Antifreeze Proteins: Novel Applications and Navigation towards Their Clinical Application in Cryobanking

Antifreeze proteins (AFPs) or thermal hysteresis (TH) proteins are biomolecular gifts of nature to sustain life in extremely cold environments. This family of peptides, glycopeptides and proteins produced by diverse organisms including bacteria, yeast, insects and fish act by non-colligatively depressing the freezing temperature of the water below its melting point in a process termed thermal hysteresis which is then responsible for ice crystal equilibrium and inhibition of ice recrystallisation; the major cause of cell dehydration, membrane rupture and subsequent cryodamage. Scientists on the other hand have been exploring various substances as cryoprotectants. Some of the cryoprotectants in use include trehalose, dimethyl sulfoxide (DMSO), ethylene glycol (EG), sucrose, propylene glycol (PG) and glycerol but their extensive application is limited mostly by toxicity, thus fueling the quest for better cryoprotectants. Hence, extracting or synthesizing antifreeze protein and testing their cryoprotective activity has become a popular topic among researchers. Research concerning AFPs encompasses lots of effort ranging from understanding their sources and mechanism of action, extraction and purification/synthesis to structural elucidation with the aim of achieving better outcomes in cryopreservation. This review explores the potential clinical application of AFPs in the cryopreservation of different cells, tissues and organs. Here, we discuss novel approaches, identify research gaps and propose future research directions in the application of AFPs based on recent studies with the aim of achieving successful clinical and commercial use of AFPs in the future.     

A class of band-limited chip waveforms for DS-CDMA systems

In Direct Sequence Code Division Multiple Access （DS-CDMA） systems, the chip waveform affects the implementation, system bandwidth, envelope uniformity, eye pattern and Multiple user Access Interference （MAI）. In this paper, based on an elementary density function of a second order polynomial, a class of second order continuity pulses is proposed. From this class of pulses, we can find some members having faster decaying rate, bigger eye opening, more uniform envelope and stronger anti-MAI capability than the Nyquist waveform. The normalized-bandwidth-pulseshape-factor product, the decaying rate of the tail of the time waveform, the opening of the eye diagram, and the envelope uniformity of the second order continuity pulses are addressed in the paper that provide the basic information for the selection of the chip pulse for CDMA systems.     

基于MAX262的可程控多频点带通滤波器的设计

基于可编程开关电容有源滤波器MAX262可通过改变外部时钟频率以及采用微处理器接口控制64级中心频率这一特性,给出了一种滤波器设计新方法,采用一个时钟频率,实现了多频点的带通滤波,WAVE仿真结果达到了设计的要求。     

Arbuscular mycorrhizal symbiosis facilitates apricot seedling(Prunus sibirica L.) growth and photosynthesis in northwest China

Arbuscular mycorrhizal (AM) fungi can successfully enhance photosynthesis (Pn) and plants growth in agri-cultural or grassland ecosystems.However,how the symbio...     

热活化过硫酸盐降解典型选矿药剂苯甲羟肟酸的研究

采用热活化过硫酸钾(PS)降解典型选矿药剂苯甲羟肟酸(BHA),考察不同温度、PS浓度、BHA浓度、pH及阴阳离子等条件对BHA降解效果的影响,分析降解产物及体系活性物种以明确体系降解机理,并通过绿豆芽发芽试验验证降解体系毒性变化。实验结果表明：PS浓度越高,温度越高降解效果越好,在70°C及1.5 mmol/L PS的条件下,反应120 min后,20 mg/L BHA的降解率达91.34%;强酸性和强碱性条件均能促进BHA的降解;HCO3-^、SiO32-^和Cu2+^促进了BHA的去除;降解过程以SO4.-^氧化为主.热活化PS降解BHA的主要中间产物为苯甲酸和羟胺,且Cu²⁺的存在促进了羟胺到气态氮的转化。绿豆发芽试验证明经降解后的反应体系毒性较原始溶液明显下降。     

Layer-dependent charge density wave phase transition stiffness in 1T-TaS2 nanoflakes evidenced by ultrafast carrier dynamics

Novel physical properties emerge when the thickness of charge density wave(CDW)materials is reduced to the atomic level,owing to the significant modification of the electronic band structure and correlation effects.Here,we investigate the layer-dependent CDW phase transition and evolution of the nonequilibrium state of 1T-TaS₂nanoflakes using pump-probe spectroscopy.Both the low-energy single-particle and collective excitation relaxations exhibit sharp changes at?210 K,indicating a phase transition from commensurate CDW to nearly commensurate CDW state.The single particle process reveals that the phase transition stiffness(PTS)is thickness-dependent.Moreover,a small PTS is observed in thin nanoflakes,which is attributed to the reduced thickness that increases the fluctuation and inhibits the nucleation and growth of discommensurations.In addition,the phase mode vanishes when the discommensuration network appears.Our results suggest that the carrier dynamics could be an efficient operational approach to measuring the quantum phase transition in correlated materials.     

In-plane heterostructured Ag2S-In2S3 atomic layers enabling boosted CO2 photoreduction into CH4

Nano Research - Sluggish separation and migration kinetics of the photogenerated carriers account for the low-efficiency of CO2 photoreduction into CH4. Design and construction two-dimensional (2D)...     

Identifying the convergent reaction path from predesigned assembled structures: Dissymmetrical dehalogenation of Br2Py on Ag(111)

Nano Research - On-surface Ullmann coupling has been intensely utilized for the tailor-made fabrication of conjugated frameworks towards molecular electronics, however, reaction mechanisms are...     

Static recrystallization behavior of SA508Gr.4N reactor pressure vessel steel during hot compressive deformation

The two-pass isothermal hot compression method was used to study the effect of different thermal deformation conditions on static recrystallization behavior in ...     

Electrochemical performance of nanostructured amorphous Co3Sn2 intermetallic compound prepared by a solvothermal route

A nanostructured amorphous Co₃Sn₂ intermetallic compound was prepared by a solvothermal route. The microstructure and the electrochemical performance were studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), galvanostatic cycling, and ex situ XRD. It was found that the as-prepared material is in nanoscale and is amorphous. The amorphous Co₃Sn₂ shows a first specific capacity of 363 mA h g⁻¹ compared to 92 mA h g⁻¹ for the crystalline one prepared by annealing the amorphous material. Ex situ XRD investigation shows that the amorphous Co₃Sn₂ undergoes a crystallization process during cycling, which leads to the capacity fade.