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Biomedical subjects

Peng Chen

Publications and source records attributed to Peng Chen.

At least 19 recordsLinked to original sources
PubMed2026

Genome editing generates high oleic soybean and eliminates beany flavors.

Soybeans serve as excellent sources of vegetable oil, protein, and other valuable nutrients for human consumption, materials for diverse industries, including the cosmetics and medical industries, and feedstocks for animals. Nevertheless, some people do not favor soy oil or other various food products derived from soybeans, due to inadequate levels of oleic acid in the oil and the presence of undesirable grassy and beany flavors associated with oxidation products of polyunsaturated fatty acids in the seeds. In this study, we developed soybean cultivars with very high levels of oleic acid in the seeds, and without grassy and beany flavors. We achieved this by using CRISPR-Cas-SF01 to edit genes in the elite cultivar Xudou 18 (XD18), targeting two microsomal Δ-12 fatty acid desaturase 2 (GmFAD2-1A and GmFAD2-1B) and three lipoxygenase (GmLOX1, GmLOX2, and GmLOX3) genes. Our findings showed that fad2-1a/b and fad2-1a/b/lox1/2/3 plants performed similarly to XD18 plants in the field, indicating no obvious growth penalties. Overall, this research has demonstrated that the development of soybean germplasms with high levels of oleic acid and without undesirable beany flavors through gene-editing of multiple relevant genes is effective, and this endeavor can contribute to the health of a broader global consumer population.

Gene Editing↗
PubMed2026

High-throughput identification of endogenous biomolecular condensates and phase-separating proteins.

Biomolecular condensates formed through liquid-liquid phase separation regulate cellular processes, and their dysregulation causes disease. Current methods for identifying endogenous phase-separating proteins have low throughput and cannot capture dynamic responses to stimuli. Here we present a protocol combining osmotic compression or transforming growth factor-β (TGF-β) treatment to induce condensation with sucrose density gradient centrifugation and quantitative mass spectrometry to enable systematic, high-throughput identification of endogenous condensates and phase-separating proteins. The method exploits the density changes that occur when phase-separating proteins undergo oligomerization during condensate formation. In H1975 cells, we identified over 1,500 phase-separating proteins under osmotic compression or TGF-β treatment; 538 of these candidates were not present in PhaSepDB, a database that compiles in vivo, in vitro and omics-derived proteins. The approach detects constitutive condensates and proteins that dynamically phase-separate in response to osmotic stress or TGF-β signaling. This protocol provides proteome-wide analysis of fractions of proteins having different densities and enables temporal resolution of phase-separation events. The procedure takes ~9 d and requires expertise in cell culture, biochemistry and mass spectrometry. This method enables systematic study of biomolecular condensates and disease-associated phase-separation mechanisms.

Phase Separation↗
PubMed2025

The Tartary Buckwheat FtMYB46-FtNRAMP3 Module Enhances Plant Lead and Cadmium Tolerance.

The presence of toxic heavy metals lead (Pb) and cadmium (Cd) in polluted soil damage crop production and consequently harms human and livestock health. Tartary buckwheat (Fagopyrum tataricum) is a potential model plant for heavy metal phytoremediation because of its valuable characteristics of high heavy metal tolerance and abundant biomass production. Here, we report that the Tartary buckwheat FtMYB46-FtNRAMP3 module enhances plant Pb and Cd tolerance. RNA sequencing analysis showed that Pb treatment specifically induced expression of FtNRAMP3, a member of the NRAMP (Natural Resistance-Associated Macrophage Protein) transporter gene family. Further cytological and biochemical analysis revealed that FtNRAMP3 was localised to the plasma membrane and significantly contributed to increased tolerance to Pb and Cd in yeast cells. Consistently, transgenic overexpression of FtNRAMP3 in Arabidopsis significantly increased plant tolerance to Pb and Cd applications, reducing Pb concentration but increasing Cd concentration in the overexpression transgenic plants. Subsequent yeast one-hybrid and electrophoretic mobility shift assays showed that the transcription factor FtMYB46 directly binds to the FtNRAMP3 promoter. Further, FtMYB46 promoted FtNRAMP3 expression and increased plant Pb and Cd tolerance. Overall, this study demonstrates the important role of the FtMYB46-FtNRAMP3 module and its potential value in the phytoremediation of Pb and Cd stress.

Cadmium↗
PubMed2006

Differential dependence on DNA ligase of type II restriction enzymes: a practical way toward ligase-free DNA automaton.

