Suppressed terahertz dynamics of water confined in nanometer gaps.

Nanoconfined waters exhibit low static permittivity mainly due to interfacial effects that span about one nanometer. The characteristic length scale may be much longer in the terahertz (THz) regime where long-range collective dynamics occur; however, the THz dynamics have been largely unexplored because of the lack of a robust platform. Here, we use metallic loop nanogaps to sharply enhance light-matter interactions and precisely measure real and imaginary THz refractive indices of nanoconfined water at gap widths ranging from 2 to 20 nanometers, spanning mostly interfacial waters all the way to quasi-bulk waters. We find that, in addition to the well-known interfacial effect, the confinement effect also contributes substantially to the decrease in the complex refractive indices of the nanoconfined water by cutting off low-energy vibrational modes, even at gap widths as large as 10 nanometers. Our findings provide valuable insights into the collective dynamics of water molecules which is crucial to understanding water-mediated processes.

Dexmedetomidine Ameliorates Sleep Deprivation-Induced Depressive Behaviors in Mice.

PURPOSE: Sleep deprivation induces depressive symptoms. Dexmedetomidine is a α2-adrenoreceptor agonist and this drug possesses sedative, anxiolytic, analgesic, and anesthetic-sparing effect. In this study, the action of dexmedetomidine on sleep deprivation-induced depressive behaviors was investigated using mice. METHODS: For the inducing of sleep deprivation, the mice were placed inside a water cage containing 15 platforms and filled with water up to 1 cm below the platform surface for 7 days. One day after sleep deprivation, dexmedetomidine at the respective dosage (0.5, 1, and 2 µg/kg) was intraperitoneally treated into the mice, one time per a day during 6 days. Then, forced swimming test and tail suspension test were conducted. Immunohistochemistry for tyrosine hydroxylase (TH), 5-hydroxytryptamine (5-HT; serotonin), tryptophan hydroxylase (TPH) and western blot for D1 dopamine receptor were also performed. RESULTS: Sleep deprivation increased the immobility latency in the forced swimming test and tail suspension test. The expressions of TPH, 5-HT, and D1 dopamine receptor were decreased, whereas, TH expression was increased by sleep deprivation. Dexmedetomidine decreased the immobility latency and increased the expressions of TPH, 5-HT, and D1 dopamine receptor, whereas, HT expression was decreased by dexmedetomidine treatment. CONCLUSION: In our results, dexmedetomidine alleviated sleep deprivation-induced depressive behaviors by increasing 5-HT synthesis and by decreasing dopamine production with up-regulation of D1 dopamine receptor.

Insertion of totally implantable central venous access devices by surgeons.

PURPOSE: The aim of this study is to evaluate the results for the insertion of totally implantable central venous access devices (TICVADs) by surgeons. METHODS: Total 397 patients, in whom TICVADs had been inserted for intravenous chemotherapy between September 2008 and June 2014, were pooled. This procedure was performed under local anesthesia in an operation room. The insertion site for the TICVAD was mainly in the right-side subclavian vein. In the case of breast cancer patients, the subclavian vein opposite the surgical site was used for insertion. RESULTS: The 397 patients included 73 males and 324 females. Primary malignant tumors were mainly colorectal and breast cancer. The mean operation time was 54 minutes (18-276 minutes). Operation-related complications occurred in 33 cases (8.3%). Early complications developed in 15 cases with catheter malposition and puncture failure. Late complications, which developed after 24 hours, included inflammation in 6 cases, skin necrosis in 6 cases, hematoma in 3 cases, port malfunction in 1 case, port migration in 1 case, and intractable pain at the port site in 1 case. CONCLUSION: Insertion of a TICVAD under local anesthesia by a surgeon is a relatively safe procedure. Meticulous undermining of the skin and carefully managing the TICVAD could minimize complications.