[A diffusion-weighted image denoising algorithm using HOSVD combined with Rician noise corrected model]

OBJECTIVE

To propose a novel diffusion-weighted (DW) image denoising algorithm based on HOSVD to improve the signal-to-noise ratio (SNR) of DW images and the accuracy of subsequent quantization parameters.

METHODS

This HOSVDbased denoising method incorporated the sparse constraint and noise-correction model. The signal expectations with Rician noise were integrated into the traditional HOSVD denoising framework for direct denoising of the DW images with Rician noise. HOSVD denoising was performed directly on each local DW image block to avoid the stripe artifacts. We compared the proposed method with 4 image denoising algorithms (LR + Edge, GL-HOSVD, BM3D and NLM) to verify the effect of the proposed method.

RESULTS

The experimental results showed that the proposed method effectively reduced the noise of DW images while preserving the image details and edge structure information. The proposed algorithm was significantly better than LR +Edge, BM3D and NLM in terms of quantitative metrics of PSNR, SSIM and FA-RMSE and in visual evaluation of denoising images and FA images. GL-HOSVD obtained good denoising results but introduced stripe artifacts at a high noise level during the denoising process. In contrast, the proposed method achieved good denoising results without causing stripe artifacts.

CONCLUSION

This HOSVD-based denoising method allows direct processing of DW images with Rician noise without introducing artifacts and can provide accurate quantitative parameters for diagnostic purposes.

[Analysis of diagnosis, treatment and risk classification of blunt thoracic aortic injury]

Objective: Propose a new risk classification system for blunt thoracic aortic injury and explore its treatment strategies. Methods: After the retrospective analysis of clinical data from 68 patients with blunt thoracic aortic injury in the First Affiliated Hospital of Zhengzhou University from November 2016 to October 2020, there were 56 males and 12 females, among these patients, the median age was 45(21-69). According to the degree of aortic injury and the combined injury, the patients were scored for aortic injury, and the risk of the patients were graded into following three types: low-risk group (score ≤ 2 points) 12 cases, intermediate-risk group (3 points ≤ score ≤ 5 points) 41 cases, high-risk group (score ≥ 6 points) 15 cases. Analyzing the effects of treatments received by patients in different grades on the prognosis. Patients were followed up through hospitalization or outpatient clinics at 1, 3, 6, 12 months after surgery and every year thereafter. Results: Of the 68 patients, 21 received non-surgical treatment and 47 received surgical repair, including 6 open surgery and 41 thoracic aortic endovascular repair. There were 16 cases of emergency operation and 31 cases of delayed operation. Twelve low-risk patients were treated with non-surgical treatment, and only 1 patient died of lung infection, with a mortality rate of 8.3% (1/12). There were 8 deaths in 41 moderate-risk patients, with a mortality rate of 19.5% (8/41), and the aortic-related mortality rate was 9.8% (4/41), and the operative mortality rate was 10.8% (4/37). The total mortality of 15 high-risk patients was 40% (6/15), and the aortic-related mortality rate was 30.0% (5/15), and the mortality rate of surgical patients was 10% (1/10). During the follow-up period of 5 to 52 months, no deaths occurred outside the hospital. According to the risk grading, there were significant differences in the aortic-related mortality of each grade (χ²=7.840, P=0.020). During the follow-up of 5-52 months, 1 case had type Ⅰ endoleak, 1 case of cerebral infarction, and 1 case of acute renal failure. Conclusion: According to the patient's degree of aortic injury and combined injury, the risk classification helps to choose the appropriate treatment.

Silence of ATAD2 inhibits proliferation of colorectal carcinoma via the Rb-E2F1 signaling

OBJECTIVE

This study aims to clarify the potential function of ATAD2 (ATPase family, AAA domain containing 2) in regulating proliferative and apoptotic abilities of colorectal carcinoma (CRC).

PATIENTS AND METHODS

ATAD2 levels in CRC specimens and cell lines were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Overall survival in CRC patients with high or low level of ATAD2 was assessed by Kaplan-Meier method. The correlation between ATAD2 level and clinical characteristics of CRC patients was analyzed by χ2 test. Univariable and multivariable Cox regression models were generated to illustrate potential risk factors for the overall survival of CRC. After knockdown of ATAD2 in SW620 cells, relative levels of Cyclin D1, ppRb, pRb, E2F1, Cyclin E and cleaved Caspase 3 were detected by Western blot. Regulatory effects of ATAD2 on viability, clonality, cell cycle distribution, and apoptosis in SW620 and HCT15 cells were examined by a series of functional experiments.

