纤维素/海藻酸钠/明胶复合水凝胶的制备与性能

纤维素作为一种来源丰富的天然高分子材料,具有优异的生物相容性和可降解性,但其难溶特性限制了其应用。文中采用离子液体1-烯丙基-3-甲基咪唑氯化物(AmimCl)溶解纤维素(Cel),海藻酸钠(SA)与明胶(Gel)混合水溶液作为凝固浴进行纤维素再生,进一步通过浸泡氯化钙(CaCl_(2))溶液交联海藻酸钠,制备了一种透明、高强度的复合水凝胶。分别探究了纤维素浓度(3%,4%,5%,6%,7%和8%)及不同的海藻酸钠/明胶质量比(0:10,2:8,4:6,6:4,8:2和10:0)对水凝胶性能的影响。利用傅里叶变换红外光谱、扫描电子显微镜、X射线衍射仪、紫外可见分光光度计和万能材料试验机对水凝胶进行了表征。结果表明,水凝胶中各组分之间的氢键作用及海藻酸钠与Ca^(2+)之间的离子相互作用赋予水凝胶优异的力学性能,相比于纯水作为凝固浴制备的再生纤维素水凝胶,强度提高了26.36%。随着纤维素浓度的增加,水凝胶的结晶度和网络结构的致密性增加,水凝胶的力学性能显著提升。此外,海藻酸钠/明胶的比例也对水凝胶的力学性能有显著影响,当海藻酸钠与明胶质量比为6:4时,水凝胶力学性能最好,最高达到2.349 MPa。生物降解性分析表明,水凝胶具有良好的生物降解性,在食品包装和生物医药领域具有潜在应用价值。

分析化学课程思政建设的举措

为全面推进课程思政建设,实施教学改革势在必行。本文基于分析化学学科特点以及课程培养目标,从提高教师思政教育能力、构建课程思政体系、深挖分析化学课程思政元素、优化教学评价四个方面出发,提出了全面推进分析化学课程思政建设的一些举措,以促进课程思政有效融入课堂。将思政教育与专业知识进行融合,有利于学生在掌握分析化学理论知识和操作技能的同时,培养以爱国主义为核心的民族精神和以改革创新为核心的时代精神,树立唯物主义的辩证思维、严谨认真和求真务实的科学态度、科学发展观等,形成广泛的课程思政理念共识并深入人心,从而实现教书与育人、立德与树人的有机统一。

An integrated north–south paleo-Dadu-Anning River: New insights from bulk major and trace element analyses of the Xigeda Formation

The Xianshuihe-Anninghe fault extends SE–S and constitutes the southeastern margin of the Tibetan Plateau.However,the Dadu River which is associated with the fault does not flow following the path,but makes a 90ºturn within a distance of 1 km at Shimian,heading east,and joins the Yangtze River,finally flowing into the East China Sea.Adjacent to the abrupt turn,a low and wide pass near the Daqiao reservoir at Mianning separates the N–S course of the Dadu River from the headwater of the Anning River which then flows south into the Yunnan Province along the Anninghe fault.Therefore,many previous studies assumed southward flow of the paleo-Dadu River from the Shimian to the Anning River.However,evidences for the capture of the integrated N–S paleo-Dadu-Anning River,its timing,and causes are still insufficient.This study explored the paleo-drainage pattern of the Dadu and Anning Rivers based on bulk mineral and geochemical analyses of the large quantities of fluvial/lacustrine sediments along the trunk of the Dadu and Anning Rivers.Similar with sands in the modern Dadu River,the Xigeda sediments also exhibit a granitoid affinity with the bulk major mineral compositions of quartz(>50%),anorthite(about 10%),orthoclase(about 5%),muscovite(about 5%),and clinochlore(about 4%).Correspondingly,bulk major elements show high SiO_(2),with all samples>60%,and some of them>70%,low TiO_(2)(≤0.75%),P_(2)O_(5)(≤0.55%),FeO*(≤5%),and relatively high CaO(1.02%–8.51%),Na_(2)O(1.60%–2.52%),and K_(2)O(2.17%–2.71%),with a uniform REE patterns.Therefore,synthesizing all these results indicate that these lacustrine sediments have similar material sources,which are mainly derived from its course in the Songpan-Ganzi flysch block,implying that the paleo-Dadu originally flowed southward into the Anning River and provided materials to the Xigeda ancient lake.The rearrangement of the paleo-Dadu River appears to be closely related to the locally focused uplift driven by strong activities of the XianshuiheXiaojiang fault system.

