however these are limited by radiation exposure,subjective qualitative bias,and lack of cardiac functional assessment.This review aims to assess the methodology,diagnostic accuracy of pulmonary perfusion imaging in the current literature and discuss its advantages,limitations and future research scope. 展开更多
关键词 Pulmonary perfusion MRI Pulmonary hypertension Dynamic contrast enhanced magnetic resonance imaging Chronic thromboembolic pulmonary hypertension Computed tomography pulmonary angiography Chronic thromboembolic disease
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Patterns of species richness and beta diversity of vascular plants along elevation gradient in Brazilian páramo
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作者 CORDEIRO Anais de Almeida Campos KLANDERUD Kari +1 位作者 villa Pedro Manuel NERI Andreza Viana 《Journal of Mountain Science》 SCIE CSCD 2023年第7期1911-1920,共10页
Understanding the relationships between plant diversity and the environment is an important step towards conservation of species and ecosystems.In this study,we hypothesize that community species richness decreases an... Understanding the relationships between plant diversity and the environment is an important step towards conservation of species and ecosystems.In this study,we hypothesize that community species richness decreases and species composition change along the elevation gradient,with a greater contribution of species turnover than nestedness to beta diversity.We surveyed plant species in 300 plots(1 m×1 m)in four elevational bands(2100 m,2300m,2500 m,and 2700 m)in the CaparaóNational Park,Southeastern Brazil.The samples presented a great number of species(97 spp.,59 genera,27families),however,74%of the species were considered rare with their relative abundance being<1%.Among the four bands along the gradient,we detected two distinct communities with few species in common.The transition between the two communities occurred at 2500 m,and this elevation band also had the highest species richness in total.A non-metric multidimensional scaling(NMDS)showed floristic differences between the bands even though they had similar richness.In 89%of the plot pairs,using pairwise comparison of species composition,only half of the species that occurred in one did occur in the other plot.The dissimilarity among the plots and elevational band reflects a significant contribution of spatial species turnover to the species richness and beta diversity on the Caparaómountain.Beta diversity increased with spatial scale(from plot to elevational-band).The dissimilarity(βSOR=0.907)in the area was due almost exclusively to spatial species turnover(βSIM=0.879),with very low contribution of species nestedness(βSNE=0.028).Our research showed that species richness does not decrease with elevation in the study area,but the floristic composition changes.The clear distinction of species along the gradient show that spatial species turnover is the major diversitygenerating process in the studied area. 展开更多
关键词 High altitude grassland Species turnover Partitioning diversity Campo de altitude Tropical mountains
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Search for the doubly heavy baryon Ξ_(bc)^(+)→ decaying to J/ψΞ_(c)^(+)
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作者 R.Aaij A.S.W.Abdelmotteleb +132 位作者 C.Abellan Beteta F.Abudinén T.Ackernley B.Adeva M.Adinolfi H.Afsharnia C.Agapopoulou C.A.Aidala S.Aiola Z.Ajaltouni S.Akar K.Akiba J.Albrecht F.Alessio M.Alexander A.Alfonso Albero Z.Aliouche P.Alvarez Cartelle S.Amato J.L.Amey Y.Amhis L.An L.Anderlini M.Andersson A.Andreianov M.Andreotti D.Andreou D.Ao F.Archilli A.Artamonov M.Artuso E.Aslanides M.Atzeni B.Audurier S.Bachmann M.Bachmayer J.J.Back A.Bailly-reyre P.Baladron Rodriguez V.Balagura W.Baldini J.Baptista de Souza Leite M.Barbetti R.J.Barlow S.Barsuk W.Barter M.Bartolini F.Baryshnikov J.M.Basels G.Bassi B.Batsukh A.Battig A.Bay A.Beck M.Becker F.Bedeschi I.B.Bediaga A.Beiter V.Belavin S.Belin V.Bellee K.Belous I.Belov I.Belyaev G.Bencivenni E.Ben-Haim A.Berezhnoy R.Bernet D.Berninghoff H.C.Bernstein C.Bertella A.Bertolin C.Betancourt F.Betti Ia.Bezshyiko S.Bhasin J.Bhom L.Bian M.S.Bieker N.V.Biesuz S.Bifani P.Billoir A.Biolchini M.Birch F.C.R.Bishop A.Bitadze A.Bizzeti M.P.Blago T.Blake F.Blanc S.Blusk D.Bobulska J.A.Boelhauve O.Boente Garcia T.Boettcher A.Boldyrev N.Bondar S.Borghi M.Borsato J.T.Borsuk S.A.Bouchiba T.J.V.Bowcock A.Boyer C.Bozzi M.J.Bradley S.Braun A.Brea Rodriguez J.Brodzicka A.Brossa Gonzalo D.Brundu A.Buonaura L.Buonincontri A.T.Burke C.Burr A.Bursche A.Butkevich J.S.Butter J.Buytaert W.Byczynski S.Cadeddu H.Cai R.Calabrese L.Calefice S.Cali R.Calladine M.Calvi M.Calvo Gomez P.Camargo Magalhaes P.Campana D.H.Campora Perez A.F.Campoverde Quezada S.Capelli L.Caprio 《Chinese Physics C》 SCIE CAS CSCD 2023年第9期1-13,共13页
