High-sensitivity fiber-tip acoustic sensor with ultrathin gold diaphragm.

Miniature acoustic sensors with high sensitivity are highly desired for applications in medical photoacoustic imaging, acoustic communications and industrial nondestructive testing. However, conventional acoustic sensors based on piezoelectric, piezoresistive and capacitive detectors usually require a large element size on a millimeter to centimeter scale to achieve a high sensitivity, greatly limiting their spatial resolution and the application in space-confined sensing scenarios. Herein, by using single-crystal two-dimensional gold flakes (2DGFs) as the sensing diaphragm of an extrinsic Fabry-Perot interferometer on a fiber tip, we demonstrate a miniature optical acoustic sensor with high sensitivity. Benefiting from the ultrathin thickness (∼8 nm) and high reflectivity of the 2DGF, the fiber-tip acoustic sensor gives an acoustic pressure sensitivity of ∼300 mV/Pa in the frequency range from 100 Hz to 20 kHz. The noise-equivalent pressure of the fiber-tip acoustic sensor at the frequency of 13 kHz is as low as 62.8 µPa/Hz1/2, which is one or two orders of magnitude lower than that of reported optical acoustic sensors with the same size.

[Meta-analysis and trial sequential analysis of Tanreqing Injection in treatment of severe pneumonia in elderly].

This study aimed to systematically evaluate the effectiveness and safety of Tanreqing Injection in the treatment of severe pneumonia in the elderly. Eighteen randomized controlled trials(RCTs) involving 1 457 elderly patients with severe pneumonia were included in the study after conducting searches in both Chinese and English databases as well as clinical trial registration platforms. The quality of the included studies was assessed using the Cochrane risk of bias assessment tool. Meta-analysis were conducted using RevMan 5.4 and Stata 17 software, and trial sequential analysis(TSA) was performed using TSA 0.9.5.10 beta software. Meta-analysis results showed that compared with conventional western medicine treatment, Tanreqing Injection + conventional western medical significantly improved the clinical effectiveness in elderly patients with severe pneumonia(RR=1.26, 95%CI[1.20, 1.32], P<0.000 01), arterial oxygen partial pressure(SMD=6.23, 95%CI[3.29, 9.18], P<0.000 1), oxygenation index(SMD=11.72, 95%CI[4.41, 19.04], P=0.002), reduce procalcitonin(SMD=-6.16, 95%CI[-8.10,-4.21], P<0.000 01), C-reactive protein(SMD=-8.50, 95%CI[-11.05,-5.96], P<0.000 01), white blood cell count(SMD=-4.56, 95%CI[-5.73,-3.39], P<0.000 01), and shortened the duration of fever(SMD=-3.12, 95%CI[-4.61,-1.63], P<0.000 1), cough(SMD=-4.84, 95%CI[-6.90,-2.79], P<0.000 01), lung rales(SMD=-0.99, 95%CI[-1.54,-0.44], P=0.000 4), and mechanical ventilation time(SMD=-3.26, 95%CI[-5.03,-1.50], P=0.000 3), increase CD4~+ T-cell levels(SMD=6.73, 95%CI[5.23, 8.23], P<0.000 01) and CD8~+ T-cell levels(SMD=7.47, 95% CI[5.32, 9.61], P<0.000 01) with no significant adverse reactions. TSA confirmed the stability and reliability of the results related to clinical effectiveness. This study suggests that Tanreqing Injection, as a Chinese medicinal preparation, has a significant therapeutic effect and good safety profile in the treatment of severe pneumonia in elderly patients. Due to the limited quality of the included studies, high-quality RCT is still needed to provide evidence support for the above conclusions.

Cryobacterium soli sp. nov., isolated from forest soil.

