Activation of Actuating Hydrogels with WS2 Nanosheets for Biomimetic Cellular Structures and Steerable Prompt Deformation

Macroscopic soft actuation is intrinsic to living organisms in nature, including slow deformation (e.g., contraction, bending, twisting, and curling) of plants motivated by microscopic swelling and shrinking of cells, and rapid motion of animals (e.g., deformation of jellyfish) motivated by cooperative nanoscale movement of motor proteins. These actuation behaviors, with an exceptional combination of tunable speed and programmable deformation direction, inspire us to design artificial soft actuators for broad applications in artificial muscles, nanofabrication, chemical valves, microlenses, soft robotics, etc. However, so far artificial soft actuators have been typically produced on the basis of poly(N-isopropylacrylamide) (PNiPAM), whose deformation is motived by volumetric shrinkage and swelling in analogue to plant cells, and exhibits sluggish actuation kinetics. In this study, alginate-exfoliated WS₂ nanosheets were incorporated into ice-template-polymerized PNiPAM hydrogels with the cellular microstructures which mimic plant cells, yet the prompt steerable actuation of animals. Because of the nanosheet-reinforced pore walls formed in situ in freezing polymerization and reasonable hierarchical water channels, this cellular hybrid hydrogel achieves super deformation speed (on the order of magnitude of 10° s), controllable deformation direction, and high near-infrared light responsiveness, offering an unprecedented platform of artificial muscles for various soft robotics and devices (e.g., rotator, microvalve, aquatic swimmer, and water-lifting filter).

Biomimetic Hybridization of Kevlar into Silk Fibroin: Nanofibrous Strategy for Improved Mechanic Properties of Flexible Composites and Filtration Membranes

Silk, one of the strongest natural biopolymers, was hybridized with Kevlar, one of the strongest synthetic polymers, through a biomimetic nanofibrous strategy. Regenerated silk materials have outstanding properties in transparency, biocompatibility, biodegradability and sustainability, and promising applications as diverse as in pharmaceutics, electronics, photonic devices and membranes. To compete with super mechanic properties of their natural counterpart, regenerated silk materials have been hybridized with inorganic fillers such as graphene and carbon nanotubes, but frequently lose essential mechanic flexibility. Inspired by the nanofibrous strategy of natural biomaterials (e.g., silk fibers, hemp and byssal threads of mussels) for fantastic mechanic properties, Kevlar was integrated in regenerated silk materials by combining nanometric fibrillation with proper hydrothermal treatments. The resultant hybrid films showed an ultimate stress and Young's modulus two times as high as those of pure regenerated SF films. This is not only because of the reinforcing effect of Kevlar nanofibrils, but also because of the increasing content of silk β-sheets. When introducing Kevlar nanofibrils into the membranes of silk nanofibrils assembled by regenerated silk fibroin, the improved mechanic properties further enabled potential applications as pressure-driven nanofiltration membranes and flexible substrates of electronic devices.

A Genetic Variant Ameliorates β-Thalassemia Severity by Epigenetic-Mediated Elevation of Human Fetal Hemoglobin Expression

A delayed fetal-to-adult hemoglobin (Hb) switch ameliorates the severity of β-thalassemia and sickle cell disease. The molecular mechanism underlying the epigenetic dysregulation of the switch is unclear. To explore the potential cis-variants responsible for the Hb switching, we systematically analyzed an 80-kb region spanning the β-globin cluster using capture-based next-generation sequencing of 1142 Chinese β-thalassemia persons and identified 31 fetal hemoglobin (HbF)-associated haplotypes of the selected 28 tag regulatory single-nucleotide polymorphisms (rSNPs) in seven linkage disequilibrium (LD) blocks. A Ly1 antibody reactive (LYAR)-binding motif disruptive rSNP rs368698783 (G/A) from LD block 5 in the proximal promoter of hemoglobin subunit gamma 1 (HBG1) was found to be a significant predictor for β-thalassemia clinical severity by epigenetic-mediated variant-dependent HbF elevation. We found this rSNP accounted for 41.6% of β-hemoglobinopathy individuals as an ameliorating factor in a total of 2,738 individuals from southern China and Thailand. We uncovered that the minor allele of the rSNP triggers the attenuation of LYAR and two repressive epigenetic regulators DNA methyltransferase 3 alpha (DNMT3A) and protein arginine methyltransferase 5 (PRMT5) from the HBG promoters, mediating allele-biased γ-globin elevation by facilitating demethylation of HBG core promoter CpG sites in erythroid progenitor cells from β-thalassemia persons. The present study demonstrates that this common rSNP in the proximal ^Aγ-promoter is a major genetic modifier capable of ameliorating the severity of thalassemia major through the epigenetic-mediated regulation of the delayed fetal-to-adult Hb switch and provides potential targets for the treatment of β-hemoglobinopathy.

