Chiral orbital-angular-momentum in the surface states of Bi2Se3

Locking of the spin of a quasi-particle to its momentum in split bands of on the surfaces of metals and topological insulators (TIs) is understood in terms of Rashba effect where a free electron in the surface states feels an effective magnetic field. On the other hand, the orbital part of the angular momentum (OAM) is usually neglected. We performed angle resolved photoemission experiments with circularly polarized lights and first principles density functional calculation with spin-orbit coupling on a TI, Bi2Se3, to study the local OAM of the surface states. We show from the results that OAM in the surface states of Bi2Se3 is significant and locked to the electron momentum in opposite direction to the spin, forming chiral OAM states. Our finding opens a new possibility to have strong light-induced spin-polarized current in the surface states.Comment: 5 pages, 4 figures, 1 tabl

Prevalence of Human Papilloma Virus Infections and Cervical Cytological Abnormalities among Korean Women with Systemic Lupus Erythematosus

We performed a multicenter cross-sectional study of 134 sexually active systemic lupus erythematosus (SLE) patients to investigate the prevalence of and risk factors for high risk human papilloma virus (HPV) infection and cervical cytological abnormalities among Korean women with SLE. In this multicenter cross-sectional study, HPV testing and routine cervical cytologic examination was performed. HPV was typed using a hybrid method or the polymerase chain reaction. Data on 4,595 healthy women were used for comparison. SLE patients had greater prevalence of high-risk HPV infection (24.6% vs. 7.9%, P<0.001, odds ratio 3.8, 95% confidence interval 2.5-5.7) and of abnormal cervical cytology (16.4 vs. 2.8%, P<0.001, OR 4.4, 95% CI 2.5-7.8) compared with controls. SLE itself was identified as independent risk factors for high risk HPV infection among Korean women (OR 3.8, 95% CI 2.5-5.7) along with ≥2 sexual partners (OR 8.5, 95% CI 1.2-61.6), and Pap smear abnormalities (OR 97.3, 95% CI 6.5-1,456.7). High-risk HPV infection and cervical cytological abnormalities were more common among Korean women with SLE than controls. SLE itself may be a risk factor for HPV infection among Korean women, suggesting the importance of close monitoring of HPV infections and abnormal Pap smears in SLE patients

Non-specific Defensive Factors of the Pacific Oyster Crassostrea gigas against Infection with Marteilioides chungmuensis: A Flow-Cytometric Study

In order to assess changes in the activity of immunecompetency present in Crassostrea gigas infected with Marteilioides chungmuensis (Protozoa), the total hemocyte counts (THC), hemocyte populations, hemocyte viability, and phagocytosis rate were measured in oysters using flow cytometry. THC were increased significantly in oysters infected with M. chungmuensis relative to the healthy appearing oysters (HAO) (P<0.05). Among the total hemocyte composition, granulocyte levels were significantly increased in infected oysters as compared with HAO (P<0.05). In addition, the hyalinocyte was reduced significantly (P<0.05). The hemocyte viability did not differ between infected oysters and HAO. However, the phagocytosis rate was significantly higher in infected oysters relative to HAO (P<0.05). The measurement of alterations in the activity of immunecompetency in oysters, which was conducted via flow cytometry in this study, might be a useful biomarker of the defense system for evaluating the effects of ovarian parasites of C. gigas

Results from Over One Year of Follow-Up for Absorbable Mesh Insertion in Partial Mastectomy

∙ The authors have no financial conflicts of interest. © Copyright: Yonsei University College of Medicine 2011 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial Licens

Inflammatory and Tumor Stimulating Responses after Laparoscopic Sigmoidectomy

PURPOSE: Laparoscopic colectomy has clinical benefits such as short hospital stay, less postoperative pain, and early return of bowel function. However, objective evidence of its immunologic and oncologic benefits is scarce. We compared functional recovery after open versus laparoscopic sigmoidectomy and investigated the effect of open versus laparoscopic surgery on acute inflammation as well as tumor stimulation. MATERIALS AND METHODS: A total of 57 patients who were diagnosed with sigmoid colon cancer were randomized for elective conventional or laparoscopically assisted sigmoidectomy. Serum samples were obtained preoperatively and on postoperative day 1. C-reactive protein (CRP) and interleukin-6 (IL-6) were measured as inflammation markers, and vascular endothelial growth factor (VEGF) and insulin-like growth factor binding protein-3 (IGFBP-3) were used as tumor stimulation factors. Clinical parameters and serum markers were compared. RESULTS: Postoperative hospital stay (p=0.031), the first day of gas out (p=0.016), and the first day of soft diet (p<0.001) were significantly shorter for the laparoscopic surgery group than the open surgery group. The levels of CRP, IL-6, and VEGF rose significantly, and the concentration of IGFBP-3 fell significantly after both open and laparoscopic surgery. However, there were no significant differences in the preoperative and postoperative levels of CRP, IL-6, VEGF, and IGFBP-3 between the two groups. CONCLUSION: Our data suggest that both open and laparoscopic surgeries are accompanied by significant changes in IL-6, CRP, IGFBP-3, and VEGF levels. Acute inflammation markers and tumor stimulating factors may not reflect clinical benefits of laparoscopic surgery.ope

Etiology of Invasive Bacterial Infections in Immunocompetent Children in Korea (1996-2005): A Retrospective Multicenter Study

The purpose of this study was to identify the major etiological agents responsible for invasive bacterial infections in immunocompetent Korean children. We retrospectively surveyed invasive bacterial infections in immunocompetent children caused by eight major pediatric bacteria, namely Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pyogenes, Listeria monocytogenes, and Salmonella species that were diagnosed at 18 university hospitals from 1996 to 2005. A total of 768 cases were identified. S. agalactiae (48.1%) and S. aureus (37.2%) were the most common pathogens in infants younger than 3 months. S. agalactiae was a common cause of meningitis (73.0%), bacteremia without localization (34.0%), and arthritis (50%) in this age group. S. pneumoniae (45.3%) and H. influenzae (20.4%) were common in children aged 3 months to 5 yr. S. pneumoniae was a common cause of meningitis (41.6%), bacteremia without localization (40.0%), and bacteremic pneumonia (74.1%) in this age group. S. aureus (50.6%), Salmonella species (16.9%), and S. pneumoniae (16.3%) were common in older children. A significant decline in H. influenzae infections over the last 10 yr was noted. S. agalactiae, S. pneumoniae, and S. aureus are important pathogens responsible for invasive bacterial infections in Korean children