子宫内膜癌患者手术治疗前后血清 CA125、HE4和D-D水平检测的临床意义

目的 探讨了解子宫内膜癌患者手术治疗前后血清CA125、HE4和D-D水平的变化及临床意义。方法 应用放射免疫法,酶联法和免疫比浊法对31例子宫内膜癌患者进行了手术治疗前后血清CA125、HE4和D-D水平的检测,并与35名正常健康人作比较。结果 子宫内膜癌患者在手术治疗前血清CA125、HE4和D-D水平均非常显著地高于正常人组(P＜0.01),手术治疗6个月后则与正常人比较无显著性差异(P＞0.05)。血清CA125水平与HF4、D-D水平呈显著正相关,(r=0.5918、0.4725,P＜0.01)。结论 检测子宫内膜癌患者手术治疗前后血清CA125、HE4、D-D水平的变化对了解病情、观察疗效和预后判定均具有重要的临床价值.     

从温阳透发法论治难治性痤疮

痤疮可辨为阴、阳两证。阳疮者,缘患者劳汗被寒、玄府闭合,汗脂凝聚日久不得外排,蕴热搏结气血而生疮化腐,疮症为热为痛,此为易治;阴疮者,由阳疮转化而来,缘患者外感寒风、内伤生冷,且医者又重用寒凉、失于托透,以至气血冰凝,久不溃脓或溃脓难出,此为难治。根据难治性痤疮临床表现,其多类属于阴疮,以阳虚表郁、邪闭毛窍为致病之关键,其中表郁毛窍、邪闭肌腠为病之标,阳虚阴凝为病之本。治疗当以温阳透发、祛邪外达为法。以麻黄附子细辛汤温阳化阴滞、发阳透毒治其本,待阴邪发越,即用火针强开门户、消疮排脓治其标。标本兼治、针药结合的方法治疗难治性痤疮在临床中能够安全有效地消除痤疮、改善皮损、降低复发率。     

2013年医院感染现患率调查及危险因素分析

目的了解某院医院感染的现状以及抗菌药物的使用情况。方法采用横断面调查的方法,对2013年8月21日该院所有住院患者医院感染现患率、抗菌药物使用情况以及病原学送检率进行调查。结果共调查住院患者2 238例,发生医院感染104例,126例次,医院感染现患率为4.65%,例次现患率为5.63%。医院感染部位居前4位的是下呼吸道（28.57%）、上呼吸道（18.25%）、泌尿道（7.94%）和胃肠道（4.76%）;标本送检率为91.35%（95/104）,标本来源以痰液（26.32%）居首位,其次为血液（25.26%）、尿液（10.53%）等。抗菌药物使用率为24.58%,其中治疗、预防+治疗、预防用药分别占36.55%、45.09%和18.36%;抗菌药物单一、二联和三联用药率分别为75.82%、20.91%、3.27%。危险因素分析结果显示,年龄（＜15岁或＞60岁）、各种侵入性操作（气管切开、使用呼吸机、泌尿道插管、动静脉置管和血液透析）、抗肿瘤化学治疗是医院感染的危险因素。结论医院感染现患率调查有助于了解医院感染和抗菌药物使用情况,以及发生医院感染的高危因素和高危科室,为后期有效开展医院感染目标性监测提供有力的依据。     

吡柔比星联合维拉帕米膀胱灌注对膀胱癌术后复发的预防效果分析

目的:探讨吡柔比星联合维拉帕米膀胱灌注治疗应用于膀胱上皮癌术后复发的效果及安全性。方法:将本院收治的54例膀胱上皮癌行经尿道膀胱肿瘤电切术(TURBT)或膀胱部分切除术患者随机分为实验组和对照组,实验组患者给予吡柔比星联合维拉帕米膀胱灌注治疗,对照组患者给予吡柔比星膀胱灌注治疗。随访观察5年,比较两组患者1年、3年、5年的累计复发率,以及治疗过程中膀胱刺激征、血尿、化学性膀胱炎等不良反应发生率。结果:实验组1年、3年、5年的累计复发率分别为3.7%、7.4%、11.1%,不良反应发生率为51.9%;对照组1年、3年、5年的累计复发率分别为14.8%、29.6%、37.0%,不良反应发生率为48.1%。实验组3年、5年累积复发率显著低于对照组(P<0.05),不良反应发生率无显著差异(P>0.05)。结论:在吡柔比星膀胱灌注的基础上,联合应用维拉帕米能够显著降低膀胱上皮癌术后复发率并保留患者的性功能,且安全性较高,值得临床推广应用。     

