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1.
Annu Rev Phys Chem ; 75(1): 483-508, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38941528

RESUMO

Crystallographic analysis relies on the scattering of quanta from arrays of atoms that populate a repeating lattice. While large crystals built of lattices that appear ideal are sought after by crystallographers, imperfections are the norm for molecular crystals. Additionally, advanced X-ray and electron diffraction techniques, used for crystallography, have opened the possibility of interrogating micro- and nanoscale crystals, with edges only millions or even thousands of molecules long. These crystals exist in a size regime that approximates the lower bounds for traditional models of crystal nonuniformity and imperfection. Accordingly, data generated by diffraction from both X-rays and electrons show increased complexity and are more challenging to conventionally model. New approaches in serial crystallography and spatially resolved electron diffraction mapping are changing this paradigm by better accounting for variability within and between crystals. The intersection of these methods presents an opportunity for a more comprehensive understanding of the structure and properties of nanocrystalline materials.

2.
ACS Appl Mater Interfaces ; 16(26): 33461-33474, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38888106

RESUMO

The synthesis, physicochemical, and functional properties of composite solids resulting from the surface spread of oxidized indium species onto nanoplatelets of anatase were investigated. Both the size and the interaction between the indium- and titanium-containing components control the functional properties. In the reduction of CO2 to CO, the best samples have an indium content between ca. 2 and 5 mol % and showed an excess rate over the photo and thermo-alone processes above 33% and an energy efficiency of 1.3%. Subnanometric (monomeric and dimeric) indium species present relatively weak thermal catalytic response but strong thermo-photo promotion of the activity. A gradual change in functional properties was observed with the growth of the indium content of the solids, leading to a progressive increase of thermal activity but lower thermo-photo promotion. The study provides a well-defined structure-activity relationship rationalizing the dual thermo-photo properties of the catalysts and establishes a guide for the development of highly active and stable composite solids for the elimination and valorization of CO2.

3.
J Am Chem Soc ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38859684

RESUMO

Reducing iridium (Ir) catalyst loading for acidic oxygen evolution reaction (OER) is a critical strategy for large-scale hydrogen production via proton exchange membrane (PEM) water electrolysis. However, simultaneously achieving high activity, long-term stability, and reduced material cost remains challenging. To address this challenge, we develop a framework by combining density functional theory (DFT) prediction using model surfaces and proof-of-concept experimental verification using thin films and nanoparticles. DFT results predict that oxidized Ir monolayers over titanium nitride (IrOx/TiN) should display higher OER activity than IrOx while reducing Ir loading. This prediction is verified by depositing Ir monolayers over TiN thin films via physical vapor deposition. The promising thin film results are then extended to commercially viable powder IrOx/TiN catalysts, which demonstrate a lower overpotential and higher mass activity than commercial IrO2 and long-term stability of 250 h to maintain a current density of 10 mA cm-2. The superior OER performance of IrOx/TiN is further confirmed using a proton exchange membrane water electrolyzer (PEMWE), which shows a lower cell voltage than commercial IrO2 to achieve a current density of 1 A cm-2. Both DFT and in situ X-ray absorption spectroscopy reveal that the high OER performance of IrOx/TiN strongly depends on the IrOx-TiN interaction via direct Ir-Ti bonding. This study highlights the importance of close interaction between theoretical prediction based on mechanistic understanding and experimental verification based on thin film model catalysts to facilitate the development of more practical powder IrOx/TiN catalysts with high activity and stability for acidic OER.

4.
J Phys Chem Lett ; 15(23): 6209-6215, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38838247

RESUMO

Palladium catalysts are frequently employed in processes where methanol is an energy vector or carrier, being useful for the synthesis of methanol from mixtures of carbon dioxide and hydrogen (CO2/H2) or its steam reforming on demand. Results of synchrotron-based ambient pressure X-ray photoelectron spectroscopy for the adsorption of methanol on a Pd(111) model catalyst show a rich surface chemistry and complex phenomena that strongly depend on pressure and temperature. At low pressures (<10-6 Torr) and temperatures (<300 K), CO is the dominant decomposition product. As the pressure increases, cleavage of C-H, O-H, and C-O bonds is observed, and at elevated temperatures (400-600 K) the formation of CO and CHx/C fragments compete on the surface. Thus, existing reaction networks for methanol decomposition must be modified. Furthermore, surface and subsurface hydrogen (coming from PdHx) play a significant role in the stability and removal of CHx and C species.

