Analysis of H5N8 influenza virus infection in chicken with mApple reporter genes in vivo and in vitro.

H5N8 highly pathogenic avian influenza virus (HPAIV) has caused huge losses to the global poultry industry and critically threatens public health. Chickens are the important host for the transmission. However, the distribution of H5N8 avian influenza virus (AIV) in chicken and the infected cell types are limitedly studied. Therefore, in this study, we detected viral replication and infection by generating recombinant H5N8 AIV expressing an easily tracked mApple fluorescent reporter. The results showed that recombinant viruses passaged four times in chicken embryos successfully expressed mApple proteins detected by fluorescence microscopy and WB, which verified that the constructed recombinant viruses were stable. Compared to parental virus, although recombinant virus attenuated for replication in MDCK cells, it can still replicate effectively, and form visible plaques. Importantly, the experiments on infection of chicken PBMCs in vitro showed a strong correlation between mApple positivity rate and NP positivity rate (r = 0.7594, P =0.0176), demonstrating that mApple reporter could be used as an indicator to accurately reflect AIV infection. Then we infected monocytes/macrophages in PBMCs in vitro and detected the mApple positive percentage was 55.1%-80.4%, which confirmed the chicken primary monocytic/macrophages are important target cells for avian influenza virus infection. In chicken, compared with parental virus, the recombinant virus-infected chickens had lower viral titers in oropharyngeal cloacal and organs, but it can cause significant pathogenicity in chicken and the mortality rate was approximately 66%. In addition, the results of bioluminescent imaging showed that the fluorescence in the lungs was strongest at 5 days post-infection (DPI). Finally, we discovered the mApple positive expression in chicken lung immune cells (CD45+ cells), especially some T cells (CD4 and CD8 T cells) also carrying mApple, which indicates that the H5N8 AIV showed a tropism for immune cells including chicken T cells causing potentially aggressive against cellular immunity. We have provided a simple visualization for further exploration of H5N8 AIV infected chicken immune cells, which contributes to further understanding pathogenic mechanism of H5N8 AIV infection in chicken.

Inhibition of water-diluted precipitate formation from egg whites by ultrasonic pretreatment: Insights from quantitative proteomics analysis.

The formation of the egg white precipitate (EWP) during dilution poses challenges in food processing. In this paper, the effects of 90 W and 360 W ultrasonic intensities on the inhibition of EWP formation were investigated. The findings revealed that 360 W sonication effectively disrupted protein aggregates, decreasing the dry matter of EWP by 5.24 %, particle size by 57.86 %, and viscosity by 82.28 %. Furthermore, the ultrasonic pretreatment unfolded protein structures and increased the content of ß-sheet structures. Combined with quantitative proteomics and intermolecular forces analysis, the mechanism by which ultrasonic pretreatment inhibited water-diluted EWP formation by altering protein interactions was proposed: ultrasonic pretreatment disrupted electrostatic interactions centered on lysozyme, as well as hydrogen-bonding interactions between ovomucin and water. In conclusion, our research provides valuable insights into the application of ultrasonic pretreatment as a means to control and improve the quality of egg white-based products.

Structural Basis of Nucleic Acid Recognition and 6mA Demethylation by Caenorhabditis elegans NMAD-1A.

N6-methyladenine (6mA) of DNA is an emerging epigenetic mark in the genomes of Chlamydomonas, Caenorhabditis elegans, and mammals recently. Levels of 6mA undergo drastic fluctuation and thus affect fertility during meiosis and early embryogenesis. Here, we showed three complex structures of 6mA demethylase C. elegans NMAD-1A, a canonical isoform of NMAD-1 (F09F7.7). Biochemical results revealed that NMAD-1A prefers 6mA Bubble or Bulge DNAs. Structural studies of NMAD-1A revealed an unexpected "stretch-out" conformation of its Flip2 region, a conserved element that is usually bent over the catalytic center to facilitate substrate base flipping in other DNA demethylases. Moreover, the wide channel between the Flip1 and Flip2 of the NMAD-1A explained the observed preference of NMAD-1A for unpairing substrates, of which the flipped 6mA was primed for catalysis. Structural analysis and mutagenesis studies confirmed that key elements such as carboxy-terminal domain (CTD) and hypothetical zinc finger domain (ZFD) critically contributed to structural integrity, catalytic activity, and nucleosome binding. Collectively, our biochemical and structural studies suggest that NMAD-1A prefers to regulate 6mA in the unpairing regions and is thus possibly associated with dynamic chromosome regulation and meiosis regulation.

