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1.
Cryst Growth Des ; 24(12): 5276-5284, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38911134

RESUMO

Disorder is a common feature of molecular crystals that complicates determination of structures and can potentially affect electric and mechanical properties. Suppression of disorder is observed in otherwise severely disordered benzamide and thiobenzamide crystals by substituting hydrogen with fluorine in the ortho-position of the phenyl ring. Fluorine occupancies of 20-30% are sufficient to suppress disorder without changing the packing motif. Crystal structure prediction calculations reveal a much denser lattice energy landscape for benzamide compared to 2-fluorobenzamide, suggesting that fluorine substitution makes disorder less likely.

2.
Cryst Growth Des ; 24(10): 4195-4212, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38766642

RESUMO

The dapsone/flavone cocrystal system served as a benchmark for both experimental and virtual screening methods. Expanding beyond this, two additional active pharmaceutical ingredients (APIs), sulfanilamide and sulfaguanidine, structurally related to dapsone were chosen to investigate the impact of substituents on cocrystal formation. The experimental screening involved mechanochemical methods, slurry experiments, hot-melt extrusion, and the contact preparation method. The virtual screening focused on crystal structure prediction (CSP), molecular complementarity, hydrogen-bond propensity, and molecular electrostatic potentials. The CSP studies not only indicated that each of the three APIs should form cocrystals with flavone but also reproduced the known single- and multicomponent phases. Experimentally, dapsone/flavone cocrystals ACC, BCC, CCC, and DCC were reproduced, CCC was identified as a nonstoichiometric hydrate, and a fifth cocrystal (ECC), a t-butanol solvate, was discovered. The cocrystal polymorphs ACC and BCC are enantiotripically related, and DCC, exhibiting a different stoichiometric ratio, is enthalpically stabilized over the other cocrystals. For the sulfaguanidine/flavone system, two novel, enantiotripically related cocrystals were identified. The crystal structures of two cocrystals and a flavone polymorph were solved from powder X-ray diffraction data, and the stability of all cocrystals was assessed through differential scanning calorimetry and lattice energy calculations. Despite computational indications, a diverse array of cocrystallization techniques did not result in a sulfanilamide/flavone cocrystal. The driving force behind dapsone's tendency to cocrystallize with flavone can be attributed to the overall strength of flavone interactions in the cocrystals. For sulfaguanidine, the potential to form strong API···API and API···coformer interactions in the cocrystal is a contributing factor. Furthermore, flavone was found to be trimorphic.

3.
Cureus ; 16(3): e55958, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38601425

RESUMO

BACKGROUND: Over nearly three decades, Ecuador experienced a significant rise in adolescent motherhood. OBJECTIVES: By focusing on social, health, and psychological aspects, the research aims to reveal the complex factors influencing the decision to discontinue education. The emphasis on providing a platform for direct expression of personal experiences not only adds qualitative depth to the study but also ensures that the voices of those involved are heard authentically. METHODS: Employing a nonexperimental, descriptive, cross-sectional approach with qualitative and quantitative methods, the research delves into the interplay of biological, psychological, and social factors. Descriptive statistics, presented through tables and graphs, were used for variable analysis, complemented by inferential statistics to validate hypotheses. Focus group sessions, processed with ATLAS.ti (ATLAS.ti Scientific Software Development GmbH, Berlin, Germany) underwent a thorough review in workshops with Servicio de Atención Integral para Adolescentes (SAIA) experts. Adolescent participants were randomly recruited through the hospital's system. RESULTS: The findings unveiled a significant dropout rate among adolescents, where pregnancy was just one factor influencing their decision. Those discontinuing education often embraced a life project centered on motherhood and domestic roles, facing domestic violence and mental health disorders. In contrast, those persisting with education were driven by professional development, facing challenges but benefiting from family support. Despite unwanted pregnancies and low contraceptive use, many found personal growth and identity affirmation in motherhood. CONCLUSIONS: Our research highlights key insights into factors like pregnancy desire, contraception, reactions, and challenges. Urgent action is needed to address systemic problems and provide holistic support, acknowledging the resilience and validity of choices made by adolescent mothers in balancing motherhood with education and career goals.

