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1.
Cell ; 175(3): 709-722.e15, 2018 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-30245010

RESUMO

Accurately predicting an outcome requires that animals learn supporting and conflicting evidence from sequential experience. In mammals and invertebrates, learned fear responses can be suppressed by experiencing predictive cues without punishment, a process called memory extinction. Here, we show that extinction of aversive memories in Drosophila requires specific dopaminergic neurons, which indicate that omission of punishment is remembered as a positive experience. Functional imaging revealed co-existence of intracellular calcium traces in different places in the mushroom body output neuron network for both the original aversive memory and a new appetitive extinction memory. Light and ultrastructural anatomy are consistent with parallel competing memories being combined within mushroom body output neurons that direct avoidance. Indeed, extinction-evoked plasticity in a pair of these neurons neutralizes the potentiated odor response imposed in the network by aversive learning. Therefore, flies track the accuracy of learned expectations by accumulating and integrating memories of conflicting events.


Assuntos
Extinção Psicológica , Memória , Animais , Comportamento Apetitivo , Cálcio/metabolismo , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/fisiologia , Drosophila melanogaster , Feminino , Corpos Pedunculados/citologia , Corpos Pedunculados/fisiologia , Plasticidade Neuronal
2.
Nature ; 600(7889): 429-433, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34912091

RESUMO

The control of physical systems and their dynamics on the level of individual quanta underpins both fundamental science and quantum technologies. Trapped atomic and molecular systems, neutral1 and charged2, are at the forefront of quantum science. Their extraordinary level of control is evidenced by numerous applications in quantum information processing3,4 and quantum metrology5,6. Studies of the long-range interactions between these systems when combined in a hybrid atom-ion trap7,8 have led to landmark results9-19. However, reaching the ultracold regime-where quantum mechanics dominates the interaction, for example, giving access to controllable scattering resonances20,21-has so far been elusive. Here we demonstrate Feshbach resonances between ions and atoms, using magnetically tunable interactions between 138Ba+ ions and 6Li atoms. We tune the experimental parameters to probe different interaction processes-first, enhancing three-body reactions22,23 and the related losses to identify the resonances and then making two-body interactions dominant to investigate the ion's sympathetic cooling19 in the ultracold atomic bath. Our results provide deeper insights into atom-ion interactions, giving access to complex many-body systems24-27 and applications in experimental quantum simulation28-30.

3.
Phys Rev Lett ; 132(13): 133003, 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38613289

RESUMO

We report the optical trapping of multiple ions localized at individual lattice sites of a one-dimensional optical lattice. We observe a fivefold increased range of axial dc-electric field strength for which ions can be optically trapped with high probability and an increase of the axial eigenfrequency by 2 orders of magnitude compared to an optical dipole trap without interference but of similar intensity. Our findings motivate an alternative pathway to extend arrays of trapped ions in size and dimension, enabling quantum simulations with particles interacting at long range.

4.
Phys Chem Chem Phys ; 26(5): 4111-4117, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38226631

RESUMO

We present the low temperature gas-phase vibrational spectrum of ionised 1-cyanonaphthalene (1-CNN+) in the mid-infrared region. Experimentally, 1-CNN+ ions are cooled below 10 K in a cryogenic ion trapping apparatus, tagged with He atoms and probed with tuneable radiation. Quantum-chemical calculations are carried out at a density functional theory level. The spectrum is dominated by the CN-stretch at 4.516 µm, with weaker CH modes near 3.2 µm.