5.
J Arthroplasty ; 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38797448

RESUMO

BACKGROUND: Venous thromboembolism (VTE) poses a major clinical concern due to its life-threatening nature, and obese and morbidly obese patients are thought to be at an increased risk for VTE. The aims of this study were twofold; first, to explore VTE rates in patients who have a body mass index (BMI) > 40 undergoing primary and revision total joint arthroplasty, and second, to investigate aspirin (ASA) efficacy and safety. METHODS: We identified all patients (n = 4,672) who had a BMI > 40 who underwent primary and revision total joint arthroplasty from 2016 to 2022 at a single academic tertiary care center. Patients were stratified by BMI groups: 40 to 44.9 (n = 3,462), 45 to 49.9 (n = 935), and 50+ (n = 275). The primary outcome was any VTE event within 90 days postoperatively. The secondary outcome consisted of wound complications within 90 days postoperatively. RESULTS: The total VTE rate was 0.4% (n = 21) and did not differ statistically between the BMI groups (0.4 versus 0.4 versus 0.7%, P = .669). The VTEs consisted of 6 deep venous thromboses (DVTs), 14 pulmonary embolisms, and one concomitant deep venous thrombosis and pulmonary embolism. The VTE rates were not statistically different between patients who received aspirin 325 mg 0.5% (n = 9), aspirin 81 mg 0.2% (n = 1), aspirin + anticoagulant (AC) 0.5% (n = 6), and AC alone 0.4% (n = 5) (P = .954). In addition, wound complications did not differ significantly between patients who received ASA 325 mg, ASA 81mg, ASA + AC, or AC alone (1.6 versus 1.0 versus 1.8 versus 1.1%, P = .351). CONCLUSIONS: The use of aspirin 325 and 81 mg was found to have similar VTE rates as aspirin + ACs and ACs alone, with no significant increase in wound complications. In patients who have a BMI > 40, the use of aspirin is a safe option for VTE prophylaxis and should be prescribed in the context of the patient who has other risk factors for VTE.

6.
Anal Methods ; 16(23): 3675-3683, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38804529

RESUMO

Determination of digoxin through in-capillary derivatisation based on the formation of o-tolyl- and 2-naphthyl-anionic boronate esters in combination with large volume sample stacking-capillary electrophoresis is proposed. The derivatisation reaction was performed at basic pH values to obtain compounds with a charge and chromophore group during the stacking process. After stacking, the species were separated and detected at 225 nm using p-nitrophenol as an internal standard. Stacking and derivatisation parameters such as pre-concentration time, preconcentration voltage and injection time (relation between the analyte and the derivatisation agent) were evaluated using a Box-Behnken design. Under optimal conditions, the proposed method exhibits a linear range of 1.08-50.00 µM with a limit of detection of 0.36 µM; additionally, adequate repeatability and reproducibility was obtained (%RSD ≤ 5.0%). The methodology was validated by comparing it to an HPLC-UV established methodology and was successfully applied for the determination of digoxin in pharmaceutical tablets and blood serum samples, showing a positive performance for these matrices.


