精益创业过程中企业与用户的价值共创机理——基于互动视角的探索性单案例研究

精益创业强调敏捷应对市场需求变化并持续为顾客创造价值,是兼具理论前沿和实践价值的新兴话题。但现有精益创业过程研究缺乏对企业和用户价值共创行为的深入探讨。本文以乐纯公司为研究对象,从互动视角探究精益创业过程中企业与用户的价值共创机理并发现:第一,精益创业过程中企业与用户的价值共创经历企业主导、企业用户协同和用户主导三个阶段,在各阶段的概念、开发—产品—测量—数据和认知环节分别通过价值识别、价值创造和价值迭代实现价值共创;第二,用户与企业的共创模式呈现被动参与式共创—主动体验式共创—创新驱动式共创的阶段性演变,用户参与程度不断增强、主导地位不断上升;第三,阶段演化过程中互动关系发生根本性改变:企业角色由信息寻求者转变为解决方案提供者,用户角色从信息来源方转变为产品创新者。本文通过勾勒精益创业过程中企业与用户的互动行为规律以揭示两者价值共创的机理,为精益创业和价值共创实践提供有益启发。

Interface Engineering of Titanium Nitride Nanotube Composites for Excellent Microwave Absorption at Elevated Temperature

Currently,the microwave absorbers usually suffer dreadful electromagnetic wave absorption(EMWA)performance damping at elevated temperature due to impedance mismatching induced by increased conduction loss.Consequently,the development of high-performance EMWA materials with good impedance matching and strong loss ability in wide temperature spectrum has emerged as a top priority.Herein,due to the high melting point,good electrical conductivity,excellent environmental stability,EM coupling effect,and abundant interfaces of titanium nitride(TiN)nanotubes,they were designed based on the controlling kinetic diffusion procedure and Ostwald ripening process.Benefiting from boosted heterogeneous interfaces between TiN nanotubes and polydimethylsiloxane(PDMS),enhanced polarization loss relaxations were created,which could not only improve the depletion efficiency of EMWA,but also contribute to the optimized impedance matching at elevated temperature.Therefore,the TiN nanotubes/PDMS composite showed excellent EMWA performances at varied temperature(298-573 K),while achieved an effective absorption bandwidth(EAB)value of 3.23 GHz and a minimum reflection loss(RLmin)value of−44.15 dB at 423 K.This study not only clarifies the relationship between dielectric loss capacity(conduction loss and polarization loss)and temperature,but also breaks new ground for EM absorbers in wide temperature spectrum based on interface engineering.

Highly Flexible Graphene-Film-Based Rectenna for Wireless Energy Harvesting

Herein,we report the design,fabrication,and performance of two wireless energy harvesting devices based on highly flexible graphene macroscopic films(FGMFs).We first demonstrate that benefiting from the high conductivity of up to 1×10^(6)S m^(-1)and good resistive stability of FGMFs even under extensive bending,the FGMFs-based rectifying circuit(GRC)exhibits good flexibility and RF-to-DC efficiency of 53%at 2.1 GHz.Moreover,we further expand the application of FGMFs to a flexible wideband monopole rectenna and a 2.45 GHz wearable rectenna for harvesting wireless energy.The wideband rectenna at various bending conditions produces a maximum conversion efficiency of 52%,46%,and 44%at the 5th Generation(5G)2.1 GHz,Industrial Long-Term Evolution(LTE)2.3 GHz,and Scientific Medical(ISM)2.45 GHz,respectively.A 2.45 GHz GRC is optimized and integrated with an AMC-backed wearable antenna.The proposed 2.45 GHz wearable rectenna shows a maximum conversion efficiency of 55.7%.All the results indicate that the highly flexible graphene-film-based rectennas have great potential as a wireless power supplier for smart Internet of Things(loT)applications.