Silencing transformer and transformer-2 in Zeugodacus cucurbitae causes defective sex determination with inviability of most pseudomales

transformer is a switch gene for sex determination in many insects, which cooperates with transformer-2 that is expressed in both sexes to regulate female differentiation, particularly in dipterans. Zeugodacus cucurbitae(Coquillett) is a very destructive pest worldwide, however, its sex determination pathway remains largely uncharacterized. Here, we show that the female sex ratio is sharply reduced with knockdown of either transformer or transformer-2 by RNA interference in early embryos of Z. cucurbitae. Most of the males grown from the embryos with transient transformer and transformer-2 suppression mated with wild-type females and produced mixed sex progeny, with one exception that produced only female progeny, and all of the few remaining males failed to mate with wild-type females and produced no progeny. The exceptional male and those males with mating failure were XX pseudomales as determined by the detection of Y chromosome-linked Maleness-on-the-Y, indicating that most XX pseudomales are not viable. The phenotypes of transformer and transformer-2 suggest that they play a key role in regulating sex determination and are required for female sexual development of Z. cucurbitae. Our results will be beneficial to the understanding of sex determination in Z. cucurbitae and can facilitate the development of genetic sexing strains for its biological control.

A low-profile metamaterial absorber with ultrawideband reflectionless and wide-angular stability

An ultrawideband reflectionless metamaterial absorber(MA)is proposed by replacing the metallic ground with the complementary split-ring resonator(CSRR)structure.The proposed MA exhibits-10 d B reflectivity spectrum from 1 GHz to 20 GHz,which maintains more than 90%absorption from 1.5 GHz to20 GHz.Furthermore,it achieves angle stability for TE and TM polarization at oblique incident angles up to 40°and 65°,respectively.To achieve broadband absorption spectrum,we have adopted a single-layer high-impedance surface(HIS)loaded with a double-layer magnetic material(MM)structure.To further realize the RCS reduction into a lower frequency range,we have employed the scattering cancellation technology into the traditional metallic ground.Finally,we have fabricated a sample exhibiting the 10 d B RCS reduction from 1 GHz to 20 GHz with a thickness of 10 mm.Measurement and simulation results confirm that the proposed MA exhibits excellent comprehensive performance,making it suitable for many practical applications.

Emerging mechanisms and implications of c GAS-STING signaling in cancer immunotherapy strategies

The intricate interplay between the human immune system and cancer development underscores the central role of immunotherapy in cancer treatment.Within this landscape,the innate immune system,a critical sentinel protecting against tumor incursion,is a key player.The cyclic GMP-AMP synthase(c GAS)and stimulator of interferon genes(STING)pathway has been found to be a linchpin of innate immunity:activation of this signaling pathway orchestrates the production of type I interferon(IFN-α/β),thus fostering the maturation,differentiation,and mobilization of immune effectors in the tumor microenvironment.Furthermore,STING activation facilitates the release and presentation of tumor antigens,and therefore is an attractive target for cancer immunotherapy.Current strategies to activate the STING pathway,including use of pharmacological agonists,have made substantial advancements,particularly when combined with immune checkpoint inhibitors.These approaches have shown promise in preclinical and clinical settings,by enhancing patient survival rates.This review describes the evolving understanding of the c GAS-STING pathway's involvement in tumor biology and therapy.Moreover,this review explores classical and non-classical STING agonists,providing insights into their mechanisms of action and potential for optimizing immunotherapy strategies.Despite challenges and complexities,the c GAS-STING pathway,a promising avenue for enhancing cancer treatment efficacy,has the potential to revolutionize patient outcomes.

