Size scaling of mesoporous silica membranes produced by nanosphere mediated laser ablation.

Monodisperse silica nanospheres with sizes ranging from 250 to 725 nm were prepared and assembled into monolayers to produce regularly distributed light hot spots at the surface of oxidized silicon substrates when illuminated by a laser. Single UV nanosecond laser pulses were employed with energies above the local ablation threshold for the silicon dioxide layer, resulting in the direct formation of 2D periodically porous membranes on top of the silicon. The periodicity of the array was driven by the size of the self-assembled nanospheres. While the local field enhancement was strongly dependent on the sphere size due to Mie resonances, the size and morphology of the produced features could be maintained for all tested situations by balancing the change in local fields with the laser pulse energy. This work demonstrates the fabrication of 90 nm thick porous membranes with pore size of about 100 nm and periodicity ranging from 250 to 725 nm.

Correction to: Transsphenoidal surgery for pituitary adenomas: early results from a single center.

Unfortunately in the original publication, the affiliation of the author Paolo Marzullo was incorrect. The author inadvertently missed out to include his second affiliation.

Transsphenoidal surgery for pituitary adenomas: early results from a single center.

OBJECTIVE: To evaluate early results of transsphenoidal surgery for pituitary adenomas. DESIGN: Retrospective evaluation of 90 consecutive patients undergoing endoscopic pituitary adenoma surgery (2007-2016) at "Maggiore della Carità" Hospital in Novara, Italy. Age at diagnosis, sex, symptoms at presentation, hormonal and radiological data, complications of surgery, and short-term follow-up information were collected. RESULTS: The majority of patients were male (M/F: 1.5/1, mean age at diagnosis 62.1 ± 1.5 years mean ± SEM). Most patients (91.1%) presented with a macroadenoma (27.4 mm ± 1.1 mm mean ± SEM), while 77.8% were non-functioning pituitary adenomas. Clinical presentations related to mass effect were visual impairment (74.0%) and/or hypopituitarism (55.1%). The main surgery complication was insipidus diabetes (12.2%), followed by cerebral hemorrhage (4.4%), cerebrospinal fluid (CSF) leaks (4.4%), syndrome of inappropriate antidiuresis (SIAD) (2.2%), and epistaxis (2.2%); only one patient died because of stroke. Risk of complications was not associated with tumor size (OR = 0.588, 95% CI 0.967-1.081, p = 0.443). Visual function improved in 70.6% of patients, while recovery of normal pituitary function occurred in 48.1%. Early neuroimaging studies demonstrated no residual tumor in 27.6% of patients. Invasion of cavernous sinus (OR = 3.293, 95% CI 0.897-16.738, p = 0.05) and maximum tumor diameter (OR = 6.857, 95% CI 1.039-1.309, p < 0.01) were associated with an unfavorable surgical outcome. CONCLUSIONS: Transsphenoidal endoscopic surgery for pituitary adenomas is safe and is frequently followed by improvement in visual symptoms, whereas recovery of pituitary function is less common. In our patients, complete surgical removal of adenomas is comparable to that of other series, but further investigations will be necessary to clarify the long-term risk of tumor recurrence.

Patterning of polymer brushes made easy using titanium dioxide: direct and remote photocatalytic lithography.

Photocatalytic lithography is proved for the realization of micropatterned polymer brushes. Initiator-functionalized titanium dioxide or silicon surfaces are respectively exposed directly to near-UV light through a photomask (direct approach) or through a transparent photoactive TiO2 film (remote approach). Initiator patterns are then amplified as polymer brushes with SI-ATRP. Features down to 10 µm could be obtained using simple equipment. The process is intrinsically parallel, has high throughput and scalable to wafer size, making it powerful for microfabrication purposes.

Intracranial fibromuscular dysplasia. Report of two cases and review of literature.

Intracranial fibromuscular dysplasia (IFMD) is a rare angiopathy of unknown origin primarily affecting children and young women. We report here on two cases of IFMD; the patients, two females, aging 29 and 25 years, suffered from acute, complete stroke. In one of them emergency extra-intracranial by-pass was attempted without evidence of positive influence on the patient's outcome. In both patients angiography showed the pathognomonic sign of "string of bead" at the level of intracerebral arteries. Cases of IFMD previously reported in the literature are then reviewed and etiology, clinical presentation, pathology, diagnosis and possible treatment of this rare disease are discussed.

Hemispheric cavernous angiomas: presumptive preoperative diagnosis.

Clinical history, CT scan and angiography may lead to a correct preoperative diagnosis of hemispheric cavernous angiomas. Surgical results and follow-up are favorable; considering the bleeding risk we think the operation to be mandatory.