RESULTS

Upregulated ATAD2 in CRC was correlated to tumor size, tumor node metastasis (TNM) staging, and histological classification of CRC. High level of ATAD2 predicted poor prognosis in CRC patients. Cox regression test suggested that ATAD2 level, tumor size, TNM staging and histological classification were independent factors influencing overall survival in CRC. Knockdown of ATAD2 reduced viability and clonality in SW620 and HCT15 cells. In addition, cell cycle was arrested in G1 phase and apoptosis was stimulated in CRC cells with ATAD2 knockdown. In SW620 cells transfected with ATAD2 shRNA, protein levels of Cyclin D1, ppRb, E2F1 and Cyclin E were downregulated, and cleaved Caspase 3 was upregulated.

CONCLUSIONS

ATAD2 is upregulated in CRC tissues and correlated to poor prognosis of CRC patients. It exerts an anti-proliferation role in CRC by arresting cell cycle in G1/S phase and triggering apoptosis via the Rb-E2F1 signaling.

Long noncoding RNA TTN-AS1 promotes the proliferation and migration of prostate cancer by inhibiting miR-1271 level

OBJECTIVE

Prostate cancer is one of the most common malignant tumors. Recently, the role of long noncoding RNAs (lncRNAs) in tumor progression has been well concerned by numerous researchers. In this research, lncRNA TTN-AS1 was studied to identify its biological function in the progression of prostate cancer.

PATIENTS AND METHODS

Firstly, Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) was conducted to measure TTN-AS1 expression in prostate cancer tissues. Furthermore, in vitro role of TTN-AS1 in regulating prostate cancer cells was assessed. Tumor formation assay was conducted in NOD/SCID mice to explore the in vitro function of TTN-AS1. In addition, the luciferase reporter gene assay was performed to analyze the relationship between TTN-AS1 and miR-1271.

RESULTS

TTN-AS1 expression was remarkably higher in prostate cancer samples compared with that of corresponding ones. Moreover, proliferation and migration of prostate cancer cells were inhibited after TTN-AS1 was silenced. MiR-1271 was upregulated after the silence of TTN-AS1. Further mechanism assays showed that miR-1271 was a direct target of TTN-AS1 in prostate cancer. In addition, tumor formation and metastasis abilities were inhibited after in vivo knockdown of TTN-AS1.

CONCLUSIONS

Our study discovers a potential oncogene in prostate cancer and demonstrates that TTN-AS1 enhances cell proliferation and migration via sponging miR-1271.

Jasmonic acid-mediated enhanced regulation of oxidative, glyoxalase defense system and reduced chromium uptake contributes to alleviation of chromium (VI) toxicity in choysum (Brassica parachinensis L.)

The cultivation of leafy vegetables on metal contaminated soil embodies a serious threat to yield and quality. In the present study, the potential role of exogenous jasmonic acid (JA; 0, 5, 10, and 20 µM) on mitigating chromium toxicity (Cr; 0, 150, and 300 µM) was investigated in choysum (Brassica parachinensis L.). With exposure to increasing Cr stress levels, a dose-dependent decline in growth, photosynthesis, and physio-biochemical attributes of choysum plants was observed. An increase in Cr levels also resulted in oxidative stress closely associated with higher lipoxygenase activity (LOX), hydrogen peroxide (H₂O₂) generation, lipid peroxidation (MDA), and methylglyoxal (MG) levels. Exogenous application of JA alleviated the Cr-induced phytotoxic effects on photosynthetic pigments, gas exchange parameters, and restored growth of choysum plants. While exposed to Cr stress, JA supplementation induced plant defense system via enhanced regulation of antioxidant enzymes, ascorbate and glutathione pool, and the glyoxalase system enzymes. The coordinated regulation of antioxidant and glyoxalase systems expressively suppressed the oxidative and carbonyl stress at both Cr stress levels. More importantly, JA restored the mineral nutrient contents, restricted Cr uptake, and accumulation in roots and shoots of choysum plants when compared to the only Cr-stressed plants. Overall, the application of JA2 treatment (10 µM JA) was more effective and counteracted the detrimental effects of 150 µM Cr stress by restoring the growth and physio-biochemical attributes to the level of control plants, while partially mitigated the detrimental effects of 300 µM Cr stress. Hence, JA application might be considered as an effective approach for minimizing Cr uptake and its detrimental effects in choysum plants grown on contaminated soils.