4.
Abdom Radiol (NY) ; 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38615061

RESUMO

OBJECTIVE: Retrospectively evaluate multimodality imaging features of perinephric myxoid pseudotumor of fat (PMPTF). METHODS: Institutional cases of PMPTF with CT, MRI and/or ultrasound evaluation from 1/1/2020 to 9/1/2023 were retrospectively reviewed. Patient demographics and clinical history were reviewed, and imaging features recorded. RESULTS: 14 patients with pathologically-proven PMPTF were identified (11 M, 3 F; mean age 66.7 ± 17.0 years; range 40-87 years). Three patients (18%) had bilateral lesions; a total of 17 PMPTFs were reviewed. 15/17 (88%) were biopsy-proven; two cases were diagnosed by imaging only in patients with a contralateral biopsy-proven PMPTF. All evaluable specimens were negative for MDM2 amplification. 11/17 (65%) occurred in patients with renal disease, including 4/17 (24%) in patients with renal transplant. 100% (17/17) had CT, 11/17 (65%) MRI, and 6/17 (35%) ultrasound. The mean largest lesion dimension was 10.9 ± 4.6 cm (range 4.3-17.0 cm). Of cases involving native kidneys, 7/13 (54%) presented as multifocal perinephric masses and 5/13 (38%) as a solitary perinephric mass. All four transplant cases presented as infiltrative-appearing masses involving the renal sinus with lesser perinephric involvement. 14/17 (82%) lesions contained macroscopic fat on CT and MRI and 3/17 (18%) showed no macroscopic fat, all involving renal transplants. All cases with MRI demonstrated T2 hyperintensity with signal dropout on opposed-phase imaging. 11/13 (85%) PMPTF showed no or equivocal CT enhancement. Enhancement was better seen on MRI in all cases evaluated by both CT and MRI. Of the six PMPTFs imaged by ultrasound, four (67%) were heterogeneously hypoechoic and two (33%) had mixed regions of hypo-, iso- and hyperechogenicity relative to adjacent renal parenchyma. CONCLUSIONS: PMPTF is a rare, benign, and underrecognized lesion that may mimic malignancy, particularly retroperitoneal well-differentiated liposarcoma. The imaging features of this unusual pseudosarcoma differ in native and transplanted kidneys. Improved awareness of this entity will facilitate appropriate patient management and avoid unnecessary intervention.

5.
Contemp Clin Trials ; 141: 107522, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38580104

RESUMO

BACKGROUND: Elevated depression symptoms have been associated with higher insulin resistance in adolescents, and consequently, greater risk for type 2 diabetes (T2D). Mindfulness-based intervention (MBI) may be suited for adolescents at risk for T2D given its potential to decrease depression and improve stress-related behavior/physiology underpinning insulin resistance. To prepare for a future multisite efficacy randomized controlled trial, a rigorous, multisite, pilot and feasibility study is needed to test this approach. The current paper describes the design and protocol for a multisite, pilot and feasibility randomized controlled trial of six-week MBI, cognitive-behavioral therapy (CBT), and health education (HealthEd) group interventions, to assess multisite fidelity, feasibility, and acceptability. METHODS: Participants are N = 120 adolescents ages 12-17, with body mass index (BMI) ≥85th percentile, elevated depression symptoms (20-item Center for Epidemiologic Studies-Depression Scale total score > 20), and family history of diabetes. Enrollment occurs across four United States (US) sites, two in Colorado, one in Washington, D·C., and one in Maryland. Group interventions are delivered virtually by trained psychologists and co-facilitators. Assessments occur at baseline, six-week follow-up, and one-year follow-up. RESULTS: Primary outcomes are intervention implementation fidelity, based upon expert ratings of audio-recorded sessions (≥80% adherence/competence), and recruitment feasibility, based upon percentage enrollment of eligible youth (≥80%). Secondary outcomes are intervention training fidelity/feasibility/acceptability, recruitment timeframe, and retention/assessment feasibility. CONCLUSION: Findings will inform optimization of training, recruitment, intervention delivery, retention, and assessment protocols for a multisite, efficacy randomized controlled trial evaluating MBI for decreasing depression and improving insulin resistance in adolescents at risk for developing T2D.


