RatUNet: residual U-Net based on attention mechanism for image denoising.

Deep convolutional neural networks (CNNs) have been very successful in image denoising. However, with the growth of the depth of plain networks, CNNs may result in performance degradation. The lack of network depth leads to the limited ability of the network to extract image features and difficults to fuse the shallow image features into the deep image information. In this work, we propose an improved deep convolutional U-Net framework (RatUNet) for image denoising. RatUNet improves Unet as follows: (1) RatUNet uses the residual blocks of ResNet to deepen the network depth, so as to avoid the network performance saturation. (2) RatUNet improves the down-sampling method, which is conducive to extracting image features. (3) RatUNet improves the up-sampling method, which is used to restore image details. (4) RatUNet improves the skip-connection method of the U-Net network, which is used to fuse the shallow feature information into the deep image details, and it is more conducive to restore the clean image. (5) In order to better process the edge information of the image, RatUNet uses depthwise and polarized self-attention mechanism to guide a CNN for image denoising. Extensive experiments show that our RatUNet is more efficient and has better performance than existing state-of-the-art denoising methods, especially in SSIM metrics, the denoising effect of the RatUNet achieves very high performance. Visualization results show that the denoised image by RatUNet is smoother and sharper than other methods.

The unique sandwich K6Be2B6H6 cluster with a real borozene B6H6 core.

Theoretical evidence is reported for a boron-based K6Be2B6H6 sandwich cluster, showing a perfectly D 6h B6H6 ring, being capped by two tetrahedral K3Be ligands. Due to the comfortable charge transfer, the sandwich is viable in [K3Be]3+[B6H6]6-[BeK3]3+ ionic complex in nature. The [B6H6]6- core with 6π aromaticity vividly imitates the benzene (C6H6), occurring as a real borozene. In contrast, the tetrahedral [K3Be]3+ ligand is 2σ three-dimensional aromatic, acting as the simple superatom. Thus, this complex possesses a collectively three-fold 2σ/6π/2σ aromaticity. The interlaminar interaction is governed by the robust electrostatic attraction. The unique chemical bonding gives rise to interesting dynamic fluxionality.

Upregulated OCT3 has the potential to improve the survival of colorectal cancer patients treated with (m)FOLFOX6 adjuvant chemotherapy.

PURPOSE: To investigate the influence of organic cation transporter 3 (OCT3) expression on the effect of the combination regimen of 5-fluorouracil, folinic acid and oxaliplatin ((m)FOLFOX6) in colorectal cancer (CRC) patients. METHODS: This is a retrospective study conducted at a single centre (Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, China). Patients with stage IIb-IV resectable CRC who were being postoperatively treated with (m)FOLFOX6 as a first-line adjuvant chemotherapy regimen for at least 5 cycles and had resected primary tumour samples available were eligible for the study. Patients who preoperatively received chemotherapy and/or radiotherapy or were treated with targeted drugs or other anticancer drugs were excluded from the study. Immunohistochemical staining and digital image analysis were used to assess OCT3 expression in tumour samples. According to OCT3 expression level, the receiver operating characteristic curve (ROC curve) was used to divide the patients into two groups. Cox proportional risk regression was performed with the forward LR (forward stepwise regression based on maximum likelihood estimation) method using SPSS17.0 software. The primary endpoint was the 2-year progression-free survival. RESULTS: In total, 57 patients were included between 2014 and 2016 according to the inclusion and exclusion criteria (22 had low OCT3 expression, and 35 had high OCT3 expression). The mean age was 55.7 (30-74) years, and 37 of the total patients were male. According to TNM stage, 5 patients had stage IV disease, 44 patients had stage III disease, and 8 patients had stage II disease. Through Cox regression analysis, we found that among patients receiving the (m)FOLFOX6 regimen, those with higher OCT3 expression had a higher two-year progression-free survival rate than those with lower OCT3 expression (P = 0.038). The hazard ratio of patients with high OCT3 expression compared with patients with low OCT3 expression was 0.247. Besides, it was found that the age of patients was negatively correlated with expression level of OCT3, which can explain why patients over 70 years do not benefit from oxaliplatin-containing chemotherapy. CONCLUSIONS: High OCT3 expression in CRC tissues may be a protective factor for CRC patients treated with (m)FOLFOX6.

In-vitro and in situ assessment of the efflux of five antidepressants by breast cancer resistance protein.

OBJECTIVES: Antidepressants need to penetrate the blood-brain barrier (BBB) to exert their functions in the central nervous system. Breast cancer resistance protein (BCRP), an efflux transporter abundantly expressed in the BBB, prevents the accumulation of many drugs in the brain. This study aimed to identify whether five commonly used antidepressants (sertraline, duloxetine, fluoxetine, amitriptyline and mirtazapine) are BCRP substrates. METHODS: A combination of bidirectional transport and intracellular accumulation experiments was conducted on BCRP-overexpressing MDCKII and wild-type (WT) cells, and in situ brain perfusion was conducted in rats. KEY FINDINGS: The bidirectional transport study revealed that the net efflux ratio (NER) of sertraline reached 2.08 but decreased to 1.06 when co-incubated with Ko143, a selective BCRP inhibitor. Conversely, the other four antidepressants did not appear to be BCRP substrates, due to their low NER values (<1.5). The accumulation of sertraline in MDCKII-BCRP cells was significantly lower than that in MDCKII-WT cells. The presence of Ko143 significantly increased the sertraline accumulation in MDCKII-BCRP cells but not in MDCKII-WT cells. Brain perfusion showed that the permeability of 1 and 5 µm sertraline was significantly higher in the presence of Ko143. CONCLUSIONS: Taken together, BCRP is involved in sertraline efflux.

Altered microRNAs expression profiling in mice with diabetic neuropathic pain.

Neuropathic pain is one of the most common chronic complications of diabetes mellitus, one hallmark of which is tactile allodynia. However, the molecular mechanisms underlying tactile allodynia are not well understood. It has been demonstrated that microRNAs (miRNAs) are essential regulators of gene expression in the nervous system where they contribute to neuronal plasticity. Thus, in this study, we investigated the differentially expressed microRNAs in the lumbar spinal dorsal horn of streptozotocin (STZ)-induced diabetic neuropathic pain (DNP) mice and vehicle controls. Results from miRNA microarrays showed that 42 miRNAs were significantly altered in DNP spinal cord tissue (P<0.05, fold change: ⩾ 2) compared with control sample. Among them, 21 miRNAs were significantly up-regulated while the other 21 down-regulated. Further validation by quantitative real-time polymerase chain reaction (qRT-PCR) indicated that the 2 significant differentially expressed candidate miRNAs (miR-184-5p and miR-190a-5p) in DNP tissue showed the same changes as in the microarray analysis. The bioinformatics analysis revealed that some of the differentially expressed miRNAs after DNP were potential regulators of some inflammation associated with genes that are known to be involved in the pathogenesis of DNP. These findings suggest that aberrant expression of miRNAs may contribute to the pathogenesis of DNP and are potential targets for therapeutic interventions following DNP.