Comparative effectiveness of Se translocation between low-Se and high-Se rice cultivars under Se fertilization

The production of natural selenium (Se)-rich food by using a high-Se crop cultivar is beneficial to human health and environmental safety; however, the underlying mechanism of different Se-accumulation ability between high- and low-Se rice cultivars remains unclear. A low-grain-Se cultivar and high-grain-Se cultivar of rice were used as test materials, and two levels of Se (0 and 0.5 mg kg^-1) were arranged in a randomized design containing twelve replicates. The dynamic changes of shoot Se concentration and accumulation, xylem sap Se concentration, shoot and grain Se distribution, Se transporters genes (OsPT2, Sultr1;2, NRT1.1B) expression of the high- and low-Se rice cultivars were determined. The shoot Se concentration and accumulation of the high-Se rice showed a greater degree of reduction than those of the low-Se rice during grain filling stage, indicating that leaves of high-Se rice served as a Se source and supplied more Se for the growth centre grain. The expression levels of OsPT2, NRT1.1B and Sultr1;2 in the high-Se rice cultivar were significantly higher than those in the low-Se rice cultivar, which indicated that the high-Se rice cultivar possessed better transport carriers. The distribution of Se in grain of the high-Se rice cultivar was more uniform, whereas the low-Se cultivar tended to accumulate Se in embryo end. The stronger reutilization of Se from shoots to grains promoted by increased transporters genes expression and optimized grain storage space may explain how the high-Se rice cultivar is able to accumulate more Se in grain.

Functional divergence of white genes in Henosepilachna vigintioctopunctata revealed by RNA interference

Henosepilachna vigintioctopunctata is a serious pest of Solanaceae and Cucurbitaceae in many Asian countries. RNA interference (RNAi) can effectively reduce transcript abundance in this beetle, offering opportunities to explore the biological function of specific genes. The white gene encodes a half-type ATP-binding cassette transporter that plays an essential role in tryptophan, guanine and uric acid transport across membranes. Mutations that disrupt the function of white are known to cause eye pigmentation phenotypes in many insect species. Here, we found evidence for five white gene paralogues present in H. vigintioctopunctata transcriptome datasets sequenced from a range of developmental stages. We individually knocked down each of the five white genes through the injection of corresponding double-stranded RNAs (dsRNAs) to the fourth-instar larvae to determine whether functional divergence has occurred. We found that injecting 1 μg dswhite3 caused compound eye colour of pupae and adults to develop as red/brown and brown, respectively, compared with black eyes in control beetles. Injection of 2 μg dswhite3 increased RNAi efficacy and produced a clearer eye colour phenotype. At both doses, the ocular diaphragm (a ring of black pigment surrounding each eye) did not change in the white3 RNAi hypomorphs. Moreover, our data revealed that injection of dswhite2 at the fourth-instar larval stage impaired the climbing ability of both male and female adults. Our results confirmed, for the first time, functional divergence of duplicated white genes in an insect species.

A new micro/nano-touch-trigger probe using an optoelectronic sensor with a wedge prism

In this paper, we propose a new touch-trigger probe with high precision and a large permissible measurement range. A wedge prism was used in the sensing unit to achieve 3D detection using only one optoelectronic sensor. The measurement range was expanded from ±8 µm to ±14 µm through the new optical structure. The probe has uniform stiffness and uniform sensitivity. Some experiments were performed to investigate the performance of the probe. It was found that the probe has a resolution of 10 nm and a repeatability of less than 9.1 nm. The applicability of the probe was also verified.