Assuntos
Terapia Cognitivo-Comportamental , Depressão , Diabetes Mellitus Tipo 2 , Estudos de Viabilidade , Resistência à Insulina , Atenção Plena , Adolescente , Criança , Feminino , Humanos , Masculino , Índice de Massa Corporal , Terapia Cognitivo-Comportamental/métodos , Depressão/terapia , Diabetes Mellitus Tipo 2/terapia , Diabetes Mellitus Tipo 2/psicologia , Educação em Saúde/organização & administração , Educação em Saúde/métodos , Atenção Plena/métodos , Projetos Piloto , Estudos Multicêntricos como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto
6.
Commun Biol ; 7(1): 316, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38480906

RESUMO

Warming can have profound impacts on ecological communities. However, explorations of how differences in biogeography and productivity might reshape the effect of warming have been limited to theoretical or proxy-based approaches: for instance, studies of latitudinal temperature gradients are often conflated with other drivers (e.g., species richness). Here, we overcome these limitations by using local geothermal temperature gradients across multiple high-latitude stream ecosystems. Each suite of streams (6-11 warmed by 1-15°C above ambient) is set within one of five regions (37 streams total); because the heating comes from the bedrock and is not confounded by changes in chemistry, we can isolate the effect of temperature. We found a negative overall relationship between diatom and invertebrate species richness and temperature, but the strength of the relationship varied regionally, declining more strongly in regions with low terrestrial productivity. Total invertebrate biomass increased with temperature in all regions. The latter pattern combined with the former suggests that the increased biomass of tolerant species might compensate for the loss of sensitive species. Our results show that the impact of warming can be dependent on regional conditions, demonstrating that local variation should be included in future climate projections rather than simply assuming universal relationships.


Assuntos
Ecossistema , Rios , Animais , Biomassa , Biodiversidade , Invertebrados
7.
Cryst Growth Des ; 24(3): 1438-1457, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38344672

RESUMO

A thorough re-examination of sulfaguanidine's (SGD) solid-state behavior was conducted, 65 years after the initial report on SGD polymorphism. This investigation focuses on the polymorphic nature of the compound, the formation of hydrates and solvates, and the pivotal role of experimental and computational methods in screening, assessing stability, and understanding transformation processes. The findings confirm the presence of five anhydrates (AH-I-V), two monohydrate polymorphs (Hy1-I and Hy1-II), and nine solvates (with tetrahydrofuran, methanol, ethanol, t-butanol, acetone, cyclohexanone, dimethyl sulfoxide, dimethyl formamide, and dimethyl acetamide). Notably, nine novel structures-two anhydrates and seven solvates-are reported, solved from powder X-ray diffraction data. Calorimetric measurements have revealed that AH-II is the thermodynamically stable polymorph at room and low temperatures. In contrast, AH-I emerges as the stable polymorph at higher temperatures, yet it exhibits remarkable kinetic stability at RT and demonstrates greater stability in terms of hydration. The anhydrate forms exhibit distinctive packing arrangements, while the two hydrates share a close structural resemblance. Among the seven structurally characterized solvates, only the tetrahydrofuran and dimethyl sulfoxide solvates are isostructural. Controlled desolvation experiments enabled the formation of AH-I, AH-II, and, notably, AH-V for the first time. The anhydrate and monohydrate crystal structure prediction studies reveal that the computed lowest-energy structures correspond to experimentally observed forms and propose models for the elusive AH-IV structure. Overall, the exploration of SGD's solid-state landscape confirms a rich array of highly stable H-bonding motifs and packing arrangements, positioning this study as an ideal model for complex solid-state systems and shedding light on its intricate solid-state nature.