A taxonomic study was performed on strain GCJ02T, which was isolated from forest soil from Baishan City, PR China. The bacterium was Gram-stain-positive, catalase-positive and weakly oxidase-positive, rod-shaped and non-motile. Growth was observed at salinities of 0-6.0 % and at temperatures of 4-26 °C. Phylogenetic analysis based on 16S rRNA gene sequences indicated that GCJ02T represented a member of the genus Cryobacterium, with the highest sequence similarity to Cryobacterium arcticum SK1T (99.5 %) and Cryobacterium zongtaii TMN-42T (99.5 %), followed by Cryobacterium psychrotolerans CGMCC 1.5382T (97.7 %), and other species of the genus Cryobacterium (96.4-96.9 %). The ANI and the DNA-DNA hybridization estimate values between GCJ02T and all type strains of species of the genus Cryobacterium were 72.5-84.5 % and 19.6-28.7 %, respectively. The principal fatty acids (>10 %) of GCJ02T were anteiso-C15 : 0(53.0 %) and anteiso-C17 : 0 (18.8 %). The G+C content of the chromosomal DNA was 68.4 mol%. The respiratory quinone was determined to be MK-10. Phosphatidylglycerol, diphosphatidylglycerol, glycolipid, and one unidentified phospholipid and three unidentified polar lipid were present. The combined genotypic and phenotypic data indicated that strain GCJ02T represents a novel species within the genus Cryobacterium, for which the name Cryobacterium soli sp. nov. is proposed, with the type strain GCJ02T (=MCCC 1K03549T=JCM 32391T).

Functional Analysis of a Glutamine Biosynthesis Protein from a Psychrotrophic Bacterium, Cryobacterium soli GCJ02.

A putative glutamine synthetase (GS) was detected in a psychrophilic bacterium, Cryobacterium soli GCJ02. For gaining greater insight into its functioning, the gene was cloned and expressed in a heterologous host, Escherichia coli. The monomer enzyme with a molecular weight of 53.03 kDa was expressed primarily in cytosolic compartment. The enzyme activity was detected using glutamate and ATP. The optimum conditions of its biosynthesis were observed to be 60 °C and pH value 7.5. Its thermostability was relatively high with a half-life of 50 min at 40 °C. GS activity was enhanced in the presence of metal ions such as Mg2+ and Mn2+, whereas Fe2+, Cu2+ and Ca2+ proved inhibitory. The consensus pattern [EXE]-D-KP-[XGXGXH] in the GS lies between residues 132 and 272. The catalytic active sites consisting of EAE and NGSGMH were verified by site-directed mutagenesis. Based on the analysis of the consensus pattern, the GS/glutamate synthase cycle of C. soli GCJ02 is expected to contribute to the GS synthesic activity.

Green Synthesis of the Flavor Esters with a Marine Candida parapsilosis Esterase Expressed in Saccharomyces cerevisiae.

The green synthesis of the flavor esters, n-propyl acetate, isobutyl acetate and isoamyl acetate had the advantages over the chemical synthesis. The esterase from Candida parapsilosis could transform n-propanol, isobutanol and isoamyl alcohol into n-propyl acetate, isobutyl acetate and isoamyl acetate, respectively. The esterase was expressed in Saccharomyces cerevisiae. At 30 °C for 1 d, the concentration of n-propyl acetate, isobutyl acetate and isoamyl acetate synthesized by the esterase expressed in Saccharomyces cerevisiae was 24.6 mg/100 mL, 8.3 mg/100 mL, 5.6 mg/100 mL, respectively. Expression of the esterase has a practical significance for flavor ester synthesis by green biochemical process.

Full recycling of citric acid wastewater through anaerobic digestion, air-stripping and pH control.

Anaerobic digestion effluent (ADE) from the anaerobic digestion treatment of citric acid wastewater can be reused as a potential substitute for process water in the citric acid fermentation. However, excessive sodium contained in ADE significantly decreases citric acid production. In this paper, the inhibition mechanism of sodium on citric acid fermentation was investigated. We demonstrated that excessive sodium did not increase oxidative stress for Aspergillus niger, but reduced the pH of the medium significantly over the period 4-24 h, which led to lower activities of glucoamylase and isomaltase secreted by A. niger, with a decrease of available sugar concentration and citric acid production. ADE was pretreated by air-stripping prior to recycle and 18 g/L calcium carbonate was added at the start of fermentation to control the pH of the medium. The inhibition caused by ADE was completely alleviated and citric acid production substantially increased from 118.6 g/L to 141.4 g/L, comparable to the fermentation with deionized water (141.2 g/L). This novel process could decrease wastewater discharges and fresh water consumption in the citric acid industry, with benefit to the environment.

[Identification of bear bile powder and its adulterants by using DNA barcoding technology].

