Quick methylene blue dye elimination via SDS-Ag nanoparticles catalysts.

Methylene blue dye, being toxic, carcinogenic and non-biodegradable, poses a serious threat for human health and environmental safety. The effective and time-saving removal of such industrial dye necessitates the use of innovative technologies such as silver nanoparticle-based catalysis. Utilizing a pulsed Nd:YAG laser operating at the second harmonic generation of 532 nm with 2.6 J energy per pulse and 10 ns pulse duration, Ag nanoparticles were synthesized via an eco-friendly method with sodium dodecyl sulphate (SDS) as a capping agent. Different exposure times (15, 30, and 45 min) resulted in varying nanoparticle sizes. Characterization was achieved through UV-Vis absorption spectroscopy, scanning electron microscopy (SEM) imaging, and energy dispersive X-ray (EDX). Lorentzian fitting was used to model nanoparticle size, aligning well with SEM results. Mie's theory was applied to evaluate the absorption, scattering, and extinction cross-sectional area spectra. EDX revealed increasing Ag and carbon content with exposure time. The SDS-caped AgNPs nanoparticles were tested as catalyst for methylene blue degradation, achieving up to 92.5% removal in just 12 min with a rate constant of 0.2626 min-1, suggesting efficient and time-saving catalyst compared to previously reported Ag-based nanocatalysts.

Surgical outcomes and predictors of complication in elderly patients with meningiomas.

BACKGROUND: Surgical management of symptomatic meningioma in elderly is still a high-risk surgery due to increased incidence of complication rate. Many scoring systems have been proposed to expect the surgical risk and the outcome.The study tries to assess cranial meningioma surgery in elderly using the Ibañez grade for complication rate and the Geriatric Scoring System (GSS) for the surgical outcome (GSS). METHODS: A clinical and radiological data were studied retrospectively in 42 patients with a primary intracranial meningioma at or above the age of 65. Complication rate, surgical risk, and outcome were statistically analyzed. RESULTS: The mean Geriatric Scoring System (GSS) score on admission was 15.4 ± 2.6. Ibañez grade of severe complication or death (grades III-IV) were experienced in 26.2% of patients. It was more common in male and in emergency cases, but it was significant in relation to the comorbidities (P < 0.004). Most patients had World Health Organization (WHO) grades I lesions, accounted for 85.7% of patients. MRI evidence of post-surgical residual was 14.4%, and 83.3% of patients had recurrence-free survival (RFS). The GSS score >16 were more frequent in the patient with RFS than those of < 16, and it was statistically significant (P < 0.06). Patient with Karnofsky performance status (KPS) < 70, the mean GSS was 14.5 and KPS > 70, the mean GSS was 18.9, and it was statistically significant (P < 0.002). CONCLUSION: The surgical technique for resection of elderly meningioma still had numbered cases of morbidity and mortality. The complication rate is related to preoperative co-morbidity and frequently associated with male and urgent surgery. Karnofsky score > 70, and RFS are favorable prognosis and related to GSS > 16 scores. The recurrence rate is usually attributed to high tumor grade and skull base tumor. Such scoring systems are valuable for elderly meningioma.

Neutron optical beam splitter from holographically structured nanoparticle-polymer composites.

We report a breakthrough in the search for versatile diffractive elements for cold neutrons. Nanoparticles are spatially arranged by holographical means in a photopolymer. These grating structures show remarkably efficient diffraction of cold neutrons up to about 50% for effective thicknesses of only 200   µm. They open up a profound perspective for next generation neutron-optical devices with the capability to tune or modulate the neutron diffraction efficiency.

Temperature dependence of optical anisotropy of holographic polymer-dispersed liquid crystal transmission gratings.

We measured the angular dependence of the 0th, +/-1 st, and +/-2 nd optical diffraction orders from a 50 microm thick transmission grating recorded in a UV-curable holographic polymer-dispersed liquid crystal (HPDLC) made from commercially available constituents. The analysis was performed for two orthogonal polarizations of the probe beams. The emphasis was laid on the temperature dependence of the grating anisotropy. Above the nematic-isotropic phase transition, the grating is optically isotropic. At lower temperatures the grating strength for the optical polarization perpendicular to the grating vector decreases with decreasing temperature, while for orthogonal polarization it increases with decreasing temperature. As a consequence, a regime of diffraction with strongly overmodulated gratings is observed. Our investigations indicate that the anisotropy of the refractive-index modulation scales with the optical anisotropy of the liquid crystal medium forming the phase-separated domains. We further demonstrate that light scattering effects, which are profound only in the nematic phase, must not be neglected and can be taken into account via a Lorentzian line-shape broadening of the probing wave vector directions in the framework of the diffraction theory for anisotropic optical phase gratings.

Patterns of sensory and autonomic reinnervation of long-standing myocutaneous microvascular flaps and split-skin grafts applied to fascial beds.

