Nearly Massless Electrons in the Silicon Interface with a Metal Film

We demonstrate the realization of nearly massless electrons in the most widely used device material, silicon, at the interface with a metal film. Using angle-resolved photoemission, we found that the surface band of a monolayer lead film drives a hole band of the Si inversion layer formed at the interface with the film to have nearly linear dispersion with an effective mass about 20 times lighter than bulk Si and comparable to graphene. The reduction of mass can be accounted for by repulsive interaction between neighboring bands of the metal film and Si substrate. Our result suggests a promising way to take advantage of massless carriers in silicon-based thin-film devices, which can also be applied for various other semiconductor devices.Comment: 4 pages, 4 figures, accepted for publication in Physical Review Letter

Brown fat organogenesis and maintenance requires AKT1 and AKT2

Objective: Understanding the signaling mechanisms that control brown adipose tissue (BAT) development is relevant to understanding energy homeostasis and obesity. The AKT kinases are insulin effectors with critical in vivo functions in adipocytes; however, their role in adipocyte development remains poorly understood. The goal of this study was to investigate AKT function in BAT development. Methods: We conditionally deleted Akt1 and Akt2 either individually or together with Myf5-Cre, which targets early mesenchymal precursors that give rise to brown adipocytes. Because Myf5-Cre also targets skeletal muscle and some white adipocyte lineages, comparisons were made between AKT function in BAT versus white adipose tissue (WAT) and muscle development. We also deleted both Akt1 and Akt2 in mature brown adipocytes with Ucp1-Cre or Ucp1-CreER to investigate AKT1/2 signaling in BAT maintenance. Results: AKT1 and AKT2 are individually dispensable in Myf5-Cre lineages in vivo for establishing brown and white adipocyte precursor cell pools and for their ability to differentiate (i.e. induce PPARγ). AKT1 and AKT2 are also dispensable for skeletal muscle development, and AKT3 does not compensate in either the adipocyte or muscle lineages. In contrast, AKT2 is required for adipocyte lipid filling and efficient downstream AKT substrate phosphorylation. Mice in which both Akt1 and Akt2 are deleted with Myf5-Cre lack BAT but have normal muscle mass, and doubly deleting Akt1 and Akt2 in mature brown adipocytes, either congenitally (with Ucp1-Cre), or inducibly in older mice (with Ucp1-CreER), also ablates BAT. Mechanistically, AKT signaling promotes adipogenesis in part by stimulating ChREBP activity. Conclusions: AKT signaling is required in vivo for BAT development but dispensable for skeletal muscle development. AKT1 and AKT2 have both overlapping and distinct functions in BAT development with AKT2 being the most critical individual isoform. AKT1 and AKT2 also have distinct and complementary functions in BAT maintenance.Fil: Sanchez Gurmaches, Joan. University Of Cincinnati College Of Medicine; Estados Unidos. University of Massachusetts Medical School; Estados UnidosFil: Martinez Calejman, Camila. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Jung, Su Myung. University Of Massachusetts Medical School; Estados UnidosFil: Li, Huawei. University Of Massachusetts Medical School; Estados UnidosFil: Guertin, David A.. University Of Massachusetts Medical School; Estados Unido

Characterization of subcellular localization of eukaryotic clamp loader/unloader and its regulatory mechanism

Proliferating cell nuclear antigen (PCNA) plays a critical role as a processivity clamp for eukaryotic DNA polymerases and a binding platform for many DNA replication and repair proteins. The enzymatic activities of PCNA loading and unloading have been studied extensively in vitro. However, the subcellular locations of PCNA loaders, replication complex C (RFC) and CTF18-RFC-like-complex (RLC), and PCNA unloader ATAD5-RLC remain elusive, and the role of their subunits RFC2-5 is unknown. Here we used protein fractionation to determine the subcellular localization of RFC and RLCs and affinity purification to find molecular requirements for the newly defined location. All RFC/RLC proteins were detected in the nuclease-resistant pellet fraction. RFC1 and ATAD5 were not detected in the non-ionic detergent-soluble and nuclease-susceptible chromatin fractions, independent of cell cycle or exogenous DNA damage. We found that small RFC proteins contribute to maintaining protein levels of the RFC/RLCs. RFC1, ATAD5, and RFC4 co-immunoprecipitated with lamina-associated polypeptide 2 (LAP2) alpha which regulates intranuclear lamin A/C. LAP2 alpha knockout consistently reduced detection of RFC/RLCs in the pellet fraction, while marginally affecting total protein levels. Our findings strongly suggest that PCNA-mediated DNA transaction occurs through regulatory machinery associated with nuclear structures, such as the nuclear matrix

BROADCAST ENCRYPTION π\pi

We propose a new broadcast encryption scheme $\pi$ based on the idea of `one key per each punctured interval\u27. Let $N$ and $r$ be the numbers of total users and revoked users, respectively. In our scheme with $p$-punctured $c$-intervals, the transmission overhead is asymptotically {\normalsize$\frac r{p+1}$} as $r$ grows. We also introduce two variants of our scheme to improve the efficiency for small $r$. Our scheme is very flexible with two parameters $p$ and $c$. We may take $p$ as large as possible if a user device allows a large key storage, and set $c$ as small as possible if the storage size and the computing power is limited. Our scheme also possesses another remarkable feature that any number of new users can join at any time without key refreshment, which is not possible in other known practical schemes

Molecular epidemiology of Japanese encephalitis virus circulating in South Korea, 1983-2005