Analysis of early mortality and related risk factors in maintenance hemodialysis patients

Objective To analyze the early mortality and related risk factors of new hemodialysis patients in Zhejiang province, and provide basis for reducing the death risk of hemodialysis patients. Methods The early mortality and related factors of new hemodialysis patients from January 1, 2010 to June 30, 2018 were retrospectively analyzed using the database of Zhejiang province hemodialysis registration. The early mortality was defined as death within 90 days of dialysis. Cox regression model was used to analyze the related risk factors of the early mortality in hemodialysis patients. Results The mortality was the highest in the first month after dialysis (46.40/100 person year), and gradually stabilized after three months. The early mortality was 25.33/100 person year. The mortality within 120 days and 360 days were 21.40/100 person year and 11.37/100 person year, respectively. The elderly (≥65 years old, HR=1.981, 95%CI 1.319-2.977, P＜0.001), primary tumor (HR=3.308, 95%CI 1.137-5.624, P=0.028), combined with tumors (not including the primary tumor, HR=2.327, 95%CI 1.200-4.513, P=0.012), temporary catheter (the initial dialysis pathway, HR=3.632, 95%CI 1.806-7.307, P＜0.001), lower albumin (＜30 g/L, HR=2.181, 95%CI 1.459-3.260, P＜0.001), lower hemoglobin (every 0.01 g/L increase, HR=0.861, 95%CI 0.793-0.935, P=0.001), lower high density lipoprotein (＜0.7 mmol/L, HR=1.796, 95%CI 1.068-3.019, P=0.027) and higher C reactive protein (≥40 mg/L, HR=1.889, 95%CI 1.185-3.012, P=0.008) were the risk factors of early death for hemodialysis patients. Conclusions The early mortality of hemodialysis patients is high after dialysis, and gradually stable after 3 months. The elderly, primary tumor, combined with tumors, the initial dialysis pathway, lower albumin, lower hemoglobin, lower high density lipoprotein and higher C reactive protein are the risk factors of early death for hemodialysis patients.     

长宁社区腰椎间盘突出症患者病因学和中医证型的调查研究

目的:通过对长宁社区腰椎间盘突出症的分布规律、中医证型特点和诊治现状进行调查统计,对其原发病因、中医证型与效应指标之间的关系进行分析.方法:随机取样收集病例500例,采用SPSS 13.0软件包,对患者的症状、体征、舌脉采用K-means聚类分析,再对各种类型进行主成分分析,判定各种类型的代表症状,归纳出基本证型;对每位患者的治法和疗效进行分析.结果:调查收集的LDH常见症状24种,症状出现频率较高的是腰骶疼痛、腰腿疼痛、腰部胀痛、单侧下肢放射痛、单侧下肢麻木,活动后加重;症状出现频率较低的是髋部疼痛、鞍区麻木、大小便失禁.91％的患者首选非手术治疗,疗效达95％以上;辨证分型与X线、CT扫描结果有一定的相关性.结论:肝肾亏虚、气滞血瘀是腰椎间盘突出症的根本病机;X线、CT扫描可作为LDH辨证分型的客观指标之一;非手术治疗为LDH首选治疗,疗效满意.     