Assuntos
Ácidos Borônicos , Digoxina , Eletroforese Capilar , Digoxina/sangue , Digoxina/análise , Digoxina/química , Eletroforese Capilar/métodos , Ácidos Borônicos/química , Humanos , Ésteres/química , Limite de Detecção , Reprodutibilidade dos Testes , Comprimidos
7.
J Orthop Res ; 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38669091

RESUMO

Patient-specific flanged acetabular components are utilized to treat failed total hip arthroplasties with large acetabular defects. Previous clinical studies from our institution showed that these implants tend to lateralize the acetabular center of rotation. However, the clinical impact of lateralization on implant survivorship is debated. Our goal was to develop a finite element model to quantify how lateralization of the native hip center affects periprosthetic strain and implant-bone micromotion distributions in a static level gait loading condition. To build the model, we computationally created a superomedial acetabular defect in a computed tomography 3D reconstruction of a native pelvis and designed a flanged acetabular implant to address this simulated bone defect. We modeled two implants, one with ~1 cm and a second with ~2 cm of hip center lateralization. We applied the maximum hip contact force and corresponding abductor force observed during level gait. The resulting strains were compared to bone fatigue strength (0.3% strain) and the micromotions were compared to the threshold for bone ingrowth (20 µm). Overall, the model demonstrated that the additional lateralization only slightly increased the area of bone at risk of failure and decreased the areas compatible with bone ingrowth. This computational study of patient-specific acetabular implants establishes the utility of our modeling approach. Further refinement will yield a model that can explore a multitude of variables and could be used to develop a biomechanically-based acetabular bone loss classification system to guide the development of patient-specific implants in the treatment of large acetabular bone defects.

8.
PLoS One ; 19(4): e0297327, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38687734

RESUMO

The Coronavirus Disease 2019 (COVID-19) pandemic has disproportionately impacted people who use drugs (PWUD). This study explored relationships between drug use, COVID-19 testing, vaccination, and infection. This cross-sectional study was conducted in Miami, Florida between March 2021 and October 2022 as part of the National Institutes of Health (NIH) Rapid Acceleration of Diagnostics-Underserved Populations (RADx-UP) initiative and the Miami Adult Studies on HIV (MASH) cohort. Users of cannabis, cocaine/crack, heroin/fentanyl, methamphetamines, hallucinogens, and/or prescription drug misuse in the previous 12 months were considered PWUD. Sociodemographic data, COVID-19 testing history, and vaccination-related beliefs were self-reported. Vaccinations were confirmed with medical records and positivity was determined with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing. Statistical analyses included chi-square tests and logistic regression. Of 1,780 participants, median age was 57 years, 50.7% were male, 50.2% Non-Hispanic Black, and 66.0% reported an annual income less than $15,000. Nearly 28.0% used drugs. PWUD were less likely than non-users to self-report ever testing positive for SARS-CoV-2 (14.7% vs. 21.0%, p = 0.006). However, 2.6% of participants tested positive for SARS-CoV-2, with no significant differences between PWUD and non-users (3.7% vs. 2.2%, p = 0.076). PWUD were more likely than non-users to experience difficulties accessing testing (10.2% vs. 7.1%, p = 0.033), vaccine hesitancy (58.9% vs. 43.4%, p = 0.002) and had lower odds of receiving any dose of a COVID-19 vaccine compared to non-users (aOR, 0.63; 95% CI, 0.49-0.81; p<0.001). PWUD presented with greater difficulties accessing COVID-19 testing, greater vaccine hesitancy, and lower odds of vaccination. Testing and immunization plans that are tailored to the needs of PWUD and consider access, trust-building campaigns, and education may be needed.


Assuntos
Teste para COVID-19 , COVID-19 , SARS-CoV-2 , Vacinação , Humanos , Florida/epidemiologia , Masculino , COVID-19/prevenção & controle , COVID-19/epidemiologia , Feminino , Pessoa de Meia-Idade , Estudos Transversais , Adulto , Vacinação/estatística & dados numéricos , SARS-CoV-2/isolamento & purificação , Teste para COVID-19/estatística & dados numéricos , Idoso , Grupos Minoritários/estatística & dados numéricos , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Usuários de Drogas/psicologia , Usuários de Drogas/estatística & dados numéricos , Vacinas contra COVID-19/administração & dosagem
9.
Int J Mol Sci ; 25(8)2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38673963

