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1.
Chem Rev ; 124(1): 1-26, 2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38118062

RESUMEN

From the stability of colloidal suspensions to the charging of electrodes, electric double layers play a pivotal role in aqueous systems. The interactions between interfaces, water molecules, ions and other solutes making up the electrical double layer span length scales from Ångströms to micrometers and are notoriously complex. Therefore, explaining experimental observations in terms of the double layer's molecular structure has been a long-standing challenge in physical chemistry, yet recent advances in simulations techniques and computational power have led to tremendous progress. In particular, the past decades have seen the development of a multiscale theoretical framework based on the combination of quantum density functional theory, force-field based simulations and continuum theory. In this Review, we discuss these theoretical developments and make quantitative comparisons to experimental results from, among other techniques, sum-frequency generation, atomic-force microscopy, and electrokinetics. Starting from the vapor/water interface, we treat a range of qualitatively different types of surfaces, varying from soft to solid, from hydrophilic to hydrophobic, and from charged to uncharged.

2.
Microsurgery ; 44(2): e31136, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38342995

RESUMEN

INTRODUCTION: Above elbow transplants represent 19% of the upper extremity transplants. Previous large-animal models have been too distal or heterotopic, did not use immunosuppression and had short survival. We hypothesize that an orthotopic forelimb transplant model, under standard immunosuppression, is feasible and can be used to address questions on peri-transplant ischemia reperfusion injury, and post-transplantation vascular, immunologic, infectious, and functional outcomes. MATERIALS AND METHODS: Four forelimbs were used for anatomical studies. Four mock transplants were performed to establish technique/level of muscle/tendon repairs. Four donor and four recipient female Yucatan minipigs were utilized for in-vivo transplants (endpoint 90-days). Forelimbs were amputated at the midarm and preserved through ex vivo normothermic perfusion (EVNP) utilizing an RBC-based perfusate. Hourly perfusate fluid-dynamics, gases, electrolytes were recorded. Contractility during EVNLP was graded hourly using the Medical Research Council scale. EVNP termination criteria included systolic arterial pressure ≥115 mmHg, compartment pressure ≥30 mmHg (at EVNP endpoint), oxygen saturation reduction of 20%, and weight change ≥2%. Indocyanine green (ICG) angiography was performed after revascularization. Limb rejection was evaluated clinically (rash, edema, temperature), and histologically (BANFF classification) collecting per cause and protocol biopsies (POD 1, 7, 30, 60 and endpoint). Systemic infections were assessed by blood culture and tissue histology. CT scan was used to confirm bone bridging at endpoint. RESULTS: Animals 2, 4 reached endpoint with grade 0-I rejection. Limbs 1, 3 presented grade III rejection on days 6, 61. CsA troughs averaged 461 ± 189 ng/mL. EVNLP averaged 4.3 ± 0.52 h. Perfusate lactate, PO2 , and pH were 5.6 ± 0.9 mmol/L, 557 ± 72 mmHg and 7.5 ± 0.1, respectively. Muscle contractions were 4 [1] during EVNLP. Transplants 2, 3, 4 showed bone bridging on CT. CONCLUSION: We present preliminary evidence supporting the feasibility of an orthotopic, mid-humeral forelimb allotransplantation model under standard immunosuppression regimen. Further research should validate the immunological, infectious, and functional outcomes of this model.


Asunto(s)
Miembro Anterior , Extremidad Superior , Porcinos , Animales , Femenino , Porcinos Enanos , Miembro Anterior/cirugía , Miembro Anterior/irrigación sanguínea , Modelos Animales , Contracción Muscular
3.
J Biochem Mol Toxicol ; 37(5): e23325, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36843533

