Mutation in a non-force-bearing region of protein L influences force-dependent unfolding behavior

Single-molecule magnetic tweezers(MTs) have revealed multiple transition barriers along the unfolding pathway of several two-state proteins, such as GB1 and Csp. In this study, we utilized MTs to measure the force-dependent folding and unfolding rates of both protein L(PLWT) and its Y47W mutant(PLY47W) where the mutation point is not at the force-bearing β-strands. The measurements were conducted within a force range of 3–120 pN. Notably, the unfolding rates of both PLWT and PWY47W exhibit distinct force sensitivities below 50 pN and above 60 pN, implying a two-barrier free energy landscape. Both PLWT and PLY47W share the same force-dependent folding rate and the same transition barriers,but the unfolding rate of PLY47W is faster than that of PLWT. Our finding demonstrates that the residue outside of the force-bearing region will also affect the force-induced unfolding dynamics.

Selection of New Energy Development Models in Rural Jilin Province under Different Situations

Jilin Province’s vast rural areas are endowed with abundant new energy resources,which provide a fundamental condition for the development of new energy in rural Jilin.This paper will explore the various possibilities of new energy development in rural Jilin under the background of grid infrastructure construction,the deepening of electricity market reform,the modernization of agriculture and rural areas,and the transformation of energy.It will draw conclusions on the reasonable development models of new energy in rural Jilin under different scenarios,providing a reference for the development of new energy in rural Jilin and rural revitalization.

PKM2-mediated neuronal hyperglycolysis enhances the risk of Parkinson's disease in diabetic rats

Epidemiological and animal studies indicate that pre-existing diabetes increases the risk of Parkinson's disease(PD).However,the mechanisms underlying this association remain unclear.In the present study,we found that high glucose(HG)levels in the cerebrospinal fluid(CSF)of diabetic rats might enhance the effect of a subthreshold dose of the neurotoxin 6-hydroxydopamine(6-OHDA)on the development of motor disorders,and the damage to the nigrostriatal dopaminergic neuronal pathway.In vitro,HG promoted the 6-OHDA-induced apoptosis in PC12 cells differentiated to neurons with nerve growth factor(NGF)(NGF-PC12).Metabolomics showed that HG promoted hyperglycolysis in neurons and impaired tricarboxylic acid cycle(TCA cycle)activity,which was closely related to abnormal mitochondrial fusion,thus resulting in mitochondrial loss.Interestingly,HG-induced upregulation of pyruvate kinase M2(PKM2)combined with 6-OHDA exposure not only mediated glycolysis but also promoted abnormal mitochondrial fusion by upregulating the expression of MFN2 in NGF-PC12 cells.In addition,we found that PKM2 knockdown rescued the abnormal mitochondrial fusion and cell apoptosis induced by HGþ6-OHDA.Furthermore,we found that shikonin(SK),an inhibitor of PKM2,restored the mitochondrial number,promoted TCA cycle activity,reversed hyperglycolysis,enhanced the tolerance of cultured neurons to 6-OHDA,and reduced the risk of PD in diabetic rats.Overall,our results indicate that diabetes promotes hyperglycolysis and abnormal mitochondrial fusion in neurons through the upregulation of PKM2,leading to an increase in the vulnerability of dopaminergic neurons to 6-OHDA.Thus,the inhibition of PKM2 and restoration of mitochondrial metabolic homeostasis/pathways may prevent the occurrence and development of diabetic PD.

OsTHA8 encodes a pentatricopeptide repeat protein required for RNA editing and splicing during rice chloroplast development

