Transcription factor ZmWRKY20 interacts with ZmWRKY115 to repress expression of ZmbZIP111 for salt tolerance in maize.

Maize (Zea mays) is an important cereal crop worldwide. However, its yield and quality are adversely affected by salt stress resulting from soil hypersalinity. Exploring the regulatory mechanisms of stress responses is of vital importance to increase maize seed production. In the present study, we screened ethyl methanesulfonate-induced maize mutants and identified a salt-tolerant mutant. A single base was mutated in ZmWRKY20, leading to the formation of a truncated protein variant. A detailed phenotypic analysis revealed that this mutant had significantly higher resistance to wilting and lower reactive oxygen species levels than the inbred line B73. ZmWRKY20 showed transcriptional activity in yeast and specifically bound W-boxes according to the results of our yeast one-hybrid, electrophoretic mobility shift, and dual-luciferase assays. Overexpression of ZmWRKY20 decreased salt tolerance in maize. Transcriptome profiling revealed that ZmWRKY20 overexpression extensively reprogrammed genes involved in regulating defense and oxidation-reduction responses. The results substantiate that ZmWRKY20 is directly targeted to the basic leucine zipper (bZIP) motif in the transcription factor ZmbZIP111. It was also verified that ZmWRKY20 interacts with ZmWRKY115 and both proteins act jointly to enhance ZmbZIP111 repression. The results indicate that the ZmWRKY20 and ZmWRKY115 transcription factors interact in the nucleus, leading to repression of ZmbZIP111 expression by directly binding its promoter, and increase the sensitivity of maize seedlings to salt stress. The current study improves our understanding of the complicated responses of maize to salt stress.

[A preliminary study on a new method for evaluating brain maturation in preterm infants]. / ä¸€ç§æ–°çš„æ—©äº§å„¿è„‘ç”µå‘è‚²æˆç†Ÿåº¦è¯„ä»·æ–¹æ³•çš„åˆæ­¥ç ”ç©¶.

OBJECTIVES: To establish a new method for evaluating the brain maturation of preterm infants based on the features of electroencephalographic activity. METHODS: A prospective study was conducted on the video electroencephalography (vEEG) and amplitude-integrated electroencephalography (aEEG) recordings within 7 days after birth of preterm infants who had a postmenstrual age (PMA) of 25-36 weeks and met the inclusion criteria. The background activity of aEEG+conventional electroencephalography (cEEG) was scored according to the features of brain maturation as a new evaluation system and was compared with the aEEG evaluation system. The correlations of the evaluation results of the two methods with gestational age (GA), PMA, and head circumference were evaluated. The intervals of the total scores of aEEG+cEEG and aEEG were calculated for preterm infants with different PMAs and were compared between groups. The consistency of the new scoring system was evaluated among different raters. RESULTS: A total of 52 preterm infants were included. The total scores of aEEG+cEEG and aEEG were positively correlated with GA, PMA, and head circumference (P<0.05), and the correlation coefficient between the total scores of the two systems and PMA and GA was >0.9. The normal score intervals for aEEG+cEEG and aEEG scoring systems were determined in preterm infants with different PMAs as follows: infants with a PMA of less than 28 weeks had scores of 13.0 (11.0, 14.0) points for aEEG+cEEG and 6.0 (4.0, 7.0) points for aEEG; infants with a PMA between 28 and 29+6 weeks had scores of 16.0 (14.5, 17.0) points for aEEG+cEEG and 8.0 (6.0, 8.0) points for aEEG; infants with a PMA between 30 and 31+6 weeks had scores of 18.0 (17.0, 21.0) points for aEEG+cEEG and 9.0 (8.0, 10.0) points for aEEG; infants with between 32 and 33+6 weeks had scores of 22.0 (20.0, 24.5) points for aEEG+cEEG and 10.0 (10.0, 10.8) points for aEEG; infants with a PMA between 34 and 36 weeks had scores of 26.0 (24.5, 27.5) points for aEEG+cEEG and 11.0 (10.0, 12.0) points for aEEG. There were significant differences in the total scores of aEEG+cEEG and aEEG among the different PMA groups (P<0.05). There was a high consistency between different raters when using the scoring system to evaluate the brain maturation of preterm infants (κ=0.86). CONCLUSIONS: The aEEG+cEEG scoring system established in this study can quantitatively reflect the brain maturation of preterm infants, with a good discriminatory ability between preterm infants with different PMAs and high consistency between different raters.