Modification of streamer-to-leader transition model based on radial thermal expansion in the sphere-plane gap discharge at high altitude

Historically,streamer-to-leader transition studies mainly focused on the rod-plane gap and low altitude analysis,with limited attention paid to the sphere-plane gap at high altitude analysis.In this work,sphere-plane gap discharge tests were carried out under the gap distance of 5 m at the Qinghai Ultra High Voltage(UHV)test base at an altitude of 2200 m.The experiments measured the physical parameters such as the discharge current,electric field intensity and instantaneous optical power.The duration of the dark period and the critical charge of streamer-toleader transition were obtained at high altitude.Based on radial thermal expansion of the streamer stem,we established a modified streamer-to-leader transition model of the sphere-plane gap discharge at high altitude,and calculated the stem temperature,stem radii and the duration of streamer-to-leader transition.Compared with the measured duration of sphere-plane electrode discharge at an altitude of 2200 m,the error rate of the modified model was 0.94%,while the classical model was 6.97%,demonstrating the effectiveness of the modified model.From the comparisons and analysis,several suggestions are proposed to improve the numerical model for further quantitative investigations of the leader inception.

Study on the low mechanical anisotropy of extruded Mg-Zn-Mn-Ce-Ca alloy tube in the compression process

In this study,the extruded Mg-Zn-Mn-Ce-Ca alloy tube with a low compression anisotropy along the ED,45ED and TD was prepared.The effect of the second phases,initial texture and deformation behavior on this low mechanical anisotropy was investigated.The results revealed that the alloy tube contains the high content(Mg1-xZnx)11Ce phase and the low content of Mg12Ce phase.These second phases are respectively incoherent and coherent with the Mg matrix,and their influence can be ignored.Additionally,the alloy tube exhibited a weak basal fiber texture,where the c-axis was aligned along the 0°∼30°tilt from TD to ED.Such a texture made the initial deformation(at 1.0%∼1.6%strain)of the three samples controlled by comparable basalslip.As deformation progressed(1.6∼9.0%strain),larger amounts of ETWs nucleated and gradually approached saturation in the three samples,re-orienting the c-axis to a 0°∼±30°deviation with respect to the loading directions.Meanwhile,the prismatic and pyramidal<c+a>slips replaced the dominant deformation progressively until fracture.Eventually,the similar deformation mechanisms determined by the weak initial texture in the three samples contribute to the comparable strain hardening rates,resulting in the low compressive anisotropy of the alloy tube.

Impact of frailty on short-term postoperative outcomes in patients undergoing colorectal cancer surgery:A systematic review and meta-analysis

BACKGROUND Colorectal cancer is a major global health challenge that predominantly affects older people.Surgical management,despite advancements,requires careful consideration of preoperative patient status for optimal outcomes.AIM To summarize existing evidence on the association of frailty with short-term postoperative outcomes in patients undergoing colorectal cancer surgery.METHODS A literature search was conducted using PubMed,EMBASE and Scopus databases for observational studies in adult patients aged≥18 years undergoing planned or elective colorectal surgery for primary carcinoma and/or secondary metastasis.Only studies that conducted frailty assessment using recognized frailty assess-ment tools and had a comparator group,comprising nonfrail patients,were included.Pooled effect sizes were reported as weighted mean difference or relative risk(RR)with 95%confidence intervals(CIs).RESULTS A total of 24 studies were included.Compared with nonfrail patients,frailty was associated with an increased risk of mortality at 30 d(RR:1.99,95%CI:1.47-2.69),at 90 d(RR:4.76,95%CI:1.56-14.6)and at 1 year(RR:5.73,95%CI:2.74-12.0)of follow up.Frail patients had an increased risk of any complications(RR:1.81,95%CI:1.57-2.10)as well as major complications(Clavien-Dindo classification grade≥III)(RR:2.87,95%CI:1.65-4.99)compared with the control group.The risk of reoperation(RR:1.18,95%CI:1.07-1.31),readmission(RR:1.70,95%CI:1.36-2.12),need for blood transfusion(RR:1.67,95%CI:1.52-1.85),wound complications(RR:1.49,95%CI:1.11-1.99),delirium(RR:4.60,95%CI:2.31-9.16),risk of prolonged hospitalization(RR:2.09,95%CI:1.22-3.60)and discharge to a skilled nursing facility or rehabilitation center(RR:3.19,95%CI:2.0-5.08)was all higher in frail patients.CONCLUSION Frailty in colorectal cancer surgery patients was associated with more complications,longer hospital stays,higher reoperation risk,and increased mortality.Integrating frailty assessment appears crucial for tailored surgical management.