RESUMO

Accurate etiologic diagnosis provides an appropriate secondary prevention and better prognosis in ischemic stroke (IS) patients; still, 45% of IS are cryptogenic, urging us to enhance diagnostic precision. We have studied the transcriptomic content of plasma extracellular vesicles (EVs) (n = 21) to identify potential biomarkers of IS etiologies. The proteins encoded by the selected genes were measured in the sera of IS patients (n = 114) and in hypertensive patients with (n = 78) and without atrial fibrillation (AF) (n = 20). IGFBP-2, the most promising candidate, was studied using immunohistochemistry in the IS thrombi (n = 23) and atrium of AF patients (n = 13). In vitro, the IGFBP-2 blockade was analyzed using thromboelastometry and endothelial cell cultures. We identified 745 differentially expressed genes among EVs of cardioembolic, atherothrombotic, and ESUS groups. From these, IGFBP-2 (cutoff > 247.6 ng/mL) emerged as a potential circulating biomarker of embolic IS [OR = 8.70 (1.84-41.13) p = 0.003], which was increased in patients with AF vs. controls (p < 0.001) and was augmented in cardioembolic vs. atherothrombotic thrombi (p < 0.01). Ex vivo, the blockage of IGFBP-2 reduced clot firmness (p < 0.01) and lysis time (p < 0.001) and in vitro, diminished endothelial permeability (p < 0.05) and transmigration (p = 0.06). IGFBP-2 could be a biomarker of embolic IS and a new therapeutic target involved in clot formation and endothelial dysfunction.


Assuntos
Biomarcadores , Vesículas Extracelulares , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina , AVC Isquêmico , Trombose , Humanos , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/genética , Biomarcadores/sangue , Masculino , Feminino , Idoso , Trombose/metabolismo , Trombose/etiologia , Trombose/sangue , AVC Isquêmico/metabolismo , AVC Isquêmico/sangue , AVC Isquêmico/genética , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Pessoa de Meia-Idade , Perfilação da Expressão Gênica , Transcriptoma , Fibrilação Atrial/metabolismo , Fibrilação Atrial/genética , Fibrilação Atrial/complicações , Fibrilação Atrial/sangue
10.
J Arthroplasty ; 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38631514

RESUMO

BACKGROUND: Instability following total knee arthroplasty (TKA) is a common cause for revision. Isolated polyethylene exchange (IPE) can be performed to increase knee joint stability, but results have been mixed. The purpose of this study was to compare the survivorship and patient-reported outcomes of patients undergoing revision TKA for instability with IPE versus full component revision. METHODS: We reviewed 280 primary TKAs undergoing revision TKA for instability. There were 181 knees that underwent revision with IPE, compared to 99 knees treated with full component revision. The mean follow-up was 32.8 months (range, 24.8 to 82.5). Patient demographics, radiographic parameters, prosthesis constraints, reoperations for instability, and patient-reported outcomes were compared. RESULTS: The survivorship for instability was significantly higher at 2 years (99 versus 92%, P = .024) and 5 years (94 versus 84%, P = .024) for patients undergoing full component revision. Although there was no difference in Knee Injury and Osteoarthritis Outcome Score for Joint Replacements and Veterans RAND 12 physical component scores between the 2 groups at 6 weeks, 1 year, and 2 years after surgery, full revision patients reported greater pain relief (P = .006) and greater improvements in Veterans RAND 12 physical component scores (P = .027) at 1 year and Knee Injury and Osteoarthritis Outcome Score for Joint Replacements scores at 2 years (P = .017) compared to IPE patients. Men were associated with an increased risk for recurrent instability following IPE (hazard ratio 3.3, 95% confidence interval: [1.0 to 10.6]). CONCLUSIONS: Isolated polyethylene exchange was not as reliable or durable compared to full component revision for the management of postoperative instability. These procedures should only be reserved in cases with competent collaterals and when component position, offset, and rotation are optimized.