In higher plants, the chloroplast is the most important organelle for photosynthesis and for numerous essential metabolic processes in the cell. Although many genes involved in chloroplast development have been identified, the mechanisms underlying such development are not fully understood. In this study, a rice(Oryza sativa) mutant exhibiting pale green color and seedling lethality was isolated from a mutant library. The mutated gene was identified as an ortholog of THA8(thylakoid assembly 8) in Arabidopsis and maize. This gene is designated as OsTHA8 hereafter. OsTHA8 showed a typical pentatricopeptide repeat(PPR) characteristic of only four PPR motifs. Inactivation of OsTHA8 led to a deficiency in chloroplast development in the rice seedling stage. OsTHA8 was expressed mainly in young leaves and leaf sheaths.The OsTHA8 protein was localized to the chloroplast. Loss of function of OsTHA8 weakened the editing efficiency of ndhB-611/737 and rps8-182 transcripts under normal conditions. Y2H and BiFC indicated that OsTHA8 facilitates RNA editing by forming an editosome with multiple organellar RNA editing factor(OsMORF8) and thioredoxin z(OsTRXz), which function in RNA editing in rice chloroplasts. Defective OsTHA8 impaired chloroplast ribosome assembly and resulted in reduced expression of PEP-dependent genes and photosynthesis-related genes. Abnormal splicing of the chloroplast gene ycf3 was detected in ostha8. These findings reveal a synergistic regulatory mechanism of chloroplast biogenesis mediated by RNA, broaden the function of the PPR family, and shed light on the RNA editing complex in rice.

Function identification of miR159a,a positive regulator during poplar resistance to drought stress

Drought seriously affects the growth and development of plants.MiR159 is a highly conserved and abundant microRNA family that plays a crucial role in plant growth and stress responses.However,studies of its function in woody plants are still lacking.Here,the expression of miR159a was significantly upregulated after drought treatment in poplar,and the overexpression of miR159a(OX159a)significantly reduced the open area of the stomata and improved water-use efficiency in poplar.After drought treatment,OX159a lines had better scavenging ability of reactive oxygen species and damage of the membrane system was less than that in wild-type lines.MYB was the target gene of miR159a,as verified by psRNATarget prediction,RT-qPCR,degradome sequencing,and 5′rapid amplification of cDNA ends(5′RACE).Additionally,miR159a-short tandem target mimic suppression(STTM)poplar lines showed increased sensitivity to drought stress.Transcriptomic analysis comparing OX159a lines with wild-type lines revealed upregulation of a series of genes related to response to water deprivation and metabolite synthesis.Moreover,drought-responsive miR172d and miR398 were significantly upregulated and downregulated respectively in OX159a lines.This investigation demonstrated that miR159a played a key role in the tolerance of poplar to drought by reducing stomata open area,increasing the number and total area of xylem vessels,and enhancing water-use efficiency,and provided new insights into the role of plant miR159a and crucial candidate genes for the molecular breeding of trees with tolerance to drought stress.

Research on the Four Collaborative Innovation Mechanisms of Industry-education Integration Based on the Concept of Community

The concept of community is of great significance in guiding the innovation of the mechanism of industry-education integration,which can promote the integration of industry-education integration from"integration"to real"integration".We summarize the current situation of the development of industry-teaching integration mode through research,point out the"four deviations"in the development of industry-teaching integration,analyze the causes of deviations,and put forward the research strategy of"four synergistic"innovation mechanism for industry-teaching integration based on the concept of community,i.e.,synergistic development of community planning It proposes the research strategy of"four synergies"innovation mechanism based on the concept of community,namely the synergy of community planning and development,the synergy of community governance concept,the synergy of community multi-party educating mechanism,and the synergy of community fusion effect system,so as to establish collaborative ties,build a new form of cooperation concepts,safeguard the docking of talent supply and demand,and enhance the effect of integration of industry and education.

Differentiation of fetal pancreatic stem cells into neuron-like and islet-like cells in vitro

Pancreatic stem cells were isolated and cultured from aborted human fetal pancreases of gestational age 14-20 weeks. They were seeded at a density of 1 × 104 in serum-free media for differentiation into neuron-like cells, expressing β-tubulin III and glial fibrillary acidic protein. These neuron-like cells displayed a synapse-like morphology and appeared to form a neuronal network. Pancreatic stem cells were also seeded at a density of 1 × 105 for differentiation into islet-like cells, expressing insulin and glucagon, with an islet-like morphology. These cells had glucose-stimulated secretion of human insulin and C-peptide. Results suggest that pancreatic stem cells can be differentiated into neuron-like and islet-like cells.