[A novel method for electroencephalography background analysis in neonates with hypoxic-ischemic encephalopathy]. / åº”ç”¨äºŽæ–°ç”Ÿå„¿ç¼ºæ°§ç¼ºè¡€æ€§è„‘ç— çš„è„‘ç”µèƒŒæ™¯åˆ†æžæ–°æ–¹æ³•.

OBJECTIVES: To explore a new method for electroencephalography (EEG) background analysis in neonates with hypoxic-ischemic encephalopathy (HIE) and its relationship with clinical grading and head magnetic resonance imaging (MRI) grading. METHODS: A retrospective analysis was performed for the video electroencephalography (vEEG) and amplitude-integrated electroencephalography (aEEG) monitoring data within 24 hours after birth of neonates diagnosed with HIE from January 2016 to August 2022. All items of EEG background analysis were enrolled into an assessment system and were scored according to severity to obtain the total EEG score. The correlations of total EEG score with total MRI score and total Sarnat score (TSS, used to evaluate clinical gradings) were analyzed by Spearman correlation analysis. The total EEG score was compared among the neonates with different clinical gradings and among the neonates with different head MRI gradings. The receiver operating characteristic (ROC) curve and the area under thecurve (AUC) were used to evaluate the value of total EEG score in diagnosing moderate/severe head MRI abnormalities and clinical moderate/severe HIE, which was then compared with the aEEG grading method. RESULTS: A total of 50 neonates with HIE were included. The total EEG score was positively correlated with the total head MRI score and TSS (rs=0.840 and 0.611 respectively, P<0.001). There were significant differences in the total EEG score between different clinical grading groups and different head MRI grading groups (P<0.05). The total EEG score and the aEEG grading method had an AUC of 0.936 and 0.617 respectively in judging moderate/severe head MRI abnormalities (P<0.01) and an AUC of 0.887 and 0.796 respectively in judging clinical moderate/severe HIE (P>0.05). The total EEG scores of ≤6 points, 7-13 points, and ≥14 points were defined as mild, moderate, and severe EEG abnormalities respectively, which had the best consistency with clinical grading and head MRI grading (P<0.05). CONCLUSIONS: The new EEG background scoring method can quantitatively reflect the severity of brain injury and can be used for the judgment of brain function in neonates with HIE.

Correlation of electroencephalogram background evolution with the degree of brain injury in neonates with hypoxic-ischemic encephalopathy. / æ–°ç”Ÿå„¿ç¼ºæ°§ç¼ºè¡€æ€§è„‘ç— è„‘ç”µèƒŒæ™¯æ¼”å˜ä¸Žè„‘æŸä¼¤ç¨‹åº¦çš„ç›¸å ³æ€§ç ”ç©¶.

