Enhancement of bio-promoters on hexavalent chromium inhibited sulfur-driven denitrification: repairing damage, accelerating electron transfer, and reshaping microbial collaboration.

Proposing recovery strategies to recover heavy-metal-inhibited sulfur-driven denitrification, as well as disclosing recovery mechanisms, can provide technical support for the stable operation of bio-systems. This study proposed an effective bio-promoter (mediator-promoter composed of L-cysteine, biotin, cytokinin, and anthraquinone-2,6-disulfonate) to recover Cr(VI) inhibited sulfur-driven denitrification, which effectively reduced the recovery time of NO3--N reduction (18-21 cycles) and NO2--N reduction (27-42 cycles) compared with self-recovery. The mediator-promoter repaired microbial damage by promoting intracellular chromium efflux. Moreover, the mediator-promoter reduced the accumulated reactive oxygen species by stimulating the secretion of antioxidant enzymes, reaching equilibrium in the oxidative-antioxidant system. To improve electron transmission, the mediator-promoter restored S2O32- oxidation to provide adequate electron donors and increased electron transfer rate by increasing cytochrome c levels. Mediator-promoter boosted the abundance of Thiobacillus (sulfur-oxidizing bacterium) and Simplicispira (denitrifying bacterium), which were positively correlated, facilitating the rapid denitrification recovery and the long-term stable operation of recovered systems.

Recovery mechanism of bio-promoters on Cr(VI) suppressed denitrification: Toxicity remediation and enhanced electron transmission.

Although the biotoxicity of heavy metals has been widely studied, there are few reports on the recovery strategy of the inhibited bio-system. This study proposed a combined promoter-I (Primary promoter: l-cysteine, biotin, and cytokinin + Electron-shuttle: PMo12) to recover the denitrification suppressed by Cr(VI). Compared with self-recovery, combined promoter-I shortened the recovery time of 28 cycles, and the recovered reactor possessed more stable long-term operation performance with >95 % nitrogen removal. The biomass increased by 7.07 mg VSS/(cm3 carrier) than self-recovery due to the promoted bacterial reproduction, thereby reducing the toxicity load of chromium per unit biomass. The combined promoter-I strengthened the toxicity remediation by promoting 92.84 % of the intracellular chromium release and rapidly activating anti-oxidative stress response. During toxicity remediation, ROS content quickly decreased, and the PN/PS value was 2.27 times that of self-recovery. PMo12 relieved Cr(VI) inhibition on NO3--N reduction by increasing NAR activity. The enhanced intracellular and intercellular electron transmission benefited from the stimulated NADH, FMN, and Cyt.c secretion by the primary promoter and the improved transmembrane electron transmission by Mo. PMo12 and the primary promoter synergized in regulating community structure and improving microbial richness. This study provided practical approaches for microbial toxicity remediation and maintaining high-efficiency denitrification.

Exploring Advanced Functionalities of Carbon Fiber-Graded PEEK Composites as Bone Fixation Plates Using Finite Element Analysis.

This study aims to address the challenges associated with conventional metallic bone fixation plates in biomechanical applications, such as stainless steel and titanium alloys, including stress shielding, allergic reactions, corrosion resistance, and interference with medical imaging. The use of materials with a low elastic modulus is regarded as an effective approach to overcome these problems. In this study, the impact of different types of chopped carbon fiber-reinforced polyether ether ketone (CCF/PEEK) functionally graded material (FGM) bone plates on stress shielding under static and instantaneous dynamic loading was explored using finite element analysis (FEA). The FGM bone plate models were established using ABAQUS and the user's subroutine USDFLD and VUSDFLD, and each model was established with an equivalent overall elastic modulus and distinctive distributions. The results revealed that all FGM bone plates exhibited lower stress shielding effects compared to metal bone plates. Particularly, the FGM plate with an elastic modulus gradually increased from the centre to both sides and provided maximum stress stimulation and the most uniform stress distribution within the fractured area. These findings offer crucial insights for designing implantable medical devices that possess enhanced mechanical adaptability.