8.
Phys Rev Lett ; 132(5): 053602, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38364136

RESUMO

The interaction of a resonant light field with a quantum two-level system is of key interest both for fundamental quantum optics and quantum technological applications employing resonant excitation. While emission under resonant continuous-wave excitation has been well studied, the more complex emission spectrum of dynamically dressed states-a quantum two-level system driven by resonant pulsed excitation-has so far been investigated in detail only theoretically. Here, we present the first experimental observation of the complete resonance fluorescence emission spectrum of a single quantum two-level system, in the form of an excitonic transition in a semiconductor quantum dot, driven by finite Gaussian pulses. We observe multiple emerging sidebands as predicted by theory, with an increase of their number and spectral detuning with excitation pulse intensity and a dependence of their spectral shape and intensity on the pulse length. Detuning-dependent measurements provide additional insights into the emission features. The experimental results are in excellent agreement with theoretical calculations of the emission spectra, corroborating our findings.

9.
J Equine Vet Sci ; 133: 105016, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38281607

RESUMO

Timor ponies (TP) were first shipped to Australia in the early 1800s and were highly valued as transport and pack animals, which resulted in TPs contributing to the development of Australian horse breeds. Today, while the exact number of TPs in Australia is currently unknown, there has been recent interest in establishing a domestic breeding program for Australian TPs. The aim of this study was to evaluate the relatedness of a sample of TPs, as well as provide estimates of genomic inbreeding levels to better inform the feasibility of using these animals as founders for a domestic breeding program. Hair samples from each horse were genotyped using the Illumina 80K Infinium Equine genotyping array and data were analysed using PLINK v1.90b7, KING 2.3.2 and R v4.3.1. The results illustrate that there are distantly related and minimally inbred horses within the sampled TPs. Lengths of the ROH segments also indicated that recent inbreeding events are likely to only have occurred in a third of the horses. Overall, these results are promising for the success of a domestic TP breeding program; however, considering the low number of domestic TPs known to reside in Australia, there would certainly still be substantial benefits to incorporating additional TPs either directly from Timor or from areas in Australia that are believed to contain wild descendants of TPs.


Assuntos
Endogamia , Polimorfismo de Nucleotídeo Único , Cavalos/genética , Animais , Indonésia , Austrália , Genômica/métodos
10.
J Clin Endocrinol Metab ; 109(2): e870-e872, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-37624230

RESUMO

The prevalence of youth-onset type 2 diabetes is growing worldwide and current first-line treatment with metformin and intensive behavior and lifestyle changes are suboptimal in over 50% of youth within 2 years of diagnosis. This perspective article is a call to action for reevaluation of existing strategies and critical appraisal of metformin as first-line therapy in youth-onset type 2 diabetes. Increased attention should be given to novel therapeutics approved in youth, including glucagon-like 1 receptor agonists, sodium glucose cotransporter-2, and sociocultural interventions that will promote diabetes self-management.


Assuntos
Diabetes Mellitus Tipo 2 , Metformina , Humanos , Adolescente , Hipoglicemiantes/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/epidemiologia , Metformina/uso terapêutico , Comportamentos Relacionados com a Saúde , Estilo de Vida
11.
Cryst Growth Des ; 23(11): 8241-8260, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37937188

RESUMO

In this study, key features of metronidazole (MNZ) cocrystal polymorphs with gallic acid (GAL) and gentisic acid (GNT) were elucidated. Solvent-mediated phase transformation experiments in 30 solvents with varying properties were employed to control the polymorphic behavior of the MNZ cocrystal with GAL. Solvents with relative polarity (RP) values above 0.35 led to cocrystal I°, the thermodynamically stable form. Conversely, solvents with RP values below 0.35 produced cocrystal II, which was found to be only 0.3 kJ mol-1 less stable in enthalpy. The feasibility of electrospraying, including solvent properties and process conditions required, and spray drying techniques to control cocrystal polymorphism was also investigated, and these techniques were found to facilitate exclusive formation of the metastable MNZ-GAL cocrystal II. Additionally, the screening approach resulted in a new, high-temperature polymorph I of the MNZ-GNT cocrystal system, which is enantiotropically related to the already known form II°. The intermolecular energy calculations, as well as the 2D similarity between the MNZ-GAL polymorphs and the 3D similarity between MNZ-GNT polymorphs, rationalized the observed transition behaviors. Furthermore, the evaluation of virtual cocrystal screening techniques identified molecular electrostatic potential calculations as a supportive tool for coformer selection.