OBJECTIVES: To study the correlation of electroencephalogram (EEG) background evolution with the degree of brain injury in neonates with hypoxic-ischemic encephalopathy (HIE). METHODS: A retrospective analysis was performed for 56 neonates with HIE who underwent continuous video electroencephalogram (cVEEG) and brain magnetic resonance imaging (MRI) examinations. According to clinical symptoms, they were divided into a mild group with 3 neonates, a moderate group with 36 neonates, and a severe group with 17 neonates. EEG background grading and MRI score were determined for each group to analyze the correlation of EEG background evolution with the degree of brain injury. RESULTS: Compared with the moderate group, the severe group had significantly lower gestational age and Apgar score at 5 minutes after birth, a significantly higher resuscitation score, significantly lower base excess in umbilical cord blood or blood gas within 1 hour, a significantly higher proportion of neonates on mechanical ventilation, and a significantly higher incidence rate of short-term adverse outcomes (P<0.05). For the neonates in the mild and moderate groups, MRI mainly showed no brain injury (67%, 2/3) and watershed injury (67%, 16/24) respectively, and EEG showed mild abnormality in 62% (13/21) of the neonates on the 3rd day after birth. For the neonates in the severe group, MRI mainly showed basal ganglia/thalamus + brainstem injury (24%, 4/17) and whole brain injury (71%, 12/17), and EEG showed moderate or severe abnormalities on the 3rd day after birth. EEG background grading was correlated with clinical grading, MRI score, and short-term outcome on days 1, 2, 3 and 7-14 after birth (P<0.01). The highest correlation coefficient between EEG grading and MRI score was observed on the 3rd day after birth (rs=0.751, P<0.001), and the highest correlation coefficients between EEG grading and clinical grading (rs=0.592, P=0.002) and between EEG grading and short-term outcome (rs=0.737, P<0.001) were observed 7-14 days after birth. Among the neonates with severe abnormal EEG, the neonates without brain electrical activity had the highest MRI score, followed by those with status epileptics and persistent low voltage (P<0.05). CONCLUSIONS: There is a good correlation between EEG background grading and degree of brain injury in neonates with HIE, which can help to evaluate the degree and prognosis of brain injury in the early stage.

Investigation of hairpin DNA and chelerythrine interaction by a single bio-nanopore sensing interface.

Chelerythrine (CHE) is one of the potential drugs for cancer treatments. The interaction between hairpin DNA and CHE has been investigated by spectral and mass spectrometry methods. In this paper, the stability of hairpin DNA with different loop bases and its interaction with CHE were explored with a single α-hemolysin (α-HL) nanopore sensing interface. The results showed that the characteristic current pulses not only relate to the loop composition changes of the hairpin DNA, but also provide interaction information between CHE and the hairpin DNA molecules. The dwell time of current pulses for hairpin DNA was significantly increased (hundreds of ms) due to the addition of CHE, and two characteristic current distributions were recognized for the hairpin with T3 and C3 loops. The two characteristic current groups could be ascribed to the hairpin DNA and the ones with CHE. This study indicates that it is possible to study the interaction between single CHE and single hairpin DNA molecules by the single-nanopore sensing interface as an alternative method to conventional spectrometric methods for therapeutic mechanism and drug screening purposes.

Defining the regulatory role of programmed cell death 4 in laryngeal squamous cell carcinoma.

Programmed cell death 4 (PDCD4) is decreased in many different kinds of malignant tumors. EMT endows tumor cells invasive and metastatic properties. However, few studies have determined the role of PDCD4 in the regulation of EMT in the context of laryngeal carcinoma. We examined the relationship between PDCD4 and EMT-associated proteins E-cadherin and N-cadherin using laryngeal carcinoma tissues. Gene manipulation was used to define the regulatory capacity of PDCD4. We report that PDCD4 and E-cadherin/N-cadherin expression were significantly changed in the carcinoma tissues, and their expression was associated with pathological grade, metastatic state, and clinical stage. The suppression of PDCD4 (and consequently, E-cadherin) was concomitant with increased proliferation and G2-phase arrest, decreased apoptosis, and increased cell invasion. PDCD4 upregulation reversed the above-mentioned results. In nude mice, PDCD4 knockdown increased tumor growth and pathological features, confirming the tumorigenic role of PDCD4. Finally, PDCD4 silencing was associated with dysregulation of the carcinogenic Wnt-ß-catenin and the STAT3-miR-21 signaling pathways. This study revealed a dynamic regulatory relationship between PDCD4 and critical factors for EMT, establishing a broad, functional role for PDCD4 in laryngeal carcinoma, which may be propagated by the STAT3-miR-21 pathway. These findings provide new information on an EMT-associated target that may lead to a novel therapy.