5.
Int J Mass Spectrom ; 4972024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38352886

RESUMO

Through optimization of terminal frequencies and effective sampling rates, we have developed nonlinear sawtooth-shaped frequency sweeps for efficient Fourier transform ion mobility mass spectrometry (FT-IM-MS) experiments. This is in contrast to conventional FT-IM-MS experiments where ion gates are modulated according to a linear frequency sweep. Linear frequency sweeps are effective but can be hindered by the amount of useful signal obtained using a single sweep over a large frequency range imposed by ion gating inefficiencies, particularly small ion packets, and gate depletion. These negative factors are direct consequences of the inherently low gate pulse widths of high-frequency ion gating events, placing an upper bound on FT-IM-MS performance. Here, we report alternative ion modulation strategies. Sawtooth frequency sweeps may be constructed for the purpose of either extending high-SNR transients or conducting efficient signal-averaging experiments for low-SNR transients. The data obtained using this approach show high-SNR signals for a set of low-mass tetraalkylammonium salts (<1000 m/z) where resolving powers in excess of 500 are achieved. Data for low-SNR obtained for multimeric protein complexes streptavidin (53 kDa) and GroEL (800 kDa) also reveal large increases in the signal-to-noise ratio for reconstructed arrival time distributions.

6.
Memory ; : 1-11, 2024 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-38972048

RESUMO

ABSTRACTDeficits in episodic memory have been reported in various psychiatric conditions, including Major Depressive Disorder (MDD). Many widely used episodic memory tests do not have the ability to distinguish between impaired memory of separate components of a real-life event (e.g., what happened, where it happened and when), and impaired binding of such real-life features. To address this issue, a naturalistic, real-world What-Where-When memory task was employed to assess the nature of episodic memory impairments in MDD. A validation study established that the task is sensitive to age-related episodic memory changes, and that intentional encoding does not invalidate the task. The main study then compared the performance of patients with depression and control participants on the intentionally encoded WWW task. Patients with MDD presented an overall episodic memory impairment arising from deficits in object memory and the ability to bind objects to temporal context. Taken together, our study confirms the episodic memory impairment in MDD, by providing evidence of deficient object memory and reduced ability to bind temporal context to objects in patients. Our naturalistic WWW task presents a promising approach for thorough identification of the nature of episodic memory impairments, under a real-world environment, in various conditions, including MDD.

7.
Br J Cancer ; 128(9): 1765-1776, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36810910

RESUMO

BACKGROUND: Ovarian cancers are hallmarked by chromosomal instability. New therapies deliver improved patient outcomes in relevant phenotypes, however therapy resistance and poor long-term survival signal requirements for better patient preselection. An impaired DNA damage response (DDR) is a major chemosensitivity determinant. Comprising five pathways, DDR redundancy is complex and rarely studied alongside chemoresistance influence from mitochondrial dysfunction. We developed functional assays to monitor DDR and mitochondrial states and trialled this suite on patient explants. METHODS: We profiled DDR and mitochondrial signatures in cultures from 16 primary-setting ovarian cancer patients receiving platinum chemotherapy. Explant signature relationships to patient progression-free (PFS) and overall survival (OS) were assessed by multiple statistical and machine-learning methods. RESULTS: DR dysregulation was wide-ranging. Defective HR (HRD) and NHEJ were near-mutually exclusive. HRD patients (44%) had increased SSB abrogation. HR competence was associated with perturbed mitochondria (78% vs 57% HRD) while every relapse patient harboured dysfunctional mitochondria. DDR signatures classified explant platinum cytotoxicity and mitochondrial dysregulation. Importantly, explant signatures classified patient PFS and OS. CONCLUSIONS: Whilst individual pathway scores are mechanistically insufficient to describe resistance, holistic DDR and mitochondrial states accurately predict patient survival. Our assay suite demonstrates promise for translational chemosensitivity prediction.


Assuntos
Neoplasias Ovarianas , Platina , Humanos , Feminino , Platina/uso terapêutico , Dano ao DNA , Recidiva Local de Neoplasia , Carcinoma Epitelial do Ovário , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Aprendizado de Máquina
8.
Anal Chem ; 95(5): 3062-3068, 2023 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-36701646

RESUMO

Digital mass filters are advantageous for the analysis of large molecules due to the ability to perform ion isolation of high-m/z ions without the generation of very high radio frequency (RF) and DC voltages. Experimentally determined Mathieu stability diagrams of stability zone 1,1 for capacitively coupled digital waveforms show a voltage offset between the quadrupole rod pairs is introduced by the capacitors which is dependent on the voltage magnitude of the waveform and the duty cycle. This changes the ion's a value from a = 0 to a < 0. These effects are illustrated for isolation for single-charge states for various protein complexes up to 800 kDa (GroEL) for stability zone 1,1. Isolation resolving power (m/Δm) of approximately 280 was achieved for an ion of m/z 12,315 (z = 65+ for 800.5 kDa GroEL D398A), which corresponds to an m/z window of 44.