远古至秦汉中药毒性理论及嬗变的文献研究

毒性是中药的自然属性之一,是中药药性理论的重要组成部分。自远古至秦汉之际,中药的毒性理论,经历了萌芽、发展、深化、充实、提高的嬗变过程,至汉代形成了首次理论总结,具有划时代意义,为后世中药毒性理论的深化发展直至成熟完备奠定了基础。文章通过梳理秦汉之前的史料文献并加以分析,考镜源流,总结用药用毒经验,以期对全面深入地认识现代中药毒性理论及合理运用有毒中药提供借鉴,同时也有助于丰富中药药性理论内涵,更好地指导中医药临床实践。     

琥珀酸美托洛尔缓释微囊的制备和体外释药

 目的 探讨琥珀酸美托洛尔缓释微囊的制备工艺。方法 以乙基纤维素作为囊材,采用乳化-溶剂扩散法,应用均匀设计优化处方和制备工艺,并研究其体外释药特性。结果 在优化条件下制备的琥珀酸美托洛尔缓释微囊,外形圆整光滑,分布均匀,不粘连,平均粒径为80~90 μm,包封率达83.16%,18 h体外释放百分率为96.1%。结论 优化条件下可制备的缓释微囊外观较好、包封率高,在体外具有良好的缓释效果。     

汶川地震后送伤员的临床救治：附50例

目的分析地震伤的诊断和治疗。方法对2008年5月26日～8月4日收治的50例地震伤员的临床资料进行回顾性分析。根据地震伤员的伤情特点,积极手术治疗恢复伤残肢体的功能,共手术38台次。结果50例中男20例,女30例,男女比率为1：1．5。年龄10～88岁,平均48．5岁,18—60岁34例,小于12岁2例,60岁以上14例,其中80岁以上2例。44例来自农村,多数房屋被毁。外伤多发生于四肢和骨盆,复合伤多见。漏诊脊柱骨折5例。手术38台次,均成功,无死亡伤员。结论农村人口多为妇女、儿童,青壮年少,这些人占地震伤员的多数。外伤部位多在四肢及骨盆。开放性伤口较多,感染多见。积极治疗后预后好。     

Facile synthesis and optical properties of colloidal quantum dots/ZnO composite optical resonators

We present a novel colloidal quantum dot (CQD)/ZnO whispering gallery mode microcavity composite. The whispering gallery mode emission of the CQDs induced by the ZnO microcavity is realized. The resonant properties of the composite optical cavities are systematically investigated, and the obtained results are supported by finite element method simulations. The work presents a new research platform to study light–matter interactions in such a composite microcavity.

We present a facile method of incorporating CdSe/Zn_xCd_1−xS CQDs onto the surface of a ZnO WGM optical microcavity. The whispering gallery mode emission of the CQDs induced by the ZnO microcavity is directly observed.