An Octacarboxylate-Linked Sodium Metal-Organic Framework with High Porosity.

Alkali metal-based metal-organic frameworks (MOFs) with permanent porosity are scarce because of their high tendency to coordinate with solvents such as water. However, these MOFs are lightweight and bear gravimetric benefits for gas adsorption related applications. In this study, we present the successful construction of a microporous MOF, designated as HIAM-111, built solely on sodium ions by using an octacarboxylate linker. The structure of HIAM-111 is based on 8-connected Na4 clusters and exhibits a novel topology with an underlying 32,42,8-c net. Remarkably, HAM-111 possesses a robust and highly porous framework with a BET surface area of 1561 m2/g, significantly surpassing that of the previously reported Na-MOFs. Further investigations demonstrate that HIAM-111 is capable of separating C2H2/CO2 and purifying C2H4 directly from C2H4/C2H2/C2H6 with high adsorption capacities. The current work may shed light on the rational design of robust and porous MOFs based on alkali metals.

The impact of palliative care on the physical and mental status and quality of life of patients with chronic heart failure: A randomized controlled trial.

BACKGROUND: Chronic heart failure (CHF) is the terminal stage of several diseases. The present study aimed to investigate the impact of palliative care on the physical and mental status and quality of life of patients with CHF. METHODS: This single-center randomized controlled clinical trial was conducted at Xiangtan Central Hospital. A total of 103 cases were included and divided into a study group (n = 54) and a control group (n = 49). The control group received usual care, whereas the study group received usual care plus palliative care. Statistical analyses were conducted on Simplified Coping Style Questionnaire, negative emotions, Minnesota Living with Heart Failure Questionnaire scores, and nursing satisfaction before and after intervention in the 2 groups. RESULTS: After the intervention, the positive coping style score in the research group was higher than that in the control group, while the negative coping style score was lower than that of the control group (P < .05). After the intervention, the Beck Anxiety Inventory and Beck Depression Inventory-II scores of the 2 groups decreased compared to before the intervention, and the study group had lower scores than the control group (P < .05). After the intervention, the Minnesota Living with Heart Failure Questionnaire scores of the 2 groups decreased compared to those before the intervention, and the study group had lower scores than the control group (P < .05). Nursing satisfaction of the research group (94.44%) was higher than that of the control group (81.63%) (P < .05). CONCLUSIONS: Adopting palliative care to intervene in CHF patients can effectively regulate their physical and mental state, alleviate negative emotions, transform coping styles towards the disease, and improve their quality of life, with high patient satisfaction.

The clinical value of a nomogram constructed from CEA, CA199, PT, FIB, tumor differentiation and TNM stage in colorectal cancer.

BACKGROUND: The accurate Tumor-Node-Metastasis (TNM) staging of colorectal cancer (CRC) is of great guiding significance for the judgment of tumor progression and prognosis, and the formulation of treatment strategies. OBJECTIVE: The aim of this study was to construct a recurrence risk scoring (RRS) system and prognostic prediction model to improve the accuracy of staging, prognosis prediction, and clinical decision making in resectable CRC. METHODS: CRC patients who underwent radical resection were retrospectively enrolled into study. Multivariable Cox regression model was applied to screen for independent prognostic factors. The RRS system is composed of independent prognostic factors which was awarded 1point each. A prognostic model composed of RRS and TNM staging system (RRS-TNM model) was applied to predict postoperative recurrence. RESULTS: TNM stage, tumor differentiation, preoperative elevated Carcinoembryonic Antigen, Carbohydrate Antigen 199, Prothrombin Time and Fibrinogen were the independent prognostic biomarkers. 173 of 540 patients had recurrence. The 5-year cumulative recurrence rate (5-y CRR) and disease-free survival (DFS) of postoperative p-TNM stage I, II, and III were 12.7% and 104.8 months, 26.5% and 89.3 months, and 55.5% and 57.3 months, respectively. The 5-y CRR and DFS of preoperative Low-risk (RRS 0-1score), Middle-risk (RRS 2-3scores), and High-risk (RRS 4-5scores) groups were 13.9% and 101.1 months, 40.9% and 75.5 months, and 70.2% and 41.1 months. The AUC (area under ROC curve) of RRS system was not inferior to that of TNM staging system (0.713 vs. 0.666; P= 0.093). The AUC (0.770) and C-index value (0.721) of RRS-TNM model were significantly better than both RRS and TNM staging system (P< 0.001). CONCLUSIONS: The RRS system accurately identifies CRC patients with high-risk recurrence preoperatively. Constructing a nomogram using the RRS system and TNM staging significantly improves the accuracy of staging and prognosis prediction, which is of great clinical significance for individualized clinical treatment and follow-up of CRC.