A first search for the Ξ_(bc)^(+)J/ψΞ_(c)^(+) decay is performed by the LHCb experiment with a data sample of proton-proton collisions, corresponding to an integrated luminosity of 9 fb−1 recorded at centre-of-mass... A first search for the Ξ_(bc)^(+)J/ψΞ_(c)^(+) decay is performed by the LHCb experiment with a data sample of proton-proton collisions, corresponding to an integrated luminosity of 9 fb−1 recorded at centre-of-mass energies of 7, 8, and 13 TeV. Two peaking structures are seen with a local (global) significance of 4.3(2.8) and 4.1(2.4) standard deviations at masses of 6571 and 6694 MeV/c2, respectively. Upper limits are set on the Ξ+bc baryon production cross-section times the branching fraction relative to that of the B+c→J/ψD+s decay at centre-of-mass energies of 8 and 13 TeV, in the Ξ+bc and in the B+c rapidity and transverse-momentum ranges from 2.0 to 4.5 and 0 to 20GeV/c, respectively. Upper limits are presented as a function of the Ξ+bc mass and lifetime. 展开更多
关键词 QCD B physics charm physics spectroscopy
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Search for the rare decays W^(+)→D_(s)^(+)γ and Z→D^(0)γ at LHCb
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作者 R.Aaij A.S.W.Abdelmotteleb +134 位作者 C.Abellan Beteta F.Abudinén T.Ackernley B.Adeva M.Adinolfi P.Adlarson H.Afsharnia C.Agapopoulou C.A.Aidala Z.Ajaltouni S.Akar K.Akiba J.Albrecht F.Alessio M.Alexander A.Alfonso Albero Z.Aliouche P.Alvarez Cartelle R.Amalric S.Amato J.L.Amey Y.Amhis L.An L.Anderlini M.Andersson A.Andreianov M.Andreotti D.Andreou D.Ao F.Archilli A.Artamonov M.Artuso E.Aslanides M.Atzeni B.Audurier S.Bachmann M.Bachmayer J.J.Back A.Bailly-reyre P.Baladron Rodriguez V.Balagura W.Baldini J.Baptista de Souza Leite M.Barbetti R.J.Barlow S.Barsuk W.Barter M.Bartolini F.Baryshnikov J.M.Basels G.Bassi B.Batsukh A.Battig A.Bay A.Beck M.Becker F.Bedeschi I.B.Bediaga A.Beiter V.Belavin S.Belin V.Bellee K.Belous I.Belov I.Belyaev G.Benane G.Bencivenni E.Ben-Haim A.Berezhnoy R.Bernet S.Bernet Andres D.Berninghoff H.C.Bernstein C.Bertella A.Bertolin C.Betancourt F.Betti Ia.Bezshyiko S.Bhasin J.Bhom L.Bian M.S.Bieker N.V.Biesuz S.Bifani P.Billoir A.Biolchini M.Birch F.C.R.Bishop A.Bitadze A.Bizzeti M.P.Blago T.Blake F.Blanc J.E.Blank S.Blusk D.Bobulska J.A.Boelhauve O.Boente Garcia T.Boettcher A.Boldyrev C.S.Bolognani R.Bolzonella N.Bondar F.Borgato S.Borghi M.Borsato J.T.Borsuk S.A.Bouchiba T.J.V.Bowcock A.Boyer C.Bozzi M.J.Bradley S.Braun A.Brea Rodriguez J.Brodzicka A.Brossa Gonzalo J.Brown D.Brundu A.Buonaura L.Buonincontri A.T.Burke C.Burr A.Bursche A.Butkevich J.S.Butter J.Buytaert W.Byczynski S.Cadeddu H.Cai R.Calabrese L.Calefice S.Cali R.Calladine M.Calvi M.Calv 《Chinese Physics C》 SCIE CAS CSCD 2023年第9期14-26,共13页
A search for the rare decays W^(+)→D_(s)^(+)γ and Z→D0γis performed using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13TeV,corresponding to an integrated luminosity... A search for the rare decays W^(+)→D_(s)^(+)γ and Z→D0γis performed using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13TeV,corresponding to an integrated luminosity of 2.0fb−1.No significant signal is observed for either decay mode and upper limits on their branching fractions are set using W^(+)→D_(s)^(+)γ and Z→μ+μ−decays as normalization channels.The upper limits are 6.5×10^(−4) and 2.1×10^(−3) at 95% confidence level for the W^(+)→D_(s)^(+)γ and Z→D^(0)γ decay modes,respectively.This is the first reported search for the Z→D^(0)γ decay,while the upper limit on the W+→D+sγbranching fraction improves upon the previous best limit. 展开更多
关键词 W/Z boson rare decay upper limit of branching fraction
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