12.
Nature ; 623(7986): 324-328, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37938708

RESUMO

The physicochemical properties of molecular crystals, such as solubility, stability, compactability, melting behaviour and bioavailability, depend on their crystal form1. In silico crystal form selection has recently come much closer to realization because of the development of accurate and affordable free-energy calculations2-4. Here we redefine the state of the art, primarily by improving the accuracy of free-energy calculations, constructing a reliable experimental benchmark for solid-solid free-energy differences, quantifying statistical errors for the computed free energies and placing both hydrate crystal structures of different stoichiometries and anhydrate crystal structures on the same energy landscape, with defined error bars, as a function of temperature and relative humidity. The calculated free energies have standard errors of 1-2 kJ mol-1 for industrially relevant compounds, and the method to place crystal structures with different hydrate stoichiometries on the same energy landscape can be extended to other multi-component systems, including solvates. These contributions reduce the gap between the needs of the experimentalist and the capabilities of modern computational tools, transforming crystal structure prediction into a more reliable and actionable procedure that can be used in combination with experimental evidence to direct crystal form selection and establish control5.

13.
Cureus ; 15(9): e45751, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37872910

RESUMO

In strict accordance with PRISMA 2020 guidelines, our research team conducted a comprehensive systematic literature review (SLR) to explore the treatment and preventive strategies for Sjögren's Syndrome (SS). Leveraging a meticulous search strategy, we scoured reputable databases such as PubMed, PubMed Central, Google Scholar, Web of Science, and The Cochrane Library. Our analysis zeroed in on 10 seminal articles that met our stringent inclusion criteria, providing a holistic view of the existing treatment landscape for SS, along with emerging diagnostic tools and associated biomarkers indicative of lymphoma risk. From a clinical standpoint, our findings unequivocally highlight the detrimental effects of SS on patients' overall well-being. Of particular interest is the growing body of evidence that underscores the effectiveness of natural remedies and over-the-counter supplements rich in antioxidants as viable therapeutic interventions. Contrary to expectations, no single laboratory marker emerged as highly sensitive for the diagnosis of SS. On a promising note, dental implants have been demonstrated to offer lasting benefits with minimal side effects, emphasizing their potential utility in enhancing the oral health of individuals affected by SS. Given the evolving nature of treatment approaches for SS, our review strongly calls for further investigations. Such research endeavors are imperative for validating the effectiveness of these treatment options, whether they serve as primary or preventive care solutions, with the overarching aim of improving the quality of oral health among those suffering from SS.

14.
J Frailty Sarcopenia Falls ; 8(2): 66-73, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37275662

RESUMO

Objectives: Vestibular rehabilitation clinical guidelines document the additional benefit offered by the Mixed Reality environments in the reduction of symptoms and the improvement of balance in peripheral vestibular hypofunction. The HOLOBalance platform offers vestibular rehabilitation exercises, in an Augmented Reality (AR) environment, projecting them using a low- cost Head Mounted Display. The effect of the AR equipment on the performance in three of the commonest vestibular rehabilitation exercises is investigated in this pilot study. Methods: Twenty-five healthy adults (12/25 women) participated, executing the predetermined exercises with or without the use of the AR equipment. Results: Statistically significant difference was obtained only in the frequency of head movements in the yaw plane during the execution of a vestibular adaptation exercise by healthy adults (0.97 Hz; 95% CI=(0.56, 1.39), p<0.001). In terms of difficulty in exercise execution, the use of the equipment led to statistically significant differences at the vestibular-oculomotor adaptation exercise in the pitch plane (OR=3.64, 95% CI (-0.22, 7.50), p=0.049), and in the standing exercise (OR=28.28. 95% CI (23.6, 32.96), p=0.0001). Conclusion: Τhe use of AR equipment in vestibular rehabilitation protocols should be adapted to the clinicians' needs.