Nitrate Bioreduction under Cr(VI) Stress: Crossroads of Denitrification and Dissimilatory Nitrate Reduction to Ammonium.

This study explored the response of NO3--N bioreduction to Cr(VI) stress, including reduction efficiency and the pathways involved (denitrification and dissimilatory nitrate reduction to ammonium (DNRA)). Different response patterns of NO3--N conversion were proposed under Cr(VI) suppress (0, 0.5, 5, 15, 30, 50, and 80 mg/L) by evaluating Cr(VI) dose dependence, toxicity accumulation, bioelectron behavior, and microbial community structure. Cr(VI) concentrations of >30 mg/L rapidly inhibited NO3--N removal and immediately induced DNRA. However, denitrification completely dominated the NO3--N reduction pathway at Cr(VI) concentrations of <15 mg/L. Therefore, 30 and 80 mg/L Cr(VI) (R4 and R6) were selected to explore the selection of the different NO3--N removal pathways. The pathway of NO3--N reduction at 30 mg/L Cr(VI) exhibited continuous adaptation, wherein the coexistence of denitrification (51.7%) and DNRA (13.6%) was achieved by regulating the distribution of denitrifiers (37.6%) and DNRA bacteria (32.8%). Comparatively, DNRA gradually replaced denitrification at 80 mg/L Cr(VI). The intracellular Cr(III) accumulation in R6 was 6.60-fold greater than in R4, causing more severe oxidant injury and cell death. The activated NO3--N reduction pathway depended on the value of nitrite reductase activity/nitrate reductase activity, with 0.84-1.08 associated with DNRA activation and 1.48-1.57 with DNRA predominance. Although Cr(VI) increased microbial community richness and improved community structure stability, the inhibition or death of nitrogen-reducing microorganisms caused by Cr(VI) decreased NO3--N reduction efficiency.

New insights into hexavalent chromium exposure in electron donor limited denitrification: bio-electron behavior.

The bio-electron behavior (electron production, transmission, and consumption) response to a typical heavy metal, hexavalent chromium, was unraveled in the electron donor limited system (EDLS) and electron donor sufficient system (EDSS). Nicotinamide adenine dinucleotide and adenosine triphosphate production were reduced by 44% and 47%, respectively, due to glucose metabolism inhibition, leading to NO3--N declining to 31% in EDLS. The decreased electron carrier contents and denitrifying enzymes activity inhibited electron transmission and consumption in both EDLS and EDSS. Additionally, electron transfer and antioxidant stress abilities were reduced, further hindering the survival of denitrifiers in EDLS. The lack of dominant genera (Comamonas, Thermomonas, and Microbacterium) in EDLS was the primary reason for poor biofilm formation and chromium adaptability. The decreased expression of enzymes related to glucose metabolism caused the imbalance of electron supply, transport, and consumption in EDLS, adversely impacting nitrogen metabolism and inhibiting denitrification performance.

The Reaction Products of the Al-Nb-B2O3-CuO System in an Al 6063 Alloy Melt and Their Influence on the Alloy's Structure and Characteristics.