DNA computing study is a new paradigm in computer science and biological computing fields. As one of DNA computing approaches, DNA automaton is composed of the hardware, input DNA molecule and state transition molecules. By now restriction enzymes are key hardware for DNA computing automaton. It has been found that DNA computing efficiency may be independent on DNA ligases when type IIS restriction enzymes like FokI are used as hardware. In this study, we compared FokI with four other distinct enzymes HgaI, BsmFI, BbsI, and BseMII, and found their differential independence on T4 DNA ligase when performing automaton reactions. Since DNA automaton is a potential powerful tool to tackle gene relationship in genomic network scale, the feasible ligase-free DNA automaton may set an initial base to develop functional DNA automata for various DNA technology development and implications in genetics study in the near future.

Automation↗
PubMed2006

Monte Carlo simulations of cylinder-forming ABC triblock terpolymer thin films.

We systematically study the cylinder-forming ABC triblock terpolymer thin films using canonical ensemble Monte Carlo simulations. The simulated annealing procedure is applied to the self-assembling process. By judicious choice of the system dimensions, we elaborately investigate the effect of film thickness on the orientation of the cylinders. This confined triblock terpolymer system exhibits different phase behavior under the weak and strong surface fields. In addition, we also investigate the ensemble-averaged chain orientations and relative density profiles.

Journal Article↗
PubMed2006

Chiral layered zincophosphate [d-Co(en)3]Zn3(H0.5PO4)2(HPO4)2 assembled about d-Co(en)(3)3+ complex cations.

A new chiral layered zincophosphate [d-Co(en)3]Zn3(H(0.5)PO4)2(HPO4)2, designated ZnPO-CJ16, has been hydrothermally synthesized by using the optically pure chiral metal complex d-Co(en)3I3 as the template. It contains 4.6-net sheets which array in a helical fashion with an ABCDEF stacking sequence along the [001] direction. The chiral d-Co(en)3(3+) complex cations reside in the interlayer regions. Interestingly, there exist symmetrical O...H...O H-bonds between inorganic sheets, which results in a pseudo-three-dimensional open-framework structure stabilized by strong H-bonds. The crystal data are as follows: ZnPO-CJ16, [d-Co(en)3]Zn3(H(0.5)PO4)2(HPO4)2; M = 818.26; hexagonal; P6(5)22 (No. 179); a = 8.5832(12) A; c = 52.610(11) A; U = 3356.6(9) A(3); T = 293(2) K; Z = 6; R1 = 0.0415 (I > 2sigma(I)); wR2 = 0.1383 (all data); Flack parameter, 0.04(4).

Journal Article↗
PubMed2006

KO(t)Bu-promoted three-component coupling of aldehydes and alkynes: highly efficient synthesis of 1-en-4-yn-3-ols and 2-en-4-yn-1-ols.

A KO(t)Bu-promoted three-component coupling reaction of aldehydes and alkynes without a transition-metal catalyst was developed in which the sequential addition/isomerization/addition processes take place in one pot. This reaction could be developed into a straightforward and effective method for rapid access to stereodefined (E)-1-en-4-yn-3-ol and (Z)-2-en-4-yn-1-ol compounds.

Journal Article↗
PubMed2006

Syntheses, structures, ionic conductivities, and magnetic properties of three new transition-metal borophosphates Na5(H3O){M(II)3[B3O3(OH)]3(PO4)6}.2H2O (M(II) = Mn, Co, Ni).

Three new open-framework transition-metal borophosphates Na5(H3O){M(II)3[B3O3(OH)]3(PO4)6}.2H2O (M(II) = Mn, Co, Ni) (denoted as MBPO-CJ25) have been synthesized under mild hydrothermal conditions. Single-crystal X-ray diffraction analyses reveal that the three compounds possess isostructural three-dimensional (3D) open frameworks with one-dimensional 12-ring channels along the [001] direction. Notably, the structure can also be viewed as composed of metal phosphate layers [M(II)(PO4)2]4- with Kagomé topology, which are further connected by [B3O7(OH)] triborates, giving rise to a 3D open framework. The guest water molecules locate in the 12-ring channels. Partial Na+ ions reside in the 10-ring side pockets within the wall of the 12-ring channels, and the other Na+ ions and protonated water molecules locate in the 6-ring windows delimited by MO6 and PO4 polyhedra to compensate for the negative charges of the anionic framework. These compounds show a high thermal stability and are stable upon calcinations at ca. 500 degrees C. Ionic conductivities, due to the motion of Na+ ions, are measured for these three compounds. They have similar activation energies of 1.13-1.25 eV and conductivities of 2.7 x 10(-7)-9.9 x 10(-7) S cm(-1) at 300 degrees C. Magnetic measurements reveal that there are very weak antiferromagnetic interactions among the metal centers of the three compounds. Crystal data: MnBPO-CJ25, hexagonal, P6(3)/m (No. 176), a = 11.9683(5) A, c = 12.1303(6) A, and Z = 2; CoBPO-CJ25, hexagonal, P6(3)/m (No. 176), a = 11.7691(15) A, c = 12.112(2) A, and Z = 2; NiBPO-CJ25, hexagonal, P6(3)/m (No. 176), a = 11.7171(5) A, c = 12.0759(7) A, and Z = 2.