15.
Eur Radiol ; 33(11): 8343-8352, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37284866

RESUMO

OBJECTIVES: The diagnosis of osteoid osteomas (OO) about the hip can be challenging as presenting symptoms can mimic other, more common, periarticular pathologies. Our aims were to identify the most common misdiagnoses and treatments, mean delay in diagnosis, characteristic imaging features and provide tips for avoiding diagnostic imaging pitfalls for patients with OO of the hip. METHODS: We identified 33 patients (34 tumors) with OO about the hip who were referred for radiofrequency ablation between 1998 and 2020. Imaging studies reviewed included radiographs (n = 29), CT (n = 34), and MRI (n = 26). RESULTS: The most common initial diagnoses were femoral neck stress fracture (n = 8), femoroacetabular impingement (FAI) (n = 7), and malignant tumor or infection (n = 4). The mean time from symptom onset to diagnosis of OO was 15 months (range, 0.4-84). The mean time from initial incorrect diagnosis to OO diagnosis was 9 months (range, 0-46). CONCLUSIONS: The diagnosis of OO of the hip is challenging, with up to 70% of cases initially misdiagnosed as a femoral neck stress fracture, FAI, bone tumor, or other joint pathology in our series. Consideration of OO in the differential diagnosis of hip pain in adolescent patients and awareness of the characteristic imaging findings are critical for making an accurate diagnosis. KEY POINTS: • The diagnosis of osteoid osteoma of the hip can be challenging, as demonstrated by long delays in time to initial diagnosis and high rates of misdiagnoses which can lead to inappropriate interventions. • Familiarity with the spectrum of imaging features of OO, especially on MRI, is imperative given the increase in the utilization of this modality for the evaluation of young patients with hip pain and FAI. • Consideration of OO in the differential diagnosis of hip pain in adolescent patients and awareness of the characteristic imaging findings, including bone marrow edema and the utility of CT, are critical for making a timely and accurate diagnosis.


Assuntos
Neoplasias Ósseas , Impacto Femoroacetabular , Fraturas do Colo Femoral , Fraturas de Estresse , Osteoma Osteoide , Adolescente , Humanos , Osteoma Osteoide/cirurgia , Neoplasias Ósseas/diagnóstico , Erros de Diagnóstico , Artralgia
16.
Cryst Growth Des ; 23(6): 4638-4654, 2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37304396

RESUMO

The application of computational screening methodologies based on H-bond propensity scores, molecular complementarity, molecular electrostatic potentials, and crystal structure prediction has guided the discovery of novel cocrystals of dapsone and bipyridine (DDS:BIPY). The experimental screen, which included mechanochemical and slurry experiments as well as the contact preparation, resulted in four cocrystals, including the previously known DDS:4,4'-BIPY (2:1, CC44-B) cocrystal. To understand the factors governing the formation of the DDS:2,2'-BIPY polymorphs (1:1, CC22-A and CC22-B) and the two DDS:4,4'-BIPY cocrystal stoichiometries (1:1 and 2:1), different experimental conditions (such as the influence of solvent, grinding/stirring time, etc.) were tested and compared with the virtual screening results. The computationally generated (1:1) crystal energy landscapes had the experimental cocrystals as the lowest energy structures, although distinct cocrystal packings were observed for the similar coformers. H-bonding scores and molecular electrostatic potential maps correctly indicated cocrystallization of DDS and the BIPY isomers, with a higher likelihood for 4,4'-BIPY. The molecular conformation influenced the molecular complementarity results, predicting no cocrystallization for 2,2'-BIPY with DDS. The crystal structures of CC22-A and CC44-A were solved from powder X-ray diffraction data. All four cocrystals were fully characterized by a range of analytical techniques, including powder X-ray diffraction, infrared spectroscopy, hot-stage microscopy, thermogravimetric analysis, and differential scanning calorimetry. The two DDS:2,2'-BIPY polymorphs are enantiotropically related, with form B being the stable polymorph at room temperature (RT) and form A being the higher temperature form. Form B is metastable but kinetically stable at RT. The two DDS:4,4'-BIPY cocrystals are stable at room conditions; however, at higher temperatures, CC44-A transforms to CC44-B. The cocrystal formation enthalpy order, derived from the lattice energies, was calculated as follows: CC44-B > CC44-A > CC22-A.

