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1.
Epidemiol Prev ; 48(4-5): 298-308, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39206587

RESUMEN

OBJECTIVES: to document existing geographical inequalities in health in the city of Milan (Lombardy Region, Northern Italy), examining the association between area socioeconomic disadvantage and health outcomes, with the aim to suggest policy action to tackle them. DESIGN: the analysis used an ecological framework; multiple health indicators were considered in the analysis; socioeconomic disadvantage was measured through indicators such as low education, unemployment, immigration status, and housing crowding. For each municipal statistical area, Bayesian Relative Risks of the outcomes (using the Besag-Yorkand-Mollié model) were plotted on the city map. To evaluate the association between social determinants and health outcomes, Spearman correlation coefficients were estimated. SETTING AND PARTICIPANTS: residents in the City of Milan aged between 30 and 75 years who were residing in Milan as of 01.01.2019, grouped in 88 statistical areas. MAIN OUTCOMES MEASURES: all-cause mortality, type-2 diabetes mellitus, hypertension, neoplasms, respiratory diseases, metabolic syndrome, antidepressants use, polypharmacy, and multimorbidity. RESULTS: the results consistently demonstrated a significant association between socioeconomic disadvantage and various health outcomes, with low education exhibiting the strongest correlations. Neoplasms displayed an inverse social gradient, while the relationship with antidepressant use varied. CONCLUSIONS: these findings provide valuable insights into the distribution of health inequalities in Milan and contribute to the existing literature on the social determinants of health. The study highlights the need for targeted interventions to address disparities and promote equitable health outcomes. The results can serve to inform the development of effective public health strategies and policies aimed at reducing health inequalities in the city.


Asunto(s)
Disparidades en el Estado de Salud , Factores Socioeconómicos , Humanos , Italia/epidemiología , Persona de Mediana Edad , Anciano , Adulto , Masculino , Femenino , Determinantes Sociales de la Salud , Teorema de Bayes
2.
J Environ Manage ; 334: 117527, 2023 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-36801798

RESUMEN

Nowadays, the shift toward energy and resource-efficient wastewater treatment plants (WWTPs) has become a necessity rather than a choice. For this purpose, there has been a restored interest in replacing the typical energy and resource-extensive activated sludge process with the two-stage Adsorption/bio-oxidation (A/B) configuration. In the A/B configuration, the role of the A-stage process is to maximize organics diversion to the solids stream and control the following B-stage's influent to allow for the attainment of tangible energy savings. Operating at very short retention times and high loading rates, the influence of the operational conditions on the A-stage process become more tangible than typical activated sludge. Nonetheless, there is very limited understanding of the influence of operational parameters on the A-stage process. Moreover, no studies in the literature have explored the influence of any operational/design parameters on the Alternating Activated Adsorption (AAA) technology which is a novel A-stage variant. Hence, this article mechanistically investigates the independent effect of different operational parameters on the AAA technology. It was inferred that solids retention time (SRT) shall remain below 1 day to allow for energy savings up to 45% and redirecting up to 46% of the influent's COD to the recovery streams. In the meantime, the hydraulic retention time (HRT) can be increased up to 4 h to remove up to 75% of the influent's COD with only 19% decline of the system's COD redirection ability. Moreover, it was observed that the high biomass concentration (above 3000 mg/L) amplified the effect of the sludge poor settleability either due to pin floc settling or high SVI30 which resulted in COD removal below 60%. Meanwhile, the concentration of the extracellular polymeric substances (EPS) was not found to be influenced or to influence process performance. The findings of this study can be employed to formulate an integrative operational approach in which different operational parameters are incorporated to better control the A-stage process and achieve complex objectives.