ALM1, encoding a Fe-superoxide dismutase, is critical for rice chloroplast biogenesis and drought stress response

Chloroplasts are the center of plant life activities including photosynthesis,growth and development,and abiotic stress response.Chloroplast development and biogenesis in rice have been studied in detail,but how does abiotic stress affect chloroplasts is less studied.We obtained an albino mutant,alm1,whose chlorophyll content was greatly decreased.Transmission electron microscopy showed that chloroplast development in alm1 was blocked,especially in thylakoid-like structures,which could not form normally.The ALM1 gene encodes a chloroplast-localized superoxide dismutase.Full-length ALM1 successfully restored the non-albino phenotype,and in knockout lines,the albino phenotype reappeared.The ALM1gene is expressed mainly in young leaves.alm1 plants died as a consequence of excessive reactive oxygen accumulation after the third-leaf stage.A series of biochemical assays verified that ALM1 interacted with the OsTrxz protein,which is one of the components of plastid-encoded RNA polymerase (PEP) complexes.A western blot experiment indicated that ALM1 played an important role in stabilizing OsTrxz in rice.An overexpression test of ALM1 revealed that ALM1 can increase drought resistance by removing excess reactive oxygen in rice seedlings.This study suggests that ALM1 not only participates in rice chloroplast biogenesis,but also increases rice stress resistance by scavenging excess reactive oxygen.

亲水性添加剂二甲基甲酰胺对聚酰胺反渗透膜性能的影响

详细研究了在间苯二胺(MPD)水相中添加亲水性溶剂二甲基甲酰胺(DMF)对聚酰胺复合膜表面形貌和分离性能的影响。随着DMF浓度的增加,聚酰胺分离层表面逐渐形成连续扁平的片状结构,厚度和表面粗糙度均逐渐减小。尤其是DMF的加入能够在提高复合膜通量的同时避免截留率大幅降低。其原因是DMF一方面降低了MPD向有机相中的扩散速率,另一方面促进了聚合反应的进行,致使MPD与均苯三甲酰氯(TMC)只能在更薄的区域内反应,从而最终形成更薄的聚酰胺分离层,以及层内更加扁平连续的片状结构。

CO flux of soil respiration in natural recovering karst abandoned farmland in Southwest China

To estimate carbon sequestration potential in the karst area,soil respiration in a natural recovering karst abandoned farmland in Shawan,Puding,Guizhou,southwest China was continuously and automatically monitored for more than two years.The results show that the CO2flux of soil respiration(2.63±1.89 lmol m^-2s-^1)is higher in the karst area than in non-karst areas under similar conditions but that regional value(1.32 lmol m-2s-1)is lower because of larger rock fragment coverage(~50%).A the same time,the temperature sensitivity of soil respiration(Q10)in this study area is significantly higher than that of non-karst areas under similar conditions.Soil respiration has an obvious temporal variation,which is reflected in a significant exponential relationship between soil respiration and soil temperature,but the relationship between soil respiration and soil moisture is very complex.Especially soil respiration has an obvious spatial variation,which is likely affected by different diffusion or water-rock reaction processes.

Industrial X-Ray Image Enhancement Algorithm based on AH and MSR

An X-ray image enhancement algorithm based on AH(adaptive histogram) and MSR( Multi-scale Retinex )algorithm is proposed in this paper for the industrial X-ray image, which contrast is low, and the detail features is poor. Firstly, the contrast limited adaptive histogram equalization and neighborhood algorithm is used for the image. Then the mapping is built between the image and the detail scales by the enhance function ratio rules, which is adjusted by the local contracting information. Finally, according the enhance function radios, the reconstructed image is rebuild. Compared with other image enhancement algorithms, experimental results show that our algorithm can improve the global image effectively, moreover it overcomes the visible artifacts of X-ray image. Therefore, the x-ray image becomes clearer, and a better perceptual image is acquired for the image feature recognizing and matching.

