Assessment of Obesity as Risk Factor of Lumbar Disc Surgery: Retrospective Analysis of 598 Cases and Simulated Surgery on 3D-Printed Models.

: Obesity poses known risks in surgery, including a prolonged operation time and postoperative complications. Given the rising obesity rates and frequent lumbar disc surgeries, understanding these risks is crucial. This study aims to assess the impact of obesity on operation duration and postoperative complications in lumbar disc prolapse surgery.

Large language models: Are artificial intelligence-based chatbots a reliable source of patient information for spinal surgery?

Purpose: Large language models (LLM) have recently attracted attention because of their enormous performance. Based on artificial intelligence, LLM enable dialogic communication using quasi-natural language that approximates the quality of human communication. Thus, LLM could play an important role for patients to become informed.

[Decompressive craniectomy in traumatic brain injury and malignant brain infarction].

High intracranial pressure (ICP) is the most frequent cause of death and disability after severe traumatic brain injury and malignant cerebral infarction. After failure of general therapeutic maneuvers and first line therapies, "second tier" therapies have to be considered. Decompressive craniectomy is an advanced treatment option for controlling intracranial pressure (ICP).

Single integrated device for optical CDMA code processing in dual-code environment.

We report on the design, fabrication and performance of a matching integrated optical CDMA encoder-decoder pair based on holographic Bragg reflector technology. Simultaneous encoding/decoding operation of two multiple wavelength-hopping time-spreading codes was successfully demonstrated and shown to support two error-free OCDMA links at OC-24. A double-pass scheme was employed in the devices to enable the use of longer code length.

Diffraction-limited performance of flat-substrate reflective imaging gratings patterned by DUV photolithography.

We report on the first demonstration of flat substrate imaging gratings fabricated by deep ultraviolet (DUV) photoreduction lithography, which uniquely offers sub-100-nm resolution and spatial coherence over centimeter scales. Reflective focusing gratings, designed according to holographic principle, were fabricated on 300-mm silicon wafers by immersion DUV lithography. Spatial coherence of the fabrication process is evident in measured diffraction-limited imaging function.

Cerebral response to norepinephrine compared with fluid resuscitation in ovine traumatic brain injury and systemic inflammation.

Objective: Traumatic brain injury is frequently accompanied by a systemic inflammatory response. Systemic inflammation was associated with cerebral hyperperfusion uncoupled to global oxygen metabolism in ovine head trauma. The present study investigated the cerebral effects of cerebral perfusion pressure (CPP) management performed by either fluid resuscitation or vasopressor treatment of low CPP induced by systemic inflammation.

Electrophysiology in ischemic neocortical brain slices: species differences vs. influences of anaesthesia and preparation.

Ischemia models are indispensable for the evaluation of measures to be clinically applied to brain trauma or stroke patients. Slice models provide good control over experimental parameters and allow for comparative examinations of human and animal brain tissue. Experimental tissue, however, may be altered by anaesthesia, preparatory technique, and, in the case of human tissue, by underlying diseases.

Optical add-drop multiplexers based on the antisymmetric waveguide Bragg grating.

A novel optical add-drop multiplexer (OADM) based on a null coupler with an antisymmetric grating was designed and experimentally demonstrated. The antisymmetric grating exclusively produces a reflection with mode conversion in a two-mode waveguide. This improves the performance compared with previous demonstrations that used tilted Bragg gratings.

Juvenile psammomatoid ossifying fibroma of the neurocranium. Report of four cases.

Juvenile psammomatoid ossifying fibroma (JPOF) is a benign fibroosseous lesion predominantly arising within the paranasal sinuses in children and young adults. Neurocranial occurrence is exceedingly rare and a location within the neurocranial portion of the temporal bone has not been described. The authors report on one case of sinonasal JPOF secondarily extending into the cranial cavity and three cases primarily affecting the neurocranial bones to increase clinical awareness of this uncommon tumor, which may be easily mistaken for meningioma.

Demonstration of mode conversion using anti-symmetric waveguide Bragg gratings.