Quantum dots (QDs) feature a quantized energy structure, attracting considerable attention due to their narrow-linewidth emission spectra, high quantum efficiencies, and broad-energy-range size-tunable band gaps.^1,2 In this research field, great efforts have been devoted to the studies of the combination of QDs with optical microcavities, which is very important both for fundamental research on light–matter interactions and for optics- and photonics-related applications. Most of the previously described composite systems feature a distributed Bragg reflector (DBR) structure and self-assembled QDs, which have allowed great progress in the development of single-photon sources,^3,4 photodetectors,^5,6and cavity lasers.^7,8 However, the above QDs (used as gain materials in these composites) were mostly based on III–V semiconductors prepared by molecular beam epitaxy (MBE)⁹ or metal-organic chemical vapor deposition (MOCVD).^10,11 Moreover, DBR-structured microcavities are usually fabricated using MBE, MOCVD, or sputtering, additionally requiring the utilization of electron beam lithography (EBL) and other nano-etching technologies.^12–16 Thus, these sophisticated and expensive fabrication techniques and limited material availability are not conducive to the development of this research field.In contrast, colloidal quantum dots (CQDs) exhibit the advantages of high optical stability, solution processability, and emission wavelength tunability,^17,18 being well suited for use in composite microcavities. However, the hybridization of CQDs is difficult, with the main method used for this purpose also being rather complex, featuring the insertion of a CQDs layer into the DBR structure by spin coating.¹⁹ The methods like epitaxial growth have been used to synthesize and incorporate CQDs into a photonic crystal distributed feedback (PC-DFB) optical cavity,²⁰ or fabricate on-chip microdisk laser.²¹ They all require expensive equipment, e.g. plasma-enhanced chemical vapor deposition (PECVD) or RF frequency sources, and the process of them are also relatively complex. In addition, alkyl modification and drop-coating also have been used to attach CQDs to silica microbeads²² and submicron scale grating structures²³ showing good composite effect. Nano/microstructure optical cavities with regular geometric configurations are another important class of microcavities,^24–26 attracting growing interest due to their ease of synthesis, high tunability, and excellent optical confinement effect. Among these cavities, ZnO microrod hexagonal whispering-gallery-mode (WGM) microcavities are the ones most extensively studied,^27–31 allowing light confinement due to multiple total internal reflection (TIR) at resonator boundaries and thus enabling effective control of light–matter interaction. This control is essential for both fundamental physics research in the field of cavity quantum electrodynamics and the development of cavity-based optoelectronic devices, and it is therefore believed that the formation of CQDs/microcavity composites will promote further progress in the optical modulation of CQDs.Herein, we present a facile method of incorporating CdSe/Zn_xCd_1−xS CQDs onto the surface of a ZnO hexagonal microrod WGM optical cavity. The modulated emission of the CQDs induced by the ZnO microrod cavity was observed. And, the coupling properties of the CQDs/microcavity composite system have been also studied at room temperature. A whispering gallery mode (WGM) was identified by calculations based on the TIR model and further confirmed by Finite Element Method (FEM) simulations. Furthermore, the resonant properties in relation to the CQDs were studied in detail. Notably, we also demonstrate the occurrence of energy transfer between CQDs and the ZnO microcavity. Thus, our work describes a simple method of investigating optical property coupling between CQDs and nano/microstructure optical cavities.Single-crystalline ZnO microrods were grown on a silicon (Si) substrate in a horizontal tube furnace (with no catalysts, carrier gases, low pressure, or templates used) utilizing a reduction–oxidation method similar to that described in our previous report.³² Core/shell CdSe/Zn_xCd_1−xS CQDs were prepared as described elsewhere,³³ purified by centrifugation and decantation using a toluene/ethanol mixture as a solvent, and redispersed in toluene. The CQDs/ZnO microrod composite was prepared by dropcasting the above dispersion onto ZnO microrods deposited on a clean Si wafer to form a thin CQDs film, with the corresponding photoluminescence (PL) spectra recorded after solvent evaporation. The morphology, composition, and microstructures of the obtained samples were characterized by field emission scanning electron microscopy (FE-SEM, Zeiss Auriga S40), high-resolution transmission electron microscopy (HRTEM, JEOL JEM-2010), and energy-dispersive spectroscopy (EDS). The optical properties of a