The neutron capture cross sections(n,γ)of bromine were obtained using the time-of-flight technique at the Back-n facility of the China Spallation Neutron Source.Promptγ-rays originating from neutron-induced capture ...The neutron capture cross sections(n,γ)of bromine were obtained using the time-of-flight technique at the Back-n facility of the China Spallation Neutron Source.Promptγ-rays originating from neutron-induced capture events were detected using four C_(6)D_(6) detectors.The pulse-height weighting technique and double-bunch unfolding method based on Bayesian theory were used in the data analysis.Background deductions,normalization,and corrections were carefully considered to obtain reliable measurement results.The multilevel R-matrix Bayesian code SAMMY was used to extract the resonance parameters in the resolved resonance region(RRR).The average cross sections in the unresolved resonance region(URR)were obtained from 10 to 400 keV.The experimental results were compared with data from several evaluated libraries and previous experi-ments in the RRR and URR.The TALYS code was used to describe the average cross sections in the URR.The astrophysical Maxwell average cross sections(MACSs)of ^(79,81)Br from kT=5 to 100 keV were calculated over a sufficiently wide range of neutron energies.At a thermal energy of kT=30 keV,the MACS value for ^(79)Br 682±68 mb was in good agreement with the KADoNiS v1.0 recommended value.By contrast,the value of 293±29 mb for ^(81)Br was substantially higher than that of the evaluated database and the KADoNiS v1.0 recommended value.展开更多
Piezoelectric materials have advantages of fine-tuning photocatalytic performance through harvesting mechanical energy and open a new avenue in facilitating green catalytic reaction.Herein,polyvinylidene fluoride(PVDF...Piezoelectric materials have advantages of fine-tuning photocatalytic performance through harvesting mechanical energy and open a new avenue in facilitating green catalytic reaction.Herein,polyvinylidene fluoride(PVDF),a flexible piezoelectric material,was introduced to synthesize a novel Cd_(0.9)Zn_(0.1)S-ZnO@C/PVDF(CZS-ZO@C/PVDF)piezo-photocatalytic film by spin coating and immersion phase conversion method.Benefiting from the piezoelectricity of PVDF and the internal electric field(IEF)of CZS-ZO@C Step-scheme(S-Scheme)heterojunction,CZS-ZO@C/PVDF was able to induce a hydrogen generation rate of 34.9 mmol g^(−1)h^(−1)activated by ultrasound and visible light(U-L),which is∼17.5 times of Cd_(0.9)Zn_(0.1)S/PVDF(CZS/PVDF)and∼7.4 times of the photocatalysis rate activated by visible light only(L).Piezoelectric measurements and COMSOL simulation illustrated the excellent piezoelectricity of CZS-ZO@C/PVDF film,which exhibits a piezoelectric coefficient(d33)of 9.9 pm V−1 and a piezoelectric potential of 874 mV(under 0.5 MPa).The reaction mechanism for the exceptional piezo-photocatalytic performance was finally disclosed through density functional theory(DFT)calculation and electrochemical tests.This study enriches the application scope of piezoelectric materials in sustainable energy catalysis and provides a new direction to develop efficient piezoelectric photocatalysts.展开更多
BACKGROUND The prevalence of female infertility between the ages of 25 and 44 is 3.5%to 16.7%in developed countries and 6.9%to 9.3%in developing countries.This means that infertility affects one in six couples and is ...BACKGROUND The prevalence of female infertility between the ages of 25 and 44 is 3.5%to 16.7%in developed countries and 6.9%to 9.3%in developing countries.This means that infertility affects one in six couples and is recognized by the World Health Organization as the fifth most serious global disability.The International Committee for Monitoring Assisted Reproductive Technology reported that the global total of babies born as a result of assisted reproductive technology procedures and other advanced fertility treatments is more than 8 million.Advancements in controlled ovarian hyperstimulation procedures led to crucial accomplishments in human fertility treatments.The European Society for Human Reproduction and Embryology guideline on ovarian stimulation gave us valuable evidence-based recommendations to optimize ovarian stimulation in assisted reproductive technology.Conventional ovarian stimulation protocols for in vitro fertilization(IVF)–embryo transfer are based upon the administration of gonadotropins combined with gonadotropin-releasing hormone(GnRH)analogues,either GnRH agonists(GnRHa)or antagonists.The development of ovarian cysts requires the combination of GnRHa and gonadotropins for controlled ovarian hyperstimulation.However,in rare cases patients may develop an ovarian hyper response after administration of GnRHa alone.CASE SUMMARY Here,two case studies were conducted.In the first case,a 33-year-old female diagnosed with polycystic ovary syndrome presented for her first IVF cycle at our reproductive center.Fourteen days after triptorelin acetate was administrated(day 18 of her menstrual cycle),bilateral ovaries presented polycystic manifestations.The patient was given 5000 IU of human chorionic gonadotropin.Twenty-two oocytes were obtained,and eight embryos formed.Two blastospheres were transferred in the frozen-thawed embryo transfer cycle,and the patient was impregnated.In the second case,a 37-year-old woman presented to the reproductive center for her first donor IVF cycle.Fourteen days after GnRHa administration,the transvaginal ultrasound revealed six follicles measuring 17-26 mm in the bilateral ovaries.The patient was given 10000 IU of human chorionic gonadotropin.Three oocytes were obtained,and three embryos formed.Two high-grade embryos were transferred in the frozen-thawed embryo transfer cycle,and the patient was impregnated.CONCLUSION These two special cases provide valuable knowledge through our experience.We hypothesize that oocyte retrieval can be an alternative to cycle cancellation in these conditions.Considering the high progesterone level in most cases of this situation,we advocate freezing embryos after oocyte retrieval rather than fresh embryo transfer.展开更多