12.
J Arthroplasty ; 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38677347

RESUMO

BACKGROUND: Cefazolin is the standard of care for perioperative antibiotic prophylaxis in total joint arthroplasty (TJA) in the United States. The potential allergic cross-reactivity between cefazolin and penicillin causes uncertainty regarding optimal antibiotic choice in patients who have a reported penicillin allergy (rPCNA). The purpose of this study was to determine the safety of perioperative cefazolin in PCNA patients undergoing primary TJA. METHODS: We identified all patients (n = 49,842) undergoing primary total hip arthroplasty (n = 25,659) or total knee arthroplasty (n = 24,183) from 2016 to 2022 who received perioperative intravenous antibiotic prophylaxis. Patients who had an rPCNA (n = 5,508) who received cefazolin (n = 4,938, 89.7%) were compared to rPCNA patients who did not (n = 570, 10.3%), and to patients who did not have an rPCNA (n = 43,359). The primary outcome was the rate of allergic reactions within 72 hours postoperatively. Secondary outcomes included the rates of superficial infections, deep infections, and Clostridioides difficile infections within 90 days. RESULTS: The rate of allergic reactions was 0.1% (n = 5) in rPCNA patients who received cefazolin, compared to 0.2% (n = 1) in rPCNA patients who did not (P = .48) and 0.02% (n = 11) in patients who have no rPCNA (P = .02). Allergic reactions were mild in all 5 rPCNA patients who received cefazolin and were characterized by cutaneous symptoms (n = 4) or dyspnea in the absence of respiratory distress (n = 1) that resolved promptly with antibiotic discontinuation and administration of antihistamines and/or corticosteroids. We observed no differences in the rates of superficial infections (0.1 versus 0.2%, P = .58), deep infections (0.3 versus 0.4%, P = .68), or C difficile infections (0.04% versus 0%, P = .99) within 90 days in rPCNA patients who received cefazolin versus alternative perioperative antibiotics. CONCLUSIONS: In this series of more than 5,500 patients who had an rPCNA undergoing primary TJA, perioperative prophylaxis with cefazolin resulted in a 0.1% incidence of allergic reactions that were clinically indolent. Cefazolin can be safely administered to most patients, independent of rPCNA severity. LEVEL OF EVIDENCE: III.

13.
Pediatr Allergy Immunol ; 35(4): e14129, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38664926

RESUMO

Monitoring is a major component of asthma management in children. Regular monitoring allows for diagnosis confirmation, treatment optimization, and natural history review. Numerous factors that may affect disease activity and patient well-being need to be monitored: response and adherence to treatment, disease control, disease progression, comorbidities, quality of life, medication side-effects, allergen and irritant exposures, diet and more. However, the prioritization of such factors and the selection of relevant assessment tools is an unmet need. Furthermore, rapidly developing technologies promise new opportunities for closer, or even "real-time," monitoring between visits. Following an approach that included needs assessment, evidence appraisal, and Delphi consensus, the PeARL Think Tank, in collaboration with major international professional and patient organizations, has developed a set of 24 recommendations on pediatric asthma monitoring, to support healthcare professionals in decision-making and care pathway design.


Assuntos
Asma , Humanos , Asma/diagnóstico , Asma/terapia , Criança , Qualidade de Vida , Antiasmáticos/uso terapêutico , Técnica Delphi , Monitorização Fisiológica/métodos
14.
Curr Opin Neurobiol ; 86: 102857, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38489865

RESUMO

The concept of 'prion-like' behavior has emerged in the study of diseases involving protein misfolding where fibrillar structures, called amyloids, self-propagate and induce disease in a fashion similar to prions. From a biological standpoint, in order to be considered 'prion-like,' a protein must traverse cells and tissues and further propagate via a templated conformational change. Since 2017, cryo-electron microscopy structures from patient-derived 'prion-like' amyloids, in particular tau, have been presented and revealed structural similarities shared across amyloids. Since 2021, cryo-EM structures from prions of known infectivity have been added to the ex vivo amyloid structure family. In this review, we discuss current proposals for the 'prion-like' mechanisms of spread for tau and prion protein as well as discuss different influencers on structures of aggregates from tauopathies and prion diseases. Lastly, we discuss some of the current hypotheses for what may distinguish structures that are 'prion-like' from transmissible prion structures.