To identify the precious bile powder and its adulterants by DNA barcoding, and establish its standard experimental process to ensure the safe and effective utilization. Total twelve sequences from samples of bear bile powder which come from Ursus thibetanus for DNA extraction, PCR(polymerase chain reaction) and sequence, then using CodonCode Aligner V 7.0.1 shear primer region to obtain COI sequence. The COI sequences of U. arctos and their adulterants were obtained from GenBank. MEGA7.0 software was applied for analyzing mutation, calculating intraspecific and interspecific K2P(Kimura 2-Parameter) genetic distance and constructing the Neighbor-joining tree(NJ). The results showed that the maximum K2P genetic distance of bear bile powder of U. thibetanus and U. arctos are far less than minimum K2P genetic distance within its adulterants species, and the results of NJ tree demonstrated that each species could be distinguished from the counterfeits obviously. DNA barcoding is a safe, convenient and reliable technique for species identification, and it is important to establish the standard sequence of COI sequences for animal medicines.

[Primary exploration of key influential factors recognization method of Tanreqing injection].

To recognize the key influential factors during the liquid preparation process of Tanreqing injection, the near infrared(NIR) spectra of the raw materials and the operating parameters of 24 batches of physical manufacturing were recorded as independent variables, and the total soluble solids contents and the light inspection acceptance rate of the final products were collected as dependent variables. The calibration models were developed using the partial least-square regression (PLSR) method, and the correlation coefficients between the independent variables and the dependent variables were calculated. For the quantitative models, the correlation coefficients for the calibration and inner cross validation of total soluble solids contents and the light inspection acceptance rate reached 0.911 9, 0.724 2 and 0.873 8, 0.795 9, respectively. Using the correlation coefficients diagrams, several key influence factors were preliminarily determined, and the physical significance were analyzed combined with production experience. This work demonstrated that NIR spectroscopy with PLSR algorithm could be used for the key influential factors recognization during the liquid preparation process of Tanreqing injection and can be popularized to solve similar problems..

Total Synthesis of the Hamigerans.

The first total synthesis of hamigerans D, G, L, and N-Q has been accomplished. A convergent approach was used to build the basic tricarbocyclic ring system bearing a 5-6-6 structure. A sequence of oxidative cleavage, homologation, and ring regeneration provided access to the 5-7-6 skeleton of hamigeran G. Based on the biogenetic hypothesis, elegant and highly efficient biomimetic transformations of hamigeran G into hamigerans D, N-Q, and L were achieved.

[NIRS-based total quality control system construction of Tanreqing injection and relative thinking].

In this paper, NIRS (near infrared spectroscopy)-based total quality control system for the Tanreqing injection was introduced briefly. By analyzing and summing up the significance and difficulties, several important problems of the practical applications which need urgent solutions are proposed. And also the applicationprospect of NIRS is fully discussed and put forward in the end.

[Technological parameter optimization method for washing of coarse bear gall powder extracts based on NIR spectroscopy].

During the washing process of coarse bear gall powder extracts, it is necessary to adjust the amount of ethyl acetate according to the properties of raw materials, which aims to improving the yield and purity of the final product. In the research, using NIR spectra to reflect the comprehensive properties of coarse bear gall powder extracts, the process is optimized in a flexible way. Forty batches experiments are designed according to the weight ratio of ethyl acetate and coarse extracts of bear gall powder. The NIR spectra of the coarse extracts of bear gall powder are collected and processed using principal component analysis (PCA) method. The first 8 principal components combined with the amount of the ethyl acetate are used as the input variables, and calibration models are established to predict the yield and purity of the final product 30 batches are used as calibration set, which is used to establish the models, and other 10 batches are used as validation set, which is used for the performance appraisal of the established models. The correlation coefficients of the calibration, inner cross-validation and external validation for the purity model are 0.902, 0.896 and 0.883, respectively, and the RMSEC, RMSECV and RMSEP are 1.22%, 1.48% and 1.59%, respectively. The correlation coefficients of the calibration, inner cross-validation and external validation for the yield model are 0.921, 0.859 and 0.916, respectively, and the RMSEC, RMSECV and RMSEP are 1.39%, 1.65% and 1.53% respectively. This work demonstrated that NIR spectra combined with technology parameter could be used to predict the yield and purity of the final product. Using the established models, the most appropriate amount of the ethyl acetate can be determined according to the properties of the coarse bear gall powder extracts, and the yield and purity of the final product can be improved.

