定标活检术在肠道黏膜中临床应用价值的探讨及分析

目的 评价定标活检术在肠道黏膜中的应用价值.方法 选择行肠镜检查的患者89例,使用一次性定标活检钳在其肠道黏膜进行标记,通过定期复查肠镜,分析单次标记成功率、标记的存在情况、标记局部黏膜的组织反应及其并发症等情况.结果 89例患者中单次定标成功率84.27％,总有效率96.63％.随访超过6个月、12个月、1 8个月和24个月的患者中,定标总有效率分别为82.35％、78.56％、76.54％和67.89％.结论 定标活检术在肠道黏膜中具有标识清晰,留存时间较长,适合肠道疾病的纵向对比研究,临床推广意义较大.     

Identification and characterization of novel synthetic cannabinoid ethyl-2-(1-(5-fluoropentyl)-1H-indole-3-carboxamido)-3,3-dimethylbutanoate (5F-EDMB-PICA)

Forensic Toxicology - The purpose of the current study was to evaluate an analytical characterization of a novel synthetic cannabinoid...     

A novel therapeutic strategy for adolescent idiopathic scoliosis based on osteoporotic concept

Adolescent idiopathic scoliosis (AIS) is a complex three dimensional spinal deformity which occurs mostly in prepubertal and pubertal girls. Although bracing and surgery have been the mainstays of treatment for AIS, because of the complications and poor compliance, many patients with this disorder continue to experience significant residual symptoms. The etiology and pathogenesis of AIS is unclear, but recent studies show the association between osteopenia and AIS and imply that osteopenia play a causative role in the development of AIS. Anti-osteoporosis treatment can improve bone strength, prevent osteoporosis and rebalance the OPG–RANK–RANKL system, which may help to prevent curve progression in AIS. This report proposes that anti-osteoporosis treatment may be an effective treatment for AIS.     

Spacer layer design for efficient fully printable mesoscopic perovskite solar cells

The spacer layer is a key component of fully printable mesoscopic perovskite solar cells, but its precise characteristics are far from being understood in relation to the device design. In the present work, we perform a detailed systematic study on the effects of spacer parameters, such as size of building blocks, layer thickness, etc., on properties of the perovskite filler, insulating ability and performance of fully printable mesoscopic perovskite solar cells by combining the techniques of time-resolved photoluminescence, high-resolution TEM, insulating resistance measurements, impedance spectroscopy and J–V characteristics. Drawing on the deep understanding from these studies, we formulate key principles, which are anticipated to guide the design of the advanced spacer layer for fully printable mesoscopic perovskite solar cells.

Key principles and reasonable routes are proposed to advance the spacer layer design for fully printable mesoscopic perovskite solar cells.

