Search

Summary: Softening in fruit adversely impacts their edible quality and commercial value, leading to substantial economic losses during fruit ripening, long‐term storage, long‐distance transportation, and marketing. As the apple fruit demonstrates climacteric respiration, its firmness decreases with increasing ethylene release rate during fruit ripening and postharvest storage. However, the molecular mechanisms underlying ethylene‐mediated regulation of fruit softening in apple remain poorly understood. In this study, we identified a WRKY transcription factor (TF) MdWRKY31, which is repressed by ethylene treatment. Using transgenic approaches, we found that overexpression of MdWRKY31 delays softening by negatively regulating xyloglucan endotransglucosylase/hydrolases 2 (MdXTH2) expression. Yeast one‐hybrid (Y1H), electrophoretic mobility shift (EMSA), and dual‐luciferase assays further suggested that MdWRKY31 directly binds to the MdXTH2 promoter via a W‐box element and represses its transcription. Transient overexpression of ethylene‐induced MdNAC7, a NAC TF, in apple fruit promoted softening by decreasing cellulose content and increasing water‐soluble pectin content in fruit. MdNAC7 interacted with MdWRKY31 to form a protein complex, and their interaction decreased the transcriptional repression of MdWRKY31 on MdXTH2. Furthermore, MdNAC7 does not directly regulate MdXTH2 expression, but the protein complex formed with MdWRKY31 hinders MdWRKY31 from binding to the promoter of MdXTH2. Our findings underscore the significance of the regulatory complex NAC7–WRKY31 in ethylene‐responsive signalling, connecting the ethylene signal to XTH2 expression to promote fruit softening. This sheds light on the intricate mechanisms governing apple fruit firmness and opens avenues for enhancing fruit quality and reducing economic losses associated with softening. [ABSTRACT FROM AUTHOR]

Summary: In wireless charging systems for electric vehicles, fluctuations in coil mutual inductance can affect both system output power and efficiency. This paper introduces a coil mutual inductance model that accounts for metal shielding material. The formula for coil mutual inductance is derived using Maxwell's equations and boundary conditions. Additionally, the paper presents a tactic for adapting the mutual inductance with the aid of an intelligent optimization algorithm, which is utilized for steadying the mutual inductance of the transmission coil. Lastly, a model of the transmission coil is developed to authenticate the practicality of the mutual inductance equation and the adaptation scheme. Measurement and calculation results indicate that the difference between the calculated value of the mutual inductance formula and the actual mutual inductance value of the coil, following deflection and offset, is below 5%. Moreover, the algorithm, along with the employed adaptation strategy, consistently demonstrates effectiveness in maintaining the mutual inductance value within a predefined range. The temporal efficiency of the algorithm, as measured by the time taken to determine this coordinate position, is consistently under 1 s. This ensures that the algorithm exhibits a rapid response time, a crucial attribute in ensuring its practical utility. [ABSTRACT FROM AUTHOR]

SUMMARY: Drought stress is one of the dominating challenges to the growth and productivity in crop plants. Elucidating the molecular mechanisms of plants responses to drought stress is fundamental to improve fruit quality. However, such molecular mechanisms are poorly understood in apple (Malus domestica Borkh.). In this study, we explored that the BTB‐BACK‐TAZ protein, MdBT2, negatively modulates the drought tolerance of apple plantlets. Moreover, we identified a novel Homeodomain‐leucine zipper (HD‐Zip) transcription factor, MdHDZ27, using a yeast two‐hybrid (Y2H) screen with MdBT2 as the bait. Overexpression of MdHDZ27 in apple plantlets, calli, and tomato plantlets enhanced their drought tolerance by promoting the expression of drought tolerance‐related genes [responsive to dehydration 29A (MdRD29A) and MdRD29B]. Biochemical analyses demonstrated that MdHDZ27 directly binds to and activates the promoters of MdRD29A and MdRD29B. Furthermore, in vitro and in vivo assays indicate that MdBT2 interacts with and ubiquitinates MdHDZ27, via the ubiquitin/26S proteasome pathway. This ubiquitination results in the degradation of MdHDZ27 and weakens the transcriptional activation of MdHDZ27 on MdRD29A and MdRD29B. Finally, a series of transgenic analyses in apple plantlets further clarified the role of the relationship between MdBT2 and MdHDZ27, as well as the effect of their interaction on drought resistance in apple plantlets. Collectively, our findings reveal a novel mechanism by which the MdBT2‐MdHDZ27 regulatory module controls drought tolerance, which is of great significance for enhancing the drought resistance of apple and other plants. Significance Statement: Collectively, our findings clearly decipher a novel regulatory network for drought tolerance in the apple plant, which centers on the regulatory module MdBT2‐MdHDZ27 and its roles in transcriptional regulation and post‐transcriptional modification, which will be useful for improving the drought tolerances of apple and other economically important plant species. [ABSTRACT FROM AUTHOR]

Three-dimensional inversion based on source growing uses systematic searches. Compared with the regularization inversion, this method has lower computational requirements and faster processing speed. The criteria determining the source growth is crucial for the quality of the results. This study proposes an inversion based on source growing with full-tensor gravity gradiometry data to improve vertical inversion effectiveness. First, a depth weighting function is introduced for the criteria to optimize the determination of source growing at different depths. Second, the weights of different data are adjusted based on the inversion results of single-component gradient data, and a joint inversion method is established. Finally, matrix compression reduces memory occupation and improves computational efficiency. By the tests of synthetic data and real data from Vinton Dome, it is demonstrated that the proposed method can effectively guide source growing, providing stronger ability for distinguishing deep targets and being suitable for the inversion of complex-shaped targets. Furthermore, the method has high computational efficiency and anti-noise ability. [ABSTRACT FROM AUTHOR]

A systematic density functional theory study, including 17 exchange–correlation functionals, was performed on 22 composite structures consisting of organic molecules, e.g., ethylene, ethane, and benzene, and superhalogen substitutions arising from [MgX3]− and [Mg2X5]− (X = F, Cl). Range-separated hybrid functionals ω B97M-V, ω B97X-D3(BJ), ω B97XD, ω B97X, and CAM-B3LYP, as well as double-hybrid functionals B2PLYP and DSD-PBEP86-D3(BJ), are verified to provide reliable results with accuracy approaching that at the coupled-cluster single double triple [CCSD(T)] level. The basis set effect of density functional theory calculation is usually moderate, and triple-ξ quality, e.g., Def2-TZVP, is enough in most cases. In addition, the average values from HF and MP2 method, indicated as (MP2 + HF)/2, are also quite close to those of CCSD(T). [ABSTRACT FROM AUTHOR]