G3BP2 is involved in isoproterenol-induced cardiac hypertrophy through activating the NF-κB signaling pathway.

The RasGAP SH3 domain-binding proteins (G3BPs) are a family of RNA-binding proteins that can co-ordinate signal transduction and post-transcriptional gene regulation. G3BPs have been shown to be involved in mediating a great diversity of cellular processes such as cell survival, growth, proliferation and apoptosis. But the potential roles of G3BPs in the pathogenesis and progression of cardiovascular diseases remain to be clarified. In the present study, we provide the first evidence that suggests the participation of G3BP2 in cardiac hypertrophy. In cultured neonatal rat cardiomyocytes (NRCMs), treatment with isoproterenol (ISO, 0.1-100 µmol/L) significantly elevated the mRNA and protein levels of G3BP2. Similar results were observed in the hearts of rats subjected to 7D-injection of ISO, accompanied by obvious heart hypertrophy and elevated the expression of hypertrophy marker genes ANF, BNP and ß-MHC in heart tissues. Overexpression of G3BP2 in NRCMs led to hypertrophic responses evidenced by increased cellular surface area and the expression of hypertrophy marker genes, whereas knockdown of G3BP2 significantly attenuated ISO-induced hypertrophy of NRCMs. We further showed that G3BP2 directly interacted with IκBα and promoted the aggregation of the NF-κB subunit p65 in the nucleus and increased NF-κB-dependent transcriptional activity. NF-κB inhibition with PDTC (50 µmol/L) or p65 knockdown significantly decreased the hypertrophic responses in NRCMs induced by ISO or G3BP2 overexpression. These results give new insight into the functions of G3BP2 and may help further elucidate the molecular mechanisms underlying cardiac hypertrophy.

Production of a new non-specific nuclease from Yersinia enterocolitica subsp. palearctica: optimization of induction conditions using response surface methodology.

A new non-specific nuclease from Yersinia enterocolitica subsp. palearctica (Y. NSN) was expressed in Escherichia coli (E. coli) BL 21 StarTM (DE3)plysS. Induction conditions, including isopropyl-ß-D-thiogalactoside (IPTG) concentration, cell density (OD600), induction time and induction temperature, were optimized using response surface methodology. Statistical analysis of the results revealed that induction temperature and all the quadratic terms of variables had significant effects on enzyme activity of Y. NSN. The optimal induction conditions were as follows: 1.5 mmol/L IPTG, OD600 of 0.80, induction time of 20.5 h, and induction temperature of 32 °C. Under the optimized conditions, the highest enzyme activity could be obtained.

The WRKY transcription factor ZmWRKY92 binds to GA synthesis-related genes to regulate maize plant height.

The plant height is a crucial agronomic trait in contemporary maize breeding. Appropriate plant height can improve crop lodging resistance, increase the planting density and harvest index of crops, and thus contribute to stable and increased yields. In this study, molecular characterization showed that ZmWRKY92 is a nuclear protein and has transcriptional activation in yeast. ZmWRKY92 can specifically bind to the W-box (TTGACC), which was confirmed by double LUC experiments and Yeast one-hybrid assays. Subsequently we screened wrky92 mutants from a library of ethyl methanesulfonate (EMS)-induced mutants. The mutation of a base in ZmWRKY92 leading to the formation of a truncated protein variant is responsible for the dwarfing phenotype of the mutant, which was further verified by allelic testing. Detailed phenotypic analysis revealed that wrky92 mutants have shorter internodes due to reduced internode cell size and lower levels of GA3 and IAA. Transcriptome analysis revealed that the ZmWRKY92 mutation caused significant changes in the expression of genes related to plant height in maize. Additionally, ZmWRKY92 was found to interact with the promoters of ZmGA20ox7 and ZmGID1L2, which are associated with GA synthesis. This study shows that ZmWRKY92 significantly affects the plants height in maize and is crucial in identifying new varieties suitable for growing in high-density conditions.