Lead halide perovskite (PVSK) as a promising semiconducting material has been introduced as a light harvesting semiconductor because of its ease of fabrication and excellent physical properties, such as tunable bandgap, strong absorbance, long carrier diffusion length and shallow intrinsic trap state level.^1–9 Extremely flat and compact perovskite thin film with large crystal size has gained particular attention to boost power conversion efficiency (PCE) by sequential deposition method, vapor deposition, solvent-annealing, solvent engineering, hot-casting method, intramolecular exchange methods, and additive, etc.^10–16 Benefiting from rapid improvements in formation of high quality perovskite thin film, a certified PCE of 25.2% has been achieved.¹⁷ However, illumination stability in real environment still remains a serious challenge due to the inherent moisture and UV sensitivity of perovskite. Moreover, using expensive and rare metals as back contact, such as gold and silver, may limit large-scale production in the future. As the competing architecture of perovskite solar cells, TiO₂/spacer/carbon (abbreviated as TSC) films based fully printable mesoscopic perovskite solar cells (FP-MPSC) have attracted a lot of researchers due to their low cost and printable large-scale production process.^18–21 In this type of solar cell, carbon can efficiently collect hole from perovskite layer even without any other hole transporting materials.^22,23 Most importantly, FP-MPSC could work with excellent illumination stability and heat-stress stability by filling TSC films with (5-AVA)_xMA_1−xPbI₃ (5-AVA = 5-aminovaleric acid, MA = methylammonium), although the efficiency of 12.8% is still far behind from the most efficient solar cell.^16,21,24Spacer, as an important part of FP-MPSC, plays a crucial role in obtaining high performance device. Basically, the spacer layer mainly burdens triple important tasks in the efficient mesoscopic perovskite solar cells. Firstly, the core function of spacer is to separate anode and cathode and to prevent electrons in TiO₂ from transporting directly to carbon electrode. The separating property of spacer depends on spacer particle sizes, morphology, materials, etc. This requires that spacer layer has no cracking and has wide bandgap. Secondly, the perovskite confined in the mesopores of spacer layer can absorb photons transmitted through perovskite/TiO₂ composite layer and have contribution to photocurrents. Thirdly, the holes produced in the perovskite/TiO₂ composite layer have to go through perovskite/spacer composite layer to reach carbon electrode. And the electrons produced in the perovskite/spacer composite layer have to go through perovskite/spacer composite layer to reach TiO₂ electrode. Because spacer layer has these important functions, some research on spacer layer have been carried out. Recently, Al₂O₃ or ZrO₂ spacer layer was compared with respect to their pore size.²⁵ However, conclusion of the effect of pore size in two different materials was incomplete. The effect of spacer layer thickness was simply discussed both in monolithic dye-sensitized solar cells and FP-MPSC.^20,26 The morphology of spacer layer was also improved to increase PCE of FP-MPSC.²⁷ Although these researches made some progress, there are no clear standards that what should an ideal spacer layer satisfy. Therefore, it is urgent to carry out detailed study on how the parameters of spacer affect the above functions and performance of mesoscopic printable perovskite solar cells.In the present study, the effects of size of building blocks of spacer layer, thickness of spacer layer on property of perovskite crystals, insulating property, and performance of mesoscopic perovskite solar cells were investigated in details. Based on these deep understandings, critical principles to design advanced spacer layer are proposed.ZrO₂ is used as spacer material due to its large band gap and high conduction band energy level. There are five different sizes of spacer building blocks in this study. The average particle sizes of spacer are measured to be about 5 nm, 10 nm, 20 nm, 60 nm and 100 nm, respectively, and hereafter referred to as S5, S10, S20, S60, S100 spacer, respectively. SEM images of as-prepared spacer films using these building blocks are shown in Fig. 1. X-ray diffraction patterns of spacer film with different particle sizes are presented in Fig. 1f, indicating that the five spacer films were all tetragonal crystal phase as majority phase. From Scherrer equation, the crystal sizes of spacer building blocks were calculated to be about 5 nm, 10 nm, 20 nm, 30 nm, 30 nm, respectively. These results indicated that the S60 and S100 particles are consisted of 30 nm sized crystal ZrO₂. Fig. 1 presents that there is a large difference in surface morphology with particle size increasing. There are cracks in S5 and S10 spacer films and micrometer scale pores exist in the S100 spacer, while the surface of S20 and S60 are very uniform without defects.Open in a separate windowFig. 1SEM images of spacer films with particle size of 5 nm (a), 10 nm (b), 20 nm (c), 60 nm (d) and 100 nm (e), respectively. (f) XRD patterns of spacer film with different building block sizes.During solvent evaporation of perovskite precursor, perovskite crystal growth is restricted by randomly interconnected mesopores of spacer film, leading to nanoscale crystal size and random crystal orientation, as observed by high resolution transmission electron microscope (Fig. 2a), in which clear crystal lattices of perovskite crystals can be distinguished from spacer particles. Meanwhile, the mesopores of spacer film is fulfilled with perovskite materials, providing continuous channels for charge carriers. The crystal size of perovskite material in spacer film is strongly influenced by mesopore size of spacer layer, as seen in XRD intensity of perovskite at 2θ of about 14.2° (Fig. 2b). There is an apparent trend that the intensity increased with increasing the particle size of spacer film. As a reference, perovskite was also deposited on bare glass, which exhibited the best crystallinity. The calculated sizes of perovskite from XRD spectra are 4.3 nm, 3.9 nm, 6.2 nm, 11.5 nm, and 12.6 nm, respectively, for the S5, S10, S20, S60, and S100 spacer layer. Apparently, the sizes of perovskite crystals confined in the spacer layer are smaller than the average pore sizes of spacer layer measured by N₂ absorption/desorption isotherms (Table S1^†). The high-resolution TEM image also gives consistent results. For example, the sizes of perovskite crystals confined in the S20 spacer layer are between 8.4 nm to 12.7 nm measured in the TEM image (Fig. 2a). The infiltrated perovskite started to nucleate onto the heterogeneous surface of spacer building blocks with high surface area, resulting to multiple nucleation centers and small crystal size. In order to evaluate the effect of spacer particle size on physiochemical properties of perovskite, the band-edge emission spectra of perovskite/spacer composite film were measured in Fig. 2c. The band-edge emission spectrum of perovskite deposited on bare glass peaked at 762 nm (with photon energy of 1.627 eV). As the particle size of spacer film decreased, a blue shift of the band-edge photoluminescence occurred, and linewidth broadened. The peak position of perovskite emission spectra can be tuned in the range of 33 nm through varying the pore size of spacer film. The increase of emission line width at grain boundaries can be attributed to disorder and defects of perovskite,^14,15 which also led to the decrease of lifetime in time-resolved PL (Fig. 2d). Perovskite film grown on glass has the lifetime of 141.9 ns. However, perovskite grown in spacer film decreased to 0.5 ns, 8.4 ns, 24.1 ns, 37.2 ns, 53.7 ns, for S5, S10, S20, S60, S100, respectively.Open in a separate windowFig. 2(a) High resolution transmission electron microscope image of perovskite/S20 spacer film composite. (b) XRD of perovskite/spacer film composite. (c) Steady PL emission spectra and (d) time-resolved PL of perovskite/spacer film composite.The particle size of spacer also has large effect on insulating ability of spacer films with the same thickness. FTO/spacer/carbon configuration was designed to measure the insulating ability of spacer layers. In ideal conditions, the resistance between carbon and FTO, defined as insulating resistance (R_I), should be infinite, indicating that there is not any leakage current from ideal insulating spacer. However, all of the measured resistance has finite values, summarized in 28–31Photovoltaic parameters of mesoscopic perovskite solar cells based on spacer with different building block sizes

