Can algae-based technologies be an affordable green process for biofuel production and wastewater remediation?

Algae is a well-known organism that its characteristic is prominent for biofuel production and wastewater remediation. This critical review aims to present the applicability of algae with in-depth discussion regarding three key aspects: (i) characterization of algae for its applications; (ii) the technical approaches and their strengths and drawbacks; and (iii) future perspectives of algae-based technologies. The process optimization and combinations with other chemical and biological processes have generated efficiency, in which bio-oil yield is up to 41.1%. Through life cycle assessment, algae bio-energy achieves high energy return than fossil fuel. Thus, the algae-based technologies can reasonably be considered as green approaches. Although selling price of algae bio-oil is still high (about $2 L^-1) compared to fossil fuel's price of $1 L^-1, it is expected that the algae bio-oil's price will become acceptable in the next coming decades and potentially dominate 75% of the market.

Bioprocessing for elimination antibiotics and hormones from swine wastewater

Antibiotics and hormones in swine wastewater have become a critical concern worldwide due to the severe threats to human health and the eco-environment. Removal of most detectable antibiotics and hormones, such as sulfonamides (SAs), SMs, tetracyclines (TCs), macrolides, and estrogenic hormones from swine wastewater utilizing various biological processes were summarized and compared. In biological processes, biosorption and biodegradation are the two major removal mechanisms for antibiotics and hormones. The residuals in treated effluents and sludge of conventional activated sludge and anaerobic digestion processes can still pose risks to the surrounding environment, and the anaerobic processes' removal efficiencies were inferior to those of aerobic processes. In contrast, membrane bioreactors (MBRs), constructed wetlands (CWs) and modified processes performed better because of their higher biodegradation of toxicants. Process modification on activated sludge, anaerobic digestion and conventional MBRs could also enhance the performance (e.g. removing up to 98% SMs, 88.9% TCs, and 99.6% hormones from wastewater). The hybrid process combining MBRs with biological or physical technology also led to better removal efficiency. As such, modified conventional biological processes, advanced biological technologies and MBR hybrid systems are considered as a promising technology for removing toxicants from swine wastewater.

An efficient two-photon fluorescent probe for monitoring mitochondrial singlet oxygen in tissues during photodynamic therapy

A promising two-photon fluorescent probe MNAH for detecting ¹O₂ during the PDT process in mitochondria was proposed for the first time. MNAH was successfully applied for two-photon imaging of ¹O₂ in living cells and tissues during the PDT process with deep-tissue imaging depth. MNAH can be a powerful molecular tool for studying ¹O₂ generation in mitochondria during the PDT process.

Nanoscale zeolitic imidazole framework-90: selective, sensitive and dual-excitation ratiometric fluorescent detection of hazardous Cr(vi) anions in aqueous media

Toxic Cr(vi) anions sensing in aqueous solution has been achieved by virtue of fluorescent nanoscale ZIF-90 and RhB@ZIF-90.

Effects of C/N ratio on the performance of a hybrid sponge-assisted aerobic moving bed-anaerobic granular membrane bioreactor for municipal wastewater treatment

This study aimed to evaluate the impact of C/N ratio on the performance of a hybrid sponge-assisted aerobic moving bed-anaerobic granular membrane bioreactor (SAAMB-AnGMBR) in municipal wastewater treatment. The results showed that organic removal efficiencies were above 94% at all C/N conditions. Nutrient removal was over 91% at C/N ratio of 100/5 but was negatively affected when decreasing C/N ratio to 100/10. At lower C/N ratio (100/10), more noticeable membrane fouling was caused by aggravated cake formation and pore clogging, and accumulation of extracellular polymeric substances (EPS) in the mixed liquor and sludge cake as a result of deteriorated granular quality. Foulant analysis suggested significant difference existed in the foulant organic compositions under different C/N ratios, and humic substances were dominant when the fastest fouling rate was observed. The performance of the hybrid system was found to recover when gradually increasing C/N ratio from 100/10 to 100/5.

Recent progresses in small-molecule enzymatic fluorescent probes for cancer imaging

An overview of recent advances in small-molecule enzymatic fluorescent probes for cancer imaging, including design strategies and cancer imaging applications.

An MTH1-targeted nanosystem for enhanced PDT via improving cellular sensitivity to reactive oxygen species

An MTH1-targeted nanosystem is developed for enhanced PDT through inhibiting MTH1 protein and improving cellular sensitivity to reactive oxygen species.