Synthesis and anti-inflammatory activity of mogrol derivatives modified at C24 site.

Mogrol, the aglycone of well-known sweeter mogrosides, shows potent anti-inflammatory activity. In this study, forty-two mogrol derivatives bearing various pharmacophores with oxygen or nitrogen atoms were designed and synthesized via structural modification at C24 site, and their anti-inflammatory activity were screened against lipopolysaccharide (LPS)-induced RAW264.7 cells. Compared with mogrol, most of derivatives exhibited stronger inhibition of NO production without cytotoxicity. In particular, compound B5 that contained an indole motif effectively suppressed the secretion of inflammatory mediators including TNF-α and IL-6, and inhibited the expression levels of TLR4, p-p65 and iNOS proteins. Molecular docking showed that the active B5 interacted with amino acid residues of iNOS protein through π-π stacking and hydrophobic interactions with binding affinity value of -12.1 kcal/mol, which was much stronger than mogrol (-8.9 kcal/mol). These results suggest that derivative B5 is a promising anti-inflammatory molecule and the strategy of hybridizing indole skeleton on mogrol is worthy for further attention.

The Impact of Vp-Porin, an Outer Membrane Protein, on the Biological Characteristics and Virulence of Vibrio Parahaemolyticus.

Porins are crucial proteins located in the outer membrane that directly influence antimicrobial resistance mechanisms and virulence in bacteria. In this study, a porin gene (Vp-porin) was cloned in V. parahaemolyticus, and the function of Vp-Porin in biological characteristics and virulence was investigated. The results of sequence analysis showed that Vp-Porin is highly conserved in Vibrio spp., and the predicted 3D structure showed it could form a 20-strand transmembrane ß-barrel domian. Membrane permeabilization provides evidence that the membrane integrity of ∆Vp-porin was damaged and the sensitivity to tetracycline, polymyxin B, rifampicin and cephalothin of ∆Vp-porin obviously increased. In addition, loss of Vp-porin damaged motility due to downregulated flagellar synthesis. In addition, ∆Vp-porin exhibited attenuated cytotoxicity to Tetrahymena. The relative survival rate of Tetrahymena infection with ∆Vp-porin was 86%, which is much higher than that with WT (49%). Taken together, the results of this study indicate that Vp-Porin in V. parahaemolyticus plays various roles in biological characteristics in membrane integrity, antimicrobial resistance and motility and contributes to virulence.

Noninvasive prenatal testing for the detection of fetal chromosome 17 microduplication: clinical implications and findings.

BACKGROUND:  Noninvasive prenatal testing (NIPT) is widely used to screen for fetal aneuploidies. However, there are few reports of using NIPT for screening chromosomal microduplications and microdeletions. This study aimed to investigate the application efficiency of NIPT for detecting chromosomal microduplications. METHODS: Four cases of copy number gains on the long arm of chromosome 17 (17q12) were detected using NIPT and further confirmed using copy number variation (CNV) analysis based on chromosome microarray analysis (CMA). RESULTS: The prenatal diagnosis CMA results of the three cases showed that the microduplications in 17q12 (ranging from 1.5 to 1.9 Mb) were consistent with the NIPT results. The karyotypic analysis excluded other possible unbalanced rearrangements. The positive predictive value of NIPT for detecting chromosomal 17q12 microduplication was 75.0%. CONCLUSIONS:  NIPT has a good screening effect on 17q12 syndrome through prenatal diagnosis, therefore it could be considered for screening fetal CNV during the second trimester. With the clinical application of NIPT, invasive prenatal diagnoses could be effectively reduced while also improving the detection rate of fetal CNV.

Temperature can influence gastric accommodation and sensitivity in functional dyspepsia with epigastric pain syndrome.

