Degeneracy of Landau Level and Quantum Group SL_q(2)

We show that there is a kind of quantum group symmetry $sl_{q}(2)$ in the usual Landau problem and it is this quantum group symmetry that governs the degeneracy of Landau levels. We find that under the periodic boundary condition, the degree of degeneracy of Landau levels is finite, and it just equals the dimension of the irreducible cyclic representation of the quantum group $sl_{q}(2)$.Comment: 10 pages, Preprint ( reprint ) of Nankai Institute of Mathematics. For hard copy, write to Prof. Mo-lin GE, Director of Nankai Institute of Mathematics. Do not send emails to this computer accoun

Effects of <i>ELOVL4</i> gene overexpress on the synthesis efficiency of n3 and n6 very long chain polyunsaturated fatty acids

AIM:To compare the synthesis efficiency of n3 and n6 very long chain polyunsaturated fatty acid(VLC-PUFA)by overexpressing ELOVL4 protein, providing guidance for treating Stargardt-like macular dystrophy(STGD3).<p>METHODS:To establish recombinant adenovirus with the ELOVL4 protein and green fluorescent protein, transferred into cultured PC12 cells. The cells were divided into 3 groups: PC12, PC12+Ad-<i>GFP</i> and PC12+Ad- <i>ELOVL4</i>, former two groups serve as controls. <i>ELOVL4</i> gene expression was quantified by qRT-PCRs. ELOVL4 protein was analyzed by Western-Blot(WB). The transduced cells were treated with both EPA and AA(1:1). After 48h of incubation, cells were collected, total lipids extracted and fatty acid methyl esters prepared and analyzed by gas chromatography-mass spectrometry(GC-MS). <p>RESULTS: When supplemented together, 20:5n3(EPA)and 20:4n6(AA)were efficiently taken up at almost the same amounts in the PC12 cells regardless of ELOVL4 expression. The ELOVL4-expressing cells elongated both EPA and AA to a series of n3 and n6 VLC-PUFAs. From 20:5n3/EPA, 34:5n3 and 36:5n3 account for 0.71% and 1.6%, respectively. From 20:4n6/DHA, 34:4n6 and 36:4n6 were only 0.46% and 0.61%, respectively. The total relative mol% of n3 VLC-PUFAs synthesized from EPA was almost two times that of n6 VLC-PUFAs synthesized from AA.<p>CONCLUSION: <i>ELOVL4</i> protein preferentially elongates n3 PUFA to VLC-PUFAs over n6 PUFA. Dietary supplementation of appropriate n3/n6 PUFAs may provide STGD3 patients with some therapeutic benefits

A genuine four-partite entangled state

In a recent paper, a genuine four-partite entangled state is proposed [Y. Yeo and W. K. Chua, Phys. Rev. Lett. 96, 060502 (2006)], which has been found to have many interesting entanglement properties. We show this state is locally equivalent to some graph states.Comment: submitte

Simultaneous Cranioplasty and Subdural-Peritoneal Shunting for Contralateral Symptomatic Subdural Hygroma following Decompressive Craniectomy

Background. Contralateral subdural hygroma caused by decompressive craniectomy tends to combine with external cerebral herniation, causing neurological deficits. Material and Methods. Nine patients who underwent one-stage, simultaneous cranioplasty and contralateral subdural-peritoneal shunting were included in this study. Clinical outcome was assessed by Glasgow Outcome Scale as well as Glasgow Coma Scale, muscle power scoring system, and complications. Results. Postoperative computed tomography scans demonstrated completely resolved subdural hygroma and reversed midline shifts, indicating excellent outcome. Among these 9 patients, 4 patients (44%) had improved GOS following the proposed surgery. Four out of 4 patients with lethargy became alert and orientated following surgical intervention. Muscle strength improved significantly 5 months after surgery in 7 out of 7 patients with weakness. Two out of 9 patients presented with drowsiness due to hydrocephalus at an average time of 65 days after surgery. Double gradient shunting is useful to eliminate the respective hydrocephalus and contralateral subdural hygroma. Conclusion. The described surgical technique is effective in treating symptomatic contralateral subdural hygroma following decompressive craniectomy and is associated with an excellent structural and functional outcome. However, subdural-peritoneal shunting plus cranioplasty thoroughly resolves the subdural hygroma collection, which might deteriorate the cerebrospinal fluid circulation, leading to hydrocephalus

By protecting against cutaneous inflammation, epidermal pigmentation provided an additional advantage for ancestral humans.

