Effect of calcination temperature on morphology,crystallinity and electrochemical properties of nano-crystalline metal oxides (Co3O4, CuO,and NiO) prepared via ultrasonic spray pyrolysis

Nano-crystalline metal oxides (Co₃O₄, CuO, and NiO) are synthesized as anode materials for lithium-ion batteries by an ultrasonic spray pyrolysis method. The effects of calcination temperature on the morphology, crystallite size and electrochemical properties of the metal oxides are investigated. X-ray diffraction (XRD) studies show that the crystallite size varies with the final calcination temperature. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations reveal that the calcination temperature strongly influences the morphology of the prepared metal oxides and this results in different electrochemical performance. The existence of a nano-scale microstructure for the prepared metal oxides has a strong relationship with irreversible capacity and capacity retention.     

End Effect on the Twin—Wire Depth Probe

The end effect on the output voltage of a twin-wire depth probe was investigated both theoretically and ex-perimentally.It was found that the contribution of the end of the probe to the output voltage depends uponthe distance between the boundary and the end of the probe and the geometrical configuration of the probe.By mounting a piece of plate to the end of the electrodes,the end effect can be reduced.However,the size ofthe plate required to eliminate completely this effect is much larger than that usually mounted on commerciallyavailable probes.Comparison between theoretical and experimental results was made.Reasonable agreementwas obtained.     

Multifunctional encoded self-assembling protein nanofibrils as platform for high-throughput and multiplexed detection of biomolecules

A one-dimensional nanofibrillar array formed by the co-assembly of native and biotin-functionalized beta-amyloid (Aβ) peptide was developed for biomolecule sensing. With the presence of biotin moiety, a variety of biomolecular probes can be conjugated onto the nanofibrils, thus converting the protein assembly into a miniature biosensor. In this work, DNA probes were immobilized onto the fibril for the detection of cDNA sequences. The as-developed "DNA-nanoarray" achieved a detection limit at subattomole level (183 fM in 10 μL). This highly sensitive, yet simple, assay requires a trace amount of sample consumption (<10 μL) and is pretreatment-free. In addition, we reported the preparation of alternate-segmented amyloid nanofibrils with multifunctionality. The fibrils hereby serve as an encoded template that can be visualized with various fluorescence labeling dyes for barcode recognition purpose, and, hence, multiplex detection of biomolecules was achieved. Regarding that each protein nanofibril represents a single detection platform, a large number of single fibrils simultaneously are monitored with the dual-color TIRFM in a high-throughput manner.     

Engineered Amp C β-lactamase as a fluorescent screening tool for class C β-lactamase inhibitors

Class C β-lactamases mediate antibiotic resistance in bacteria by efficiently hydrolyzing a broad range of β-lactam antibiotics. With their clinical significance and the lack of commercially available effective inhibitors, development of class C β-lactamase inhibitors has become one of the recent hot issues in the pharmaceutical industry. In this paper, we report the protein engineering of a fluorescent Amp C β-lactamase mutant designated as V211Cf for the in vitro screening of class C β-lactamase inhibitors. When a fluorescein (f) was incorporated at the entrance of the enzyme's active site (position 211), Amp C β-lactamase from Enterobacter cloacae P99 was tailor-made into a novel fluorescent biosensing protein that could display a fluorescence enhancement upon binding with its β-lactam substrates/inhibitors. With its catalytic activity close to the wild-type level, V211Cf can act as a "natural" fluorescent drug target for screening small binding molecules. In addition, V211Cf can allow specific detection for its active-site binding molecules and discriminate them from nondruglike molecules in the screen. Furthermore, V211Cf is amenable to a high throughput format. Taken together, V211Cf demonstrates the potential as an efficient tool for screening class C β-lactamase inhibitors and facilitates the discovery of therapeutics that can combat the clinically important class C β-lactamases.     

Relationship between types of surface shear stress profiles and membrane fouling

Shear stress has been recognized as an important parameter in controlling particle back-transport from membrane surfaces. However, little is known of the relationship between transient shear conditions induced by air sparging and fouling control near membrane surfaces. In this paper, the different types of surface shear stress profiles that had beneficial effects on minimizing reversible surface fouling were examined. The relationship between different statistical shear parameters (e.g. time-averaged shear, standard deviation of shear and amplitude of shear) and fouling control that have been used by others were examined as well. It was found that the fouling rate for membranes subjected to transient shear conditions was lower than for membranes subjected to constant shear conditions. The magnitude, duration and frequency of the shear conditions were found to have an impact on the fouling rate of membranes. It was also found that although some statistical shear parameters could generally be used to relate shear and fouling, they were inadequate to relate surface shear stress to fouling, for all transient shear conditions examined.     

广域复杂流体系统中基于无线传感网的数据保存关键技术研究进展

流体系统包括城市供水管网、天然气供给管网等,是具有经济和社会价值的重要基础设施。它们具有分布地域广、结构复杂、规模庞大、难以检测等特点,在出现泄漏、污染等异常时难以快速发现和准确定位。随着传感器技术、通信技术、微机电技术等的发展,利用无线传感网来对系统进行监测成为研究热点。由于在流体系统中通信困难,数据被监测到后很难实时传送给用户,只能暂时保存在传感器节点(简称节点)上,等待适当的时刻再进行上传。但是,节点具有体积微小、易损坏、存储容量小、通信能力弱、能量有限等特点,如何可靠地存储大量的数据是一个难点问题。目前,已有部分工作对这个问题进行了研究。为了解该领域研究的进展,文中对相关工作进行了细致地分析、对比、归纳和总结,介绍了它们的优缺点,并对未来的研究方向进行了探讨。     

