Investigation of Program Efficiency Overshoot in 3D Vertical Channel NAND Flash with Randomly Distributed Traps.

The incremental step pulse programming slope (ISPP) with random variation was investigated by measuring numerous three-dimensional (3D) NAND flash memory cells with a vertical nanowire channel. We stored multiple bits in a cell with the ISPP scheme and read each cell pulse by pulse. The excessive tunneling from the channel to the storage layer determines the program efficiency overshoot. Then, a broadening of the threshold voltage distribution was observed due to the abnormal program cells. To analyze the randomly varying abnormal program behavior itself, we distinguished between the read variation and over-programming in measurements. Using a 3D Monte-Carlo simulation, which is a probabilistic approach to solve randomness, we clarified the physical origins of over-programming that strongly influence the abnormal program cells in program step voltage, and randomly distributed the trap site in the nitride of a nanoscale 3D NAND string. These causes have concurrent effects, but we divided and analyzed them quantitatively. Our results reveal the origins of the variation and the overshoot in the ISPP, widening the threshold voltage distribution with traps randomly located at the nanoscale. The findings can enhance understanding of random over-programming and help mitigate the most problematic programming obstacles for multiple-bit techniques.

Optimal Energetic-Trap Distribution of Nano-Scaled Charge Trap Nitride for Wider Vth Window in 3D NAND Flash Using a Machine-Learning Method.

A machine-learning (ML) technique was used to optimize the energetic-trap distributions of nano-scaled charge trap nitride (CTN) in 3D NAND Flash to widen the threshold voltage (Vth) window, which is crucial for NAND operation. The energetic-trap distribution is a critical material property of the CTN that affects the Vth window between the erase and program Vth. An artificial neural network (ANN) was used to model the relationship between the energetic-trap distributions as an input parameter and the Vth window as an output parameter. A well-trained ANN was used with the gradient-descent method to determine the specific inputs that maximize the outputs. The trap densities (NTD and NTA) and their standard deviations (σTD and σTA) were found to most strongly impact the Vth window. As they increased, the Vth window increased because of the availability of a larger number of trap sites. Finally, when the ML-optimized energetic-trap distributions were simulated, the Vth window increased by 49% compared with the experimental value under the same bias condition. Therefore, the developed ML technique can be applied to optimize cell transistor processes by determining the material properties of the CTN in 3D NAND Flash.

Transport Dynamics of MtrD: An RND Multidrug Efflux Pump from Neisseria gonorrhoeae.

The MtrCDE system confers multidrug resistance to Neisseria gonorrhoeae, the causative agent of gonorrhea. Using free and directed molecular dynamics (MD) simulations, we analyzed the interactions between MtrD and azithromycin, a transport substrate of MtrD, and a last-resort clinical treatment for multidrug-resistant gonorrhea. We then simulated the interactions between MtrD and streptomycin, an apparent nonsubstrate of MtrD. Using known conformations of MtrD homologues, we simulated a potential dynamic transport cycle of MtrD using targeted MD techniques (TMD), and we noted that forces were not applied to ligands of interest. In these TMD simulations, we observed the transport of azithromycin and the rejection of streptomycin. In an unbiased, long-time scale simulation of AZY-bound MtrD, we observed the spontaneous diffusion of azithromycin through the periplasmic cleft. Our simulations show how the peristaltic motions of the periplasmic cleft facilitate the transport of substrates by MtrD. Our data also suggest that multiple transport pathways for macrolides may exist within the periplasmic cleft of MtrD.

Comparison of palonosetron with combined palonosetron and midazolam for preventing postoperative nausea and vomiting after laparoscopic cholecystectomy.

BACKGROUND: Postoperative nausea and vomiting (PONV) is an undesirable complication in patients undergoing general anesthesia. Combination therapy via different mechanisms of action for antiemetic prophylaxis has been warranted for effective treatment of PONV. This study was designed to compare the prophylactic antiemetic effect between midazolam combined with palonosetron (group MP) and palonosetron alone (group P) after laparoscopic cholecystectomy surgeries. METHODS: A prospective randomized controlled trial was investigated in non-smoking female. Eighty-eight patients were randomly divided into 2 groups with 44 patients each. Group MP received 0.05 mg/kg of midazolam intravenously before induction of anesthesia whereas group P received the same volume of normal saline. Immediately after anesthetic induction, 0.075 mg of palonosetron was administered to both the groups. The incidence and severity of PONV were assessed during 2 time intervals (0-2 hours, 2-24 hours), postoperatively. RESULTS: The incidence of PONV during 24 hours after surgery was lower in group MP as compared to group P. There was also a significant difference in the use of rescue antiemetics. The severity of nausea was significantly lower in group MP as compared to group P, in the initial 2 hours after surgery. The incidence of side effects was similar between the 2 groups. CONCLUSION: In the prevention of PONV, midazolam combined with palonosetron, administered during induction of anesthesia was more effective as compared to palonosetron alone.

Acute compartment syndrome due to extravasation of peripheral intravenous blood transfusion.

Extravasation is an inadvertent injection or leakage of fluid and drugs in the extravascular or subcutaneous space. The extravasation by massive transfused blood results in the elevation of intra-compartmental pressures. Severely increased pressure may lead to acute compartment syndrome (ACS). A 50-year-old man underwent craniectomy for traumatic subdural hemorrhage of the brain. During intraoperative periods, the blood components were transfused by rapid transfusion device and manual pressurized pumping through the central and peripheral lines because of hemorrhagic hypovolemic shock. Approximately 30 minutes after transfusion, we found a hardened right low leg that was obscured by the surgical drape. Immediately, fasciotomy was performed to release all four compartments. The early recognition and treatment of ACS were important factors contributing to anatomical structure salvage and preservation of function. Anesthesia providers should check the site of the insertion of the intravenous catheter, especially while pressurized massive transfusion via the peripheral intravenous catheter.

Comparative study of the quality characteristics of defatted soy flour treated by supercritical carbon dioxide and organic solvent.

Defatted soy flour is a potential source of food protein, amino acids, ash and isoflavones. The supercritical carbon dioxide (SC-CO2) and a traditional organic solvent extraction methods were used to remove fat from soy flour, and the quality characteristics of a control soy flour (CSF), defatted soy flour by SC-CO2 (DSFSC-CO2) and defatted soy flour by an organic solvent (DSF-OS) were compared. The SC-CO2 process was carried out at a constant temperature of 45 °C, and a pressure of 40 MPa for 3 h with a CO2 flow rate of 30 g/min. The DSFSC-CO2 had significantly higher protein, ash, and amino acids content than CSF and DSF-OS. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis demonstrated that CSF and DSFSC-CO2 had protein bands of similar intensity and area that indicated no denaturation of protein, whereas DSF-OS showed diffuse bands or no bands due to protein denaturation. In addition to higher nutritional value and protein contents, DSFSC-CO2 showed superior functional properties in terms of total soluble solids content, water and oil absorption, emulsifying and foaming capacity. The SC-CO2 method offers a nutritionally and environmentally friendly alternative extraction processing approach for the removal of oil from high-protein food sources. It has a great potential for producing high-protein fat-free, and low-calorie content diet than the traditional organic solvent extraction method.