Pigmentation evolved in ancestral humans to protect against toxic, ultraviolet B irradiation, but the question remains: "what is being protected?" Because humans with dark pigmentation display a suite of superior epidermal functions in comparison with their more lightly pigmented counterparts, we hypothesized and provided evidence that dark pigmentation evolved in Africa to support cutaneous function. Because our prior clinical studies also showed that a restoration of a competent barrier dampens cutaneous inflammation, we hypothesized that resistance to inflammation could have provided pigmented hominins with yet another, important evolutionary benefit. We addressed this issue here in two closely related strains of hairless mice, endowed with either moderate (Skh2/J) or absent (Skh1) pigmentation. In these models, we showed that (a) pigmented mice display a markedly reduced propensity to develop inflammation after challenges with either a topical irritant or allergen in comparison with their nonpigmented counterparts; (b) visible and histologic evidence of inflammation was paralleled by reduced levels of pro-inflammatory cytokines (i.e., IL-1α and INFα); (c) because depigmentation of Skh2/J mouse skin enhanced both visible inflammation and pro-inflammatory cytokine levels after comparable pro-inflammatory challenges, the reduced propensity to develop inflammation was directly linked to the presence of pigmentation; and (d) furthermore, in accordance with our prior work showing that pigment production endows benefits by reducing the surface pH of skin, acidification of albino (Skh1) mouse skin also protected against inflammation, and equalized cytokine levels to those found in pigmented skin. In summary, pigmentation yields a reduced propensity to develop inflammation, consistent with our hypothesis that dark pigmentation evolved in ancestral humans to provide a suite of barrier-linked benefits that now include resistance to inflammation

Role of glucose in the repair of cell membrane damage during squeeze distortion of erythrocytes in microfluidic capillaries

The rapid development of portable precision detection methods and the crisis of insufficient blood supply worldwide has led scientists to study mechanical visualization features beyond the biochemical properties of erythrocytes. Combined evaluation of currently known biochemical biomarkers and mechanical morphological biomarkers will become the mainstream of single-cell detection in the future. To explore the mechanical morphology of erythrocytes, a microfluidic capillary system was constructedin vitro, with flow velocity and glucose concentration as the main variables, and the morphology and ability of erythrocytes to recover from deformation as the main objects of analysis. We showed the mechanical distortion of erythrocytes under various experimental conditions. Our results showed that glucose plays important roles in improving the ability of erythrocytes to recover from deformation and in repairing the damage caused to the cell membrane during the repeated squeeze process. These protective effects were also confirmed inin vivoexperiments. Our results provide visual detection markers for single-cell chips and may be useful for future studies in cell aging

Predictors of intra-abdominal coagulopathic hemorrhage after living donor liver transplantation

AbstractBackgroundResults of preoperative conventional coagulation assays are a poor predictor of hemorrhage after liver transplantation. In this study, we evaluated the factors that are predictive of intra-abdominal coagulopathic hemorrhage after living donor liver transplantation surgery.MethodsDuring the period from January 2009 to December 2012, 118 adults underwent living donor liver transplantation (LDLT) in our institution. Of those patients, 18 (15.3%) developed intra-abdominal coagulopathic hemorrhage (n = 7) or hemorrhage due to non-coagulopathic causes (n = 11) that required emergency medical, radiological, or surgical intervention within the first month after LDLT. Possible predictors of postoperative coagulopathic hemorrhage included donor-related factors, age, body mass index, MELD score, INR value, intra-operative blood transfusion, graft/recipient weight ratio, anhepatic phase, cold ischemia time, operative time, APACHE II score, onset of re-bleeding, and hemoglobin levels during rebleeding episodes.ResultsThere were no differences in any of the variables between the two groups (coagulopathic and noncoagulopathic hemorrhage) except for cold ischemia time. We found that cold ischemia time was significantly longer in patients with postoperative coagulopathic hemorrhage (160.50 ± 45.02 min) than in patients with hemorrhage due to non-coagulopathic causes (113.55 ± 29.31 min; P = 0.027).ConclusionProlonged cold ischemia time is associated with postoperative intra-abdominal coagulopathic hemorrhage in patients after LDLT. It is, therefore, necessary to shorten the cold ischemia time in order to reduce the risk of postoperative intra-abdominal hemorrhage due to coagulopathic causes

An optimized computational model for multi-community-cloud social collaboration

PublishedCommunity Cloud Computing is an emerging and promising computing model for a specific community with common concerns, such as security, compliance and jurisdiction. It utilizes the spare resources of networked computers to provide the facilities so that the community gains services from the cloud. The effective collaboration among the community clouds offers a powerful computing capacity for complex tasks containing the subtasks that need data exchange. Selecting the best group of community clouds that are the most economy-efficient, communication-efficient, secured, and trusted to accomplish a complex task is very challenging. To address this problem, we first formulate a computational model for multi-community-cloud collaboration, namely MG3. The proposed model is then optimized from four aspects: minimizing the sum of access cost and monetary cost, maximizing the security-level agreement and trust among the community clouds. Furthermore, an efficient and comprehensive selection algorithm is devised to extract the best group of community clouds in MG3. Finally, the extensive simulation experiments and performance analysis of the proposed algorithm are conducted. The results demonstrate that the proposed algorithm outperforms the minimal set coverings based algorithm and the random algorithm. Moreover, the proposed comprehensive community clouds selection algorithm can guarantee good global performance in terms of access cost, monetary cost, security level and trust between user and community clouds