Carpets with visual cues can improve gait in Parkinson's disease patients: may be independent of executive function.

BACKGROUND: Gait impairment is common in Parkinson's disease (PD) patients, which greatly reduces their quality of life. Executive dysfunction is associated with gait impairment. Compensatory strategies, including visual cues, have been shown to be effective in improving PD gait. In this study, we aimed to understand whether carpets with visual cues could improve PD gait, and how the improvement varies across patients with different executive function state. METHODS: We designed carpets with chessboard and stripe cues. A total of 65 Chinese PD patients were recruited. Movement Disorder Society Unified Parkinson's Disease Rating Scale, L-dopa equivalent daily dosage, Hoehn & Yahr stage, Frontal Assessment Battery, Mini Mental State Examination Scale, Hamilton Anxiety Scale, and Hamilton Depression Scale were evaluated. Gait parameters including stride length, gait speed and fall risk were recorded by a wearable electronic device. RESULTS: The stride length and gait speed were significantly improved and the fall risk was significantly mitigated when PD patients walked on carpets with chessboard and stripe patterns. Further analysis showed the amelioration of gait parameters was independent of executive dysfunction. CONCLUSIONS: Our study demonstrates that carpets with visual cues can improve the gait of PD patients even in those with mild executive dysfunction.

Quantitative proteomics provides new insights into the mechanism of improving rehydration of egg white powder by ultrasonic pretreatment.

Poor rehydration is one of the key factors affecting the functional properties of egg white powder (EWP). Reducing rehydrated precipitates is important for the processing and application of EWP. In this study, effects of ultrasonic pretreatment on the physicochemical and functional properties of EWP rehydration solutions were studied with the aim of revealing the mechanism of ultrasonic pretreatment to improve rehydration. Compared with freeze-dried EWP (FD) and spray-dried EWP (SD), the percentage of ultrasonic pretreated FD (UFD) and ultrasonic pretreated SD (USD) rehydrated precipitates decreased by 13.0 % and 5.6 %, respectively, after ultrasonic pretreatment (0.25 W/mL for 10 min); and the average particle sizes of UFD and USD solutions decreased by 22.5 % and 15.5 %, respectively. Fourier transform infrared spectroscopy showed that ultrasonic pretreatment caused higher ß-sheet content in the protein secondary structure of UFD rehydrated precipitates (49.2 %). Quantitative proteomic analysis revealed a decrease in the abundance of major egg white proteins (ovalbumin, ovotransferrin, ovomucoid and ovomucin) in the rehydrated precipitates of UFD, except for lysozyme. It was also shown that lysozyme-centered aggregates were disrupted in the rehydrated precipitates of UFD. Our research suggests that ultrasonic pretreatment improves EWP rehydration by reducing the interactions between high abundance proteins as well as improving the solubility of high abundance proteins.

Effect of preserved eggs on the health of SD rats, and anti-tumor action of HT-29 cells.

Preserved eggs are traditional alkali-pickled food in China and have been enjoyed by consumers and extensively studied by researchers for their nutritional tastes and their anti-tumor, anti-inflammatory, antioxidant, lipid-lowering, and blood pressure-lowering properties. To study the anti-tumor effects of preserved eggs, this project observed the health on rats, and anti-tumor effects and separated anti-tumor active components on HT-29 cells. SD rats fed for 80 days showed that preserved eggs had no significant effect on weight, food intake, blood pH, liver tissues, or organ indices. Preserved eggs significantly increased blood levels of oxidative stress markers SOD and CAT, decreased MDA levels by 0.46, 0.23, and 0.25 times. Moreover, they also increased the level of IL-2 from 1233 to 1340 pg/mL. Two water-soluble bioactive peptide fractions, B1 and B2, with molecular weights ≥10 kDa were further obtained from preserved eggs by ultrafiltration and Superdex Peptide 10/300 GL. The potential mechanism of B1 and B2 is to activate the internal mitochondrial apoptotic pathway and induce apoptosis by up-regulating the expression of the pro-apoptotic factors cytochrome C, caspase-3, and caspase-9 mRNA in HT-29 cells.