RESUMEN

We evaluated the activity of core-shell ZnO nanoparticles (ZnO-NPs@polymer shell) containing Oxaliplatin via polymerization through in vitro studies and in vivo mouse models of colorectal cancer. ZnO NPs were synthesized in situ when the polymerization step was completed by co-precipitation. Gadolinium coordinated-ZnONPs@polymer shell (ZnO-Gd NPs@polymer shell) was synthesized by exploiting Gd's oxophilicity (III). The biophysical properties of the NPs were studied using powder X-ray diffraction (PXRD), Fourier transforms infrared spectroscopy, Ultraviolet-visible spectroscopy (UV-Vis), field emission electron microscopy (FESEM), transmission electron microscopy (TEM), atomic force microscopy, dynamic light scattering, and z-potential. (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) was used to determine the antiproliferative activity of ZnO-Gd-OXA. Moreover, a xenograft mouse model of colon cancer was exerted to survey its antitumor activity and effect on tumor growth. In the following, the model was also evaluated by histological staining (H-E; Hematoxylin & Eosin and trichrome staining) and gene expression analyses through the application of RT-PCR/ELISA, which included biochemical evaluation (MDA, thiols, SOD, CAT). The formation of ZnO NPs, which contained a crystallite size of 16.8 nm, was confirmed by the outcomes of the PXRD analysis. The Plate-like morphology and presence of Pt were obtained in EDX outcomes. TEM analysis displayed the attained ZnO NPs in a spherical shape and a diameter of 33 ± 8.5 nm, while the hydrodynamic sizes indicated that the particles were highly aggregated. The biological results demonstrated that ZnO-Gd-OXA inhibited tumor growth by inducing reactive oxygen species and inhibiting fibrosis, warranting further research on this novel colorectal cancer treatment agent.


Asunto(s)
Neoplasias del Colon , Nanopartículas , Óxido de Zinc , Humanos , Ratones , Animales , Oxaliplatino/farmacología , Óxido de Zinc/farmacología , Óxido de Zinc/química , Nanopartículas/química , Extractos Vegetales/química
4.
Curr Opin Colloid Interface Sci ; 55: 101471, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34093064

RESUMEN

Airborne transmission is considered as an important route for the spread of infectious diseases, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and is primarily determined by the droplet sedimentation time, that is, the time droplets spend in air before reaching the ground. Evaporation increases the sedimentation time by reducing the droplet mass. In fact, small droplets can, depending on their solute content, almost completely evaporate during their descent to the ground and remain airborne as so-called droplet nuclei for a long time. Considering that viruses possibly remain infectious in aerosols for hours, droplet nuclei formation can substantially increase the infectious viral air load. Accordingly, the physical-chemical factors that control droplet evaporation and sedimentation times and play important roles in determining the infection risk from airborne respiratory droplets are reviewed in this article.

5.
J Surg Res ; 268: 354-362, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34403855

RESUMEN

BACKGROUND: Histomorphometry quantitatively evaluates nerve regeneration. Total myelinated fiber count (TMFC) is most accurately obtained manually across full nerve cross-sections, but most researchers opt for automated, sampled analysis. Few of the numerous techniques available have been validated. The goal of this study was to compare common histomorphometric methods (full manual [FM], sampled manual [SM], and sampled automatic [SA]) to determine their reliability and consistency. MATERIAL AND METHODS: Twenty-four rats underwent sciatic nerve (SN) repair with 20mm isografts; SNs distal to the graft were analyzed. TMFC was manually determined in each full cross-section. Counts were also extrapolated from sampled fields, both manually and automatically with ImageJ software. Myelinated fiber diameter, axon diameter, and myelin sheath thickness were measured manually in full and sampled fields; G-ratio was calculated. Repeated-measures MANOVA, Spearman correlation, and Wilcoxon signed-rank tests were performed. A systematic review of histomorphometry in rat SN repair was performed to analyze the variability of techniques in the literature. RESULTS: FM TMFC was 13,506 ± 4,217. Both sampled methods yielded significantly different TMFCs (SM:14.4 ± 13.4%, P< 0.001; SA:21.8 ± 44.7%, P = 0.037). All three methods strongly correlated with each other, especially FM and SM (rs = 0.912, P< 0.001). FM fiber diameter, axon diameter, and myelin sheath thickness did not differ from SM (P = 0.493, 0.209, and 0.331, respectively). 65% of papers used sampling; 78% utilized automated or semi-automated analysis. Software, sampling, and histomorphometric parameters varied widely. CONCLUSION: SM and SA analysis are reliable with standardized, systematic sampling. Transparency is essential to allow comparison of data; meanwhile, researchers must be cognizant of the wide variety of methodologies in the literature.