Brain areas associated with clinical and cognitive insight in psychotic disorders: A systematic review and meta-analysis

In the past years, ample interest in brain abnormalities related to clinical and cognitive insight in psychosis has contributed several neuroimaging studies to the literature. In the current study, published findings on the neural substrates of clinical and cognitive insight in psychosis are integrated by performing a systematic review and meta-analysis. Coordinate-based meta-analyses were performed with the parametric coordinate-based meta-analysis approach, non-coordinate based meta-analyses were conducted with the metafor package in R. Papers that could not be included in the meta-analyses were systematically reviewed. Thirty-seven studies were retrieved, of which 21 studies were included in meta-analyses. Poorer clinical insight was related to smaller whole brain gray and white matter volume and gray matter volume of the frontal gyri. Cognitive insight was predominantly positively associated with structure and function of the hippocampus and ventrolateral prefrontal cortex. Impaired clinical insight is not associated with abnormalities of isolated brain regions, but with spatially diffuse global and frontal abnormalities suggesting it might rely on a range of cognitive and self-evaluative processes. Cognitive insight is associated with specific areas and appears to rely more on retrieving and integrating self-related information.

A simple approach to prepare self-assembled, nacre-inspired clay/polymer nanocomposites

Inspired by the relationship between the well-ordered architecture of aragonite crystals and biopolymers found in natural nacre, we present a facile strategy to construct large-scale organic/inorganic nacre-mimetics with hierarchical structure via a water-evaporation driven self-assembly process. We connect LAPONITE®-nanoclay platelets with each other using carboxymethyl cellulose, a cellulose derivative, thus creating thin, flexible films with a local brick-and-mortar architecture. The dried films show a pronounced resistance against tensile forces allowing for stronger thin films than nacre. In terms of functionalities, we report excellent glass-like transparency along with exceptional shape-persistent flame shielding. We also demonstrate that through metal ion-coordination we can further strengthen the interactions between the polymers and the nanoclays, and thus enhanced mechanical, and thermal properties as well as resistance against swelling and dissolution in aqueous environments. We believe that our simple pathway to fabricate such versatile polymer/clay nanocomposites can open avenues for inexpensive production of environmentally friendly, biomimetic materials in aerospace, wearable electrical devices, and in the food packaging industry.

Clinical characteristics of two human-to-human transmitted coronaviruses: Corona Virus Disease 2019 vs. Middle East Respiratory Syndrome Coronavirus

OBJECTIVE

Subsequent to a global outbreak of the Middle East Respiratory Syndrome (MERS) in 2012, a novel human coronavirus, known as Corona Virus Disease 2019 (COVID-19) has caused a major disease outbreak. The aim of this study was to perform a systematic review to compare epidemiological, clinical, and laboratory features of COVID-19 and MERS-COV populations.

MATERIALS AND METHODS

We searched PubMed, EMBASE, and Cochrane Central Register of Controlled Trials database to identify potential studies that have reported COVID-19 or MERS-COV disease. Epidemiology, clinical, and laboratory outcomes, intensive care unit (ICU) admission rates, discharge rates, and fatality rates were evaluated using Graph-Pad Prism software.

RESULTS

A total of forty-two studies were included in our research, involving in 4,720 patients (COVID-19 = 2,012, MERS-COV = 2,708). The present study revealed that main clinical manifestations of both COVID-19 and MERS-COV populations are fever, cough and generalized weakness or myalgia, and Acute Respiratory Distress Syndrome (ARDS) is the main complication. The COVID-19 population has a lower rate of ICU admissions, discharges, fatalities, and shorter incubation periods than those of MERS-COV population.

CONCLUSIONS

The main clinical features of both COVID-19 and MERS-COV populations are fever, cough and generalized weakness or myalgia. ARDS is the main complication of both populations. COVID-19 cases have a shorter incubation period and lower rate of ICU admissions, discharges and fatalities compared to MRES-COV population.

Development of an x-ray detector by polycrystalline diamond and its application in Z-pinch x-ray detection

Large-grain-sized polycrystalline diamond films are fabricated by electron assisted chemical vapor deposition. A pure SP3 carbon bond in the cubic lattice structure is confirmed by Raman spectrum analysis. The grain size is on the order of several hundreds of μm or larger. Interlaced-finger electrodes are imprinted onto a 6 × 6 mm² × 500 µm film to fabricate the x-ray detector. The width of every finger is 25 µm, and the distance between nearby fingers is 25 μm. Strong x ray irradiates when a pulsed current flows through a double-layer nested tungsten wire array in the Z-pinch. This diamond detector now works as one of the main x-ray detectors for the Z-pinch device. The diamond detector is calibrated using a plastic scintillator. The comparison between the signal measured by these two methods confirms that the large-grain-sized polycrystalline diamond is a good candidate for the detection of nanosecond pulsed x ray.