To meet aero-engine aluminum skirt requirements, an experiment was carried out using Al-Nb-B2O3-CuO as the reaction system and a 6063 aluminum alloy melt as the reaction medium for a contact reaction, and 6063 aluminum matrix composites containing in situ particles were prepared with the near-liquid-phase line-casting method after the reaction was completed. The effects of the reactant molar ratio and the preheating temperature on the in situ reaction process and products were explored in order to determine the influence of in situ-reaction-product features on the organization and the qualities of the composites. Thermodynamic calculations, DSC analysis, and experiments revealed that the reaction could continue when the molar ratio of the reactants of Al-Nb-B2O3-CuO was 6:1:1:1.5. A kinetic study revealed that the Al thermal reaction in the system produced Al2O3 and [B], and the [B] atoms interacted with Nb to generate NbB2. With increasing temperature, the interaction between the Nb and the AlB2 produced hexagonal NbB2 particles with an average longitudinal size of 1 µm and subspherical Al2O3 particles with an average longitudinal size of 0.2 µm. The microstructure of the composites was reasonably fine, with an estimated equiaxed crystal size of around 22 µm, a tensile strength of 170 MPa, a yield strength of 135 MPa, an elongation of 13.4%, and a fracture energy of 17.05 × 105 KJ/m3, with a content of 2.3 wt% complex-phase particles. When compared to the matrix alloy without addition, the NbB2 and Al2O3 particles produced by the in situ reaction had a significant refinement effect on the microstructure of the alloy, and the plasticity of the composite in the as-cast state was improved while maintaining higher strength and better overall mechanical properties, allowing for industrial mass production.

Acne and its post-inflammatory hyperpigmentation treatment by applying anti-acne dissolving microneedle patches.

OBJECTIVE: Acne is a significant problem in young people. At present, most acne treatment products are topically applied cosmetics, whose efficacy is limited by the stratum corneum. The dissolving microneedle technique can effectively deliver drug molecules into the body. In this study, dissolving microneedles containing anti-acne ingredients were tested for human efficacy and safety. METHODS: We conducted a 28-day clinical efficacy and safety trial on 30 individuals with visible facial acne. During the trial, anti-acne microneedle (AA-DMN) patches were applied to designated skin areas once daily for 28 consecutive days. Skin pigmentation was measured using a Courage + Khazaka skin melanin and hemoglobin test probe Mexameter MX18. Acne volume was measured using a Canfieldsci skin rapid optical imaging system PRIMOS. In addition, skin irritation was evaluated via self-report and dermatologist's examination. RESULTS: The AA-DMN patches showed good efficacy including improvement of skin pigmentation and reduced acne volume. Acne volume was reduced by 12.34% after 3 days of patch use and further reduced by 10.01% after 7 continuous days of use. After 28 days of treatment, skin melanin decreased by 5.88% and heme decreased by 7.83%. No adverse reactions were observed in any of the participants. CONCLUSIONS: Anti-acne microneedle patches showed an excellent effect in reducing acne and post-inflammatory hyperpigmentation (PIH), without adverse skin reactions. The novel AA-DMN patch is a safe and effective anti-acne treatment.

A new insight to explore toxic Cd(II) affecting denitrification: Reaction kinetic, electron behavior and microbial community.

Denitrification process is a crucial step in nitrogen removal and is more vulnerable to external shocks due to the fact that anoxic process is always located before aerobic process in conventional sewage treatment. This study aims to elaborate the nitrogen conversion characteristics by investigating denitrification kinetics, electron behavior and microbial community under Cd(II) shock. Reaction kinetics showed that 10 mg/L of Cd(II) accelerated nitrate reduction rate by 52.29% but 80 mg/L of Cd(II) severely decelerated it by 95.41% with the accumulation of nitrite. High concentration of COD (C/N = 10.4) in the system caused by Cd(II) disrupting the integrity of cell membrane (lactate dehydrogenase increased by 328.7%) was proved to induce occurrence of Dissimilatory Nitrate Reduction to Ammonia (DNRA). The electron transport system activity (ETSA), electron consumption and electron distribution were combined to reveal the electron behavior regulated by Cd(II). The electron ratio of nitrate reductase to nitrite reductase increased from 1.48 (control) to 3.91 and 3.52 (40 and 80 mg/L of Cd(II)) indicated the electrons allocating tendency and further explained the nitrite accumulation. High concentration of Cd(II) also decreased ETSA by weakening the physiological activities of flavin adenine dinucleotide, flavin mononucleotide and cytochrome c or hindered the microbes to secrete these electron carriers. Furthermore, Cd(II) inhibited dominant bacteria genera containing napA gene (Azospirillum and Thauera) and nirS gene (unclassified_c_Betaproteobacteria). Enterobacteriaceae family was found to dominate the DNRA process.