Asunto(s)
Aguas del Alcantarillado , Eliminación de Residuos Líquidos , Eliminación de Residuos Líquidos/métodos , Carbono , Reactores Biológicos , Adsorción
3.
J Environ Manage ; 303: 114172, 2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-34861502

RESUMEN

The interest in the A-stage of the adsorption/bio-oxidation (A/B) process has considerably increased due to its capacity of carbon redirection to the solids stream. Induced by its flexible and compact design, the Alternating Activated Adsorption (AAA) was recently implemented in full-scale as an alternative A-stage system. However, the literature on such a system is scarce. In this article for the first time, the performance of the novel AAA system is evaluated. Two lab-scale AAA systems were operated as a primary settler replacement (AAA-1) or to complement the primary settler (AAA-2). Systems were assessed in terms of process control, effluent quality and carbon diversion. As settling and aeration are performed in the same reactor, AAA maintained high MLSS (2121 ± 293 mg/L for AAA-1 and 806 ± 116 mg/L for AAA-2) compared to the literature at such a very low aerobic SRT (<6 h). Regardless wastewater strength, AAA attains low oxidation (16-17%) owing to the oxygen supply pattern and short aerobic SRT. Moreover, AAA-1 showed high COD removal efficiency for soluble (67 ± 8%) and particulates (62 ± 14%) as well as COD redirection (47 ± 7%). In addition, it is demonstrated that the simultaneous bottom feeding and top discharging regime adds unique capacity for particulates capture in AAA. On the other hand, low particulates removal and total carbon redirection were observed in the AAA-2. Yet, the overall removal efficiencies are comparable with the literature. It can be concluded that, with further optimizations, AAA system has the potential to outcompete other A-stage systems. As such, sludge settleability is found to be challenging when treating low strength wastewater.


Asunto(s)
Eliminación de Residuos Líquidos , Aguas Residuales , Adsorción , Reactores Biológicos , Carbono , Aguas del Alcantarillado
4.
Aesthet Surg J ; 42(6): 616-625, 2022 05 18.
Artículo en Inglés | MEDLINE | ID: mdl-35029651

RESUMEN

BACKGROUND: Tranexamic acid (TXA) has gained increasing recognition as a valuable pharmacologic agent within plastic surgery. OBJECTIVES: The aim of this study was to investigate the value and safety profile of both intravenous and topically administered TXA in the setting of bilateral reduction mammaplasty. METHODS: A retrospective review was performed to identify consecutive patients who underwent bilateral reduction mammaplasty for symptomatic macromastia (January 2016-July 2021). Pertinent preoperative, intraoperative, and postoperative details were collected/reviewed. Primary outcome measures included hematoma requiring surgical evacuation and clinically significant/symptomatic seroma formation mandating percutaneous aspiration. Patients taking anticoagulation/antiplatelet medication or those with a history of thromboembolic diseases were excluded. Patients who had received TXA were compared to a historical control group who did not receive TXA within the same consecutive cohort. RESULTS: A total of 385 consecutive patients (770 breasts) were included. TXA was used in 514 (66.8%) cases (topical, 318 [61.9%]; intravenous, 170 [33.1%]; intravenous and topical, 26 [5.1%]). Neither seroma nor hematoma were impacted/reduced with TXA (P > 0.05). Increased age (hazards ratio, 1.06 per 1-year increase; 95% CI, 1.004-1.118) significantly increased the risk of hematoma (P = 0.032). The use of drains significantly decreased the risk of seroma (P < 0.0001). Increased BMI increased the risk of seroma (hazards ratio, 1.16 per 1-kg/m2 increase; 95% CI, 1.06-1.26; P = 0.0013). The use of TXA did not impact drain duration. CONCLUSIONS: This study, the largest to date on the use of IV and topical TXA, did not find any reduction in risk when using TXA in breast reduction surgery.


Asunto(s)
Antifibrinolíticos , Mamoplastia , Ácido Tranexámico , Administración Intravenosa , Antifibrinolíticos/efectos adversos , Pérdida de Sangre Quirúrgica/prevención & control , Femenino , Hematoma/etiología , Hematoma/prevención & control , Humanos , Mamoplastia/efectos adversos , Seroma/etiología , Seroma/prevención & control , Ácido Tranexámico/efectos adversos
5.
Comput Econ ; : 1-17, 2022 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-35855727

