Influence of carcass weight on instrumental and sensory lamb meat quality in intensive production systems

The effects of cooking viz. pressure-cooking and broiling and storage at 4 °C for six days and -10 °C for 90 days on lipid oxidation and development of cholesterol oxidation products in mutton were studied. Results revealed that cooking of meat significantly increased the total lipids, phospholipids, cholesterol, glycolipids, free fatty acids and glycerides, but they did not change during refrigerated and frozen storage. The TBA values increased on cooking and during storage. However, the values were below the threshold level for rancidity development. The following cholesterol oxidation products were separated by thin layer chromatography cholestanetriol, 7-α-hydroxy cholesterol, 19-hydroxycholesterol, 7-ketocholesterol, cholesterol-α-epoxide, cholesterol-β-epoxide and an unidentified fraction. All these fractions except the unidentified fraction increased on cooking. On refrigerated and even on frozen storage all these fractions increased except the unidentified fraction, which showed a concomitant reduction. The changes in broiled meat were more pronounced compared to pressure-cooked meat. Results clearly indicated that even frozen storage of cooked meat did not prevent the development of cholesterol oxidation products.     

Veal colour assessment with three wavelengths

A method to derive reflectance spectra and colour coordinates of meat by measurement of reflectance at only three wavelengths, 480, 570 and 620 nm has been developed, by treating the spectra of a meat sample as a linear combination of the spectra of the three major myoglobin derivatives (reduced myoglobin, oxymyoglobin and metmyoglobin). Applied to 300 samples of Semitendinosus and Longissimus dorsi veal muscles at different times post mortem (24 h to 9 d), colour differences ΔE (?) between the derived spectra and the real ones were about 1.5 units. The total pigment content, with high correlation with the extraction method (P < 0.02), and the relative proportions of the derivatives can also be estimated.     

Regulation and Reconstruction of Cell Phenotype Gradients Along the Tendon-Bone Interface

Tendon–bone interface is prevalent in the human body. It is divided into four zones: tendon (soft tissue), unmineralized fibrocartilage, mineralized fibrocartilage, and bone (hard tissue). Tendon–bone interface is characterized by a cell phenotype gradient that appears in the different zones. The cell phenotype gradients at the tendon–bone interface are orchestrated by specific intracellular molecular mechanisms, extracellular factors, immune signals, and neurovascular factors. These features have inspired scientists to design systems that mimic natural cell phenotype gradients. These biomimetic systems include the construction of cell sheets, regulation of cellular microenvironments, and the design of gradient functional scaffolds. Exploration of methods to mimic cell phenotype gradients is instructional for future clinical applications in reconstituting the tendon–bone interface. The present review elucidates the gradient composition of the tendon–bone interface. The associated regulatory mechanisms and applications are discussed, with the anticipation of creating a mise en scène for future research in interface tissue engineering.     

An 8-Bit Digitally Controlled Programmable Phase Shifter Circuit for Sinusoidal Signals with 252∘ Phase Control Range

In this paper, the synthesis, design, and implementation of a programmable phase shifter circuit for sinusoidal signals is presented. The proposed circuit, built-up herein with operational amplifiers (OPAMPs), high precision resistors and low voltage switches, consists of a digitally controlled amplitude attenuator in combination with a single-tone orthogonalizer. Experimental results agree with theoretical background: the attained phase range was 252^° in 256 steps with a median step of 0.9^°. The inaccuracy of the circuit was determined to be of 0.03 %. Contrary to other OPAMP approaches for sinusoidal signals reported in the literature and based on a first-order all-pass filter structure, the approximation suggested in this work is based on a different concept. The achieved results demonstrate the functionality of the system for the case of a sinusoidal signal with frequency of 1 kHz. Notwithstanding, the proposed architecture can be extended to operate at higher frequencies by using different building blocks with larger bandwidth. Furthermore, it can be extended as well to work out with other periodic input waveforms, like triangular shapes or square waves, with the use of an appropriate orthogonalizer.     