Journal Article↗
PubMed2006

Effect of surface field on the morphology of a symmetric diblock copolymer under cylindrical confinement.

We have used lattice Monte Carlo simulations to investigate the molecular assembly of symmetric diblock copolymer melts within cylindrical nanochannels. We studied the effect that the surface field has on the copolymer morphology in three cylinders having different diameters. Upon varying the strength of the surface field, we observed a variety of morphologies, including stacked-disk, single-helix, catenoid-cylinder, gyroidal, stacked-circle, and concentric cylindrical barrel structures. The results of these simulations should be helpful when designing polymeric nanomaterials confined in cylindrical nanochannels.

Journal Article↗
PubMed2006

Severe acute respiratory syndrome diagnostics using a coronavirus protein microarray.

To monitor severe acute respiratory syndrome (SARS) infection, a coronavirus protein microarray that harbors proteins from SARS coronavirus (SARS-CoV) and five additional coronaviruses was constructed. These microarrays were used to screen approximately 400 Canadian sera from the SARS outbreak, including samples from confirmed SARS-CoV cases, respiratory illness patients, and healthcare professionals. A computer algorithm that uses multiple classifiers to predict samples from SARS patients was developed and used to predict 206 sera from Chinese fever patients. The test assigned patients into two distinct groups: those with antibodies to SARS-CoV and those without. The microarray also identified patients with sera reactive against other coronavirus proteins. Our results correlated well with an indirect immunofluorescence test and demonstrated that viral infection can be monitored for many months after infection. We show that protein microarrays can serve as a rapid, sensitive, and simple tool for large-scale identification of viral-specific antibodies in sera.

Algorithms↗
PubMed2006

The clinical effect of herbal magnetic corsets on lumbar disc herniation.

OBJECTIVE: To determine the clinical effects of the treatment of lumbar disc herniation with herbal magnetic corsets. DESIGN: A randomized control trial. SETTING: The outpatient and inpatient departments of the Rehabilitation Center of the West China Hospital. PATIENTS: Sixty patients with clinically diagnosed lumbar disc herniation were included in the study. INTERVENTIONS: Both groups received lumbar traction, medium frequency electrotherapy and massage, whereas the experimental group wore herbal magnetic corsets in addition. MAIN OUTCOME MEASURES: Pain and lumbar function were assessed before treatment and at one week, two weeks and four weeks after intervention. RESULTS: Both groups reported improvements in pain and lumbar function after treatment (P 0.05 or P 0.001). However, the experimental group reported gradually increasing relief over time leading to a better curative effect than observed in the control group (P 0.05 for visual analogue scale or P 0.001 for lumbar function). CONCLUSION: Herbal magnetic corsets can facilitate the reduction of pain caused by lumbar disc herniation and can improve lumbar function. This is a safe and effective non-operative therapeutic option for treatment of lumbar disc herniation.

Adolescent↗
PubMed2006

[Association between the canine monoamine oxidase B (MAOB) gene polymorphisms and behavior of puppies in open-field test].

Excitability, activity and exploration behavior of puppies in a novel open-field were tested in a total of 204 two-month-old German shepherd dog, labrador retriever or English springer spaniel puppies. The polymorphisms of monoamine oxidase B gene (MAOB) were detected by PCR-RFLP. Statistics analysis indicated that genotype and allele frequencies of the polymorphisms were significantly different among three breeds (P < 0.01). With GLM analysis of SAS software, association analysis was conducted between MAOB gene polymorphisms and locomotion and vocalization behavior parameters in the open-field test. The results showed that MAOB gene polymorphisms had a significant effect on walking time, squares crossed, lying time, the times of standing up against walls(P < 0.01 or P < 0.05) and were associated with the times of posture change (P=0.064). Walking time and squares crossed were higher in TT genotype puppies than those in TC and CC puppies (P < 0.05) and the times of posture change and standing up against walls were also higher than those in CC (P < 0.05). In addition, lying time in CC genotype puppies were higher than that in TT (P < 0.05). MAOB had a positive effect on walking time, lying time, squares crossed, the times of posture change, the times of standing up against walls in the three dog breeds that was highly statistically significant (P < 0.01 or P < 0.05). Our results imply that MAOB gene significantly affects the excitability, activity and exploration behavior of puppies in open-field test and TT genotype has favorable effects in these behavior traits.

Animals↗
PubMed2006

An ultrastructural study on indirect trauma of dental pulp caused by maxillofacial impact injury in dogs.