In this paper, we solve the question completely raised by Feng Qi and Dongkyu Lim in paper "Monotonicity properties for a ratio of finite many gamma functions" published in Advances in Difference Equations and get some properties about ratios of finitely many gamma functions such as complete monotonicity, logarithmically complete monotonicity, the Bernstein function property, null point and extreme value. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central South University is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Biannual Ultrasound showed insufficient sensitivity in detecting small or early-stage hepatocellular carcinoma (HCC). Abbreviated magnetic resonance imaging (A-MRI) protocols with fewer sequences demonstrated higher HCC detection sensitivity than ultrasound with acceptable cost and examination time. Purpose: To compare the diagnostic performance of gadoxetic acid-enhanced A-MRI with a full sequence MRI (F-MRI) protocol for small HCC (≤2 cm) in cirrhotic or hepatitis B virus-infected high-risk patients. Material and Methods: Two hundred and four consecutive patients with 166 pathologically confirmed small HCC who underwent preoperative gadoxetic acid-enhanced MRI were retrospectively included. A-MRI set comprised T1-weighted hepatobiliary phase imaging, T2-weighted imaging, diffusion-weighted imaging and apparent diffusion coefficient mapping. Two independent radiologists blinded to clinical data assessed the A-MRI set and F-MRI set. Per-patient HCC and per-lesion HCC diagnostic performance were compared. Results: Per-patient HCC detection sensitivity of A-MRI set was 93.8% and 91.2% for observer 1 and observer 2, and, for the F-MRI set, the per-patient HCC detection sensitivity was 96.6% and 95.2%, respectively. There was no significant difference in per-patient sensitivity, specificity and per-lesion HCC detection sensitivity between the two imaging sets for both readers. (P = 0.06–0.25) The A-MRI set showed higher sensitivity on HCC without arterial phase hyperenhancement, and the F-MRI set demonstrated with higher sensitivity on HCC with arterial phase hyperenhancement (P < 0.05). Conclusion: A-MRI using diagnostic criteria including hypointensity on hepatobiliary phase plus mild to moderate hyperintensity on T2-weighted imaging or restricted diffusion demonstrated comparable sensitivity and specificity for small HCC compared to the F-MRI protocol in high-risk patients. [ABSTRACT FROM AUTHOR]

Summary: Malic acid accumulation in the vacuole largely determines acidity and perception of sweetness of apple. It has long been observed that reduction in malate level is associated with increase in ethylene production during the ripening process of climacteric fruits, but the molecular mechanism linking ethylene to malate reduction is unclear.Here, we show that ethylene‐modulated WRKY transcription factor 31 (WRKY31)–Ethylene Response Factor 72 (ERF72)–ALUMINUM ACTIVATED MALATE TRANSPORTER 9 (Ma1) network regulates malate accumulation in apple fruit.ERF72 binds to the promoter of ALMT9, a key tonoplast transporter for malate accumulation of apple, transcriptionally repressing ALMT9 expression in response to ethylene. WRKY31 interacts with ERF72, suppressing its transcriptional inhibition activity on ALMT9. In addition, WRKY31 directly binds to the promoters of ERF72 and ALMT9, transcriptionally repressing and activating ERF72 and ALMT9, respectively. The expression of WRKY31 decreases in response to ethylene, lowering the transcription of ALMT9 directly and via its interactions with ERF72.These findings reveal that the regulatory complex WRKY31 forms with ERF72 responds to ethylene, linking the ethylene signal to ALMT9 expression in reducing malate transport into the vacuole during fruit ripening. See also the Commentary on this article by Martinoia & Neuhaus, 239: 821–823. [ABSTRACT FROM AUTHOR]

The rapidly increasing use of high-throughput screening had produced a plethora of expanding knowledge on the molecular basis of natural killer/T-cell lymphoma (NKTCL), which in turn has revolutionized the treatment. Specifically, the use of asparaginase-containing regimens has led to substantial improvement in survival outcomes in NKTCL patients. Novel treatment strategies that are currently under development include cell-surface-targeted antibodies, immune checkpoint inhibitors, Epstein-Barr virus targeted cytotoxic T lymphocyte, immunomodulatory agents, chimeric antigen receptor T cells, signaling pathway inhibitors and epigenetic targeted agents. In almost all cases, initial clinical studies of newly developed treatment are conducted in patients relapsed, and refractory NKTCL due to very limited treatment options. This review summarizes the results of these novel treatments for NKTCL and discusses their potential for likely use in NKTCL in a wider setting in the future. [ABSTRACT FROM AUTHOR]

Objectives: Postoperative neurological deficits remain a challenge in cardiac surgery employing deep hypothermic circulatory arrest (DHCA). This study aimed to investigate the effect of WIN55, 212-2, a cannabinoid agonist, on brain injury in a rat model of DHCA. Methods: Twenty-four male Sprague Dawley rats were randomly divided into three groups: a control group (which underwent cardiopulmonary bypass (CPB) only), a DHCA group (CPB with DHCA), and a WIN group (WIN55, 212-2 pretreatment before CPB with DHCA). Histopathological changes in the brain were evaluated by hematoxylin–eosin staining. Plasma levels of superoxide dismutase (SOD) and proinflammatory cytokines including interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha (TNF-a) were determined using an enzyme-linked immunosorbent assay (ELISA). The expression of SOD in the hippocampus was detected by Western blot and immunofluorescence staining. Levels of apoptotic-related protein caspase-3 and type 1 cannabinoid receptor (CB1R) in the hippocampus were evaluated by Western blot. Results: WIN55, 212-2 administration attenuated histopathological injury of the hippocampus in rats undergoing DHCA, associated with lowered levels of IL-1β, IL-6, and TNF-α (p < 0.05, p < 0.001, and p < 0.01, vs. DHCA, respectively) and an increased level of SOD (p < 0.05 vs. DHCA). WIN55, 212-2 treatment also increased the content of SOD in the hippocampus. The protein expression of caspase-3 was downregulated and the expression of CB1R was upregulated in the hippocampus by WIN55, 212-2. Conclusions: the administration of WIN55, 212-2 alleviates hippocampal injury induced by DHCA in rats by regulating intrinsic inflammatory and oxidative stress responses through a CB1R-dependent mechanism. [ABSTRACT FROM AUTHOR]

In the North China Plain, the excessive application of nitrogen (N) fertilizer for ensuring high yield and a single application at sowing for simplifying management in farmer practice lead to low N use efficiency and environmental risk in maize (Zea mays L.) production. However, it is unclear whether and how late split application with a lower level of N fertilizer influences maize yield. To address this question, a two-year field experiment was conducted with two commercial maize cultivars (Zhengdan 958 and Denghai 605) using a lower level of N input (180 kg ha−1) by setting up single application at sowing and split application at sowing and later stages (V12, R1, and R2) with four different ratios, respectively. The maize yield with split-applied 180 kg ha−1 N did not decrease compared to the average yield with 240 kg ha−1 N input in farmer practice, while it increased by 6.7% to 11.5% in the four N split-application treatments compared with that of the single-application control. Morphological and physiological analyses demonstrated that late split application of N (i) increased the net photosynthetic rate and chlorophyll content and thus promoted the photosynthetic efficiency during the reproductive stages; (ii) promoted the sink capacity via improved kernel number, endosperm cells division, and grain-filling rate; and (iii) increased the final N content and N efficiency in the plant. Therefore, we propose that late split application of N could reduce N fertilizer input and coordinately improve N efficiency and grain yield in summer maize production, which are likely achieved by optimizing the source–sink relations during the grain-filling stage. [ABSTRACT FROM AUTHOR]