Insight into structure evolution of carbon nitrides and its energy conversion as luminescence

A series of carbon nitride(CN)materials represented by graphitic carbon nitride(g-C_(3)N_(4))have been widely used in bioimaging,biosensing,and other fields in recent years due to their nontoxicity,low cost,and high luminescent quantum efficiency.What is more attractive is that the luminescent properties such as wavelength and intensity can be regulated by controlling the structure at the molecular level.Hence,it is time to summarize the related research on CN structural evolution and make a prospect on future developments.In this review,we first summarize the research history and multiple structural evolution of CN.Then,the progress of improving the luminescence performance of CN through structural evolution was discussed.Significantly,the relationship between CN structure evolution and energy conversion in the forms of photoluminescence,chemiluminescence,and electrochemiluminescence was reviewed.Finally,key challenges and opportunities such as nanoscale dispersion strategy,luminous efficiency improving methods,standardization evaluation,and macroscopic preparation of CN are highlighted.

Evaluation of the Clinical Efficacy of Full Femtosecond Laser Surgery in the Treatment of Myopia

Objective:To evaluate the clinical effect of full femtosecond laser surgery in the treatment of myopia patients.Methods:120 myopia patients admitted to our hospital from January 2022 to June 2023 were selected.According to the random number table method,60 patients in the observation group underwent full femtosecond laser surgery,and 60 patients in the control group underwent femtosecond laser-assisted in situ keratomileusis(FS-LASIK)surgery.The clinical effects of the two groups were compared.Results:10 days postoperatively and 6 months after operation,the visual acuity level of the observation group was higher than that of the control group,the postoperative corneal asphericity coefficient and corneal full-thickness were lower than those of the control group,and the total effective rate 6 months after operation was higher than that of the control group(P<0.05).Conclusion:Full femtosecond laser surgical treatment can improve the postoperative visual acuity of patients with myopia,enhance the corneal asphericity coefficient(Q)and corneal full-thickness,and exert significant clinical effects.

Computational fluid dynamics-discrete element method simulation of stirred tank reactor for graphene production

Liquid phase exfoliation(LPE)process for graphene production is usually carried out in stirred tank reactor and the interactions between the solvent and the graphite particles are important as to improve the production efficiency.In this paper,these interactions were revealed by computational fluid dynamics–discrete element method(CFD-DEM)method.Based on simulation results,both liquid phase flow hydrodynamics and particle motion behavior have been analyzed,which gave the general information of the multiphase flow behavior inside the stirred tank reactor as to graphene production.By calculating the threshold at the beginning of graphite exfoliation process,the shear force from the slip velocity was determined as the active force.These results can support the optimization of the graphene production process.

Analysis of the Efficacy of Triamcinolone Acetonide Combined with Ranibizumab in the Treatment of Fundus Diseases

Objective:To analyze the effect of triamcinolone acetonide combined with ranibizumab in patients with fundus diseases.Methods:100 patients with fundus diseases admitted from January 2018 to January 2023 were selected.The patients were separated into two groups according to the random number table method,with 50 cases in the control group(treated with ranibizumab),and 50 cases in the observation group(treated with triamcinolone acetonide combined with ranibizumab).The clinical effects of both treatment regimens were compared.Results:The time taken for symptom disappearance of the observation group was shorter than that of the control group(P<0.05).The observation group had higher naked-eye visual acuity(4.18±0.89)compared to the control group.Besides,the observation group also had lower intraocular pressure(14.19±1.33 mmHg)and retinal thickness(283.14±3.29μm),with(P<0.05)compared to the control group.Moreover,the observation group had a lower adverse reaction rate and a higher quality of life(P<0.05).Conclusion:The application of triamcinolone acetonide combined with ranibizumab treatment can quickly relieve the clinical symptoms of patients with fundus disease,improve visual acuity,intraocular pressure,and retinal thickness,with low adverse reaction rate and better prognosis and quality of life.

