Trophic strategy of diverse methanogens across a river-to-sea gradient

Methanogens are an important biogenic source of methane, especially in estuarine waters across a river-to-sea gradient. However, the diversity and trophic strategy of methanogens in this gradient are not clear. In this study, the diversity and trophic strategy of methanogens in sediments across the Yellow River (YR) to the Bohai Sea (BS) gradient were investigated by high-throughput sequencing based on the 16S rRNA gene. The results showed that the diversity of methanogens in sediments varied from multitrophic communities in YR samples to specific methylotrophic communities in BS samples. The methanogenic community in YR samples was dominated by Methanosarcina, while that of BS samples was dominated by methylotrophic Methanococcoides. The distinct methanogens suggested that the methanogenic community of BS sediments did not originate from YR sediment input. High-throughput sequencing of the mcrA gene revealed that active Methanococcoides dominated in the BS enrichment cultures with trimethylamine as the substrate, and methylotrophic Methanolobus dominated in the YR enrichment cultures, as detected to a limited amount in in situ sediment samples. Methanosarcina were also detected in this gradient sample. Furthermore, the same species of Methanosarcina mazei, which was widely distributed, was isolated from the area across a river-to-sea gradient by the culture-dependent method. In summary, our results showed that a distribution of diverse methanogens across a river-to-sea gradient may shed light on adaption strategies and survival mechanisms in methanogens

Optimization of RAPD-PCR reaction system for genetic relationships analysis of 15 camellia cultivars

With orthogonal analysis by L27(36), the random amplified polymorphic DNA (RAPD)-PCR optimization reaction system for camellia were obtained. Results showed that the optimization system was 10×PCR Buffer (2.5 L), 25 mM MgCl2 (2.5 L), 2.5 mM dNTPs (2.0 L), 20 M primer (1.0 L), Tag (1.5 U), temple DNA (40 ng or so) and added ddH2O to the total volume 25 uL; suitable annealing temperature was 36°C. With the optimized system and fifteen 10 nt random primers, we analyzed 15 camellia cultivars and observed 102 clear amplified loci, in which polymorphic loci were 79 while the percentage of polymorphic loci were 77.54%. Cluster analysis showed that the four groups were divided at the point 0.75 of similarity coefficient, indicating relatively high genetic diversity. We also found that the gene controlling petal color may play an important role in RAPD analysis. Moreover, genetic diversities based on RAPD analysis could be clearly reflected by morphological traits among 15 camellia cultivars. This study showed the RAPD optimization system was suitable and RAPD molecular marker was effective and useful tool for detection of genetic relationships among camellia cultivars

Influence of building directions on the impact properties of NiTi fabricated via laser powder bed fusion

The Charpy impact toughness is a crucial mechanical parameter in the application of materials within the realm of engineering. This study represents the pioneering investigation into the influence of different building directions on the Charpy impact toughness of NiTi shape memory alloys (SMAs) produced via laser powder bed fusion (LPBF). Texture analysis reveals that C0 and C90 exhibit a pronounced // building direction (BA), while C45 demonstrates a strong texture along and . The impact test results demonstrate that C0 exhibits superior impact toughness with an absorbed energy of 12.87 J. The fractured surfaces are examined using the scanning electron microscope (SEM) and transmission electron microscope (TEM). Among them, the electron backscatter diffraction (EBSD) results indicate that the samples with higher geometrically necessary dislocation (GND) and kernel average misorientation (KAM) values can effectively reflect superior impact toughness. In contrast, fewer high-angle grain boundaries (HAGBs) are preferable. Due to the adiabatic effect, the phase transformation of the samples from austenite to martensite doesn't appear under the impact loading. Additionally, this paper discusses the impact of texture orientation, defects, and the relationship between loading direction and deposited layers on the impact toughness of the samples. These findings on impact properties would provide valuable guidance for engineering applications of NiTi SMAs

Tetrandrine, an activator of autophagy, induces autophagic cell death via PKC-α inhibition and mTOR-dependent mechanisms.