BACKGROUND: Functional dyspepsia-epigastric pain syndrome (FD-EPS) is characterized pathophysiologically by visceral hypersensitivity, but the effect of the temperature stimulation on gastric function has been seldom studied. AIM: The purpose of this study was to investigate the effects of liquid nutrients at different temperatures on the gastric accommodation, sensitivity, and gastric-wall compliance of healthy subjects (HS) and FD-EPS patients. METHODS: Ten FD-EPS patients (Roma III criteria) and ten HS were recruited into the study. Intragastric pressure (IGP) and gastric perfusion were measured and compared following the administration of liquid nutrients at 37 °C on day 1 and at 8 °C on day 2. RESULTS: Seven patients developed abdominal discomfort or abdominal pain after being given cold liquid nutrient. The administration of liquid nutrient at 8 °C resulted in an increase of IGP in HS (P=0.044), a significant decrease in gastric perfusion (P<0.0001), a marked increase in IGP (P=0.015), and a dramatic reduction in gastric wall compliance (P=0.012) in patients compared to the effects of liquid nutrient at 37 °C. In addition, IGP in patients was lower than that in HS at 37 °C liquid nutrient (P=0.036), and the gastric perfusion volume in patients at maximal satiety was also significantly reduced at 8 °C liquid nutrient compared with HS (P=0.017). CONCLUSIONS: Cold stimulation can increase the IGP in HS and FD-EPS patients, elevate the visceral sensitivity and reduce the gastric volume of FD-EPS patients. FD-EPS patients who are sensitive to cold may develop epigastric discomfort or pain.

Encapsulation in alginate-skim milk microspheres improves viability of Lactobacillus bulgaricus in stimulated gastrointestinal conditions.

Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus) was encapsulated in alginate-skim milk microspheres. Characteristics of encapsulated L. bulgaricus, such as pH stability, bile stability, storage stability and release property, were studied in this paper. The viability of free L. bulgaricus was not observed after 1 min in simulated gastric fluids (SGF) at pH 2.5 or 2.0. Compared with that of free L. bulgaricus, the viability of encapsulated L. bulgaricus only decreased 0.7 log CFU/g and 2 log CFU/g after 2.0 h incubation in SGF at pH 2.5 and pH 2.0, respectively. L. bulgaricus was also sensitive to bile solution. The viability of free L. bulgaricus was fully lost after 1 h incubation in 1 and 2% bile solution, while the viability of encapsulated L. bulgaricus was only lost 2 log CFU/g and 2.6 log CFU/g in 1 and 2% bile solution at the same time, respectively. Encapsulated L. bulgaricus could be completely released from microspheres in simulated intestinal fluid (pH 6.8) within 2 h. The viability of encapsulated L. bulgaricus retained around 8 log CFU/g when stored at 4°C for 30 days. The current encapsulation technique enables a large proportion of L. bulgaricus to remain good bioactive in a simulated gastrointestinal tract environment.

[Risk factors for delirium of elderly patients undergoing hip fracture operation].

OBJECTIVE: To explore the causes for delirium of elderly patients after hip fracture operation. METHODS: A total of 68 cases of delirium were selected from 458 patients aged over 65 years undergoing hip fracture operation via spinal anesthesia from 2009 to 2011. There were 26 males and 42 females with an average age of 72.9 (66-98) years. Their clinical features, such as gender, operative duration, blood loss volume, saturation of arterial oxygen, were observed. After single factor risk analysis, multiple factor analysis was performed by binary Logistic regression. RESULTS: Delirium occurred at certain timepoints during the first postoperative days. The incidence of delirium was 14.9%. The Logistic stepwise regression analysis showed that significant differences existed between delirium and non-delirium in age (P = 0.042), operative duration (P = 0.042), blood loss volume (P = 0.027), hypoxemia (P = 0.019) and preoperative comorbidity (P = 0.029). CONCLUSION: The independent risk factors for postoperative delirium include age, operative duration, blood loss volume, preoperative comorbidity and hypoxemia.

[Clinical outcomes of percutaneous kyphoplasty under local anesthesia for osteoporotic vertebral compression fractures].