Plasma cfDNA for the Diagnosis and Prognosis of Colorectal Cancer.

Objective: To evaluate the value of cell-free DNA (cfDNA) for the diagnosis and prognosis of colorectal cancer (CRC). Methods: Peripheral blood specimens of 120 CRC patients and 90 healthy volunteers (as a control cohort) were extracted. A quantitative real-time polymerase chain reaction (qRT-PCR) was performed to determine the cfDNA expression. Following correlation analyses for cfDNA and clinical endpoints, a receiver operator characteristic (ROC) curve was established to assess the sensitivity and specificity of cfDNA, CEA, VEGF, and CA125 and for evaluating the disease-free survival (DFS) of patients. Results: The plasma cfDNA level of colorectal cancer patients was significantly higher than that of healthy subjects (P < 0.05), and after chemotherapy, cfDNA level was significantly lower than that before chemotherapy (P < 0.05). CA125/CEA/VEGF expression significantly correlated with cfDNA level, but not with cfDNA integrity. There was also a significant correlation between tumor differentiation and the cfDNA level. cfDNA has a higher ROC value than the current tumor biomarkers. Survival analysis showed that the DFS of the low cfDNA expression group was longer (29.99 ± 0.78 months) than that of the high cfDNA expression group (27.66 ± 1.05 months, P=0.031). Conclusion: The blood cfDNA is associated with the pathological features of CRC clinical cases and represents a possible indicator for CRC diagnosis and prognosis.

Induction of developmental toxicity and cardiotoxicity in zebrafish embryos by Emamectin benzoate through oxidative stress.

Emamectin benzoate (EMB) is a widely used pesticide in agriculture, but its potential risks to the environment and health have not been fully evaluated. In this study, we evaluated the toxicity of Emamectin benzoate using zebrafish model, and found that it affected early embryonic development, such as malformations and delayed hatching. Mechanistically, Emamectin benzoate increased oxidative stress by excessive production of reactive oxygen species (ROS) and abnormal activities of the antioxidant enzymes. Moreover, Emamectin benzoate exposure caused abnormalities in zebrafish heart morphology and function, such as long SV-BA distance and slow heart rate. Alterations were induced in the transcription of heart development-related genes (nkx2.5, tbx5, gata4 and myl7). In summary, our data showed that Emamectin benzoate induces developmental toxicity and cardiotoxicity in zebrafish. Our research provides new evidence on the Emamectin benzoate's toxicity and potential risk in human health.

Application oriented bioaugmentation processes: Mechanism, performance improvement and scale-up.

Bioaugmentation is an optimization method with great potential to improve the treatment effect by introducing specific strains into the biological treatment system. In this study, a comprehensive review of the mechanism of bioaugmentation from the aspect of microbial community structure, the optimization methods facilitating application as well as feasible approaches of scale-up application has been provided. The different contribution of indigenous and exogenous strains was critically analyzed, the relationship between microbial community variation and system performance was clarified. Operation regulation and immobilization technologies are effective methods to deal with the possible failure of bioaugmentation. The gradual expansion from lab-scale, pilot scale to full-scale, the transformation and upgrading of wastewater treatment plants through the combination of direct dosing and biofilm, and the application of side-stream reactors are feasible ways to realize the full-scale application. The future challenges and prospects in this field were also proposed.

Design, Manufacture and Test of Piezoelectric Cantilever-Beam Energy Harvesters with Hollow Structures.

