Neuronal representation of working memory in the medial prefrontal cortex of rats

Working memory is a process for short-term active maintenance of information. Behavioral neurophysiological studies in monkeys have demonstrated that the dorsolateral prefrontal cortex (dlPFC) is a key cortical region for working memory. The medial prefrontal cortex (mPFC) in rats is a cortical area similar to the dlPFC in monkeys in terms of anatomical connections, and is also required for behavioral performance on working-memory tasks. However, it is still controversial regarding whether and how mPFC neurons encode working memory. In the present study, we trained rats on a two-choice spatial delayed alternation task in Y maze, a typical working memory task for rodents, and investigated neuronal activities in the mPFC when rats performed the task. Our results show that, (1) inactivation of the mPFC severely impaired the performance of rats on the task, consistent with previous studies showing the importance of the mPFC for working-memory tasks; (2) 93.7% mPFC cells (449 in 479) exhibited changes in spiking frequency that were temporally locked with the task events, some of which, including delay-related cells, were tuned by spatial information; (3) differential delay activities in individual mPFC cells appeared transiently and sequentially along the delay, especially during the early phase of the delay; (4) some mPFC cells showed no change in discharge frequency but exhibited differential synchronization in firing during the delay. The present results suggest that mPFC neurons in rats are involved in encoding working memory, via increasing firing frequency or synchronization

Diagnostic value of two dimensional shear wave elastography combined with texture analysis in early liver fibrosis.

BACKGROUND: Staging diagnosis of liver fibrosis is a prerequisite for timely diagnosis and therapy in patients with chronic hepatitis B. In recent years, ultrasound elastography has become an important method for clinical noninvasive assessment of liver fibrosis stage, but its diagnostic value for early liver fibrosis still needs to be further improved. In this study, the texture analysis was carried out on the basis of two dimensional shear wave elastography (2D-SWE), and the feasibility of 2D-SWE plus texture analysis in the diagnosis of early liver fibrosis was discussed. AIM: To assess the diagnostic value of 2D-SWE combined with textural analysis in liver fibrosis staging. METHODS: This study recruited 46 patients with chronic hepatitis B. Patients underwent 2D-SWE and texture analysis; Young\u27s modulus values and textural patterns were obtained, respectively. Textural pattern was analyzed with regard to contrast, correlation, angular second moment (ASM), and homogeneity. Pathological results of biopsy specimens were the gold standard; comparison and assessment of the diagnosis efficiency were conducted for 2D-SWE, texture analysis and their combination. RESULTS: 2D-SWE displayed diagnosis efficiency in early fibrosis, significant fibrosis, severe fibrosis, and early cirrhosis (AUC \u3e 0.7, P \u3c 0.05) with respective AUC values of 0.823 (0.678-0.921), 0.808 (0.662-0.911), 0.920 (0.798-0.980), and 0.855 (0.716-0.943). Contrast and homogeneity displayed independent diagnosis efficiency in liver fibrosis stage (AUC \u3e 0.7, P \u3c 0.05), whereas correlation and ASM showed limited values. AUC of contrast and homogeneity were respectively 0.906 (0.779-0.973), 0.835 (0.693-0.930), 0.807 (0.660-0.910) and 0.925 (0.805-0.983), 0.789 (0.639-0.897), 0.736 (0.582-0.858), 0.705 (0.549-0.883) and 0.798 (0.650-0.904) in four liver fibrosis stages, which exhibited equivalence to 2D-SWE in diagnostic efficiency (P \u3e 0.05). Combined diagnosis (PRE) displayed diagnostic efficiency (AUC \u3e 0.7, P \u3c 0.01) for all fibrosis stages with respective AUC of 0.952 (0.841-0.994), 0.896 (0.766-0.967), 0.978 (0.881-0.999), 0.947 (0.835-0.992). The combined diagnosis showed higher diagnosis efficiency over 2D-SWE in early liver fibrosis (P \u3c 0.05), whereas no significant differences were observed in other comparisons (P \u3e 0.05). CONCLUSION: Texture analysis was capable of diagnosing liver fibrosis stage, combined diagnosis had obvious advantages in early liver fibrosis, liver fibrosis stage might be related to the hepatic tissue hardness distribution

Antioxidant and antibacterial activity of Toddalia asiatica (Linn) Lam root extracts

Background: Toddalia asiatica (Linn) Lam is a woody vine that is used medicinally in China, India, and East Africa. The aim of the present study was to examine the antioxidant and antibacterial activity of the roots of Toddalia asiatica (Linn) Lam (TA).Materials and Methods: The antioxidant capacity of TA roots was determined using 1,1 iphenyl-2-picrylhydrazyl (DPPH), 2,2´-azino-bis (3-ethylbenzo-thiazoline-6-sulfonicacid) (ABTS), and the ferric reducing antioxidant potential (FRAP) assay. The antimicrobial activity of TA against Staphylococcus aureus (SA), methicillin-resistant S. aureus (MRSA), and extended spectrum β-lactamase positive S. aureus (ESBLs-SA) was screened.Results: Methanol and ethyl acetate extracts of TA exhibited strong antioxidant activity. The methanol extract had the highest antioxidant activity (DPPH, IC50=41.45 μg/mL; ABTS, IC50=8.34 μg/mL; FRAP=1304.8 ± 60.38 μmol Trolox equivalent (TE)/g), which was close to that of the positive control, butylated hydroxytoluene (BHT). The petroleum ether extract of TA showed the highest antimicrobial activity (SA, minimum inhibitory concentration (MIC) = 250 μg/disc; MRSA, MIC=125 μg/disc) when compared with that of ethyl acetate extract (SA, MIC=250 μg/disc) and methanol extract.Conclusions: Investigation of methanol, petroleum ether, and ethyl acetate extracts of TA root revealed robust antioxidant activity in methanol extracts and strong antimicrobial activity against SA and MRSA in petroleum ether extracts.Keywords: Toddalia asiatica (Linn) Lam; antioxidant; antibacteria

The semi-leptonic form factors of Λb→Λc\Lambda_{b}\to\Lambda_{c} and Ξb→Ξc\Xi_{b}\to\Xi_{c} in QCD sum rules

In this work, the full leading order results of the form factors for $\Xi_{b}\to\Xi_{c}$ and $\Lambda_{b}\to\Lambda_{c}$ are obtained in QCD sum rules. Contributions from up to dim-5 have been considered. For completeness, we also study the two-point correlation function to obtain the pole residues of $\Xi_{Q}$ and $\Lambda_{Q}$, and higher accuracy is achieved. For the three-point correlation function, since stable Borel regions can not be found, about $20\%$ uncertainties are introduced for the form factors of $\Xi_{b}\to\Xi_{c}$ and $\Lambda_{b}\to\Lambda_{c}$. Our results for the form factors are consistent with those of the Lattice QCD within errors.Comment: 17 pages, 5 figure