Zearalenone degrading enzyme evolution to increase the hydrolysis efficiency under acidic conditions by the rational design.

Based on rational design, zearalenone degrading enzyme was evolved to improve the hydrolysis efficiency under acidic conditions. At pH 4.2 and 37 °C, the activity of the zearalenone degrading enzyme evolved with 8 mutation sites increased from 7.69 U/mg to 38.67 U/mg. Km of the evolved zearalenone degrading enzyme decreased from 283.61 µM to 75.33 µM. The evolved zearalenone degrading enzyme was found to effectively degrade zearalenone in pig stomach chyme. Molecular docking revealed an increase in the number of hydrogen bonds and π-sigma interactions between the evolved zearalenone degrading enzyme and zearalenone. The evolved zearalenone degrading enzyme was valuable for hydrolyzing zearalenone under acidic conditions.

Production of acetic acid from wheat bran by catalysis of an acetoxylan esterase.

In this study, a gene encoding for acetylxylan esterase was cloned and expressed in E. coli. A single uniform band with molecular weight of 31.2 kDa was observed in SDS-PAGE electrophoresis. Served as the substrate, p-nitrophenol butyrate was employed to detect the recombinant enzyme activity. It exhibited activity at a wide temperature range (30-100 °C) and pH (5.0-9.0) with the optimal temperature of 70 °C and pH 8.0. Acetylxylan esterase showed two substrates' specificities with the highest Vmax of 177.2 U/mg and Km of 20.98 mM against p-nitrophenol butyrate. Meanwhile, the Vmax of p-nitrophenol acetate was 137.0 U/mg and Km 12.16 mM. The acetic acid yield of 0.39 g/g was obtained (70 °C and pH 8.0) from wheat bran pretreated using amylase and papain. This study showed the highest yield up to date and developed a promising strategy for acetic acid production using wheat bran.

[Quality control of Lonicerae japonicae flos with standard reference extract].

The high price of the reference substances is an obstacle for the HPLC analysis of Lonicerae Japonicae Flos. To solve this problem, a new method based on the standard reference extract (SRE) was proposed. In this study, the extract of Lonicerae Japonicae Flos was calibrated, and the long-term stability was investigated. Different concentration solutions of SRE were prepared for establishment of the calibration profiles, and 6 organic acids were determined. T-test was used for the comparison of the determination results via reference substances and SRE, and the results demonstrated that there is no significant difference between the two methods. The presented method can be used for the quality control of Lonicerae Japonicae Flos, and will also offer reference to resolve similar problems.

Concurrent production of ferulic acid and glucose from wheat bran by catalysis of a putative bifunctional enzyme.

The aim of this work is to study a bifunctional endoglucanase/carboxylesterase in Sphingobacterium soilsilvae Em02 and express it in soluble form in engineered Escherichia coli. The molecular weight of the recombinant protein of the bifunctional enzyme was 41 KDa. This research also determined the enzymatic activities of the bifunctional enzymes using microcrystalline cellulose and p-nitrophenyl butyrate as substrates and found 40 °C as the optimum temperature for their enzymatic activities. The optimal pH in dual function was 6.0 for endoglucanase and 7.0 for carboxylesterase. The bifunctional enzyme also exhibited enzymatic activities on the natural biomass by generating up to 3.94 mg of glucose and 49.4 µg of ferulic acid from 20 mg of destarched wheat bran. This indicates the broad application prospects of the bifunctional enzyme in agriculture and industry.

Genetic engineering for biohydrogen production from microalgae.

The development of biohydrogen as an alternative energy source has had great economic and environmental benefits. Hydrogen production from microalgae is considered a clean and sustainable energy production method that can both alleviate fuel shortages and recycle waste. Although algal hydrogen production has low energy consumption and requires only simple pretreatment, it has not been commercialized because of low product yields. To increase microalgal biohydrogen production several technologies have been developed, although they struggle with the oxygen sensitivity of the hydrogenases responsible for hydrogen production and the complexity of the metabolic network. In this review, several genetic and metabolic engineering studies on enhancing microalgal biohydrogen production are discussed, and the economic feasibility and future direction of microalgal biohydrogen commercialization are also proposed.