Assuntos
Proteínas Priônicas , Proteínas tau , Humanos , Proteínas tau/metabolismo , Proteínas tau/química , Animais , Proteínas Priônicas/metabolismo , Proteínas Priônicas/química , Doenças Priônicas/metabolismo , Doenças Priônicas/patologia , Tauopatias/metabolismo , Tauopatias/patologia , Príons/metabolismo , Príons/química , Amiloide/metabolismo , Amiloide/química
15.
J Arthroplasty ; 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38537838

RESUMO

BACKGROUND: Dislocation after total hip arthroplasty (THA) is a primary reason for THA revision. During THA through the direct anterior approach (DAA), the iliofemoral ligament, which provides the main resistance to external rotation (ER) of the hip, is commonly partially transected. We asked: (1) what is the contribution of the medial iliofemoral ligament to resisting ER after DAA THA? and (2) how much resistance to ER can be restored by repairing the ligament? METHODS: A fellowship-trained surgeon performed DAA THA on 9 cadaveric specimens. The specimens were computed tomography scanned before and after implantation. Prior to testing, the ER range of motion of each specimen to impingement in neutral and 10° of extension was computationally predicted. Each specimen was tested on a 6-degrees-of-freedom robotic manipulator. The pelvis was placed in neutral and 10° of extension. The femur was externally rotated until it reached the specimen's impingement target. Total ER torque was recorded with the medial iliofemoral ligament intact, after transecting the ligament, and after repair. Torque at extremes of motion was calculated for each condition. To isolate the contribution of the native ligament, the torque for the transected state was subtracted from both the native and repaired conditions. RESULTS: The medial iliofemoral ligament contributed an average of 68% (range, 34 to 87) of the total torque at the extreme of motion in neutral and 80% (58 to 97) in 10° of extension. The repaired ligament contributed 17% (1 to 54) of the total torque at the extreme of motion in neutral and 14% (5 to 38) in 10° of extension, restoring on average 18 to 25% of the native resistance against ER. CONCLUSIONS: The medial iliofemoral ligament was an important contributor to the hip torque at the extreme of motion during ER. Repairing the ligament restored a fraction of its ability to generate torque to resist ER.

16.
ACS Macro Lett ; 13(4): 423-428, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38529829

RESUMO

We report a unique method to construct hierarchical superstructures based on molecular programming of peptidomimetics. Chiral steric hindrance in the polymer backbone stabilizes peptoid helices that crystallize into nanosheets during solvent evaporation. The stacking of nanosheets results in flower-like superstructures. The helical peptoid, nucleated from chiral monomers, is characterized as locally stiffer and more extended than the unstructured peptoid. Molecular dynamics (MD) simulations further suggest a constraint on the dihedral angles and a preference toward the trans configuration, resulting in an extended chain structure. The nanosheet assemblies at various length scales indicate an extent of intermolecular ordering amplified by chiral steric hindrance. Such molecular programming and processing protocols will benefit the future design and controlled assembly of hierarchical peptidomimetics.

17.
J Asthma ; : 1-7, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38426671

RESUMO

INTRODUCTION: Reactance inversion (RI) has been associated with impaired peripheral airway function in persistent asthma. However, there is little to no data about the difference between asthmatic children with and without RI. This study aimed to detect clinical and lung function differences in moderate-severe asthmatic children with and without RI. METHODS: This study was conducted between 2021 and 2022 in asthmatic school-age children. Impulse oscillometry (IOS) and spirometry were performed according to ATS/ERS standards. RESULTS: A total of 62 patients, with a mean age of 8.4 years, 54.8% were males and were divided into three groups: group 1 (32.3%) with no RI, group 2 (27.4%) with RI but disappearing after bronchodilator test and group 3 (40.3%) with persistent RI after bronchodilator test. Children in groups 2 and 3 had significantly lower birth weights than in group 1. Group 2 had lower gestational age compared to group 1. FEV1 and FEF25-75 of forced vital capacity were significantly lower in groups 2 and 3. In group 3, R5, AX, R5-20, and R5-R20/R5 ratios were significantly higher. Bronchodilator responses (BDR) in X5c, AX, and R5-R20 were significantly different between groups and lower in group 3. CONCLUSION: RI is frequently found in children with moderate-severe persistent asthma, particularly in those with a history of prematurity or low birth weight. In some patients, RI disappears after the bronchodilator test; however, it, persists in those with the worst pulmonary function. RI could be a small airway dysfunction marker.

