30 research outputs found
Space of nilpotent orbits and extension of period maps (I): The weight 3 Calabi-Yau types
In Kato-Nakayama-Usui's theory, a certain space of nilpotent orbits can be
constructed and serve as a completion of a given period map. This can be
regarded as a generalization of Mumford's toroidal compactification for locally
symmetric varieties.
Kato-Nakayama-Usui's construction requires the existence of a weak fan, which
is not known in general for non-classical cases. In this paper, we show after
some slight modifications, such weak fans exist for a large class of period
maps of weight 3 Calabi-Yau type. In particular, for these cases a
Kato-Nakayama-Usui type completion can be constructed.Comment: 50 pages. Comments welcome. The first paper in a series. Some
structural changes and corrections in v
Completion of two-parameter period maps by nilpotent orbits
We show that every two-parameter period map admits a Kato--Nakayama--Usui
completion to a morphism of log manifolds
Hodge Theoretic Compactification of Period Maps
In this article, we review some aspects regarding Hodge-theoretic completion and boundarybehavior of period maps. First, we recall some classical results on compactification of classical period domains e.g. Baily-Borel, Ash-Mumford-Rapoport-Thai. The works produced by Kato-Usui aims at generalizing Mumford’s toroidal compactification to nonclassical period domain, which depends on construction of a strongly compatible fan. We prove such a fan can not exists universally, but for a single geometric variation of Hodge structure. We proceed such a construction on a 2-parameter geometric variation coming from Hosono-Takagi’s family of Calabi-Yau threefolds of type (1, 2, 2, 1). Moreover, we briefly review the concept of eigenspectra, which is directly generated from Steenbrink’s spectral theory on vanishing cohomology. We show by an example on how to compute the eigenspectra associated to a famil
Remarks on eigenspectra of isolated singularities
We introduce a simple calculus, extending a variant of the Steenbrink
spectrum, for describing Hodge-theoretic invariants of (smoothings of) isolated
singularities with (relative) automorphisms. After computing these
"eigenspectra" in the quasi-homogeneous case, we give three applications to
singularity bounding and monodromy of VHS.Comment: 23 page
Atypical location of primary cardiac lymphoma in the left heart with atypical clinical presentation: A case report and literature review
BackgroundPrimary cardiac lymphoma (PCL) is a rare and aggressive cardiac tumor with very poor prognosis that occurs mostly in the right cardiac cavity. Early diagnosis and treatment may improve its prognosis. In the present report, we describe the diagnosis and treatment of a primary cardiac diffuse large B-cell lymphoma (PC-DLBCL) with atypical location and clinical presentation. Additionally, a literature review was conducted to summarize the current knowledge of the disease.Case PresentationA 71-year-old man visited his local hospital because of syncope, recurrent chest tightness, shortness of breath, palpitations, and profuse sweating for more than 20 days. Chest radiography revealed a mediastinal mass. Cardiac computed tomography (CT) showed multiple enlarged mediastinal lymph nodes. Transthoracic echocardiography (TTE) showed a cardiac mass in the posterior–inferior wall of the left atrium. He was then transferred to our hospital for positron emission tomography-CT (PET-CT) which showed active uptake of fluorodeoxyglucose both in the cardiac mass and in the multiple enlarged mediastinal lymph nodes. Biopsy of the enlarged mediastinal lymph nodes was carried out by using video-assisted thoracic surgery (VATS) technique, and pathological examination confirmed the subtype of PC-DLBCL, Stage IV, NCCN IPI 3. Therefore, the patient received a combination of chemotherapy and immunotherapy with R-CDOP (rituximab, cyclophosphamide, liposome doxorubicin, vincristine, and prednisone). After four courses of treatment in 4 months, the cardiac lymphoma and the enlarged mediastinal lymph nodes achieved complete remission with mild side effects of the chemotherapy.ConclusionEarly diagnosis and a precise choice of chemotherapy and immunotherapy based on cardiac imaging and pathological examination may improve the prognosis of PC-DLBCL in an atypical location
High Mannose-Binding Lectin Serum Levels Are Associated with Diabetic Retinopathy in Chinese Patients with Type 2 Diabetes.
To investigate mannose-binding lectin (MBL) serum levels in type 2 diabetic patients with and without diabetic retinopathy (DR).Serum MBL levels were determined in type 2 diabetic patients (N=324) as well as in 300 healthy control Subjects. Multivariate analyses were performed using logistic regression models. Receiver operating characteristic curves (ROC) was used to test the overall predict accuracy of MBL and other markers.Diabetic patients with DR and vision-threatening diabetic retinopathy (VTDR) had significantly higher MBL levels on admission (P<0.0001 and P<0.0001). MBL improved the area under the receiver operating characteristic curve of the diabetes duration for DRfrom 0.82(95% confidence interval [CI], 0.77-0.86) to 0.88(95% CI, 0.82-0.96; P<0.01) and for VDTR from 0.85(95% CI, 0.77-0.92) to 0.90(95% CI, 0.83-0.96; P<0.01). Multivariate logistic regression analysis adjusted for common risk factors showed that serum MBL levels(per log-unit increase) was an independent predictor of DR (OR=3.45; 95%CI: 1.42-7.05) and VTDR (OR=4.42; 95%CI: 1.51-8.18).MBL is a novel, independent diagnostic marker of DR in type 2 diabetic patients, suggesting that MBL may be involved in the pathogenesis of DR in diabetic patients
Nr2e1 Deficiency Augments Palmitate-Induced Oxidative Stress in Beta Cells
Nuclear receptor subfamily 2 group E member 1 (Nr2e1) has been regarded as an essential regulator of the growth of neural stem cells. However, its function elsewhere is unknown. In the present study, we generated Nr2e1 knockdown MIN6 cells and studied whether Nr2e1 knockdown affected basal beta cell functions such as proliferation, cell death, and insulin secretion. We showed that knockdown of Nr2e1 in MIN6 cells resulted in increased sensitivity to lipotoxicity, decreased proliferation, a partial G0/G1 cell-cycle arrest, and higher rates of apoptosis. Moreover, Nr2e1 deficiency exaggerates palmitate-induced impairment in insulin secretion. At the molecular level, Nr2e1 deficiency augments palmitate-induced oxidative stress. Nr2e1 deficiency also resulted in decreases in antioxidant enzymes and expression level of Nrf2. Together, this study indicated a potential protective effect of Nr2e1 on beta cells, which may serve as a target for the development of novel therapies for diabetes
Nr2e1 Deficiency Augments Palmitate-Induced Oxidative Stress in Beta Cells
Nuclear receptor subfamily 2 group E member 1 (Nr2e1) has been regarded as an essential regulator of the growth of neural stem cells. However, its function elsewhere is unknown. In the present study, we generated Nr2e1 knockdown MIN6 cells and studied whether Nr2e1 knockdown affected basal beta cell functions such as proliferation, cell death, and insulin secretion. We showed that knockdown of Nr2e1 in MIN6 cells resulted in increased sensitivity to lipotoxicity, decreased proliferation, a partial G0/G1 cell-cycle arrest, and higher rates of apoptosis. Moreover, Nr2e1 deficiency exaggerates palmitate-induced impairment in insulin secretion. At the molecular level, Nr2e1 deficiency augments palmitate-induced oxidative stress. Nr2e1 deficiency also resulted in decreases in antioxidant enzymes and expression level of Nrf2. Together, this study indicated a potential protective effect of Nr2e1 on beta cells, which may serve as a target for the development of novel therapies for diabetes