Brain stimulation-on-a-chip: a neuromodulation platform for brain slices.

Electrical stimulation of ex vivo brain tissue slices has been a method used to understand mechanisms imparted by transcranial direct current stimulation (tDCS), but there are significant direct current electric field (dcEF) dosage and electrochemical by-product concerns in conventional experimental setups that may impact translational findings. Therefore, we developed an on-chip platform with fluidic, electrochemical, and magnetically-induced spatial control. Fluidically, the chamber geometrically confines precise dcEF delivery to the enclosed brain slice and allows for tissue recovery in order to monitor post-stimulation effects. Electrochemically, conducting hydrogel electrodes mitigate stimulation-induced faradaic reactions typical of commonly-used metal electrodes. Magnetically, we applied ferromagnetic substrates beneath the tissue and used an external permanent magnet to enable in situ rotational control in relation to the dcEF. By combining the microfluidic chamber with live-cell calcium imaging and electrophysiological recordings, we showcased the potential to study the acute and lasting effects of dcEFs with the potential of providing multi-session stimulation. This on-chip bioelectronic platform presents a modernized yet simple solution to electrically stimulate explanted tissue by offering more environmental control to users, which unlocks new opportunities to conduct thorough brain stimulation mechanistic investigations.

A Clinical Comparative Study of Rectus Sheath Closure Techniques in Emergency Exploratory Laparotomy: Evaluating "Far-Near-Near-Far" vs. Conventional Closure Approach.

BACKGROUND: Midline exploratory laparotomy is essential in emergency surgery, and effective closure of the abdominal wall is crucial for optimal healing and reduced complications. The far-near-near-far technique for rectus sheath closure has gained attention due to potential advantages over conventional closure due to the fact that even if one suture gives way it does not affect the nearby suture and the rectus sheath is still held in place. This study aims to compare these techniques in emergency exploratory laparotomy. METHODS: This single-center prospective observational study included all patients undergoing emergency exploratory laparotomy at a tertiary care hospital. Patients were categorized into two groups based on the closure technique used: conventional closure or far-near-near-far technique. Sociodemographic data and comorbidities were collected. Operative time, closure time, and postoperative complications were assessed. Statistical analysis was performed using IBM SPSS Statistics 22.0 (IBM Corp., Armonk, NY). RESULTS: The study included patients with a mean age of 42.14 years. Operative and closure times did not significantly differ between the groups. There was no significant difference in comorbidities between the two techniques. The incidence of wound infection, dehiscence, burst abdomen, incisional hernia, and sinus formation did not significantly differ between the groups. Late complications were also similar. CONCLUSION: The far-near-near-far technique for rectus sheath closure in emergency exploratory laparotomy showed comparable outcomes to conventional closure methods. No significant differences were found in operative time, closure time, or postoperative complications. This study contributes to the understanding of different closure techniques, allowing surgeons to make informed decisions.