18.
Acta Crystallogr D Struct Biol ; 80(Pt 4): 270-278, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38451205

RESUMO

Macromolecular crystallography generally requires the recovery of missing phase information from diffraction data to reconstruct an electron-density map of the crystallized molecule. Most recent structures have been solved using molecular replacement as a phasing method, requiring an a priori structure that is closely related to the target protein to serve as a search model; when no such search model exists, molecular replacement is not possible. New advances in computational machine-learning methods, however, have resulted in major advances in protein structure predictions from sequence information. Methods that generate predicted structural models of sufficient accuracy provide a powerful approach to molecular replacement. Taking advantage of these advances, AlphaFold predictions were applied to enable structure determination of a bacterial protein of unknown function (UniProtKB Q63NT7, NCBI locus BPSS0212) based on diffraction data that had evaded phasing attempts using MIR and anomalous scattering methods. Using both X-ray and micro-electron (microED) diffraction data, it was possible to solve the structure of the main fragment of the protein using a predicted model of that domain as a starting point. The use of predicted structural models importantly expands the promise of electron diffraction, where structure determination relies critically on molecular replacement.


Assuntos
Proteínas de Bactérias , Elétrons , Proteínas de Bactérias/química , Raios X , Conformação Proteica , Cristalografia por Raios X
19.
Paediatr Respir Rev ; 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38395640

RESUMO

BACKGROUND: Asthma is the most prevalent chronic disease in children and constitutes a significant healthcare burden. First-line therapy for acute asthma exacerbations is well established. However, secondary treatments, including intravenous magnesium sulfate (IV-MgSO4), remain variable due to scarcity of data on its efficacy and safety. OBJECTIVE: To assess the effectiveness and safety of IV-MgSO4 as a second line of treatment in managing children with asthma exacerbations. METHODS: We searched five databases from inception until April 2023 on randomized clinical trials of IV-MgSO4 in children with acute asthma exacerbations. The primary outcomes were hospitalization rate and length, and change in the severity score. Secondary outcomes included percentage increase in peak expiratory flow rate (PEFR), hospital re-admission rate, need and length for pediatric intensive care unit (PICU) treatment, and adverse effects. Meta-analysis was performed for three outcomes with estimated odds ratios (ORs) or mean differences (MDs) and 95% confidence intervals (CIs). RESULTS: Eleven studies met the final criteria. In comparison to control, administration of IV-MgSO4 was associated with a reduced hospitalization risk (OR 0.15; 95%CI: 0.03, 0.73) in four studies, and improvement of lung function (MD 26.77% PEFR; 95%CI: 18.41, 54.79) in two studies. There were no significant differences in the length of stay between groups. Due to heterogeneity, a narrative synthesis of other outcomes was performed. CONCLUSION: The use of IV-MgSO4 demonstrated a reduction in the hospitalization rate and PEFR improvement in children with asthma exacerbations. Adverse effects were rare. Further well-designed studies are needed to better determine the efficacy and safety profile of IV-MgSO4.

20.
Sensors (Basel) ; 24(3)2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38339537

RESUMO

The application of deep learning to image and video processing has become increasingly popular nowadays. Employing well-known pre-trained neural networks for detecting and classifying objects in images is beneficial in a wide range of application fields. However, diverse impediments may degrade the performance achieved by those neural networks. Particularly, Gaussian noise and brightness, among others, may be presented on images as sensor noise due to the limitations of image acquisition devices. In this work, we study the effect of the most representative noise types and brightness alterations on images in the performance of several state-of-the-art object detectors, such as YOLO or Faster-RCNN. Different experiments have been carried out and the results demonstrate how these adversities deteriorate their performance. Moreover, it is found that the size of objects to be detected is a factor that, together with noise and brightness factors, has a considerable impact on their performance.

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