We sequenced the envelope (E) gene of 17 strains of the Japanese encephalitis virus (JEV) isolated in South Korea in 1983-2005 and compared the sequences with those from previously reported strains. Our results show the remarkable genetic stability of the E gene sequence in Korean JEV strains. Five pairs of E gene sequences from 10 Korean strains were identical, despite geographical differences and a maximum five-year time span. Sequence comparisons with other Asian strains revealed that the Korean strains are closely related to those from China, Japan, and Vietnam. Genotype 3 strains were predominant in Korea before 1993, when genotype 1 strain K93A07 was first isolated. The two genotypes were detected simultaneously in 1994 but since then, only genotype 1 has been isolated in South Korea. Thus, the genotype change occurred according to the year of isolation rather than the geographical origin

A Rare Case of Recurrent Myoid Hamartoma Mimicking Malignancy: Imaging Appearances

Myoid hamartoma is an uncommon type of breast hamartoma and its recurrence is very rare. We report the imaging appearance of an unusual case of recurrent myoid hamartoma of the breast mimicking malignancy in a 43-year-old woman. Although the mammographic and ultrasonographic findings have long been described in the literature, MR finding with a dynamic study has not, to the best of our knowledge, been reported previously

Solitary Small Bowel Metastasis from Breast Cancer

The common sites of metastasis of breast cancer are bone, lung, and liver, but gastrointestinal metastasis from breast cancer is rare. We experienced a case of solitary ileal metastasis from breast cancer. A 45-years-old woman presented with melena for several weeks. She showed no other abdominal symptoms. Colonoscopy findings showed an ulcerative mucosal lesion in the terminal ileum, and biopsy was performed. Pathologic examination revealed metastatic carcinoma, originated from breast. The tumor cells were positive for estrogen receptor and negative for Cdx-2. She had had a previous medical history of bilateral breast cancer and undergone breast conserving surgery with sentinel lymph node biopsy for both breasts. The torso positron emission tomography scan at 19 months after surgery showed mildly increased uptake in the terminal ileum which was considered as inflammation. Finally, she was diagnosed with solitary ileal metastasis from breast cancer at 22 months after surgery

Comparison of the effectiveness of extensor muscle strengthening exercise by itself, exercise with polydeoxyribonucleotide injection, and exercise with extracorporeal shockwave therapy in lateral epicondylitis: a randomized controlled trial

Background Extensor muscle strengthening exercises with counterforce braces (EX) is a conventional conservative treatment for lateral epicondylitis (LE) of the elbow. In addition, polydeoxyribonucleotide (PDRN) or extracorporeal shockwave therapy (ESWT) has been recently used for LE. Methods Sixty-three patients with chronic LE participated in this study and randomly allocated in three groups (G1: EX, G2: EX+PDRN injection, and G3: EX+ESWT). All of the three groups were taught to perform EX at the first out-patient department (OPD) visit. Group 2 was injected with 3 mL PDRN (5.625 mg/3 mL), while group 3 received ESWT at the first OPD visit. Visual analog scale pain score, Mayo elbow performance score (MEPS), and ultrasonographic examination were checked before, 6 weeks, and 12 weeks after the treatments. Results Overall functional scores and ultrasonographic findings in all three groups improved after treatment. The mean MEPS in group 2 improved more than groups 1 and 3 at 6 weeks (G1, 56.9>62.4; G2, 54.3>65.0; G3, 55.7>62.6), and more than group 1 at 12 weeks (G1, 56.9>67.9; G2, 54.3>73.6). The mean common extensor tendon depth (CETD) on ultrasonography in group 2 increased more than groups 1 and 3 at 6 and 12 weeks (6 weeks: G1, 0.385>0.386; G2, 0.332>0.392; G3, 0.334>0.357; 12 weeks: G1, 0.385>0.409; G2, 0.332>0.438; G3, 0.334>0.405 [cm]). Conclusions PDRN injections combined with EX exhibited a greater improvement in mean MEPS and mean CETD compared to EX only or EX combined with ESWT for LE within the 12 weeks follow-up

Clinical Presentation and Management of Jugular Foramen Paraganglioma

ObjectivesJugular foramen paraganglioma is a locally invasive, benign tumor, which grow slowly and causes various symptoms such as pulsatile tinnitus and low cranial nerve palsy. Complete surgical resection is regarded as the ideal management of these tumors. The goal of this study is to identify the clinical characteristics and most effective surgical approach for jugular foramen paraganglioma.MethodsRetrospective analysis of 9 jugular foramen paraganglioma patients who underwent surgical resection between 1986 and 2005 was performed. Clinical records were reviewed for analysis of initial clinical symptoms and signs, audiological examinations, neurological deficits, radiological features, surgical approaches, extent of resection, treatment outcomes and complications.ResultsMost common initial symptom was hoarseness, followed by pulsatile tinnitus. Seven out of 9 patients had at least one low cranial nerve palsy. Seven patients were classified as Fisch Type C tumor and remaining 2 as Fisch Type D tumor on radiologic examination. Total of 11 operations took place in 9 patients. Total resection was achieved in 6 cases, when partial resection was done in 3 cases. Two patients with partial resection received gamma knife radiosurgery (GKS), when remaining 1 case received both GKS and two times of revision operation. No mortality was encountered and there were few postoperative complications.ConclusionNeurologic examination of low cranial nerve palsy is crucial since most patients had at least one low cranial nerve palsy. All tumors were detected in advanced stage due to slow growing nature and lack of symptom. Angiography with embolization is crucial for successful tumor removal without massive bleeding. Infratemporal fossa approach can be considered as a safe, satisfactory approach for removal of jugular foramen paragangliomas. In tumors with intracranial extension, combined approach is recommended in that it provides better surgical view and can maintain the compliance of the patients