Corona Virus Disease 2019 patients with different disease severity or age range: A single-center study of clinical features and prognosis

This study aimed to describe clinical characteristics and prognosis of Corona Virus Disease 2019 (COVID-19) patients, and to compare these features among COVID-19 patients with different disease severity or age range.Totally, 129 COVID-19 patients were retrospectively enrolled, and the information about demographics, comorbidities, medical histories, clinical symptoms, and laboratory findings at the time of hospital admission were collected. Meanwhile, their clinical outcomes were recorded. According to the fourth version of the guidelines on the Diagnosis and Treatment of COVID-19 by the National Health Commission of China, patients were divided into subgroups according to disease severity (moderate and severe/critical) or age (<40 years, 40–64 years and ≥65 years).In total patients, the most common clinical symptoms were fever and cough (all incidences over 50%). Other common clinical symptoms included tiredness/anorexia, shortness of breath, dyspnea, aching pain, expectoration, diarrhea, shivering, and nausea/vomiting. The mortality rate was 5.4%, and the median value of hospital stay was 16.0 (11.0–23.0) days. Subgroup analyses disclosed that severe/critical patients exhibited increased neutrophil count, neutrophils, C-reactive protein, calcitonin, alpha-hydroxybutyric dehydrogenase, lactate dehydrogenase, aspartate aminotransferase, gamma-glutamyl transferase, creatinine, and D-dimer levels, and more deaths compared with that in moderate patients. Regarding age, it correlated with more common fever, higher levels of red blood cell, neutrophil count, lymphocyte count, neutrophils, red cell volume distribution width standard deviation-coefficient of variation, calcitonin, alpha-hydroxybutyric dehydrogenase, Creatine Kinase, aspartate aminotransferase, gamma-glutamyl transferase, and D-dimer, raised death rate and prolonged hospital stay.Our findings provide valuable evidence regarding clinical characteristics and prognosis of COVID-19 patients to help with the understanding of the disease and prognosis improvement.     