Effect of vitamin D on the learning and memory ability of FGR rat and NMDA receptor expression in hippocampus

The aim of this study is to investigate the effect of vitamin D (VD) on the learning and memory ability of fetal growth restriction (FGR) rat and the expression of NMDA receptor in hippocampus. The FGR models of rat were established through passive smoking, and divided into two groups randomly, i.e. the control group and the observation group. Rats were fed regular diet with the addition of VD in the observation group. The serum level of 25(OH)-D₃ was assayed in both groups of the rats at different time points using ELISA, and the learning and memory ability of rat aged 30 days were evaluated using Morris water maze and passive avoidance test. In addition, we also compared the brain weight of rats at different age and detected the mRNA expression of NRI subunit of NMDA receptor of hippocampus of rats aged 30 days using quantitative RT-PCR. After 7 days, the serum level of 25(OH)D₃ in rats of the observation group was significantly higher than that of the control group (P<0.05); during the Morris water maze, we found no significant difference in comparison of the latency between the two groups in the first 2 days (P>0.05), but from the 3rd day, the latency of the observation group was shorter than that in the control group (P<0.05); in the passive avoidance test, no significant difference was identified when comparing the electric shock times between the two groups in the first 2 days, but from the 3rd day, the electric shock times in the observation group were significantly lower than those in the control group (P<0.05); the brain weight of rats in the observation group on the 1st, 7th and 14th day were all lower than those in the control group (P<0.05), but the comparison of brain weight at 21st and 30th day showed no significant difference (P>0.05) between the two groups. We also found that the mRNA and protein expression of NRI subunit of NMDA receptor in hippocampus was significantly higher in the observation group than in the control group (P<0.05). VD can increase the learning and memory ability of FGR rats, significantly ameliorating the cognitive dysfunction of FGR rat and improving the learning and memory ability of rats, which may be related to the upregulation of NRI subunit of NMDA receptor.

Genetic and epigenetic regulation on the transcription of GABRB2: Genotype-dependent hydroxymethylation and methylation alterations in schizophrenia

To improve our understanding of the abnormalities and non-Mendelian inheritance characteristics of schizophrenia, this study examined DNA methylation (5mC) and hydroxymethylation (5hmC) in the schizophrenia-associated GABRB2 gene encoding the type A γ-aminobutyric acid receptor β₂ subunit. DNAs from the peripheral white blood cells of 279 schizophrenic patients and 256 controls from the Chinese Han population were examined to reveal that the GABRB2 promoter P1-5mC level which was correlated with olanzapine administration, P2-5mC/5hmC level, and Alu-5mC level which was correlated with administration of ziprasidone or oxcarbazepine, were increased in schizophrenic patients. Significant correlations of the promoter 5mC/5hmC levels with the genotypes of single nucleotide polymorphisms (SNPs) were observed with SNPs rs72815526 (C/A) and rs3811997 (C/T). In schizophrenics, the heterozygous genotypes of rs72815526 (C/A) were correlated with increased 5hmC levels whereas the heterozygous genotypes of rs3811997 (C/T) were correlated with decreased 5mC levels. Moreover, the GABRB2 promoter with rs3811997(C/T) minor allele T or the methylation-disrupted type AG at -254 and -231 CCGG sites was observed to enhance the promoter activity in the luciferase reporter-transfected human embryonic kidney 293 cells. An elevated GABRB2 mRNA transcriptional level in human neuroblastoma IMR32 cells were accompanied by the decreased promoter 5hmC/5mC levels induced by 5-azacytidine or by increased histone H4 acetylation levels of the Alu-Yi6 region induced by valproic acid. These results reveal alterations in GABRB2 genotype-dependent methylation and hydroxymethylation in schizophrenia, which yielded transcriptional and translational alterations in the cultured cells, and help elucidate the genetic-epigenetic interactions influencing schizophrenia.

Bioinspired Coupling of Inorganic Layered Nanomaterials with Marine Polysaccharides for Efficient Aqueous Exfoliation and Smart Actuating Hybrids

WS₂ and marine alginate are perfectly coupled to ensure scalable production of exfoliated WS₂ with unprecedented efficiency, further providing super mechanical properties and the photothermal effect to their composites. Combined with the water-intake and cation-binding capabilities of alginate, biomimetic soft devices are designed with stimuli-responsiveness and actuating properties, capable of serving as a photo-driven motor, a walking robot, and a gripper.