高通量测序分析PIK3CA突变型与野生型结直肠癌的肠道菌群特征

目的:采用16S rDNA二代高通量测序技术,研究PIK3CA突变型与野生型结直肠癌患者中的肠道菌群特征。方法:选取2016年12月至2017年12月华中科技大学同济医学院附属协和医院结直肠癌患者19例,采用16S rDNA高通量测序技术分析PIK3CA突变型(n=4)和PIK3CA野生型(n=15)之间肿瘤组织中微生物多样性和组成差异。结果:在门水平上,结直肠癌患者的肠道菌群主要由变形菌门、栖热菌门、放线菌门、厚壁菌门和拟杆菌门组成,占总群落的98%以上。Alpha多样性分析显示,PIK3CA突变型与野生型结直肠癌患者之间微生物多样性有显著性差异,且PIK3CA突变型患者中微生物多样性明显高于野生型。Beta多样性分析显示PIK3CA突变型与野生型结直肠癌患者的肿瘤微生物特征有显著性差异。Spearman关联网络分析结果显示,在PIK3CA野生型结直肠癌肿瘤组织中,双歧杆菌属与假单胞菌呈正相关。结论:PIK3CA突变型与野生型结直肠癌患者肿瘤组织中的微生物群落结构有显著性差异,且PIK3CA突变患者中的肠道微生物多样性更丰富。

从“经济人”走向“教育人”——论“教育人”的实践逻辑

人性假设代表一门学科理论的基本出发点、命题特征与逻辑倾向,并以此影响理论建构与实践。“经济人”假设在教育理论与教育实践中具有深远影响,却陷入了从“个人利益最大化”的经济学假设起点推导“教以成人”教育目的的逻辑悖论,“经济人”逻辑指导下的教育实践显性资源收益性导向违背了育人的初衷、短周期的反馈形式加剧了教育实践的短视、单一的培养目标造就了单向度的人等问题,使其虽具有较高接受度但却易使教育实践走向功利主义。“教育人”是基于教育理论与实践提出的人性假设,“教育人”逻辑更具教育实践与教育学的“合理性”,更符合新时代对教育提出的新要求。通过宏观层面遵循新时代对教育的新导向,中观层面构建牵引性教育反馈机制,微观层面明晰协整性教育多元评价体系相结合,最终达到以经济实践手段促进教育目标、实现“教以成人”的核心目的。

Nocturnal Low-levelWinds and Their Impacts on Particulate Matter over the Beijing Area

Three-month wind profiles, 260 m PM_1 concentrations [i.e., particulate matter(PM) with an aerodynamic diameter ≤1μm], and carrier-to-noise ratio data at two Beijing sites 55 km apart(urban and suburban) were collected to analyze the characteristics of low-level nocturnal wind and PM in autumn and winter. Three mountain-plain wind events with wind shear were selected for analysis. The measurements indicated that the maximum wind speeds of the northerly weak low-level jet(LLJ) below 320 m at the suburban site were weaker than those at the urban site, and the LLJ heights and depths at the suburban site were lower than those at the urban site. The nocturnal 140 m mean vertical velocities and the variations in vertical velocity at the urban site were larger than those at the suburban site. A nocturnal breeze with a weak LLJ of ～3 m s^(-1) noticeably offset nocturnal PM transport due to southerly flow and convergence within the northern urban area of Beijing. Characteristics of the nocturnal LLJ, such as start-up time, structure, intensity, and duration, were important factors in determining the decrease in the nocturnal horizontal range and site-based low-level variations in PM.

Recent advances in the development of in vitro liver models for hepatotoxicity testing

Liver injury is a common cause of drug approval withdrawal during drug development,pre-clinical research,and clinical treatment.If not properly treated,patients with severe liver injury can suffer from acute liver failure or even death.Thus,utilization of the convenient in vitro hepatotoxicity assessment model for early detection of drug-induced hepatotoxicity is vital for drug development and safe personalized medication.Biomaterials(e.g.,hydrogels,nanofibers,decellularized liver matrix)and bioengineering technologies(e.g.,microarrays,micropatterns,3D printing,and microfluidics)have been applied for in vitro hepatotoxicity assessment models.This review summarizes the structure and functions of the liver as well as the components of in vitro hepatotoxicity assessment models.In addition,it highlights the latest advances in developing hepatotoxicity models with the ultimate goal of further clinical translation.