BACKGROUND: There is a paucity of reports in the literature examining the pattern of sensory and autonomic neural recovery of myocutaneous microvascular flaps and skin grafts to the lower limbs after a prolonged period of time. OBJECTIVES: To investigate the recovery of sensation and autonomic nerve activity in long-standing split-skin grafts applied to fascial beds and in myocutaneous microvascular flaps. METHODS: THE PATIENTS WERE DIVIDED INTO TWO GROUPS: group A consisted of patients with a split-skin graft applied to a fascial bed (n=11) and group B consisted of patients with free microvascular flaps (n=4). Patients in both groups underwent various clinical subjective and objective tests, including the measurement of electrical resistance and thermal sensory analysis. Laser Doppler flowmetry was used to investigate the blood flow patterns. RESULTS: Patients in both groups showed significantly reduced sensory modalities. However, the findings of both the electrical resistance and laser Doppler flowmetry were significantly different among the patients in group A compared with controls. In contrast, electrical resistance and laser Doppler flowmetry test results were similar in group B and controls. CONCLUSIONS: Both split-skin grafts applied to fascial beds and microvascular flaps on the lower limb had poor sensory recovery. However, after 15 years, the microvascular flaps regained the ability to sweat and some degree of thermoregulatory function. This may imply that the long-standing myocutaneous free flaps regained some aspects of their autonomic innervation, whereas the split-skin grafts had not.

HISTORIQUE: La documentation scientifique fait état de peu de comptes rendus sur le motif de rétablissement neuronal sensoriel et neurovégétatif de lambeaux microvasculaires myocutanés et de greffes cutanées dans les membres inférieurs après une période prolongée. OBJECTIFS: Étudier le rétablissement de l'activité nerveuse sensorielle et neurovégétative dans des greffes dermo-épidermiques aponévrotiques de longue date et dans des lambeaux microvasculaires myocutanés. MÉTHODOLOGIE: Les patients ont été séparés en deux groupes : le groupe A se composait de patients ayant une greffe dermo-épidermique aponévrotique (n=11) et le groupe B, de patients présentant des lambeaux microvasculaires libres (n=4). Les patients des deux groupes ont subi divers tests cliniques subjectifs et objectifs, y compris une mesure de la résistance électrique et une analyse sensorielle thermique. Une débitmétrie Doppler à laser a permis d'examiner les motifs de débit sanguin. RÉSULTATS: Les patients des deux groupes ont affiché une diminution considérable des modalités sensorielles. Cependant, les observations tant de la résistance électrique que de la débitmétrie Doppler à laser différaient de manière significative entre les patients du groupe A et ceux du groupe témoin. Par contre, ces résultats étaient similaires entre les patients du groupe B et ceux du groupe témoin. CONCLUSIONS: Tant les greffes dermo-épidermiques aponévrotiques que les lambeaux microvasculaires des membres inférieurs comportaient une faible récupération sensorielle. Cependant, au bout de quinze ans, les lambeaux microvasculaires avaient recouvré la capacité de sudation et un certain degré de fonction thermorégulatoire. D'après ce phénomène, les lambeaux libres myocutanés de longue date pourraient retrouver certains aspects de leur innervation neurovégétative, contrairement aux greffes dermo-épidermiques.

Patterns of reinnervation and blood flow in split-skin grafts.

One of the most important functions of skin is thermoregulation. The alterations in the patterns of blood flow in skin is one of the main physiological processes responsible for thermoregulatory control. The mechanisms governing the thermoregulatory control of cutaneous blood flow are mainly neural and chemical in nature. At present, there is a lack of studies in the literature looking at the relationship between reinnervation and the blood flow pattern of skin grafts. The present study uses Laser Doppler flowmetry and the immunohistochemical stains protein gene product 9.5, calcitonin gene-related peptide and substance P to identify nerve fibres, and antibodies to CD31 and von Willebrand factor to identify endothelial tissues. The aim of the present study was to investigate the patterns of blood flow and nerve tissue regeneration in split-skin grafts up to 15 years following the original procedure. Thirty-two split-skin grafts were studied and these were placed into two groups based on the nature of the bed of excision: group I consisted of patients who underwent tangential excision and split-skin grafting (n=17), and group II consisted of patients with split-skin grafts placed onto fascial beds (n=15). Each subpopulation of patients was further divided into three groups based on the length of time following grafting: one to three years, four to six years and seven to 15 years. These divisions were arbitrarily chosen and called A1, A2 and A3, respectively. In the Laser Doppler flowmetry arm of the study, the grafts were assessed at various stages after heating, cooling and further reheating. The Laser Doppler flowmetry studies showed that, on subjecting the skin grafts in both groups I and II to heating and cooling followed by reheating, the overall response of the blood flow to changes in the temperature was slower. The immunohistochemical analysis showed that in all graft types and graft ages, protein gene product 9.5, calcitonin gene-related peptide and substance P stains demonstrated a relative lack of the presence of nerve fibres in the split-skin grafts compared with the control ('normal' skin). However, von Willebrand factor and CD31 immunological staining demonstrated that vessels were present in the split-skin grafts, with no significant difference in size or quantity from the control samples. It was found that the blood flow in the split-skin graft in response to thermal challenge, although present, was slower than that of normal skin, a finding which was independent of the age of the skin graft. It is thought that this was related to a lack of regeneration of nerve fibres and, hence, a deficiency in the neurally mediated reflexes of the blood vessels within the split-skin grafts.