AIM: To evaluate the impact of alcohol dehydrogenase-2 (ADH2) and aldehyde dehydrogenase-2 (ALDH2) polymorphisms on esophageal cancer susceptibility in Southeast Chinese males.METHODS: Two hundred and twenty-one...AIM: To evaluate the impact of alcohol dehydrogenase-2 (ADH2) and aldehyde dehydrogenase-2 (ALDH2) polymorphisms on esophageal cancer susceptibility in Southeast Chinese males.METHODS: Two hundred and twenty-one esophageal cancer patients and 292 healthy controls from Taixing city in Jiangsu Province were enrolled in this study. ADH2 and ALDH2 genotypes were examined by polymerase chain reaction and denaturing high-performance liquid chromatography. Unconditional logistic regression was used to calculate the odds ratios (OR) and 95% confidence interval (CI).RESULTS: The ADH G allele carriers were more susceptible to esophageal cancer, but no association was found between ADH2 genotypes and risk of esophageal cancer when disregarding alcohol drinking status. Regardless of ADH2 genotype, ALDH2G/A or A/A carriers had significantly increased risk of developing esophageal cancer, with homozygous individuals showing higher esophageal cancer risk than those who were heterozygous. A significant interaction between ALDH2 and drinking was detected regarding esophageal cancer risk; the OR was 3.05 (95% CI: 2.49-6.25). Compared with non-drinkers carrying both ALDH2 G/G and ADH2 A/A, drinkers carrying both ALDH2 A allele and ADH2 G allele showed a significantly higher risk of developing esophageal cancer (OR = 8.36, 95% CI: 2.98-23.46).CONCLUSION: Both ADH2 G allele and ALDH2 A allele significantly increase the risk of esophageal cancer development in Southeast Chinese males. ALDH2 A allele significantly increases the risk of esophageal cancer development especially in alcohol drinkers. Alcohol drinkers carrying both ADH2 G allele and ALDH2 A allele have a higher risk of developing esophageal cancer.展开更多
<div style="text-align:justify;"> In the channel estimation for ultraviolet communication, the single scattering power is usually used to approximate the received total power. This approximation error ...<div style="text-align:justify;"> In the channel estimation for ultraviolet communication, the single scattering power is usually used to approximate the received total power. This approximation error is affected by the transceiver configuration. Here, we employ the proportion of received single scattering power in received total power to indicate the approximation error of the single scattering model in different configurations. This is useful for reducing the approximation error by selecting a more appropriate transceiver configuration. </div>展开更多
BACKGROUND: Pseudomonas aeruginosa mannose-sensitive hemagglutinin (PA-MSHA) parenteral injection is used as a broad-spectrum immunomodulator. It remains unclear whether PA-MSHA exhibits inhibitory effects on tumor...BACKGROUND: Pseudomonas aeruginosa mannose-sensitive hemagglutinin (PA-MSHA) parenteral injection is used as a broad-spectrum immunomodulator. It remains unclear whether PA-MSHA exhibits inhibitory effects on tumor cell growth. OBJECTIVE: To investigate inhibitory mechanisms of PA-MSHA-induced proliferation in rat C6 glioma cells in vitro. DESIGN, TIME AND SETTING: Comparative observation and in vitro experiments were performed at the Key Laboratory of Natural Medicine, Kunming Medical College, China from July 2008 to April 2009. MATERIALS: Rat C6 glioma cell line (Shanghai Institute of Cell Biology, Chinese Academy of Sciences, China) and PA-MSHA parenteral injection (Beijing Wanteer Bio-Pharmaceutical, China) were used in the present study. METHODS: Rat C6 glioma cells in logarithmic growth phase were harvested in vitro. Adherent monolayer cells were respectively treated with PA-MSHA at final colony-forming units (cfu) of 1 ×10^8 cfu/mL, 2 × 10^8 cfu/mL, 4 × 10^8 cfu/mL, 6 × 10^8 cfu/mL, and 8 ×10^8 cfu/mL following 24 hours of conventional culture. MAIN OUTCOME MEASURES: MTT colorimetric assay was utilized to determine the inhibitory rate of C6 glioma cells following treatment with various concentrations of PA-MSHA at different times. Cell apoptosis was detected by fluorescent microscopy following Hoechst 33258 staining. Flow cytometry was used to measure PA-MSHA effects on C6 cell cycle. RESULTS: Inhibitory rate of C6 glioma cells increased with prolonged time and increased dose. Hoechst 33258 staining revealed obvious morphological changes in apoptotic C6 glioma cells. Flow cytometry revealed hypodiploid peaks, Le., apoptotic peak, and the apoptotic rate in cells during S-phase significantly increased with increased concentrations in the experimental groups. CONCLUSION: With in vitro experiments, PA-MSHA preparations inhibited C6 glioma cell proliferation in a time- and dose-dependent manner. These mechanisms are likely associated with cell apoptosis induction and inhibition of the S phase.展开更多
Aporphine alkaloids have diverse pharmacological activities;however,our understanding of their biosynthesis is relatively limited.Previous studies have classified aporphine alkaloids into two categories based on the c...Aporphine alkaloids have diverse pharmacological activities;however,our understanding of their biosynthesis is relatively limited.Previous studies have classified aporphine alkaloids into two categories based on the configuration and number of substituents of the D-ring and have proposed preliminary biosynthetic pathways for each category.In this study,we identified two specific cytochrome P450 enzymes(CYP80G6 and CYP80Q5)with distinct activities toward(S)-configured and(R)-configured substrates from the herbaceous perennial vine Stephania tetrandra,shedding light on the biosynthetic mechanisms and stereochemical features of these two aporphine alkaloid categories.Additionally,we characterized two CYP719C enzymes(CYP719C3 and CYP719C4)that catalyzed the formation of the methylenedioxy bridge,an essential pharmacophoric group,on the A-and D-rings,respectively,of aporphine alkaloids.Leveraging the functional characterization of these crucial cytochrome P450 enzymes,we reconstructed the biosynthetic pathways for the two types of aporphine alkaloids in budding yeast(Saccharomyces cerevisiae)for the de novo production of compounds such as(R)-glaziovine,(S)-glaziovine,and magnoflorine.This study provides key insight into the biosynthesis of aporphine alkaloids and lays a foundation for producing these valuable compounds through synthetic biology.展开更多
Cytochrome P450 enzymes play a crucial role as catalysts in the biosynthesis of numerous plant natural products(PNPs).Enhancing the catalytic activity of P450s in host microorganisms is essential for the efficient pro...Cytochrome P450 enzymes play a crucial role as catalysts in the biosynthesis of numerous plant natural products(PNPs).Enhancing the catalytic activity of P450s in host microorganisms is essential for the efficient production of PNPs through synthetic biology.In this study,we engineered Saccharomyces cerevisiae to optimize the microenvironment for boosting the activities of P450s,including coexpression with the redox partner genes,enhancing NADPH supply,expanding the endoplasmic reticulum(ER),strengthening heme biosynthesis,and regulating iron uptake.This created a platform for the efficient production 11,20-dihydroxyferruginol,a key intermediate of the bioactive compound tanshinones.The yield was enhanced by 42.1-fold through 24 effective genetic edits.The optimized strain produced up to 67.69±1.33 mg/L 11,20-dihydroxyferruginol in shake flasks.Our work represents a promising advancement toward constructing yeast cell factories containing P450s and paves the way for microbial biosynthesis of tanshinones in the future.展开更多