Emerging evidence suggests the therapeutic role of autophagic modulators in cancer therapy. This study aims to identify novel traditional Chinese medicinal herbs as potential anti-tumor agents through autophagic induction, which finally lead to autophagy mediated-cell death in apoptosis-resistant cancer cells. Using bioactivity-guided purification, we identified tetrandrine (Tet) from herbal plant, Radix stephaniae tetrandrae, as an inducer of autophagy. Across a number of cancer cell lines, we found that breast cancer cells treated with tetrandrine show an increase autophagic flux and formation of autophagosomes. In addition, tetrandrine induces cell death in a panel of apoptosis-resistant cell lines that are deficient for caspase 3, caspase 7, caspase 3 and 7, or Bax-Bak respectively. We also showed that tetrandrine-induced cell death is independent of necrotic cell death. Mechanistically, tetrandrine induces autophagy that depends on mTOR inactivation. Furthermore, tetrandrine induces autophagy in a calcium/calmodulin-dependent protein kinase kinase-β (CaMKK-β), 5′ AMP-activated protein kinase (AMPK) independent manner. Finally, by kinase profiling against 300 WT kinases and computational molecular docking analysis, we showed that tetrandrine is a novel PKC-α inhibitor, which lead to autophagic induction through PKC-α inactivation. This study provides detailed insights into the novel cytotoxic mechanism of an anti-tumor compound originated from the herbal plant, which may be useful in promoting autophagy mediated- cell death in cancer cell that is resistant to apoptosis.published_or_final_versio

A Hybrid Time-Scaling Transformation for Time-Delay Optimal Control Problems

In this paper, we consider a class of nonlinear time-delay optimal control problems with canonical equality and inequality constraints. We propose a new computational approach, which combines the control parameterization technique with a hybrid time-scaling strategy, for solving this class of optimal control problems. The proposed approach involves approximating the control variables by piecewise constant functions, whose heights and switching times are decision variables to be optimized. Then, the resulting problem with varying switching times is transformed, via a new hybrid time-scaling strategy, into an equivalent problem with fixed switching times, which is much preferred for numerical computation. Our new time-scaling strategy is hybrid in the sense that it is related to two coupled time-delay systems—one defined on the original time scale, in which the switching times are variable, the other defined on the new time scale, in which the switching times are fixed. This is different from the conventional time-scaling transformation widely used in the literature, which is not applicable to systems with time-delays. To demonstrate the effectiveness of the proposed approach, we solve four numerical examples. The results show that the costs obtained by our new approach are lower, when compared with those obtained by existing optimal control methods

Preparation and characterization of collagen-chitosan composites

In this article, nature derived collagen was mixed with chitosan and crosslinked by formaldehyde to form a homogeneous composite membrane. The microstructure of the composite was characterized by transmission electron microscopy and differential scanning calorimetry. Mechanical and swelling properties of the composite were improved compared with pure collagen and can be modulated via changing the crosslinking conditions, such as pH, time, and concentration. (C) 1997 John Wiley & Sons, Inc

Fabrication of silicon-on-reflector for Si-based resonant-cavity-enhanced photodetectors

A novel silicon-on-reflector substrate for Si-based resonant-cavity-enhanced photodetectors has been fabricated by using Si-based sol-gel and smart-cut techniques. The Si/SiO2 Bragg reflector is controlled in situ by electron beam evaporation and the thickness can be adjusted to get high reflectivity. The reflectance spectra of the silicon-on-reflector substrate with five pairs of Si/SiO2 reflector have been measured and simulated by transfer matrix model. The reflectivity at operating wavelength is close to 100%. Based on the silicon-on-reflector substrate, SiGe/Si multiple quantum wells resonant-cavity-enhanced photodetectors for 1.3 mu m wavelength have been designed and simulated. Ten-fold enhancement of the quantum efficiency of resonant-cavity-enhanced photodetectors compared with conventional photodetectors is predicted

FTO influences adipogenesis by regulating mitotic clonal expansion

The fat mass and obesity-associated (FTO) gene plays a pivotal role in regulating body weight and fat mass; however, the underlying mechanisms are poorly understood. Here we show that primary adipocytes and mouse embryonic fibroblasts (MEFs) derived from FTO overexpression (FTO-4) mice exhibit increased potential for adipogenic differentiation, while MEFs derived from FTO knockout (FTO-KO) mice show reduced adipogenesis. As predicted from these findings, fat pads from FTO-4 mice fed a high-fat diet show more numerous adipocytes. FTO influences adipogenesis by regulating events early in adipogenesis, during the process of mitotic clonal expansion. The effect of FTO on adipogenesis appears to be mediated via enhanced expression of the pro-adipogenic short isoform of RUNX1T1, which enhanced adipocyte proliferation, and is increased in FTO-4 MEFs and reduced in FTO-KO MEFs. Our findings provide novel mechanistic insight into how upregulation of FTO leads to obesity

DSG2 and c-MYC Interact to Regulate the Expression of ADAM17 and Promote the Development of Cervical Cancer