chosen individual ZnO microrod were determined by confocal micro-photoluminescence spectrometry (JY LabRAM HR800 UV) using a 325 nm He–Cd laser as an excitation source. FEM simulations were carried out using commercial finite element software (COMSOL Multiphysics). Fig. 1(a) shows atypical SEM image of as-synthesized ZnO microrods. A large quantity of rod-like microstructures with smooth surface was produced on the Si wafer. Most of the microrods have diameters in the range of 2–5 μm and lengths exceeding 100 μm. Microrods with smaller sizes of about several hundred nanometers were also observed. Fig. 1(b) shows the detailed morphology of a single ZnO microrod with a side length of ∼2 μm. The enlarged SEM image of the microrod exhibits a perfect hexagonal cross section and smooth surfaces, which benefit the formation of natural WGM microcavities and make such microrods ideal carriers for the study of CQDs/microcavity composites. A three-dimensional (3D) scheme of the WGM microcavity of the CQDs/ZnO microrod composite is shown in Fig. 1(c). The composite method is very simple. The CdSe/Zn_xCd_1−xS core/shell semiconductor CQDs solution were dropped on the ZnO microrod. After the solvent evaporation, it then formed a thin film of CQDs. Fig. 1(d) shows the HRTEM image of the CQDs/ZnO microrod composite. It can be clearly seen that a layer of CQDs closely covering the surface of the ZnO microrod. The interface between ZnO surface and CQDs layer was labelled with a red dotted line. The CQDs are well dispersed with a diameter of about 5 nm as marked out by red circles. Meanwhile, the well-resolved lattice fringes demonstrate the highly crystallined nature of the CQDs nanocrystals. Moreover, the EDS elemental mapping further identified the presence of ZnO in the core part and of CdSe/Zn_xCd_1−xS CQDs on the surface (Fig. 1(f–j)).Open in a separate windowFig. 1Typical SEM images of as-synthesized ZnO microrods: (a) low-magnification SEM image; (b) high-magnification SEM image revealing the morphology of an individual ZnO microrod with a hexagonal cross-section; (c) 3D scheme of a single core/shell CQDs and a CQDs/ZnO microrod composite; (d) HRTEM images of the above composite; (e) SEM image of a typical CQDs/ZnO composite; (f–j) EDS elemental mappings of O, Zn, Cd, Se, and S, respectively.The optical properties of the individual ZnO microrod were investigated by confocal micro-photoluminescence spectrometry using an excitation laser focused by a 40× objective to a ∼2 μm spot. PL spectra were recorded using a silicon charge-coupled-device (CCD) detector and a 600 line/mm grating. Photoluminescence imaging was carried out using a self-built confocal micro-photoluminescence spectrometer with a 405 nm laser. Fig. 2(a) shows atypical PL spectrum of the ZnO microrod, revealing the presence of a characteristic ZnO exciton emission in the UV range (around 380 nm) and abroad point defect emission band between 450 and 700 nm with clear modulations. The intensity of defect emission was stronger than that of exciton emission, and the absence of obvious emission resonant modes in the UV emission band were ascribed to a mode spacing too small to be resolved in the narrow UV band, with the optical absorption around the band edge region being larger. Fig. 2(b) depicts an expanded view of resonance peaks between 480 and 590 nm, clearly showing the microrod resonator for both TE (electrical component of light E⊥c-axis) and TM (E∥c-axis) polarization configurations. From the viewpoint of geometrical optics, two kinds of resonant cavity modes may form in the microrod cavity, namely simple WGM microcavities formed by multiple TIR from the six surfaces and F–P modes formed for two pairs of opposite facets. To determine the exact mode responsible for the signal, two adjacent peaks (λ₁ = 519.2 nm, λ₂ = 525.9 nm) of the TM signal were selected to calculate the path length (L) as follows:1where n is the refractive index of the medium, and dn/dλ is the dispersion relation, with Δλ (mode spacing between two adjacent peaks, also called free spectral range, FSR³⁴) = 6.7 nm, n = 2.06 (λ₁ = 519.2 nm), and λdn/dλ = −0.6 obtained using the refractive dispersion of ZnO in ref. 32. The calculated path length equaled ∼15.06 μm, and the side length (R) of the microrod used for the PL measurement equaled 2.94 μm, as determined by SEM imaging. If the resonant modes were simple F–P modes, the deduced values of L would equal 4R, i.e., ∼11.8 μm. Obviously, the calculated effective path length was much smaller than that (15.06 μm) calculated using eqn (1), which proved the above hypothesis wrong. Conversely, for the whispering gallery mode, the relevant path length was calculated as , agreeing with the theoretically calculated value given above. Thus, it was concluded that the observed resonant modes were mainly caused by the effect of the WGM microcavity. For the whispering gallery mode, the incident angle equaled 60°, with one full path featuring six TIRs. Such WGM microcavities can effectively control light emitted from ZnO itself, facilitating the research of light–matter interaction and the development of relevant optical devices.Open in a separate windowFig. 