Assuntos
Proteínas , Ondas de Rádio , Íons , Proteínas/química
9.
Artigo em Inglês | MEDLINE | ID: mdl-37335195

RESUMO

OBJECTIVE: Blood-based biomarkers have received considerable attention for their diagnostic and prognostic value in the acute and postacute period following traumatic brain injury (TBI). The purpose of this study was to examine whether blood-based biomarker concentrations within the first 12 months of TBI can predict neurobehavioral outcome in the chronic phase of the recovery trajectory. SETTING: Inpatient and outpatient wards from 3 military medical treatment facilities. PARTICIPANTS: A total of 161 service members and veterans classified into 3 groups: (a) uncomplicated mild TBI (MTBI; n = 37), (b) complicated mild, moderate, severe, penetrating TBI combined (STBI; n = 46), and (c) controls (CTRL; n = 78). DESIGN: Prospective longitudinal. MAIN MEASURES: Participants completed 6 scales from the Traumatic Brain Injury Quality of Life (ie, Anger, Anxiety, Depression, Fatigue, Headaches, and Cognitive Concerns) within 12 months (baseline) and at 2 or more years (follow-up) post-injury. Serum concentrations of tau, neurofilament light, glial fibrillary acidic protein, and UCHL-1 at baseline were measured using SIMOA. RESULTS: Baseline tau was associated with worse anger, anxiety, and depression in the STBI group at follow-up (R2 = 0.101-0.127), and worse anxiety in the MTBI group (R2 = 0.210). Baseline ubiquitin carboxyl-terminal hydrolase L1 (UCHL-1) was associated with worse anxiety and depression at follow-up in both the MTBI and STBI groups (R2Δ = 0.143-0.207), and worse cognitive concerns in the MTBI group (R2Δ = 0.223). CONCLUSIONS: A blood-based panel including these biomarkers could be a useful tool for identifying individuals at risk of poor outcome following TBI.

10.
J Environ Manage ; 342: 117991, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37224654

RESUMO

Climate change has intensified water risk events, threatening water security for societies and ecosystems. Although current water risk models focus on geophysical and business-related effects, they do not quantify the monetary dimensions of water-related challenges and opportunities. This study aims to address this gap by exploring the objectives and directions for modeling water risk in finance. We identify requirements for adequately modeling financial water risk, assess existing water risk approaches in finance, outline their benefits and shortcomings, and develop directions for future modeling. Recognizing the interplay between climate and water as well as the systemic dimension of water risk, we emphasize the need for forward-looking, diversification-based, and mitigation-adjusted modeling approaches.


Assuntos
Ecossistema , Água , Abastecimento de Água , Mudança Climática
11.
J Environ Manage ; 326(Pt A): 116552, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36372039

RESUMO

Sustainable practices in the building industry are strongly influenced by published green and sustainable building and real-estate standards (GSBRES). Therefore, it is crucial to assess how these standards contribute to achieving the United Nations' Sustainable Development Goals (SDGs). This paper evaluates the extent to which GSBRESs align with the 2030 Agenda for Sustainable Development, lending a particular focus to the call for transformative change implicit in the SDGs. To this end, we develop a methodology that combines qualitative and quantitative analysis to assess the overlap between the content of three GSBRESs (LEED for design, BOMA BEST for operation, and GRESB for investment) and the SDGs. Despite the overlaps between the attributes of the GSBRESs and the general topics of the SDGs, we find that less than 20% of GSBRES attributes address the specific targets of the 2030 Agenda. Most importantly, the qualitative analysis shows that less than 10% of the standards' scores is attributed to transformative change. We conclude that claims that the GSBRESs are effective in advancing the SDGs are overstated and, without further empirical evidence, caution that they increase the risk of sustainable development greenwashing. We recommend that the standards be repositioned to adopt transformation-focused indicators related to a project's long-term impacts.