Influence of Na+ and Ca2+ on flame retardancy, thermal degradation, and pyrolysis behavior of cellulose fibers

Flame-retardant cellulose-Na and cellulose-Ca fibers were successfully synthesized by grafting Na⁺ and Ca²⁺ onto cellulose fibers, and confirmed by FTIR. The combustion behavior of the fibers was assessed by the limiting oxygen index (LOI) and cone calorimeter (CONE). The maximum LOI values of cellulose-Na and cellulose-Ca fibers were 31 and 30, which are higher than that (19) of cellulose fibers. The CONE results showed that the values of heat-release rate and total heat release for cellulose-Na and cellulose-Ca fibers were significantly lower than those for cellulose fibers. The thermogravimetric analysis (TG) and differential thermogravimetric analysis (DTG) curves in the continuous and trigger modes showed that the cellulose-Na and cellulose-Ca fibers generated more residues than cellulose fibers. Thermogravimetric analysis-gas chromatography-mass spectrometry was used to detect the characteristic gases produced in the pyrolysis of cellulose-Na and cellulose-Ca fibers.

[Clinical research of differences of volume of pharyngeal cavity between normal healthy subjects and patients with severe obstructive sleep apnea hypopnea syndrome]

Objective:To investigate the differences of volume of pharyngeal cavity between normal healthy subjects and patients with severe obstructive sleep apnea hypopnea syndrome(OSAHS)before and after surgery and its application value in assessment of surgical curative effect.Method:Forty-four healthy male adults were included in normal group.Thirty-eight patients with severe OSAHS diagnosed by polysomnography were included in experimental group(OSAHS group). Volume of pharyngeal cavity, oropharynx and laryngopharynx measured by acoustic pharyngealmetry and AHI, obstructive apnea frequency and the lowest oxygen saturation recorded by PSG monitor were all obtained in normal groups and experimental groups before and 3 months after the surgery. All the data are statistically analyzed. Result:Volume of pharyngeal cavity,AHI,obstructive apnea frequency and lowest oxygen saturation of patients in experimental group were all improved after surgery compared with pre-operation(P<0.01). Conclusion: The measurement of pharyngeal cavity volume is helpful to the quantitative analysis of upper airway structure and determine the stenosis location, it is also useful to guide surgery and evaluate the curative effect of the surgery.

High frequency of OTOF mutations in Chinese infants with congenital auditory neuropathy spectrum disorder

Auditory neuropathy spectrum disorder (ANSD) is one of the most common diseases leading to hearing and speech communication barriers in infants and young children. The OTOF gene is the first gene identified for autosomal recessive non-syndromic ANSD, and patients with OTOF mutations have shown marked improvement of auditory functions from the cochlear implantation, but the true involvement of OTOF mutations in Chinese ANSD patients is still unknown which precludes the effective management of this disease. Here, we investigated the contribution of OTOF mutations to congenital ANSD patients in China. In all, 37 infants and young Children with ANSD were screened for all the exons of OTOF gene, of them 34 patients had no neonatal risk factors who were considered as congenital ANSD. The clinical manifestation and audiometric features were also investigated and compared in patients with and without OTOF mutations. In all, 14 of these subjects were shown to carry two or three mutant alleles of OTOF with the high frequency of 41.2% in congenital ANSD patients. In total, 15 novel pathogenic mutations and 10 reported mutations were identified. Our results confirmed that mutations in OTOF gene were a major cause of congenital ANSD in China. Identification of OTOF mutations can facilitate diagnosis, clinical intervention and counseling for congenital ANSD.

[Association of single nucleotide polymorphisms in the promoter of GABAA receptor β2 subunit gene with schizophrenia]

OBJECTIVE

To investigate the genetic association between schizophrenia and the polymorphism of GABA(A) receptor β2 subunit (GABRB2) gene.

METHODS

A population association analysis was performed of 5 single nucleotide polymorphisms (SNPs) in the proximal promoter of GABRB2 gene by PCR and sequencing of the genomic DNA in a cohort of 172 schizophrenics and 167 controls of Chinese Han nationality.

RESULTS

One out of the 5 SNPs, namely rs3811996, was found to be significantly associated with schizophrenia especially in the male cohorts, where the heterozygous genotypes (A/G) and minor allele G displayed lower frequencies in case group than in the controls.

CONCLUSION

We found a new risk, SNP rs3811996, for paranoia schizophrenia, which further supports the importance of genetic variations of GABRB2 in the etiology of schizophrenia.

Co3O4nanoparticle embedded carbonaceous fibres: a nanoconfinement effect on enhanced lithium-ion storage

Nanoconfined Co₃O₄/carbon fibres were developed by pyrolysis of Co²⁺coordinated regenerated cellulose fibres, which may pave a new way for the scalable synthesis of anode materials for Li ion batteries.