Recently,there has been increased attention toward 3D imaging using single-pixel single-photon detection(also known as temporal data)due to its potential advantages in terms of cost and power efficiency.However,to eli...Recently,there has been increased attention toward 3D imaging using single-pixel single-photon detection(also known as temporal data)due to its potential advantages in terms of cost and power efficiency.However,to eliminate the symmetry blur in the reconstructed images,a fixed background is required.This paper proposes a fusion-data-based 3D imaging method that utilizes a single-pixel single-photon detector and millimeter-wave radar to capture temporal histograms of a scene from multiple perspectives.Subsequently,the 3D information can be reconstructed from the one-dimensional fusion temporal data by using an artificial neural network.Both the simulation and experimental results demonstrate that our fusion method effectively eliminates symmetry blur and improves the quality of the reconstructed images.展开更多
The polarized electric field inside piezoelectric materials has been proven to be a promising technique to boost photogenerated charge separation.Herein,a novel flexible SnFe_(2)O_(4)/ZnIn_(2)S_(4)/polyvinylidene fluo...The polarized electric field inside piezoelectric materials has been proven to be a promising technique to boost photogenerated charge separation.Herein,a novel flexible SnFe_(2)O_(4)/ZnIn_(2)S_(4)/polyvinylidene fluoride((CH2CF2)_(n),PVDF)(P-SZ)film piezophotocatalyst was successfully synthesized by combining PVDF,an organic piezoelectric material,with a SnFe_(2)O_(4)/ZnIn_(2)S_(4)(SFO/ZIS)type II heterojunction photocatalyst.The hydrogen evolution rate of SFO/ZIS heterojunction with a SFO content of 5%is about 846.79μmol·h^(−1)·g^(−1),which is 3.6 times that of pristine ZIS.Furthermore,after being combined with PVDF,the optimum hydrogen evolution rate of P-SZ is about 1652.7μmol·h^(−1)·g^(−1)in the presence of ultrasound,which exceeds that of 5%SFO/ZIS by an approximate factor of 2.0.Based on experimental results,the mechanism of the improved photocatalytic performance of P-SZ was proposed on the basis of the piezoelectric field in PVDF and the formed heterojunction between SFO and ZIS,which effectively boosted the separation of photoinduced charges.This work provides an efficient strategy for multi-path collection and utilization of natural solar and vibrational energy to enhance photoactivity.展开更多
Through systematic investigations using the axially deformed solutions of the Skyrme-Hartree-Fock-Bogoliubov equations with 132 sets of Skyrme interaction parameters,it is confirmed that the neutron-skin thickness(Sn)...Through systematic investigations using the axially deformed solutions of the Skyrme-Hartree-Fock-Bogoliubov equations with 132 sets of Skyrme interaction parameters,it is confirmed that the neutron-skin thickness(Sn)of a neutron-rich nucleus is proportional to the difference between the proton radii of mirror nuclei(R_(p)^(mir)).This indicates that Sn may be deduced from R_(p)^(mir).Compared with the results of the Skyrme-Hartree-Fock model,pairing effects are found to enhance the correlation for most mirror pairs,whereas deformation effects may weaken the correlation.Furthermore,the correlation between Sn and R_(p)^(mir) is studied for isotones with N=20 and N=28,which reveals a stronger linear correlation with increasing|N−Z|.This result demonstrates that it is possible to extract the neutron-skin thickness of an unstable nucleus from the proton radii difference of the mirror nuclei of its isotones.展开更多
In this Let ter,a single scattering turbulence model in a narrow beam case for ultraviolet(UV)communication is proposed based on the division of the effective scattering volume.This model takes the variation of atmosp...In this Let ter,a single scattering turbulence model in a narrow beam case for ultraviolet(UV)communication is proposed based on the division of the effective scattering volume.This model takes the variation of atmospheric scattering,absorption,and turbulence in different paths into account.Meanwhile,the applicable transceiver configurations of this model are provided by analyzing path loss error caused by the single scattering assumption in the UV channel.Furthermore,we investigate the effect of turbulence on the probability density function of the arriving power in both coplanar and non-coplanar scenarios.The averaging effect of multipath propagation on the arriving power's fluctuations is presented.Then,the bit-error-rate performance is also studied.This work provides an efficient way for UV turbulence channel estimation.展开更多
Sterol C24-methyltransferase(SMT) plays multiple important roles in plant growth and development. SMT1, which belongs to the family of transferases and transforms cycloartenol into 24-methylene cycloartenol, is involv...Sterol C24-methyltransferase(SMT) plays multiple important roles in plant growth and development. SMT1, which belongs to the family of transferases and transforms cycloartenol into 24-methylene cycloartenol, is involved in the biosynthesis of 24-methyl sterols. Here, we report the cloning and characterization of a cDNA encoding a sterol C24-methyltransferase from Tripterygium wilfordii(Tw SMT1). Tw SMT1(Gen Bank access number KU885950) is a 1530 bp cDNA with a 1041 bp open reading frame predicted to encode a 346-amino acid, 38.62 k Da protein. The polypeptide encoded by the SMT1 cDNA was expressed and purified as a recombinant protein from Escherichia coli(E. coli) and showed SMT activity. The expression of Tw SMT1 was highly up-regulated in T. wilfordii cell suspension cultures treated with methyl jasmonate(Me JA). Tissue expression pattern analysis showed higher expression in the phellem layer compared to the other four organs(leaf, stem, xylem and phloem), which is about ten times that of the lowest expression in leaf. The results are meaningful for the study of sterolbiosynthesis of T. wilfordii and will further lay the foundations for the research in regulating both the content of other main compounds and growth and development of T. wilfordii.展开更多
The 4-hydroxy-3-methylbut-2-enyl diphosphate reductase(HDR) is the last step key enzyme of the methylerythritol phosphate(MEP) pathway,synthesizing isopentenyl diphosphate and its allyl isomer dimethylallyl diphosphat...The 4-hydroxy-3-methylbut-2-enyl diphosphate reductase(HDR) is the last step key enzyme of the methylerythritol phosphate(MEP) pathway,synthesizing isopentenyl diphosphate and its allyl isomer dimethylallyl diphosphate,which is important for regulation of isoprenoid biosynthesis.Here the full-length cDNA of HDR,designated TwHDR(GenBank Accession No.KJ933412.1),was isolated from Tripterygium wilfordii for the first time.TwHDR has an open reading frame(ORF) of 1386 bp encoding461 amino acids.TwHDR exhibits high homology with HDRs of other plants,with an N-terminal conserved domain and three conserved cysteine residues.TwHDR cDNA was cloned into an expression vector and transformed into an Escherichia coli hdr mutant.Since loss-of-function E.coli hdr mutant is lethal,the result showed that transformation of TwHDR cDNA rescued the E.coli hdr mutant.This complementation assay suggests that the TwHDR cDNA encodes a functional HDR enzyme.The expression of TwHDR was induced by methyl-jasmonate(MJ) in T.wilfordii suspension cells.The expression of TwHDR reached the highest level after 1 h of MJ treatment.These results indicate that we have identified a functional TwHDR enzyme,which may play a pivotal role in the biosynthesis of diterpenoid triptolide in T.wilfordii.展开更多