Chronic nonbacterial prostatitis (CNP),also the type III prostatitis account for more than 90% of all patients with prostatitis. It has a long course of disease, easy to repeat, unknown pathogenesis and poor clinical efficacy. At present, some scholars at home and abroad have found that there is differential expression of microRNA(miRNA) in prostatic fluid of CNP patients or prostate tissue of CNP rat model. Intervention of miRNA expression can alleviate the symptoms and pharmacodynamics of CNP to a certain extent, which opens up a new way and direction for the pathogenesis and diagnosis and treatment of CNP. Therefore, this paper reviews the research progress of miRNA and CNP in recent years. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effect of curcumol on NOD-like receptor thermoprotein domain 3 (NLRP3) inflammasomes, and analyze the mechanism underlying curcumol against liver fibrosis. Methods: Thirty Kunming mice were divided into a control group, a model group and a curcumol group according to a random number table, 10 mice in each group. Mice were intraperitoneally injected with 40% carbon tetrachloride (CCl4:peanut oil, 2:3 preparation) at 5 mL/kg for 6 weeks, twice a week, for developing a liver fibrosis model. The mice in the control group were given the same amount of peanut oil twice a week for 6 weeks. The mice in the curcumol group were given curcumol (30 mL/kg) intragastrically, and the mice in the model and control groups were given the same amount of normal saline once a day for 6 weeks. Changes in liver structure were observed by hematoxylin and eosin (HE) and Masson staining. Liver function, liver fiber indices, and the expression of interleukin (IL)-10 and tumor necrosis factor-α (TNF-α) levels were determined by automatic biochemical analyzer and enzyme linked immunosorbent assay kit. Immunoblotting and reverse transcription-quantitative PCR (RT-qPCR) were performed to detect the expression of NLRP3 inflammasome-related molecules, TGF-β and collagen. Results: HE and Masson staining results showed that the hepatocytes of the model group were arranged irregularly with pseudo-lobular structure and a large amount of collagen deposition. The mice in the curcumol group had a significant decrease in liver function and liver fibers indices compared with the model group (P<0.05); RT-qPCR and Western blotting results reveal that, in the curcumol group, the mRNA and protein expression levels of NLRP3, IL-1 β, Caspase 1 and gasdermin D decreased significantly compared with the model group (P<0.05); immunohistochemical results showed that in the curcumol group, the protein expression levels of NLRP3 and IL-1 β decreased significantly compared with the model group (P<0.05). Conclusion: A potential anti-liver fibrosis mechanism of curcumol may be associated with the inhibition of NLRP3 inflammasomes and decreasing the downstream inflammatory response. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to investigate the associations of osteosarcopenic obesity (OSO) and its components with complete blood cell count-derived inflammation indices.Methods: In this cross-sectional study, data of 648 participants aged ≥60 years (men/women: 232/416, mean age: 67.21 ± 6.40 years) were collected from January 2018 to December 2020. Areal bone mineral density and body fat percentage were used to define osteopenia/osteoporosis and obesity, respectively. The criteria of the 2019 Asian Working Group for Sarcopenia were used to diagnose sarcopenia. Based on the number of these conditions, participants were divided into four groups: OSO/0, OSO/1, OSO/2, and OSO/3. Logistic regression analysis was conducted to identify associations between blood cell count-derived inflammation indices and the number of disorders with abnormal body composition.Results: Systemic inflammation response index (SIRI), white blood cells, neutrophil-to-lymphocyte ratio (NLR), aggregate inflammation systemic index (AISI), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) showed statistically significant differences among the four groups (P < 0.05). Unlike in the OSO/0 group, in all other groups, AISI, SIRI, PLR, and NLR were significantly associated with increased likelihood of having multiple disorders with abnormal body composition after adjustment for confounders (P < 0.0001 for all). However, LMR showed an inverse correlation with the number of these conditions (P < 0.05).Conclusion: Higher SIRI, AISI, NLR, and PLR values and lower LMR values are closely associated with OSO and its individual components-osteoporosis, sarcopenia, and obesity-in older adults, suggesting that the value of these indices in the evaluation of OSO warrants further investigation. [ABSTRACT FROM AUTHOR]

Depression can be a non-motor symptom, a risk factor, and even a co-morbidity of Parkinson's disease (PD). In either case, depression seriously affects the quality of life of PD patients. Unfortunately, at present, a large number of clinical and basic studies focused on the pathophysiological mechanism of PD and the prevention and treatment of motor symptoms. Although there has been increasing attention to PD-related depression, it is difficult to achieve early detection and early intervention, because the clinical guidelines mostly refer to depression developed after or accompanied by motor impairments. Why is there such a dilemma? This is because there has been no suitable preclinical animal model for studying the relationship between depression and PD, and the assessment of depressive behavior in PD preclinical models is as well a very challenging task since it is not free from the confounding from the motor impairment. As a common method to simulate PD symptoms, neurotoxin-induced PD models have been widely used. Studies have found that neurotoxin-induced PD model animals could exhibit depression-like behaviors, which sometimes manifested earlier than motor impairments. Therefore, there have been attempts to establish the PD-related depression model by neurotoxin induction. However, due to a lack of unified protocol, the reported results were diverse. For the purpose of further promoting the improvement and optimization of the animal models and the study of PD-related depression, we reviewed the establishment and evaluation strategies of the current animal models of PD-related depression based on both the existing literature and our own research experience, and discussed the possible mechanism and interventions, in order to provide a reference for future research in this area. [ABSTRACT FROM AUTHOR]

Glucose can serve as both the source of energy and regulatory signaling molecule in plant. Due to the environmental and metabolic change, sugar levels could affect various developmental processes. High glucose environment is hardly conductive to the plant growth but cause development arrest. Increasing evidence indicate that alternative splicing (AS) plays a pivotal role in sugar signaling. However, the regulatory mechanism upon glucose stress remains unclear. The full-length transcriptomes were obtained from the samples of Arabidopsis seedlings with 3% glucose and mock treatment, using Oxford Nanopore sequencing technologies. Further analysis indicated that many genes involved in photosynthesis were significantly repressed and many genes involved in glycolysis, mitochondrial function, and the response to oxidative stress were activated. In total, 1,220 significantly differential alternative splicing (DAS) events related to 619 genes were identified, among which 75.74% belong to intron retention (IR). Notably, more than 20% of DAS events come from a large set of glycine-rich protein (GRP) family genes, such as GRP7 , whose AS types mostly belong to IR. Besides the known productive GRP transcript isoforms, we identified a lot of splicing variants with diverse introns spliced in messenger RNA (mRNA) region coding the glycine-rich (GR) domain. The AS pattern of GRP s changed and particularly, the productive GRP s increased upon glucose stress. These ASs of GRP pre-mRNAs triggered by glucose stress could be abolished by AZD-8055, which is an ATP competitive inhibitor for the target of rapamycin (TOR) kinase but could be mimicked by H2O2. Additionally, AS pattern change of arginine/serine-rich splicing factor 31 (RS31) via TOR pathway, which was previously described in response to light and sucrose signaling, was also induced in a similar manner by both glucose stress and reactive oxygen species (ROS). Here we conclude that (i) glucose stress suppresses photosynthesis and activates the glycolysis-mitochondria energy relay and ROS scavenging system; (ii) glucose stress triggers transcriptome-wide AS pattern changes including a large set of splicing factors, such as GRP s and RS31 ; (iii) high sugars regulate AS pattern change of both GRP s and RS31 via TOR-ROS pathway. The results from this study will deepen our understanding of the AS regulation mechanism in sugar signaling. [ABSTRACT FROM AUTHOR]

