516 research outputs found
Study on the Application of Biological Tactile in Fast Meat Freshness Detection
The author aimed to explore the application of biological tactile in fast non-destructive meat freshness detection. Used WDW-20 electronic universal testing machine, surveyed chicken, pork and beef the pressure characteristic curves, analysed respectively the relationship between the pressure characteristic curve parameters and the meat freshness. The author also analysed the relationship between the shape of pressure characteristic curve and the meat freshness. The results indicated that in the meal pressure characteristic curve, the curve shape and a number of mechanical parameters could reflect its freshness. Also, different types meat had different structures led them to the different mechanical properties; different types meat characteristic curves, the meat pressure characteristic curve shape and parameters reflected their fresh meat differently. Biological tactile can evaluate meat freshness in a few seconds. This is a promising, economic, simple and practicable way of fast meat freshness detection. Key words: Biological tactile; TVBN; pressure Characteristic curv
Light Harvesting Mechanism of Photosystem II in Photosynthesis:
As one of the most important chemical reactions on the earth, the photosynthetic reaction has gained much attention. For example, foliage and algae possess superior abilities to harvest luminous energy from sunlight in photosynthetic reactions by capturing lights with the light-harvesting complex (LHC) and transferring the energy from LHC to the reaction center (RC) in Photosystem II (PSII), to realize the continuous and efficient transformation from luminous energy to chemistry energy. In this article, the progresses in the studies on the crystal structure of PSII, the energy and electron transfer mechanism, and artificial simulation on photo-induced electron transfer are reviewed. Additionally, the initiating mechanism of hydrogen-abstraction photoinitiators, and the inspiration of the principles and mechanisms of photo-induced electron transfer in macromolecular photoinitiators were also discussed. It is believed that properly choosing covalent chains of appropriate types and length as the bridge between electron donor and electron acceptor is crucial for improving the initiating efficiency of photoinitiators. Keywords: photosynthesis; photosystem; light harvesting; photoinitiator; electron transfe
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Independent modulation of individual genomic component transcription and a cis-acting element related to high transcriptional activity in a multipartite DNA virus
Background: The genome of Banana bunchy top virus (BBTV) consists of at least six circular, single-stranded DNA components of 1kb in length. Some BBTV isolates may also carry satellite DNA molecules that are not essential for BBTV infection. The relation between multipartite DNA virus replication and their transcriptional levels and the underlying mechanism remain unclear. Results: To understand the coordinated replication and transcription of the multiple genomic components, the absolute amounts of each BBTV DNA component were measured by real-time PCR (qPCR), and their transcriptional levels were determined by RNAseq and reverse transcription-qPCR (qRT-PCR). Significant differences were found in the absolute amounts of individual BBTV genomic components. Transcriptional levels of each BBTV genomic component obtained from the RNAseq data matched closely to those obtained from qRT-PCR, but did not correspond to the absolute amount of each DNA component. The ratio of transcript over DNA copies ranged from 46.21 to 1059.44%, which was possibly regulated by the promoter region in the intergenic region of each component. To further determine this speculation, the promoter region of the DNA-S, -M or -N was constructed to the upstream of green fluorescent protein (GFP) gene for transient expression by agrobacterium-mediated transformation method. The qRT-PCR showed the highest transcriptional activity was promoted by DNA-N promoter, about 386.58% activity comparing with CaMV 35S promoter. Confocal microscopy observation showed that the intensity of green fluorescence was corresponding to that of qRT-PCR. Conclusions: Our data clearly showed that BBTV was able to control the transcriptional level of each DNA component independently by through the promoter sequences in the intergenic region. Moreover, a cis-acting element from DNA-N component had a high transcriptional activity.National Natural Science Foundation of China [31401709]; Hainan Provincial Natural Science Foundation [20153130]; Central Public-interest Scientific Institution Basal Research Fund for Chinese Academy of Tropical Agricultural Sciences [19CXTD-33]; Young Elite Scientists Sponsorship Program, CSTC [CSTC-QN201704]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Inhibition of GALR1 in PFC Alleviates Depressive-Like Behaviors in Postpartum Depression Rat Model by Upregulating CREB-BNDF and 5-HT Levels
Estrogen (E2) withdrawal is a core pathology mechanism for postpartum depression (PPD). Galanin (GAL), an estrogen-inducible neuropeptide has also been reported to be associated with depression. However, it still remains unclear which GAL receptors (GALRs) are involved in PPD pathologic process. In the present study, we discovered that the expression of GALR1, rather than GALR2/3, was upregulated with a region-specific pattern in the prefrontal cortex (PFC) of E2 withdrawal induced PPD model rats. Meanwhile, c-fos was also upregulated only in PFC in the same animal model. Injection of GALR1-siRNA into the bilateral PFC ameliorated depressive-like behavior of PPD rats, suggesting that the upregulation of GALR1 in PFC is involved in PPD. Moreover, Western Blot and HPLC assays demonstrated that the downregulation of CREB-BDNF signaling and 5-HT levels in the PFC of PPD rats were reversed after GALR1-siRNA injection. These comprehensive results suggest that the knock down of GALR1 in PFC alleviates depressive-like behaviors and reverse downregulation of CREB-BDNF and 5-HT levels in PPD rat model.HIGHLIGHTSÂ Expression level of GALR1 mRNA was significantly increased in PFC of estrogen withdraw-induced PPD rats.Injecting GALR1-siRNA into PFC alleviated depressive-like behavior and reversed the decrease of 5-HT level and CREB/BDNF signaling in PFC of PPD rats