OBJECTIVE: To analyze the clinical outcomes of percutaneous kyphoplasty under local anesthesia for osteoporotic vertebral compression fractures. METHODS: In this study, 76 elderly patients with osteoporotic vertebral compression fractures undergoing percutaneous kyphoplasty were followed up for 2-3.1 years. They were divided into 3 groups according to different ages: 60-69 yrs (A group), 70-79 yrs (B group) and 80- 91 yrs (C group). Pre- and post-operative and last follow-up evaluations were conducted. And the parameters of bone mineral density (BMD), kyphotic angle, change of visual analog scale (VAS), Oswestry disability index, average vertebral body height, complications and costs of hospitalization were recorded and analyzed. RESULTS: BMD decreased with advancing age and had statistical significance between three groups (P < 0.05). Three thoracic spine fractures and 6 lumbar spine fractures could not be detected with digital radiography and were observed only on magnetic resonance imaging (MRI). The pre-operative levels of visual analogue scale and Oswestry disability index increased in all groups.No statistical significance existed between A and B groups. But there was statistical significance between A or B and C groups (P < 0.05). Pre- and post-operative assessments showed that statistically significant improvements were found in visual analogue scale and Oswestry disability index in all groups (P < 0.05). And statistically significant improvements were found for the pre- and post-operative kyphotic angles and vertebral body heights in A, C group and B groups (P < 0.05). The sites for symptomatic leakage of cement included paravertebral vein (n = 2), intervertebral disc (n = 1) and paravertebral space (n = 2). Adjacent vertebral fracture occurred in 1 patient at 17 months and underwent percutaneous kyphoplasty. The mean operative duration was 28 minutes per vertebrae and the mean cost of hospitalization at RMB yuan 33 778. CONCLUSION: As a simple and safe procedure for osteoporotic vertebrae compression fractures, percutaneous kyphoplasty may relieve pain quickly, restore vertebral height, prevent further fractures and improve the patient's quality-of-life.

ß-Cyclodextrin network crosslinked by novel phosphonium-based tetrakiscarboxylic acid derived from PH3 tail gas: Synthesis and application for rapid removal of organic dyes from wastewater.

Organic dyes, such as methyl orange (MO), Congo red (CR), crystal violet (CV) and methylene blue (MB), are common organic pollutants existing in wastewater. Therefore, the exploration of bio-based adsorbents for the efficient removal of organic dyes from wastewater has gained many attentions. Here, we report a PCl3-free synthetic method for the synthesis of phosphonium-containing polymers, in which the prepared tetrakis(2-carboxyethyl) phosphonium chloride-crosslinked ß-cyclodextrin (TCPC-ß-CD) polymers were applied to the removal of dyes from water. The effects of contact time, pH (1-11), and dye concentration were investigated. The selected dye molecules could be captured by the host-gest inclusion of ß-CD cavities, and the phosphonium and carboxyl groups in the polymer structure would respectively facilitate the removal of cationic dyes (MB and CV) and anionic dyes (MO and CR) via electrostatic interactions. In a mono-component system, over 99 % of MB could be removed from water within the first 10 min. Based on the Langmuir model, the calculated maximum adsorption capacities of MO, CR, MB, and CV were 180.43, 426.34, 306.57, and 470.11 mg/g (or 0.55, 0.61, 0.96 and 1.15 mmol/g), respectively. Additionally, TCPC-ß-CD was easily regenerated using 1 % HCl in ethanol, and the regenerative adsorbent still showed high removal capacities for MO, CR, and MB even after seven treatment cycles.

SERS detection of thiram using polyacrylamide hydrogel-enclosed gold nanoparticle aggregates.