Asunto(s)
Axones , Regeneración Nerviosa , Animales , Axones/fisiología , Vaina de Mielina/fisiología , Ratas , Reproducibilidad de los Resultados , Nervio Ciático/cirugía
6.
Microsurgery ; 41(3): 286-295, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33511636

RESUMEN

INTRODUCTION: Rat sciatic nerve injury (PNR) is the most utilized model in studies on peripheral nerve regeneration. However, large animal models are increasingly favored based on the assumption that nerve regeneration in rodents achieves more favorable outcomes than in humans. The purpose of this meta-analysis was to investigate which rat PNR models are more stringent and should be used before utilizing large animal experimentation. METHODS: A PRISMA-guided meta-analysis of the English literature regarding functional outcomes in rat peripheral nerve injury models was conducted. Outcomes of five basic scenarios: (1) transected nerve/negative control, (2) transection with primary microsurgical repair, (3) isogenic/autologous grafts, (4) acellular-allogenic grafts, and (5) limb transplantation were compared to sciatic nerves without any intervention/positive control. Outcomes were compared using Sciatic Functional Index (SFI). Log-based projections were generated and evaluated using mean squared error (MSE), one-way-ANOVA, and Tukey-HSD post-hoc analysis. RESULTS: In total, 167 articles met the inclusion criteria. The earliest manifestations of motor recovery were encountered in the transection and primary repair group (p <.0005). There was a significant difference in recovery time and degree of recovery between all surgical models (p <.0005). At 24 weeks, the SFI in hindlimb transplantation group was significantly worse than all other groups (-74.07 ± 2.74, p <.0005). Autografts smaller than 10 mm recovered sooner than autografts longer than 10 mm (p = .021) and autografts recovered faster than allografts. CONCLUSION: This meta-analysis does not support the belief that neuro-regeneration is exceptional in transection models. These models remain adequate to provide translatable information and should initially be used in investigational studies.


Asunto(s)
Traumatismos de los Nervios Periféricos , Animales , Autoinjertos , Miembro Posterior , Regeneración Nerviosa , Ratas , Recuperación de la Función , Nervio Ciático
7.
Mol Biol Rep ; 47(2): 867-875, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31873873

RESUMEN

Metabolic syndrome (MetS) is associated with a pro-inflammatory state and endothelial dysfunction that places subjects with MetS at a higher risk of atherosclerosis. Inflammatory biomarkers are raised in patients at risk of developing cardiovascular diseases. In the current study, we aimed to examine the possible association between MetS and serum soluble adhesion molecules, hs-CRP, uric acid, and the genetic variations related to vascular endothelial growth factor (VEGF) gene. In this cross-sectional study, participants were enrolled from the Mashhad stroke and heart atherosclerotic disorders (MASHAD) study. The International Diabetes Federation criteria were used to define the MetS. Cell adhesion molecules (CAM) and serum hs-CRP were measured by ELISA and PEG-enhanced immunoturbidimetry method, respectively. We used a logistic regression analysis to determine independent associations of CAMs with the VEGF polymorphisms and MetS. Two hundred and 59 participants with and without MetS were enrolled. Participants with MetS and DM had a significantly higher serum E-selectin level (p < 0.05). Participants with a high serum E-selectin level had higher levels of hs-CRP, FBG, TG, uric acid, BMI and lower levels of serum HDL-C (p < 0.05). Interestingly, individuals with MetS with a genetic variant of the VEGF gene (rs6921438) had higher level of serum ICAM-1 (p = 0.04). There were significant associations between serum E-selectin concentrations and the presence of MetS, and its risk factors. Moreover, we demonstrated that MetS subjects with the rs6921438 genetic variant had a higher serum level of ICAM-1 (p < 0.05).


Asunto(s)
Moléculas de Adhesión Celular/genética , Síndrome Metabólico/genética , Síndrome Metabólico/metabolismo , Adulto , Biomarcadores/sangre , Proteína C-Reactiva/análisis , Moléculas de Adhesión Celular/análisis , Moléculas de Adhesión Celular/sangre , Colesterol/análisis , Colesterol/sangre , Estudios Transversales , Diabetes Mellitus/sangre , Selectina E/sangre , Selectina E/genética , Femenino , Humanos , Molécula 1 de Adhesión Intercelular/sangre , Molécula 1 de Adhesión Intercelular/genética , Masculino , Síndrome Metabólico/sangre , Persona de Mediana Edad , Factores de Riesgo , Triglicéridos/sangre , Ácido Úrico/análisis , Ácido Úrico/sangre , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo
8.
Phys Chem Chem Phys ; 20(48): 30365-30375, 2018 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-30489580