Isolated unilateral oculomotor palsy caused by pure midbrain infarction: a case report.

Purpose: Multiple etiologies may cause oculomotor nerve palsies. Identification of different etiologies is very important for subsequent treatment. Midbrain infarction is a rare cause of oculomotor nerve palsy. Materials and methods: We herein present a case of isolated unilateral oculomotor paresis caused by pure midbrain infarction. Results: Her pupillary sphincter and inferior rectus muscles were selectively spared. The symptoms were completely relieved after two months of antiplatelet therapy. We proposed that fibers from Edinger-Westphal nucleus and inferior rectus nucleus do not course through the paramedian area of the midbrain. Conclusions: Our report adds to the understanding of fascicles arrangement in the midbrain.

Separation of C2H2/C2H4/C2H6 and C2H2/CO2 in a Nitrogen-Rich Copper-Based Microporous Metal-Organic Framework.

The purification of industrially valuable C2H2 and C2H4 from multicomponent mixtures represents a crucial process in the chemical industry. In this study, we present a copper-based metal-organic framework (L-py-Cu) built on a nitrogen-rich organic linker that is capable of separating C2H2/C2H4/C2H6 and C2H2/CO2 mixtures, therefore producing highly pure C2H4 and C2H2, respectively. L-py-Cu exhibits favorable adsorption of C2H2 and C2H6 over C2H4 and thus achieves one-step C2H4 purification from C2H2/C2H4/C2H6 ternary mixtures, as verified by multicomponent breakthrough measurements. In addition, it can also extract C2H2 from C2H2/CO2 binary mixtures.

Temporal trends and geographic variations in perioperative red blood cell transfusion in major surgical procedures from 2013 to 2018 in China.

BACKGROUND AND OBJECTIVES: Transfusion-related guidelines promote restrictive blood transfusion. However, whether these guidelines have been successfully translated into clinical practice in China is unknown. This study aimed to provide updated information about the temporal trends in the prevalence of perioperative red blood cell (RBC) transfusion in China. MATERIALS AND METHODS: We analysed data from the Hospital Quality Monitoring System database (2013-2018) to investigate the prevalence of perioperative RBC transfusion in patients undergoing craniotomy for cerebral aneurysms or arteriovenous malformations, sternotomy for mitral valve replacement, open thoracotomy lobectomy, open gastrectomy and hip arthroplasty. Mixed-effects logistic regression models quantified the likelihood of RBC transfusions. RESULTS: The study included 438,183 patients, with 44,697 (10.20%) receiving perioperative RBC transfusions. Introducing transfusion-related guidelines in China markedly decreased the prevalence of RBC transfusion among patients who underwent major surgical procedures in the following years. The prevalence of RBC transfusion for hip arthroplasty was 17.34% in 2013 and 7.03% in 2018. After adjusting for patient risk factors, the odds ratio of RBC transfusion for hip arthroplasty was significantly lower in 2018 (0.74, 95% confidence intervals [CI] 0.53-1.02) than in 2013 (1.84, 95% CI 1.37-2.48). CONCLUSION: The prevalence of perioperative RBC transfusion decreased from 2013 to 2018 in China, supporting the potential beneficial effects of transfusion-related guidelines. Considering the geographic variations in RBC transfusion, reducing heterogeneity may impact public health by improving surgical outcomes.

Unveiling hepatotoxicity distinction of coumarin-related compounds from glycosides to aglycones in Fructus Psoraleae by integrating UPLC-Q-TOF-MS and high content analysis.