Mechanism of Wendan decoction in preventing obesity by regulating multiple signal pathway networks based on gene promoter methylation

Objective:To investigate the potential mechanism of Wendan decoction in obesity by screening target genes with promoter region methylation changes and constructing a multiple signaling pathways network based on promoter methylation.Methods:The methylation degree of Itgad,Col8a1,Adra2b,Jund,Rab2a,Wnt8b,Fzd9,B4galt7,Pik3cd,Creb1,Stard8,and Mmp1 in the abdominal adipose tissue of obese rats was determined using the Agena MassARRAY system.Western blot was performed to assess protein expression levels.Target genes were identified based on the methylation degree in the promoter region and protein expression.Enrichment analysis of signaling pathways was conducted to identify relevant target genes and obtain a multiple signaling pathway network associated with obesity.Core and terminal effector molecules in the pathway networks were selected as research targets for reverse transcription-polymerase chain reaction(RT-PCR)analysis.Results:Four genes(Adra2b,Creb1,Itgad,and Pik3cd)showed a degree of promoter methylation consistent with their respective protein expression levels.Among them,Adra2b,Creb1,and Pik3cd expression increased,while that of Itgad decreased.Enrichment analysis revealed that Creb1 and Pik3cd were involved in 6 signaling pathways related to obesity:tumor necrosis factor(TNF)signaling pathway,growth hormone synthesis/secretion and action,adenosine 5'-monophosphate-activated protein kinase(AMPK)signaling pathway,relaxin signaling pathway,cyclic nucleotide(cAMP)signaling pathway,and phosphatidylinositol 3-kinase/protein kinase B(PI3K/Akt)signaling pathway.Subsequently,a multiple signaling pathways network was constructed based on promoter methylation.Key molecules including protein kinase B(AKT),mechanistic target of rapamycin complex 1(mTORC1),and unc-51 like autophagy activating kinase 1(ULK1),as well as terminal effector molecules interleukin-1β(IL-1β),interleukin-6(IL-6),and chemokine(C-X-C motif)ligand 2(CXCL2)were selected as research targets.Wendan decoction decreased the expressions of AKT,mTORC1,IL-1β,IL-6,and CXCL2 while up-regulating ULK1 expression.Conclusion:The mechanism of Wendan decoction in preventing obesity involves the regulation of multiple signaling pathways through the control of Creb1 and Pik3cd gene promoter methylation.However,the associated multi-path gene regulation mechanism in preventing obesity is complex.Thus,further exploration is needed to elucidate the role of methylation changes in this mechanism.

Comparison study on measurement of rail weld joint between inertial reference method and multi-point chord reference method

Purpose – Straightness measurement of rail weld joint is of essential importance to railway maintenance. Dueto the lack of efficient measurement equipment, there has been limited in-depth research on rail weld joint with a5-m wavelength range, leaving a significant knowledge gap in this field.Design/methodology/approach – In this study, the authors used the well-established inertial referencemethod (IR-method), and the state-of-the-art multi-point chord reference method (MCR-method). Two methodshave been applied in different types of rail straightness measurement trollies, respectively. These instrumentswere tested in a high-speed rail section within a certain region of China. The test results were ultimatelyvalidated through using traditional straightedge and feeler gauge methods as reference data to evaluate the railweld joint straightness within the 5-m wavelength range.Findings – The research reveals that IR-method and MCR-method produce reasonably similar measurementresults for wavelengths below 1 m. However, MCR-method outperforms IR-method in terms of accuracy forwavelengths exceeding 3 m. Furthermore, it was observed that IR-method, while operating at a slower speed,carries the risk of derailing and is incapable of detecting rail weld joints and low joints within the track.Originality/value – The research compare two methods’ measurement effects in a longer wavelength rangeand demonstrate the superiority of MCR-method.