RESUMEN

The electroosmosis effects at the interface of an aqueous NaCl solution and a charged silicon surface are studied using a molecular dynamics (MD) method. Considering a plug-like electroosmotic flow, we identified a thin interfacial layer in the immediate vicinity of the charged surface, where the flow velocity experiences almost linear spatial variations. The thickness of this interfacial layer is found to be linearly dependent on the surface charge density, with a negative slope which slightly depends on the surface hydrophobicity while being independent of the salt concentration, electric field strength, and orientation of the surface lattice. It is also found that upon increasing the surface charge density, the effective slip length first increases up to a maximum amount and then follows an almost linear reduction. We found that increasing the salt concentration drastically reduces the surface charge at which the effective slip length reaches its maximum amount. For highly concentrated solutions, therefore, the effective slip length could be assumed to change linearly in the whole range of the surface charge density, with a slope which is proportional to the square root of the electric field strength divided by the depth of the potential well assigned to the surface atoms εwall. Also, in a wide range of the surface charge density, the slip velocity is found to be a constant fraction of the electroosmotic velocity, which could be measured experimentally. Finally, by comparing the electroosmotic velocities calculated from the Stokes equation (considering both the slip and no-slip boundary conditions) with our MD results, we found that the no-slip boundary condition, which is normally used in analytical calculations, leads to a very inaccurate result for the studied system.

9.
Phys Chem Chem Phys ; 20(35): 22517-22524, 2018 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-30140803

RESUMEN

We study the ion density, shear viscosity and electroosmotic mobility of an aqueous monovalent electrolyte at a charged solid surface using molecular dynamics simulations. Upon increasing the surface charge density, ions are displaced first from the diffuse layer to the outer Helmholtz layer, increasing its viscosity, and subsequently to the hydrodynamically stagnant inner Helmholtz layer. The ion redistribution causes both charge inversion and reversal of the electroosmotic mobility. Because of the surface-charge dependent interfacial hydrodynamic properties, however, the charge density of mobility reversal differs from the charge density of charge inversion, depending on the salt concentration and the chemical details of the ions and the surface. Mobility reversal cannot be described by an effective slip boundary condition alone - the spatial dependence of the viscosity is essential.

10.
J Craniofac Surg ; 29(6): e543-e548, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29554073

RESUMEN

Calcium phosphate bioceramics has recently experienced increased interest in bone reconstruction. Mimicking of natural structure of bone, like the use of nanomaterials, is an attractive approach for generating scaffolds for bone regeneration. The aim of present study was to evaluate the effect of nanonization on the biphasic calcium phosphate (BCP) ceramic in the repair of bone cavities in the canine mandible. A commercial BCP was dry-milled in a high energy planetary ball mill with zirconia balls and container. Three holes (8 mm in diameter) were outlined to the depth of cortical bone of mandibular angle of 5 dogs bilaterally. The first hole (positive control group A, n = 10) was filled in with commercial BCP material. The second hole was loaded with the nanonized BCP (experimental group C, n = 10) and the third one was left untreated (negative control group B, n = 10). The defects were allowed to regenerate for 8 weeks. New bone formation was greater in groups A and C than in B. No difference was seen between group A and group C (P = 0.676). The residual bone material in group C (19.34 ±â€Š8.03) was as much as one-half of that in group A (38.69 ±â€Š7.90%) (P = 0.000). The negative control group B presented the highest amount of soft tissue within the bone defects. The least percentage of marrow space was found in the positive control group (13.23 ±â€Š13.52). Our results depicted that the rate of resorption increased significantly after nanonization even though the nano-sized BCP failed to make a superior regeneration than the ordinary BCP.