Assuntos
Desenvolvimento Sustentável , Nações Unidas , Objetivos
12.
J Infect Dis ; 225(8): 1424-1434, 2022 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-33175129

RESUMO

BACKGROUND: Resistance to major public health insecticides in Côte d'Ivoire has intensified and now threatens the long-term effectiveness of malaria vector control interventions. METHODS: This study evaluated the bioefficacy of conventional and next-generation long-lasting insecticidal nets (LLINs), determined resistance profiles, and characterized molecular and metabolic mechanisms in wild Anopheles coluzzii from Southeast Côte d'Ivoire in 2019. RESULTS: Phenotypic resistance was intense: >25% of mosquitoes survived exposure to 10 times the doses of pyrethroids required to kill susceptible populations. Similarly, the 24-hour mortality rate with deltamethrin-only LLINs was very low and not significantly different from that with an untreated net. Sublethal pyrethroid exposure did not induce significant delayed vector mortality effects 72 hours later. In contrast, LLINs containing the synergist piperonyl butoxide, or new insecticides clothianidin and chlorfenapyr, were highly toxic to A. coluzzii. Pyrethroid-susceptible A. coluzzii were significantly more likely to be infected with malaria, compared with those that survived insecticidal exposure. Pyrethroid resistance was associated with significant overexpression of CYP6P4, CYP6P3, and CYP6Z1. CONCLUSIONS: Study findings raise concerns regarding the operational failure of standard LLINs and support the urgent deployment of vector control interventions incorporating piperonyl butoxide, chlorfenapyr, or clothianidin in areas of high resistance intensity in Côte d'Ivoire.


Assuntos
Anopheles , Mosquiteiros Tratados com Inseticida , Inseticidas , Malária , Piretrinas , Animais , Côte d'Ivoire , Resistência a Inseticidas , Inseticidas/farmacologia , Malária/prevenção & controle , Controle de Mosquitos , Mosquitos Vetores , Butóxido de Piperonila/farmacologia , Piretrinas/farmacologia
13.
Eur J Orthop Surg Traumatol ; 33(8): 3287-3297, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37286819

RESUMO

PURPOSE: Poor outcomes and high complication and reoperation rates have been reported with tension-band wiring (TBW) in the management of patellar fractures and particularly the comminuted ones. The purpose of this study was to investigate the functional outcomes and complication rates of patellar fractures managed with open reduction and internal fixation (ORIF) with a plate. METHODS: MEDLINE, EMCare, CINAHL, AMED and HMIC were searched, and the PRISMA guidelines were followed. Two independent reviewers extracted the data from the included studies and assessed them for the risk of bias. RESULTS: Plating of patellar fractures is associated with satisfactory range of movement (ROM) and postoperative function and low pain levels. We found a 10.44% complication rate and a low reoperation rate. Reoperations were mainly performed for metalwork removal. CONCLUSION: ORIF with plating of patellar fractures is a safe alternative in the management of patellar fractures and may be associated with a lower complication and reoperation rate compared to TBW. Future randomized prospective studies are needed to validated the results of the present systematic review.


Assuntos
Fraturas Ósseas , Fraturas Cominutivas , Traumatismos do Joelho , Humanos , Fraturas Ósseas/cirurgia , Fixação Interna de Fraturas/efeitos adversos , Fixação Interna de Fraturas/métodos , Traumatismos do Joelho/cirurgia , Fraturas Cominutivas/cirurgia , Reoperação , Estudos Retrospectivos , Patela/cirurgia
14.
J Am Chem Soc ; 144(6): 2667-2678, 2022 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-35107280