Tripterygium wilfordii is a valuable medicinal plant rich in biologically active diterpenoids,but there are few studies on the origins of these diterpenoids in its secondary metabolism.Here,we identified three regions...Tripterygium wilfordii is a valuable medicinal plant rich in biologically active diterpenoids,but there are few studies on the origins of these diterpenoids in its secondary metabolism.Here,we identified three regions containing tandemly duplicated diterpene synthase genes on chromosomes(Chr) 17 and 21 of T. wilfordii and obtained 11 diterpene synthases with different functions.We farther revealed that these diterpene synthases underwent duplication and rearrangement at approximately 2.3-23.7 million years ago(MYA) by whole-genome triplication(WGT),transposon mediation,and tandem duplication,followed by functional divergence.We first demonstrated that four key amino acids in the sequences of TwCPS3,TwCPS5,and TwCPSS were altered during evolution,leading to their functional divergence and the formation of diterpene secondary metabolites.Then,we demonstrated that the functional divergence of three TwKSLs was driven by mutations in two key amino acids.Finally,we discovered the mechanisms of evolution and pseudogenization of miltiradiene synthases in T.wilfordii and elucidated that the new function in TwMS1/2 from the terpene synthase(TPS)-b subfamily was caused by progressive changes in multiple amino acids after the WGT event.Our results provide key evidence for the formation of diverse diterpenoids during the evolution of secondary metabolites in T.wilfordii.展开更多
Dopamine D1 receptors(D1Rs) play a key role in cocaine addiction, and multiple protein kinases such as GRKs, PKA, and PKC are involved in their phosphorylation. Recently, we reported that protein kinase D1 phosphory...Dopamine D1 receptors(D1Rs) play a key role in cocaine addiction, and multiple protein kinases such as GRKs, PKA, and PKC are involved in their phosphorylation. Recently, we reported that protein kinase D1 phosphorylates the D1 R at S421 and promotes its membrane localization. Moreover, this phosphorylation of S421 is required for cocaineinduced behaviors in rats. In the present study, we generated transgenic mice over-expressing S421A-D1 R in the forebrain. These transgenic mice showed reduced phospho-D1R(S421) and its membrane localization, and reduced downstream ERK1/2 activation in the striatum. Importantly, acute and chronic cocaine-induced locomotor hyperactivity and conditioned place preference were significantly attenuated in these mice. These findings provide in vivo evidence for the critical role of S421 phosphorylation of the D1 R in its membrane localization and in cocaine-induced behaviors. Thus, S421 on the D1 R represents a potential pharmacotherapeutic target for cocaine addiction and other drug-abuse disorders.展开更多
Borneol is a precious monoterpenoid with two chiral structures,(-)-borneol and(+)-borneol.Bornyl diphosphate synthase is the key enzyme in the borneol biosynthesis pathway.Many(+)-bornyl diphosphate synthases have bee...Borneol is a precious monoterpenoid with two chiral structures,(-)-borneol and(+)-borneol.Bornyl diphosphate synthase is the key enzyme in the borneol biosynthesis pathway.Many(+)-bornyl diphosphate synthases have been reported,but no(-)-bornyl diphosphate synthases have been identified.Blumea balsamifera leaves are rich in borneol,almost all of which is(-)-borneol.In this study,we identified a high-efficiency(-)-bornyl diphosphate synthase(BbTPS3)from B.balsamifera that converts geranyl diphosphate(GPP)to(-)-bornyl diphosphate,which is then converted to(-)-borneol after dephosphorylation in vitro.BbTPS3 exhibited a K m value of 4.93±1.38μM for GPP,and the corresponding k cat value was 1.49 s−1.Multiple strategies were applied to obtain a high-yielding(-)-borneol producing yeast strain.A codon-optimized BbTPS3 protein was introduced into the GPP high-yield strain MD,and the resulting MD-B1 strain produced 1.24 mg⋅L^(-1)(-)-borneol.After truncating the N-terminus of BbTPS3 and adding a Kozak sequence,the(-)-borneol yield was further improved by 4-fold to 4.87 mg⋅L^(-1).Moreover,the(-)-borneol yield was improved by expressing the fusion protein module of ERG20 F96W-N127W-YRSQI-t14-BbTPS3K2,resulting in a final yield of 12.68 mg⋅L^(-1) in shake flasks and 148.59 mg⋅L^(-1) in a 5-L bioreactor.This work is the first reported attempt to produce(-)-borneol by microbial fermentation.展开更多
Objective: To clone and investigate two dehydrodolichyl diphosphate synthase genes of Tripterygium wilfordii by bioinformatics and tissue expression analysis. Materials and Methods: According to the T. wifordii transc...Objective: To clone and investigate two dehydrodolichyl diphosphate synthase genes of Tripterygium wilfordii by bioinformatics and tissue expression analysis. Materials and Methods: According to the T. wifordii transcriptome database, specific primers were designed to clone the TwDHDDS1 and TwDHDDS2 genes via PCR. Based on the cloned sequences, protein structure prediction, multiple sequence alignment and phylogenetic tree construction were performed. The expression levels of the genes in different tissues of T. wilfordii were measured by real?time quantitative PCR. Results: The TwDHDDS1 gene encompassed a 873 bp open reading frame(ORF) and encoded a protein of 290 amino acids. The calculated molecular weight of the translated protein was about 33.46 kDa, and the theoretical isoelectric point(pI) was 8.67. The TwDHDDS2 encompassed a 768 bp ORF, encoding a protein of 255 amino acids with a calculated molecular weight of about 21.19 kDa, and a theoretical isoelectric point(pI) of 7.72. Plant tissue expression analysis indicated that TwD HDDS1 and TwDHDDS2 both have relatively ubiquitous expression in all sampled organ tissues, but showed the highest transcription levels in the stems. Conclusions: The results of this study provide a basis for further functional studies of TwDHDDS1 and TwDHDDS2. Most importantly, these genes are promising genetic targets for the regulation of the biosynthetic pathways of important bioactive terpenoids such as triptolide.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.U1832182,11875328,11761161001,and U2032137)the Natural Science Foundation of Guangdong Province,China(Nos.18zxxt65 and 2022A1515011184)+3 种基金the Science and Technology Development Fund,Macao SAR(Grant No.008/2017/AFJ)the Macao Young Scholars Program of China(No.AM201907)the China Postdoctoral Science Foundation(Nos.2016LH0045 and 2017M621573)the Fundamental Research Funds for the Central Universities(Nos.22qntd3101 and 2021qntd28).