L'une des plus importantes fonctions de la peau est la thermorégulation. Les altérations de la circulation sanguine dans la peau demeurent parmi les principaux processus physiologiques à l'origine de la thermorégulation. Les mécanismes qui régissent la thermorégulation de la circulation sanguine cutanée sont principalement de nature neurale et chimique. Encore trop peu d'études ont été faites et publiées à propos du lien entre la réinnervation et la circulation sanguine dans les greffes cutanées. La présente étude repose sur l'utilisation de la débitmétrie Doppler à laser et sur des colorations immunohistochimiques avec le produit du gène de protéine 9.5, le peptide lié au gène de la calcitonine et la substance P dans le but d'identifier les fibres nerveuses et les anticorps dirigés contre le CD31 et contre le facteur de von Willebrand pour visualiser les tissus endothéliaux. Le but de la présente étude était d'explorer les modes de régénération de la circulation sanguine et des tissus nerveux dans des greffes de demi-épaisseur, jusqu'à 15 ans après l'intervention originale. Trente-deux greffes de demi-épaisseur ont été étudiées et elles ont été classées en deux groupes selon la nature du lit d'excision : groupe I, composé de patients ayant subi une excision tangentielle et une greffe de demi-épaisseur (n = 17) et groupe II, comportant des patients ayant subi des greffes de demi-épaisseur de fascias (n = 15). Chaque sous-groupe de patients a été de nouveau divisé en trois groupes selon la durée des greffons : 1 à 3 ans, 4 à 6 ans et 7 à 15 ans. Ces subdivisions ont été choisies arbitrairement et nommées A1, A2 et A3, respectivement. Dans le groupe de l'étude soumis à la débitmétrie Doppler à laser, les greffons ont été évalués à divers stades après application de chaleur, de froid et de chaleur à nouveau.Les analyses de débitmétrie Doppler à laser ont montré qu'en soumettant les greffons cutanés des groupes I et II à la chaleur puis au froid, suivi de chaleur à nouveau, la réponse globale de la circulation sanguine aux changements de température était plus lente.L'analyse immunohistochimique a montré que dans tous les types de greffe, la coloration par produit du gène de protéine 9.5, peptide lié au gène de la calcitonine et substance P a révélé une absence relative de fibres nerveuses dans les greffes de demi-épaisseur comparativement aux témoins (peau « normale ¼). Par contre, la coloration immunologique du facteur de von Willebrand et du CD31 a montré que les vaisseaux étaient absents des greffes de demi-épaisseur sans différence significative de taille ou de quantité comparativement aux échantillons témoins.On a découvert que la circulation sanguine dans le greffon de demi-épaisseur en réponse aux changements de température, bien que présente, est plus lente que dans la peau normale, un phénomène qui serait indépendant de l'âge du greffon et que l'on croit relié à l'absence de régénération des fibres nerveuses et donc à un déficit des réflexes neuraux des vaisseaux sanguins dans les greffons de demi-épaisseur.

Body contouring by combined abdominoplasty and medial vertical thigh reduction: experience of 14 cases.

The common perception of beauty in the human body has shown a dramatic change over the past few decades culminating in a preoccupation not only with body weight, but also with body image. Obesity is becoming prevalent in our society, and yet generalised redundancy of skin following massive weight reduction can also be an affliction. Localised fat deposits in one or more regions of the trunk, upper arms and thighs are common and are virtually impossible to correct by diet, weight loss or exercise. Excision of the excess pendulous skin and/or the localised fat deposits are able to reduce or even eliminate the physical problems associated with the condition and contribute significantly to patient self-esteem. These procedures are usually multiple and extensive. Combining and reducing the number of such procedures while obtaining optimal results would be most beneficial to both the surgeon and the patient. We report our experience of 14 patients who underwent body contouring operations using combined abdominoplasty and medial thigh reduction with analysis of the results and discussion of the requirements and the advantages of the technique.

Subcutaneous metallic mercury injection of the hand.

Poisoning by subcutaneous metallic mercury is rare and usually accidental. Although it does not carry the same risks as mercury-vapour intoxication, it may still cause destructive early and late local reactions. Two deaths resulting from subcutaneous mercury injection have been reported in the literature. We present a case of accidental subcutaneous injection of mercury in the hand and discuss its management with a review of the literature.