17.
Virchows Arch ; 483(1): 41-46, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37294448

RESUMO

Osteoid osteomas typically arise in the long bones of extremities. Patients often report pain relieved by NSAIDS, and radiographic findings are often sufficient for diagnosis. However, when involving the hands/feet, these lesions may go unrecognized or misdiagnosed radiographically due to their small size and prominent reactive changes. The clinicopathologic features of this entity involving the hands and feet are not well-described. Our institutional and consultation archives were searched for all cases of pathologically confirmed osteoid osteomas arising in the hands and feet. Clinical data was obtained and recorded. Seventy-one cases (45 males and 26 females, 7 to 64 years; median 23 years) arose in the hands and feet, representing 12% of institutional and 23% of consultation cases. The clinical impression often included neoplastic and inflammatory etiologies. Radiology studies demonstrated a small lytic lesion in all cases (33/33), the majority of which had a tiny focus of central calcification (26/33). Nearly, all cases demonstrated cortical thickening and/or sclerosis and perilesional edema which almost always had an extent two times greater than the size of the nidus. Histologic examination showed circumscribed osteoblastic lesions with formation of variably mineralized woven bone with single layer of osteoblastic rimming. The most common growth pattern of bone was trabecular (n = 34, 48%) followed by combined trabecular and sheet-like (n = 26, 37%) with only 11 (15%) cases presenting with pure sheet-like growth pattern. The majority (n = 57, 80%) showed intra-trabecular vascular stroma. No case showed significant cytology atypia. Follow up was available for 48 cases (1-432 months), and 4 cases recurred. Osteoid osteomas involving the hands and feet follow a similar age and sex distribution as their non-acral counterparts. These lesions often present with a broad differential diagnosis and may initially be confused with chronic osteomyelitis or a reactive process. While the majority of cases have classic morphologic features on histologic exam, a small subset consists solely of sheet-like sclerotic bone. Awareness that this entity may present in the hands and feet will help pathologists, radiologists, and clinicians accurately diagnose these tumors.


Assuntos
Neoplasias Ósseas , Osteoma Osteoide , Masculino , Feminino , Humanos , Osteoma Osteoide/diagnóstico , Osteoma Osteoide/patologia , Neoplasias Ósseas/patologia , Recidiva Local de Neoplasia/diagnóstico , Osso e Ossos , Diagnóstico Diferencial
18.
J Bone Jt Infect ; 8(2): 99-107, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37123500

RESUMO

Objective: confluent T1 hypointense marrow signal is widely accepted to represent osteomyelitis on MRI. Some authors have suggested that non-confluent bone marrow signal abnormality should be considered early osteomyelitis. The purpose of this study was to address this issue by comparing the rate of osteomyelitis and amputation based on T1 marrow signal characteristics. Materials and methods: a total of 112 patients who underwent MRI of the foot for the evaluation of possible osteomyelitis were included. Patients were assigned to confluent T1 hypointense, reticulated T1 hypointense, and normal bone marrow signal groups. Results: patients with confluent T1 hypointense signal on MRI had significantly higher rates of osteomyelitis and amputation at 2 and 14 months post-MRI than the reticulated T1 hypointense group ( p < 0.001 ). Six patients had normal T1 signal, 16.7 % of whom had osteomyelitis and underwent amputation by 2 months post-MRI. Of 61 patients with reticulated T1 hypointense signal, 19.7 % had a diagnosis of osteomyelitis at 2 months post-MRI and 30.8 % had a diagnosis of osteomyelitis at 14 months post-MRI; moreover, 14.8 % and 31.5 % underwent amputation by 2 and 14 months post-MRI, respectively. Of 45 patients with confluent T1 hypointense signal, 73.3 % of patients had osteomyelitis at 2 months post-MRI and 82.5 % had osteomyelitis at 14 months post-MRI. In this group, 66.7 % underwent amputation by 2 months post-MRI and 77.8 % underwent amputation by 14 months post-MRI. Conclusions: over half of the patients with suspected pedal osteomyelitis who had reticulated or normal T1 bone marrow signal on MRI healed with conservative measures. Therefore, we recommend terminology such as "osteitis", "reactive osteitis", or "nonspecific reactive change" to describe bone marrow edema-like signal and reticulated hazy T1 hypointense signal without associated confluent T1 hypointensity. Moreover, we recommend that the MRI diagnosis of osteomyelitis is reserved for confluent T1 hypointense bone signal in the area of concern.

