Search

Purpose This paper aims to give an overview about the state of wireless passive surface acoustic wave (SAW) gas sensor used in the detection of chemical vapor. It also discusses a variety of different architectures including delay line and array sensor for gas detection, and it is considered that this technology has a good application prospect. Design/methodology/approach The authors state the most of the wireless passive SAW methods used in gas sensing, such as CO2, CO, CH4, C2H4, NH3, NO2, et al., the sensor principles, design procedures and technological issues are discussed in detail; their advantages and disadvantages are also summarized. In conclusion, it gives a prospect of wireless passive SAW sensor applications and proposes the future research field might lie in the studying of many kinds of harmful gases. Findings In this paper, the authors will try to cover most of the important methods used in gas sensing and their recent developments. Although wireless passive SAW sensors have been used successfully in harsh environments for the monitoring of temperature or pressure, the using in chemical gases are seldom reported. This review paper gives a survey of the present state of wireless passive SAW sensor in gas detection and suggests new and exciting perspectives of wireless passive SAW gas sensor technology. Research limitations/implications The authors will review most of the methods used in wireless passive SAW sensor and discuss the current research status and development trend; the potential application in future is also forecasted. Originality/value The authors will review most of the methods used in wireless passive SAW sensor and discuss the current research status and development trend; the potential application in future is also forecasted.

A workable approach named xTB-sTDDFT was selected to investigate the excited-state spectra of oxytocin (135 atoms), GHRP-6 (120 atoms) and insulin (793 atoms). Three different Hartree–Fock components functionals (wB97XD3: 51%, LC-BLYP: 53%, wB97X: 57%) were used to calculate the excitation spectra, and the results calculated by wB97XD3 functional well agree with the experiments. It’s a deep impression that computed time cost reduced by more than 80%. For polypeptide (oxytocin and GHRP-6), both UV and fluorescence spectra were obtained, and the errors between the calculated and experimental values approximately were 20 nm. For Insulin, the errors are within 15 nm. UV spectrum peak is λcal = 262 nm (λexp = 277 nm, Δλ = 15 nm), and fluorescence spectrum peak is λcal = 294 nm (λexp = 304 nm, Δλ = 10 nm). In summary, a suitable theoretical model is established to ultra-fast calculate the electronic excitation spectra of large systems, such as proteins and biomacromolecules, with good calculation accuracy, fast calculation speed and low cost.

Three-dimensional excitation emission matrix (EEM) fluorescence spectroscopy was employed to discriminate protein samples comprising bovine serum albumin, neurotensin, ovalbumin, ricin, trypsin from bovine pancreas and trypsin from porcine pancreas. Two methods of feature extraction with and without parameterization were applied to the spectral data in order to evaluate their performance of discrimination between protein samples. The discrimination of protein samples was conducted by k-means clustering algorithm and eigenvalue extracting procedure based on principal component analysis (PCA). It was found that the method of feature extraction without parameterization performed best, correctly attributing 100% of the spectral data in the condition of two principal components (PCs) captured. Features extracted with spectral parameterization failed to separate ricin and trypsin from bovine pancreas in same condition. Without spectral parameterization, less dimensionality and unique principal components captured by PCA indicates the spectrally-resolved features of corresponding protein samples. By clustering using each spectrum at fixed excitation wavelength, excitation wavelengths matched with common intrinsic fluorophores were found to be more sensitive to the classification accuracy. Contributions of spectral features extracted from EEM to the principal components were discussed and demonstrated their feature differentiation capabilities among six protein samples. These results reveal that appropriate extraction approach of features in combination with PCA analysis could be used in discrimination of protein samples at species level as a spectroscopic diagnostic tool. Our study provides fundamental references about computational strategies when EEM are used to explore proteins in ambient environment.