RESUMEN

In recent time, the two significant events; Coronavirus epidemic and Russian invasion are effecting all over the world in various aspects; healthily, economically, environmentally, and socially, etc. The first event has brought uncertainties to the economic situation in most countries based on the epidemic transmission. In addition to that, on 24th February 2022 the Russian invasion of Ukraine affected negatively almost all stock markets all over the world, but the effects are heterogeneous across countries according to their economic-political relationship or neighbourhood, etc. Due to that, the stock market price in Turkey has been affected dramatically over that period. This empirical study is the first attempts to explore the impact of Coronavirus epidemic and Russian invasion on the stock market index XU100 in Turkey by applying the developed statistical method namely elastic-net regression based on empirical mode decomposition which can precisely tackle the nonstationary and nonlinearity data. Then we performed the robustness check by applying a nonlinear techniques Markov switching regression. The data are collected from the beginning of the epidemic in Turkey from March 11, 2020 until May 31, 2022. The finding reveals that there is significant effect of the Coronavirus spreading on the Turkish stock market index, particularly during the first wave. Then after the Russian Invasion the XU100 index is effected more negatively. As the credit default swap and TL reference interest rate have a negative impact but the foreigner exchange rate has a positive significant impact on the XU100 index, and it varies according to the period of short term and long term. Moreover, the results obtained by using the robustness check shows a robust and consistent finding. In conclusion, understanding the impact of Coronavirus pandemic and Russian invasion on the Turkish stock market can provide important implications for investors, financial sectors, and policymakers.

6.
Eur Arch Otorhinolaryngol ; 278(5): 1505-1513, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33496811

RESUMEN

PURPOSE: Laryngotracheal stenosis describes various airflow compromising conditions leading to laryngeal and tracheal narrowing, including subglottic and tracheal stenosis. Direct laryngobronchoscopy is the diagnostic gold standard for laryngotracheal stenosis. This study aimed to explore the effect of inhaled fluticasone propionate as adjuvant medical therapy in patients with laryngotracheal stenosis after balloon dilation. METHODS: This prospective randomized controlled trial was conducted from April 2019 to April 2020. Fourteen adults (≥ 18 years) with laryngotracheal stenosis consented to participate. All patients underwent endoscopic balloon dilation. Seven patients were treated with inhaled fluticasone propionate, and seven acted as controls. Detailed documentation of operative findings and pre- and post-balloon dilation spirometry measurements were recorded. Basic demographic data and operative details, including information about the percentage of laryngotracheal stenosis, distance of laryngotracheal stenosis from the vocal cords, the stenotic segment vertical length, and the largest endotracheal tube used before and after dilation were noted. RESULTS: Spirometry measurements were obtained on 34 occasions (17 before and 17 after balloon dilation). The two groups were similar in spirometry values after treatment. Both groups had significantly improved on most spirometry values after balloon dilation. CONCLUSION: We found that using inhaled steroids after balloon dilatation in patients with laryngotracheal stenosis had no benefit over non-user patients in spirometry parameters during the short postoperative follow-up. To confirm this outcome, we recommend a large-scale double-blind study with a longer follow-up period.


Asunto(s)
Laringoestenosis , Estenosis Traqueal , Adulto , Constricción Patológica , Dilatación , Fluticasona , Humanos , Laringoestenosis/etiología , Laringoestenosis/terapia , Estudios Prospectivos , Estenosis Traqueal/etiología , Estenosis Traqueal/terapia , Resultado del Tratamiento
7.
Ann Plast Surg ; 87(5): e86-e91, 2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-33833170