文摘The neutron capture cross sections(n,γ)of bromine were obtained using the time-of-flight technique at the Back-n facility of the China Spallation Neutron Source.Promptγ-rays originating from neutron-induced capture events were detected using four C_(6)D_(6) detectors.The pulse-height weighting technique and double-bunch unfolding method based on Bayesian theory were used in the data analysis.Background deductions,normalization,and corrections were carefully considered to obtain reliable measurement results.The multilevel R-matrix Bayesian code SAMMY was used to extract the resonance parameters in the resolved resonance region(RRR).The average cross sections in the unresolved resonance region(URR)were obtained from 10 to 400 keV.The experimental results were compared with data from several evaluated libraries and previous experi-ments in the RRR and URR.The TALYS code was used to describe the average cross sections in the URR.The astrophysical Maxwell average cross sections(MACSs)of ^(79,81)Br from kT=5 to 100 keV were calculated over a sufficiently wide range of neutron energies.At a thermal energy of kT=30 keV,the MACS value for ^(79)Br 682±68 mb was in good agreement with the KADoNiS v1.0 recommended value.By contrast,the value of 293±29 mb for ^(81)Br was substantially higher than that of the evaluated database and the KADoNiS v1.0 recommended value.
基金supported by the Shandong Provincial Natural Science Foundation,China(ZR2022ME179,ZR2021ME046).
文摘Piezoelectric materials have advantages of fine-tuning photocatalytic performance through harvesting mechanical energy and open a new avenue in facilitating green catalytic reaction.Herein,polyvinylidene fluoride(PVDF),a flexible piezoelectric material,was introduced to synthesize a novel Cd_(0.9)Zn_(0.1)S-ZnO@C/PVDF(CZS-ZO@C/PVDF)piezo-photocatalytic film by spin coating and immersion phase conversion method.Benefiting from the piezoelectricity of PVDF and the internal electric field(IEF)of CZS-ZO@C Step-scheme(S-Scheme)heterojunction,CZS-ZO@C/PVDF was able to induce a hydrogen generation rate of 34.9 mmol g^(−1)h^(−1)activated by ultrasound and visible light(U-L),which is∼17.5 times of Cd_(0.9)Zn_(0.1)S/PVDF(CZS/PVDF)and∼7.4 times of the photocatalysis rate activated by visible light only(L).Piezoelectric measurements and COMSOL simulation illustrated the excellent piezoelectricity of CZS-ZO@C/PVDF film,which exhibits a piezoelectric coefficient(d33)of 9.9 pm V−1 and a piezoelectric potential of 874 mV(under 0.5 MPa).The reaction mechanism for the exceptional piezo-photocatalytic performance was finally disclosed through density functional theory(DFT)calculation and electrochemical tests.This study enriches the application scope of piezoelectric materials in sustainable energy catalysis and provides a new direction to develop efficient piezoelectric photocatalysts.
文摘BACKGROUND The prevalence of female infertility between the ages of 25 and 44 is 3.5%to 16.7%in developed countries and 6.9%to 9.3%in developing countries.This means that infertility affects one in six couples and is recognized by the World Health Organization as the fifth most serious global disability.The International Committee for Monitoring Assisted Reproductive Technology reported that the global total of babies born as a result of assisted reproductive technology procedures and other advanced fertility treatments is more than 8 million.Advancements in controlled ovarian hyperstimulation procedures led to crucial accomplishments in human fertility treatments.The European Society for Human Reproduction and Embryology guideline on ovarian stimulation gave us valuable evidence-based recommendations to optimize ovarian stimulation in assisted reproductive technology.Conventional ovarian stimulation protocols for in vitro fertilization(IVF)–embryo transfer are based upon the administration of gonadotropins combined with gonadotropin-releasing hormone(GnRH)analogues,either GnRH agonists(GnRHa)or antagonists.The development of ovarian cysts requires the combination of GnRHa and gonadotropins for controlled ovarian hyperstimulation.However,in rare cases patients may develop an ovarian hyper response after administration of GnRHa alone.CASE SUMMARY Here,two case studies were conducted.In the first case,a 33-year-old female diagnosed with polycystic ovary syndrome presented for her first IVF cycle at our reproductive center.Fourteen days after triptorelin acetate was administrated(day 18 of her menstrual cycle),bilateral ovaries presented polycystic manifestations.The patient was given 5000 IU of human chorionic gonadotropin.Twenty-two oocytes were obtained,and eight embryos formed.Two blastospheres were transferred in the frozen-thawed embryo transfer cycle,and the patient was impregnated.In the second case,a 37-year-old woman presented to the reproductive center for her first donor IVF cycle.Fourteen days after GnRHa administration,the transvaginal ultrasound revealed six follicles measuring 17-26 mm in the bilateral ovaries.The patient was given 10000 IU of human chorionic gonadotropin.Three oocytes were obtained,and three embryos formed.Two high-grade embryos were transferred in the frozen-thawed embryo transfer cycle,and the patient was impregnated.CONCLUSION These two special cases provide valuable knowledge through our experience.We hypothesize that oocyte retrieval can be an alternative to cycle cancellation in these conditions.Considering the high progesterone level in most cases of this situation,we advocate freezing embryos after oocyte retrieval rather than fresh embryo transfer.