[Diagnostic value of magnetic resonance imaging for middle ear cholesteatoma: a Meta-analysis]

Objective:To evaluate the values of magnetic resonance (MR) in the diagnosis of middle ear cholesteatoma by meta-analysis. Method:The articles concerning the diagnosis of middle ear cholesteatoma by using MRI until September 2017 were searched in databases including The Cochrane Library, PubMed, CBM, VIP, Wan Fang Data and CNKI with the search term "cholesteatoma, MR, Magnetic Resonance". Two independent researchers screened literature, extracted data, and assessed the risk of the bias of included studies with the inclusion and exclusion criteria using the QUADAS-2 tool. Then, meta-analysis was performed using Stata 12.0 software. The pooled weighted sensitivity and specificity were calculated, the summary receiver operating characteristic curve (SROC) was drawn and the area under the curve was calculated. Result:A total of 21 original studies were included. The results of meta-analysis showed that the pooled sensitivity, specificity, DOR and area under SROC curve of MR for diagnosing middle ear cholesteatoma were 0.88 (95%CI0.83 to 0.92), 0.91 (95%CI0.86 to 0.95), 10.13 (95%CI6.20 to 15.55), 0.13 (95%CI0.09 to 0.19), 79.23 (95%CI37.74 to 166.33), and 0.96 (95%CI0.93 to 0.97), respectively. The 1.5T MR has little differences with 1.5T MR in diagnosing middle ear cholesteatoma. In contrast to retrospective studies, prospective studies have further demonstrated that MR has a higher diagnostic value for middle ear cholesteatoma. Based on regions, the analysis showed that MR in Europe was more valuable in the diagnosis of middle ear cholesteatoma. Conclusion:In the diagnosis of middle ear cholesteatoma, MR has a high value.

[Quantitative measurement of citric acid in urine using tandem liquid chromatography mass spectrometry]

Objective: To find a suitable method for the determination of citric acid in the urine of patients with stones, in order to provide a new method and basis for the prevention and treatment of stone. Methods: Liquid chromatography tandem mass spectrometry was used to analyze the citric acid in urine directly. And the accuracy, stability, repeatability and other indicators of the results were detected. Results: The results showed a good linear relationship with the concentration of citric acid in urine. y=50.31x+ 0.002 6 (R(2)=0.994 21). The results were stable, reproducible [intra-day (Coefficient of Variance) CV ≈1% and inter-day CV<10%], and the accuracy of which was comparable with that of the enzyme method (n=20, R=0.97). Conclusion: Using the method of this study to detect the content of citric acid in urine has the advantages of simple operation, good repeatability, accurate results, and low price. So it is worth to be popularized and applied in clinical practice.

[Role of adrenal vein sampling in differential diagnosis of primary aldosteronism subtypes]

Objective: To investigate the role of adrenal vein sampling (AVS) in identifying the subtype of primary aldosteronism (PA). Methods: AVS was performed in 50 patients who were confirmed as PA between September 2010 and September 2016 in Nanjing Drum Tower Hospital. Clinical, biochemical and follow-up data were reviewed retrospectively. Bilaterally simultaneous catheterization without cosyntropin stimulation and contemporaneous cortisol measurement during AVS were used. Selectivity index (SI)≥1.5 suggested that the sample was from the adrenal vein.Lateralization index (LI) ≥2 suggested unilateral disease.Clinical data was further compared and the AVS findings were analyzed. Results: AVS was successful performed in 41 cases of 50 patients, and the success rate was 82%. According to the results of AVS and postoperative pathology, 41 cases were divided into aldosterone-producing adenoma (APA)/unilateral adrenal hyperplasia (UAH) group (24 cases) and idiopathic hyperaldosteronism (IHA) group (17 cases). Compared with IHA group, patients with APA/UAH showed longer duration of hypertension[10.0 (5.0, 13.0) y vs 4.0 (2.0, 8.0) y, P=0.046], higher proportion of hypokalemia (95.8% vs 64.7%, P=0.009). Furthermore, patients with APA/UAH demonstrated lower plasma renin activity (P=0.089), higher plasma aldosterone concentration and aldosterone to renin ratio (ARR) (both P<0.05). The diagnostic concordance between CT and adrenal vein sampling was only 48.8%(20/41). Conclusions: The application of bilaterally simultaneous catheterization and contemporaneous cortisol measurement improves success rate and diagnostic accuracy of AVS. AVS is useful in subtype diagnosis of PA with equivocal imaging findings.