Relation between the particle size and release characteristics of aromatic melamine microcapsules in functional textile applications

The relation between the particle size and release characteristics of aromatic microcapsules with a melamine resin shell in functional textile applications have been investigated. Firstly, the microcapsules are characterized based on their Fourier transform infrared spectra, encapsulation efficiencies, particle size distributions, optical images, and scanning electron microscopy images. The impregnation performances of the microcapsules have been initially evaluated using image analysis. Subsequently, the impregnation efficiency and broken release characteristics are semi-quantitatively analyzed using solid-phase microextraction-gas chromatography-mass spectrometry. The analysis results show that the highest impregnation efficiency and broken release intensity could be observed when the microcapsule size was similar to the fiber diameter (25–30 μm). Eventually, the sustained release of the microcapsules over a period of 2400 h was evaluated using the weighing calculation method, and the trends were studied using the Peppas model. It was found that the microcapsule release rate slowly and continuously decreased with time, and the release rates significantly increased with the decrease in microcapsule particle size. Thus, it could be concluded that the large microcapsules exhibited better leak tightness than the small microcapsules, whereas the small microcapsules exhibited faster sustained release rates.

The relation between the particle size and release characteristics of aromatic microcapsules with a melamine resin shell in functional textile applications have been investigated.     

医药工业洁净室悬浮粒子的测量不确定度评定

目的：评定洁净室悬浮粒子的测量不确定度。方法对悬浮粒子的测量不确定度来源分析,建立数学模型,逐项评定悬浮粒子的不确定度的分量,合成标准不确定度,最后得出测量结果的扩展不确定度。结果粒径≥0.5μm的悬浮粒子数为（10490±2472）粒/m3,k=2;粒径≥5μm的悬浮粒子数为（923±296）粒/m3, k=2。结论悬浮粒子的测量不确定度主要来源是仪器的计量性能及试验重复性引起的不确定度,测量时应注意采样点的均匀性及代表性,多点采样,以减少不确定度,提高结果的可靠性。     

Effect of Calcination Temperature on Mechanical Properties of Magnesium Oxychloride Cement

In order to make full use of magnesium chloride resources, the development and utilisation of magnesium oxychloride cement have become an ecological and economic goal. Thus far, however, investigations into the effects on these cements of high temperatures are lacking. Herein, magnesium oxychloride cement was calcinated at various temperatures and the effects of calcination temperature on microstructure, phase composition, flexural strength, and compressive strength were studied by scanning electron microscopy, X-ray diffraction, and compression testing. The mechanical properties varied strongly with calcination temperature. Before calcination, magnesium oxychloride cement has a needle-like micromorphology and includes Mg(OH)₂ gel and a trace amount of gel water as well as 5 Mg(OH)₂·MgCl₂·8H₂O, which together provide its mechanical properties (flexural strength, 18.4 MPa; compressive strength, and 113.3 MPa). After calcination at 100 °C, the gel water is volatilised and the flexural strength is decreased by 57.07% but there is no significant change in the compressive strength. Calcination at 400 °C results in the magnesium oxychloride cement becoming fibrous and mainly consisting of Mg(OH)₂ gel, which helps to maintain its high compressive strength (65.7 MPa). When the calcination temperature is 450 °C, the microstructure becomes powdery, the cement is mainly composed of MgO, and the flexural and compressive strengths are completely lost.