RESUMEN

BACKGROUND: Nipple-areolar complex (NAC) tattooing remains a simple and safe procedure, which complements breast reconstruction. This study reviews 11 years of NAC tattooing to identify risk factors for tattoo-related complications. METHODS: Patients undergoing NAC tattooing from January 2009 to March 2020 were reviewed. Patient information, reconstructive, and tattoo procedural details were analyzed. Tattoo-related breast infections, defined as breast redness requiring antibiotic therapy within 30 days after tattoo, were captured. Patients with reactive breast redness during the first 2 postprocedural days were excluded. RESULTS: Overall, 539 patients (949 breasts) were included. Implant-based reconstruction (IBR) was performed in 73.6% of breasts (n = 698), whereas 26.4% (n = 251) underwent autologous-based reconstruction (ABR). Acellular-dermal matrix was used in 547 breasts (57.6%). There as a 13.7% (n = 130) of breasts that underwent pretattoo radiation. There was a 65.3% (n = 456) of breasts that underwent subpectoral IBR, whereas 34.7% (n = 242) breasts underwent prepectoral IBR. Tattoo-related infection rate was 2.2% (n = 21 breasts). Mean time to infection was 6.5 ± 5.3 days. There was a 85.7% (n = 18) of infections that occurred in IBR patients, one third occurring in radiated patients. There was a 95.2% (n = 20) of infections that were treated with oral antibiotics only. One explantation was performed after failed intravenous antibiotics. On multivariable analysis, radiation history (odds ratio, 4.1, P = 0.007) and prepectoral IBR (odds ratio, 2.8, P = 0.036) were independent predictors of tattoo-related infection. Among irradiated breasts, breasts with IBR had greater odds of developing tattoo-related infection versus breasts with ABR (P = 0.025). CONCLUSIONS: Although tattoo-related infections were uncommon, previous radiation and prepectoral IBR were both found to be independent predictors of tattoo-related breast infection. There is a role for preprocedural prophylactic antibiotics in these patients to mitigate infectious risk.


Asunto(s)
Neoplasias de la Mama , Mamoplastia , Tatuaje , Femenino , Humanos , Mamoplastia/efectos adversos , Pezones/cirugía , Estudios Retrospectivos , Factores de Riesgo , Tatuaje/efectos adversos
8.
J Environ Manage ; 290: 112543, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33887639

RESUMEN

Within wastewater treatment plants (WWTPs), the anaerobically produced biogas is often underutilized. Fortunately, methanotrophic based biotechnologies can be the remedy for on-site exploitation and recovery of unused biogas. In this regard, efforts have been placed on evaluating the suitably of methanotrophs to be deployed in WWTPs. Even so, the effect of chemical oxygen demand (COD) on methanotrophic activity and methanotrophic sludge digestibility have not been studied, which is the focus of the present study. A methanotrophic culture enriched from activated sludge was exposed to four different COD concentrations (0-540 mg/L) to evaluate the effect of COD on the culture activity in batch mode. It was attained that the presence of COD concentrations up to 540 mg/L has limited influence on methanotrophic activity. This finding was supported by the similar average methane uptake rate (between 2.48 and 2.53 mgCH4/hr) and consumption (61.4 ± 1.5%) observed under the different COD concentrations. On the other hand, methanotrophic sludge was digested in comparison to waste activated sludge (WAS) collected from a WWTP for more than 40 days to evaluate its digestibility. It was obtained that the methanotrophic sludge had a methane specific yield of approximately 1.72 times greater than WAS and had a higher solids destruction rate. This research is another step demonstrating the feasibility of methanotrophs integration in WWTP.


Asunto(s)
Aguas del Alcantarillado , Eliminación de Residuos Líquidos , Anaerobiosis , Análisis de la Demanda Biológica de Oxígeno , Reactores Biológicos , Metano
9.
Small ; 16(6): e1903897, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31961995

RESUMEN

There is a crucial need for effective and easily dispersible colloidal microsensors able to detect local pH changes before irreversible damages caused by demineralization, corrosion, or biofilms occur. One class of such microsensors is based on molecular dyes encapsulated or dispersed either in polymer matrices or in liquid systems exhibiting different colors upon pH variations. They are efficient but often rely on sophisticated and costly syntheses, and present significant risks of leakage and photobleaching damages, which is detrimental for mainstream applications. Another approach consists of exploiting the distance-dependent plasmonic properties of metallic nanoparticles. Still, assembling nanoparticles into dispersible colloidal pH-sensitive sensors remains a challenge. Here, it is shown how to combine optically active plasmonic gold nanoparticles and pH-responsive thin shells into "plasmocapsules." Upon pH change, plasmocapsules swell or shrink. Concomitantly, the distance between the gold nanoparticles embedded in the polymeric matrix varies, resulting in an unambiguous color change. Billions of micron-size sensors can thus be easily fabricated. They are nonintrusive, reusable, and sense local pH changes. Each plasmocapsule is an independent reversible microsensor over a large pH range. Finally, their potential use for the detection of bacterial growth is demonstrated, thus proving that plasmocapsules are a new class of sensing materials.