The uniformity and compactness of the surface of a viscoelastic sensitive film are among the most important factors that influence the characteristics of a surface acoustic wave (SAW) gas sensor, directly affecting the detection sensitivity of a SAW sensor on a target gas. In this paper, poly(epichlorohydrin) (PECH) with viscoelastic properties was used as sensitive film for the detection of 2-chloroethyl ethyl sulfide (CEES), a common simulant of the chemical agent mustard gas. Nanoscale films were prepared using a spin coating technology on a SAW delay line of 200 MHz. Films were evaluated using polarizing microscopy and atomic force microscopy and observed with uniform surface states and particle diameter in the cluster region of 4.52-5.22 μm. The interface parameters, including contact angle, surface tension, Gibbs free energy, work of adhesion, work of immersion, and spreading coefficient values were 9.31° to 39.63°, 22.475 to 29.945 mN m

A simple composition of TeO2–Yb2O3 binary glass was selected as the host glass matrix for discussing the structure of tellurite glass with increasing Yb2O3 content. Raman spectra were measured to investigate the structure of the binary tellurite glasses, and upconversion and downconversion fluorescence characteristics were employed for discussing the relationship between the structural units and the state of Yb3+ in the tellurite glasses. The results suggested that the decrease of TeO4/2 in the glasses would result in the formation of Yb3+ clusters and Yb3+–O2− couple in the tellurite glasses, and then results in the decrease of cooperative upconversion and downconversion fluorescence intensity.

In this study, diisopropyl methylphosphonate (DIMP), tributyl phosphate (TBP), and dimethyl methylphosphonate (DMMP) were selected as organophosphorus chemical warfare agent (CWA) simulants. An effective surface acoustic wave (SAW) array sensor coated with three self-assembled imprinted supramolecular films and two polymer coatings was prepared to detect CWA simulants at low concentrations. As a supramolecular film, 25-(thioalkyl-alkoxy)-p-tertbutylcalix[4]arene was synthesized via a two-step nucleophilic substitution reaction in the NaH–THF phase with p-tertbutylcalix[4]arene and dibromodecane. Then, 25-(thioalkyl-alkoxy)-p-tertbutylcalix[4]arene, 1,7,13,20-four-(thioalkyl-alkoxy)-resorcin[4]arene, and mono[6-deoxy-6-[(mercaptodecamethylene)thio]]-β-CD were coated on SAW gold delay lines using a self-assembly method to detect DIMP, DMMP, and TBP, respectively, proving the imprinting effect. The response frequency shifted to DIMP and exhibited a linear relationship in the concentration range of 0.05–0.60 mg m−3. The sensitivity of the SAW sensor was also examined at different temperatures, and the possible mechanism of interactions between the supramolecular coatings and DIMP was discussed. To further prove the effect of supramolecular films, a SAW array sensor was prepared with supramolecular 25-(thioalkyl-alkoxy)-p-tertbutylcalix[4]arene, mono[6-deoxy-6-[(mercaptodecamethylene)thio]]-β-CD, 1,7,13,20-four-(thioalkyl-alkoxy)-resorcin[4]arene, and polymers fluoroalcoholpolysiloxane (SXFA) and poly(epichlorohydrin) (PECH) for detecting DIMP, DMMP, TBP, and 2-chloroethyl ethyl sulfide. The results indicated that the fabricated SAW array sensor was highly sensitive to CWAs and may be used to distinguish CWAs and their related compounds. In the three supramolecular self-assembled imprinted coatings, the aging experiments proved that the response of the SAW array sensor may decrease to approximately 23%, 11%, and 17% after 18 months of storage.

A workable approach named xTB-sTDDFT was selected to investigate the excited-state spectra of oxytocin (135 atoms), GHRP-6 (120 atoms) and insulin (793 atoms). Three different Hartree-Fock components functionals (wB97XD3: 51%, LC-BLYP: 53%, wB97X: 57%) were used to calculate the excitation spectra, and the results calculated by wB97XD3 functional well agree with the experiments. It's a deep impression that computed time cost reduced by more than 80%. For polypeptide (oxytocin and GHRP-6), both UV and fluorescence spectra were obtained, and the errors between the calculated and experimental values approximately were 20 nm. For Insulin, the errors are within 15 nm. UV spectrum peak is λ

