High-dimensional single photon based quantum secure direct communication using time and phase mode degrees.

Quantum secure direct communication (QSDC) can guarantee security using the characteristics of quantum mechanics even when a message is directly transmitted through a quantum channel without using a secret key. However, the transmission rate of the QSDC is limited by the dead time of a single photon detector (SPD) as well as channel loss over the distance. To overcome this limited transmission rate, we propose a high-dimensional single photon-based QSDC protocol that applies two optical degrees of freedom: time and phase state. First, an N-dimensional time and phase state generation method that considers the dead time is proposed to minimize the measurement loss of a transmitted message. Second, among the two types of quantum states, the phase state with relatively low measurement efficiency is used only for eavesdropping detection, and the time state is used for sending messages with differential delay time bin-based encoding techniques. Lastly, we propose an efficient method for measuring N-dimensional time and phase-based quantum states and recovering classical bit information. This study performs security analysis against various attacks, and verifies the transmission rate improvement effect through simulation. The result indicates that our proposal can guarantee higher security and transmission rates compared to the conventional DL04 QSDC.

Factors affecting the length of stay in the emergency department for critically Ill patients transferred to regional emergency medical center.

AIM: To identify the factors affecting Emergency Department Length of Stay for transferred critically ill patients. BACKGROUND: The Length of Stay of the transferred patients is an important indicator of Emergency Department service quality; thus, understanding the factors affecting the Emergency Department Length of Stay of transferred critically ill patients is essential. METHODS: Using the electronic medical records of 968 transferred critically ill Emergency Department patients of a tertiary hospital in Korea, prediction models for Emergency Department Length of Stay were built using various machine learning algorithms. RESULTS: The logistic regression (AUROC 0.85) models showed the best performance, followed by random forest (AUROC 0.83) and Naive Bayes (AUROC 0.83). The logistic regression model indicated that fewer consultations, the highest acuity level, need for an emergency operation or angiography, need for ICU admission, severe emergency disease and fewer diagnoses were the statistically significant predictors for Emergency Department Length of Stay of 6 h or less. CONCLUSIONS: The transferred critically ill patients analysed in this study who required immediate or specialized care tended to receive needed care on time at the study site. IMPLICATIONS FOR NURSING MANAGEMENT: Understanding the factors affecting the Emergency Department Length of Stay of transferred critically ill patients is crucial for developing strategies to manage the nursing resource of Emergency Department successfully.

Knowledge and Practice Behaviors Regarding Urinary Incontinence Among Korean Healthcare Providers in Long-term Care Hospitals.

PURPOSE: The purpose of this study was to assess the current management status of patients with urological issues and to examine the level of knowledge and practice behaviors regarding urinary incontinence (UI) among Korean healthcare providers in long-term care hospitals. METHODS: This study used a cross-sectional descriptive design with a written questionnaire to assess knowledge and practice behaviors of 756 healthcare providers in 11 long-term care hospitals in Korean metropolitan areas. RESULTS: A total 42.6% of participants reported that more than 50% of patients had urologic issues, and that 68.1% of patients were regularly sent to urologists; no participants reported an on-site urologist in their facility. Participants identified collaboration with other hospitals and regular consultations by urologists as important factors in improving urologic care. Although the overall UI knowledge score was upper intermediate, a knowledge deficit was found for risk factors of UI. The knowledge level of physicians was significantly higher than that of other healthcare providers. Practice behaviors of nurses seemed to be better than those of other healthcare providers. CONCLUSIONS: Systematic collaboration between healthcare providers and urologic specialists, enhancing staff competence, and patient-tailored intervention should be recommended to improve quality of care for patients with urologic issues in long-term care hospitals.

Cytosine deaminase-producing human mesenchymal stem cells mediate an antitumor effect in a mouse xenograft model.

BACKGROUND AND AIM: Stem cell transplantation offers potential gene therapy for brain tumors. However, this approach has received little attention as a treatment for gastrointestinal tumors. In the present study, we explored the possibility of human bone marrow-derived mesenchymal stem cells (hMSC) producing cytosine deaminase (CD), followed by systemic 5-fluorocytosine (5-FC) administration, showing an antitumor effect on a mouse gastric cancer xenograft. METHODS: We first explored the ability of hMSC, coated with fluorescent dye, to migrate to human gastric cancer MKN45 cells in vitro and in vivo. We then used hMSC in which a gene expressed the prodrug-activating enzyme CD, which can convert the prodrug 5-FC into the cytotoxic agent 5-fluorouracil (5-FU), and further investigated the potential of these cells to deliver the CD gene and to reduce tumor growth in nude mice. The migratory capacity of hMSC was confirmed by an in vitro migration assay, as well as in an in vivo model of nude mice bearing subcutaneous tumors of MKN45 cells when hMSC were injected. RESULTS: The migration ability of hMSC towards MKN45 cells was confirmed by migration assay. Effective conversion of 5-FC to 5-FU by hMSC transfected with the CD gene (CD-hMSC) showed therapeutic anticancer potential in a MKN45 cell co-culture system, as confirmed by thin layer chromatography. Nude mice bearing MKN45 tumors were intravenously injected with CD-hMSC, followed by systemic 5-FC treatment (500 mg/kg/day) for 7 days. Tumor volumes and weights of mice injected with CD-hMSC decreased significantly after treatment with 5-FC. However, the 5-FC-treated group without CD-hMSC injection showed neither a decrease in tumor volume nor bodyweight loss. CONCLUSION: The CD-hMSC system showed anticancer therapeutic potential, and minimized the side-effects of 5-FU.

Complications with laparoscopically assisted gastrectomy: multivariate analysis of 300 consecutive cases.

BACKGROUND: Complications associated with laparoscopically assisted gastrectomy (LAG) are not significantly different from those associated with open gastrectomy. However, additional risks related to abdominal access, pneumoperitoneum, and special electrosurgical instruments result in an increased incidence of complications with LAG. This study analyzed the causes and risk factors linked to postoperative morbidity. METHODS: A retrospective review analyzed the data of 300 patients who underwent consecutive LAG for gastric cancer in our department from May 2003 to October 2006. Among the 300 patients, total gastrectomy was performed for 42 patients, distal gastrectomy for 258 patients, and proximal gastrectomy for 3 patients. The clinical and operative data obtained included body mass index, medical comorbidities, history of previous abdominal surgery, operative time, type of surgery, extent of lymph node dissection according to the Japanese Guideline, number of retrieved lymph nodes and lymph node metastases, additional operative procedure, depth of tumor invasion, and disease stage. The outcome data consisted of mortality, major morbidities, and postoperative hospital stay. The 300 cases were divided into two periods: 50 cases in the first period and 250 cases in the second period. RESULTS: Postoperative complications developed in 61 cases (20.3%), wound infection in 21 cases (7%), intraabdominal abscess in 3 cases (1%), bleeding in 12 cases (4%), stenosis in 13 cases (4.3%), leakage in 3 cases (1%), acute pancreatitis in 2 cases (0.7%), pulmonary complication in 4 cases (1.3%), renal complication in 4 cases (1.3%), and cardiac complication in 2 cases (0.7%). The 30-day mortality rate was 0.7% (n=2). Univariate analysis proved that gender, operative period, comorbidity, and operative times were important risk factors. Multivariate analysis proved that cormobidity and operative period were important risk factors. CONCLUSION: The data suggest that LAG can be performed with acceptable perioperative complication rates. The surgeon's experience and careful patient selection determined optimal patient outcomes.