Embedding Implicit User Importance for Group Recommendation

Group recommendations derive from a phenomenon in which people tend to participate in activities together regardless of whether they are online or in reality,which creates real scenarios and promotes the development of group recommendation systems.Different from traditional personalized recommendation methods,which are concerned only with the accuracy of recommendations for individuals,group recommendation is expected to balance the needs of multiple users.Building a proper model for a group of users to improve the quality of a recommended list and to achieve a better recommendation has become a large challenge for group recommendation applications.Existing studies often focus on explicit user characteristics,such as gender,occupation,and social status,to analyze the importance of users for modeling group preferences.However,it is usually difficult to obtain extra user information,especially for ad hoc groups.To this end,we design a novel entropy-based method that extracts users’implicit characteristics from users’historical ratings to obtain the weights of group members.These weights represent user importance so that we can obtain group preferences according to user weights and then model the group decision process to make a recommendation.We evaluate our method for the two metrics of recommendation relevance and overall ratings of recommended items.We compare our method to baselines,and experimental results show that our method achieves a significant improvement in group recommendation performance.

Platelet rich plasma-complexed hydrogel glue enhances skin wound healing in a diabetic rat model

Diabetic patients often exhibit delayed or incomplete progress in the healing of acute wounds,owing to poor blood perfusion.Platelet-rich plasma(PRP)has attracted much attention as a means to improve wound healing,because it contains high growth factor concentrations.However,the burst-like release of PRP growth factors results in a short halflife of these therapeutic proteins,thus greatly limiting the therapeutic effect.In this study,we prepared PRP from human umbilical cord blood and developed an in situ photocrosslinkable PRP hydrogel glue(HNPRP)by adding a photoresponsive hyaluronic acid(HA-NB)into PRP.The HNPRP hydrogel allowed for controlled release of plateletderived growth factor-BB(PDGF-BB)and transforming growth factor-β(TGF-β)for up to 28 days.In vitro cell culture showed that HNPRP promoted migration of fibroblasts and keratinocytes as well as PRP and did not reveal the advantages of HNPRP.However,in a diabetic rat skin wound model,HNPRP treatment promoted faster wound closure.Furthermore,the HNPRP group,compared with the control,PRP and hydrogel only groups,showed significantly greater re-epithelialization and numbers of both newly formed and mature blood vessels.The HNPRP group also displayed higher collagen formation than did the control group.In conclusion,HNPRP enhances angiogenesis and skin regeneration and consequently achieves faster wound healing,thus extending its potential for clinical applications to treat diabetic skin wounds.

Antithrombotic Therapy:Focus on the Elderly

Advanced age brings a higher incidence of thrombosis-related diseases.Although antithrombotic therapy significantly reduces the risk of ischemic events,relatively higher bleeding rates result in increased mortality and worse prognosis in the elderly.Thus the benefits and harms of antithrombotic drugs should to be carefully evaluated.In this review,we summarize current evidence and updated guidelines regarding antithrombotic therapy in the aging population.

The Application of Novel Electrochemical Approach to Antioxidant Activity Assay of Metal Porphyrins with Bulky 3,5-Diisobornyl-4-hydroxyphenyl Moieties

The complexes of biogenic metals (Zn2+,Cu2+,Co2+,Mn3+,Fe3+) based on meso-tetra(3,5-diisobor- nyl-4-hydroxyphenyl)porphyrin 1 were synthesized. The electrochemical behavior of these com-pounds was studied using cyclic voltammetry (CV) and rotating disk electrode (RDE) techniques. The antioxidant activity of complexes was estimated by means of the electrochemical assay based on the hydrogen atom transfer reaction to the stable radical 2,2’-diphenyl-1-picrylhydrazyl (DPPH). The RDE method was applied for this process monitoring. It was shown that the efficiency of the metal complexes (Cu2+,Co2+,Mn2+,Ni2+,Fe3+) is practically the same order as that of free base porphyrin 1. However the Zn2+ complex demonstrates significantly higher antioxidant activity, and the stoichiometry of the reaction was determined as σ = 4. The results demonstrate that porphyrin macrocycle can directly affect the antioxidant properties of 2,6-diisobornylphenol.