Connexin26 (GJB2) deficiency reduces active cochlear amplification leading to late-onset hearing loss

Connexin26 (Cx26, GJB2) mutations account for >50% of nonsyndromic hearing loss. The deafness is not always congenital. A large group of these patients (∼30%) demonstrate a late-onset hearing loss, starting in childhood. They have normal hearing early in life and are therefore good candidates for applying protective and therapeutic interventions. However, the underlying deafness mechanism is unclear. In this study, we used a time-controlled, inducible gene knockout technique to knockout Cx26 expression in the cochlea after birth. We found that deletion of Cx26 after postnatal day 5 (P5) in mice could lead to late-onset hearing loss. Similar to clinical observations, the mice demonstrated progressive, mild to moderate hearing loss. The hearing loss initiated at high frequencies and then extended to the middle- and low-frequency range. The cochlea showed normal development and had no apparent hair cell loss. However, distortion product otoacoustic emission (DPOAE) was reduced. The reduction was also progressive and large at high-frequencies. Consistent with DPOAE reduction, we found that outer hair cell electromotility-associated nonlinear capacitance was shifted to the right and the slope of voltage dependence was reduced. The endocochlear potential was reduced in Cx26 conditional knockout (cKO) mice but the reduction was not associated with progressive hearing loss. These data suggest that Cx26 deficiency may impair active cochlear amplification leading to late-onset hearing loss. Our study also helps develop newer protective and therapeutic interventions to this common nonsyndromic hearing loss.

Edaravone protects endotoxin-induced liver injury by inhibiting apoptosis and reducing proinflammatory cytokines

Studies have shown that edaravone may prevent liver injury. This study aimed to investigate the effects of edaravone on the liver injury induced by D-galactosamine (GalN) and lipopolysaccharide (LPS) in female BALB/c mice. Edaravone was injected into mice 30 min before and 4 h after GalN/LPS injection. The survival rate was determined within the first 24 h. Animals were killed 8 h after GalN/LPS injection, and liver injury was biochemically and histologically assessed. Hepatocyte apoptosis was measured by TUNEL staining; proinflammatory cytokines [tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6)] in the liver were assayed by ELISA; expression of caspase-8 and caspase-3 proteins was detected by Western blot assay; and caspase-3 activity was also determined. Results showed that GalN/LPS induced marked elevations in serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Edaravone significantly inhibited elevation of serum AST and ALT, accompanied by an improvement in histological findings. Edaravone lowered the levels of TNF-α and IL-6 and reduced the number of TUNEL-positive cells. In addition, 24 h after edaravone treatment, caspase-3 activity and mortality were reduced. Edaravone may effectively ameliorate GalN/LPS-induced liver injury in mice by reducing proinflammatory cytokines and inhibiting apoptosis.

Genetic variants in microRNA target sites of 37 selected cancer-related genes and the risk of cervical cancer

Objectives

Single nucleotide polymorphisms (SNPs) in putative microRNA binding sites (miRSNPs) modulate cancer susceptibility via affecting miRNA binding. Here, we sought to investigate the association between miRSNPs and cervical cancer risk.

Methods

We first genotyped 41 miRSNPs of 37 cancer-related genes in 338 patients and 334 controls (Study 1), and replicated the significant associations in 502 patients and 600 controls (Study 2). We tested the effects of miRSNPs on microRNA-mRNA interaction by luciferase reporter assay.

Results

Five SNPs displayed notable association with cervical cancer risk in Study 1. Only IL-16 rs1131445 maintained a significant association with cervical cancer (CT/CC vs. TT, adjusted OR = 1.51, P = 0.001) in Study 2. This association was more evident in the combined data of two studies (adjusted OR = 1.49, P = 0.00007). We also found that miR-135b mimics interacted with IL-16 3′-UTR to reduce gene expression and that the rs1131445 T to C substitution within the putative binding site impaired the interaction of miR-135b with IL-16 3′-UTR. An ELISA indicated that the serum IL-16 of patients with cervical cancer was elevated (vs. controls, P = 0.001) and correlated with the rs1131445 genotype. Patients who carried the rs1131445 C allele had higher serum IL-16 than non-carriers (P<0.001).

Conclusions

These results support our hypothesis that miRSNPs constitute a susceptibility factor for cervical cancers. rs1131445 affects IL-16 expression by interfering with the suppressive function of miR135b and this variant is significantly associated with cervical cancer risk.

High temperature requirement A1 in placental tissues and serum from pre-eclamptic pregnancies with or without fetal growth restriction

INTRODUCTION

Pre-eclampsia (PE) is the most serious syndrome of human pregnancy and it is potentially life-threatening for both mother and fetus. The aim of the study was to identify the role of high temperature requirement A1 (HtrA1) in pre-eclampsia.