A mitochondrial-targeted prodrug for NIR imaging guided and synergetic NIR photodynamic-chemo cancer therapy

Nontoxic prodrugs, especially activated by tumor microenvironment, are urgently required for reducing the side effects of cancer therapy. And combination of chemo-photodynamic therapy prodrugs show effectively synergetic therapeutic efficiency, however, this goal has not been achieved in a single molecule. In this work, we developed a mitochondrial-targeted prodrug PNPS for near infrared (NIR) fluorescence imaging guided and synergetic chemo-photodynamic precise cancer therapy for the first time. PNPS contains a NIR photosensitizer (NPS) and an anticancer drug 5'-deoxy-5-fluorouridine (5'-DFUR). These two parts are linked and caged through a bisboronate group, displaying no fluorescence and very low cytotoxicity. In the presence of H2O2, the bisboronate group is broken, resulting in activation of NPS for NIR photodynamic therapy and activation of 5'-DFUR for chemotherapy. The activated NPS can also provide a NIR fluorescence signal for monitoring the release of activated drug. Taking advantage of the high H2O2 concentration in cancer cells, PNPS exhibits higher cytotoxicity to cancer cells than normal cells, resulting in lower side effects. In addition, based on its mitochondrial-targeted ability, PNPS exhibits enhanced chemotherapy efficiency compare to free 5'-DFUR. It also demonstrated a remarkably improved and synergistic chemo-photodynamic therapeutic effect for cancer cells. Moreover, PNPS exhibits excellent tumor microenvironment-activated performance when intravenously injected into tumor-bearing nude mice, as demonstrated by in vivo fluorescence imaging. Thus, PNPS is a promising prodrug for cancer therapy based on its tumor microenvironment-activated drug release, synergistic therapeutic effect and "turn-on" NIR imaging guide.

Supramolecular assembly affording a ratiometric two-photon fluorescent nanoprobe for quantitative detection and bioimaging

Fluorescence quantitative analyses for vital biomolecules are in great demand in biomedical science owing to their unique detection advantages with rapid, sensitive, non-damaging and specific identification. However, available fluorescence strategies for quantitative detection are usually hard to design and achieve. Inspired by supramolecular chemistry, a two-photon-excited fluorescent supramolecular nanoplatform (TPSNP) was designed for quantitative analysis with three parts: host molecules (β-CD polymers), a guest fluorophore of sensing probes (Np-Ad) and a guest internal reference (NpRh-Ad). In this strategy, the TPSNP possesses the merits of (i) improved water-solubility and biocompatibility; (ii) increased tissue penetration depth for bioimaging by two-photon excitation; (iii) quantitative and tunable assembly of functional guest molecules to obtain optimized detection conditions; (iv) a common approach to avoid the limitation of complicated design by adjustment of sensing probes; and (v) accurate quantitative analysis by virtue of reference molecules. As a proof-of-concept, we utilized the two-photon fluorescent probe NHS-Ad-based TPSNP-1 to realize accurate quantitative analysis of hydrogen sulfide (H₂S), with high sensitivity and good selectivity in live cells, deep tissues and ex vivo-dissected organs, suggesting that the TPSNP is an ideal quantitative indicator for clinical samples. What's more, TPSNP will pave the way for designing and preparing advanced supramolecular sensors for biosensing and biomedicine.

[Quantitative measurement of oxalic acid in urine by liquid chromatography combined with tandem mass spectrometry]

Objective: To find a suitable method for the determination of oxalic acid in the urine of patients with stones, in order to provide a new method and basis for the prevention and treatment of stone. Methods: Liquid chromatography combined with tandem mass spectrometry was used to analyze oxalic acid in urine directly.The accuracy, stability, repeatability and other indicators of the results were tested. Results: The results showed a good linear relationship with the concentration of oxalic acid in urine. y=58.524x-15.246 (R(2)=0.979 02). The results were stable, reproducible (the intra-day and inter-day coefficient of variation was less than 10% and 15%, respectively), and the accuracy was comparable with that of the enzyme method (N=20, R=0.93). Conclusion: Using the method of this study to detect the content of oxalic acid in urine has the advantages of simple operation, good repeatability, accurate results, and low price. It is worth to be popularized and applied in clinical practice.