[Hemangiopericytoma of the petrous bone. Considerations apropos of 5 surgically treated cases]. / Les hémangiopéricytomes du rocher. Considérations à propos de 5 cas opérés.

5 cases of infratentorial hemangiopericytomas involving petrous bone are described. They show significant tendency to invade and destroy the bony base reaching into the soft parapharyngeal tissue of the neck. Radiography, tomography and CT scan of the skull demonstrate a large erosion of the petrous bone. At CT scan the lesion appears slightly hyperdense with marked enhancement. Selective angiography shows an important vascular supply from the external carotid artery, the deep and ascending cervical arteries and the extracranial part of the vertebral artery. Embolisation or surgical occlusion of the branches of external carotid artery and cervical arteries are useful to reduce bleeding during biopsy. Radiotherapy is advisable.

[Cystic meningioma simulating glioblastoma in x-ray computed tomography]. / Les méningiomes kystiques simulateurs de glioblastomes en tomodensitométrie.

Seven cases of supratentorial meningiomas are reported. CT-Scan showed irregular hypo-hyperdense zones and features of intratumoral cysts. At surgery a well circumscribed tumor has always been found and easily removed "en bloc". In two cases stereotaxic biopsy was performed previously. CT-Scan findings of meningiomas with microcystic structure and/or necrotic areas may mimic a malignant glioma and lead to an incorrect presumptive diagnosis: then, both therapy and prognosis will be very different. It comes that stereotaxic biopsy is mandatory in all suspected cases of cerebral tumors, in the absence of classical angiographic patterns.

[Neuroanesthesia during carotid thromboendarterectomy interventions]. / Neuroanestesia durante gli interventi di TEA carotidea.

The paper describes two techniques of anesthesia used during carotid thromboendarteriectomy surgery. The first technique utilises a mixture of O2-N2O, isofluorane and fentanyl as analgesic; the halogenate compound is not administered during carotis clamping and fentanyl is used for maintenance. The second technique is predominantly intravenous and utilises differing doses of propofol during the entire operation with fentanyl as an analgesic. The two techniques are comparable in terms of management and efficacy; the use of ECG monitoring is vital to identify possible intraoperative cerebral ischemic phenomena.

Early postoperative angiographic findings after carotid endarterectomy.

This report reviews the early postoperative evaluation of 70 patients who underwent carotid bifurcation endarterectomy within our department (before patients' releasing). Angiography was performed by femoral catheterization or the retrograde brachial route; three times only digital venous techniques were employed. No complications due to radiological procedures occurred. Postoperative angiographic findings include asymptomatic occlusion of ICA, occlusion of ECA, the presence of mural thrombi, diffuse surface roughness, intimal flaps and kink of ICA. Dilatation of the arteriotomized segment was detected with a high rate of frequency. Postoperative vascular changes are then analyzed in relation to surgical techniques, to early postoperative clinical course and to the occurrence of late re-stenoses.

Course of intracranial pressure after extirpation of posterior fossa tumours.

Forty-seven patients with posterior fossa tumours underwent continuous monitoring of intracranial pressure (ICP) in the early postoperative period by means of an intraventricular catheter. ICP values were very low on the day of operation and subsequently became normal in 37 patients. ICP values were raised in 10 patients. The relationship between the ICP and the clinical course was investigated. Patients were subdivided according to the clinical postoperative course into three groups: good, temporarily deteriorated, poor clinical course. The two first groups showed lower values in the ICP than he third one, nevertheless the relationship between the ICP and the postoperative clinical course is marked but not strict. Our data may have some clinical relevance for the treatment of hydrocephalus before extirpation of posterior fossa tumours.

Prognostic meaning of temporary clipping in patients with intracranial aneurysm.

The prognostic meaning of the routine use of the methods of temporary clipping of the afferent vessel in patients with intracranial aneurysm (Grading 0-III) was the aim of the analysis in this study. In the period 1 January, 1991-31 December 1997, 304 patients underwent surgery for non-giant intracranial aneurysm and a follow-up angiography. 157 patients were operated by routinely using the temporary clipping of the afferent vessel, whereas in 147 patients the surgical procedure was performed by traditional methods. The statistical analysis showed a significant reduction (p < 0.001) in terms of risk of surgical complications in the patients who underwent surgery with the temporary clip method compared to those operated with the traditional method, with a relative risk of such complications about three times greater in the latter. The routine use of temporary clipping offers, therefore, the possibility of a significant improvement of the surgical results, not influenced by a further involvement for the structure, due to the short application time.