MATERIAL AND METHODS

One hundred consecutive pregnancies complicated by PE and 100 normal controls were included in our study. The changes in serum HtrA1 and fetal growth restriction were recorded. The placentae after delivery was also obtained for laboratory analyses.

RESULTS

High temperature requirement A1 expressed positively in all placenta tissues, but showed higher expression from control, PE with AGA (pre-eclamptic pregnancies with appropriate-for-gestational-age newborns) to PE with fetal growth restriction (FGR) groups. Early-onset PE happened more frequently while in PE with AGA, late-onset PE was more common. Additionally, we found that only during ∼28-32 gestational weeks, sera HtrA1 level of PE with AGA and PE with FGR was increased significantly compared with the control group (p < 0.05). In contrast, there was no significant difference between groups in other gestational ages in the third trimester (p > 0.05).

CONCLUSIONS

HtrA1 could potentially affect trophoblast migration and invasion during placentation, resulting in the shallow invasion noted in pre-eclampsia. HtrA1 may play an important role in the etiology and severity of PE and FGR. But the actual mechanism still needs deep research.

Changes in the level of serum high-temperature requirement A1 (HtrA1) during pregnancy and its relationship to preeclampsia

OBJECTIVE

To investigate the expression and changes of high-temperature requirement A1 (HtrA1) during pregnancy and the use of this value in predicting preeclampsia.

METHOD

Serum samples were collected from pregnant mothers at different gestational weeks, and double-antibody sandwich enzyme-linked immunosorbent assay was employed to describe the changes in HtrA1 in serum during pregnancy.

RESULTS

(i) In Xi'an area of China, the incidence of preeclampsia was 4.95%, including 0.85% of early-onset type and 4.10% of late-onset type; (ii) the HtrA1 showed a lognormal distribution during pregnancy in the maternal serum, with the peak at 17-20 weeks of pregnancy; (iii) the HtrA1 levels in preeclampsia mothers peaked at 13-16 weeks of pregnancy, followed by acute decline until 21-24 weeks, then remained stable; (iv) the HtrA1 levels in preeclampsia mothers were higher than the control group in 13-16 weeks and lower than that in 21-24 weeks (p < 0.05); (v) the criteria using lgHtrA1 level at 1.684 during 13-16 weeks of pregnancy could predict hypertension disorders complicating pregnancy (HDCP) with sensitivity of 62.1% and specificity of 53.7%. This could be improved to 85 and 83%, respectively, when combined with body mass index as well as education background of the mother.

CONCLUSION

(i) HtrA1 showed lognormal distribution during pregnancy for all populations; (ii) HtrA1 level peaked at 17-20 weeks in normal group of pregnant mothers, and the increase of HtrA1 level in 13-16 weeks could predict the risk of preeclampsia; (iii) the risk calculation formula for preeclampsia: p (%) = eY/(1 + eY) (Y = -15.87 + 3.706 × lgHtrA1 + 0.134 × mean arterial pressure (MAP) - 1.4 × education level code); e = 2.718.

Correlation between P53 expression and malignant risk of gastrointestinal stromal tumors: evidence from 9 studies

PURPOSE

The published data about p53 expression and its potential value in malignant risk of Gastrointestinal Stromal Tumors patients seemed inconclusive. To derive a more precise estimation of the relationship between p53 and Malignant risk of GIST, a meta-analysis was performed.

MATERIALS AND METHODS

Studies have been identified by searching PubMed and Embase. Inclusive criteria were GIST patients, evaluation of p53 expression and malignant risk. The odds ratio (OR) for positive rate of p53 in NIH very low risk group vs. NIH low risk group, the odds ratio (OR) for positive rate of p53 in NIH low risk group vs. NIH Intermediate risk group and the odds ratio (OR) for positive rate of p53 in NIH Intermediate group vs. NIH high risk group were calculated with 95% confidence interval (CI) for each study as an estimation of potential value of p53 in malignant risk of GIST.

RESULTS

A total of 9 studies including 768 patients were involved in this meta-analysis. The meta-analysis of positive rate of p53 in NIH VL group vs. NIH L group did not attain significant difference (OR 0.38 95% CI, 0.11-1.28; P = 0.12 P(heterogeneity) = 0.51). However the overall OR for positive rate of p53 in NIH L group vs. NIH I group revealed that significantly elevated risks of positive p53 in NIH I group were achieved (OR 0.44 95% CI, 0.24-0.82; P = 0.009 P(heterogeneity) = 0.32). The overall OR for NIH I group vs. NIH H group was 0.62 (95% CI, 0.37-1.02; P = 0.06 P(heterogeneity) = 0.25).