基金Supported by Grant from Department of Health,No.H200526,Jiangsu Province,China
文摘AIM: To evaluate the impact of alcohol dehydrogenase-2 (ADH2) and aldehyde dehydrogenase-2 (ALDH2) polymorphisms on esophageal cancer susceptibility in Southeast Chinese males.METHODS: Two hundred and twenty-one esophageal cancer patients and 292 healthy controls from Taixing city in Jiangsu Province were enrolled in this study. ADH2 and ALDH2 genotypes were examined by polymerase chain reaction and denaturing high-performance liquid chromatography. Unconditional logistic regression was used to calculate the odds ratios (OR) and 95% confidence interval (CI).RESULTS: The ADH G allele carriers were more susceptible to esophageal cancer, but no association was found between ADH2 genotypes and risk of esophageal cancer when disregarding alcohol drinking status. Regardless of ADH2 genotype, ALDH2G/A or A/A carriers had significantly increased risk of developing esophageal cancer, with homozygous individuals showing higher esophageal cancer risk than those who were heterozygous. A significant interaction between ALDH2 and drinking was detected regarding esophageal cancer risk; the OR was 3.05 (95% CI: 2.49-6.25). Compared with non-drinkers carrying both ALDH2 G/G and ADH2 A/A, drinkers carrying both ALDH2 A allele and ADH2 G allele showed a significantly higher risk of developing esophageal cancer (OR = 8.36, 95% CI: 2.98-23.46).CONCLUSION: Both ADH2 G allele and ALDH2 A allele significantly increase the risk of esophageal cancer development in Southeast Chinese males. ALDH2 A allele significantly increases the risk of esophageal cancer development especially in alcohol drinkers. Alcohol drinkers carrying both ADH2 G allele and ALDH2 A allele have a higher risk of developing esophageal cancer.
文摘<div style="text-align:justify;"> In the channel estimation for ultraviolet communication, the single scattering power is usually used to approximate the received total power. This approximation error is affected by the transceiver configuration. Here, we employ the proportion of received single scattering power in received total power to indicate the approximation error of the single scattering model in different configurations. This is useful for reducing the approximation error by selecting a more appropriate transceiver configuration. </div>
文摘BACKGROUND: Pseudomonas aeruginosa mannose-sensitive hemagglutinin (PA-MSHA) parenteral injection is used as a broad-spectrum immunomodulator. It remains unclear whether PA-MSHA exhibits inhibitory effects on tumor cell growth. OBJECTIVE: To investigate inhibitory mechanisms of PA-MSHA-induced proliferation in rat C6 glioma cells in vitro. DESIGN, TIME AND SETTING: Comparative observation and in vitro experiments were performed at the Key Laboratory of Natural Medicine, Kunming Medical College, China from July 2008 to April 2009. MATERIALS: Rat C6 glioma cell line (Shanghai Institute of Cell Biology, Chinese Academy of Sciences, China) and PA-MSHA parenteral injection (Beijing Wanteer Bio-Pharmaceutical, China) were used in the present study. METHODS: Rat C6 glioma cells in logarithmic growth phase were harvested in vitro. Adherent monolayer cells were respectively treated with PA-MSHA at final colony-forming units (cfu) of 1 ×10^8 cfu/mL, 2 × 10^8 cfu/mL, 4 × 10^8 cfu/mL, 6 × 10^8 cfu/mL, and 8 ×10^8 cfu/mL following 24 hours of conventional culture. MAIN OUTCOME MEASURES: MTT colorimetric assay was utilized to determine the inhibitory rate of C6 glioma cells following treatment with various concentrations of PA-MSHA at different times. Cell apoptosis was detected by fluorescent microscopy following Hoechst 33258 staining. Flow cytometry was used to measure PA-MSHA effects on C6 cell cycle. RESULTS: Inhibitory rate of C6 glioma cells increased with prolonged time and increased dose. Hoechst 33258 staining revealed obvious morphological changes in apoptotic C6 glioma cells. Flow cytometry revealed hypodiploid peaks, Le., apoptotic peak, and the apoptotic rate in cells during S-phase significantly increased with increased concentrations in the experimental groups. CONCLUSION: With in vitro experiments, PA-MSHA preparations inhibited C6 glioma cell proliferation in a time- and dose-dependent manner. These mechanisms are likely associated with cell apoptosis induction and inhibition of the S phase.
基金supported by the National Key R&D Program of China(2020YFA0908000)the National Natural Science Foundation of China(82011530137,31961133007)+2 种基金Scientific and technological innovation project of CACMS(CI2023D002,CI2023E002)Key project at central government level:The ability to establish sustainable use of valuable Chinese medicine resources(2060302)Vetenskapsradet(2018-06003),Stiftelsen for internationalisering av hogre utbildning och forskning。
文摘Aporphine alkaloids have diverse pharmacological activities;however,our understanding of their biosynthesis is relatively limited.Previous studies have classified aporphine alkaloids into two categories based on the configuration and number of substituents of the D-ring and have proposed preliminary biosynthetic pathways for each category.In this study,we identified two specific cytochrome P450 enzymes(CYP80G6 and CYP80Q5)with distinct activities toward(S)-configured and(R)-configured substrates from the herbaceous perennial vine Stephania tetrandra,shedding light on the biosynthetic mechanisms and stereochemical features of these two aporphine alkaloid categories.Additionally,we characterized two CYP719C enzymes(CYP719C3 and CYP719C4)that catalyzed the formation of the methylenedioxy bridge,an essential pharmacophoric group,on the A-and D-rings,respectively,of aporphine alkaloids.Leveraging the functional characterization of these crucial cytochrome P450 enzymes,we reconstructed the biosynthetic pathways for the two types of aporphine alkaloids in budding yeast(Saccharomyces cerevisiae)for the de novo production of compounds such as(R)-glaziovine,(S)-glaziovine,and magnoflorine.This study provides key insight into the biosynthesis of aporphine alkaloids and lays a foundation for producing these valuable compounds through synthetic biology.
基金supported by the National Key R&D Program of China(2020YFA0908000)Scientific and technological innovation project of China Academy of Chinese Medical Sciences(CI2023D002,CI2023E002,CI2021A04110,CI2021B014)+1 种基金the National Natural Science Foundation of China(81822046)Key project at central government level:The ability to establish sustainable use of valuable Chinese medicine resources(2060302).
文摘Cytochrome P450 enzymes play a crucial role as catalysts in the biosynthesis of numerous plant natural products(PNPs).Enhancing the catalytic activity of P450s in host microorganisms is essential for the efficient production of PNPs through synthetic biology.In this study,we engineered Saccharomyces cerevisiae to optimize the microenvironment for boosting the activities of P450s,including coexpression with the redox partner genes,enhancing NADPH supply,expanding the endoplasmic reticulum(ER),strengthening heme biosynthesis,and regulating iron uptake.This created a platform for the efficient production 11,20-dihydroxyferruginol,a key intermediate of the bioactive compound tanshinones.The yield was enhanced by 42.1-fold through 24 effective genetic edits.The optimized strain produced up to 67.69±1.33 mg/L 11,20-dihydroxyferruginol in shake flasks.Our work represents a promising advancement toward constructing yeast cell factories containing P450s and paves the way for microbial biosynthesis of tanshinones in the future.