Asunto(s)
Colorimetría , Oro , Nanopartículas del Metal , Colorimetría/instrumentación , Colorimetría/métodos , Concentración de Iones de Hidrógeno , Nanopartículas del Metal/química
10.
World J Surg ; 44(8): 2518-2525, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32314007

RESUMEN

BACKGROUND: The pediatric resuscitation and trauma outcome (PRESTO) model was developed to aid comparisons of risk-adjusted mortality after injury in low- and middle-income countries (LMICs). We sought to validate PRESTO using data from a middle-income country (MIC) trauma registry and compare its performance to the Pediatric Trauma Score (PTS), Revised Trauma Score, and pediatric age-adjusted shock index (SIPA). METHODS: We included children (age < 15 years) admitted to a single trauma center in South Africa from December 2012 to January 2019. We excluded patients missing variables necessary for the PRESTO model-age, systolic blood pressure, pulse, oxygen saturation, neurologic status, and airway support. Trauma scores were assigned retrospectively. PRESTO's previously high-income country (HIC)-validated optimal threshold was compared to MIC-validated threshold using area under the receiver operating characteristic curves (AUROC). Prediction of in-hospital death using trauma scoring systems was compared using ROC analysis. RESULTS: Of 1160 injured children, 988 (85%) had complete data for calculation of PRESTO. Median age was 7 (IQR: 4, 11), and 67% were male. Mortality was 2% (n = 23). Mean predicted mortality was 0.5% (range 0-25.7%, AUROC 0.93). Using the HIC-validated threshold, PRESTO had a sensitivity of 26.1% and a specificity of 99.7%. The MIC threshold showed a sensitivity of 82.6% and specificity of 89.4%. The MIC threshold yielded superior discrimination (AUROC 0.86 [CI 0.78, 0.94]) compared to the previously established HIC threshold (0.63 [CI 0.54, 0.72], p < 0.0001). PRESTO showed superior prediction of in-hospital death compared to PTS and SIPA (all p < 0.01). CONCLUSION: PRESTO can be applied in MIC settings and discriminates between children at risk for in-hospital death following trauma. Further research should clarify optimal decision thresholds for quality improvement and benchmarking in LMIC settings.


Asunto(s)
Medicina de Emergencia/normas , Resucitación/normas , Centros Traumatológicos/normas , Heridas y Lesiones/terapia , Adolescente , Algoritmos , Área Bajo la Curva , Presión Sanguínea , Niño , Preescolar , Femenino , Frecuencia Cardíaca , Mortalidad Hospitalaria , Hospitalización , Humanos , Renta , Lactante , Recién Nacido , Masculino , Mejoramiento de la Calidad , Curva ROC , Sistema de Registros , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Choque/terapia , Sudáfrica
12.
Environ Sci Technol ; 52(21): 12376-12387, 2018 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-30339372

RESUMEN

The fundamental components required for scaling up the production of biogas-based biopolymers can be provided through a single process, that is, anaerobic digestion (AD). In this research, the possibility of enriching methane-utilizing mixed cultures from the AD process was explored as well as their capability to accumulate polyhydroxyalkanoates (PHAs). For almost 70 days of operation in a fed-batch cyclic mode, the specific growth rate was 0.078 ± 0.005 h-1 and the biomass yield was 0.7 ± 0.08 mg-VSS/mg-CH4. Adjusting the nitrogen levels in AD centrate resulted in results comparable to those obtained with a synthetic medium. The enriched culture could accumulate up to 51 ± 2% PHB. On the other hand, when the culturing medium was supplemented with valeric acid, the enriched bacteria were able to produce polyhydroxybutyrate- co-valerate (PHBV) up to 52 ± 6% with an HV percentage of 33 ± 5%. Increasing the valeric acid concentration in the culturing medium above 100 mg/L decreased the overall amount of PHBV by 60%, whereas the number of HV units incorporated was not affected. Changing the methane-to-oxygen ratio (M/O) from 1:1 to 4:1 caused an almost 80% decline in PHB accumulation. In addition, M/O had a significant effect on the fraction composition of PHBV at different valeric acid concentrations.