Using Gaussian and Orca, UV and fluorescence spectra of three amino acids (Tyr: Tyrosine, Trp: Tryptophan, Phe: Phenylalanine) were calculated by different functionals (B3LYP, BP86, wB97X). The spectra calculated by BP86 are consistent with the experiments. UV spectra peak of Tyr is 255 nm (Exp. 275 nm, Δλ = 20 nm), Trp is 279 nm (Exp. 277 nm, Δλ = 2 nm), and Phe is 275 nm (Exp. 257 nm, Δλ = 18 nm). Fluorescence spectra peak of Trp is 341 nm (Exp. 350 nm, Δλ = 9 nm), Tyr is 295 nm (Exp. 306 nm, Δλ = 11 nm), and Phe is 285 nm (Exp. 302 nm, Δλ = 17 nm). Moreover, a theoretical model for calculating the excited states of biomolecules is established. Compared with Gaussian’s results, Orca is more quickly and effectively for calculating excited state spectra with the same accuracy.

T cell acute lymphoblastic leukemia (T-ALL) is one of the most frequent hematologic malignancies resulted from gene mutations and/or genomic rearrangements that occur in T cell progenitors. The 5-year survival rate of T-ALL patients is less than 50%. Much efforts have been dedicated to decipher the molecular events underlying TALL transformation, with the goals to identify specific therapeutic targets and develop new and more effective drugs. As a member of JAK kinase family, JAK3 mutations can be identified in 16.1% of T-ALL cases, and JAK3 M511I mutation is the most common one within all JAK3 mutations. Activating JAK3 M511I mutation induced a lympho-proliferative disorder, that followed by a T-ALL-like disease. PHF6 mutation is one of the most common co-existing gene mutations with JAK3 in T-ALL patients. Co-mutation events of JAK3 and PHF6 account for 1.89%-10.0% in T-ALL cases. However, the role(s) of PHF6 and JAK3 co-mutations in tumorigenesis is unknown. Here in this study, we first analyzed the genetic data of 449 T-ALL cases from multiple clinical centers in which JAK/STAT mutations is about 21% of the total cases. Interestingly, we found that PHF6 mutations were significantly associated with JAK3 mutations in these T-ALL cases (P To investigate the underlying molecular mechanisms of Phf6 in accelerating T-ALL development,we performed RNAseq to analyze the transcriptome programing changes associated with Phf6 in isogenic Phf6WT +JAK3M511I or Phf6KO +JAK3M511IT-ALL cells. Gene set enrichment analysis (GSEA) showed up-regulated cell cycle in Phf6 KO +JAK3 M511I leukemia cells. We then performed Chromatin immunoprecipitation sequencing (ChIP-seq) and found that PHF6 associated with BAI1 gene. qPCR and Western blot showed that the mRNA and protein expression of Bai1/BAI1 were significantly decreased in Phf6KO +JAK3M511Icells in comparison with Phf6 WT+JAK3M511I cells. BAI1 has been reported to prevent MDM2-mediated P53 ubiquitination, and loss of BAI1 reduces P53 level. We found that the protein expression of BAI1 and P53 was decreased, and the ubiquitination of P53 was significantly increased in PHF6 knockdown (KD) MOLT-4 cells (T-ALL) when compared with the control cells. BAI1 overexpression in PHF6 KD MOLT-4 cells significantly increased P53 expression in PHF6 KD+BAI1 OE MOLT-4 cells when compared with that of PHF6 KD cells. It suggested that Phf6 deficiency increased BAI1-mediated P53 degradation. To confirm this, we treated Phf6 KO + JAK3M511I mice with a JAK3 inhibitor (ruxolitinib) in combination with a MDM2 inhibitor (idasanutlin), and found a synergistic response of the treatment within a significant attenuation in leukemia burden in vivo. In conclusion, we found that PHF6 mutation frequently co-existed with JAK3 mutation in T-ALLs, and together they can drive an aggressive leukemia in mice model. Notably, PHF6 deficiency promoted JAK3-induced T-ALL progression by inhibiting BAI1-MDM2-P53 signaling pathway that is independent of JAK3-STAT signaling pathway. We further demonstrated that combination therapy by tofacitinib and idasanutlin can reduce the Phf6 KO and JAK3 M511I leukemia burden in vivo. Our study suggested that combinational usage of JAK3 inhibitors and MDM2 inhibitors may increase the drug benefit for T-ALL patients with PHF6 and JAK3 co-mutations. Disclosures No relevant conflicts of interest to declare.