Sugars are involved in plant growth, fruit quality, and signaling perception. Therefore, understanding the mechanisms involved in soluble sugar accumulation is essential to understand fruit development. Here, we report that MdPFPβ, a pyrophosphate‐dependent phosphofructokinase gene, regulates soluble sugar accumulation by enhancing the photosynthetic performance and sugar‐metabolizing enzyme activities in apple (Malus domestica Borkh.). Biochemical analysis revealed that a basic helix‐loop‐helix (bHLH) transcription factor, MdbHLH3, binds to the MdPFPβ promoter and activates its expression, thus promoting soluble sugar accumulation in apple fruit. In addition, MdPFPβ overexpression in tomato influenced photosynthesis and carbon metabolism in the plant. Furthermore, we determined that MdbHLH3 increases photosynthetic rates and soluble sugar accumulation in apple by activating MdPFPβ expression. Our results thus shed light on the mechanism of soluble sugar accumulation in apple leaves and fruit: MdbHLH3 regulates soluble sugar accumulation by activating MdPFPβ gene expression and coordinating carbohydrate allocation. [ABSTRACT FROM AUTHOR]

Background: Mechanical thrombectomy (MT) is an effective treatment for large-vessel occlusion in acute ischemic stroke, however, only some revascularized patients have a good prognosis. For stroke patients undergoing MT, predicting the risk of unfavorable outcomes and adjusting the treatment strategies accordingly can greatly improve prognosis. Therefore, we aimed to develop and validate a nomogram that can predict 3-month unfavorable outcomes for individual stroke patient treated with MT.Methods: We analyzed 258 patients with acute ischemic stroke who underwent MT from January 2018 to February 2021. The primary outcome was a 3-month unfavorable outcome, assessed using the modified Rankin Scale (mRS), 3-6. A nomogram was generated based on a multivariable logistic model. We used the area under the receiver-operating characteristic curve to evaluate the discriminative performance and used the calibration curve and Spiegelhalter's Z-test to assess the calibration performance of the risk prediction model.Results: In our visual nomogram, gender (odds ratio [OR], 3.40; 95%CI, 1.54-7.54), collateral circulation (OR, 0.46; 95%CI, 0.28-0.76), postoperative mTICI (OR, 0.06; 95%CI, 0.01-0.50), stroke-associated pneumonia (OR, 5.76; 95%CI, 2.79-11.87), preoperative Na (OR, 0.82; 95%CI, 0.72-0.92) and creatinine (OR, 1.02; 95%CI, 1.01-1.03) remained independent predictors of 3-month unfavorable outcomes in stroke patients treated with MT. The area under the nomogram curve was 0.8791 with good calibration performance (P = 0.873 for the Spiegelhalter's Z-test).Conclusions: A novel nomogram consisting of gender, collateral circulation, postoperative mTICI, stroke-associated pneumonia, preoperative Na and creatinine can predict the 3-month unfavorable outcomes in stroke patients treated with MT. [ABSTRACT FROM AUTHOR]

Background: Little is known about the role of dietary diversity changes in affecting cognitive function among older people. Therefore, we aimed to evaluate the associations between dietary diversity scores (DDS) changes with cognitive impairment among older adults in a large prospective cohort. Methods: Cognitive function was assessed using the Mini-Mental State Examination questionnaire at baseline and follow-up. A total of 9726 participants without Parkinson's disease, dementia, or cognitive impairment were enrolled at baseline. Nine food groups were collected using simplified FFQ at baseline and follow-up surveys. Then nine food groups change patterns and DDS change patterns (overall, plant-based and animal-based) were assessed. The associations of above DDS changes patterns with subsequent cognitive impairment were evaluated. A multivariable-adjusted Cox proportional hazards model was used to estimate HRs and 95%CIs. Results: We documented 2805 cognitive impairments during 52,325 person-years of follow-up. Compared to high-to-high overall DDS change patterns, the multivariable adjusted HRs (95%CI) for high-to-medium, medium-to-medium, medium-to-low, low-to-medium and low-to-low DDS change patterns were 1.33 (1.12–1.57), 1.11 (0.94–1.32), 1.61 (1.39–1.86), 2.00 (1.66–2.40), 2.30 (1.90–2.78) and 2.80 (2.23–3.53), respectively. Compared with participants with stable DDS change pattern, those who in large improvement of DDS had a 13% lower risk of cognitive impairment (HRs, 0.87; 95%CI: 0.78–0.98). The associations of plant-based DDS, animal-based DDS, or nine food groups DDS change patterns with cognitive impairment were in a similar direction to the main result. Conclusions: Protective associations between maintaining high DDS and a reduced risk of cognitive impairment were observed. In contrast, lowering or maintaining a lower DDS increases the risk of cognitive impairment. [ABSTRACT FROM AUTHOR]

Tumour-associated macrophages (TAMs) represent an attractive cell target for anticancer therapy. However, selective and efficient targeting of TAMs remains difficult. Here, we constructed a novel dually functionalised nanoparticle platform (s-Tpep-NPs) by surface co-modification of nanoparticles (NPs) with tuftsin (Tpep) and legumain protease-sheddable polyethylene glycol 5k (PEG5k) to achieve selective targeted delivery to TAMs. The fluorescence resonance energy transfer experiment and in vitro cellular uptake assay confirmed that s-Tpep-NPs can responsively shed PEG5k and transform into active Tpep-NPs upon the cleavage of legumain that is overexpressed on TAM surfaces, which then promotes TAM phagocytosis through Fc receptor-mediated pathways. Owing to the shielding effect by legumain-sheddable PEG5k, s-Tpep-NPs can effectively decrease the Tpep-induced non-specific accumulation in mononuclear phagocyte system (MPS) organs during systemic circulation. Moreover, s-Tpep-NPs can significantly enhance the tumoural accumulation and improve the specificity and efficiency of targeting to TAMs, as compared with both controls of Tpep-NPs and non-sheddable ns-Tpep-NPs. Overall, this study provides a robust nanoplatform with a novel avenue for improved selectivity of targeted delivery to TAMs. [ABSTRACT FROM AUTHOR]