Development and drought tolerance assay of marker-free transgenic rice with OsAPX2 using biolistic particle-mediated co-transformation

Abiotic stresses such as drought, salinity, and low temperature cause–losses in rice production worldwide. The emergence of transgenic technology has enabled improvements in the drought resistance of rice plants and helped avert crop damage due to drought stress.Selectable marker genes conferring resistance to antibiotics or herbicides have been widely used to identify genetically modified plants. However, the use of such markers has limited the public acceptance of genetically modified organisms. Marker-free materials (i.e., those containing a single foreign gene) may be more easily accepted by the public and more likely to find common use. In the present study, we created marker-free drought-tolerant transgenic rice plants using particle bombardment. Overall, 842 T_0plants overexpressing the rice ascorbate peroxidase-coding gene OsAPX2 were generated. Eight independentmarker-free lines were identified from T_1 seedlings using the polymerase chain reaction.The molecular characteristics of these lines were examined, including the expression level,copy number, and flanking sequences of OsAPX2, in the T_2 progeny. A simulated drought test using polyethylene glycol and a drought-tolerance test of seedlings confirmed that the marker-free lines carrying OsAPX2 showed significantly improved drought tolerance in seedlings. In the field, the yield of the wild-type plant decreased by 60% under drought conditions compared with normal conditions. However, the transgenic line showed a yield loss of approximately 26%. The results demonstrated that marker-free transgenic lines significantly improved grain yield under drought-stressed conditions.

Molecular Cloning and Expression Analysis of zm NAC Transcription Factor Gene

In order to study NAC transcription factor gene in maize(Zea mays), a completed c NAC encoding the NAC-like gene homologue named as Zm NAC was cloned from the maize inbred line Zheng 58 using a pair of specific primers, which were designed to cover the full coding region according to the reported NAC gene family. The length of the sequences was 953 bp.The deduced amino acid sequences analysis showed that the sequence contained the complete coding region of a typical NAC gene, including a complete open reading frame which was 939 bp. The study analyzed the expression patterns of NAC transcript gene induced in various PEG(polyethylene glycol) simulated drought condition. Real-time PCR indicated that maize NAC gene can be induced in various PEG to abiotic stress responses, it could express constitutively to adopt the drought condition in short time, and the higher drought, the more early expression, which indicated that NAC transcript gene could be involved in the regulation of the defense response.

Recent Advances in Photochemical/Electrochemical Carboxylation of Olefins with CO_(2)

CO_(2) is an abundant,nontoxic,and renewable C1 feedstock in synthetic chemistry.Direct carboxylation of readily available olefins incorporating CO_(2) is regarded as a promising strategy to access high value-added carboxylic acids as well as CO_(2) fixation.However,due to the thermodynamic stability and kinetic inertness of CO_(2) and the difficulty in controlling the regioselectivity,the carboxylation of olefins with CO_(2) still remains challenging.Radical-type functionalization with olefins represented a powerful protocol and enabled the development of novel transformations in this realm.More recently,the advance of new technology,such as photoredox catalysis and the renaissance of electrochemistry in organic synthesis,offered access to unique chemical reactivities of radical precursors and provided new solutions to the functionalization of olefins.

Cycloaddition Reactions of Epoxides and CO_(2)Catalyzed by Bifunctional Rare-Earth Metal Complexes Bearing Amino-Bridged Tris(phenolato)Ligands

Eight zwitterionic rare earth metal complexes stabilized by amino-bridged tris(phenolato)ligands bearing quaternary ammonium side-arms were synthesized and characterized.These complexes were used as single-component catalysts for the cycloaddition of CO_(2)and epoxides,and their catalytic activities are obviously higher than those of their binary analogues.Further studies revealed that the halide anions(Cl^(–),Br^(–),I^(–))and the metal complexes influenced the catalytic activity,and the lanthanum complex bearing iodide anion showed the highest catalytic activity for this addition reaction.A variety of mono-substituted epoxides were converted to cyclic carbonates in good to excellent yields(55%—99%)with high selectivity(>99%)at 30℃and 1 bar CO_(2),whereas internal epoxides required higher both reaction temperatures(60—120℃)and catalyst loading(2 mol%)for high yields.The catalyst was recyclable for four times without noticeable loss of catalytic activity.Based on the results of kinetic studies and in℃situ IR reactions,a plausible reaction mechanism was proposed.