基金supported by the Shenzhen Science and Technology Program(Nos.JCYJ2022081 and 8102014029)the National Natural Science Foundation of China(No.62171458)the National Key Research and Development Program of China(No.2021YFB2802004)。
文摘Recently,there has been increased attention toward 3D imaging using single-pixel single-photon detection(also known as temporal data)due to its potential advantages in terms of cost and power efficiency.However,to eliminate the symmetry blur in the reconstructed images,a fixed background is required.This paper proposes a fusion-data-based 3D imaging method that utilizes a single-pixel single-photon detector and millimeter-wave radar to capture temporal histograms of a scene from multiple perspectives.Subsequently,the 3D information can be reconstructed from the one-dimensional fusion temporal data by using an artificial neural network.Both the simulation and experimental results demonstrate that our fusion method effectively eliminates symmetry blur and improves the quality of the reconstructed images.
基金supported by Shandong Provincial Natural Science Foundation,China(Nos.ZR2021ME046 and ZR2022ME179)Liaocheng University College Students Innovation and Entrepreneurship Training Program(No.2020205926).
文摘The polarized electric field inside piezoelectric materials has been proven to be a promising technique to boost photogenerated charge separation.Herein,a novel flexible SnFe_(2)O_(4)/ZnIn_(2)S_(4)/polyvinylidene fluoride((CH2CF2)_(n),PVDF)(P-SZ)film piezophotocatalyst was successfully synthesized by combining PVDF,an organic piezoelectric material,with a SnFe_(2)O_(4)/ZnIn_(2)S_(4)(SFO/ZIS)type II heterojunction photocatalyst.The hydrogen evolution rate of SFO/ZIS heterojunction with a SFO content of 5%is about 846.79μmol·h^(−1)·g^(−1),which is 3.6 times that of pristine ZIS.Furthermore,after being combined with PVDF,the optimum hydrogen evolution rate of P-SZ is about 1652.7μmol·h^(−1)·g^(−1)in the presence of ultrasound,which exceeds that of 5%SFO/ZIS by an approximate factor of 2.0.Based on experimental results,the mechanism of the improved photocatalytic performance of P-SZ was proposed on the basis of the piezoelectric field in PVDF and the formed heterojunction between SFO and ZIS,which effectively boosted the separation of photoinduced charges.This work provides an efficient strategy for multi-path collection and utilization of natural solar and vibrational energy to enhance photoactivity.
基金Supported by the National Natural Science Foundation of China(11925502,11935001,11961141003,11890714,12147101)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB34030000)the National Key R&D Program of China(2018YFA0404404)。
文摘Through systematic investigations using the axially deformed solutions of the Skyrme-Hartree-Fock-Bogoliubov equations with 132 sets of Skyrme interaction parameters,it is confirmed that the neutron-skin thickness(Sn)of a neutron-rich nucleus is proportional to the difference between the proton radii of mirror nuclei(R_(p)^(mir)).This indicates that Sn may be deduced from R_(p)^(mir).Compared with the results of the Skyrme-Hartree-Fock model,pairing effects are found to enhance the correlation for most mirror pairs,whereas deformation effects may weaken the correlation.Furthermore,the correlation between Sn and R_(p)^(mir) is studied for isotones with N=20 and N=28,which reveals a stronger linear correlation with increasing|N−Z|.This result demonstrates that it is possible to extract the neutron-skin thickness of an unstable nucleus from the proton radii difference of the mirror nuclei of its isotones.
基金the Basic Research Program of Shenzhen(No.JCYJ20170412171744267)。
文摘In this Let ter,a single scattering turbulence model in a narrow beam case for ultraviolet(UV)communication is proposed based on the division of the effective scattering volume.This model takes the variation of atmospheric scattering,absorption,and turbulence in different paths into account.Meanwhile,the applicable transceiver configurations of this model are provided by analyzing path loss error caused by the single scattering assumption in the UV channel.Furthermore,we investigate the effect of turbulence on the probability density function of the arriving power in both coplanar and non-coplanar scenarios.The averaging effect of multipath propagation on the arriving power's fluctuations is presented.Then,the bit-error-rate performance is also studied.This work provides an efficient way for UV turbulence channel estimation.
基金supported by the National Natural Science Foundation of China (81422053 and 81373906 to Wei Gao and 81325023 to Luqi Huang)the Support Project of High-level Teachers in Beijing Municipal Universities in the Period of 13th Five-year Plan (CIT&TCD20170324 to Wei Gao)the Key project at Central Government Level: The Ability Establishment of Sustainable Use for Valuable Chinese Medicine Resources (2060302 to Luqi Huang)
文摘Sterol C24-methyltransferase(SMT) plays multiple important roles in plant growth and development. SMT1, which belongs to the family of transferases and transforms cycloartenol into 24-methylene cycloartenol, is involved in the biosynthesis of 24-methyl sterols. Here, we report the cloning and characterization of a cDNA encoding a sterol C24-methyltransferase from Tripterygium wilfordii(Tw SMT1). Tw SMT1(Gen Bank access number KU885950) is a 1530 bp cDNA with a 1041 bp open reading frame predicted to encode a 346-amino acid, 38.62 k Da protein. The polypeptide encoded by the SMT1 cDNA was expressed and purified as a recombinant protein from Escherichia coli(E. coli) and showed SMT activity. The expression of Tw SMT1 was highly up-regulated in T. wilfordii cell suspension cultures treated with methyl jasmonate(Me JA). Tissue expression pattern analysis showed higher expression in the phellem layer compared to the other four organs(leaf, stem, xylem and phloem), which is about ten times that of the lowest expression in leaf. The results are meaningful for the study of sterolbiosynthesis of T. wilfordii and will further lay the foundations for the research in regulating both the content of other main compounds and growth and development of T. wilfordii.
基金supported by the National Natural Science Foundation of China(Nos.81422053 and 81373906 to Wei Gao,and No.81325023 to Luqi Huang)the National High Technology Research and Development Program of China(863 Program,No.2015AA0200908)
文摘The 4-hydroxy-3-methylbut-2-enyl diphosphate reductase(HDR) is the last step key enzyme of the methylerythritol phosphate(MEP) pathway,synthesizing isopentenyl diphosphate and its allyl isomer dimethylallyl diphosphate,which is important for regulation of isoprenoid biosynthesis.Here the full-length cDNA of HDR,designated TwHDR(GenBank Accession No.KJ933412.1),was isolated from Tripterygium wilfordii for the first time.TwHDR has an open reading frame(ORF) of 1386 bp encoding461 amino acids.TwHDR exhibits high homology with HDRs of other plants,with an N-terminal conserved domain and three conserved cysteine residues.TwHDR cDNA was cloned into an expression vector and transformed into an Escherichia coli hdr mutant.Since loss-of-function E.coli hdr mutant is lethal,the result showed that transformation of TwHDR cDNA rescued the E.coli hdr mutant.This complementation assay suggests that the TwHDR cDNA encodes a functional HDR enzyme.The expression of TwHDR was induced by methyl-jasmonate(MJ) in T.wilfordii suspension cells.The expression of TwHDR reached the highest level after 1 h of MJ treatment.These results indicate that we have identified a functional TwHDR enzyme,which may play a pivotal role in the biosynthesis of diterpenoid triptolide in T.wilfordii.