In this study, we screened bacterial strains to identify specific probiotics to treat pig diarrhea caused by Escherichia coli or Salmonella. The potential probiotics were assayed for their survival in gastrointestinal solution, their antimicrobial activity, cell-surface properties, adhesion to Caco-2 cells, and inhibition of pathogen adhesion. Nine out of the 20 strains tested showed high tolerance of a simulated gastrointestinal environment and six strains exerted antagonistic effects against enterohemorrhagic E. coli (EHEC) O157:H7 and Salmonella Typhimurium MQ. Lactobacillus johnsonii pDX1e exhibited a higher potent antibacterial activity. Four strains (pDX1a, pDX1e, pDX3a, and pDX5a) displayed auto-aggregation, hydrophobicity, and adhesion to Caco-2 cells similar to those of the reference strain Lacticaseibacillus rhamnosus GG (LGG). Enterococcus durans pDX5a showed the highest adhesion capacity (13.86%), followed by the reference strain LGG (11.20%). All the tested strains competitively suppressed the attachment of pathogens to Caco-2 cells (by 30.73–55.18%); L. johnsonii pDX1e and Ent. durans pDX5a significantly inhibited the adhesion of pathogens by substitution and exclusion, respectively. Therefore, pDX1e and pDX5a were selected as probiotic strains for further investigation and application. [ABSTRACT FROM AUTHOR]

Cops and robber game is a graph searching problem. The goal is to determine the minimum cop number needed to capture the robber. The robber is invisible in the zero-visibility cops and robber searching model: the cops have no information about the location of the robber at any time. This problem can be abstracted into a vertex cleaning model. By studying the properties of the three-dimensional grid, the vertex set of the three-dimensional grid can be divided into two subsets, and the relationship between the smaller subset and the boundary is deduced. Then, the results in the partition can be applied to prove the lower bound of the minimum cop number, and a monotonic search strategy is constructed to determine the upper bound. Finally, a zero-visibility cops and robber game algorithm on the three-dimensional grid is proposed. [ABSTRACT FROM AUTHOR]

Background: MADS-box transcription factors (TFs) are the key regulators of multiple developmental processes in plants; among them, a chrysanthemum MADS-box TF CmANR1 has been isolated and described as functioning in root development in response to high nitrate concentration signals. However, how CmANR1 affects root and shoot development remains unclear. Results: We report that CmANR1 plays a positive role in root system development in chrysanthemum throughout the developmental stages of in vitro tissue cultures. Metabolomics combined with transcriptomics assays show that CmANR1 promotes robust root system development by facilitating nitrate assimilation, and influencing the metabolic pathways of amino acid, glycolysis, and the tricarboxylic acid cycle (TCA) cycle. Also, we found that the expression levels of TFs associated with the nitrate signaling pathways, such as AGL8, AGL21, and LBD29, are significantly up-regulated in CmANR1-transgenic plants relative to the wild-type (WT) control; by contrast, the expression levels of RHD3-LIKE, LBD37, and GATA23 were significantly down-regulated. These results suggest that these nitrate signaling associated TFs are involved in CmANR1-modulated control of root development. In addition, CmANR1 also acts as a positive regulator to control shoot growth and development. Conclusions: These findings provide potential mechanisms of MADS-box TF CmANR1 modulation of root and shoot development, which occurs by regulating a series of nitrate signaling associated TFs, and influencing the metabolic pathways of amino acid and glycolysis, as well as TCA cycle and nitrate assimilation. [ABSTRACT FROM AUTHOR]

Summary: Changes in carbohydrates and organic acids largely determine the palatability of edible tissues of horticulture crops. Elucidating the potential molecular mechanisms involved in the change in carbohydrates and organic acids, and their temporal and spatial crosstalk are key steps in understanding fruit developmental processes. Here, we used apple (Malus domestica Borkh.) as research materials and found that MdbHLH3, a basic helix–loop–helix transcription factor (bHLH TF), modulates the accumulation of malate and carbohydrates. Biochemical analyses demonstrated that MdbHLH3 directly binds to the promoter of MdcyMDH that encodes an apple cytosolic NAD‐dependent malate dehydrogenase, activating its transcriptional expression, thereby promoting malate accumulation in apple fruits. Additionally, MdbHLH3 overexpression increased the photosynthetic capacity and carbohydrate levels in apple leaves and also enhanced the carbohydrate accumulation in fruits by adjusting carbohydrate allocation from sources to sinks. Overall, our findings provide new insights into the mechanism of how the bHLH TF MdbHLH3 modulates the fruit quality. It directly regulates the expression of cytosolic malate dehydrogenase MdcyMDH to coordinate carbohydrate allocation and malate accumulation in apple. [ABSTRACT FROM AUTHOR]

Background and Objectives: Methyl 3,4-dihydroxybenzoate (MDHB) has the potential to prevent neurodegenerative diseases (NDDs). The present work investigated its excretion, metabolism, and cytochrome P450-based drug–drug interactions (DDIs). Methods: After intragastric administration of MDHB, the parent drug was assayed in the urine and faeces of mice. Metabolites of MDHB in the urine, faeces, brain, plasma and liver were detected by liquid chromatography–hybrid quadrupole time-of-flight mass spectrometry (LC–QTOF/MS). A cocktail approach was used to evaluate the inhibition of cytochrome P450 isoforms by MDHB. Results: The cumulative excretion permille of MDHB in the urine and faeces were found to be 0.67 ± 0.31 and 0.49 ± 0.44‰, respectively. A total of 96 metabolites of MDHB were identified, and all IC50 (half-maximal inhibitory concentration) values of MDHB towards cytochrome P450 isoforms were > 100 μM. Conclusions: The results suggest that MDHB has a low parent drug cumulative excretion percentage and that MDHB has multiple metabolites and is mainly metabolized through the loss of –CH2 and –CO2, the loss of –CH2O, ester bond hydrolysis, the loss of –O and –CO2, isomerization, methylation, sulfate conjugation, the loss of –CH2O and –O and glycine conjugation, glycine conjugation, the loss of two –O groups and alanine conjugation, the loss of –CH2O and –O and glucose conjugation, glucuronidation, glucose conjugation, etc., in vivo. Finally, MDHB has a low probability of cytochrome P450-based DDIs. [ABSTRACT FROM AUTHOR]

Background and Objectives: Methyl 3,4-dihydroxybenzoate (MDHB) has the potential to prevent neurodegenerative diseases (NDDs). The present work aims to reveal the pharmacokinetics and tissue distribution characteristics of MDHB.Methods: The pharmacokinetics and tissue distribution of MDHB were analyzed using LC-MS/MS after a single intragastric administration (50 to 450 mg/kg) in mice, and samples were collected from five animals at specific time points.Results: Pharmacokinetic parameters of MDHB following intragastric administrations were: the time to peak concentration (Tmax) ranged from 0.033 to 0.07 h, the peak concentration (Cmax) ranged from 12,379.158 to 109798.712 μg/l, the elimination half-life (t1/2z) ranged from 0.153 to 1.291 h, the area under the curve (AUC0-∞) ranged from 640.654 to 20,241.081 μg/l × h, the mean residence time (MRT0-∞) ranged from 0.071 to 0.206 h, the apparent volume of distribution (Vz/F) ranged from 17.538 to 45.244 l/kg, and the systemic clearance (Clz/F) ranged from 22.541 to 80.807 l/h/kg. The oral bioavailability of MDHB was 23%. The maximum MDHB content was detected in the stomach, and the minimum content was observed in the testes; the peak content in the brain was 15,666.93 ng/g.Conclusions: The pharmacokinetic characteristics of MDHB include fast absorption, high systemic clearance, a short half-life and an oral bioavailability of 23%. Additionally, MDHB permeates the blood-brain barrier (BBB) and is rapidly distributed to all organs. The identification of the pharmacokinetics of MDHB following its oral administration will contribute to further preclinical and clinical studies of its effects. [ABSTRACT FROM AUTHOR]