Fluid Biomarkers in HPV and Non-HPV Related Oropharyngeal Carcinomas: From Diagnosis and Monitoring to Prognostication—A Systematic Review

Biomarkers are crucial in oncology, from detection and monitoring to guiding management and predicting treatment outcomes. Histological assessment of tissue biopsies is currently the gold standard for oropharyngeal cancers, but is technically demanding, invasive, and expensive. This systematic review aims to review current markers that are detectable in biofluids, which offer promising non-invasive alternatives in oropharyngeal carcinomas (OPCs). A total of 174 clinical trials from the PubMed search engine in the last 5 years were identified and screened by 4 independent reviewers. From these, 38 eligible clinical trials were found and subsequently reviewed. The biomarkers involved, categorized by human papillomavirus (HPV)-status, were further divided according to molecular and cellular levels. Recent trials investigating biomarkers for both HPV-positive and HPV-negative OPCs have approaches from various levels and different biofluids including plasma, oropharyngeal swabs, and oral rinse. Promising candidates have been found to aid in detection, staging, and predicting prognosis, in addition to well-established factors including HPV-status, drinking and smoking status. These studies also emphasize the possibility of enhancing prediction results and increasing statistical significance by multivariate analyses. Liquid biopsies offer promising assistance in enhancing personalized medicine for cancer treatment, from lowering barriers towards early screening, to facilitating de-escalation of treatment. However, further research is needed, and the combination of liquid biopsies with pre-existing methods, including in vivo imaging and invasive techniques such as neck dissections, could also be explored in future trials.     

EGFR T751_I759delinsN Mutation in Exon19 Detected by NGS but Not by Real-Time PCR in a Heavily-Treated Patient with NSCLC

The detection of driver gene mutations can determine appropriate treatment strategies for non-small cell lung cancer (NSCLC) by identifying the presence of an effective druggable target. Mutations in the gene encoding the epidermal growth factor receptor (EGFR) are common driver mutations in NSCLC that can be effectively targeted by the use of EGFR tyrosine kinase inhibitors (EGFR-TKIs). However, without the detection of driver mutations, appropriate therapeutic decisions cannot be made. The most commonly applied methods for detecting driver gene mutations are assays based on polymerase chain reaction (PCR). However, the underlying mechanism of PCR-based assays limits the detection of rare mutations. Therefore, patients harboring rare mutations may not receive optimal treatment. We report a heavily-treated patient with NSCLC who harbored a T751_I759delinsN mutation in exon 19 of EGFR that was not detected by real-time PCR but was successfully detected by next-generation sequencing (NGS). The detection of a driver mutation using NGS resulted in the administration of targeted therapy, leading to favorable progression-free survival for the patient. Our report highlights the importance and potential of routine NGS testing among NSCLC patients for whom traditional assays fail to detect driver mutations when determining treatment options.     

Genome-Wide Identification and Expression Patterns of the SWEET Gene Family in Bletilla striata and its Responses to Low Temperature and Oxidative Stress

SWEETs (sugars will eventually be exported transporters), a well-known class of sugar transporters, are involved in plant growth and development, sugar transport, biotic and abiotic stresses, etc. However, to date, there have been few investigations of SWEETs in Orchidaceae. In this study, 23 SWEET genes were identified in Bletilla striata for the first time, with an MtN3/saliva conserved domain, and were divided into four subgroups by phylogenetic tree. The same subfamily members had similar gene structures and motifs. Multiple cis-elements related to sugar and environmental stresses were found in the promoter region. Further, 21 genes were localized on 11 chromosomes and 2 paralogous pairs were found via intraspecific collinearity analysis. Expression profiling results showed that BsSWEETs were tissue-specific. It also revealed that BsSWEET10 and BsSWEET18 were responsive to low temperature and oxidative stresses. In addition, subcellular localization study indicated that BsSWEET15 and BsSWEET16 were localized in the cell membrane. This study provided important clues for the in-depth elucidation of the sugar transport mechanism of BsSWEET genes and their functional roles in response to abiotic stresses.     

SHMT2 Induces Stemness and Progression of Head and Neck Cancer

Various enzymes in the one-carbon metabolic pathway are closely related to the development of tumors, and they can all be potential targets for cancer therapy. Serine hydroxymethyltransferase2 (SHMT2), a key metabolic enzyme, is very important for the proliferation and growth of cancer cells. However, the function and mechanism of SHMT2 in head and neck cancer (HNC) are not clear. An analysis of The Cancer Genome Atlas (TCGA) data showed that the expression of SHMT2 was higher in tumor tissue than in normal tissue, and its expression was significantly associated with male sex, aggressive histological grade, lymph node metastasis, distant metastasis, advanced TNM stage, and lymphovascular invasion in HNC. SHMT2 knockdown in FADU and SNU1041 cell lines significantly inhibited cell proliferation, colony formation, migration, and invasion. Additionally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses using TCGA data revealed that SHMT2 was closely related to cancer stem cell regulation and maintenance. Furthermore, we found that silencing SHMT2 inhibited the expression of stemness markers and tumor spheroid formation compared with a control group. On the contrary, stemness markers were significantly increased after SHMT2 overexpression in HEP-2 cells. Interestingly, we found that knocking down SHMT2 reduced the expression of genes related to the Notch and Wnt pathways. Finally, silencing SHMT2 significantly reduced tumor growth and decreased stemness markers in a xenograft model. Taken together, our study suggests that targeting SHMT2 may play an important role in inhibiting HNC progression.