19.
Skeletal Radiol ; 52(9): 1767-1775, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37083978

RESUMO

OBJECTIVE: To examine the multimodality imaging characteristics of parosteal lipomas. MATERIALS AND METHODS: With IRB approval, our institutional imaging database and medical record were retrospectively reviewed from 1990-2020 for cases of pathologically-proven and/or imaging diagnosed parosteal lipomas. RESULTS: There were 22 patients (12 males, 10 females) with a mean age of 57.1 ± 12.7 years (range 31-80 years). 11/22 cases (50%) were pathologically-confirmed on biopsy or surgical resection and 11/22 (50%) had imaging features compatible with parosteal lipoma. Lesions occurred most commonly along the femur (8/22, 36%), followed by the forearm (3/22, 14%). All cases demonstrated a juxtacortical fatty mass containing an osseous excrescence that was firmly attached to the cortical surface. The osseous excrescences were characterized as pedunculated in 16/22 (73%) and sessile in 6/22 (27%). The average largest dimension of the osseus excrescences was 2.4 ± 1.6 cm (range 0.8-6.1 cm) and the lipomatous portions 7.8 ± 3.8 cm (range 2.0-19.5 cm). The excrescences contained mature bone in 12/22 (55%) cases and a mixture of mature bone and radiating bone spicules in 10/22 (45%). There were non-lipomatous elements in the fatty portion of the mass in 13/22 (59%) of cases. Most cases (19/22, 85%) had cortical thickening/periostitis near the base of the osseous stalk. Two patients had a bone scan that demonstrated uptake in the osseous excrescence, and two patients had an FDG PET/CT that demonstrated no uptake. CONCLUSION: Parosteal lipomas are a rare benign lipomatous tumor with pathognomonic multimodality imaging features that may obviate the need for biopsy.


Assuntos
Neoplasias Ósseas , Lipoma , Masculino , Feminino , Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Estudos Retrospectivos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Lipoma/diagnóstico por imagem , Lipoma/patologia , Neoplasias Ósseas/patologia , Tomografia Computadorizada por Raios X , Imageamento por Ressonância Magnética
20.
Cryst Growth Des ; 23(3): 1874-1887, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36879772

RESUMO

The possibility of obtaining cocrystals of kojic acid with organic coformers has been investigated by both computational and experimental approaches. Cocrystallization attempts have been carried out with about 50 coformers, in different stoichiometric ratios, by solution, slurry, and mechanochemical methods. Cocrystals were obtained with 3-hydroxybenzoic acid, imidazole, 4-pyridone, DABCO, and urotropine, while piperazine yielded a salt with the kojiate anion; cocrystallization with theophylline and 4-aminopyridine resulted in stoichiometric crystalline complexes that could not be described with certainty as cocrystals or salts. In the cases of panthenol, nicotinamide, urea, and salicylic acid the eutectic systems with kojic acid were investigated via differential scanning calorimetry. In all other preparations the resulting materials were constituted of a mixture of the reactants. All compounds were investigated by powder X-ray diffraction; the five cocrystals and the salt were fully characterized via single crystal X-ray diffraction. The stability of the cocrystals and the intermolecular interactions in all characterized compounds have been investigated by computational methods based on the electronic structure and pairwise energy calculations, respectively.

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