BACKGROUND: Indirect injuries of adjacent tissues and organs usually accompany maxillofacial impact injuries. However, studies on indirect dental pulp injury are rare. This study was designed to determine the characteristics of indirect dental pulp injury caused by impact injury of mandible in dogs. METHODS: Eighteen dogs were divided equally into six groups with random allocation. Right mandible of each dog was impacted but teeth were not injured directly. Then, the animals were killed at appointed time points and ultrastructural changes in dental pulp of assigned teeth of each dog were investigated with transmission electron microscope. RESULTS: Dental pulp of the fourth premolar of right mandible was injured very severely, but irreversible necrosis did not occur in the end. Dental pulp of the second premolar of right mandible was injured less severely and reversibly. Dental pulp of the second premolar of left mandible was injured mildly and temporarily. CONCLUSION: In the indirect injury of dental pulp caused by maxillofacial impact injury, the injured area is relatively extensive. The effect of the trauma decreases progressively and sharply as the distance to the impact site increases. Ultrastructural changes in the damaged nerves take place early.

Animals↗
PubMed2006

[Structural characteristics of soil nematodes community under different land uses in Changchun City].

In this paper, an investigation on the species richness and abundance of soil nematodes in farmland, natural secondary forest, shelter forest and green space was made in Changchun City in July and September, 2003. Soil nematodes were extracted with Baermann extractor, and identified to the genus level with the aid of microscope. A total of 7273 soil nematode individuals were captured, and fell into 2 classes, 7 orders, 20 families, and 27 genera. Aphelenchus, Tylenchus and Pratylenchus were the dominant genera, which accounted for 61.58% of total individuals. Land use type had a significant effect on the community structure of soil nematodes, and aboveground litter removal and cultivation activity were the main factors affecting soil nematodes community structure. Above-ground litter removal considerably decreased soil nematodes individual density and community diversity, while cultivation activity changed the vertical distribution of soil nematodes individual density in the soil profile. Above-ground vegetation structure and landscape pattern appeared to have little effect on the ecological structure of soil nematodes community.

Animals↗
PubMed2005

Observation of individual microtubule motor steps in living cells with endocytosed quantum dots.

We report the observation of individual steps taken by motor proteins in living cells by following movements of endocytic vesicles that contain quantum dots (QDs) with a fast camera. The brightness and photostability of quantum dots allow us to record motor displacement traces with 300 micros time resolution and 1.5 nm spatial precision. We observed individual 8 nm steps in active transport toward both the microtubule plus- and minus-ends, the directions of kinesin and dynein movements, respectively. In addition, we clearly resolved abrupt 16 nm steps in the plus-end direction and often consecutive 16 nm and occasional 24 nm steps in minus-end directed movements. This work demonstrates the ability of the QD assay to probe the operation of motor proteins at the molecular level in living cells under physiological conditions.

Cell Line, Tumor↗
PubMed2005

Predicting protein interaction sites from residue spatial sequence profile and evolution rate.

This paper proposes a novel method that can predict protein interaction sites in heterocomplexes using residue spatial sequence profile and evolution rate approaches. The former represents the information of multiple sequence alignments while the latter corresponds to a residue's evolutionary conservation score based on a phylogenetic tree. Three predictors using a support vector machines algorithm are constructed to predict whether a surface residue is a part of a protein-protein interface. The efficiency and the effectiveness of our proposed approach is verified by its better prediction performance compared with other models. The study is based on a non-redundant data set of heterodimers consisting of 69 protein chains.

Algorithms↗
PubMed2005

Effect of Helicobacter pylori infection on gastric mucosal pathologic change and level of nitric oxide and nitric oxide synthase.

AIM: To investigate the level of nitric oxide (NO) and nitrous oxide synthase (NOS) enzyme and its effect on gastric mucosal pathologic change in patients infected with Helicobacter pylori (H pylori), and to study the pathogenic mechanism of H pylori. METHODS: The mucosal tissues of gastric antrum were taken by endoscopy, then their pathology, H pylori and anti-CagA-IgG were determined. Fifty H pylori positive cases and 35 H pylori negative cases were randomly chosen. Serum level of NO and NOS was detected. RESULTS: One hundred and seven cases (71.33%) were anti-CagA-IgG positive in 150 H pylori positive cases. The positive rate was higher especially in those with pre-neoplastic diseases, such as atrophy, intestinal metaplasia and dysplasia. The level of NO and NOS in positive group was higher than that in negative group, and apparently lower in active gastritis than in pre-neoplastic diseases such as atrophy, intestinal metaplasia and dysplasia. CONCLUSION: H pylori is closely related with chronic gastric diseases, and type I H pylori may be the real factor for H pylori-related gastric diseases. Infection with H pylori can induce elevation of NOS, which produces NO.

Chronic Disease↗