2(a) PL spectrum of an individual ZnO microrod. (b) Enlarged region of the above spectrum from 480 to 590 nm. (c) Corresponding ZnO dispersion relations. (d) Full-range PL spectra of ZnO (blue line), CQDs (blackline) and CQDs/ZnO (red line), respectively; inset shows a fluorescent image of the CQDs/ZnO composite. (e) The PL spectrum of CQDs in the range of 600–725 nm. (f) Corresponding resonator mode numbers of pure ZnO and the CQDs/ZnO composite in the range of 508–536 nm.To further explore the characteristics of the ZnO microrod WGM resonator, we identified the interference order N for TE and TM modes using the following equation:2where n is the refractive index of the ZnO sample, and N is the interference order of the resonant mode. The factor β is dependent on polarization. For TE polarization β = n, for TM polarization β = 1/n.The interference order N of the TE and TM modes were initially identified, using the refractive dispersion of ZnO microtubes.²⁶ The best fit of the interference order (N_TE = 47–66, N_TM = 48–67) was obtained by varying N systematically and the cavity length L within the experimental error. A similar fitting process has been utilized to calculate the refractive indices of ZnO microtubes.³⁵ These two series of integers are the interference orders for the relevant resonant modes between 480 nm and 590 nm. Using the obtained interference orders and the cavity length L, the accurate wavelength–dependent refractive dispersions (n_TE & n_TM) of the ZnO microrod were calculated. The dispersion relation is shown in Fig. 2(c), and the fitting Cauchy dispersion formula as follows:34It is worth noting that at a given wavelength, n_TM is larger than n_TE, with both indices decreasing with increasing wavelength.The formation of a CQDs/ZnO microrod WGM microcavity composite was confirmed by fluorescence imaging, which revealed that the ZnO microrod cavity was decorated with CQDs emitting red light with a wavelength of ∼650 nm (inset in Fig. 2(d)). To further elucidate the optical performance of the composite, we compared it with the PL spectrum of the pure CQDs and ZnO together. Interestingly, we found that some resonant peaks appear in the CQDs emission region in the CQDs/ZnO composite system. This indicates that the light of CQDs may be introduced into the ZnO microcavity and then was modulated. In fact, the thickness of the combined CQDs layer on the surface of the microcavity is critical for the optical resonance of the CQDs. If the combined CQDs layer was too thick, it will weaken the modulated light coupled in the microcavity emitted out. This phenomenon was also observed in other composite system.²⁸ In addition, it is worth noting that the CQDs emission was clearly blue-shifted after hybridization with the microcavity (Fig. 2(e)), probably due the formation of an oxidized layer on the CQDs surface under ambient conditions,²⁸ which also decreased the effective CQDs size. Fig. 2(f) shows an expanded view of resonance peaks between 508 and 536 nm, demonstrating that the resonant modes of the CQDs/ZnO microrod cavity were preferentially TM-polarized and clearly red-shifted, with TE modes being very weak and difficult to observe. This behavior was ascribed to the refractive index change of the medium caused by CQDs hybridization, as described by the following formula:³⁶5where n_CdSe is the refractive index of CQDs. The refractive index³⁷ of CQDs is n_CdSe = 1.73, which is larger than that of the air medium. For the same resonant peak, the wavelength of the resonant peak will increase with the decrease of the relative difference of the refractive index, resulting in a redshift as shown in Fig. 2(f). Moreover, the deposition of a CQDs layer on the surface of the microrod cavity mainly increases the optical loss of the TE polarization mode, complicating its detection.Interestingly, we also noticed that a broad and weak emission in the CQDs/ZnO composite microcavity appears obviously from 400 to 440 nm as shown in Fig. 3(a). And, the intensity of the exciton emission (from 370 to 390 nm) of ZnO decreases. In addition, we found that the CQDs used in our experiments also have a broad and weak emission at the same wavelength band as shown in Fig. 3(b). Moreover, the shape of the emission peak is very similar to that of the composite microcavity at the same region. This indicates there may be energy transfer between the ZnO and the combined CQDs. In fact, the broad weak emission was attributed to CdS CQDs, which synthesized along with the synthesis process of the core/shell CdSe/Zn_xCd_1−xS CQDs. From Fig. 3(c), it is clearly seen that the absorption spectrum of CdS CQDs covers the emission wavelength of the ZnO excitons at ∼390 nm. The central emission wavelength of CdS CQDs is ∼406 nm, and full width at half-maximum is 25 nm. After the CQDs attached to the surface of ZnO microrod, the distance between CQDs and microrod is close enough for fluorescence resonance energy transfer (FRET) to occur. The inset of Fig. 3(c) is the energy band structure of ZnO and CdS CQDs.