Near-infrared (NIR) PbS quantum-dot (QD) light sources were prepared by combining a chip-on-board (COB) LED chip with a PbS QD solution and ultraviolet (UV) glue. A method through adjusting the ratio of QD solution to UV glue to optimize the performance of the light source and match chemicals absorption spectra was presented in this paper. The relationship and trade-offs between different QD–glue ratios of the PbS QD light sources and the performance parameters including light intensity and PL peak were investigated at external voltages from 12.4 V to 13.4 V. The experimental results suggest that the PbS QD light intensity was the highest when the QD–glue ratio was 1:9. The light source was stable when the QD–glue ratio no more than 1:9. The PL peak of the QD light source were redshifted as the QD-glue ratio increased. In addition, two QDs materials with PL peak of 1172 ± 20 nm and 1380 ± 50 nm were selected to prepare the light source. The PL peak of the QD light source can match the absorption peak of the simulants of chemical warfare agents including Dimethyl Methylphosphonate (DMMP) and Dichloromethane (CH2Cl2) accurate by changing the QD-glue ratio. The results suggest that the QD light source optimized were match the sample well, which achieved qualitative detection. And the standard curves were establish, realized the quantitative detection of the sample concentration from 2% to 100%. Therefore, adjusting the QD–glue ratio is a feasible and effective method to improve the luminous intensity, the stability, and the Selectivity of sample detection of the QD light source. And the QDs with tunable emissions have great potential for multiple chemicals detect