A critical review of wheel/rail high frequency vibration-induced vibration fatigue of railway bogie in China

Purpose–This review aims to give a critical view of the wheel/rail high frequency vibration-induced vibration fatigue in railway bogie.Design/methodology/approach–Vibration fatigue of railway bogie arising from the wheel/rail high frequency vibration has become the main concern of railway operators.Previous reviews usually focused on the formation mechanism of wheel/rail high frequency vibration.This paper thus gives a critical review of the vibration fatigue of railway bogie owing to the short-pitch irregularities-induced high frequency vibration,including a brief introduction of short-pitch irregularities,associated high frequency vibration in railway bogie,typical vibration fatigue failure cases of railway bogie and methodologies used for the assessment of vibration fatigue and research gaps.Findings–The results showed that the resulting excitation frequencies of short-pitch irregularity vary substantially due to different track types and formation mechanisms.The axle box-mounted components are much more vulnerable to vibration fatigue compared with other components.The wheel polygonal wear and rail corrugation-induced high frequency vibration is the main driving force of fatigue failure,and the fatigue crack usually initiates from the defect of the weld seam.Vibration spectrum for attachments of railway bogie defined in the standard underestimates the vibration level arising from the short-pitch irregularities.The current investigations on vibration fatigue mainly focus on the methods to improve the accuracy of fatigue damage assessment,and a systematical design method for vibration fatigue remains a huge gap to improve the survival probability when the rail vehicle is subjected to vibration fatigue.Originality/value–The research can facilitate the development of a new methodology to improve the fatigue life of railway vehicles when subjected to wheel/rail high frequency vibration.

Synergistic cerium doping and MXene coupling in layered double hydroxides as efficient electrocatalysts for oxygen evolution

Oxygen evolution reaction(OER) is a bottle-neck process in many sustainable energy conversion systems due to its sluggish kinetics.The development of cost-effective yet efficient electrocatalysts towards OER is highly desirable but still a great challenge at current stage.Herein,a new type of hybrid nanostructure,consisting of two-dimensional(2D) Cerium-doped NiFe-layered double hydroxide nanoflakes directly grown on the 2D Ti3C2Tx MXene surface(denoted as NiFeCe-LDH/MXene),is designed using a facile insitu coprecipitation method.The resultant NiFeCe-LDH/MXene hybrid presents a hierarchical nanoporous structure,high electrical conductivity and strong interfacial junction because of the synergistic effect of Ce doping and MXene coupling.As a result,the hybrid catalyst exhibits an excellent catalytic activity for OER,delivering a low onset overpotential of 197 mV and an overpotential of 260 mV at a current density of 10 mA·cm-2 in the alkaline medium,much lower than its pure LDH counterparts and IrO2 catalyst.Besides,the hybrid catalyst also displays a fast reaction kinetics and a remarkable stable durability.Further theoretic studies using density function theory(DFT) methods reveal that Ce doping could effectively narrow the bandgap of NiFe-LDH and reduce the overpotential in OER process.This work may shed light on the exploration of advanced electrocatalysts for renewable energy conversion and storage systems.

Integrated multi-omics analysis of developing‘Newhall’orange and its glossy mutant provide insights into citrus fragrance formation

Sesquiterpene valencene is dominant in flavedo tissues of sweet oranges and imparts a unique woody aroma.However,the interaction between the biosynthetic pathways of valencene and other nutritional compounds is less studied.Sesquiterpenoids were significantly accumulated in a previously reported glossy mutant of orange(MT)than the wild type(WT),especially valencene and caryophyllene.In addition,we identified several other pathways with variations at both the transcriptional and metabolic levels in MT.It’s interesting to found those upregulated metabolites in MT,such as eukaryotic lipids,kaempferol and proline also showed strong positive correlation with valencene along with fruit maturation while those down-regulated metabolites,such as phenylpropanoid coumarins and most of the modified flavonoids exhibited negative correlation.We then categorized these shifted pathways into the‘sesquitepenoid-identical shunt’and the sesquitepenoid-opposite shunt’and confirmed the classification result at transcriptional level.Our results provide important insights into the connections between various fruit quality-related properties.

