First-principles analysis of a molecular piezoelectric meta-nitroaniline

The piezoelectric and elastic properties of a molecular piezoelectric meta-nitroaniline (mNA) in its single-crystal form were investigated in the framework of first-principles density functional perturbation theory (DFPT). Results support the recent experimental findings those despite being soft and flexible, mNA''s piezoelectric coefficients are an order of magnitude greater than that of ZnO and LiNbO₃. A molecular-level insight into the piezoelectric properties of mNA is provided. These results are helpful not only for better understanding mNA, but also for developing new piezoelectric materials.

The piezoelectric and elastic properties of a molecular piezoelectric meta-nitroaniline (mNA) in its single-crystal form were investigated in the framework of first-principles density functional perturbation theory (DFPT).     

Residual HBV DNA and pgRNA viraemia is associated with hepatocellular carcinoma in chronic hepatitis B patients on antiviral therapy

Journal of Gastroenterology - We aimed to assess whether residual hepatitis B virus (HBV) viraemia is associated with HCC development. This is a case–control study of 104 patients [52 HCC and...     

The effects of Chinese herb Angelica in focal cerebral ischemia injury in the rat

This experiment was designed to study the therapeutic mechanisms of Angelica on the focal cerebral ischemia injury of the rat. The ischemic area was determined by TTC stain. And terminal deoxynucleotidyl transferase (TDT) mediated DUTP-biotin nick end labeling (TUNEL) method was applied to detect neuronal apoptosis. The expressions of Bcl-2 and Bax proteins were observed by immunohistochemical staining methods. Results show that the treatment with angelica reduced the volume of cerebral infarction (p < 0.05), and that the number of neuronal apoptosis cells decreased significantly (p < 0.01). Also the expression level of Bax protein decreased (p < 0.01). These results suggest that Angelica can reduce the number of apoptosis cells by decreasing the expression of Bax protein. This is maybe one of the mechanisms of the therapeutic effect of Angelica on focal cerebral ischemia injury.     

Multiplanar CT evaluation of aneurysm rupture signs in subarachnoid hemorrhage

Emergency Radiology - In subarachnoid hemorrhage, noncontrast CT features are used to guide the localization of ruptured aneurysms on CT angiography and DSA. Multiplanar CT may improve the...     

脊髓性肌萎缩症生物标志物的研究进展

脊髓性肌萎缩(SMA)是一种高发生率并严重影响儿童生命健康的遗传性神经肌肉病。SMA的表型异质性高、对治疗药物的反应性也不同, 因此迫切需要寻找理想的生物标志物对患者的疾病严重程度、进展及预后和药物治疗的反应等方面进行有效的评估, 为患者制定完善的个性化治疗方案和多学科管理策略。近年来SMA生物标志物的研究取得重要进展, 本文就生物标志物在SMA疾病进展、预后、治疗效果等方面的研究进行综述。     

Age-associated accumulation of CMV-specific CD8+ T cells expressing the inhibitory killer cell lectin-like receptor G1 (KLRG1)

Large clonal expansions of peripheral CD8+ T cells carrying receptors for single epitopes of CMV and EBV are common in the elderly and may be associated with an immune risk phenotype predicting mortality. Here we show that the frequency of CD8+ T cells expressing the inhibitory killer cell lectin-like receptor G1 (KLRG1), a marker of cells unable to undergo further clonal expansion, was markedly elevated in CD8+ T cells from old donors. Moreover, tetramer staining revealed that the elevated frequency of CMV-specific CD8+ T cells in the elderly was due to an accumulation of cells bearing this dominant negative receptor. The fraction of CMV-specific T cells able to secrete interferon-gamma after specific antigenic stimulation was significantly lower in the elderly than in the young, although the total number of functional cells was comparable. Therefore, the majority of the clonally expanded virus-specific CD8+ cells in the elderly was dysfunctional. Thus, T cell responses are altered in the aged by an accumulation of replicatively senescent dysfunctional T cells carrying receptors for persistent herpes viruses. The presence of clonal expansions of such virus-specific cells may shrink the available repertoire for other antigens and contribute to the increased incidence of infectious disease in the elderly.     

Epac signaling is required for hippocampus-dependent memory retrieval

Previously we uncovered a critical role for norepinephrine and β₁-adrenergic signaling in hippocampus-dependent memory retrieval. Because the β₁ receptor couples to G_s, we examine here whether cAMP is also required for contextual memory retrieval. Using pharmacologic and genetic approaches to manipulate cAMP and downstream signaling, we demonstrate that cAMP and two of its targets, protein kinase A (PKA) and exchange protein activated by cAMP (Epac), are both required for retrieval. These findings demonstrate that cAMP signaling through Epac (as well as PKA) plays an essential role in cognition.     

Thrombolysis in postinfarction angina

Postinfarction angina carries a poor prognosis, with a 20-70% incidence of recurrent myocardial infarction (MI) or death within the subsequent 3-6 months. The pathophysiologic mechanisms causing postinfarction angina may include thrombus, complex coronary arterial lesions that form a nidus for thrombus formation, inadequate collateral supply following acute MI, or intimal endothelial dysfunction. The role of thrombus has been established in the pathophysiology of Q-wave MI, and thrombolytic treatment of patients presenting with acute transmural MI has been shown to salvage left ventricular function and to reduce mortality. However, thrombolytic therapy for the acute MI does not reduce the incidence of recurrent ischemia or infarction, as is evident from the 18-26% incidence of recurrent ischemia reported in the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) and Thrombolysis in Myocardial Infarction (TIMI) trials. In the Gruppo Italiano per lo Studio della Streptochinasi nell'Infarto Miocardico (GISSI) study the incidence of reinfarction was documented as 4% in the streptokinase group, which was actually significantly greater than in the placebo group (2%). In a randomized placebo-controlled study of thrombolysis for postinfarction angina, 29 patients were randomized to placebo (P group, n = 17) or to thrombolytic therapy (T group, n = 12). Patient groups were similar with respect to age, location of MI, ejection fraction, severity of coronary artery disease, and antianginal therapy. Patients underwent coronary angiography 6 +/- 1 days postinfarction. Filling defects consistent with intracoronary thrombus was seen in 11 of 12 T group patients and in 11 of 17 P group patients prior to treatment. Lysis occurred in 7 of 11 T patients and 1 of 11 P (p less than 0.02). Holter-detected silent ischemia was compared pre- and posttherapy.(ABSTRACT TRUNCATED AT 250 WORDS)