ETHNOPHARMACOLOGICAL RELEVANCE: Fructus Psoraleae (FP), the dried and ripe fruit of Cullen corylifolium (L.) Medik., is widely used due to its various clinical pharmacological effects, but its hepatotoxicity restricts its clinical application. So far, its hepatotoxic components and their underlying mechanism have not been systematically elucidated. AIM OF THE STUDY: This study was undertaken to reveal the hepatotoxicity distinction of coumarin-related compounds from glycosides to aglycones in FP and elucidate their potential mechanism. METHODS: Rats were administrated with the aqueous extract of Fructus Psoraleae (AEFP), in which eight coumarin-related compounds were focused. Subsequently, compounds exposed in rats' livers were detected by UPLC-Q-TOF-MS, and the identified hepatotoxic compounds were evaluated to elaborate their possible mechanism by the aid of high content analysis (HCA). RESULTS: Eight coumarin-related compounds were identified, among which psoralenoside (PO), isopsoralenoside (IPO), psoralen (P), and isopsoralen (IP) were the principally exposed compounds in rats' livers. Furocoumarinic acid glucoside (FAG), (E)-3-(4-(((2S, 3R, 4S, 5S, 6R)-3,4,5-trihydroxy-6-(hydroxymethyl) tetrahydro-2H-pyran-2-yl) oxy) benzofuran-5-yl) acrylic acid (isofurocoumarinic acid glucoside, IFAG), furocoumarinic acid (FA), and (E)-3-(4-hydroxybenzofuran-5-yl) acrylic acid (isofurocoumarinic acid, IFA) were also detected in low abundance. P, IP, FA, and IFA were identified as the hepatotoxic compounds, while their glycosides were almost non-hepatotoxic. The HCA's results showed that hepatotoxic compounds disrupted the balance in reactive oxygen species (ROS), nuclear area, and mitochondrial membrane potential of HepG2 cells, leading to the occurrence of hepatotoxicity. CONCLUSIONS: P, IP, FA, and IFA were identified as hepatotoxic compounds, from which P and IP were proposed as the important risk components for hepatotoxicity. The conversion from glycosides to aglycones played an essential role in FP-induced hepatotoxicity.

Risk factors for postoperative complications after pheochromocytoma and/or paraganglioma: a single-center retrospective study.

Background: Perioperative complications are higher in patients with pheochromocytoma and/or paraganglioma. The aim of this study was to identify the risk factors of postoperative complications after pheochromocytoma and/or paraganglioma resection surgery. Method: We retrospectively reviewed 438 patients who underwent laparoscopic or open surgery for pheochromocytoma and/or paraganglioma at our center between January 2014 and December 2019. Demographic characteristics and intraoperative and postoperative data were recorded. Complications were defined as deviations from the normal postoperative course and Clavien-Dindo classification was used to grade the severity of postoperative complication. Patients with complications of grade II or above were included for analysis. Binary logistic regression was used to determine the risk factors for postoperative complications. Results: The median age of the patients was 47 years old. There were 295 cases (67.4%) of phepchromocytoma and 143 cases (32.6%) of paraganglioma. Three hundred sixty-seven (87.8%) patients had laparoscopic approach, and 55 (12.6%) patients had laparotomy; the conversion rate from laparoscopy to laparotomy was 3.7%. Eighty-seven complications occurred in 65 patients (14.8%). No death occurred in our study and transfusion (36, 8.2%) was the most common complication. The mean follow-up length was 14 months. Independent risk factors for postoperative complications included a tumor size larger than 5.6 cm (OR = 2.427, 95% CI 1.284-4.587, P = 0.006), laparotomy (OR 2.590, 95% CI 1.230-5.453, P = 0.012), conversion to laparotomy (OR = 8.384, 95% CI 2.247-31.285, P = 0.002), and the operation time longer than 188 min (OR = 3.709, 95% CI 1.847-7.450, P < 0.001). Conclusion: Complications were not uncommon after pheochromocytoma and/or paraganglioma surgery. Tumor size, surgical type, and operation time were determined as the risk factors for postoperative complications. These factors should be considered to improve perioperative management.

Individualized red-cell transfusion strategy for non-cardiac surgery in adults: a randomized controlled trial.