The insulin superfamily is a group of homologous proteins that are further divided into the insulin family and relaxin family according to their distinct receptors. All insulin superfamily members contain three absolutely conserved disulfide linkages and a nonchiral Gly residue immediately following the first B-chain cysteine. The functionality of this conserved Gly residue in the insulin family has been studied by replacing it with natural l-amino acids or the corresponding unnatural d-amino acids. However, such analysis has not been conducted on relaxin family members. In the present study, we conducted chiral mutagenesis on the conserved B11Gly of the chimeric relaxin family peptide R3/I5, which is an efficient agonist for receptor RXFP3 and RXFP4. Similar to the effects on insulin family foldability, l-Ala or l-Ser substitution completely abolished the in vitro refolding of a recombinant R3/I5 precursor; whereas, d-Ala or d-Ser substitution had no detrimental effect on refolding of a semi-synthetic R3/I5 precursor, suggesting that the conserved Gly residue controls the foldability of relaxin family members. In contrast to the effect on insulin family activity, d-Ala or d-Ser replacement had no detrimental effect on the binding and activation potencies of the mature R3/I5 towards both RXFP3 and RXFP4, suggesting that the conserved Gly residue is irrelevant to the relaxin family's activity. The present study revealed functionality of the conserved B-chain Gly residue for a relaxin family peptide for the first time, providing an overview of its contribution to foldability and activity of the insulin superfamily. [ABSTRACT FROM AUTHOR]

Liver‐expressed antimicrobial peptide 2 (LEAP2) is a highly conserved secretory peptide first isolated in 2003. However, its exact biological functions remained elusive until a recent study identified it as an endogenous antagonist for the growth hormone secretagogue receptor (GHSR1a), a G protein‐coupled receptor for which the gastric peptide ghrelin is the endogenous agonist. By tuning the ghrelin–GHSR1a system, LEAP2 has an important function in energy metabolism. In the present study, we first demonstrated that LEAP2 and ghrelin actually bound to GHSR1a in a competitive manner, rather than in a non‐competitive manner as previously reported, by binding assays and activation assays. Subsequently, we demonstrated that the antagonistic function of LEAP2 was drastically affected by the manner of its addition. LEAP2 primarily affected the maximal activation effect when added before ghrelin, whereas it primarily affected half‐maximal effective concentration when added at the same time as ghrelin. Thus, LEAP2 behaved as a competitive antagonist if added at the same time as the agonist and a non‐competitive antagonist if added before the agonist. This unusual property of LEAP2 might be caused by its slow dissociation from receptor GHSR1a. We also found that the N‐terminal fragment of LEAP2 was important for receptor binding. Our present study revealed an antagonistic mechanism for LEAP2, and will facilitate the design of novel antagonists for receptor GHSR1a in future studies. Using binding assays, we demonstrated liver‐expressed antimicrobial peptide 2 (LEAP2) was a competitive antagonist for ghrelin receptor GHSR1a. However, the manner of addition affected LEAP2's function in activation assays: it behaved as a competitive antagonist when added at the same time as ghrelin, whereas it behaved as a non‐competitive antagonist when added before ghrelin. Its slow dissociation from GHSR1a might cause this unusual property. This study provides new insights into LEAP2's tuning of the ghrelin–GHSR1a system. [ABSTRACT FROM AUTHOR]

Summary: The plant hormone ethylene is critical for climacteric fruit ripening, while glucose and anthocyanins determine the fruit quality of climacteric fruits such as apple. Understanding the exact molecular mechanism for this process is important for elucidating the interconnection of ethylene and fruit quality.Overexpression of apple MdbHLH3 gene, an anthocyanin‐related basic helix–loop–helix transcription factor (bHLH TF) gene, promotes ethylene production, and transgenic apple plantlets and trees exhibit ethylene‐related root developmental abnormalities, premature leaf senescence, and fruit ripening. Biochemical analyses demonstrate that MdbHLH3 binds to the promoters of three genes that are involved in ethylene biosynthesis, including MdACO1, MdACS1, and MdACS5A, activating their transcriptional expression, thereby promoting ethylene biosynthesis.High glucose‐inhibited U‐box‐type E3 ubiquitin ligase MdPUB29, the ortholog of Arabidopsis AtPUB29 in apple, influences the expression of ethylene biosynthetic genes and ethylene production by direct ubiquitination of the MdbHLH3 protein.Our findings provide new insights into the ubiquitination of MdbHLH3 by glucose‐inhibited ubiquitin E3 ligase MdPUB29 in the regulation of ethylene biosynthesis as well as indicate that the regulatory module MdPUB29‐MdbHLH3 connects ethylene biosynthesis with fruit quality in apple. [ABSTRACT FROM AUTHOR]

Relaxin family peptides perform a variety of biological functions by binding and activating relaxin family peptide receptor 1-4 (RXFP1-4), four A-class G protein-coupled receptors. In the present work, we developed a novel ligand binding assay for RXFP3 and RXFP4 based on NanoLuc complementation technology (NanoBiT). A synthetic ligation version of the low-affinity small complementation tag (SmBiT) was efficiently ligated to the A-chain N terminus of recombinant chimeric agonist R3/I5 using recombinant circular sortase A. After the ligation product R3/I5-SmBiT was mixed with human RXFP3 or RXFP4 genetically fused with a secretory large NanoLuc fragment (sLgBiT) at the N terminus, NanoLuc complementation was induced by high-affinity ligand-receptor binding. Binding kinetics and affinities of R3/I5-SmBiT with sLgBiT-fused RXFP3 and RXFP4 were conveniently measured according to the complementation-induced bioluminescence. Using R3/I5-SmBiT and the sLgBiT-fused receptor as a complementation pair, binding potencies of various ligands with RXFP3 and RXFP4 were quantitatively measured without the cumbersome washing step. The novel NanoBiT-based ligand binding assay is convenient for use and suitable for automation, thus will facilitate interaction studies of RXFP3 and RXFP4 with ligands in future. This assay can also be applied to some other plasma membrane receptors for pharmacological characterization of ligands in future studies. [ABSTRACT FROM AUTHOR]

Summary: This study was performed to evaluate the effect of partial gelatinisation on the retrogradation of modified potato starch. The partially gelatinised starches with gelatinisation degree at mean levels of 22.47%, 49.18%, 76.80% and 86.19% were prepared by ball milling (0.5, 1.5, 3 and 10 h). The thermal properties and crystal structure of retrograded starch were examined during 21 days of refrigerated storage at 4 °C. Retrograded starch with high initial gelatinisation degree (86.19%) showed higher retrogradation enthalpy of 6.12 ± 0.18 J g−1 and lower onset temperature of 45.41 ± 0.24 °C than sample with low gelatinisation degree (22.47%) where the results were 1.32 ± 0.18 J g−1 and 54.05 ± 0.03 °C, respectively. During storage, two peaks in the X‐ray diffractograms for starch with high gelatinisation degree appeared and increased rapidly, while the peaks for starch with low gelatinisation degree increased slowly. These results suggest that a certain amount of remainder crystals presented in partially gelatinised starch impeded the retrogradation. [ABSTRACT FROM AUTHOR]