CONCLUSION

The results indicate p53 overexpression correlate with the malignant risk increasing of GIST and have a primary and closest relationship within the NIH I risk group of GIST.

Coding regions of INHBA, SFRP4 and HOXA10 are not implicated in familial endometriosis linked to chromosome 7p13-15

Endometriosis is a common, chronic gynaecological disease affecting up to 10% of women in their reproductive years. Its aetiology still remains unclear, but evidence indicates genetic factors play a role. We previously identified a region of significant linkage on chromosome 7 in 52 families comprising at least three affected women, stretching ∼6.4 Mb. We screened coding regions and parts of the regulatory regions of three candidate genes with a known role in endometrial development and function-INHBA, SFRP4 and HOXA10-located under or very near the linkage peak, for potential causal mutations using Sanger sequencing. Sequencing was conducted in 47 cases from the 15 families contributing most to the linkage signal (Z(mean) ≥ 1). Minor allele frequencies (MAFs) of observed variants were compared with MAFs from two publicly available reference populations of European ancestry: 60 individuals in HapMap and 150 individuals in the 1000 Genomes Project. A total of 11 variants were found, 5 (45%) of which were common (MAF > 0.05) among the 15 case families and the reference populations (P-values for MAF difference: 0.88-1.00). The remaining six were rare and unlikely to be individually or cumulatively responsible for the linkage signal. The results indicate that the coding regions of these three genes do not harbour mutations responsible for linkage to endometriosis in these families.

[Effect of organs biomass by drought stress on the leaf growing stage of Angelica dahurica var. formosana]

OBJECTIVE

To study the effect of natural drought stress conditions on Angelica dahurica var. formnosana vegetative organs biomass accumulation and allocation in leaf growing season. To discuss the changing law of Angelica dahurica var. formosana vegetative organs biomass in different drought stress conditions.

METHODS

Measured Angelica dahurica var. formnosana leaf and leafstalk's biomass, all aboveground biomass and the ratio of root biomass, leaf biomass, root/shoot ratio etc. in the growing season under the natural drought stress condition.

RESULTS

Slight drought stress condition was good for organs' biomass accumulation, medium and serious drought stress conditions were bad for organs biomass accumulation. Slight and medium drought stress conditions were good for biomass transit to the root in the leaf growing season and serious drought stress condition was not good for that.

CONCLUSION

Suitable drought stress can improve the root biomass ratio in Angelica dahurica var. formosana leaf growing season and get a better yield.

A distinct spectrum of SLC26A4 mutations in patients with enlarged vestibular aqueduct in China

There is a worldwide interest in studying SLC26A4 mutations that are responsible for enlarged vestibular aqueduct (EVA) in different ethnic background and populations. The spectrum of SLC26A4 mutations in Chinese population is yet to be fully characterized. In this study, all the 21 exons of SLC26A4 were screened in 107 Chinese patients with hearing loss associated with EVA or both EVA and Mondini dysplasia (MD), taken from six multiplex and 95 simplex families. The two types of control populations consisted of 84 normal-hearing subjects and 46 sensorineural hearing loss subjects without inner ear malformations. Biallelic mutations were found in 12 patients from multiplex families and 84 patients (88.4%) from the simplex families. In addition, monoallelic variant was detected in nine patients in the remaining 11 simplex families. Overall, up to 97.9% patients were found having at least one possible pathogenic variant in SLC26A4, with most having biallelic variants consistent with recessive inheritance of this disorder. A total of 40 mutations including 25 novel mutations were identified in the Chinese patients but were not detected in all the controls except for one normal subject. For the Chinese mutation spectrum of SLC26A4 gene, IVS 7-2A>G mutation was the most common form accounting for 57.63% (102/177) of all the mutant alleles.

A review of microwave-assisted polymer chemistry (MAPC)

As a relatively new source of processing energy, microwave energy offers many compelling advantages in materials processing over conventional heat sources. These advantages include greater flexibility, greater speed and energy savings, improved product quality and properties, and synthesis of new materials that cannot be produced by other heating methods. Studies of microwave processing of polymeric materials in the early 1960s led to a successful industrial application in the rubber industry. Since the mid-1980's, there has been a great deal of interest in microwave processing of polymeric materials worldwide. The discipline can be categorized in two major fields: microwave-assisted polymer physics (MAPP) and microwave assisted polymer chemistry (MAPC). This paper offers an overview of the state-of-the-art research on the field of MAPC, including polymer processing (curing of thermosets, processing of thermoplastics, and joining), polymer synthesis, plasma modification of polymer surfaces, plasma polymerization, polymer degradation, and production of nanomaterials. Most of these studies have focused on laboratory-scale, exploratory efforts. Challenges and possible future directions for the commercialization of microwave processing technologies are discussed.