Research Progress on Acupuncture Therapy in Infertility: A Bibliometric Analysis from 2000 to 2021

Objective: To investigate the research progress and new trend of acupuncture in the treatment of infertility from 2000 to 2021. Methods: The literature review was conducted on acupuncture and moxibustion treatment of infertility from 2000 to 2021 from the Web of Science core collection and PubMed. CiteSpace and VOSviewer were used to analyze the annual number of articles, countries, institutions, authors, journals, references and keywords. Statistical Analysis Toolkit for Informetrics 3.2 (SATI) and IBM SPSS Modeler 18.0 were employed to draw the maps of core acupoints and acupuncture approaches. Results: A total of 316 articles were included. From 2000 to 2021 the number of publications has been ever increased with certain fluctuations. The United States was the most productive country. Heilongjiang University of Chinese Medicine was the most active institution. Stener-Victorin E was the highest cited author. Fertility and Sterility was the most prolific journal. Paulus We, 2002 was the highest co-citation literature. SP6 (Sanyinjiao) was the most commonly used acupoint. Manual acupuncture was the most commonly used method. Conclusions: The study of acupuncture in the treatment of infertility is characterized by multinational, multi-institutional participation and close regional cooperation. Acupuncture is a potentially effective therapy for infertility. Due to a lack of research quality and difficulties in performing double-blind, high-quality clinical evidence is urgently required. A complete acupuncture therapy system for infertility should be gradually constructed.

Stability analysis of backflling in subsiding area and optimization of the stoping sequence

In underground mining by sublevel caving method, the deformation and damage of the surface induced by subsidence are the major challenging issues. The dynamic and soft backflling body increases the safety risks in the subsiding area. In this paper, taking Zhangfushan iron mine as an example, the ore body and the general layout are focused on the safety of backflling of mined-out area. Then, we use the ANSYS software to construct a three-dimensional(3D) model for the mining area in the Zhangfushan iron mine. According to the simulation results of the initial mining stages, the ore body is stoped step by step as suggested in the design. The stability of the backflling is back analyzed based on the monitored displacements, considering the stress distribution to optimize the stoping sequence. The simulations show that a reasonable stoping sequence can minimize the concentration of high compressive stress and ensure the safety of stoping of the ore body.

Nonclinical Study of the Active Components of Doxorubicin Hydrochloride Liposome Injection in Vivo

Objectives: A non-clinical study was performed to establish a LC-MS/MS method to determine the in vivo active components of doxorubicin hydrochloride liposome injection in the plasma of Sprague-Dawley rats. Methods: Ten male SD rats were administered tail vein with a single dose of 10 mg/kg, and the concentrations of doxorubicin hydrochloride in plasma, heart, liver, spleen, lung, and kidney were determined by liquid chromatography-tandem mass spectrometry, and the pharmacokinetic parameters were calculated. Results: The final concentration of doxorubicin hydrochloride ranged from 500 ng/mL to 250,000 ng/mL, and the lower limit of quantification was 500 ng/mL;the main pharmacokinetic parameters: T1/2 was (19.282 ± 10.305) h, Cmax was (118514.828 ± 26155.134) ng/mL, AUC0-24 and AUC0-∞ were (1216659.205 ± 192706.268) ng/mL⋅h and (2082244.523 ± 860139.487) ng/mL⋅h, MRT0-24 and MRT0-∞ were (9.237 ± 0.423) h and (26.52 ± 14.015) h, respectively, and clearance (CL) was (0.005 ± 0.002) mL/h⋅ng. Conclusions: The method is simple, rapid, and sensitive, which can be used for the determination of doxorubicin hydrochloride concentration in the plasma of SD rats and pharmacokinetic non-clinical studies.