Acute myeloid leukemia (AML) is an aggressive form of hematologic malignancies, caused by the accumulation of immature leukemic blasts in the hematopoietic system. Current chemotherapy regimens remain ineffective as assessed by low remission rate and 5-year-survival rate. MLL-AF9 mutations occur in approximately 10% of all acute leukemia patients, and are associated with poor therapy response and prognosis. Deregulated expression of ELAV-like family protein 2 (CELF2) has been identified in AML patients with MLL-AF9. As an RNA binding protein, CELF2 has been shown to regulate RNA splicing and embryonic hematopoietic development. However, the role of CELF2 in AML progression is still largely unknown. In this study, we first analyzed genetic data of 160 AML cases in the Cancer Genome Atlas in which CELF2 deletion account for 10% of the total cases. The survival time of patients with CELF2 deletion was much shorter than that of the others (P < 0.001). Interestingly, the expression of CELF2 was significantly decreased in different sub-type of acute myeloid leukemia cells, and the lowest expression of CELF2 was seen in MLL-AF9 (MA9) AML cells, when compared with that of normal myeloid cells. These results suggested that CELF2 deletion/mutation may play an important regulatory role in MA9-induced AML progression. To evaluate the potential role of Celf2 in the hematopoietic malignant transformation, we generated hematopoietic specific Celf2-deficient mice (Vav1-Cre;Celf2fl/fl) and found that Celf2-deficient hematopoietic stem cells (HSCs) over-expanded upon transplantation indicating a role of Celf2 in HSC proliferation. Consequently, the percentage of Celf2-KO HSC-derived myeloid cells was significantly increased in peripheral blood and bone marrow of recipient mice when compared with that of control mice. Celf2-KO Lin- cells were then infected by MA9-containing retrovirus and transplanted into lethally irradiated mice to generate Celf2-KO+MA9 mice. All Celf2-KO+MA9 mice succumbed to AML in 35 days, and their survival time is shorter than that of Celf2-WT+MA9 mice. The Celf2-KO+MA9 mice showed more aggressive phenotypes of AML than Celf2-WT+MA9 mice, including higher counts of WBCs, neutrophils and lymphocytes in peripheral blood, as well as higher extramedullar infiltration in spleen, liver and lung. To quantify the functional LSCs in Celf2-KO+MA9 mice and control MA9 mice, extreme limiting dilution transplantation assay was performed. The penetrance rate of leukemia in mice that received 1x103Celf2-KO+MA9 cells was significantly higher than that of control mice (100% versus 50%). The frequency of functional LSCs was significantly increased in Celf2-KO+MA9 mice as compared to that of the control, supporting a role of loss of Celf2 in promoting leukemia blast self-renewal. To investigate the underlying molecular mechanisms of Celf2 deletion in accelerating MA9 AML progression, we performed RNAseq to analyze the transcriptome programing changes associated with Celf2 in isogenic Celf2-WT+MA9 or Celf2-KO+MA9 AML cells. Consistent with severe extramedullar infiltration of leukemia cells in Celf2-KO+MA9 mice, gene set enrichment analysis showed up-regulated leukocyte activation and migration in Celf2-KO+MA9 leukemia cells. We next analyzed the downstream signaling pathways targeted by Celf2, and found that the phosphorylation of S6 was increased in Celf2-KO+MA9 cells, suggesting that Celf2 deletion might promote leukemia progression by activating mTORC1 signaling pathway. To confirm this, we treated Celf2-KO+MA9 mice with MA9 inhibitor (EPZ5676) and mTORC1 inhibitor (Rapamycin), and found a collaborative response to the treatment with a significant attenuation in leukemia burden in vivo. In conclusion, we found that CELF2 low expression is associated with AML patients with MA9 mutation. Celf2 deletion in mice induced myeloid-biased differentiation of HSCs. Notably, Celf2 deficiency promoted MA9-induced AML progression by activating mTORC1 signaling pathway independent of MA9 signaling pathway. Combinational therapy with MA9 inhibitors and mTORC1 inhibitors could significantly decrease the Celf2-KO+MA9 leukemia progression in vivo, indicating that combinational usage the drugs may have synergistic benefit for MA9 AML patients with low CELF2 expression. Disclosures No relevant conflicts of interest to declare.

s Obviously, the complicated application environment such as the varied temperature, humidity and interfering gases would produce great influences towards sensing process of gas sensors. To address the environmental characteristics in gas sensing process, surface acoustic wave (SAW) sensing devices built by a fluoroalcoholpolysiloxane (SXFA) deposited along the SAW propagation path of delay-line-patterned device were characterized in specific environments. Larger sensitivity, excellent linearity, and lower limit of detection (LOD)of 0.12 mg/m3were achieved from the proposed sensing device towards organophosphorus dimethyl methyl phosphonate (DMMP). By varying the testing temperature (5°C∼45°C) and humidity (30∼80 %RH), the corresponding effect on sensor response was examined. Apparent crossed temperature and humidity sensitivity were observed in gas sensing process, andcorrespondingcauses were demonstrated in details. Also, the cross interference test from the interference gases and smoke in the background environment demonstrated excellent anti-interference ability owned in the proposed sensing devices. Additionally, the long-term stability test in 18 months was conducted to examine the fatigue life of the sensing chip at temperature of 25°C and humidity of 35 %RH. The concluded detection error was less than 8%. Moreover, the related mechanisms were also discussed.

Terahertz (THz) spectroscopy is a rapidly emerging technology in the field of analytical chemistry. THz spectroscopy shows substantial scientific potential given that numerous absorption and emission molecular lines of interest in the chemical sciences belong to this spectral region. This article focuses on the current research progress on the detection of harmful gases, pesticides, antibiotics, toxic chemical compounds, and drugs of abuse by THz spectroscopy. The article also analyzes the key factors used for the detection of toxic chemical compounds by THz spectroscopy.