[Influence of planting density and precipitation on N2O emission from a winter wheat field]

To investigate the impact of plant density on N2O emission from winter wheat field and the cause of seasonal variation in the emission, field experiment with four planting rates of 0, 90, 180 and 270 kg/ha was conducted at the Jiangning County near Nanjing during 1999-2000 winter wheat growing season. Data of the field measurements indicated that the N2O emission rates during the season from planting to overwintering were not influenced by the plant density, while the emission was positively correlated with the planting density during the season from turning green to maturity. The emissions from the field plots with planting rates of 0 and 90 kg/ha were not found to be significantly different. A further analysis suggested that the seasonal variation of N2O emission be mainly influenced by precipitation, which could be quantitatively described by an exponential function of a weighted average precipitation of 6-day period before measurement.

P[Switch], a system for spatial and temporal control of gene expression in Drosophila melanogaster

We have developed a method for turning on and off the expression of transgenes within Drosophila in both time and space. Two different enhancer detector elements carrying an RU486-inducible form of the yeast transcription factor GAL4 were constructed and used to generate enhancer detector lines. These lines were screened for RU486-inducible reporter gene expression in the adult head. We identified lines that exhibit inducible expression in many cell and tissue types, verifying that the elements respond to nearby enhancers. No expression was detected in the absence of the ligand. The P[Switch1] element responded to genomic enhancers less efficiently than P[Switch2] but produced more specific patterns of expression. Two P[Switch] lines were used to ablate fat body tissue in adult females through the induced expression of diphtheria toxin. These females were sterile, which correlates with fat body loss, and they died prematurely.

[Association of human leukocyte antigen-DQA1 with endometriosis of women in southern China]

OBJECTIVE

To study the genetic susceptibility in patients with endometriosis by genotyping their human leukocyte antigen-DQA1 (HLA-DQA1) alleles.

METHODS

The allelic types of HLA-DQA1 were detected by polymerase chain reaction single specific primers (PCR-SSP) technique in 51 patients with endometriosis proven by laparoscopy or histological examination, and 44 control women who had laparoscopic sterilization and without endometriosis.

RESULTS

The frequency of HLA-DQA * 0401 allele (12%) in patients with endometriosis group was markedly higher than that in the control group (0%) (P = 0.019). Contrarily, the frequency of HLA-DQA1 * 0301 allele (39%) in control group was higher than that in endometriosis group (14%) (P = 0.005, odds ratio = 0.253).

CONCLUSION

Our result indicated that HLA-DQA1 * 0401 may be a susceptible gene in correlation with endometriosis, whereas HLA-DQA1 * 0301 may be a protective gene against endometriosis.

Metabolic fate of gallic acid orally administered to rats

The metabolic behavior of orally administered gallic acid was investigated by HPLC and 4-O-methyl gallic acid was found to be the main metabolite in rat peripheral blood and urine. After oral administration of gallic acid, maximum concentration in portal vein and inferior vena cava occurred at 15 and 30 min, respectively. In portal vein, gallic acid was preferentially detected relative to 4-O-methyl gallic acid, whereas gallic acid and 4-0-methyl gallic acid were equally detected in inferior vena cava. On the other hand, 4-O-methyl gallic acid but not gallic acid was found in liver. The contents of gallic acid and 4-O-methyl gallic acid in urine were nearly 100 times higher than those in blood. The ratio of 4-O-methyl gallic acid to total gallic acid metabolites in urine was from 0.55 to 0.76, indicating that a considerable amount of gallic acid was excreted without being metabolized. In this study we found that gallic acid administered orally existed in the blood for 6 h at most, and more than half was metabolized to 4-O-methyl gallic acid, followed by excretion into urine.