Asunto(s)
Regeneración Ósea/efectos de los fármacos , Hidroxiapatitas/farmacología , Mandíbula/cirugía , Reconstrucción Mandibular/métodos , Animales , Cerámica , Perros , Modelos Animales
11.
J Chem Phys ; 147(20): 204701, 2017 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-29195292

RESUMEN

Investigation of the effects of E-fields on the liquid-vapor interface is essential for the study of floating water bridge and wetting phenomena. The present study employs the molecular dynamics method to investigate the effects of parallel and perpendicular E-fields on the water liquid-vapor interface. For this purpose, density distribution, number of hydrogen bonds, molecular orientation, and surface tension are examined to gain a better understanding of the interface structure. Results indicate enhancements in parallel E-field decrease the interface width and number of hydrogen bonds, while the opposite holds true in the case of perpendicular E-fields. Moreover, perpendicular fields disturb the water structure at the interface. Given that water molecules tend to be parallel to the interface plane, it is observed that perpendicular E-fields fail to realign water molecules in the field direction while the parallel ones easily do so. It is also shown that surface tension rises with increasing strength of parallel E-fields, while it reduces in the case of perpendicular E-fields. Enhancement of surface tension in the parallel field direction demonstrates how the floating water bridge forms between the beakers. Finally, it is found that application of external E-fields to the liquid-vapor interface does not lead to uniform changes in surface tension and that the liquid-vapor interfacial tension term in Young's equation should be calculated near the triple-line of the droplet. This is attributed to the multi-directional nature of the droplet surface, indicating that no constant value can be assigned to a droplet's surface tension in the presence of large electric fields.

12.
Am J Orthod Dentofacial Orthop ; 150(3): 436-43, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27585771

RESUMEN

INTRODUCTION: The use of miniscrews as anchorage has become increasingly popular, but there is no consensus on the best insertion angle. The purpose of this study was to determine the impact of insertion angle on implant primary stability. METHODS: Sixty-four miniscrews, 6 × 1.6 mm, were placed in 64 fresh bone segments from 32 sheep mandibles. The miniscrews were inserted into the bone surface at 4 angles: 30°, 45°, 60°, and 90°. The maximum resistance forces of miniscrews in pullout and shear tests were determined as primary stability using a universal testing machine. RESULTS: In the pullout tests, the 90° insertion angle had the highest primary stability. Oblique angulations of the miniscrews resulted in lower resistance. In the shear tests, angulations of the miniscrews from 90° to 45° led to increased primary stability. A more oblique insertion (30°) resulted in reduced primary stability. CONCLUSIONS: The direction of the applied force had a significant impact on the primary stability of miniscrews at various insertion angles. The highest primary stability values were achieved at 45° when the miniscrews were loaded by shear force and at 90° when pullout force was applied.


Asunto(s)
Tornillos Óseos , Mandíbula/cirugía , Métodos de Anclaje en Ortodoncia/instrumentación , Animales , Fuerza de la Mordida , Falla de Equipo , Técnicas In Vitro , Métodos de Anclaje en Ortodoncia/métodos , Resistencia al Corte , Ovinos , Soporte de Peso
13.
Electrophoresis ; 36(24): 2985-93, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26456026

RESUMEN

The electrophoretic migration of a highly charged spherical macroion suspended in an aqueous solution of NaCl is studied using the molecular dynamic method. The objective is to examine the effects of the colloidal surface charge density on the electrophoretic mobility (µ) of the spherical macroion. The bare charge and the size of the macroion are varied separately to induce changes in the colloidal surface charge density. Our results indicate that µ depends on colloidal surface charge density in a nonmonotonic manner, but that this relationship is independent of the way the surface charge density is varied. It is found that an increase in colloidal surface charge density may lead to the formation of new sublayers in the Stern layer. The µ profile is also found to have a local maximum for a bare charge at which a new sublayer is formed in the Stern layer, and a local minimum for a bare charge at which the outer sublayer becomes relatively dense. Finally, the electrophoretic flow caused by the migration of the spherical macroion is studied to find that one decisive factor causing the electrophoretic flow is the ability of the macroion to carry anions in the electrolyte solution.


Asunto(s)
Electroforesis , Modelos Químicos , Simulación de Dinámica Molecular , Electricidad Estática , Propiedades de Superficie
15.
ACS Appl Mater Interfaces ; 16(25): 32169-32188, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38862108

RESUMEN

Offering a compelling combination of safety and cost-effectiveness, water-in-salt (WiS) electrolytes have emerged as promising frontiers in energy storage technology. Still, there is a strong demand for research and development efforts to make these electrolytes ripe for commercialization. Here, we present a first-principles-based molecular dynamics (MD) study addressing in detail the properties of a sodium triflate WiS electrolyte for Na-ion batteries. We have developed a workflow based on a machine learning (ML) potential derived from ab initio MD simulations. As ML potentials are typically restricted to the interpolation of the data points of the training set and have hardly any predictive properties, we subsequently optimize a classical force field based on physics principles to ensure broad applicability and high performance. Performing and analyzing detailed MD simulations, we identify several very promising properties of the sodium triflate as a WiS electrolyte but also indicate some potential stability challenges associated with its use as a battery electrolyte.