Selective nickel-electrocatalyzed benzylic C-H oxygenation of functionalized alkyl arenes

Herein, a site-selective paired electrochemical C–H oxidation of functionalized alkyl arenes promoted by nickel catalyst is disclosed. A Ni(Ⅱ)-dioxygen species formed in situ efficiently enable the oxidation process under mild conditions with a broad substrate scope with excellent functional group compatibilities,such as free carboxylic acid, aldehyde, halogen(including aryl iodide), amide and amino acid. The use of the nickel catalyst in combination with water provides a safe, green and economical method for oxidation of a range of molecules varying in complexity and drug derivatives, demonstrating its potential application in organic synthesis and the pharmaceutical industry. Reaction outcomes and mechanistic studies revealed the key role of the in situ Ni(Ⅱ)-dioxygen species for the subsequent oxidation of C(sp^(3))–H bonds,and short-lived reactive intermediates(aryl radical cation) was rapidly captured by the combination of a bipolar ultramicroelectrode(BUME) with nano-electrospray ionization mass spectrometry.

Association of a complete breast cancer pathologic response with axillary lymph node metastasis via neoadjuvant chemotherapy:Results from the CSBrS-012 study

To the Editor:In the last decade,neoadjuvant chemotherapy(NAC)has become a well-accepted treatment option for breast cancer,although few detailed description of NAC in China has yet been reported.[1]A previous study found that among patients with clinically node-negative(cN0)breast cancer,97.7%(432/442)with breast pathologic complete response(bpCR)had ypN0(absence of metastases in the axillary lymph nodes);and 71.6%(882/1232)without bpCR achieved ypN0(P<0.001).As for human epidermal growth factor receptor 2(HER2)positive or triple-negative breast cancer(TNBC)that achieved bpCR.

Organo-electroreduction enables arylcarboxylation of styrenes

Electroreduction offers an alternative to generate high active intermediates from electrophiles(halides, alkenes, etc.) in organic synthesis. However, it still remains challenge to enable the transformations in controlled fashion for substrates with similar reduction potentials. Herein, an electroreductive arylcarboxylation of styrenes with aryl halides and CO_(2)promoted by an organomediator has been developed. The reaction exhibits the remarkable reactivity control between styrenes and aryl halides bearing very similar reduction potentials, which is enabled by the addition of a simple organic mediator. The mediated process for different kinds of aryl halides(iodides and bromides) could be achieved by simply tuning the electronic effect of the skeleton of naphthalene. This protocol displays a broad substrate scope and the extension to late-stage modification of biorelevant molecules and their derivatives showed a bright prospect. Moreover, density functional theory(DFT) calculations and mechanistic studies have been conducted and provide solid support to rationalize the selectivity and reactivity control observed.

The RNA Editing Factor WSP1 Is Essentia for Chloroplast Development in Rice

Although the multiple organellar RNA editing factors （MORFs） in the plastids of Arabidopsis thaliana have been extensively studied, molecular details underlying how MORFs affect plant development in other species, particularly in rice, remain largely unknown. Here we describe the characterization of wspl, a rice mutant with white-stripe leaves and panicles. Notably, wspl exhibited nearly white immature panicles at the heading stage. Transmission electron microscopy analysis and chlorophyll content measurement re- veale i a chloroplast developmental defect and reduced chlorophyll accumulation in wspl. Positional cloning of WSP1 found a point mutation in OsO4g51280, whose putative product shares high sequence similarity with MORF proteins. Complementation experiments demonstrated that WSP1 was responsible for the variegated phenotypes of wspl. WSP1 is localized to chloroplasts and the point mutation in wspl affected the editing of multiple organellar RNA sites. Owing to the defect in plastid RNA editing, chloroplast ribosome biogenesis and ndhA splicing were also impaired in wspl, which may affect normal chloroplast development in the leaves and panicles at the heading stage. Together, our results demonstrate the importance of rice WSP1 protein in chloroplast development and broaden our knowledge about MORF family members in rice.