食管鳞癌患者根治性放疗预后列线图模型的构建—泛京津冀多中心回顾分析(3JECROG R-03A)

目的:构建列线图(nomogram)模型以预测食管鳞癌患者的预后情况,指导个体化治疗。方法:回顾性分析2002年1月至2016年12月国内10家放疗中心(泛京津冀食管癌协作组-3JECROG)收治的2680例根治性放疗食管鳞癌患者资料,随机分为训练组和验证组,根据训练组的预后因素构建nomogram模型,并进行训练组内部和验证组外部验证。分别以nomogram模型与AJCC/UICC分期评估两组患者预后及临床获益。结果:全组1、3、5年生存率分别为69.0%、37.7%、31.0%。多因素分析肿瘤部位、TNM分期、原发肿瘤体积和是否同步化疗是影响食管癌的独立预后因素(均P<0.05)。在训练组和验证组中nomogram模型的一致性指数(C-index)、AUC值均高于AJCC/UICC分期(均P<0.001)。基于nomogram模型分为低、中、高风险亚组与AJCC/UICC分期比较,nomogram模型的生存曲线之间具有显著性差异(P<0.001),且1、3、5年的总生存临床决策曲线(decision curve analysis,DCA)下面积均具有显著性差异。结论:本研究构建的nomogram模型较AJCC/UICC分期具有更好的预测能力,有助于食管癌患者的预后判断及指导个体化治疗。

Mapping QTL affecting the vertical distribution and seed set of soybean [Glycine max(L.) Merr.] pods

Number of pods per plant and number of seeds per pod are quantitative,multigenic traits and important components of yield in soybean[Glycine max(L.)Merr.].Pods are distributed unevenly in the upper,middle,and lower segments of the plant and this distribution is affected by sowing date(SD).A population of four-way recombinant inbred lines(FW-RIL),containing 160 F2:8 individuals,was generated from the cross(Kenfeng 14×Kenfeng 15)×(Heinong 48×Kenfeng 19).A linkage map consisting of 275 simple sequence repeat(SSR)markers was used to map quantitative trait loci(QTL)associated with the production of one,two,three,and four seeds per pod in the upper,middle,and lower segments of plants at two SDs,totaling 12 measurements per SD.A wide range of variation in the twelve characteristics was observed among the four parental lines and the FW-RIL population at the two SDs.The effect of SD2(May 17,2016)on pod number was stronger than that of SD1(May 7,2016)because the heritability of each trait in the SD1 experiment was generally greater than that of SD2.The study identified 76 QTL controlling pod number,with the phenotypic variation explained by each QTL ranging from 1.86%to 13.71%.The numbers of QTL controlling one,two,three,and four seeds per pod were 28,23,23,and 23,respectively.There were 30,28,and 28 QTL controlling the pod number in the upper,middle,and lower segments of the plant,respectively.Forty-five QTL were identified at SD1 and 38 QTL were identified at SD2.Seventeen QTL were associated with pod-number traits.The QTL qPNA1–3 was associated with the number of pods containing one seed in the middle segment of the plant at both SDs.Sixty-three QTL were published QTL(common areas existed when integrating on a map GmComposite2003 of Wm82 based on left and right markers).and 13 QTL related to pod number were newly discovered.These results provide a reference for breeders to improve soybean yield by combining advantageous alleles for these QTL.Future studies may reveal candidate genes for these QTL and identify causal alleles for markerassisted selection.

INFLUENCE OF DOPING COMPONENT ON THE SOL-GEL PROCESS

Si-29 and Li-7 NMR have been used to study the sol-gel process. It has been found that the doping components (such as TlNO3, LiNO2, and Cd(NO3)(2)) could promote the hydrolysis and condensation reactions and their ratio, thus they could influence the gelation time. The lithium species has been demonstrated to remain as free hydration. ions during the whole sot-gel process and not to participate in forming the inorganic network.