16.
Artículo en Inglés | MEDLINE | ID: mdl-38307631

RESUMEN

The lower face is an integral component of a beautiful face. Age-related changes in this region are so significant that they are often easily appreciated by patients. The aging process not only includes volume loss or downward fat repositioning, but also soft tissue laxity, skin changes, and even bony resorption. In the lower face, this results in sagging of the soft tissue leading to the formation of jowling, loss of an attractive well-defined jaw line, and a retruded chin. Both surgical and non-surgical options are available to reverse the aging signs; however, the popularity of non-surgical treatment has dramatically increased in last 2 decades.


Asunto(s)
Técnicas Cosméticas , Envejecimiento de la Piel , Humanos , Rejuvenecimiento , Mentón/cirugía , Envejecimiento , Ácido Hialurónico/uso terapéutico
17.
Heliyon ; 10(5): e26576, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38434386

RESUMEN

Members of Sarcophagidae are necrophagous and are commonly found on decaying carcasses; and their developmental forms are important indicators for the approximation of lowest postmortem interval (PMImin). This work describes the biological characteristics of Sarcophaga argyrostoma from Tehran, Iran. Various temperature regimes were applied to estimate the thermal summation constant (k) and thermal requirements for development of S. argyrostoma. Five growth proceedings, containing 1st ecdysis, 2nd ecdysis, wandering, pupariation and eclosion, were investigated under eight fixed temperature regimes (6-30 °C). The effects of fly age, freshness, and availability of oviposition substrate on oviparity and viviparity was studied. At 6 °C, no development occurs, and at 8 °C only the first ecdysis occurs. At temperatures between 10 and 30 °C, all immature stages proceeded to the adult stage, and thus immature development was analyzed at these six remaining temperatures. The development phases needed minimum (Dz ± SE) 5.4(0.4), 8.5(0.26), 5.3(0.44), 3.8(0.1), and 6.6 (0.6)°C to attain one of the succeeding developmental occasion, correspondingly. The approximated K for those five occasions were 15.04 ± 1.12, 12.62 ± 0.65, 140.36 ± 4.35, 14.59 ± 0.6, and 222.8 ± 4.18°-day (DD) accordingly. When the food substrate is available and fresh, the female prefers to lay eggs, no matter how old she is. However, the chance of ovoviviparity increased when no oviposition substrate was available. The truth that S. argyrostoma able to either larviposit or to lay eggs encompasses serious consequences for the precise estimation of the PMImin, as the existence of larvae resulting from eggs laid on the carcass could add hours (based on ambient temperature) to the PMImin.

18.
Plast Reconstr Surg ; 153(4): 915-926, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-37285218

RESUMEN

BACKGROUND: The latissimus dorsi-rib osteomyocutaneous free flap (LDRF) has been used for autologous reconstruction of large composite calvarial and scalp defects. In this study, the authors aim to present clinical and patient-reported outcomes after LDRF reconstruction. METHODS: An anatomical study was conducted to evaluate the distribution of the connecting perforators between the thoracodorsal and intercostal systems. An institutional review board-approved retrospective review of 10 patients who underwent LDRF with one or two ribs for treatment of cranial defects was conducted. Patient-reported outcomes regarding quality of life, neurologic status, and functional status were evaluated using validated surveys. One-way analysis of variance and post hoc Tukey tests were used for anatomical outcomes. Preoperative and postoperative scores were compared using paired t tests. RESULTS: The tenth rib (4.65 ± 2.01) followed by the ninth rib (3.7 ± 1.63) had the highest number of perforators. A combination of the ninth and eleventh ribs exhibited maximal perforator number and pedicle length. All patients had stable LDRF reconstructions. Eight patients completed both preoperative and postoperative questionnaires; Median clinical follow-up was 48 months (range, 34 to 70 months). Scores trended toward improvement but did not reach statistical significance on the Karnofsky Performance Scale ( P = 0.22), the Functional Independence Measure (Motor, P = 0.52; Cognitive, P = 0.55), or the Headache Disability Index ( P = 0.38). The minimum clinically important difference was surpassed, demonstrating improvement of function for 71% of patients on the Barthel Index and 63% on the Selective Functional Movement Assessment test. CONCLUSION: The LDRF can improve cognitive and physical functional status in complex patients with prior failed reconstructions for composite scalp and skull defects. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.