Ferulic acid production from wheat bran by integration of enzymatic pretreatment and a cold-adapted carboxylesterase catalysis.

High-value chemical production from natural lignocellulose transformation is a reliable waste utilization approach. A gene encoding cold-adapted carboxylesterase in Arthrobacter soli Em07 was identified. The gene was cloned and expressed in Escherichia coli to obtain a carboxylesterase enzyme with a molecular weight of 37.2 KDa. The activity of the enzyme was determined using α-naphthyl acetate as substrate. Results showed that the optimum enzyme activity of carboxylesterase was at 10 °C and pH 7.0. It was also found that the enzyme could degrade 20 mg enzymatic pretreated de-starched wheat bran (DSWB) to produce 235.8 µg of ferulic acid under the same conditions, which was 5.6 times more than the control. Compared to the chemical strategy, enzymatic pretreatment is advantageous because it is environmentally friendly, and the by-products can be easily treated. Therefore, this strategy provides an effective method for high-value utilization of biomass waste in agriculture and industry.

[A new method for simultaneous assay of six organic acids in Lonicerae Japonicae Flos].

OBJECTIVE: To establish a method of quantitative analysis of multi-components by single marker(QAMS) for quality control of Lonicerae Japonicae Flos. METHODS: The contents of chlorogenic acid(CA) and caffeic acid(CfA) were determined, and the relative correction factors(RCF) of other organic acids were calculated, which were used for the indirect determination. RESULTS: The RCFs for the neochlorogenic acid(NCA), 3, 4-O-dicaffeoylquinic acid(3, 4-DCA), 3, 5-O-dicaffeoylquinic acid(3, 5-DCA), and 4, 5-O-dicaffeoylquinic acid(4, 5-DCA) were 5.462, 5.689, 2.313, 2.382(to CA) and 3.941, 4.103, 1.669, 1.718(to CfA), respectively. The established method was validated in different laboratories with different high performance liquid chromatography(HPLC) instruments and different chromatographic columns; the result indicated that the reproducibility was satisfactory. There was no significant difference between the established QAMS method and external reference method (P>0.05). CONCLUSION: The established QAMS method can be used for simultaneous determination of 6 organic acids as quality control of Lonicerae Japonicae Flos with easy available standard substances.

Genetic manipulation strategies for ethanol production from bioconversion of lignocellulose waste.

Lignocellulose waste was served as promising raw material for bioethanol production. Bioethanol was considered to be a potential alternative energy to take the place of fossil fuels. Lignocellulosic biomass synthesized by plants is regenerative, sufficient and cheap source for bioethanol production. The biotransformation of lignocellulose could exhibit dual significance-reduction of pollution and obtaining of energy. Some strategies are being developing and increasing the utilization of lignocellulose waste to produce ethanol. New technology of bioethanol production from natural lignocellulosic biomass is required. In this paper, the progress in genetic manipulation strategies including gene editing and synthetic genomics for the transformation from lignocellulose to ethanol was reviewed. At last, the application prospect of bioethanol was introduced.

[An authentication method of bear bile powder based on the near infrared spectroscopy].

A method based on the near infrared (NIR) spectroscopy was established for the authentication of bear bile powder and the quantitative analysis of the proportion in the counterfeits. The NIR spectra of 30 bear bile powder samples from 4 different origins, 6 pig gall powder samples, and 65 mixed samples of bear bile powder and pig gall powder with different proportions range from 0 to 100% were collected. The principal component analysis (PCA) was done and well-marked boundaries were observed between the bear bile and the counterfeits, also the bear bile samples from different origins. Partial least squares discriminant analysis (PLS-DA) was used to differentiate the bear bile and the counterfeits, and the rate of accuracy is 95%. Finally, the PLS calibration model was established for the quantitative analysis of the bear bile proportion in the counterfeits, the coefficient of determination of the prediction set is 0.9759, and the root-mean-square prediction error is 4.25%, which indicated that the result was satisfied. This research contributes to the rapid and undamaged identification of bear bile powder, and also offers reference for the quality identification of other expensive medicinal materials.