The development of sensitive and long-term signal-stable plasmonic substrates is vital to the in-field application of the surface-enhanced Raman spectroscopy (SERS) technique. The colloidal gold nanoparticles (AuNPs) system is commonly used in SERS detection, but it shows less signal stability and reproducibility due to the uncontrollable aggregation of nanoparticles by adding aggregating agents in SERS detection. In this study, we developed a new SERS detection platform based on polyacrylamide hydrogel-enclosed plasmonic gold nanoparticle aggregates (PAH-AuANs). In the system, the formation of PAH can rapidly stabilize the gold nanoparticle aggregates, avoiding the over-aggregation or precipitation of AuNPs. With the PAH concentration in the range of 6-10 % and AuNPs at the concentration of 0.2 nM, the resulting PAH-AuNAs platform exhibited both sensitive SERS activity and excellent SERS signal stability. The relative standard deviation of the 4-MBA probe SERS signal collected from the PAH-AuNAs platform was lower than 3 %. The limit of detection for the pesticide thiram was down to 0.38 µg/L with a handheld Raman spectrometer. Moreover, the procedure for preparing the PAH-AuNAs platform was easy to handle, offering a new strategy for in-field detection of environmental contaminants with a handheld Raman spectrometer in the future.

On-site detection of chloramphenicol in fish using SERS-based magnetic aptasensor coupled with a handheld Raman spectrometer.

In recent years, the rapid detection of chloramphenicol (CAP) has become a market demand due to its high toxicity. In this study, for the first time, a portable surface-enhanced Raman scattering (SERS) aptasensor for the rapid and on-site detection of chloramphenicol (CAP) residues in fish was developed. Fe3O4@Au nanoflowers combined with sulfhydryl (SH)-CAP aptamer complementary DNA acted as capture probes. SH-CAP aptamer modified Au@Ag nanoparticles (Au@Ag NPs) embedded with 4-mercaptobenzoic acid (4-MBA) were served as reporter probes. The strongest Raman intensity was produced due to the coupling of Fe3O4@Au nanoflowers (Fe3O4@Au NFs) and Au@Ag NPs. For CAP detection, a wide linear range from 0.001 to 1000 µg/L, with an R2 of 0.9805, was obtained. The limit of detection was determined to be 0.87 ng/L. The SERS aptasensor showed excellent performance for analytical applications for real fish samples. Compared with the conventional HPLC method, the developed SERS aptasensor coupled with a handheld Raman spectrometer had flexible application and avoided the limitations of complex operating conditions. It should be a promising portable analytical tool for analysis of drug residues in the field.

Potency of teleophthalmology as a detection tool for diabetic retinopathy.

In China, the prevalence of diabetic retinopathy (DR) is increasing, so it is necessary to provide convenient and effective community outreach screening programs for DR, especially in rural and remote areas. The purpose of this study was to use the results of ophthalmologists as the gold standard to evaluate the accuracy of community general practitioners' judgement and grading of DR to find a feasible and convenient DR screening method to reduce the risk of visual impairment and blindness in known diabetes patients. Retinal images of 1646 diabetic patients who underwent DR screening through teleophthalmology at Nanchang First Hospital were collected for 30 months (January 2020 to June 2022). Retinal images were collected without medication for mydriasis, stored by community general practitioner, and diagnosed by both community general practitioner and ophthalmologist of our hospital through teleophthalmology. The grading of ophthalmologist was used as a reference or gold standard for comparison with that of community general practitioner. A total of 1646 patients and 3185 eyes were examined, including 2310 eyes with DR. The evaluation by the community general practitioner had a Kappa value of 0.578, sensitivity of 80.58%, specificity of 89.94%, and accuracy of 83.38%% in 2020; a Kappa value of 0.685, sensitivity of 95.43%, specificity of 78.55%, and accuracy of 90.77% in 2021; and a Kappa value of 0.744, sensitivity of 93.99%, specificity of 88.97%, and accuracy of 92.86% in 2022. Teleophthalmology helped with large-scale screening of DR and made it possible for community general practitioner to grade images with high accuracy after appropriate training. It is possible to solve the current shortage of eye care personnel, promote the early recognition of disease and reduce the impact of diabetes-associated blindness.