^2,38 During FRET, the exciton of ZnO, initially in its electronic excited state, transfers its energy to the acceptor CdS via non-radiative dipole–dipole coupling, damping the band gap emission of the ZnO microrod and enhancing the emission intensity of CdS CQDs, which explains the PL spectra shown in Fig. 3(a). However, the above behavior was not observed when a purified CQDs solution (free of CdS CQDs) was used under the same experimental conditions (Fig. 3(d)), further verifying the occurrence of FRET in the CQDs/ZnO composite microcavity.Open in a separate windowFig. 3(a) PL spectra expanded in the range of 360–470 nm. (b) PL spectrum of CQDs in the range of 360–450 nm. (c) Absorption and PL spectra of CdS CQDs, with inset showing a FRET diagram with typical timescales. (d) PL spectra of CdS CQDs–free CdSe/Zn_xCd_1−xS core/shell CQDs, ZnO microrods, and the CQDs/ZnO composite.To clarify the nature of the resonance modes observed in the PL measurements, FEM simulations are used to study such ZnO or CQDs/ZnO microrod composite microcavity with hexagonal cross-section. Because of the two-dimensional (2D) nature of the measured optical modes, we only simulate a 2D model to simplify our calculation. In our simulations, the modeled microcavity with the same hexagonal cross-section as the fabricated microrod shown in Fig. 1(a) (i.e., a side length of 2.94 μm) is placed inside a simulation box surrounded by the well-matched layer boundaries to absorb the scattered electromagnetic fields. Here, TM polarization was chosen for comparing experimental and simulated results, and the dispersive refraction index of ZnO was therefore calculated from the PL spectrum of this material using eqn (3). The refractive index of CQDs was assumed to equal 1.73. And the dispersive refractive index of ZnO described by eqn (3) is directly imported into the software. The background medium in the simulation box was set to air or CdSe for investigating the microcavities of ZnO or the CQDs/ZnO composite, respectively. An electric current source was placed inside the 2D microcavity to excite TM-polarized optical modes. We choose a very dense mesh inside the ZnO microrod (<λ/20) and surrounding air (<λ/10) to guarantee the convergence of our results.The calculated radiation intensity spectra of the current source inside ZnO and CQDs/ZnO composite microcavities are shown in Fig. 4(b and d), respectively, revealing that if the radiation wavelength of the line source matches that of a microcavity resonance mode, its radiation is significantly enhanced, with these peaks being unambiguous signatures of the optical modes excited in the microcavity. In our calculation, the intensity of the current source was identical for all excitation wavelengths and, therefore, key information was provided only by the position of radiation peaks, with its intensity being negligible. For both ZnO and CQDs/ZnO composite microcavities, the resonance peaks of FEM-simulated radiation spectra well matched those observed experimentally (Fig. 4(a–d)), with the slight mismatch observed for CQDs/ZnO at short wavelengths attributed to the slight poor dispersion of CdSe that was ignored in our simulation (Fig. 4(c and d)). If the microcavity is surrounded by CQDs instead of the air, the resonance modes leak out of the ZnO microcavity more easily owing to the increased refraction index of the background medium, which increases the effective optical path for the resonance modes and induces their red shift (Fig. 4(b and d)). To justify these arguments, we further utilized the eigenmode analysis solver of COMSOL Multiphysics to search all eigen resonance modes supported by the two microcavities. For example, Fig. 4(e–h) show the electric field patterns of two representative resonance modes, clearly identifying the features of WGMs with N = 47 and 55. Likewise, the calculated resonance wavelengths (see insets) perfectly matched the peak positions marked by dashed lines in Fig. 4(a–d), demonstrating that N = 55 (N = 47) resonance modes shift from 547.8 nm (618.0 nm) in the ZnO microcavity to 556.9 nm (631.5 nm) in the CQDs/ZnO composite microcavity. In particular, the long-wavelength modes located in the fluorescence region of CdSe can indeed modulate the light emission of CQDs.Open in a separate windowFig. 4Measured PL spectra (a, c) and FEM-simulated radiation spectra (b, d) of a single ZnO microrod (a, b) and a CQDs/ZnO composite (c, d) with a hexagonal cross-section, and the corresponding WGM electric field distributions (e–h) at specified wavelengths.