Antimicrobial Peptides Targeting Streptococcus mutans: Current Research on Design, Screening and Efficacy.

Antimicrobial peptides (AMPs) are small-molecule peptides that play a vital role in the nonspecific immune defense system of organisms. They mainly kill microorganisms by physically destroying the cell membrane and causing the leakage of contents. AMPs have attracted much attention as potential alternatives to antibiotics due to their low susceptibility to resistance. Streptococcus mutans (S. mutans) is one of the main causative agents of human dental caries. The design, screening, and efficacy evaluation of AMPs targeting S. mutans offer new possibilities for the prevention and treatment of oral diseases, especially dental caries, in the future. This article reviews AMPs from different sources that have inhibitory effects on S. mutans, discusses the mechanism of action of AMPs against S. mutans biofilms, and focuses on the research progress of screening methods, design modification, and biological activity evaluation of AMPs. We hope to provide insights and reference value for the development of new biologics.

Ash problems and prevention measures in power plants burning high alkali fuel: Brief review and future perspectives.

Large-scale utilization of high-alkali fuels is considered an effective solution for alleviating energy shortages and reducing CO2 emissions. However, combustion of high-alkali fuels in boilers releases alkali metals into the flue gas, which leads to severe ash deposition and corrosion on the heating surface. Consequently, research into the efficient use of highly alkaline fuels has been conducted in recent years. In this review, ash issues and measures for their prevention during high-alkali fuel combustion are summarized. First, the characteristics of fly ash produced from high-alkali fuel combustion are reviewed, and the form, migration, and deposition characteristics of alkali metals are summarized. Subsequently, research progress of high alkali fuel ash is introduced in detail. Mechanisms of slagging, fouling, corrosion on the heating surface and the selective catalytic reduction (SCR) unit deactivation are summarized. Prevention and control methods for the high-alkali fuel ash problem are then introduced. Finally, based on current research, existing problems and future development directions for high-alkali fuel research are proposed. Through this review, we hope to provide insights into the effective utilization of high-alkali fuels.

Ga2O3-Based Solar-Blind Position-Sensitive Detector for Noncontact Measurement and Optoelectronic Demodulation.

As a kind of photodetector, position-sensitive-detectors (PSDs) have been widely used in noncontact photoelectric positioning and measurement. However, fabrications and applications of solar-blind PSDs remain yet to be harnessed. Herein, we demonstrate a solar-blind PSD developed from a graphene/Ga2O3 Schottky junction with a 25-nanometer-thick Ga2O3 film, in which the absorption of the nanometer-thick Ga2O3 is enhanced by multibeam interference. The graphene/Ga2O3 junction exhibits a responsivity of 48.5 mA/W and a rise/decay time of 0.8/99.8 µs at zero bias. Moreover, the position of the solar-blind spot can be determined by the output signals of the PSD. Using the device as a sensor of noncontact test systems, we demonstrate its application in measurement of angular, displacement, and light trajectory. In addition, the position-sensitive outputs have been used to demodulate optical signals into electrical signals. The results may prospect the application of solar-blind PSDs in measurement, tracking, communication, and so on.

Deep-Learning-Based Automatic Detection of Photovoltaic Cell Defects in Electroluminescence Images.

Photovoltaic (PV) cell defect detection has become a prominent problem in the development of the PV industry; however, the entire industry lacks effective technical means. In this paper, we propose a deep-learning-based defect detection method for photovoltaic cells, which addresses two technical challenges: (1) to propose a method for data enhancement and category weight assignment, which effectively mitigates the impact of the problem of scant data and data imbalance on model performance; (2) to propose a feature fusion method based on ResNet152-Xception. A coordinate attention (CA) mechanism is incorporated into the feature map to enhance the feature extraction capability of the existing model. The proposed model was conducted on two global publicly available PV-defective electroluminescence (EL) image datasets, and using CNN, Vgg16, MobileNetV2, InceptionV3, DenseNet121, ResNet152, Xception and InceptionResNetV2 as comparative benchmarks, it was evaluated that several metrics were significantly improved. In addition, the accuracy reached 96.17% in the binary classification task of identifying the presence or absence of defects and 92.13% in the multiclassification task of identifying different defect types. The numerical experimental results show that the proposed deep-learning-based defect detection method for PV cells can automatically perform efficient and accurate defect detection using EL images.

Ga2O3 based multilevel solar-blind photomemory array with logic, arithmetic, and image storage functions.