Pomegranate-like ATO/SiO_(2)microspheres for efficient microwave absorption in wide temperature spectrum

High-performance microwave-absorbing materials(MAMs)should meet both impedance matching and attenuation performance.Commonly,it is hard to maintain excellent microwave absorption(MA)per-formance at an elevated temperature because the reliance on impedance matching and dielectric loss about temperature mutually restricts.In this work,the pomegranate-like antimony-doped tin dioxide(ATO)/silica dioxide(SiO_(2))spheres were fabricated via a simple spray drying process.When the spheres were used as functional units and dispersed in the matrix,the corresponding composites exhibit an out-standing anti-reflection effect on microwaves.Moreover,the unique pomegranate-like structure of the ATO/SiO_(2)spheres provides both the effective local eddy current and abundant heterogeneous interface,which therefore contribute harvest enhanced dielectric relaxation and improved absorption performance when compared with that of the corresponding ATO/SiO_(2)composition.As a result,the maximum re-flection loss of the ATO/SiO_(2)spheres composites can reach-47.8 dB at 9.7 GHz with a thickness of 1.8 mm,while the reflection loss could reach-47.3 dB at 573 K and the effective absorption bandwidth is 2.4 GHz.This work reveals the importance of local eddy current loss in optimizing the electromagnetic wave(EMW)absorption performance and impedance matching,providing novel guidance on designing advanced high-temperature MAMs.

Flexible regulation engineering of titanium nitride nanofibrous membranes for efficient electromagnetic microwave absorption in wide temperature spectrum

Simultaneous development of well impedance matching and strong loss capability has become a mainstream method for achieving outstanding electromagnetic microwave absorption(EMWA)performances over wide temperature range.However,it is difficult to pursue both due to the mutual restraint of relationship between impedance matching and loss capability about temperature.Here,we propose a flexible regulation engineering of titanium nitride(TiN)nanofibrous membranes(NMs,TNMs),which could be distributed uniformly in the polydimethylsiloxane(PDMS)matrix and contributed to the formation of abundant local conductive networks,generating the local conductive loss and enhancing the loss ability of EMWs.Moreover,when the TNMs are used as functional units and dispersed in the matrix,the corresponding composites exhibit an outstanding anti-reflection effect on microwaves.As hoped,under the precondition of good impedance matching,local conductive loss and polarization loss together improve the loss capacity at room temperature,and polarization loss can compensate the local conductive loss to acquire effective dielectric response at elevated temperature.Benefiting from the reasonably synergistic loss ability caused by flexible regulation engineering,the corresponding composites exhibit the perfect EMWA performances in a wide temperature range from 298 to 573 K.This work not only elaborates the ponderable insights of independent membrane in the composition-structure-function connection,but also provides a feasible tactic for resolving coexistence of well impedance matching and strong loss capability issues in wide temperature spectrum.