RESUMO

Chaperonins are nanomachines that harness ATP hydrolysis to power and catalyze protein folding, a chemical action that is directly linked to the maintenance of cell function through protein folding/refolding and assembly. GroEL and the GroEL-GroES complex are archetypal examples of such protein folding machines. Here, variable-temperature electrospray ionization (vT-ESI) native mass spectrometry is used to delineate the effects of solution temperature and ATP concentrations on the stabilities of GroEL and GroEL-GroES complexes. The results show clear evidence for destabilization of both GroEL14 and GroES7 at temperatures of 50 and 45 °C, respectively, substantially below the previously reported melting temperature (Tm ∼ 70 °C). This destabilization is accompanied by temperature-dependent reaction products that have previously unreported stoichiometries, viz. GroEL14-GroESy-ATPn, where y = 1, 2, 8 and n = 0, 1, 2, 8, that are also dependent on Mg2+ and ATP concentrations. Variable-temperature native mass spectrometry reveals new insights about the stability of GroEL in response to temperature effects: (i) temperature-dependent ATP binding to GroEL; (ii) effects of temperature as well as Mg2+ and ATP concentrations on the stoichiometry of the GroEL-GroES complex, with Mg2+ showing greater effects compared to ATP; and (iii) a change in the temperature-dependent stoichiometries of the GroEL-GroES complex (GroEL14-GroES7 vs GroEL14-GroES8) between 24 and 40 °C. The similarities between results obtained by using native MS and cryo-EM [Clare et al. An expanded protein folding cage in the GroEL-gp31 complex. J. Mol. Biol. 2006, 358, 905-911; Ranson et al. Allosteric signaling of ATP hydrolysis in GroEL-GroES complexes.Nat. Struct. Mol. Biol. 2006, 13, 147-152] underscore the utility of native MS for investigations of molecular machines as well as identification of key intermediates involved in the chaperonin-assisted protein folding cycle.


Assuntos
Trifosfato de Adenosina/metabolismo , Chaperonina 10/metabolismo , Chaperonina 60/metabolismo , Magnésio/metabolismo , Chaperonina 10/química , Chaperonina 60/química , Escherichia coli/química , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Ligantes , Espectrometria de Massas , Ligação Proteica , Conformação Proteica , Estabilidade Proteica , Desdobramento de Proteína , Temperatura
15.
J Am Chem Soc ; 144(16): 7048-7053, 2022 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-35421309

RESUMO

TRAAK and TREK2 are two-pore domain K+ (K2P) channels and are modulated by diverse factors including temperature, membrane stretching, and lipids, such as phosphatidic acid. In addition, copper and zinc, both of which are essential for life, are known to regulate TREK2 and a number of other ion channels. However, the role of ions in the association of lipids with integral membrane proteins is poorly understood. Here, we discover cupric ions selectively modulate the binding of phosphatidylserine (PS) to TRAAK but not TREK2. Other divalent cations (Ca2+, Mg2+, and Zn2+) bind both channels but have no impact on binding PS and other lipids. Additionally, TRAAK binds more avidly to Cu2+ and Zn2+ than TREK2. In the presence of Cu2+, TRAAK binds similarly to PS with different acyl chains, indicating a crucial role of the serine headgroup in coordinating Cu2+. High-resolution native mass spectrometry (MS) enables the determination of equilibrium binding constants for distinct Cu2+-bound stoichiometries and uncovered the highest coupling factor corresponds to a 1:1 PS-to-Cu2+ ratio. Interestingly, the next three highest coupling factors had a ∼1.5:1 PS-to-Cu2+ ratio. Our findings bring forth the role of cupric ions as an essential cofactor in selective TRAAK-PS interactions.


Assuntos
Canais de Potássio de Domínios Poros em Tandem , Cátions Bivalentes/metabolismo , Fosfatidilserinas , Canais de Potássio de Domínios Poros em Tandem/química , Canais de Potássio de Domínios Poros em Tandem/metabolismo
16.
Anal Chem ; 94(30): 10824-10831, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35862200