BACKGROUND: Red-cell transfusion is critical for surgery during the peri-operative period; however, the transfusion threshold remains controversial mainly owing to the diversity among patients. The patient's medical status should be evaluated before making a transfusion decision. Herein, we developed an individualized transfusion strategy using the West-China-Liu's Score based on the physiology of oxygen delivery/consumption balance and designed an open-label, multicenter, randomized clinical trial to verify whether it reduced red cell requirement as compared with that associated with restrictive and liberal strategies safely and effectively, providing valid evidence for peri-operative transfusion. METHODS: Patients aged >14 years undergoing elective non-cardiac surgery with estimated blood loss > 1000 mL or 20% blood volume and hemoglobin concentration <10 g/dL were randomly assigned to an individualized strategy, a restrictive strategy following China's guideline or a liberal strategy with a transfusion threshold of hemoglobin concentration <9.5 g/dL. We evaluated two primary outcomes: the proportion of patients who received red blood cells (superiority test) and a composite of in-hospital complications and all-cause mortality by day 30 (non-inferiority test). RESULTS: We enrolled 1182 patients: 379, 419, and 384 received individualized, restrictive, and liberal strategies, respectively. Approximately 30.6% (116/379) of patients in the individualized strategy received a red-cell transfusion, less than 62.5% (262/419) in the restrictive strategy (absolute risk difference, 31.92%; 97.5% confidence interval [CI]: 24.42-39.42%; odds ratio, 3.78%; 97.5% CI: 2.70-5.30%; P <0.001), and 89.8% (345/384) in the liberal strategy (absolute risk difference, 59.24%; 97.5% CI: 52.91-65.57%; odds ratio, 20.06; 97.5% CI: 12.74-31.57; P <0.001). No statistically significant differences were found in the composite of in-hospital complications and mortality by day 30 among the three strategies. CONCLUSION: The individualized red-cell transfusion strategy using the West-China-Liu's Score reduced red-cell transfusion without increasing in-hospital complications and mortality by day 30 when compared with restrictive and liberal strategies in elective non-cardiac surgeries. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01597232.

Exploring the influence of ultrasound on the antibacterial emulsification stability of lysozyme-oregano essential oil.

A lysozyme-oregano essential oil (Lys-OEO) antibacterial emulsion was developed via ultrasonic treatment. Based on the general emulsion materials of ovalbumin (OVA) and inulin (IN), the addition of Lys and OEO successfully inhibited the growth of E. coli and S. aureus, two representatives of which were Gram-negative and Gram-positive bacteria respectively. The emulsion system in this study was designed to compensate for the limitation that Lys could only act on Gram-positive bacteria, and the stability of the emulsion was improved using ultrasonic treatment. The optimal amounts among OVA, Lys and OEO were found to be the mass ratio of 1:1 (Lys to OVA) and 20% (w/w) OEO. The ultrasonic treatment at the power of 200, 400, 600, and 800 W and time length of 10 min improved the stability of emulsion, in which the surface tension was below 6.04 mN/m and the Turbiscan stability index (TSI) did not exceed 10. The multiple light scattering showed that sonicated emulsions were less prone to delamination; salt stability and pH stability of emulsions were improved, CLSM image showed emulsion as oil-in-water type. In the meantime, the particles of the emulsions were found to become smaller and more uniform with ultrasonic treatment. The best dispersion and stability of the emulsion were both achieved at 600 W with a zeta potential of 7.7 mV, the smallest particle size and the most uniform particle distribution.

Elastic and transparent ovalbumin hydrogels formed via succinylation combined with pH-shifting treatment.

Ovalbumin (OVA) is a model protein with extensive research on structure and function, however, the application of OVA in food processing is limited due to its low gelation properties. In this study, thermally-induced highly transparent and elastic hydrogels from OVA pretreated by succinylation combined with pH-shifting method were reported. Transmission electron microscope (TEM) and free sulfhydryl groups determination revealed that the pretreatment induced the stretching of the protein structure and promoted the formation of preliminary aggregates. Further heating the pretreated OVA suspension resulted in a homogeneous and macroporous gel network with thin connecting walls. Such homogeneous gel network structures may be related to the effective modulation of the thermal aggregation efficiency of proteins by succinylation and the high level of protein unfolding by pH-shifting treatments, which synergistically allowed for more active sites to be created during heating to facilitate intermolecular interactions, including hydrogen bonding and hydrophobic interactions. Notably, the method resulted in a 507.14% increase in elasticity, a 60.74% increase in water holding capacity of the OVA hydrogels compared to the native OVA hydrogels without pretreatment. Also, the hydrogels were transparent with 73.11% light transmittance. In conclusion, succinylation and pH-shifting combined treatment could be an effective method for the preparation of OVA hydrogels with superior gelation properties.

