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Biomaterials often contain large quantities of water (50-98%), and with the current transition to a more biobased economy, drying these materials will become increasingly important. Contrary to the standard, thermodynamically inefficient chemical and thermal drying methods, dewatering by membrane separation will provide a sustainable and efficient alternative. However, biomaterials can easily foul membrane surfaces, which is detrimental to the performance of current membrane separations. Improving the antifouling properties of such membranes is a key challenge. Other recent research has been dedicated to enhancing the permeate flux and selectivity. In this review, we present a comprehensive overview of the design requirements for and recent advances in dewatering of biomaterials using membranes. These recent developments offer a viable solution to the challenges of fouling and suboptimal performances. We focus on two emerging development strategies, which are the use of electric-field-assisted dewatering and surface functionalizations, in particular with hydrogels. Our overview concludes with a critical mention of the remaining challenges and possible research directions within these subfields.
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Eletricidade , Água , Membranas Artificiais , Dessecação/métodos , Materiais BiocompatíveisRESUMO
AimGiant pituitary adenomas are difficult to resect due to multicompartmental extension. We developed a new grading system for giant pituitary adenomas (GPAs) considering possible extension in superior, lateral, anterior, and posterior (SLAP) directions. We also related the degree of resection to the SLAP grading.MethodsA review of case files and radiological images of patients with the GPAs defined as pituitary adenomas with a size of more than 4 cm in any dimension was done. The extent of the tumour was noted and scored as per the SLAP system. The maximum total score is 10 and represents a large tumour with maximum extensions in all directions. The subtotal resection (STR) was defined as a residual tumour volume of more than 10%. The association between individual and total score on the degree of resection was determined.ResultsA total of 103 cases of GPAs were analyzed. All patients had a suprasellar (S) extension. The lateral (L) extension was seen in 97.3% of cases. The anterior (A) extension was seen in 28 (27.2%) cases. The posterior (P) extension was seen in 45 (43.7%). Forty-eight (46.6%) had a total score of 5 or more. The STR was achieved in 64 (62.2%) cases. On regression analysis, a total score of ≥5 was associated with odds of 5.02 (1.69-14.93), p-value 0.004 for STR.ConclusionThe SLAP grading is a comprehensive grading system that can be applied easily to the GPAs and gives a complete picture of the extension of the tumour.
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Adenoma , Neoplasias Hipofisárias , Adenoma/complicações , Adenoma/diagnóstico por imagem , Adenoma/cirurgia , Humanos , Imageamento por Ressonância Magnética , Neoplasia Residual , Neoplasias Hipofisárias/complicações , Neoplasias Hipofisárias/diagnóstico por imagem , Neoplasias Hipofisárias/cirurgia , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Introduction Trigeminal schwannoma surgery has shown a remarkable improvement in functional recovery and tumor resection. In the era of radiosurgery, these outcomes need to be characterized for tumors which are outside the realm of being treated with radiosurgery. We present a series of trigeminal schwannomas larger than 3 cm, surgical approaches used, and outcomes with an emphasis on functional recovery in a high-volume center with radiosurgery facilities. Method All consecutive cases of trigeminal schwannoma from January 2012 to May 2021 which were more than 3 cm in size and underwent microsurgery were included in this series. The surgical approach, neurological outcomes, and extent of resection were defined objectively with pre/postoperative magnetic resonance imaging. Results A total of 83 such cases (>3 cm) were found, with cranial nerve symptoms (5th most common) being the commonest. Twenty three percent cases had blindness due to secondary optic atrophy and eighteen percent had long tract motor symptoms signifying the tumor burden in our series. Radiological gross total excision was achieved in 75.9% cases. Conclusion Large-volume schwannomas present with cranial nerve involvement and may need extensive skull base approaches. Functional outcomes need to be prioritized and can be achieved albeit with lesser gross resection rates. Hearing and facial preservation in addition to relief of trigeminal symptoms should be the goal of resection with minimal additional morbidity.
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OBJECTIVE: Rosai-Dorfman disease (RDD) is a rare benign proliferative disorder of histiocytes. The study discusses the intracranial RDD approach, its management, and its outcome. METHODS: It is a retrospective study performed in a tertiary center, the National Institute of Mental Health and Neuroscience, Bangalore, from January 2010 to December 2022. The biopsy-proven patients of RDD were recruited in the present cohort. Demographic and surgical details were collected from the record section, and radiology was collected from the internal storage system. Follow-up assessments were done clinically and telephonically. RESULTS: A total of 25 patients matched the criteria. The mean age was 32 ± 13.4 years, with male predominance. We have included only cranial cases (N=25). Among the intracranial lesions, 5/25 (20 %) patients had multicentric lesions. All the lesions were avidly enhancing on contrast, and 16 (64 %) lesions were hypointense on T2. Perilesional edema (T2/Flair hyperintensities in the surrounding white matter) was seen in 12 (48 %) patients. Gross total resection (GTR) was carried out in six (24 %) cases. Sub-total resection was in 14 (56 %), and biopsy was in five cases (20 %). Nineteen patients received adjuvant therapy, either only steroid (40 %), only low-dose radiotherapy (16 %), only Chemotherapy (4 %), or a combination of both. At follow-up,44 % of patients had stable disease,28 % had primary disease or recurrence growth, and regression in 12 % of cases. CONCLUSION: We demonstrate that surgical resection is an effective therapy for treating isolated intracranial RDD. Adjuvant therapy is an add-on treatment for skull base locations in multicentric locations or surgically inaccessible locations.
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Histiocitose Sinusal , Humanos , Histiocitose Sinusal/cirurgia , Histiocitose Sinusal/terapia , Histiocitose Sinusal/patologia , Histiocitose Sinusal/diagnóstico , Masculino , Feminino , Adulto , Estudos Retrospectivos , Pessoa de Meia-Idade , Adulto Jovem , Adolescente , Encefalopatias/cirurgia , Encefalopatias/terapia , Encefalopatias/patologia , Procedimentos Neurocirúrgicos/métodos , Imageamento por Ressonância Magnética , Gerenciamento Clínico , Resultado do TratamentoRESUMO
BACKGROUND: Benign Nerve sheath tumors (NST) comprise almost one-third of primary spinal tumours. The majority are sporadic. They have low rates of recurrence but an occasional recurrence may need re-surgery. The present study was designed to identify the variables that can predict the risk of their recurrence. METHODS: A retrospective chart review was done including all the histologically proven benign spinal NSTs operated between 2001 and 2019 in our institute. Demographic, operative and postoperative follow-up data were recorded. Recurrence was defined as local reappearance after definite surgical excision or symptomatic increase in size of a residual tumour on follow-up imaging studies. Statistical analysis was done to determine the significant variables associated with local recurrence. RESULTS: 457 patients with a median age of 38 years operated for 459 NSTs qualified for the study. The most frequent location of occurrence of tumours was found to be Low Cervical level (C3-C7 levels). Majority of Schwannoma were located intradurally while Neurofibroma were dumb-bell shaped and extradural. Most of the tumours had solid consistency. Post operatively, 7.7% patients developed complications. 7.8% tumours developed local recurrence after median period of 12 months. The patients developing recurrence were younger compared to nonrecurring tumors. On univariate analysis, male gender, Low cervical and Cervicothoracic junction location were associated with higher recurrence. On multivariate analysis, location at Cervicothoracic junction reached significance. CONCLUSION: Overall recurrence risk among all NST was 7.8% with a median progression free survival of 36 months. The location of tumour at cervicothoracic location was the significant risk factors for recurrence of tumour in our study.