Recent advances in clay mineral-containing nanocomposite hydrogels
Clay mineral-containing nanocomposite hydrogels have been proven to have exceptional composition,
properties, and applications, and consequently have attracted a significant amount of research effort
over the past few years. The objective of this paper is to summarize and evaluate scientific advances in
clay mineral-containing nanocomposite hydrogels in terms of their specific preparation, formation
mechanisms, properties, and applications, and to identify the prevailing challenges and future directions
in the field. The state-of-the-art of existing technologies and insights into the exfoliation of layered clay
minerals, in particular montmorillonite and LAPONITEs, are discussed first. The formation and structural
characteristics of polymer/clay nanocomposite hydrogels made from in situ free radical polymerization,
supramolecular assembly, and freezing–thawing cycles are then examined. Studies indicate that additional
hydrogen bonding, electrostatic interactions, coordination bonds, hydrophobic interaction, and even covalent
bonds could occur between the clay mineral nanoplatelets and polymer chains, thereby leading to
the formation of unique three-dimensional networks. Accordingly, the hydrogels exhibit exceptional
optical and mechanical properties, swelling–deswelling behavior, and stimuli-responsiveness, reflecting the
remarkable effects of clay minerals. With the pivotal roles of clay minerals in clay mineral-containing
nanocomposite hydrogels, the nanocomposite hydrogels possess great potential as superabsorbents, drug
vehicles, tissue scaffolds, wound dressing, and biosensors. Future studies should lay emphasis on the
formation mechanisms with in-depth insights into interfacial interactions, the tactical functionalization of
clay minerals and polymers for desired properties, and expanding of their applications
A high-density genetic map and QTL mapping of leaf traits and glucosinolates in <i>Barbarea vulgaris</i>
Electrochemical CO2 reduction on Cu and Au electrodes studied using in situ sum frequency generation spectroscopy.
As an important pathway for energy storage and a key reaction in the carbon cycle, the CO2 electrochemical reduction reaction has recently gained significant interest. A variety of catalysts have been used to approach this topic experimentally and theoretically; however, the molecular level insight into the reaction mechanism is lacking due to the complexity of the surface processes and the challenges in probing the intermediate species. In this study, CO2 reduction reactions on polycrystalline Cu and Au electrodes were investigated in 0.1 M CO2-saturated NaHCO3 solution. In situ sum frequency generation (SFG) spectroscopy has been adopted to access the intermediates and products on the metal electrodes. On the Au electrode, only linearly adsorbed CO could be detected, and the reduction produced no hydrocarbon species. On the Cu electrode, C-H stretching vibrations corresponding to surface-adsorbed ethoxy species were observed, but no CO vibrations can be detected with SFG. The results revealed that the CO randomly adsorbed on the Cu surface, and the multiple orientations of the adsorbed species may be the reason for the formation of C-C bonding. These results demonstrate direct molecular level evidence for different reaction pathways on the Cu and Au electrodes
Is Epstein-Barr Virus Infection Associated With Thyroid Tumorigenesis?—A Southern China Cohort Study
Background: Epstein-Barr virus (EBV) is associated with many epithelial malignancies. A few reports on the association between EBV and thyroid tumorigenesis have been investigated. However, the conclusion is highly contradictory. We aimed to explore the role of EBV in thyroid nodule development and its clinical significance in a cohort from southern China.Method: We conducted a retrospective data abstraction study of patients who underwent thyroidectomy between December 2017 and June 2018. We retrospectively analyzed the clinicopathological parameters and EBV infection status (serological antibodies and in situ hybridization).Result: The cohort comprised 384 patients with newly diagnosed thyroid diseases, including 261 papillary thyroid carcinomas, 87 nodular goiters, 21 follicular adenomas, 12 follicular thyroid carcinomas, and 3 medullary thyroid carcinomas. Forty-two (10.9%) patients were identified as being serological antibody positive. However, there was no association between the clinicopathological parameters and serological antibody positivity. Additionally, none of the patients showed EBER expression in thyroid normal/cancer cell nuclei in in situ hybridization.Conclusion: In this study, no correlation between EBV and thyroid diseases was found in a cohort from southern China
HLA-matched sibling transplantation with G-CSF mobilized PBSCs and BM decreases GVHD in adult patients with severe aplastic anemia
<p>Abstract</p> <p>Background</p> <p>Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective treatment for severe aplastic anemia (SAA). However, graft failure and graft-versus-host disease (GVHD) are major causes of the early morbidity in Allo-HSCT.</p> <p>Methods</p> <p>To reduce graft failure and GVHD, we treated fifteen patients with SAA using high- dose of HSCT with both G-CSF mobilized PB and BMSCs from HLA-identical siblings to treat patients with SAA.</p> <p>Results</p> <p>All patients had successful bone marrow engraftment. Only one patient had late rejection. Median time to ANC greater than 0.5 Ă— 10<sup>9</sup>/L and platelet counts greater than 20 Ă— 10<sup>9</sup>/L was 12 and 16.5 days, respectively. No acute GVHD was observed. The incidence of chronic GVHD was 6.67%. The total three-year probability of disease-free survival was 79.8%.</p> <p>Conclusion</p> <p>HSCT with both G-CSF mobilized PB and BMSCs is a promising approach for heavily transfused and/or allo-immunized patients with SAA.</p
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