BK Polyomavirus bkv-miR-B1-5p: A Stable Micro-RNA to Monitor Active Viral Replication after Kidney Transplantation

Background: Bkv-miR-B1-5p is a viral micro-RNA (miRNA) specifically produced during BK polyomavirus (BKPyV) replication. Recent studies have suggested using bkv-miR-B1-5p as a biomarker to monitor viral infection and predict complications in kidney transplant patients. To identify the technical limitations of this miRNA quantification in biological samples, knowledge of its stability and distribution in the extracellular compartment is necessary. Moreover, a proof of concept for using bkv-miR-B1-5p as a biomarker of active replication in chronic infection is still missing in the published literature. Methods: The stability of bkv-miR-B1-5p was evaluated in samples derived from cell cultures and in urine from BKPyV-infected kidney transplant recipients. The miRNA was quantified in different fractions of the extracellular compartment, including exosomes, and protein binding was evaluated. Finally, we developed an in vitro model for chronic culture of BKPyV clinical isolates to observe changes in the bkv-miR-B1-5p level during persistent infections. Results: Bkv-miR-B1-5p is a stable biomarker in samples from humans and in vitro experiments. Marginally associated with the exosomes, most of the circulating bkv-miR-B1-5p is bound to proteins, especially Ago2, so the miRNA quantification does not require specific exosome isolation. The bkv-miR-B1-5p level is predictable of viral infectivity, which makes it a potential specific biomarker of active BKPyV replication after kidney transplantation.     

反转构造的反转程度及其与油气聚集的关系

结合典型反转构造地震剖面，分析了断层型和褶皱型两类反转构造的反转程度，上下皆正断层型和向形褶皱型反转构造的反转程度轻微；上逆下正断层型和透镜形褶皱型反转构造的反转程度中等；上下皆逆断层型和背形褶皱型反转构造的反转程度强烈。分析了反转构造的反转程度与油气聚集的关系，处于轻微反转程度的上下皆正断层型反转和向形褶皱型反转，以及处于强烈反转程度的上下皆逆断层型反转和背形褶皱型反转不利于油气聚集；处于中等反转程度的上逆下正断层型反转和透镜形褶皱型反转类型有利于油气聚集成藏。     

Benchmarking of lightweight cryptographic algorithms for wireless IoT networks

Wireless Networks - Cryptographic algorithms that can provide both encryption and authentication are increasingly required in modern security architectures and protocols (e.g. TLS v1.3). Many...     

一种新颖的跳频振荡器

摘要本文综合考虑到频率合成技术及单端口体波谐振器HBAR的特点提出了一种基于一阶非线性PLL的锁相频率合成方案。文中对这种跳频方案的原理、性能特点作了详细论述、并通过实验、从不同角度对本方案进行了说明、同时对整机的各项指标作了详尽测试:在HBAR无载Q_N值为4000的情况下,该多模跳频振荡源的捷变范围为770MHz—840MHz、捷变时间小于20μS。杂散分量低于—60dB、二次谐波分量低于—34dB。离散捷变频率点为16点,构成闭环跳频系统后,对开环VCO的短稳改善了三个量级:从1.3×10~(-5)/ms到1.6×10~(-8)/ms及9.56×~(-7)/s到1.69×!0~(-9)/s,尤为重要的是该多模跳频振荡源达到此性能所需的硬件量很小,因此在对体积要求苛刻的场合、此种跳频方案具有极强的竞争力。     

A Single Bout of Ultra-Endurance Exercise Reveals Early Signs of Muscle Aging in Master Athletes

Middle-aged and master endurance athletes exhibit similar physical performance and long-term muscle adaptation to aerobic exercise. Nevertheless, we hypothesized that the short-term plasticity of the skeletal muscle might be distinctly altered for master athletes when they are challenged by a single bout of prolonged moderate-intensity exercise. Six middle-aged (37Y) and five older (50Y) master highly-trained athletes performed a 24-h treadmill run (24TR). Vastus lateralis muscle biopsies were collected before and after the run and assessed for proteomics, fiber morphometry, intramyocellular lipid droplets (LD), mitochondrial oxidative activity, extracellular matrix (ECM), and micro-vascularisation. Before 24TR, muscle fiber type morphometry, intramyocellular LD, oxidative activity, ECM and micro-vascularisation were similar between master and middle-aged runners. For 37Y runners, 24TR was associated with ECM thickening, increased capillary-to-fiber interface, and an 89% depletion of LD in type-I fibers. In contrast, for 50Y runners, 24TR did not alter ECM and capillarization and poorly depleted LDs. Moreover, an impaired succinate dehydrogenase activity and functional class scoring of proteomes suggested reduced oxidative phosphorylation post-24TR exclusively in 50Y muscle. Collectively, our data support that middle-aged and master endurance athletes exhibit distinct transient plasticity in response to a single bout of ultra-endurance exercise, which may constitute early signs of muscle aging for master athletes.     