Li-Mian Song,1,&ast; Du-Juan Yao,1,&ast; Lin Xia,1 Xu-Ming Wang,2 Tian Liu,2 Qian-Qian Tang,1 Jun Zhou1 1Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People’s Republic of China; 2Department of Pathology, Affiliated Hospital of Guilin Medical College, Guilin, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Jun Zhou, Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People’s Republic of China, Email [email protected]: To explore the effect of DSG2 on the growth of cervical cancer cells and its possible regulatory mechanism.Methods: The expression levels and survival prognosis of DSG2 and ADAM17 in cervical squamous cell carcinoma tissues and adjacent normal tissues were analyzed by bioinformatics. CCK-8 assay, colony formation assay and Transwell assay were used to detect the effects of DSG2 on the proliferative activity, colony formation ability and migration ability of SiHa and Hela cells. The effect of DSG 2 on the level of ADAM17 transcription and translation was detected by qPCR and Western blot experiments. The interaction between DSG2 and c-MYC was detected by immunocoprecipitation. c-MYC inhibitors were used in HeLa cells overexpressing DSG2 to analyze the effects of DSG2 and c-MYC on proliferation, colony formation and migration of Hela cells, as well as the regulation of ADAM17 expression.Results: DSG2 was highly expressed in cervical squamous cell carcinoma compared with normal tissues (P< 0.05), and high DSG2 expression suggested poor overall survival (P< 0.05). After DSG2 knockdown, the proliferative activity, colony formation and migration ability of SiHa and Hela cells were significantly decreased (P< 0.05). Compared with adjacent normal tissues, ADAM17 was highly expressed in cervical squamous cell carcinoma (P< 0.05), and high ADAM17 expression suggested poor overall survival in cervical cancer patients (P< 0.05). The results of immunocoprecipitation showed the interaction between DSG2 and c-MYC. Compared with DSG2 overexpression group, DSG2 overexpression combined with c-MYC inhibition group significantly decreased cell proliferation, migration and ADAM17 expression (P < 0.05).Conclusion: DSG2 is highly expressed in cervical cancer, and inhibition of DSG2 expression can reduce the proliferation and migration ability of cervical cancer cells, which may be related to the regulation of ADAM17 expression through c-MYC interaction.Keywords: cervical cancer, proliferation, migration, DSG2, c-MYC, ADAM1

Tumor Cell-Derived Exosomal Hybrid Nanosystems Loaded with Rhubarbic Acid and Tanshinone IIA for Sepsis Treatment

Qian Wu,1,&ast; Qing-Qing Dong,1,&ast; Si-Hui Wang,1 Yi Lu,1 Yi Shi,1 Xiao-Ling Xu,2 Wei Chen1 1ICU, Longhua Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, People’s Republic of China; 2Shulan International Medical College, Zhejiang Shuren University, Hangzhou, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Wei Chen, Longhua Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, 725 South WanPing Road, Shanghai, 200032, People’s Republic of China, Tel +86-21-64385700-3522, Email [email protected] Xiao-Ling Xu, Shulan International Medical College, Zhejiang Shuren University, 8 Shuren Street, Hangzhou, 310015, People’s Republic of China, Email [email protected]: Sepsis continues to exert a significant impact on morbidity and mortality in clinical settings, with immunosuppression, multi-organ failure, and disruptions in gut microbiota being key features. Although rheinic acid and tanshinone IIA show promise in mitigating macrophage apoptosis in sepsis treatment, their precise targeting of macrophages remains limited. Additionally, the evaluation of intestinal flora changes following treatment, which plays a significant role in subsequent cytokine storms, has been overlooked. Leveraging the innate inflammation chemotaxis of tumor cell-derived exosomes allows for their rapid recognition and uptake by activated macrophages, facilitating phenotypic changes and harnessing anti-inflammatory effects.Methods: We extracted exosomes from H1299 cells using a precipitation method. Then we developed a tumor cell-derived exosomal hybrid nanosystem loaded with rhubarbic acid and tanshinone IIA (R+T/Lipo/EXO) for sepsis treatment. In vitro studies, we verify the anti-inflammatory effect and the mechanism of inhibiting cell apoptosis of nano drug delivery system. The anti-inflammatory effects, safety, and modulation of intestinal microbiota by the nanoformulations were further validated in the in vivo study.Results: Nanoformulation demonstrated enhanced macrophage internalization, reduced TNF-α expression, inhibited apoptosis, modulated intestinal flora, and alleviated immunosuppression.Conclusion: R+T/Lipo/EXO presents a promising approach using exosomal hybrid nanosystems for treating sepsis. Keywords: sepsis, rheinic acid, tanshinone IIA, exosome, hybrid nanosyste