Exploration of Electrochemical Reactions at Organic–Inorganic Halide Perovskite Interfaces via Machine Learning in In Situ Time‐of‐Flight Secondary Ion Mass Spectrometry

The instability of hybrid organic–inorganic perovskite (HOIP) devices is one of the significant challenges preventing commercialization. Exploring these phenomena is severely limited by the complexity of the intrinsic electrochemistry of HOIPs, the presence of multiple volatile and mobile ionic species, and the possible role of environmentally induced reactions at surfaces and triple‐phase junctions. Here, in situ studies of the electrochemistry of methylammonium lead bromide perovskite with the Au electrode interface are reported via light‐ and voltage‐dependent time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) imaging of lateral perovskite heterostructures. While ToF‐SIMS allows for the visualization of the chemical composition along the surface and its evolution with light and electrical bias, the interpretation of the multidimensional data obtained is often limited due to strong correlations between chemical signatures and the need to track multiple peaks at once. Here, a machine learning workflow combining the Hough transform and non‐negative matrix factorization and non‐negative tensor decomposition is developed to avoid this limitation and extract salient features of associated chemical changes and to separate the light‐ and voltage‐dependent dynamics. Combining these in situ characterizations and the machine learning workflow provides comprehensive information on the chemical nature of moving species, ion accumulation, and interfacial electrochemical reactions in HOIP devices.     

制药工厂洁净室的压差控制

分析介绍了制药工厂洁净室压差控制的目的和作用以及制药工厂相关规范标准中压差控制的目标要求;结合中国新版GMP中压差控制的要求,对制药工厂洁净室压差控制的方法与措施进行了探讨。     

有机显示浮出水面

介绍了有机显示技术的优势及其应用领域。     

一种分形图像编码的快速算法

分形图像编码是近年来研究十分活跃的一种图像压缩编码方法.在分形图像编码中,由于值块与域块的匹配搜索计算量很大,导致分形编码速度较慢,不能适应图像实时传输的场合.本文分析了值块、域块之间的距离与值块的和值、域块的和值之间的关系,并由此提出了一种分形编码的快速算法.仿真结果表明,使用这种快速分形编码方法,可以减小搜索时间,较大程度地提高分形编码的速度,且解码图像的质量受影响甚少.     

Integration of Stiff Graphene and Tough Silk for the Design and Fabrication of Versatile Electronic Materials

The production of structural and functional materials with enhanced mechanical properties through the integration of soft and hard components is a common approach to Nature's material design. However, directly mimicking these optimized design routes in the lab for practical applications remains challenging. For example, graphene and silk are two materials with complementary mechanical properties that feature ultrahigh stiffness and toughness, respectively. Yet, no simple and controllable approach is developed to homogeneously integrate these two components into functional composites, mainly due to the hydrophobicity and chemical inertness of graphene. In this study, well‐dispersed and highly stable graphene/silk fibroin (SF) suspension systems are developed, which are suitable for processing to fabricate polymorphic materials, such as films, fibers, and coatings. The obtained graphene/SF nanocomposites maintain the electronic advantages of graphene, and they also allow tailorable mechanical performance to form including ultrahigh stretchable (with a strain to failure to 611 ± 85%), or high strength (339 MPa) and high stiffness (7.4 GPa) material systems. More remarkably, the electrical resistances of these graphene/SF materials are sensitive to material deformation, body movement, as well as humidity and chemical environmental changes. These unique features promise their utility as wearable sensors, smart textiles, intelligent skins, and human–machine interfaces.     

更换旧蓄电池组应注意的安全问题

先期使用的大批阀控式密封铅酸蓄电池(VRLA电池),及固定型防酸隔爆式铅酸蓄电池(GGF电池)由于各种原因容量下降,不能保证其正常使用需进行更换。本文对如何安全可靠进行新旧蓄电池组的更换割接提出建议。