Background: The roles in photosystem I (PSI) assembly of the nucleus-encoded thylakoid protein Y3IP1 who interacts with the plastid-encoded Ycf3 protein that has been well-characterized in plants. However, its function and potential mechanisms in other aspects remain poorly understood. Results: We identified the apple MdY3IP1 gene, which encodes a protein highly homologous to the Arabidopsis Y3IP1 (AtY3IP1). Ectopic expression of MdY3IP1 triggered early-flowering and enhanced salt tolerance in Arabidopsis plants. MdY3IP1 controlled floral transition by accelerating sugar metabolism process in plant cells, thereby influencing the expression of flowering-associated genes. The increase in salt stress tolerance in MdY3IP1-expressing plants correlated with reduced reactive oxygen species (ROS) accumulation, and an increase in lateral root development by regulating both auxin biosynthesis and transport, as followed by enhancement of salt tolerance in Arabidopsis. Overall, these findings provide new evidences for additional functions of Y3IP1-like proteins and their underlying mechanisms of which Y3IP1 confers early-flowering and salt tolerance phenotypes in plants. Conclusions: These observations suggest that plant growth and stress resistance can be affected by the regulation of the MdY3IP1 gene. Further molecular and genetic approaches will accelerate our knowledge of MdY3IP1 functions in PSI complex formation and plants stress resistance, and inform strategies for creating transgenic crop varieties with early maturity and high-resistant to adverse environmental conditions. [ABSTRACT FROM AUTHOR]

Relaxin family is a group of peptide hormones with a variety of biological functions by activating G protein-coupled receptors RXFP1-4. We recently developed bioluminescent tracers for their receptor-binding assays by chemical conjugation with the ultrasensitive NanoLuc reporter. To simplify preparation of the bioluminescent tracers, in the present study, we established a sortase-catalysed ligation approach using the chimeric R3/I5 as a model. Following catalysis by recombinant sortase A, a NanoLuc reporter carrying the LPETG sortase recognition motif at the C-terminus was efficiently ligated to an R3/I5 peptide carrying four successive Gly residues at the A-chain N-terminus, via the formation of a peptide bond between the C-terminal LPET sequence of NanoLuc and the A-chain N-terminal Gly residue of R3/I5. Saturation binding assays demonstrated that the NanoLuc-ligated R3/I5 retained high binding affinity to RXFP3 and RXFP4, with the calculated dissociation constants ( K ) of 4.34 ± 0.33 nM ( n = 3) and 5.66 ± 0.54 nM ( n = 3), respectively. Using the NanoLuc-ligated R3/I5 as a tracer in competition binding assays, binding potencies of various ligands towards RXFP3 and RXFP4 were conveniently quantified. This work provides a simple method for rapid preparation of bioluminescent tracers for relaxin family peptides and other protein/peptide hormones for ligand-receptor interaction studies. [ABSTRACT FROM AUTHOR]

Relaxin family peptide receptor 3 (RXFP3) is an A-class G protein-coupled receptor that is implicated in the regulation of food intake and stress response upon activation by its cognate agonist relaxin-3. To study its interaction with various ligands, we developed a novel bioluminescence resonance energy transfer (BRET)-based binding assay using the brightest NanoLuc as an energy donor and a newly developed cyan-excitable orange fluorescent protein (CyOFP) as an energy acceptor. An engineered CyOFP without intrinsic cysteine residues but with an introduced cysteine at the C-terminus was overexpressed in Escherichia coli and chemically conjugated to the A-chain N-terminus of an easily labeled chimeric R3/I5 peptide via an intermolecular disulfide linkage. After the CyOFP-conjugated R3/I5 bound to a shortened human RXFP3 (removal of 33 N-terminal residues) fused with the NanoLuc reporter at the N-terminus, high BRET signals were detected. Saturation binding and real-time binding assays demonstrated that this BRET pair retained high binding affinity with fast association/dissociation. Using this BRET pair, binding potencies of various ligands with RXFP3 were conveniently measured through competition binding assays. Thus, the novel BRET-based binding assay facilitates interaction studies of RXFP3 with various ligands. The engineered CyOFP without intrinsic cysteine residues may also be applied to other BRET-based binding assays in future studies. [ABSTRACT FROM AUTHOR]

Relaxin-3 is an insulin/relaxin superfamily neuropeptide implicated in the regulation of food intake and stress response via activation of the G protein-coupled receptor RXFP3. Their electrostatic interactions have been recently identified, and involves three positively charged B-chain residues (B12Arg, B16Arg, and B26Arg) of relaxin-3 and two negatively charged residues (Glu141 and Asp145) in a highly conserved ExxxD motif at the extracellular end of the second transmembrane domain of RXFP3. To investigate their hydrophobic interactions, in the present work we deleted the highly conserved B-chain C-terminal B27Trp residue of relaxin-3, and mutated four highly conserved aromatic residues (Phe137, Trp138, Phe146, and Trp148) around the ExxxD motif of RXFP3. The resultant [∆B27W]relaxin-3 exhibited approximately tenfold lower binding potency and ~1000-fold lower activation potency towards wild-type RXFP3, confirming its importance for relaxin-3 function. Although the RXFP3 mutants could be normally trafficked to cell membrane, they had quite different activities. [F137A]RXFP3 could normally distinguish wild-type relaxin-3 and [∆B27W]relaxin-3 in binding and activation assays, whereas [W138A]RXFP3 lost most of this capability, suggesting that the Trp138 residue of RXFP3 forms hydrophobic interactions with the B27Trp residue of relaxin-3. The hydrophobic Trp138 residue and the formerly identified negatively charged Glu141 and Asp145 residues in the highly conserved WxxExxxD motif may thus form a functional surface that is important for interaction with relaxin-3. We hypothesize that the relaxin-3 B-chain C-terminus changes from the original folding-back conformation to an extended conformation during binding with RXFP3, to allow its B27Trp and B26Arg residues to interact with the Trp138 and Glu141 residues of RXFP3, respectively. [ABSTRACT FROM AUTHOR]

This study investigated the neuroprotective effects of methyl 3,4-dihydroxybenzoate (MDHB) against t-butyl hydroperoxide (TBHP) induced oxidative damage in SH-SY5Y (human neuroblastoma cells) and the underlying mechanisms. SH-SY5Y were cultured in DMEM + 10% FBS for 24 h and pretreated with different concentrations of MDHB or N-acetyl-l-cysteine (NAC) for 4 h prior to the addition of 40 μM TBHP for 24 h. Cell viability was analyzed using the methylthiazolyltetrazolium (MTT) and lactate dehydrogenase (LDH) assays. An annexin V-FITC assay was used to detect cell apoptosis rates. The 2′,7′-dichlorofluorescin diacetate (DCFH-DA) assay was used to determine intracellular ROS levels. The activities of antioxidative enzymes (GSH-Px and SOD) were measured using commercially available kits. The oxidative DNA damage marker 8-OHdG was detected using ELISA. Western blotting was used to determine the expression of Bcl-2, Bax, caspase 3, p-Akt and Akt proteins in treated SH-SY5Y cells. Our results showed that MDHB is an effective neuroprotective compound that can mitigate oxidative stress and inhibit apoptosis in SH-SY5Y cells. [ABSTRACT FROM AUTHOR]