This article presents a single-crystal piezoelectric energy harvester (PEH) with a trapezoidal hollow hole that can obtain high energy density at low frequency. Harvesters with a hollow structure were fabricated through a series of manufacturing processes such as thermocompression bonding, screen printing and laser cutting. Finite element analysis (FEA) and experimental results showed that using low modulus brass instead of stainless steel as the PEH substrate enhances the voltage output of the device, and the hollow design greatly increases the overall stress level and power density. In addition, the developed PEH with a trapezoidal hole obtained the best output performance; when the acceleration, resonance frequency and matched load resistance were 0.5 g, 56.3 Hz and 114 kΩ, respectively, the peak voltage was 17 V and the power density was 2.52 mW/cm3. Meanwhile, compared with the unhollowed device, the peak voltage and maximum power density of the proposed PEH were increased by 30.7% and 24.4%, respectively, and the resonance frequency was reduced by 7%. This study verified the feasibility of the optimized design through simulation and experimental comparison.

ADCK1 activates the ß-catenin/TCF signaling pathway to promote the growth and migration of colon cancer cells.

As a result of mutations in the upstream components of the Wnt/ß-catenin signaling pathway, this cascade is abnormally activated in colon cancer. Hence, identifying the activation mechanism of this pathway is an urgent need for the treatment of colon cancer. Here, we found an increase in ADCK1 (AarF domain-containing kinase 1) expression in clinical specimens of colon cancer and animal models. Upregulation of ADCK1 expression promoted the colony formation and infiltration of cancer cells. Downregulation of ADCK1 expression inhibited the colony formation and infiltration of cancer cells, in vivo tumorigenesis, migration, and organoid formation. Molecular mechanistic studies demonstrated that ADCK1 interacted with TCF4 (T-cell factor 4) to activate the ß-catenin/TCF signaling pathway. In conclusion, our research revealed the functions of ADCK1 in the development of colon cancer and provided potential therapeutic targets.

Compressive optical steganography via single-pixel imaging.

A compressive optical steganography based on single-pixel imaging (SPI) is proposed. The SPI system, which employs a digital light projector to illuminate the host image with modulated patterns, is similar to a wireless broadcast system. Therefore, it is suitable for covert communication naturally. By leveraging the compressive sensing technique and a generalized phase retrieval algorithm, the secret message is sparse-sampled and then encoded into the illumination patterns, which are projected onto the host image in an SPI architecture. The resulting reflected light signals travel in the free space as a broadcast system, and the signals would be captured by the authorized receivers and the potential eavesdroppers. By implementing an inverse Fourier transform, a stegoimage will be received, which is almost the same as the host image. However, only the authorized receivers, who possess the secret key, could extract the desired data from the stegoimage and then reconstruct the secret message by using a convex optimization algorithm. Because the secret message is sparse-sampled before embedding, the imperceptibility is well preserved while the capacity also be kept in a high level. A series of simulation and experimental results verifies the validity and feasibility of the proposed method.

Correction to: Effect of long non-coding RNA Gas5 on proliferation, migration, invasion and apoptosis of colorectal cancer HT-29 cell line.

[This corrects the article DOI: 10.1186/s12935-017-0478-7.].

Effect of long non-coding RNA Gas5 on proliferation, migration, invasion and apoptosis of colorectal cancer HT-29 cell line.