Asunto(s)
Polihidroxialcanoatos , Anaerobiosis , Reactores Biológicos , Metano , Nitrógeno , Aguas del Alcantarillado
13.
J Environ Sci (China) ; 70: 87-96, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30037414

RESUMEN

Methanotrophic based process can be the remedy to offset the wastewater treatment facilities increasing energy requirements due to methanotroph's unique ability to integrate methane assimilation with multiple biotechnological applications like biological nitrogen removal and methanol production. Regardless of the methanotrophic process end product, the challenge to maintain stable microbial growth in the methanotrophs cultivation bioreactor at higher cell densities is one of the major obstacles facing the process upscaling. Therefore, a series of consecutive batch tests were performed to attentively investigate the biomass density influence on type I methanotrophs bacterial growth. In addition, food to microorganisms (F/M), carbon to nitrogen (C/N) and nitrogen to microorganisms (N/M) ratio effect on the microbial activity was studied for the first time. It was clarified that the F/M ratio is the most influencing factor on the microbial growth at higher biomass densities rather than the biomass density increase, whereas C/N and N/M ratio change, while using nitrate as the nitrogen source, does not influence methanotrophs microbial growth. These study results would facilitate the scaling up of methanotrophic based biotechnology by identifying that F/M ratio as the key parameter that influences methanotrophs cultivation at high biomass densities.


Asunto(s)
Reactores Biológicos/microbiología , Aguas del Alcantarillado/microbiología , Eliminación de Residuos Líquidos/métodos , Metano/metabolismo , Aguas Residuales/microbiología
14.
Small ; 13(39)2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28834168

RESUMEN

Efficiently detecting mechanical deformations within materials is critical in a wide range of devices, from micro-electromechanical systems to larger structures in the aerospace industry. This communication reports the fabrication of new mechanochromic micrometer-size capsules enabling the detection of strains. These microcapsules are synthesized using an emulsification approach. They are made of densely packed gold nanoparticles embedded in a spherical silica crust. Billions of these composite spherical microcapsules are fabricated in a single batch. Each microcapsule is an opto-mechanosensor by itself, and can easily be recovered and incorporated into polymer films. When the films are stretched, the microcapsules are deformed into elongated ellipsoidal shapes and the distance between the Au NPs embedded in their shells concomitantly increases. As the extinction of Au NPs depends on the separation between the Au NPs, microcapsules exhibit different colors when they are elongated. These novel sensitive microcapsules can be used to detect and measure strain in polymer films by outputting color information.

15.
Nat Mater ; 14(1): 101-8, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25218059

RESUMEN

The microscopic kinetics of ubiquitous solid-solid phase transitions remain poorly understood. Here, by using single-particle-resolution video microscopy of colloidal films of diameter-tunable microspheres, we show that transitions between square and triangular lattices occur via a two-step diffusive nucleation pathway involving liquid nuclei. The nucleation pathway is favoured over the direct one-step nucleation because the energy of the solid/liquid interface is lower than that between solid phases. We also observed that nucleation precursors are particle-swapping loops rather than newly generated structural defects, and that coherent and incoherent facets of the evolving nuclei exhibit different energies and growth rates that can markedly alter the nucleation kinetics. Our findings suggest that an intermediate liquid should exist in the nucleation processes of solid-solid transitions of most metals and alloys, and provide guidance for better control of the kinetics of the transition and for future refinements of solid-solid transition theory.