基金supported by the National Key R&D Program of China (No.2020YFA0908000)the Key Project at central government level: The ability establishment of sustainable use for valuable Chinese medicine resources (No.2060302-1806-03)Innovation Team and Talents Cultivation Program of National Administration of Traditional Chinese Medicine (ZYYCXTD-D202005)。
文摘Tripterygium wilfordii is a valuable medicinal plant rich in biologically active diterpenoids,but there are few studies on the origins of these diterpenoids in its secondary metabolism.Here,we identified three regions containing tandemly duplicated diterpene synthase genes on chromosomes(Chr) 17 and 21 of T. wilfordii and obtained 11 diterpene synthases with different functions.We farther revealed that these diterpene synthases underwent duplication and rearrangement at approximately 2.3-23.7 million years ago(MYA) by whole-genome triplication(WGT),transposon mediation,and tandem duplication,followed by functional divergence.We first demonstrated that four key amino acids in the sequences of TwCPS3,TwCPS5,and TwCPSS were altered during evolution,leading to their functional divergence and the formation of diterpene secondary metabolites.Then,we demonstrated that the functional divergence of three TwKSLs was driven by mutations in two key amino acids.Finally,we discovered the mechanisms of evolution and pseudogenization of miltiradiene synthases in T.wilfordii and elucidated that the new function in TwMS1/2 from the terpene synthase(TPS)-b subfamily was caused by progressive changes in multiple amino acids after the WGT event.Our results provide key evidence for the formation of diverse diterpenoids during the evolution of secondary metabolites in T.wilfordii.
基金supported by grants from the National Natural Science Foundation of China (91332119,81161120497,30925015,30830044,31371143,30900582 and 81221002)the National Basic Research Development Program from the Ministry of Science and Technology of China (2014CB542204)
文摘Dopamine D1 receptors(D1Rs) play a key role in cocaine addiction, and multiple protein kinases such as GRKs, PKA, and PKC are involved in their phosphorylation. Recently, we reported that protein kinase D1 phosphorylates the D1 R at S421 and promotes its membrane localization. Moreover, this phosphorylation of S421 is required for cocaineinduced behaviors in rats. In the present study, we generated transgenic mice over-expressing S421A-D1 R in the forebrain. These transgenic mice showed reduced phospho-D1R(S421) and its membrane localization, and reduced downstream ERK1/2 activation in the striatum. Importantly, acute and chronic cocaine-induced locomotor hyperactivity and conditioned place preference were significantly attenuated in these mice. These findings provide in vivo evidence for the critical role of S421 phosphorylation of the D1 R in its membrane localization and in cocaine-induced behaviors. Thus, S421 on the D1 R represents a potential pharmacotherapeutic target for cocaine addiction and other drug-abuse disorders.
基金National Key R&D Program of China(2020YFA0908000)CACMS Innovation Fund(CI2021A04109)+1 种基金the National Natural Science Foundation of China(81822046)Key project at central government level:The ability to establish sustainable use of valuable Chinese medicine resources(2060302).
文摘Borneol is a precious monoterpenoid with two chiral structures,(-)-borneol and(+)-borneol.Bornyl diphosphate synthase is the key enzyme in the borneol biosynthesis pathway.Many(+)-bornyl diphosphate synthases have been reported,but no(-)-bornyl diphosphate synthases have been identified.Blumea balsamifera leaves are rich in borneol,almost all of which is(-)-borneol.In this study,we identified a high-efficiency(-)-bornyl diphosphate synthase(BbTPS3)from B.balsamifera that converts geranyl diphosphate(GPP)to(-)-bornyl diphosphate,which is then converted to(-)-borneol after dephosphorylation in vitro.BbTPS3 exhibited a K m value of 4.93±1.38μM for GPP,and the corresponding k cat value was 1.49 s−1.Multiple strategies were applied to obtain a high-yielding(-)-borneol producing yeast strain.A codon-optimized BbTPS3 protein was introduced into the GPP high-yield strain MD,and the resulting MD-B1 strain produced 1.24 mg⋅L^(-1)(-)-borneol.After truncating the N-terminus of BbTPS3 and adding a Kozak sequence,the(-)-borneol yield was further improved by 4-fold to 4.87 mg⋅L^(-1).Moreover,the(-)-borneol yield was improved by expressing the fusion protein module of ERG20 F96W-N127W-YRSQI-t14-BbTPS3K2,resulting in a final yield of 12.68 mg⋅L^(-1) in shake flasks and 148.59 mg⋅L^(-1) in a 5-L bioreactor.This work is the first reported attempt to produce(-)-borneol by microbial fermentation.
文摘Objective: To clone and investigate two dehydrodolichyl diphosphate synthase genes of Tripterygium wilfordii by bioinformatics and tissue expression analysis. Materials and Methods: According to the T. wifordii transcriptome database, specific primers were designed to clone the TwDHDDS1 and TwDHDDS2 genes via PCR. Based on the cloned sequences, protein structure prediction, multiple sequence alignment and phylogenetic tree construction were performed. The expression levels of the genes in different tissues of T. wilfordii were measured by real?time quantitative PCR. Results: The TwDHDDS1 gene encompassed a 873 bp open reading frame(ORF) and encoded a protein of 290 amino acids. The calculated molecular weight of the translated protein was about 33.46 kDa, and the theoretical isoelectric point(pI) was 8.67. The TwDHDDS2 encompassed a 768 bp ORF, encoding a protein of 255 amino acids with a calculated molecular weight of about 21.19 kDa, and a theoretical isoelectric point(pI) of 7.72. Plant tissue expression analysis indicated that TwD HDDS1 and TwDHDDS2 both have relatively ubiquitous expression in all sampled organ tissues, but showed the highest transcription levels in the stems. Conclusions: The results of this study provide a basis for further functional studies of TwDHDDS1 and TwDHDDS2. Most importantly, these genes are promising genetic targets for the regulation of the biosynthetic pathways of important bioactive terpenoids such as triptolide.