Identification of ritual blood in African artifacts using TOF-SIMS and synchrotron radiation microspectroscopies

A new protocol is implemented to demonstrate the presence of blood in the patina of African art objects from Mali. Divided into three steps, the protocol first consists in demonstrating the presence of proteins and localizing them in the sample's cross sections using time-of-flight secondary ion mass spectrometry (TOF-SIMS) and synchrotron-based infrared microspectrometry (microFT-IR). In a second time, TOF-SIMS is used to investigate heme, which is a blood marker. If heme is missing, which could mean that it is too degraded to be detected, X-ray microfluorescence (microXRF) and X-ray absorption near-edge microspectroscopy (microXANES) are used to prove the presence of iron in the protein area and to get a fingerprint of its chemical environment. This permits us thus to demonstrate that iron is indeed linked with proteins and not with mineral phases of the sample. Coupled with the ritual context of the objects, this constitutes a proof of the use of blood. Thanks to this protocol, which has the major advantage of avoiding false positive results, the presence of blood has been demonstrated in seven out of the eight studied samples.     

一种推广的自适应相干累积算法—基本原理与应用

本文提出一种推广的自适应相干累积（GACI）算法，它是通过在自适应相干累积（ACI）算法权系数迭代公式中引入更多的动量因子，即利用权系数更多的历史信息，使被检测的单频或调频脉冲信号，在脉冲持续期间，实现自适应相干累积，从而完成弱输入信噪比（如-8dB）条件下的信号检测，而无需或很少需要知道信号的先验信息，文中叙述了算法的基本原理及部分典型的实时实验结果，指出GACI算法具有比ACI算法更好的提取弱信号的能力，预计将有广泛的实际应用前景。     

On the origin of the blue/green color of blast‐furnace slag‐based materials: Sulfur K‐edge XANES investigation

Slag‐based materials including mortars, concretes, Ca‐geopolymers, etc., are known to display a fascinating blue/green color upon hydration. This specific color is of particular concern in applications where visual esthetics are important. Yet only limited studies have been devoted to this phenomenon so far and its origin remains unexplained. It has sometimes been attributed, without any experimental evidence, to the presence of polysulfur species in the slag. To address the origin of this coloration, sulfur K‐edge X‐ray absorption near edge structure (XANES) spectroscopy was used to investigate the evolution of the speciation of sulfur during slag hydration. Three methods of slag activation were considered: thermal, portland cement, and sodium silicate. The impact of the activation method on the sulfur K‐edge XANES spectrum was examined first. Then, a comparison was made between the XANES of blue and white samples or zones with or without the blue color within the same sample. Independently of the activation route, the blue color was found to be unambiguously related to the presence of a prepeak in the corresponding XANES spectrum. This feature was absent for white samples or white zones. The prepeak, which was located at lower energy than the peak corresponding to the most common reduced sulfur species, was attributed to the presence of the trisulfur radical anion S₃^?. This blue chromophore is known to be at the origin of the deep blue color of the stone lapis lazuli or the ultramarine pigment (derived from lazurite).     

Claramines: A New Class Of Broad‐Spectrum Antimicrobial Agents With Bimodal Activity

The emergence of multidrug‐resistant bacteria and pathogens has created an urgent need for the development of new antibiotics. Herein we report our investigations into the broad‐spectrum activity of an easily prepared water‐soluble polyaminosterol compound, namely claramine A1, against both drug‐sensitive and drug‐resistant Gram‐negative and Gram‐positive bacterial strains. We also report its peculiar mechanism of action, which differs from that of all the other well‐known classes of antibiotics, toward Gram‐negative and Gram‐positive bacteria. Given their low cytotoxicity, this class of compounds based on claramine A1 could constitute an effective response to combat the emergence of multidrug‐resistant bacteria and nosocomial diseases.     

舰船冷却设备的防腐对策

针对舰船用海水冷却设备的腐蚀情况的调查，提出了 基本的舰用冷却设备的腐蚀控制原则，并论述了电绝缘措施控制电偶腐蚀、非金属复合层保 护、牺牲阳极和外加电流阴极保护等几种防腐方法，实践证明通过对冷却设备采用本文中提 出的防腐措施，可以很好的解决舰船冷却设备的腐蚀防护问题.