We experimentally demonstrate a novel grating which only produces reflection with mode conversion in a two-mode waveguide. That characteristic can improve the performance of optical devices that currently use tilted Bragg gratings to provide the mode conversion. Tilted Bragg gratings produce also reflections without mode conversion which increases noise and crosstalk of the optical device.

Low-loss silica-on-silicon two-dimensional Fabry-Perot cavity based on holographic Bragg reflectors.

We report on the demonstration of an integrated slab-waveguide-based concentric Fabry-Perot resonator that employs holographic Bragg reflectors as cavity mirrors. The cavity, produced in a low-loss silica-on-silicon slab waveguide by high-fidelity deep-ultraviolet photolithographic fabrication, exhibits a reflectivity-limited Q factor of approximately 10(5). Increasing the mirror's reflectivity will provide Q values similar to those of silica-based ring resonators, whereas the folded Fabry-Perot resonator design allows access to a substantially larger free spectral range by cavity shortening.

Cerebral vascular and metabolic response to sustained systemic inflammation in ovine traumatic brain injury.

Traumatic brain injury (TBI) is frequently accompanied by a systemic inflammatory response secondary to multiple trauma, shock, or infections. This study investigated the impact of sustained systemic inflammation on cerebral hemodynamics and metabolism in ovine traumatic brain injury. Fifteen sheep were investigated for 14 hours.

Wavelength division multiplexing based on apodized planar holographic Bragg reflectors.

We report wavelength division multiplexing based on lithographically fabricated slab-waveguide-contained planar holographic Bragg reflectors (HBRs). Partial HBR diffractive contour writing and contour displacement are successfully demonstrated to enable precise bandpass engineering of multiplexer transfer functions and make possible compact-footprint devices based on hologram overlay. Four- and eight-channel multiplexers with channel spacings of approximately 50 and approximately 100 GHz, improved sidelobe suppression, and flattop passbands are demonstrated.

Bandpass engineering of lithographically scribed channel-waveguide Bragg gratings.

We propose and demonstrate a powerful approach to spectral bandpass engineering (apodization) of one-dimensional channel-waveguide Bragg reflectors. Bandpass engineering is accomplished by precise photolithographic control of the length and the longitudinal placement of individual grating lines, which provides unique line-by-line diffractive amplitude and phase control. Channel-waveguide gratings that exhibit complex filtering functions have been fabricated and modeled.

Effective gray scale in lithographically scribed planar holographic Bragg reflectors.

We demonstrate that holographic Bragg reflector grating structures, which are photolithographically scribed in planar waveguides, support a unique approach to apodization and overlay that uses fixed-depth etching and partial contour writing to achieve continuous reflective amplitude control.

Different actions of gamma-hydroxybutyrate: a critical outlook.

Gamma-hydroxybutyrate acid (GHB) is a naturally occurring analog of GABA in the mammalian brain and can be therapeutically used for basic sedation in intensive care units. Although its application is discussed controversially, GHB is suspected to protect neuronal tissue against ischemic damage. GHB was tested for an acute effect on electrophysiologic parameters of guinea pig hippocampal tissues exposed to ischemic conditions.

Bioelectrical behaviour of hypoxic human neocortical tissue under the influence of nimodipine and dimethyl sulfoxide.

Nimodipine and dimethyl sulfoxide (DMSO) have been shown to affect electrophysiological responses in rodent brain tissue in an vitro model of hypoxia. In the present study, the same agents were now examined for their effects on human neocortical brain slices under repeated hypoxic conditions. DMSO (0.

Effects of methohexital on bioelectrical reactions in guinea pig hippocampal slices during hypoxia.

The barbiturate methohexital (42 and 140 micromol/l) was tested for an acute effect on anoxic depolarization (AD) and evoked potentials (EP) in hippocampal slices of guinea pigs exposed to repeated hypoxic conditions (n = 78). The dosages of methohexital resemble the range of plasma levels measured in patients with an intraoperative burst suppression electroencephalogram. Direct current potential and EP were recorded in the CA1 region.