Photomemories offer great opportunities for multifunctional integration of optical sensing, data storage, and processing into one single device. However, little attention has been paid to photomemories working in the solar-blind region so far, which may have unique advantages of insusceptibility to ambient light and higher capacity. Herein, we propose and demonstrate a Ga2O3 based solar-blind photomemory array with logic, arithmetic, and optoelectronic memory functions. The device shows n-type field effect-transistor performance with an on/off ratio as high as 106, a responsivity of 8 × 103 A W-1, and a detectivity of 1.42 × 1014 Jones, all of which are amongst the best values ever reported for Ga2O3 based photodetectors. Based on the trapping and de-trapping process of holes in Ga2O3, multilevel data storage can be realized from the device. Simultaneously, the optical and electrical mixed basic logic of reconfigurable "AND" and "OR" operations have been realized in a single cell through the co-regulation of solar-blind light and the grid voltage. In addition, the photomemory can perform counting and addition operations, and the photomemory array can be utilized to realize solar-blind image storage. The results suggest that Ga2O3 may have potential applications in high-performance information storage, computing, and communications.

Reviews and advances in diagnostic research on Schistosoma japonicum.

Schistosomiasis is an acute and chronic parasitic disease caused by blood flukes (trematode worms) of the genus Schistosoma. Schistosoma japonicum (S. japonicum) infection has decreased significantly in prevalence and intensity of infection in China. However, this disease still remains a serious public health problem in some endemic areas of the Philippines and Indonesia. Thus, more accurate and sensitive methods are much needed for further control of this disease. Here, we review the research progress in techniques for the diagnosis of S. japonicum infection.

Evaluation of a real-time PCR assay for diagnosis of schistosomiasis japonica in the domestic goat.

BACKGROUND: Schistosomiasis japonica is an infectious disease caused by Schistosoma japonicum that seriously endangers human health. Domestic animals have important roles in disease transmission and goats are considered a primary reservoir host and source of infection. The prevalence and intensity of schistosomiasis infections have significantly decreased in China, and a more sensitive, specific detection method is urgently needed. The aim of this study was to develop a real-time PCR assay for accurate detection of S. japonicum infection in goats. METHODS: A real-time PCR method for detecting schistosomiasis japonica in goats was developed by amplification of a specific S. japonicum DNA fragment, and validated using a total of 94 negative and 159 positive plasma and serum samples collected in our previous study of S. japonicum infection. Both plasma and serum samples were evaluated by real-time PCR and enzyme-linked immunosorbent assay (ELISA). In addition, 120 goat plasma samples from an S. japonicum-endemic area (Wangjiang) and 33 from a non-endemic region (Weihai) were collected and evaluated using our method. RESULTS: The sensitivity and specificity of the real-time PCR for detecting infected samples were 98.74% (157/159, 95% CI: 95.53-99.85%) and 100% (94/94, 95% CI: 96.15-100%), respectively. For the ELISA, sensitivity and specificity were 98.11% (156/159, 95% CI: 94.59-99.61%) and 90.43% (85/94, 95% CI: 82.60-95.53%), respectively. Further, we found positivity rates for S. japonicum infection in Wangjiang and Weihai of 8.33% (10/120, 95% CI: 4.07-14.79%) and 0% (0/33, 95% CI: 0-10.58%), respectively. CONCLUSIONS: The results of this study indicate that our real-time PCR method exhibits higher sensitivity and specificity than ELISA and is a useful method for detection of S. japonicum infection in goats.

Acceleration of Hg0 Adsorption onto Natural Sphalerite by Cu2+ Activation during Flotation: Mechanism and Applications in Hg0 Recovery.

The rate of gaseous Hg0 adsorption onto natural sphalerite increased by approximately 1.9-7.7 times after Cu2+ activation during flotation of the natural sphalerite to remove impurities. Via a new pathway involving CuS, physically adsorbed Hg0 was oxidized by CuS to HgS on natural sphalerite after Cu2+ activation. In a similar intrinsic ZnS pathway, physically adsorbed Hg0 was oxidized by ZnS to HgS. The rate of the CuS pathway for Hg0 capture was generally significantly larger than that of the intrinsic ZnS pathway. Thus, Hg0 adsorption onto natural sphalerite was notably accelerated after Cu2+ activation. However, the kinetic analysis indicated that the capacity of natural sphalerite for Hg0 capture did not vary. Because the properties of the activated sphalerite for Zn smelting were barely degraded after Hg0 capture, the spent activated sphalerite for Hg0 capture can be reused for Zn smelting. Moreover, most of the gaseous Hg0 captured by activated sphalerite can be recovered eventually as liquid Hg0 in the condenser unit of Zn smelters. Thus, Hg0 recovery by activated sphalerite is a cost-effective and environmentally friendly technology to recover Hg0 from Zn smelting flue gas, thus replacing the complex and dangerous Boliden-Norzink process.

Significant Enhancement of Gaseous Elemental Mercury Recovery from Coal-Fired Flue Gas by Phosphomolybdic Acid Grafting on Sulfurated γ-Fe2O3: Performance and Mechanism.