Insulin-like compounds related to the amphioxus insulin-like peptide

Three insulin-like compounds consisting of two disulfide-linked polypeptide chains have been synthesized. The A-chains of these compounds correspond either to the A- or to the A + D-domain of the putative amphioxus insulin-like peptide (amphioxus ILP), and their B-chains correspond either to the B-chain of insulin or to a slightly modified (i.e., [1-Thr]) B-domain of amphioxus ILP. The biological potency of these compounds was evaluated in mammalian cells or cell fractions containing either human or rat insulin receptors or human or mouse insulin-like growth factor I (IGF-I) receptors, with respect to binding affinity, insulin-like metabolic activity (lipogenesis), and growth factor activity (mitogenesis). Amphioxus ILP A/bovine insulin B and amphioxus ILP A + D/bovine insulin B exhibited potencies ranging from 2.0 to 9.8% relative to natural insulin, and both compounds were full agonists in lipogenesis assays, stimulating lipogenesis to the same maximal extent as seen with natural insulin. Amphioxus ILP A/amphioxus ILP [1-Thr]B stimulated lipogenesis with a potency of 0.01% relative to natural insulin. We consider this compound also likely to be a full agonist. In assays measuring binding to IGF-I receptors and stimulation of mitogenesis, these compounds displayed some activity although the activity was too low for exact quantification. These results suggest that amphioxus ILP has retained an overall structural similarity to mammalian insulin and IGF-I but has also accumulated substantial mutations which markedly reduce its ability to bind and activate their cognate receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

The A14 position of insulin tolerates considerable structural alterations with modest effects on the biological behavior of the hormone

As part of our aim to investigate the contribution of the tyrosine residue found in the 14 position of the A-chain to the biological activity of insulin, we have synthesized six insulin analogues in which the A14 Tyr has been substituted by a variety of amino acid residues. We have selected three hydrophilic and charged residues--glutamic acid, histidine, and lysine--as well as three hydrophobic residues--cycloleucine, cyclohexylalanine, and naphthyl-(1)-alanine--to replace the A14 Tyr. All six analogues exhibit full agonist activity, reaching the same maximum stimulation of lipogenesis as is achieved with porcine insulin. The potency for five of the six analogues, [A14 Glu]-, [A14 His]-, [A14 Lys]-, [A14 cycloleucine]-, and [A14 naphthyl-(1)-alanine]-insulins in receptor binding assays ranges from 40-71% and in stimulation of lipogenesis ranges from 35-120% relative to porcine insulin. In contrast, the potency of the sixth analogue, [A14 cyclohexylalanine]insulin, in both types of assays is less than 1% of the natural hormone. The retention time on reversed-phase high-performance liquid chromatography for the first five analogues is similar to that of bovine insulin, whereas for the sixth analogue, [A14 cyclohexylalanine]insulin, it is approximately 11 min longer than that of the natural hormone. This suggests a profound change in conformation of the latter analogue. Apparently, the A14 position of insulin can tolerate a wide latitude of structural alterations without substantial decrease in potency. This suggests that the A14 position does not participate directly in insulin receptor interaction. Only when a substitution which has the potential to disrupt the conformation of the molecule is made at this position, is the affinity for the receptor, and hence the biological potency, greatly reduced.

Superactive insulins

The substitution of aspartic acid for the naturally-occurring histidine residue in position B10 in human insulin results in an insulin analogue which displays an in vitro potency 4- to 5-fold greater than the parent compound. This substitution has been introduced into six insulin analogues which, before modification, display potencies ranging from less than 0.01-fold to 3-fold relative to natural insulin. In each case, the resulting aspartic acid-substituted analogue is substantially more potent than the parent compound. Thus, it is now possible to prepare "tailor-made" insulins with enhanced potency.

An insulin-like hybrid consisting of a modified A-domain of human insulin-like growth factor I and the B-chain of insulin

We have synthesized an insulin-like compound, consisting of the B-chain of bovine insulin and an A-chain corresponding to the A-domain of human insulin-like growth factor-I (IGF-I), in which the isoleucine residue normally present in position 2 of the A-domain of IGF-I has been replaced with glycine. Biological evaluation of the compound indicated that its insulin-like activity (insulin receptor-binding and stimulation of lipogenesis) was 0.2%, and its growth-factor activity (stimulation of thymidine incorporation) was less than 1%, both relative to natural insulin. We conclude that interactions between IleA2 and TyrA19, which are crucial to high biological activity in insulin, are also present in IGF-I, and are equally critical for its biological activity.

Determinants of growth-promoting activity reside in the A-domain of insulin-like growth factor I

A two-chain, disulfide linked, insulin-like compound embodying the A-domain of insulin-like growth factor I (IGF-I) and the B-chain of insulin has been synthesized and characterized with respect to insulin-like biological activity and growth-promoting potency. The compound displays a potency of ca. 41% relative to insulin in assays for insulin-like activity (e.g., lipogenesis) but significantly higher activity than insulin, ca. 730% relative to insulin, in growth factor assays (e.g., thymidine incorporation). The compound is, however, a less potent growth factor than IGF-I itself, ca. 26.5% relative to IGF-I, and is not recognized by IGF carrier proteins. We conclude that structural features contained in the A-domain of IGF-I are primarily responsible for the growth-promoting ability displayed by IGF-I, while features in the B-domain are responsible for recognition by IGF carrier proteins.