Structures of MPND Reveal the Molecular Recognition of Nucleosomes.

Adenine N6 methylation in DNA (6mA) is a well-known epigenetic modification in bacteria, phages, and eukaryotes. Recent research has identified the Mpr1/Pad1 N-terminal (MPN) domain-containing protein (MPND) as a sensor protein that may recognize DNA 6mA modification in eukaryotes. However, the structural details of MPND and the molecular mechanism of their interaction remain unknown. Herein, we report the first crystal structures of the apo-MPND and MPND-DNA complex at resolutions of 2.06 Å and 2.47 Å, respectively. In solution, the assemblies of both apo-MPND and MPND-DNA are dynamic. In addition, MPND was found to possess the ability to bind directly to histones, no matter the N-terminal restriction enzyme-adenine methylase-associated domain or the C-terminal MPN domain. Moreover, the DNA and the two acidic regions of MPND synergistically enhance the interaction between MPND and histones. Therefore, our findings provide the first structural information regarding the MPND-DNA complex and also provide evidence of MPND-nucleosome interactions, thereby laying the foundation for further studies on gene control and transcriptional regulation.

Structures of human TR4LBD-JAZF1 and TR4DBD-DNA complexes reveal the molecular basis of transcriptional regulation.

Testicular nuclear receptor 4 (TR4) modulates the transcriptional activation of genes and plays important roles in many diseases. The regulation of TR4 on target genes involves direct interactions with DNA molecules via the DNA-binding domain (DBD) and recruitment of coregulators by the ligand-binding domain (LBD). However, their regulatory mechanisms are unclear. Here, we report high-resolution crystal structures of TR4DBD, TR4DBD-DNA complexes and the TR4LBD-JAZF1 complex. For DNA recognition, multiple factors come into play, and a specific mutual selectivity between TR4 and target genes is found. The coactivators SRC-1 and CREBBP can bind at the interface of TR4 originally occupied by the TR4 activation function region 2 (AF-2); however, JAZF1 suppresses the binding through a novel mechanism. JAZF1 binds to an unidentified surface of TR4 and stabilizes an α13 helix never reported in the nuclear receptor family. Moreover, the cancer-associated mutations affect the interactions and the transcriptional activation of TR4 in vitro and in vivo, respectively. Overall, our results highlight the crucial role of DNA recognition and a novel mechanism of how JAZF1 reinforces the autorepressed conformation and influences the transcriptional activation of TR4, laying out important structural bases for drug design for a variety of diseases, including diabetes and cancers.

A critical review of on-site inorganic arsenic screening methods.

Approximately 94 to 220 million people worldwide are at risk of drinking well water containing arsenic > 10 µg/L, the WHO guideline value. To identify non-compliant domestic wells, assess health risks and reduce exposure, accurate and rapid on-site inorganic arsenic screening methods are desirable because all domestic wells worldwide need to be tested. Here, the principles, advantages and limitations of commonly used colorimetry, electrochemistry, and biosensing methods are critically reviewed, with the performance compared with laboratory-based benchmark methods. Most commercial kits are based on the classic Gutzeit reaction. Despite being semi-quantitative, the more recent and more expensive products display improved and acceptable accuracy and shorter testing time (∼10 min). Carried out by trained professionals, electrochemical methods are also feasible for on-site analysis, although miniaturization is desirable yet challenging. Biosensing using whole bacterial cells or bio-engineered materials such as aptamers is promising, if incorporated with function specific nanomaterials and biomaterials. Since arsenic is frequently found as arsenite in reducing groundwater and subject to oxidation during sampling, transportation and storage, on-site separation and sample preservation are feasible but the specific methods should be chosen based on sample matrix and tested before use. To eliminate arsenic exposure among hundreds of millions of mostly rural residents worldwide, we call for concerted efforts in research community and regulatory authority to develop accurate, rapid, and affordable tests for on-site screening and monitoring of arsenic in drinking water. Access to affordable testing will benefit people who are socioeconomically disadvantaged.