The existing technologies to control Hg emissions from coal-fired power plants can be improved to achieve the centralized control of Hg0 emissions, which continue to pose a risk of Hg exposure to human populations. In this work, MoSx@γ-Fe2O3, formed by the sulfuration of phosphomolybdic acid (HPMo)-grafted γ-Fe2O3, was developed as a magnetic and regenerable sorbent to recover gaseous Hg0 from coal-fired flue gas as a cobenefit to the use of wet electrostatic precipitators. The thermal stability of γ-Fe2O3 was notably enhanced by HPMo grafting; thus, the magnetization of MoSx@γ-Fe2O3 hardly decreased during the application. The kinetic analysis indicates that the chemical adsorption of gaseous Hg0 was mainly dependent on the amounts of surface S22- and surface adsorption sites. Although the amount of S22- on sulfurated γ-Fe2O3 decreased after HPMo grafting, the amount of surface adsorption sites significantly increased due to the formation of a layered MoSx structure on the surface. Therefore, the ability of sulfurated γ-Fe2O3 to capture Hg0 was improved considerably after HPMo grafting. Furthermore, low concentrations of gaseous Hg0 in coal-fired flue gas can be gradually enriched by at least 1000 times by MoSx@γ-Fe2O3, which facilitates the recovery and centralized control of gaseous Hg0 in flue gas.

Remarkable improvement of Ti incorporation on Hg0 capture from smelting flue gas by sulfurated γ-Fe2O3: Performance and mechanism.

Except for the dangerous Boliden-Norzink technology, recovering gaseous Hg0 as liquid Hg0 using recyclable sorbents was an achievable method to control Hg0 emissions from smelting flue gas. In this study, Ti was incorporated into sulfurated γ-Fe2O3 to improve its performance for capturing Hg0 from smelting flue gas, and the mechanism of Ti incorporation on Hg0 adsorption onto sulfurated γ-Fe2O3 was investigated by comparing the kinetic parameters. The kinetic analysis showed that the Hg0 adsorption rate primarily depended on the amounts of surface adsorption sites for the physical adsorption of Hg0 and surface S22- for Hg0 oxidation. Since the amounts of both adsorption sites and S22- on sulfurated γ-Fe2O3 increased remarkably after Ti incorporation, Hg0 adsorption onto sulfurated γ-Fe2O3 was notably improved by 190-350%. The capacity of sulfurated Fe-Ti spinel for Hg0 capture could reach 48.6 mg g-1 and its average adsorption rate could reach 43.3 µg g-1 min-1 in 3 h. Meanwhile, the used sulfurated Fe-Ti spinel could be easily regenerated without any apparent degradation. Thus, sulfurated Fe-Ti spinel offered a significant advantage in recovering Hg0 from smelting flue gas.

Functions of pancreatic stellate cell-derived soluble factors in the microenvironment of pancreatic ductal carcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal forms of cancer with poor prognosis because it is highly resistant to traditional chemotherapy and radiotherapy and it has a low rate of surgical resection eligibility. Pancreatic stellate cells (PSC) have become a research hotspot in recent years, and play a vital role in PDAC microenvironment by secreting soluble factors such as transforming growth factor ß, interleukin-6, stromal cell-derived factor-1, hepatocyte growth factor and galectin-1. These PSC-derived cytokines and proteins contribute to PSC activation, participating in PDAC cell proliferation, migration, fibrosis, angiogenesis, immunosuppression, epithelial-mesenchymal transition, and chemoradiation resistance, leading to malignant outcome. Consequently, targeting these cytokines and proteins or their downstream signaling pathways is promising for treating PDAC.

Transgenic sperm produced by electrotransfection and allogeneic transplantation of chicken fetal spermatogonial stem cells.

To study self-renewal, genetic modification, and differentiation of avian spermatogonial stem cells (SSCs), we isolated chicken SSCs from fetal testes on the 16th hatching day via enzyme digestion, and then cultured the SSCs over 2 months after purification in vitro. SSCs were identified by alkaline phosphatase staining and SSEA-1 fluorescence. The EGFP gene was transfected into SSCs by three different methods: electroporation, liposome transfer and calcium acid phosphate precipitation. The transfection rate and cell survival rate using electroporation were higher than when using liposomes or calcium acid phosphate (20.52% vs. 9.75% and 5.61%; 69.86% vs. 65.00% and 51.16%, respectively). After selection with G418 for 8 days, the transgenic SSCs were transplanted into the testes of cocks treated with busulfan. Twenty-five days after transplantation, the recipients' semen was light ivory in color, and the density of spermatozoa was 3.87 (x10(7)/ml), with 4.25% expressing EGFP. By 85 days after transplantation, the number of spermatozoa increased to 32.7 (x10(7)/ml) and the rate of EGFP expression was 16.25%. Frozen sections of the recipients' testes showed that transgenic SSCs were located on the basal membrane of the seminiferous tubules and differentiated into spermatogenic cells at different stages. The EGFP gene was successfully amplified from the DNA of all recipients' semen samples.