RESUMO

Charge reduction reactions are important for native mass spectrometry (nMS) because lower charge states help retain native-like conformations and preserve noncovalent interactions of protein complexes. While mechanisms of charge reduction reactions are not well understood, they are generally achieved through the addition of small molecules, such as polyamines, to traditional nMS buffers. Here, we present new evidence that surface-active, charge reducing reagents carry away excess charge from the droplet after being emitted due to Coulombic repulsion, thereby reducing the overall charge of the droplet. Furthermore, these processes are directly linked to two mechanisms for electrospray ionization, specifically the charge residue and ion evaporation models (CRM and IEM). Selected protein complexes were analyzed in solutions containing ammonium acetate and selected trialkylamines or diaminoalkanes of increasing alkyl chain lengths. Results show that amines with higher surface activity have increased propensities for promoting charge reduction of the protein ions. The electrospray ionization (ESI) emitter potential was also found to be a major contributing parameter to the prevalence of charge reduction; higher emitter potentials consistently coincided with lower average charge states among all protein complexes analyzed. These results offer experimental evidence for the mechanism of charge reduction in ESI and also provide insight into the final stages of the ESI and their impact on biological ions.


Assuntos
Aminas , Espectrometria de Massas por Ionização por Electrospray , Íons/química , Proteínas/química , Espectrometria de Massas por Ionização por Electrospray/métodos
17.
Int J Obes (Lond) ; 46(3): 605-612, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34857870

RESUMO

BACKGROUND: The incidence of endometrial cancer is rising in parallel with the obesity epidemic. Obesity increases endometrial cancer risk and weight loss is protective, but the underlying mechanisms are incompletely understood. We hypothesise that the immune microenvironment may influence susceptibility to malignant transformation in the endometrium. The aim of this study was to measure the impact of obesity and weight loss on the immunological landscape of the endometrium. METHODS: We conducted a prospective cohort study of women with class III obesity (body mass index, BMI ≥ 40 kg/m2) undergoing bariatric surgery or medically-supervised low-calorie diet. We collected blood and endometrial samples at baseline, and two and 12 months after weight loss intervention. Serum was analysed for inflammatory markers CRP, IL-6 and TNF-α. Multiplex immunofluorescence was used to simultaneously identify cells positive for immune markers CD68, CD56, CD3, CD8, FOXP3 and PD-1 in formalin-fixed paraffin-embedded endometrial tissue sections. Kruskal-Wallis tests were used to determine whether changes in inflammatory and immune biomarkers were associated with weight loss. RESULTS: Forty-three women with matched serum and tissue samples at all three time points were included in the analysis. Their median age and BMI were 44 years and 52 kg/m2, respectively. Weight loss at 12 months was greater in women who received bariatric surgery (n = 37, median 63.3 kg) than low-calorie diet (n = 6, median 12.8 kg). There were significant reductions in serum CRP (p = 3.62 × 10-6, r = 0.570) and IL-6 (p = 0.0003, r = 0.459), but not TNF-α levels, with weight loss. Tissue immune cell densities were unchanged except for CD8+ cells, which increased significantly with weight loss (p = 0.0097, r = -0.323). Tissue CD3+ cell density correlated negatively with systemic IL-6 levels (p = 0.0376; r = -0.318). CONCLUSION: Weight loss is associated with reduced systemic inflammation and a recruitment of protective immune cell types to the endometrium, supporting the concept that immune surveillance may play a role in endometrial cancer prevention.


Assuntos
Cirurgia Bariátrica , Neoplasias do Endométrio , Endométrio , Biomarcadores , Neoplasias do Endométrio/epidemiologia , Endométrio/imunologia , Feminino , Humanos , Vigilância Imunológica , Interleucina-6/metabolismo , Obesidade/complicações , Obesidade/cirurgia , Estudos Prospectivos , Microambiente Tumoral , Redução de Peso
18.
Mass Spectrom Rev ; 40(3): 280-305, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-32608033