Controlling electrodeposited Ni layers by different-sized graphene oxides enables conductive e-textiles for the highly sensitive electrochemical detection of glucose

With the increasing popularity of wearable electronic devices,there is an urgent demand to develop electronic textiles(e-textiles)for device fabrication.Nevertheless,the difficulty in reconciliation between conductivity and manufacturing costs hinders their large-scale practical applications.Herein,we reported a facile and economic method for preparing conductive e-textiles.Specifically,nonconductive polypropylene(PP)was wrapped by reduced graphene oxide(rGO),followed by the electrodeposition of Ni nanoparticles(NPs).Notably,modulating the sheet size of graphene oxide(GO)resulted in controllable deposition of Ni NPs with adjustable size,allowing for controlled manipulations over the structures,morphologies,and conductivity of the obtained e-textiles,which influenced their performance in electrochemical glucose detection subsequently.The optimal material,denoted as Ni/rGO+(0.2)/PP,exhibited an impressive conductivity of 7.94×10^(4)S·m^(−1).With regard to the excellent conductivity of the as-prepared e-textiles and the high electrocatalytic activity of Ni for glucose oxidation,the asprepared e-textiles were subjected to glucose detection.It was worth emphasizing that the Ni/rGO_(0.2)/PP-based electrode demonstrated promising performance for nonenzymatic/label-free glucose detection,with a detection limit of 0.36μM and a linear response range of 0.5μM to 1 mM.This study paves the way for further development and application prospects of conductive etextiles.

Boosted microwave absorption performance of transition metal doped TiN fibers at elevated temperature

Due to the temperature and frequency response of electromagnetic(EM)loss,how to realize the effective design of microwave absorption materials(MWAMs)at elevated temperature is highly desirable for practical applications.Herein,transition metaldoped titanium nitride(M-TiN,M=Fe or Co)fibers were fabricated,the distortion of TiN lattice could cause the adjustable charge enrichment,which played a profound influence on the dielectric response and EM microwave absorption(EMWA)performances.Benefiting from the negative correlation between dielectric loss and temperature,more loss mechanism could be introduced,which would effectively enhance dielectric loss and EMWA performances at elevated temperature.The optimal EMWA performances of Fe-TiN fibers/polydimethylsiloxane(PDMS)composites were realized with a wide temperature range(298–423 K):the reflection loss(RL)could reach 99%(RL<−20 dB)at 12.2 GHz with 1.8 mm,when the filler content was only 15.0 wt.%.Compared with the undoped-TiN fibers/PDMS and Co-TiN fibers/PDMS composites,the excellent EMWA of Fe-TiN fibers/PDMS composite could be attributed to the reasonably synergistic polarization loss and conduction loss.Based on systematic analysis of the variable-temperature EM parameters and EMWA performances,the optimization of EMWA performances in wide temperature domain could be realized by introducing appropriate polarization loss and its compensating.Hopefully,this work provides a new strategy for regulating the dielectric response and designing effective MWAMs at elevated temperature.

北京地区四个豹猫亚种群肠道菌群的组成

野生动物的肠道微生物组成受食物资源和遗传属性的影响较大,为了解北京地区小型猫科动物肠道菌群组成特点及其影响因素,本研究通过扩增细菌16S rRNA的V3‒V4高变区进行高通量测序,对云蒙山、云峰山、松山、百花山4个区域的豹猫(Prionailurus bengalensis)亚种群进行肠道菌群组成分析。结果表明,在门水平上,豹猫的肠道优势菌群主要由厚壁菌门(相对多度52.40%)、变形菌门(25.18%)、放线菌门(9.07%)、拟杆菌门(8.17%)和梭杆菌门(4.74%)组成。在属水平上,相对多度最高的前5个属为假单胞菌属(Pseudomonas,13.37%)、布劳特氏菌属(Blautia,11.20%)、梭菌属(Clostridium_sensu_stricto_1,9.10%)、消化梭菌属(Peptoclostridium,8.62%)、乳杆菌属(Lactobacillus,6.08%),共约占总多度的50%。各区域豹猫亚种群的肠道菌群β多样性不存在显著差异,松山区域的ACE指数和Chao 1指数与云蒙山和云峰山存在显著差异。鉴于松山亚种群的遗传结构与其他区域有所不同,而4个区域的气候类型和豹猫食物构成相似性高,推测该亚种群的肠道菌群主要受遗传结构分化的影响,对此还需进一步研究。