We present a general scheme for the study of frustration in quantum systems. We introduce a universal measure of frustration for arbitrary quantum systems and we relate it to a class of entanglement ...monotones via an exact inequality. If all the (pure) ground states of a given Hamiltonian saturate the inequality, then the system is said to be inequality saturating. We introduce sufficient conditions for a quantum spin system to be inequality saturating and confirm them with extensive numerical tests. These conditions provide a generalization to the quantum domain of the Toulouse criteria for classical frustration-free systems. The models satisfying these conditions can be reasonably identified as geometrically unfrustrated and subject to frustration of purely quantum origin. Our results therefore establish a unified framework for studying the intertwining of geometric and quantum contributions to frustration.
Summary
Background
Surgical excision represents the most common elective treatment for basal cell carcinoma (BCC). Several noninvasive approaches have been proposed for in vivo determination of ...tumour margin, in order to achieve radical removal.
Objectives
To propose a new approach through the combination of dermoscopy and reflectance confocal microscopy (RCM) for lateral margin detection in BCC.
Methods
Ten patients with lesions clinically suggestive of nonpigmented BCCs with ill‐defined margins were enrolled. All BCCs were dermoscopically evaluated first and the ill‐defined margins were marked with a superficial cut and then inspected using RCM.
Results
RCM evaluation showed BCC foci beyond the presurgical marker in three out of 10 lesions. Histology confirmed the RCM results: the presence of BCC features across the cut, corresponding to two superficial BCCs and a morpheaform BCC.
Conclusions
This new procedure helped to improve the identification of proper margins for surgical excision in nonpigmented BCC with clinically and dermoscopically ill‐defined margins.
What's already known about this topic?
Mohs surgery is considered the most efficient technique for complete removal of basal cell carcinoma (BCC), but it is time consuming and expensive.
What does this study add?
The suggested procedure of dermoscopy combined with reflectance confocal microscopy helps to improve the identification of proper margins for surgical excision of BCC.
Plain language summary available online
Background
Lentigo maligna may be challenging to clear surgically.
Objective
To evaluate feasibility of using superficial skin cuts as RCM imaging anchors for attaining negative surgical margins in ...lentigo maligna.
Methods
Included patients presented with lentigo maligna near cosmetically sensitive facial structures. We evaluated, with hand‐held‐RCM, microscopic clearance of melanoma beyond its dermoscopically detected edges. Evaluated margins were annotated using shallow skin cuts. If a margin was positive at ‘first‐step’ RCM evaluation, we sequentially advanced the margin radially outward at that segment by 2‐mm intervals until an RCM‐negative margin was identified. Prior to final surgical excision, we placed sutures at the outmost skin cuts to allow comparison of RCM and histopathological margin assessments. Primary outcome measure was histopathological verification that RCM‐negative margins were clear of melanoma.
Results
The study included 126 first‐step margin evaluations in 23 patients, median age 70 years (range: 43–91). Seventeen patients (74%) had primary in‐situ melanoma and six (26%) invasive melanoma, mean thickness 0.3 mm (range 0.2–0.4 mm). Six cases (26%) showed complete negative RCM margins on ‘first‐step’, 11 (48%) were negative at ‘second‐step’, and four (17%) at ‘third‐step’. In two additional cases (9%), margins clearance could not be determined via RCM due to widespread dendritic cells proliferation. The RCM‐negative margins in all 21 cases proved clear of melanoma on histopathology. Of the 15 cases that returned at 1‐year follow‐up, none showed any residual melanoma on dermoscopic and RCM examinations. Interobserver reproducibility showed fair agreement between bedside RCM reader and blinded remote‐site reader, with Spearman's rho of 0.48 and Cohen's kappa of 0.43; using bedside reader as reference, the remote reader's sensitivity was 92% and specificity 57% in positive margin detection.
Conclusions
Margin mapping of lentigo maligna with hand‐held‐RCM, using superficial skin cuts, appears feasible. This approach needs validation by larger studies.
Management of psoriasis in elderly patients can be challenging, because of the impairment of immune system efficiency and the presence of comorbidities that contra-indicate systemic therapies. We ...studied the safety and efficacy of systemic traditional and biological treatments in 187 consecutive psoriatic patients aged > 65 years. At week 12 of therapy, Psoriasis Area and Severity Index 75 was achieved by 49%, 27%, 46% and 31% of patients who received methotrexate, acitretin, cyclosporine or PUVA, and 64.1%, 64.7%, 93.3%, 57.1% and 100% of patients who received etanercept, adalimumab, infliximab, efalizumab and ustekinumab. The rate of adverse events was 0.12, 0.32, 1.4 and 0.5 per patient-year in the methotrexate, acitretin, cyclosporine and PUVA groups and 0.11, 0.35, 0.19, 0.3 and 0.26 in the etanercept, adalimumab, infliximab, efalizumab and ustekinumab groups. Traditional drugs were less effective than biologics in our elderly population. Etanercept was associated with a lower rate of adverse events compared with other treatments.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
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The Pacman flap is a modified V-Y advancement flap that showed to be versatile in repairing surgical and non-surgical wounds. Indeed, this flap has been used in any anatomical ...localization, except for the scalp, where its use has not been reported. Moreover, the versatility of the Pacman flap can be enhanced by applying simple modifications to its original design.
A case-series of 23 patients whose surgical breaches were repaired using standard or modified Pacman flap were included in this retrospective study.
Most patients were male (65.2%) with a median age of 75.7 years. Squamous cell carcinoma was the tumor most commonly removed (60.9%), while scalp and face were the most frequent localizations (30.4%). Although 18 flaps were sculpted in the traditional Pacman shape, 5 were modified to fit the defect and localization. Complications occurred in 30% of flaps, but all of them were minor except for 1 extended necrosis.
The Pacman flap can be used to repair surgical wounds localized in any body area, including the scalp. Three modifications can enhance the versatility of the flap and offer new repair options to dermatologic surgeons.
El colgajo Pacman es un colgajo de avance V-Y modificado, que resulta versátil para la reparación de las heridas quirúrgicas y no-quirúrgicas. De hecho, este colgajo ha sido utilizado en cualquier localización anatómica excepto en el cuero cabelludo, donde no se ha descrito su aplicación. Además, aplicando simples modificaciones al diseño original del colgajo Pacman se aumenta su versatilidad.
Se realizó un estudio retrospectivo con una serie de casos de 23 pacientes en los que se empleó el colgajo Pacman estándar o modificado en la reconstrucción de sus heridas quirúrgicas.
La mayoría de los pacientes fueron varones (65,2%) con una media de edad de 75,7 años. La mayoría de las extirpaciones fueron de carcinoma escamoso cutáneo (60,9%). Las localizaciones más frecuentes fueron el cuero cabelludo y la cara (30,4%). Aunque 18 colgajos se diseñaron siguiendo las directrices originales del colgajo Pacman, 5 fueron modificados para adaptarlo al defecto y la localización. El 30% de los colgajos desarrollaron complicaciones, todas ellas menores a excepción de un caso de necrosis extensa.
El colgajo Pacman puede utilizarse para reparar defectos quirúrgicos en cualquier localización corporal, incluyendo el cuero cabelludo. Mediante 3 sencillas modificaciones puede mejorarse la versatilidad de este colgajo y ofrecer una nueva opción reconstructiva a los cirujanos dermatológicos.
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