RESUMO

Studies of large proteins, protein complexes, and membrane protein complexes pose new challenges, most notably the need for increased ion mobility (IM) and mass spectrometry (MS) resolution. This review covers evolutionary developments in IM-MS in the authors' and key collaborators' laboratories with specific focus on developments that enhance the utility of IM-MS for structural analysis. IM-MS measurements are performed on gas phase ions, thus "structural IM-MS" appears paradoxical-do gas phase ions retain their solution phase structure? There is growing evidence to support the notion that solution phase structure(s) can be retained by the gas phase ions. It should not go unnoticed that we use "structures" in this statement because an important feature of IM-MS is the ability to deal with conformationally heterogeneous systems, thus providing a direct measure of conformational entropy. The extension of this work to large proteins and protein complexes has motivated our development of Fourier-transform IM-MS instruments, a strategy first described by Hill and coworkers in 1985 (Anal Chem, 1985, 57, pp. 402-406) that has proved to be a game-changer in our quest to merge drift tube (DT) and ion mobility and the high mass resolution orbitrap MS instruments. DT-IMS is the only method that allows first-principles determinations of rotationally averaged collision cross sections (CSS), which is essential for studies of biomolecules where the conformational diversities of the molecule precludes the use of CCS calibration approaches. The Fourier transform-IM-orbitrap instrument described here also incorporates the full suite of native MS/IM-MS capabilities that are currently employed in the most advanced native MS/IM-MS instruments. © 2020 John Wiley & Sons Ltd. Mass Spec Rev.


Assuntos
Espectrometria de Massas/métodos , Proteínas/química , Análise de Fourier , Espectrometria de Massas/instrumentação , Peptídeos/análise , Peptídeos/química , Conformação Proteica , Dobramento de Proteína , Estabilidade Proteica , Proteínas/análise , Solventes/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Ubiquitina , Água/química
19.
J Pediatr Gastroenterol Nutr ; 75(6): 737-742, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36122373

RESUMO

OBJECTIVES: Celiac disease (CeD) autoimmunity and coexisting inflammatory bowel disease (IBD) present a diagnostic dilemma. Our aims were to describe the phenotype of children with IBD and CeD seropositivity and evaluate provider confidence for diagnosing CeD in this population. METHODS: We performed a single-center retrospective cohort study of subjects ≤18 years old with IBD and CeD seropositivity between 2006 and 2020. Subjects were considered to have IBD-CeD if they met CeD diagnosis by serology and histology per North American Society For Pediatric Gastroenterology, Hepatology and Nutrition guidelines and if providers suspected CeD as evaluated by a survey. The IBD-only cohort included seropositive participants that did not meet criteria for CeD. Demographic, histologic, gross endoscopic, and laboratory features were compared using Fisher exact test. RESULTS: Of 475 children with IBD, 8 had concomitant CeD, 5 had tissue transglutaminase (tTG) immunoglobulin A (IgA) > 10x upper limit of normal (ULN, P = 0.006), and 8 had villous atrophy (VA, P = 0.003) when compared with 17 seropositive participants with IBD-only. No children with IBD-CeD had esophageal eosinophilia, duodenal cryptitis, duodenal ulceration, or fecal calprotectin >250 µg/g. Factors that contributed to provider uncertainty for diagnosing CeD in IBD included the absence of VA and intraepithelial lymphocytes, the presence of neutrophilic and eosinophilic duodenitis, diffuse ulceration, elevated inflammatory markers, and immunosuppression therapy. CONCLUSIONS: Diagnosing CeD in children with IBD continues to be challenging. Although high titers of tTG IgA and VA increased provider confidence for diagnosing CeD in IBD, development of evidence-based guidelines are needed. They should better assess the importance of features atypical of concomitant CeD that contribute to uncertainty.


Assuntos
Doença Celíaca , Doenças Inflamatórias Intestinais , Humanos , Doença Celíaca/complicações , Doença Celíaca/diagnóstico , Estudos Retrospectivos , Duodeno/patologia , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/patologia , Autoanticorpos , Imunoglobulina A , Transglutaminases
20.
Emerg Infect Dis ; 27(2): 603-607, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33496217

RESUMO

Anopheles stephensi mosquitoes, efficient vectors in parts of Asia and Africa, were found in 75.3% of water sources surveyed and contributed to 80.9% of wild-caught Anopheles mosquitoes in Awash Sebat Kilo, Ethiopia. High susceptibility of these mosquitoes to Plasmodium falciparum and vivax infection presents a challenge for malaria control in the Horn of Africa.


Assuntos
Anopheles , Plasmodium vivax , Animais , Ásia , Etiópia , Mosquitos Vetores , Plasmodium falciparum
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