Objective: This study aims to investigate the effect of long non-coding RNA (lncRNA) Gas5 on proliferation, migration, invasion and apoptosis of colorectal cancer (CRC) HT-29 cell line. Methods: CRC and normal tissues were collected and prepared from a total of 126 CRC patients, and normal intestinal epithelial cell line FHC and CRC cell lines (HCT-8, HT-29, HCT-116 and SW-480) were prepared. Gas5 expression was detected by quantitative reverse transcriptase-polymerase chain reaction. HT-29 cell line exhibiting the lowest Gas5 expression was selected for further experimentation and divided into blank, negative control and pcNDA-Gas5 groups. The cell counting kit-8 assay was used to test cell proliferation. Flow cytometry was applied to examine cell apoptosis. Transwell assay was performed to detect the migration and invasion of HT-29 cells. The mRNA and protein expression of factors in the classical proliferation (Akt/Erk) and apoptosis (caspase-9/caspase-3) pathways were detected. Results: Gas5 expression was lower in CRC tissues compared to the adjacent normal tissues, and is also lower in CRC cell lines than FHC cell line. Gas5 expression was associated with tumor size and TNM staging. Gas5 expression, distant metastasis, tumor differentiation and TNM staging were independent CRC prognostic factors. The results showed that elevated Gas5 expression inhibited proliferation, migration and invasion, but promoted apoptosis of CRC cells. Meanwhile, elevated Gas5 expression inhibited mRNA expression of Akt and Erk and protein expression of p-Akt and p-Erk, which promoted Casp9 mRNA and pho-Casp9 protein expression but inhibited Casp3 mRNA and pho-Casp3 protein expression. Conclusion: The findings indicated that overexpression of lncRNA Gas5 can inhibit the proliferation, migration and invasion but promote apoptosis of CRC cells.

Vulnerability to ciphertext-only attack of optical encryption scheme based on double random phase encoding.

We demonstrate in this paper that the traditional double random phase encoding (DRPE) technique is vulnerable to ciphertext-only attack (COA). In this method, an unauthorized user (or say attacker) is assumed to be able to retrieve the corresponding plaintext from the only ciphertext under some certain condition. The proposed scheme mainly relies on a hybrid iterative phase retrieval (HIPR) algorithm, which combines various phase retrieval algorithms. With an estimation of the number of nonzero pixels (NNP) in the original plaintext, an attacker could recover the plaintext in a large extent. The simulation results show that this method is feasible and validate.

Optical cryptosystem based on phase-truncated Fresnel diffraction and transport of intensity equation.

A novel optical cryptosystem based on phase-truncated Fresnel diffraction (PTFD) and transport of intensity equation (TIE) is proposed. By using the phase truncation technique, a phase-encoded plaintext could be encrypted into a real-valued noise-like intensity distribution by employing a random amplitude mask (RAM) and a random phase mask (RPM), which are regarded as two secret keys. For decryption, a generalized amplitude-phase retrieval (GAPR) algorithm combined with the TIE method are proposed to recover the plaintext with the help of two keys. Different from the current phase-truncated-based optical cryptosystems which need record the truncated phase as decryption keys, our scheme do not need the truncated phase because of the introducing of the TIE method. Moreover, the proposed scheme is expected to against existing attacks. A set of numerical simulation results show the feasibility and security of the proposed method.

Hybrid organic-inorganic monolithic enzymatic reactor with SBA-15 nanoparticles incorporated.

A novel enzymatic reactor was prepared by incorporating SBA-15 nanoparticles into hybrid organic-inorganic monolith and immobilizing trypsin with glutaraldehyde as bridging reagent. Preparation and operation conditions including nanoparticles percentage and residence time were optimized to improve the digestion efficiency. The digestion products were characterized by Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF-MS) with sequence coverage of 50%, 93% and 71% for bovine serum albumin, myoglobin and cytochrome C, while consuming only about 19s in dynamic mode. Compared with enzymatic reactor without nanoparticles incorporated, the enzymatic reactor with SBA-15 nanoparticles embedded achieved higher digestion efficiency by introducing more trypsin, which was originated from combination of SBA-15 nanoparticles and hybrid organic-inorganic monolith.

Ciphertext-only attack on a joint transform correlator encryption system.

A ciphertext-only attack (COA) on a joint transform correlator (JTC) encryption system is proposed. From the perspective view of optical cryptanalysis, we find out that the issue to be solved in the COA scheme could be transferred into a phase retrieval problem with single intensity measurement. And in this paper, the hybrid input-output (HIO) algorithm is employed to handle this issue with the help of an inartificial signal domain support and a given frequency domain constraint. Meanwhile, we provide a set of numerical simulations to demonstrate the validity and feasibility of the presented method.