Asunto(s)
Colgajos Tisulares Libres , Mamoplastia , Músculos Superficiales de la Espalda , Humanos , Músculos Superficiales de la Espalda/trasplante , Calidad de Vida , Costillas/trasplante
19.
J Oral Maxillofac Surg ; 71(3): 577-87, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22868036

RESUMEN

PURPOSE: Synthetic conduits have been considered a viable option in nerve reconstructive procedures. They address the goal of entubulization and eliminate the disadvantages of autografts. However, despite all successful reports, none has contained regeneration characteristics, such as growth factors or essential cells, for nerve repair. The authors evaluated the capability of adipose-derived stem cells in Gore-Tex tubes to enhance facial nerve repair. MATERIALS AND METHODS: Undifferentiated mesenchymal stem cells were extracted from the autogenous adipose tissues of 7 mongrel dogs. The frontal branch of the facial nerve was transected. A gap size of 7 mm was repaired with an expanded polytetrafluoroethylene tube filled with undifferentiated adipose-derived stem cells encapsulated in alginate hydrogel. The control sides were repaired with the tube and alginate alone. The healing phase was 12 weeks. RESULTS: Except in 2 control sides, an organized neural tissue was formed within the tubes. Compared with the normal nerve diameter, there was a decreased ratio of 29% and 39% in the experimental and control groups, respectively. Neurofilament-positive axon counts were 67% of normal values in the 2 groups. There was no significant difference between groups in histomorphometric parameters. Nerve conduction velocity in the experimental group (28.5 ± 3.5 m/s) was significantly greater than in the control group (16.2 ± 7 m/s). The experimental group also exhibited a greater maximal amplitude of action potential (1.86 ± 0.24 mV) than the control group (1.45 ± 0.49 mV). CONCLUSIONS: Addition of stem cells in the Gore-Tex tube enhanced the neural repair from a functional standpoint. However, for better functional and histologic results, differentiated Schwann cells and other mediators may be warranted.


Asunto(s)
Tejido Adiposo/citología , Nervio Facial/cirugía , Intubación , Trasplante de Células Madre Mesenquimatosas , Regeneración Nerviosa , Alginatos , Animales , Perros , Traumatismos del Nervio Facial/cirugía , Hidrogel de Polietilenoglicol-Dimetacrilato , Intubación/instrumentación , Politetrafluoroetileno
20.
J Chem Theory Comput ; 19(17): 5712-5730, 2023 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-37528639

RESUMEN

Accurate modeling of highly concentrated aqueous solutions, such as water-in-salt (WiS) electrolytes in battery applications, requires proper consideration of polarization contributions to atomic interactions. Within the force field molecular dynamics (MD) simulations, the atomic polarization can be accounted for at various levels. Nonpolarizable force fields implicitly account for polarization effects by incorporating them into their van der Waals interaction parameters. They can additionally mimic electron polarization within a mean-field approximation through ionic charge scaling. Alternatively, explicit polarization description methods, such as the Drude oscillator model, can be selectively applied to either a subset of polarizable atoms or all polarizable atoms to enhance simulation accuracy. The trade-off between simulation accuracy and computational efficiency highlights the importance of determining an optimal level of accounting for atomic polarization. In this study, we analyze different approaches to include polarization effects in MD simulations of WiS electrolytes, with an example of a Na-OTF solution. These approaches range from a nonpolarizable to a fully polarizable force field. After careful examination of computational costs, simulation stability, and feasibility of controlling the electrolyte properties, we identify an efficient combination of force fields: the Drude polarizable force field for salt ions and non-polarizable models for water. This cost-effective combination is sufficiently flexible to reproduce a broad range of electrolyte properties, while ensuring simulation stability over a relatively wide range of force field parameters. Furthermore, we conduct a thorough evaluation of the influence of various force field parameters on both the simulation results and technical requirements, with the aim of establishing a general framework for force field optimization and facilitating parametrization of similar systems.

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