16.
Soft Matter ; 11(46): 9020-5, 2015 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-26412312

RESUMEN

Clusters of fast and slow correlated particles, identified as dynamical heterogeneities (DHs), constitute a central aspect of glassy dynamics. A key factor of the glass transition scenario is a significant increase of the cluster size ξ4 as the transition is approached. In need of easy-to-compute tools to measure ξ4, the dynamical susceptibility χ4 was introduced recently, and used in various experimental studies to probe DHs. Here, we investigate DHs in dense microgel suspensions using image correlation analysis, and compute both χ4 and the four-point correlation function G4. The spatial decrease of G4 provides a direct access to ξ4, which is found to grow significantly with increasing volume fraction. However, this increase is not captured by χ4. We show that the assumptions that validate the connection between χ4 and ξ4 are not fulfilled in our experiments.

17.
Nature ; 459(7244): 230-3, 2009 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-19444211

RESUMEN

When the packing fraction is increased sufficiently, loose particulates jam to form a rigid solid in which the constituents are no longer free to move. In typical granular materials and foams, the thermal energy is too small to produce structural rearrangements. In this zero-temperature (T = 0) limit, multiple diverging and vanishing length scales characterize the approach to a sharp jamming transition. However, because thermal motion becomes relevant when the particles are small enough, it is imperative to understand how these length scales evolve as the temperature is increased. Here we used both colloidal experiments and computer simulations to progress beyond the zero-temperature limit to track one of the key parameters-the overlap distance between neighbouring particles-which vanishes at the T = 0 jamming transition. We find that this structural feature retains a vestige of its T = 0 behaviour and evolves in an unusual manner, which has masked its appearance until now. It is evident as a function of packing fraction at fixed temperature, but not as a function of temperature at fixed packing fraction or pressure. Our results conclusively demonstrate that length scales associated with the T = 0 jamming transition persist in thermal systems, not only in simulations but also in laboratory experiments.

18.
Nature ; 456(7224): 898-903, 2008 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-19092926

RESUMEN

Geometric frustration arises when lattice structure prevents simultaneous minimization of local interaction energies. It leads to highly degenerate ground states and, subsequently, to complex phases of matter, such as water ice, spin ice, and frustrated magnetic materials. Here we report a simple geometrically frustrated system composed of closely packed colloidal spheres confined between parallel walls. Diameter-tunable microgel spheres are self-assembled into a buckled triangular lattice with either up or down displacements, analogous to an antiferromagnetic Ising model on a triangular lattice. Experiment and theory reveal single-particle dynamics governed by in-plane lattice distortions that partially relieve frustration and produce ground states with zigzagging stripes and subextensive entropy, rather than the more random configurations and extensive entropy of the antiferromagnetic Ising model. This tunable soft-matter system provides a means to directly visualize the dynamics of frustration, thermal excitations and defects.

19.
Plast Reconstr Surg Glob Open ; 12(6): e5860, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38872991

RESUMEN

Hidradenitis suppurativa (HS) is a chronic, relapsing inflammatory disease of the skin, characterized by recurrent draining sinuses and abscesses, predominantly in skin folds carrying terminal hairs and apocrine glands. Treatment for this debilitating disease has been medical management with antibiotics and immune modulators. With the advent of better reconstructive surgical techniques, the role of surgery in the treatment of HS has expanded, from being a last resort to a modality that is deployed earlier. Larger defects can be more easily reconstructed, allowing for a more radical excision of diseased areas. Locoregional flaps, perforator flaps, and propeller flaps that use the fasciocutaneous tissue allow reconstruction of defects with similar tissue, and provide better cosmetic and functional outcomes. They are easy to execute and can be performed even in resource-poor settings with concurrent use of immune modulators and postoperative antibiotics. Hidradenitis can be successfully treated with surgery in early stages as well as severe disease, due to the advances in understanding disease behavior, multidisciplinary care, and advanced reconstructive techniques. Coupled with a multidisciplinary care team, surgery offers a durable, lasting cure for HS, significantly reducing disease morbidity.

20.
Clin Case Rep ; 12(6): e8984, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38845797

RESUMEN

Bronchopulmonary sequestration, a rare congenital anomaly, involves a nonfunctioning lung tissue mass supplied by anomalous vessels. It is rarely infected by Actinomyces, further complicating the clinical presentation, with limited reported cases. This case highlights the distinctive clinical aspects, diagnostic challenges, and successful management strategies of such a rare clinical entity.

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