Relaxin is a prototype of the relaxin family peptide hormones and plays important biological functions by binding and activating the G protein-coupled receptor RXFP1. To study their interactions, in the present work, we applied the newly developed bioluminescent ligand-receptor binding assay to the relaxin-RXFP1 system. First, a fully active easily labeled relaxin, in which three Lys residues of human relaxin-2 were replaced by Arg, was prepared through overexpression of a single-chain precursor in Pichia pastoris and in vitro enzymatic maturation. Thereafter, the B-chain N-terminus of the easily labeled relaxin was chemically cross-linked with a C-terminal cysteine residue of an engineered NanoLuc through a disulfide linkage. Receptor-binding assays demonstrated that the NanoLuc-conjugated relaxin retained high binding affinity with the receptor RXFP1 ( K = 1.11 ± 0.08 nM, n = 3) and was able to sensitively monitor binding of a variety of ligands with RXFP1. Using the novel bioluminescent binding assay, we demonstrated that three highly conserved B-chain Arg residues of relaxin-3 had distinct contributions to binding of the receptor RXFP1. In summary, our present work provides a novel bioluminescent ligand-receptor binding assay for the relaxin-RXFP1 system to facilitate their interaction studies, such as characterization of relaxin analogues or screening novel agonists or antagonists of RXFP1. [ABSTRACT FROM AUTHOR]

The effect of annealing on the microstructural evolution and mechanical properties of high-density polyethylene parts molded via gas-assisted injection molding was investigated using scanning electron microscopy, differential scanning calorimetry, two-dimensional wide-angle X-ray diffraction and tensile testing. The results indicated that a variety of annealing temperatures could induce considerable variations in the hierarchical structures, crystallinity, lamellar thickness and yield stress of the molded bars. According to these results, the annealing temperatures could be divided into three regions. In the low-temperature region of annealing at 80 °C, the spatial variation of the superstructure developed along the thickness direction and mechanical properties of the annealed sample were mainly unchanged and similar to those of the original specimen. At 100 and 120 °C, the intermediate temperature region of annealing, the thickness of the crystals, degree of orientation and yield stress of annealed samples were greatly improved. Finally, at 127 °C, the degree of orientation decreased and yield stress slightly improved, an indication of the high-temperature annealing region being characterized by increasing melting/recrystallization and causing relaxation of oriented molecular chains. A model is proposed to interpret the mechanism of the annealing treatment of the samples at various temperatures. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The hierarchy structures and orientation behavior of high-density polyethylene (HDPE) molded by conventional injection molding (CIM) and gas-assisted injection molding (GAIM) were intensively examined by using scanning electronic microscopy (SEM) and 2D wide-angle X-ray diffraction (2D-WAXD). Results show that the spatial variation of crystals across the thickness of sample molded by CIM was characterized by a typical skin-core structure as a result of general shear-induced crystallization. Unusually, the crystalline morphologies of the parts prepared by GAIM, primarily due to the penetration of secondary high-compressed gas that was exerted on the polymer melt during gas injection, featured a richer and fascinating supermolecular structure. Besides, the oriented lamellar structure, general shish-kebab structure, and common spherulites existed in the skin, sub-skin, and gas channel region, respectively; a novel morphology of shish-kebab structure was seen in the sub-skin layer of the GAIM parts of HDPE. This special shish-kebab structure (recognized as 'bending shish-kebab') was neither parallel nor perpendicular to the flow direction but at an angle. Furthermore, there was a clear interface between the bending and the normal shish-kebab structures, which may be very significant for our understanding of the melt flow or polymer rheology under the coupling effect of multi-fluid flow and complex temperature profiles in the GAIM process. Based on experimental observations, a schematic illustration was proposed to interpret the formation mechanism of the bending shish-kebab structure during GAIM process. [ABSTRACT FROM AUTHOR]

We demonstrated the geometrical effect of nano zinc-oxide (ZnO) on the electro-optical response of a nematic liquid crystal (LC). The experimental results indicated that anisotropic geometrical (nano-rod) ZnO will markedly enhance the photo-refractive effects of host LC, whereas isotropic geometrical (nano-particle) ZnO possess no such effects at all. With the help of photoluminescence spectra and photo-current measurement, we further prove that the geometries of dopants play decisive roles in determining the yield of photo-electron. These results are useful to the nano-technology application of nano-ZnO. [ABSTRACT FROM AUTHOR]

The design of a low-power high-speed output buffer amplifier for driving the large column line loads of large-size TFT-LCDs is presented. The major circuit of the output buffer is a rail-to-rail current mirror amplifier which can control the class-AB output stage and auxiliary output stage at the same time; the proposed output buffer thus has a push-pull dual-path function for high-speed operation. Since a conventional class-AB output stage requires two bias voltages, the proposed output buffer provides two dynamic bias voltages to increase the transient response of the class-AB output stage. The two dynamic biases use only two transistors and do not increase the quiescent current. The proposed output buffer is implemented on standard 0.35 μm CMOS 2-poly 4-metal process technology and simulated using HSPICE. The power consumption is 23.1 μW, with settling times of 0.7 and 0.68 μs for rising and falling edges, respectively, under a 1000 pF load. The active area of the output buffer amplifier is only 48 × 48 μm. [ABSTRACT FROM AUTHOR]

A low-dropout (LDO) regulator with tail current control (TCC) is presented. The TCC consists of a dual differential pair, a 5-bit current digital-to-analog converter, and a current summation circuit. The TCC adjusts the tail current ratio of the dual differential pair of the LDO regulator to achieve a programmable output voltage using 5-bit digital signals. A supply-ripple isolation mechanism is added to improve the power supply rejection over a wide frequency range. The proposed design is fabricated in the TSMC 0.18-\mu \m 1-poly 6-metal complementary metal–oxide–semiconductor process. Experimental results show that the LDO regulator has a 32-level programmable output voltage ranging from 1 to 1.2 V, making the LDO regulator suitable for correcting the oscillator frequency of a digital pulsewidth modulator. [ABSTRACT FROM PUBLISHER]

A 640-channel 6-bit LCD column driver with a cross-self-bias push–pull buffer is presented. To design a column driver for thin-film transistor liquid-crystal displays (TFT-LCDs), both low power consumption and chip area are key problems that must be solved. Therefore, the proposed cross-self-bias buffer amplifier effectively reduces the circuit area and power consumption overheads of conventional class-AB biasing techniques. The 640-channel 6-bit column driver is implemented using 0.18-\mu\m high-voltage CMOS technology. The proposed column driver is then used in an SXGA LCD panel to perform the experimental characterization. The measured performance of column driver exhibits maximum settling times of 1.4 \mu \s and 1.2 \mu \s for rising and falling edges, respectively, under one-dot inversion. The quiescent current consumption of the proposed rail-to-rail buffer is about 4 \mu \A. [ABSTRACT FROM PUBLISHER]