Aptamer-integrated DNA nanostructures for biosensing, bioimaging and cancer therapy

The combination of nanostructures with biomolecules leading to the generation of functional nanosystems holds great promise for biotechnological and biomedical applications. As a naturally occurring biomacromolecule, DNA exhibits excellent biocompatibility and programmability. Also, scalable synthesis can be readily realized through automated instruments. Such unique properties, together with Watson-Crick base-pairing interactions, make DNA a particularly promising candidate to be used as a building block material for a wide variety of nanostructures. In the past few decades, various DNA nanostructures have been developed, including one-, two- and three-dimensional nanomaterials. Aptamers are single-stranded DNA or RNA molecules selected by Systematic Evolution of Ligands by Exponential Enrichment (SELEX), with specific recognition abilities to their targets. Therefore, integrating aptamers into DNA nanostructures results in powerful tools for biosensing and bioimaging applications. Furthermore, owing to their high loading capability, aptamer-modified DNA nanostructures have also been altered to play the role of drug nanocarriers for in vivo applications and targeted cancer therapy. In this review, we summarize recent progress in the design of aptamers and related DNA molecule-integrated DNA nanostructures as well as their applications in biosensing, bioimaging and cancer therapy. To begin with, we first introduce the SELEX technology. Subsequently, the methodologies for the preparation of aptamer-integrated DNA nanostructures are presented. Then, we highlight their applications in biosensing and bioimaging for various targets, as well as targeted cancer therapy applications. Finally, we discuss several challenges and further opportunities in this emerging field.

Near Infrared Graphene Quantum Dots-Based Two-Photon Nanoprobe for Direct Bioimaging of Endogenous Ascorbic Acid in Living Cells

Ascorbic acid (AA), as one of the most important vitamins, participates in various physiological reactions in the human body and is implicated with many diseases. Therefore, the development of effective methods for monitoring the AA level in living systems is of great significance. Up to date, various technologies have been developed for the detection of AA. However, few methods can realize the direct detection of endogenous AA in living cells. In this work, we for the first time reported that near-infrared (NIR) graphene quantum dots (GQD) possessed good two-photon fluorescence properties with a NIR emission at 660 nm upon exciting with 810 nm femtosecond pulses and a two-photon (TP) excitation action cross-section (δΦ) of 25.12 GM. They were then employed to construct a TP nanoprobe for detection and bioimaging of endogenous AA in living cells. In this nanosystem, NIR GQDs (NGs), which exhibited lower fluorescence background in living system to afford improved fluorescence imaging resolution, were acted as fluorescence reporters. Also CoOOH nanoflakes were chosen as fluorescence quenchers by forming on the surface of NGs. Once AA was introduced, CoOOH was reduced to Co²⁺, which resulted in a "turn-on" fluorescence signal of NGs. The proposed nanoprobe demonstrated high sensitivity toward AA, with the observed LOD of 270 nM. It also showed high selectivity to AA with excellent photostability. Moreover, the nanoprobe was successfully used for TP imaging of endogenous AA in living cells as well as deep tissue imaging.

Automatic time-shift alignment method for chromatographic data analysis

Time shift among samples remains a significant challenge in data analysis, such as quality control of natural plant extracts and metabolic profiling analysis, because this phenomenon may lead to invalid conclusions. In this work, we propose a new time shift alignment method, namely, automatic time-shift alignment (ATSA), for complicated chromatographic data analysis. This technique comprised the following alignment stages: (1) automatic baseline correction and peak detection stage for providing useful chromatographic information; (2) preliminary alignment stage through adaptive segment partition to correct alignment for the entire chromatogram; and (3) precise alignment stage based on test chromatographic peak information to accurately align time shift. In ATSA, the chromatographic peak information of both reference and test samples can be completely employed for time-shift alignment to determine segment boundaries and avoid loss of information. ATSA was used to analyze a complicated chromatographic dataset. The obtained correlation coefficients among samples and data analysis efficiency indicated that the influences of time shift can be considerably reduced by ATSA; thus accurate conclusion could be obtained.

Tetraphenylethene derivative modified DNA oligonucleotide for in situ potassium ion detection and imaging in living cells

The monitoring of K⁺ is very important and emergency because of their unique relationship in various disease diagnosis and treatment. G-quadruplex analogue is a classical recognition unit for K⁺ detection and has been widely applied in K⁺ relevant research. Common fluorescent dyes were employed for design of G-quadruplex structure-based K⁺ probes which suffered from the aggregation-caused quenching effect, and possibly limited the biological applications in living systems. Herein, we report an aggregation-induced emission (AIE) effect-based fluorescent probe for cellular K⁺ analysis and imaging. Benefitting from the K⁺ triggered AIE phenomenon, the designed TPE derivative modified guanine (G)-rich oligonucleotide fluorescent probe (TPE-oligonucleotide probe) exhibits high sensitivity (∼10-fold higher than most reported G-quadruplex-based probes) with extended photostability which facilitates the prolonged fluorescence observations of K⁺ in living cells. On the basis of these advantages, the TPE-oligonucleotide probe serves as a promising candidate for the functional study and analysis of K⁺.